Krishnamurthy Bonanthaya Elavenil Panneerselvam Suvy Manuel Vinay V. Kumar Anshul Rai *Editors* 

# Oral and Maxillofacial Surgery for the Clinician

Oral and Maxillofacial Surgery for the Clinician

Krishnamurthy Bonanthaya Elavenil Panneerselvam • Suvy Manuel Vinay V. Kumar • Anshul Rai Editors

# Oral and Maxillofacial Surgery for the Clinician

*Editors* Krishnamurthy Bonanthaya Bhagwan Mahaveer Jain hospital Bangalore India

Suvy Manuel Ananthapuri Hospitals & Research Institute Kerala Institute of Medical Sciences Trivandrum, Kerala India

Anshul Rai Associate Professor Department of Dentistry All India Institute of Medical Sciences Bhopal, Madhya Pradesh India

*Video Editors* Jimson Samson Vice Principal Prof & Head of Department Department of Oral & Maxillofacial Surgery Tagore Dental College & Hospital Chennai, India

*Illustrator* Mr Brishank Pratap Goa, India

*Voice-over for Videos* Madhulaxmi Marimuthu Professor Saveetha Dental College Chennai, India

Vivek Narayanan Dean, SRM Dental College Kaatangulathur Chennai, India

This book is an open access publication. ISBN 978-981-15-1345-9 ISBN 978-981-15-1346-6 (eBook) https://doi.org/10.1007/978-981-15-1346-6

© The Association of Oral and Maxillofacial Surgeons of India 2021

**Open Access** This book is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this book are included in the book's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the book's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specifc statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.

The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affliations.

This Springer imprint is published by the registered company Springer Nature Singapore Pte Ltd. The registered company address is: 152 Beach Road, #21-01/04 Gateway East, Singapore 189721, Singapore

Elavenil Panneerselvam Associate Professor SRM Dental College, Ramapuram Chennai, Tamil Nadu India

Vinay V. Kumar Department of Maxillofacial Plastic Surgery Uppsala University Hospital Uppsala Sweden

Nehal Patel Director, DCKH Cleft Center K. P. Sanghvi Hospital Surat, India

## **Preface**

An important question that always comes up when a book of this scope and extent is written is: why do we need one more?

This deserves a thoughtful answer and we shall try to do that while tracing the origin and evolution of this book from an idea. Since its inception in 1969, the *Association of Oral and Maxillofacial Surgeons of India* (AOMSI) has made steady and signifcant progress in terms of its vision and commitment to promote the feld. The members of AOMSI have also evolved into a vibrant, multidimensional, passionate, and committed community of oral and maxillofacial surgeons who are making substantial contribution to the feld in India and around the world. So it was only natural that the association decided to express its commitment to academic medicine coinciding with its 50th year in existence.

And what better way to express it than publishing an open source comprehensive textbook on oral and maxillofacial surgery. This book showcases the experts and expertise of AOMSI and has been made freely available to surgeons worldwide through generous funding from the association. We are delighted to see this open access book published for free use by worldwide community of MaxFac surgeons, especially the young surgeons and trainees in the feld. This book is published with a CCBY license and we encourage associations and institutes to widely distribute the link to this book for maximum possible usage.

The AOMSI was very conscious that the development of our speciality was not an insular one. As we evolved, we looked for guidance and training from colleagues around the world, and in return, we provided our bit of experience and insights. This exchange of knowledge is extremely important for ultimately improving patient treatment methods, techniques, and outcomes. The same spirit was applied in producing this book as well' as we requested eminent clinicians and researchers from around the world along with our members to contribute to this book.

The book has contributions by society's members within India as well as 41 international authors from various countries. Thus, the extent of this makes it one of the most comprehensive textbooks on the topic. The contributors were invited by the AOMSI keeping in mind their scholastic profle while ensuring diversity and inclusiveness as well as a mix of young and experienced surgeons. All the contributors have a track record of being high-volume clinicians and educators in their feld of expertise and are generally working at prestigious teaching institutions. This textbook as a scholarly venture condenses and amalgamates both the authors' personal experience as well as being in line with the current evidence-based treatment principles in the feld of maxillofacial surgery. In the beginning, the heterogeneous source of knowledge did pose editorial challenges in standardization of the chapter structuring and scope. However, the fnal outcome has achieved a blend of evidence-based, diverse surgical practices along with cutting-edge technology for the practice of maxillofacial surgery in a fairly uniform format.

As the title suggests, this is meant to be a comprehensive resource for all clinicians, postgraduate trainees, and young surgeons in their day-to-day clinical work. Graduate students and surgeons will fnd this book useful in preparing for their university exams as well as boardcertifed exams from professional organizations. The book will help in decision-making, implementing treatment plans, and managing problems that may arise while executing these plans. Overall, the key objective is to help crystallize current evidence and provide protocols, guidelines, and recommendations to assist dealing with most clinical scenarios. Keeping this objective in mind, we have included components like case scenarios and video recordings of surgical procedures in the book.

*Oral and Maxillofacial Surgery for the Clinician* is a compilation of 22 sections incorporating 88 chapters dealing with the nuances in the principles and practice of cranio-maxillofacial and head and neck surgery. An important value addition is the library of 68 demonstrational videos that have been compiled to give the readers a more interactive feel with audiovisual inputs.

The book is structured in a step-ladder fashion to guide the reader through the basic principles of surgery before exposing to the full spectrum of specialty cranio-maxillofacial work. The frst section is devoted to the origin and scope of oral and maxillofacial surgery as a specialty and a description of the training standards practiced globally. The next four sections are tailored to discuss the prospective patient, investigations, patient preparation, and anesthesia techniques. Subsequent sections focus on minor surgical procedures involving the practice of dento-alveolar surgery, implantology, and orofacial infections. With the above as the basis, the textbook progresses to complex surgical procedures including facial trauma, orthognathic surgery, TMJ, surgical pathology, and craniofacial and reconstructive surgery. The book also features two exclusive sections which provide the readers a perspective on practice management and research and publication.

The editors of the book would like to thank the offce bearers of the AOMSI, in particular, the dynamic and effervescent secretary, Pritham Shetty, for the constant support he gave while undertaking this project.

Brishank Pratap, our tireless and innovative illustrator, needs a special mention for his superb rendition of medical and technical illustrations throughout this book.

Our publisher Springer, particularly, Naren Aggarwal and Jagjeet Kaur, deserves our gratitude for constant support and advice throughout the preparation of this book.

Last but not least, we would like to express our deep appreciation for the authors for their time, efforts, and priceless contributions.

We hope this book will be read worldwide, and we look forward to hear its critical reviews.

Bangalore, India Krishnamurthy Bonanthaya Chennai, India Elavenil Panneerselvam Trivandrum, India Suvy Manuel Uppsala, Sweden Vinay V. Kumar Bhopal, India Anshul Rai Chennai, India Jimson Samson Surat, India Nehal Patel

## **Contents**

#### **Part I Introduction**






x


xi

Sunil Richardson and Rakshit Vijay Sinai Khandeparker


Srinivasa R. Chandra and Vijay Pillai

## **List of Videos**


## **Chapter Contributors and Video Contributors**

#### **Contributors**

**Avni Pandey Acharya** GSR Institute of Cranio-maxillofacial & Facial Plastic Surgery, Hyderabad, Telangana, India

**H. S. Adenwalla** Department of Plastic Surgery, Burns and the Charles Pinto Centre for Cleft Lip, Palate and Craniofacial Anomalies, Jubilee Mission Medical College and Research Institute, Thrissur, Kerala, India

**Neha Aggarwal** Nair Hospital Dental College, Mumbai, Maharashtra, India

Meenakshi Cleft and Craniofacial Centre, Chennai, Tamil Nadu, India

**Nisheet Anant Agni** Department of Oral and Maxillofacial Surgery, SMBT Institute of Dental Sciences and Research, Nashik, India

**Suman Ananathanarayana** Department of Anesthesiology, Columbia Asia Referral Hospital, Yeshwantpur, Bangalore, Karnataka, India

**Sonal Anchlia** Department of Oral & Maxillofacial Surgery, Government Dental College & Hospital, Ahmedabad, Gujarat, India

**Neelam N. Andrade** Department of Oral and Maxillofacial Surgery, Nair Hospital Dental College, Mumbai, Maharashtra, India

**Yashoda Ashok** Department of Oral and Maxillofacial Surgery, Meenakshi Ammal Dental College and Hospitals, Chennai, Tamil Nadu, India

**Prithvi S. Bachalli** Department of Oral and Maxillofacial Surgery, Rangadore Memorial Hospital, Apollo Hospitals, Bangalore, Karnataka, India

**Mirza Farhatullah Baig** Department of Oral and Maxillofacial Surgery, Saveetha Dental College, Chennai, Tamil Nadu, India

**Kannan Balaraman** Department of Oral and Maxillofacial Surgery, Ganga Medical Centre and Hospitals, Coimbatore, Tamil Nadu, India

**Rishi Kumar Bali** Postgraduate Department of OMFS, DAV Dental College Hospital, Yamunanagar, Haryana, India

**Peter A. Brennan** Maxillofacial Unit, Queen Alexandria Hospital, Portsmouth, UK

**Srinivasa R. Chandra** Department of Head and Neck Oncology and Reconstructive Microvascular and Oral and Maxillofacial Surgery, Fred and Pamela Buffett Cancer Center, UNMC, Omaha, NE, USA

**Jaideep Singh Chauhan** Department of Maxillofacial Surgery, the Smile Train CHL Hospital, Indore, Madhya Pradesh, India

**Aarti Chowdhary** Department of Periodontology, SD Dental College and Hospital, Parbhani, Maharashtra, India

**John Collin** Department of Oral and Maxillofacial Surgery, University of Florida, Jacksonville, FL, USA

**Ashok Dabir** D. Y. Patil University School of Dentistry, Nerul, Navi Mumbai, India Breach Candy Hospital, Mumbai, India

**Abhay Datarkar** Department of Oral and Maxillofacial Surgery, Government Dental College and Hospital, Medical College Premises, Nagpur, Maharashtra, India

**Vijay Deshmukh** Deshmukh Institute of Maxillofacial Surgery and Research Centre, Aurangabad, Maharashtra, India

JIIU'S Indian Institute of Medical Sciences, Jalna, Maharashtra, India

**Amit Dhawan** Department of Oral and Maxillofacial Surgery, SGRD Dental Institute, Amritsar, India

**George Dimitroulis** Maxillofacial Unit, St. Vincent's Hospital—University of Melbourne, Melbourne, Australia

**Vikas Dhupar** Department of Oral and Maxillofacial Surgery, Goa Dental College and Hospital, Bambolim, Goa, India

**Supriya Ebenezer** Department of Oral Surgery and Stomatology, University of Bern, Bern, Switzerland

**El Mustafa** Department of Oral and Maxillofacial Surgery, Queen Elizabeth Hospital, Birmingham, UK

**Madan G. Ethunandan** Consultant Oral and Maxillofacial/Skull Base Surgeon, Honorary Senior Clinical Lecturer, Lead, Head and Neck Cancer, University Hospital Southampton, Southampton, UK

**Carlo Ferretti** , Johannesburg, South Africa

Department of Maxillofacial and Oral Surgery, University of Pretoria, Pretoria, South Africa

**Rui Fernandes** Department of Oral and Maxillofacial Surgery, Head and Neck Oncologic Surgery and Microvascular Fellowship, University of Florida, Jacksonville, FL, USA

**Rajasekhar Gaddipati** Department of Oral and Maxillofacial Surgery, Mamata Dental College, Khammam, Telangana, India

**Divya P. Gadre** Gadre Clinic, Pune, Maharashtra, India

**Kiran S. Gadre** Gadre Clinic, Pune, Maharashtra, India

Department of Oral and Maxillofacial Surgery, Bharati Vidyapeeth Dental College and Hospital, Pune, Maharashtra, India

**Raja Sekhar Gali** Department of Oral and Maxillofacial Surgery, Narayana Dental College and Hospital, Nellore, Andhra Pradesh, India

Medicover Hospital, Nellore, Andhra Pradesh, India

**Kandasamy Ganesan** Department of Oral and Maxillofacial Surgery, Southend University Hospitals NHS Trust, Southend-on-Sea, UK University of Leeds, Leeds, UK

**Jaime Grant** Birmingham Children's Hospital, Birmingham, UK

**Beat Hammer** CFC Hirslanden Kopf Zentrum, Aarau, Switzerland

**Kalarikkal Mukundan Harish** Department of Oral & Maxillofacial Surgery, Ragas Dental College, Chennai, Tamil Nadu, India

**Velupillai Ilankovan** Oral and Maxillofacial Surgery, Poole Hospital NHS Foundation Trust, Poole, UK

**D' Souza Jacob** Maxillofacial Unit, Royal Surrey County Hospital, Guilford, UK

**Oommen Aju Jacob** Department of Oral and Maxillofacial Surgery, Ananthapuri Hospitals and Research Institute, Trivandrum, Kerala, India

Kerala Institute of Medical Sciences, Trivandrum, Kerala, India

**Rebecca Jacob** Department of Anesthesiology, Columbia Asia Referral Hospital, Yeshwantpur, Bangalore, Karnataka, India

**Anuj Jain** Oral and Maxillofacial Surgeon, Department of Trauma and Emergency Medicine, All India Institute of Medical Sciences, Bhopal, Madhya Pradesh, India

**B. S. Jayanth** Oral and Maxillofacial Surgeon, ABMSS, Bengaluru, Karnataka, India

**Samson Jimson** Department of Oral and Maxillofacial Surgery, Tagore Dental College and Hospital, Chennai, Tamil Nadu, India

**Bobby John** Department of Oral and Maxillofacial Surgery, Government Dental College, Kottayam, Kerala, India

Kerala University of Health Sciences, Thrissur, Kerala, India

**Reena Rachel John** Department of Oral and Maxillofacial Surgery, Vinayaka Mission's Sankarachariar Dental College and Hospital, VMRF, DU, Salem, India

**Maj Anson Jose** Oral and Maxillofacial Surgery, ADC R&R, New Delhi, India

**Shyamsundar K. Joshi** Department of Radiology, SDM College of Medical Sciences and Hospital, Shri Dharmasthala Manjunatheshwara University, Dharwad, India

**Takahiro Kanno** Department of Oral and Maxillofacial Surgery, Shimane University, Faculty of Medicine, Izumo, Shimane, Japan

**Taranjit Kaur** Department of Oral and Maxillofacial Surgery, Government Dental College and Hospital, Jamnagar, Gujarat, India

**Manal M. Khan** Department of Burns and Plastic Surgery, AIIMS Bhopal, Bhopal, Madhya Pradesh, India

**Rakshit Vijay Sinai Khandeparker** Department of Oral and Maxillofacial Surgery, Goa Dental College and Hospital, Bambolim, Goa, India

**Annie I. Kochuveettil** Department of Radiology, SDM College of Medical Sciences and Hospital, Shri Dharmasthala Manjunatheshwara University, Dharwad, India

**David Koppel** Scottish National Craniofacial Service for Children and Young People, Royal Hospital for Children, Glasgow, UK

**Shreya Krishna** Oral and Maxillofacial Surgery, Rangadore Memorial Hospital, Apollo Hospitals, Bangalore, India

**V. B. Krishnakumar Raja** Department of Oral & Maxillofacial Surgery, SRM Dental College & Hospital, Ramapuram, Chennai, Tamil Nadu, India

**B. Krishnan** Department of Dentistry, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India

**Deepak G. Krishnan** Oral and Maxillofacial Surgery, University of Cincinnati Medical Center, Cincinnati, OH, USA

Cincinnati Children's Hospital and Medical Center, Cincinnati, OH, USA

**Balasubramanya Kumar** Department of Oral and Maxillofacial Surgery, St. Marthas's Hospital, Bangalore, Karnataka, India

Bhagwan Mahaveer Jain Hospital, Vikram Hospital, Bangalore, Karnataka, India

**Vinay V. Kumar** Department of Maxillofacial and Plastic Surgery, Uppsala University Hospital, Uppsala, Sweden

**Moni Abraham Kuriakose** Cochin Cancer Research Centre, Kochi, Kerala, India

**Paritkumar Ladani** Swiss Cleft and Craniofacial Centre, BSES MG Hospital, Mumbai, India

**Subramanyam S. Mahankali** Department of Anesthesiology, Columbia Asia Referral Hospital, Yeshwantpur, Bangalore, Karnataka, India

**Neelima Malik** Department of Oral and Maxillofacial Surgery, Krishna Institute of Medical Sciences "Deemed to be University", Karad, Maharashtra, India

**Varghese Mani** Department of Oral and Maxillofacial Surgery, Mar Baselios Dental College, Kothamangalam, Kerala, India

**Suvy Manuel** Department of Oral and Maxillofacial Surgery, Ananthapuri Hospitals and Research Institute, Trivandrum, Kerala, India

Kerala Institute of Medical Sciences, Trivandrum, Kerala, India

**Renita Maria** Department of Anesthesiology, Columbia Asia Referral Hospital, Yeshwantpur, Bangalore, Karnataka, India

**Madhulaxmi Marimuthu** Department of Oral & Maxillofacial Surgery, Saveetha Dental College & Hospital, Chennai, Tamil Nadu, India

**Paul Mathai** Nair Hospital Dental College, Mumbai, Maharashtra, India

Department of Oral and Maxillofacial Surgery, Jubilee Mission Medical College & Research Institute, Thrissur, Kerala, India

**Philip Mathew** Department of Oral and Maxillofacial Surgery, Jubilee Mission Medical College & Research Institute, Thrissur, Kerala, India

**Sainath Matsa** Praseedha Clinic for Maxillofacial Cosmetic Surgery, Chennai, Tamil Nadu, India

**Divya Mehrotra** Department of Oral and Maxillofacial Surgery, King George's Medical University, Lucknow, India

**Sushma Mehta** Mazumdar Shaw Cancer Center, Bengaluru, Karnataka, India

**Suresh Menon** Department of Oral and Maxillofacial Surgery, Vydehi Institute of Dental Sciences and Research Centre, Bangalore, Karnataka, India

**Aditya Moorthy** Department of Oral and Maxillofacial Surgery, Rangadore Memorial Hospital, Apollo Hospitals, Bangalore, Karnataka, India

**Mustafa. K** Department of Craniofacial Surgery, Kanachur Institute of Medical Sciences, Mangalore, Karnataka, India

**Veerabahu Muthusubramanian** Department of Oral & Maxillofacial Surgery, Ragas Dental College, Chennai, Tamil Nadu, India

**Sowjanya Nagamalla** Department of Oral and Maxillofacial Surgery, Virginia Commonwealth University Medical Center, Richmond, VA, USA

**Sanjiv Nair** Department of Oral and Maxillofacial Surgery, Bhagwan Mahaveer Jain Hospital, Bengaluru, Karnataka, India

**P. V. Narayanan** Consultant Plastic Surgeon, Jubilee Mission Medical College & Research Institute, Thrissur, Kerala, India

**Nasir A. Nasser** Barts & London NHS Trust, Whipps Cross University Hospital, London, UK University Hospital, Berne, Switzerland

**J. Naveen Kumar** Oral and Maxillofacial Surgery, Sri Ramachandra Institute of Higher Education and Research, Chennai, India

**Kishore Nayak** Bhagvan Jain Mahaveer Hospital, Bangalore, India

**R. S. Neelakandan** Department of Oral and Maxillofacial Surgery, Meenakshi Ammal Dental College and Hospital, MAHER, Chennai, Tamil Nadu, India

**Rachel S. Oeppen** Consultant Radiologist, University Hospital Southampton, Southampton, UK

**Arun Kumar Panda** Department of Oral & Maxillofacial Surgery, SD Dental College and Hospital, Parbhani, Maharashtra, India

**Elavenil Panneerselvam** Department of Oral and Maxillofacial Surgery, SRM Dental College, Ramapuram, Chennai, Tamil Nadu, India

Department of Orbit & Oculoplasty, Aravind Eye Hospital, Chennai, Tamil Nadu, India

**Shreya Panwar** Department of Oral & Maxillofacial Surgery, Meenakshi Ammal Dental College & Hospital, Chennai, Tamil Nadu, India

**Ananthanarayanan Parameswaran** Department of Oral and Maxillofacial Surgery, Meenakshiammal Dental College & Hospital, Chennai, Tamil Nadu, India

Department of Orbit, Oculoplasty, Reconstructive & Aesthetic Surgery, Shankara Nethralaya, Chennai, Tamil Nadu, India

Department of Orbit & Oculoplasty, Aravind Eye Hospital, Chennai, Tamil Nadu, India

**Satyen Parida** Department of Anesthesiology and Critical Care, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India

**Sat Parmar** Department of Oral and Maxillofacial Surgery, Queen Elizabeth Hospital, Birmingham, UK

**Mamatha Patil** Department of Oral and Maxillofacial Surgery, Sparsh Hospital, Bangalore, Karnataka, India

**George Paul** Kerala University of Health Sciences, Thrissur, Kerala, India

Dr MGR Medical University, Chennai, Tamil Nadu, India

**Vijay Pillai** Department of Head and Neck Surgical Oncology, Mazumdar Shaw Cancer Center, Narayana Health, Bangalore, Karnataka, India

**Sreedhar Reddy Pothula** Oral and Maxillofacial Surgery, Pioneer advanced Hair Transplant Centre, Bengaluru, Karnataka, India

**Abhinand Potturi** SVS Institute of Dental Sciences, Mahabubnagar, Telangana State, India

**Akhilesh Prathap** Department of Oral and Maxillofacial Surgery, Pushpagiri College of Dental Sciences, Thiruvalla, Kerala, India

**Prav Praveen** Department of Oral and Maxillofacial Surgery, Queen Elizabeth Hospital, Birmingham NHS Foundation Trust, Birmingham, UK

**Boyapati Raghu** Maxillofacial Unit, Royal Surrey County Hospital, Guilford, UK

**Anshul Rai** Department of Dentistry, All India Institute of Medical Sciences, Bhopal, Madhya Pradesh, India

**Manjunath Rai** Department of OMFS, A. J. Institute of Dental Sciences, Mangalore, Karnataka, India

Faculty of Dentistry, RGUHS, Bangalore, India

**Manikandhan Ramanathan** Department of Oral and Maxillofacial surgery, Meenakshi Ammal Dental College and Hospital, MAHER University, Chennai, Tamil Nadu, India Meenakshi Cleft and Craniofacial Centre, Chennai, Tamil Nadu, India

**Dipesh Rao** Bhagwan Mahaveer Jain Hospital, Bangalore, Karnataka, India

**Latha P. Rao** Department of Craniomaxillofacial Surgery, Aster Medcity, Kochi, Kerala, India

**Neelam Rathod** Department of Oral and Maxillofacial Surgery, Southend University Hospitals NHS trust, Southend-on-Sea, UK

**Poornima Ravi** Department of Oral and Maxillofacial Surgery, SRM Dental College, Ramapuram, Chennai, Tamil Nadu, India

**Srinivas Gosla Reddy** GSR Institute of Cranio-maxillofacial & Facial Plastic Surgery, Hyderabad, Telangana, India

**N. Viveka Vardhan Reddy** Oral and Maxillofacial Surgery, SVS Institute of Dental Sciences, Mahabubnagar, Telangana, India

**Shravan Renapurkar** Department of Oral and Maxillofacial Surgery, Virginia Commonwealth University Medical Center, Richmond, VA, USA

**Christoph Renné** Group Practice for Pathology Wiesbaden, Wiesbaden, Germany

**Tara Renton** Oral Surgery, Kings College, London, UK

**Johan P. Reyneke** Center for Orthognathic Surgery, Mediclinic, Cape Town, South Africa

Department of Oral and Maxillofacial Surgery, Faculty of Health Sciences, University of the Western Cape, Cape Town, South Africa

Department of Oral and Maxillofacial Surgery, University of Oklahoma, Oklahoma City, OK, USA

**Sunil Richardson** Richardson's Dental and Craniofacial Hospital, Nagercoil, Tamil Nadu, India

**Saurabh Saigal** Department of Anaesthesiology, AIIMS Bhopal, Bhopal, Madhya Pradesh, India

**B. Sasikala** Department of Oral and Maxillofacial Surgery, SRM Dental College, Ramapuram, Chennai, Tamil Nadu, India

**Anna Sayan** Poole Hospital NHS Foundation Trust, Poole, UK

**Tian Ee Seah** TES Clinic for Face and Jaw, Singapore, Singapore

**Nallamilli V. S. Sekhar Reddy** Panineeya Institute of Dental Sciences and Research Centre, Hyderabad, Telangana, India

**Anjan Kumar Shah** Department of Oral and Maxillofacial Surgery, Rajarajeswari Dental College, Bangalore, India

Bhagwan Mahaveer Jain Hospital, Bangalore, India

**Garima Sharma** Department of Anesthesiology, Columbia Asia Referral Hospital, Yeshwantpur, Bangalore, Karnataka, India

**Lt Col Rohit Sharma** Oral and Maxillofacial Surgery, 11 Corps Dental Unit, Jalandhar Cantt, India

**Kishore Shekar** Head and Neck Surgeon (OMFS), Ninewells Hospital and Dundee, University Medical School, Dundee, UK

**Pritham N. Shetty** Department of Oral and maxillofacial surgery, Bangalore Institute of Dental Science, Bangalore, Karnataka, India

**Omkar Anand Shetye** Department of Oral and Maxillofacial Surgery, Goa Dental College and Hospital, Bambolim, Goa, India

**Sunil S. Shroff** Department of Oral and Maxillofacial Surgery, Bhagwan Mahaveer Jain Hospital, Bengaluru, Karnataka, India

**Anand Shukla** Department of Oral and Maxillofacial Surgery, King George's Medical University, Lucknow, India

**Deepti Simon** Department of Oral and Maxillofacial Surgery, Government Dental College, Trivandrum, Kerala, India

Kerala University of Health Sciences, Thrissur, Kerala, India

**Robert A. Strauss** Department of Oral and Maxillofacial Surgery, Virginia Commonwealth University Medical Center, Richmond, VA, USA

**Shintaro Sukegawa** Division of Oral and Maxillofacial Surgery, Kagawa Prefectural Central Hospital, Takamatsu, Kagawa, Japan

**Shikha Tayal** Department of Oral and Maxillofacial Surgery, Government Dental College and Hospital, Medical College Premises, Nagpur, Maharashtra, India

**Mary Thomas** Department of Anesthesiology, Regional Cancer Centre, Medical College Campus, Thiruvananthapuram, Kerala, India

**Andreas Thor** Department of Maxillofacial and Plastic Surgery, Uppsala University Hospital, Uppsala, Sweden

**Asha Thomson** Norfolk and Norwich University Hospitals, Norfolk, UK

**Benjamin Turner** Department of Oral and Maxillofacial Surgery, University of Florida, Jacksonville, FL, USA

**Jayesh Vahanwala** Department of Oral and Maxillofacial Surgery, Vaidik Dental College & Research Centre, Nani Daman, India

Breach Candy Hospital, Mumbai, India

**George Varghese** Principal, Professor and Head, Department of Oral and Maxillofacial Surgery, Pushpagiri College of Dental Sciences, Tiruvalla, Kerala, India

**Ravi Veeraraghavan** Department of Oral and Maxillofacial Surgery, Amrita School of Dentistry, Ernakulam, India

**Payal Verma** Oral and Maxillofacial Surgery, University of Cincinnati Medical Center, OH, Cincinnati, USA

**Christian Walter** Oral and Maxillofacial Surgery—Plastic Surgery, Mediplus Clinic Mainz, Mainz, Germany

**Gary Warburton** Department of Oral and Maxillofacial Surgery, University of Maryland School of Dentistry, Baltimore, MD, USA

**Frank Wilde** Department of Oral and Plastic Maxillofacial Surgery, Armed Forces Hospital, Ulm, Germany

Department of Oral and Maxillofacial Surgery, University Hospital, Ulm, Germany

**Abhilasha Yadav** Department of Oral and Maxillofacial Surgery, Awadh Dental College & Hospital, Jamshedpur, Jharkhand, India

#### **Video Contributors**

**Prithvi S. Bachalli** Department of Oral and Maxillofacial Surgery, Rangadore Memorial Hospital, Apollo Hospitals, Bangalore, Karnataka, India

**Ramdas Balakrishna** Department of Oral and Maxillofacial Surgery, KLE's Institute of Dental Science and Research, Bangalore, India

**Anandh Balasubramanian** Department of Oral and Maxillofacial Surgery, Tagore Dental College and Hospital, Chennai, Tamil Nadu, India

**Mohan Baliga** Department of Oral and Maxillofacial Surgery, Manipal College of Dental Sciences, MAHE, Mangalore, Karnataka, India

**Biswajit Kumar Biswas** Avinash Institute of craniofacial and Reconstructive Surgery, Kolkata, India

**Lokesh Bhanumurthy** Department of Oral and Maxillofacial Surgery, Tagore Dental College and Hospital, Chennai, Tamil Nadu, India

**Rohit Chandra** Oral and Maxillofacial Surgeon, Department of Plastic Surgery, Max Hospitals, Vaishali and Noida, India

**Jaideep Singh Chauhan** Department of Oral and Maxillofacial Surgery, CHL Hospitals, Indore, Madhya Pradesh, India

**Anil Kumar Desai** Craniofacial Unit, SDM College of Dental Sciences & Hospital, Dharwad, India

**Anjaneya Dube** Department of Oral and Maxillofacial Surgery, Saptarshi Hospital and Cancer Centre, Jabalpur National Hospital, Jabalpur, India

**Gunjan Dube** Dube Surgical and Dental Hospital, Jabalpur, Madhya Pradesh, India

**Shehzana Fatima** Oral and Maxillofacial Surgeon, Dubai Health Authority, Dubai, UAE

**S. Girish Rao** Oral and Maxillofacial Surgeon, Shri Shankara Cancer Hospital and Research Center, Apollo Hospitals, Sagar Hospitals, Trustwell Hospital, NIMHANS, Bangalore, India

**Charu Girotra** Department of OMFS, School of Dentistry, D. Y. Patil Deemed to be University, Navi Mumbai, Maharashtra, India

**Gaurav Mahesh Gupta** Centre for Craniomaxillo Facial and Facial Plastic Surgery, Pushpanjali Hospital & Research Centre, Agra, Uttar Pradesh, India

**Rebecca Jacob** Department of Anesthesiology, Columbia Asia Referral Hospital, Yeshwantpur, Bangalore, India

**Jagadish Chandra** Department of OMFS, Yenepoya Dental College, Yenepoya Deemed to be University, Mangalore, India

**Samson Jimson** Department of Oral & Maxillofacial Surgery, Tagore Dental College & Hospital, Chennai, India

**Adarsh Kudva** Department of Oral and Maxillofacial Surgery, Manipal College of Dental Sciences, Mahe University, Manipal, India

**Deepak Kulkarni** Department of Oral and Maxillofacial Surgery, Dr D Y Patil Dental College, Pune, India

**Balasubramanya Kumar** Department of Oral and Maxillofacial Surgery, Bhagwan Mahaveer Jain Hospital, Vikram Hospital, Bangalore, India

**Paritkumar Ladani** Swiss Cleft and Craniofacial Centre, BSES MG Hospital, Mumbai, India

**Ummar Mangalath** Department of Oral and Maxillofacial Surgery, MES Dental College, Perinthalmanna, Kerala, India

**Philip Mathew** Department of Oral and Maxillofacial Surgery, Jubilee Mission Medical College and Hospital, Thrissur, Kerala, India

**Sainath Matsa** Praseedha Clinic for Maxillofacial Cosmetic Surgery, Chennai, Tamil Nadu, India

**Aditya Moorthy** Department of Oral and Maxillofacial Surgery, Rangadore Memorial Hospital, Apollo Hospitals, Bangalore, Karnataka, India

**Ravindran Nair** Department of Oral and Maxillofacial Surgery, Government Medical College, Manjeri, Kerala, India

**Anuradha Navaneetham** Department of Oral and Maxillofacial Surgery, M R Ambedkar Dental College, Rajiv Gandhi University, Bangalore, India

**Nilesh Pagaria** Oral and Maxillofacial Surgeon, Shrikrishna Hospital, Raipur, Chhattisgarh, India

**Arun Kumar Panda** Department of Oral & Maxillofacial Surgery, SD Dental College and Hospital, Parbhani, Maharashtra, India

**Ananthanarayanan Parameswaran** Department of Oral and Maxillofacial Surgery, Meenakshi Ammal Dental College & Hospital, Chennai, Tamil Nadu, India

**Nehal Patel** NuFace Maxillofacial Hospital, Surat, Gujarat, India

**Kavitha Prasad** Faculty of Dental Sciences, Ramaiah University of Applied Sciences, Bengaluru, India

**Satish Kumaran Pugazhendi** Department of Oral and Maxillofacial Surgery, M. R. Ambedkar Dental College, Bangalore, India

**Gunaseelan Rajan** Oral and Maxillofacial Surgeon, Rajan Dental Hospital, Chennai, Tamil Nadu, India

**Rajasekhar Gaddipati** Department of Oral and Maxillofacial Surgery, Mamata Dental College, Khammam, Telangana, India

**Sushmitha Rajmohan** Department of Dentistry & Maxillofacial Surgery, ESIC Model Hospital, Indore, India

Aasya the Clinic for Face Jaws & Teeth, Vijaynagar, Indore, MP, India

**Vidya Rattan** Unit of Oral & Maxillofacial Surgery, Oral Health Sciences Centre, Postgraduate Institute of Medical Education & Research, Chandigarh, India

**Pothula Sreedhar Reddy** Oral and Maxillofacial Surgeon, Pioneer Advanced Hair Transplant Center, Bangalore, India

**Sunil Richardson** Richardson's Dental and Craniofacial Hospital, Nagercoil, Tamil Nadu, India

**Senthil Murugan** Department of Oncology & Reconstructive Microsurgery, Saveetha Dental College, Saveetha University, Chennai, Tamil Nadu, India

DWIJAN Microsurgery Research & Training Centre, Chennai, India

**Navin Shah Sunderlal** Department of Oral and Maxillofacial Surgery, KM Shah Dental College, Sumandeep Vidyapeeth, A Central deemed to be University, Vadodara, Gujarat, India

**Yeshaswini Thelekkat** Department of Oral & Maxillofacial Surgery, Azeezia College of Dental Sciences and Research Kollam, Kollam, Kerala, India

**Joji Thomas** Department of Oral and Maxillofacial Surgery, Cosmopolitan Hospital Pvt Ltd, Trivandrum, Kerala, India

**P. Varun Menon** The Charles Pinto Centre for Cleft Lip, Palate and Craniofacial Anomalies, Jubilee Mission, Medical College & Research Institute, Thrissur, Kerala, India

**Sankar Vinod Vichattu** Department of OMFS, Mar Baselious Dental College, Kotamangalam, Kerala, India

**B. Vikraman** Department of Oral and Maxillofacial Surgery, Ragas Dental College & Hospital, Chennai, Tamil Nadu, India

**Gary Warburton** Department of Oral & Maxillofacial Surgery, University of Maryland Dental School, Baltimore, MD, USA

## **About the Editors**

**Krishnamurthy Bonanthaya** did his postgraduate dental studies from Mangalore University, and then he obtained his MBBS from Kasturba Medical College, Manipal. He is also a fellow of the Royal College of Surgeons of England and Royal College of Surgeons of Ireland. He is currently the project director of Smile Train Project treating cleft lip and palate deformities at Bhagwan Mahaveer Jain Hospital, Bangalore. He also holds the position of professor of oral and maxillofacial surgery, Bangalore Institute of Dental Sciences, which involves undergraduate and postgraduate training and the routine mix of maxillofacial surgical management. He is the editor in chief emeritus of the *Journal of Maxillofacial and Oral Surgery* and has numerous publications to his credit.

**Elavenil Panneerselvam** completed her postgraduation in oral and maxillofacial surgery from the Tamil Nadu Dr. M.G.R. Government Medical University, Chennai, India. She also has a master's degree in business administration, specializing in hospital management, fellowship in Aesthetic Medicine and has been awarded Fellowship in Dental Surgery by the Royal College of Physicians & Surgeons of Glasgow. She has contributed to textbooks on oral anatomy, local anesthesia, plastic surgery, and pediatric TMJ surgery. Presently, she holds a faculty position at the SRM Dental College (Ramapuram), Chennai, as associate professor in oral and axillofacial surgery. She is a recipient of the MM Cooper Memorial Research Award from the Indian Society for Anatomists and the Ginwalla Trophy from the Association of Oral & Maxillofacial Surgeons of India.

**Suvy Manuel** after his postgraduation from Government Dental College, Trivandrum, University of Kerala, in 2002, gained the Diplomate of National Board in Oral & Maxillofacial Surgery, Membership from the National Academy of Medical Sciences, New Delhi, India; and Diploma of Membership in Oral surgery, Royal College of Surgeons, Edinburgh.

During his tenure in the UK, he attained the Membership of the Faculty of Dental Surgery, Royal College of Surgeons, England. Subsequently, he attained the Fellowship in Dental Surgery, Royal College of Surgeons, Edinburgh. He is the MOMS RCSEd (Diploma of Membership in Oral Surgery) Examiner for the Royal College of Surgeons of Edinburgh in the Faculty of Dental Examiners, as appointed by the Dental Examinations Committee, RCS Edinburgh.

He is former professor and postgraduate guide at the Kerala University of Health Sciences and is a reviewer for the *Journal of Maxillofacial and Oral Surgery*.

Currently, he is attached to the maxillofacial units at Ananthapuri and KIMS Hospitals, Trivandrum, India.

**Vinay V. Kumar** completed his master's in oral and maxillofacial surgery from Nair Hospital Dental College, Mumbai, India, in 2008. He was an ITI Scholar in the Department of Maxillofacial and Plastic Surgery in Johannes Gutenberg University (JGU) Mainz, Germany, in 2010, where he went on to complete his Doctorate of Medicine in Dentistry (2013), obtain a practicing license, and served as a visiting faculty. He completed the MD and PhD program at the University of Medicine, Rostock, Germany in 2018. He is currently a Specialist Oral and Maxillofacial Surgeon in the Department of Maxillofacial and Plastic Surgery, Uppsala University Hospital, Sweden in the Department of Maxillofacial Surgery, Uppsala University, Sweden.

**Anshul Rai** is an Associate Professor in Department of Dentistry at All India Institute of Medical Sciences Bhopal, MP. He has 54 publications to his credit out of which 24 belong to prestigious international journals. He has contributed as a coauthor to *Textbook of Oral and Maxillofacial Surgery* by Dr. Borle. He is a Fellow of Indian Board of Oral and Maxillofacial Surgery (FIBOMS) and a fellow of the International Board for the Certifcation of Specialists in Oral and Maxillofacial Surgery (FIBCSOMS). He is a reviewer for *Journal of Maxillofacial and oral surgery and Indian Journal of Dental Research*.

**Jimson Samson** completed his postgraduate studies at the prestigious the Tamil Nadu Dr. M.G.R. Medical University, Chennai. Since completing his MDS, he has been in academics. He is a journal reviewer and also a section editor. He has lectured at various national and international conferences. He was also a faculty at OMFS workshops.

His special interest in research has made him Vice-Principal—Research at Tagore Dental College & Hospital, Chennai. In addition, he also heads the Department of Oral and Maxillofacial Surgery. He has published in indexed journals. He is now the Hon. State Secretary of the Association of Oral and Maxillofacial Surgeons of India, Tamil Nadu and Puducherry Branch. He is also an elected member of the Executive Committee of the National Association.

He is a member of the Board of Studies for Postgraduate Studies of Oral and Maxillofacial Surgery at the Tamil Nadu Dr. M.G.R. Medical University, Chennai.

**Nehal Patel** completed his master's in oral and maxillofacial surgery from A.B. Shetty Institute of Dental Sciences, Mangalore. He did his fellowship in Cleft and Craniofacial Surgery from Mangalore. He did his mini residency in TMJ Arthroscopy and Total Joint replacement from the USA. He worked as consultant cleft and craniofacial surgeon in BSES MG Hospital. He is currently working as Director, ABMSS CLEFT PROJECT in Surat, Gujarat.

**Part I Introduction**

Bhagwan Mahaveer Jain Hospital, Bangalore, India

K. Nayak (\*)

**1**

## **Oral and Maxillofacial Surgery in India: How Did We Get Here and Where Are We Going?**

Kishore Nayak

#### **1.1 History of Our Missions and Our Challenges**

Any discussion about the history of surgery inevitably begins with an invariable reference to *Suśruta* and his contributions to facial surgery, in particular. While the contributions of the sixth-century sage surgeon may somewhat be nebulous in a foggy poorly documented history, they are inevitably (and arguably) numerous but need not be elaborated here in any manner. What is lesser known and not often spoken about is that Suśruta considered surgery the frst and foremost branch of medicine and stated, "Surgery has the superior advantage of producing instantaneous effects by means of surgical instruments and appliances. Hence, it is the highest in value of all the medical tantras. It is eternal and a source of infnite piety, imports fame and opens the gates of Heaven to its votaries. It prolongs the duration of human existence on earth and helps men in successfully fulflling their missions and earning a decent competence in life." [1, 2]

When applied specifcally to the context of the specialty of Oral and Maxillofacial surgery (OMS) emerging in India, it raises many important questions on how we have emerged and more importantly what we see ourselves evolving into in the years to come. Perhaps all those debates that we labored along numerous times were all a part of our coming of age!

Like elsewhere in the world, in the mid-twentieth century, we were probably practitioners of dentoalveolar surgery working under very trying circumstances moving on to where we are today. The specialty in India today, is truly all encompassing in its scope. It embraces the entire and extended spectrum of the practice of oral and maxillofacial surgery, and as the Association of Oral and Maxillofacial Surgeons of India (AOMSI) approaches its 50th year in 2019, there is no better time to look back and refect on the past and contemplate where we are heading. The changes that we have witnessed have been rapid and hopefully progressive. From being oral surgeons, we transitioned and added maxillofacial surgery and to our quiver and perhaps to the chagrin competing specialties treaded into areas, once considered "gray" and broadened the scope of our practices.

Mino S Ginwalla is regarded as the pioneer of oral and maxillofacial surgery in India. In the 1950s, Dr. Ginwalla arrived in Mumbai following surgical training in Montreal, Canada, and set up his practice at Nair Hospital. He was a part of the founding group of surgeons of the AOMSI in 1969. By the mid-70s, training programs were established in most of the major dental colleges throughout India. Today, there are numerous OMS training programs in India.

The dental qualifed persons are governed by the statutes of the Dental Council of India [3]. Currently, the Dental Council of India provides for a comprehensive 3-year program that includes a syllabus and curriculum that exposes trainees to standard procedures covering the full spectrum of oral and maxillofacial surgery [4]. This provides a legal framework for the OMS to function. This qualifcation itself is only permission to practice the specialty. In today's system, competence and eventual ownership of key surgical domains often only come from structured post-qualifcation training.

Thus, traditionally, the specialty in India continues to be predominately a dental subspecialty that leans toward the idea of a surgical branch of dentistry. While many arguments have been made for and against the need for a medical degree to augment the specialty, it is safe to postulate that for the near future, we will remain a dental specialty for a variety of reasons. North Americans seem to have found a middle ground and of the 101 OMS training programs in the US, 55 are single-degree programs (dental degree only) and 43 are dual-degree (dental and medical) programs, and three offer both options.

Drawing comparisons to the international scenario, the specialty has always been on a pendulous path remaining undecided on the idea of whether it wants to stay a dental

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 3

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_1

specialty or whether it wants to incorporate the medical degree. In the USA where this trend initially started, the practice of the specialty is protected by national, regional, and local legislature as a dental specialty. In reality, there is no perceivable practical difference in the scope of practice between single- or double-degree practitioners in the States. In the UK and many parts of Europe, the specialty has taken leaps and bounds toward the medical path of training and it could very well be only a matter of time before the Specialty remains only remotely associated with Dentistry. The primary challenge was a lack of understanding, which centered on the debate of whether a medical as well as a dental qualifcation was required prior to surgical training [5].

Oral and maxillofacial surgery remains a specialty of dentistry in India and most training programs involve a graduate study and thesis to obtain the Masters in Dental Surgery (MDS) degree. The dental practice act allows all qualifed dentally trained oral and maxillofacial surgeons to practice the unrestricted and full scope of the specialty, similar to what occurs in the European nations that require a medical degree. In most of Europe, OMS has become a medical subspecialty.

Public perception of the scope of practice of the specialty remains below par. The specialty gets confused with other surgical domains within both dentistry and medicine that we share a scope.

#### **1.2 Expertise, Familiarity, and Competence**

"Innovation is the combination of different ideas and contribution of the different minds."

Laskin [6] attempts to address this problem by dividing the scope of oral and maxillofacial surgery into three parts: areas of expertise, competence, and familiarity.


Laskin's system of classifcation, while seemingly appearing comprehensive, opens itself to a lot of debate and question. While there is no doubt that the areas of "expertise" are unique to our specialty, it is our foray into those areas of competence and familiarity that has led to the expansion of the scope of our specialty. This expansion and contraction of our scope may also be fundamental to continual evolution. A large majority of our colleagues in India and worldwide operate within the boundaries of that scope of practice defned as "expertise." However, to turn areas of familiarity into competence and expertise will require that the training units and staff have the required skills and volume of cases to ensure hands-on experience and documentation. Only under these circumstances can we be assured that the skill sets and competencies will be transferred and become enduring.

It is ideal that all trainees are trained to achieve competence in craniomaxillofacial trauma, orthognathic surgery, and TMJ surgery (i.e., maxillofacial surgery). This and only this can provide the transition from Oral to Maxillofacial surgery. There, however, is a clear and present reality that not all training programs are equipped to achieve this goal. Even though training standards and syllabi exist, these standards are so broad that even programs with a very limited scope of training will meet accreditation standards by reporting a narrow set of hospital-based procedures that are not representative of the scope of practice required of modern OMS. Further, the interest of the trainee in training in the full scope of surgery is a factor that leads to mediocre training. The system of choosing a postgraduate training in OMS in India is severely handicapped and primitive. The factors that decide a trainee's choice of an advanced training program have nothing to do with their aptitude or interest in a specialty. It is purely based on their standing in a national entrance examination or their affordability of a position in a private institution. This leads to complete neglect of the student's natural aptitudes leading to prosthodontists becoming orthodontists and endodontists doomed into the world of oral and maxillofacial surgery. A disinterested trainee will be barely motivated to improve the scope of their practice following completion of their training, often limiting their practice to general dentistry and minimal indulgence in areas of "expertise."

Bell [7], when contemplating the future of education and training in the specialty, raises some very valid concerns, which seem to refect the issues that affect the specialty and its future worldwide. Many reasons for the training disparities exist today—including training program location, the presence or absence of a trauma center, limited head and neck surgery experience, and local politics—but regardless, the goal should be the same: to train oral and maxillofacial surgeons to competence in the core areas of the specialty that they will eventually practice.

The key point is that we, as a specialty, should ensure that we train to competence and expertise based on geographic location, years in practice, fellowship training, and academic involvement. In years past, if an OMS graduate wished to obtain training in any areas beyond basics, then he or she often sought it outside of the specialty, in either otolaryngology or plastic surgery. With the emergence of several teaching hospitals and colleges as well as standalone independent centers of excellence, this scenario has drastically transformed in India. Further, the development of a number of fellowships that have been facilitated by the AOMSI has resulted in a robust system within the specialty that caters to the trainee's desire, merit, and quite often desire to embrace technique and technology. The rapid and natural advent of OMS into areas of oncology and reconstruction, cleft lip and palate, craniofacial surgery, and aesthetic surgery has been unprecedented and the critical mass of those who now ft in comfortably with these are their areas of expertise is on the rise.

This has been a radical transformation. A few decades ago, wandering beyond the realms of dentoalveolar surgery and facial trauma inevitably encountered a glass ceiling. Today this has been most certainly breached. Moreover, while the majority of the specialty holds itself within the original areas of expertise, there is no doubt that the Big Bang Moment for OMS in India has happened and it is a great time to contemplate where we are heading. What does the future hold for the specialty as we drift on our very own Starship Enterprise?

#### **1.3 Predicting the Future**

"Look back over the past, with its changing empires that rose and fell, and you can foresee the future, too." Marcus Aurelius.

Are we truly at a threshold or are we pieces in some continuum? What factors will drive our evolution as a specialty in India and our extended regions? What trends can we predictably follow to predict our future? Can we perhaps take a page from other felds in medicine to learn about ourselves? Will changing attitudes and aptitude of a new generation have a powerful impact on our profession or will we forever remain loyal to the vestiges of the legacy left behind for us?

Technology will undoubtedly play an important role in our future. Not just technology in patient care, but technology in our lives. Telemedicine and teleconsults will become a part of our everyday practice allowing us to practice beyond geographic limitations. Teleconferencing will make biannual AOMSI face-to-face conferences obsolete. In 2018, the American Association of Oral and Maxillofacial Surgeons (AAOMS) simulcasted their Dental Implant Conference, as did the American Society of Anesthesiologists. Their experience is that the while their total registration at these meetings went up, the number of in-person registrants did not dissipate. Consultant oral and maxillofacial surgeons all over the world have embraced telemedicine naturally, whether they realized it or not. Mobile technology allows the transfer of patient images and radiographs easily both for opinions and treatment planning. Such ease of access to patient images and documents has become a routine tool in emergency room triages of patients in the evaluation of the priority of care.

While technology in its current form is often perceived, as interruptive to one's lifestyle choices, the advent and immersion of artifcial intelligence (AI) will make today's technology ubiquitous without being intrusive. Operating theaters of the future are likely to be guarded by artifcial intelligence. Imagine an operating theater that prepares itself based on the radiofrequency identifcation (RFID) of the surgeon who swipes her/his badge at the door—that surgeon's preference cards get read by the system and a central core will prepare the instruments and supplies based on that surgeon's choices for that particular case booked for him.

Anesthesiology, radiology, and pathology are lowhanging fruits in the AI world. Radiologists in large tertiarycare centers in China, today, do not read radiographs anymore; they simply look at false positives read the previous night by their AI system. The system then learns from such mistakes and makes corrections forever. Computer systems today have the capacity of a thousand human brains to process data. The more data we feed these AI systems, the smarter they get. Google's AI product called LYNA or LymphNode Assistant is a trained algorithm that is capable of spotting the features of tumors that have metastasized, which are notoriously diffcult to detect. Self-teaching algorithm systems will likely replace monitoring duties of the anesthesiologists and critical care nurses in the hospital.

Surgical robots are also constantly evolving incorporating precision haptics and AI. Robotic arms can already perform tasks independent of a surgeon yielding it. Imperfections and errors that a surgeon may cause in an operation are avoided in robotic surgery by consistent movements, angles, and access that can only be achieved by that robot. Imagine a robotic arm that can be programed to remove a mesioangular impacted mandibular third molar? The robot surgeon can assess the angulation of the impacted tooth based on the patient's radiograph, adjust its angulation and access, make a buccal trough, and split the tooth precisely. Less error and more precision, perhaps?

The day is not far before a robotic arm can obtain a tissue sample from our patients at a mall kiosk. Algorithms can then diagnose that tissue and their radiographs distancing the patient further away from the conventional practice of medicine. What is the future of our practices and our education in these scenarios? A well-informed patient with access to information and technology may surpass the traditional medicine man for their healthcare. Direct to consumer marketing of healthcare tools such as genetic testing is already prevalent in many countries. Several patients are aware of which chemotherapy may be best effective for the management of their cancers even before they see their doctor, today. Where does that place a specialist in the future?

In a keynote address at the Royal College of Surgeons in London at the 50th anniversary of the IAOMS, Brian Schmidt DDS, MD, PhD, Director, Bluestone Center for Clinical Research, and Professor of Oral and Maxillofacial Surgery at New York University pondered about the future of OMS internationally. He emphasized three units of care that oral and maxillofacial surgeons provide universally—


His views suggested that the advent of seatbelts, airbags, and safer road conditions in most countries is diminishing our total volume of trauma. Further, patterns of wars have changed from the bayonets of World War I to dronecontrolled annihilation that ensures death! While bar fghts and interpersonal violence continue to create left-sided ZMC and mandibular fractures, the world of facial trauma is most certainly changing.

He recognized examples of how personalized medicine is infuencing the care of cancer patients. With our ability to map genomes and mutations, our ability to interpret cancer biology has had a meteoric rise even in the last decade. This leads to personalizing management via either chemotherapy or radiotherapy with predictable success making most cancers chronically manageable diseases rather than a death sentence. The future of personalized medicine will most likely put the cancer surgeon out of an occupation.

He introduced a study that demonstrated how a serendipitous fnding in mice with Treacher-Collin's syndrome treated for endometrial cancer with a chemotherapeutic agent knocked out the gene causing the craniofacial anomaly in the following generation. This suggested that we could potentially be looking at gene therapy for craniofacial anomalies, including cleft lip and palate.

Schmidt's observations and predictions suggest that the diseases and conditions that are the mainstay to our profession will alter signifcantly in the future. Laboratories in Boston are very close to creating a template stem cells construct that will replace dental implants with naturally grown teeth. A dental caries vaccine is pending worldwide use.

How will these fundamental changes alter the practice of our specialty in the future?

Super specialization within the specialty is bound to happen. Attendees of the annual sessions of the British Association of Oral and Maxillofacial Surgeons will be struck by the design of the sessions. There are sessions designed for oral surgeons, implantologists, educators, deformities surgeons, ablative surgeons, and separately for reconstructive surgeons, as there are for minimally invasive surgery, aesthetic surgeons, and lab research. Larger sister specialties like ENT-Otolaryngology have also separated themselves into subspecialties. In the US, Pediatric otolaryngology, head and neck Surgery, facial plastic surgery, otology, skull-based surgery and surgery for sleep disorders are all recognized subspecialties within ENT in the US, for which fellowship training is offered. The pediatric otolaryngologist who specializes in airway surgery is unlikely to attend a conference organized for the otologists.

Similarly, domains within oral and maxillofacial surgery are already starting to branch out into subspecialty pods and practices are being limited to the practice of such subspecialties. That focus on a specifc area within the specialty is also likely to be infuenced by reimbursement for services. The subspecialties that rake in more money for the provider will thrive quicker and heftier than the latter. Changes in reimbursement strategies by hospitals will also evolve in this equation. For instance, in the US, where a large third-party payer system exists, clinical production for a practitioner is often not measured in actual dollars, but in revenue value units (RVUs). Complex longer cases like a head and neck disease ablation and reconstruction may not be related to a large reimbursement of dollars for the surgery alone; but the fact that the operating facility was used for several hours with the utilization of other resources such as nursing care, critical care, specialists like physical therapists, speech therapists, nutritionists, and a follow-up rehabilitation facility, all add up value to the health system ensuring reimbursement.

While this model seems to be working for now, the practice of medicine in the future unfortunately will be largely devised by the market and economics. The educational debt for training our future generation is getting out of hand. In a world where access to information is undoubtedly easier, the cost of a formal education is skyrocketing. Alternate models of education may arise disrupting this traditional model. Apprenticeships of the Osler era may be aft. Centers of excellence are likely to develop that allows a pathway of nontraditional training to an interested and talented trainee. Validation agencies like the International Board of Certifcation of Oral and Maxillofacial Surgeons (IBSCOMS) will have a bigger role in providing bonafde certifcation outside of the current commercialized and often-diluted education system.

The millennial and the gen Z student will also play a large role in the evolution of the specialty. Today's trainee learns differently, synthesizes information differently. They grew up on smartphones and Google searches and not in libraries or poring over Encyclopedia Britannica. They are visual learners with a panache for hand-eye coordination. They are multitaskers. No doubt that there will exist friction between a generation of older teachers and this generation of learners. And, that too will only be momentary. The new trainee is focused on lifestyle choices and is not unabatingly focused on education and patient care. The new trainee values life outside of work just as much as work. This will bring a new kind of diversity to the workplace. To make things worse, they will be treating a generation of aging patients who are used to a different kind of doctor from their times. The average patient is older and healthier and has demands that may have been considered unreasonable at one time. They are likely to be tech-savvy themselves. They will seek many opinions before they commit to the recommendations of their provider. They are likely to choose a surgeon based on the reviews on social media and the internet. Globalization of the medical industry and technology means that they might be willing to travel to have the same procedure and product used elsewhere than their hometown hospital.

Surgeons are working longer than they ever did as well. What impact does that have in a crowded marketplace? Will aging populations of patients and surgeons see an impact on the way we work? Will longevity and increased career years keep the younger ambitious surgeon from getting to the top? The retirement age of surgeons differs all over the world. Surgery is mentally and physically demanding. What effects does that chronic stress have on both the cognitive and physical decline in surgeons? Bhatt et al. did a narrative review on the topics of "ageing" and "surgeon" in Medline in 2016 [8]. They could not fnd any common ground in these studies. A surgeon who has to hang up his knife at 40 because of severe carpal tunnel in his hands is very different from one that has excellent physical health but severe cognitive decline. The variables were too many for them to consider any consensus on their research question—"when should surgeons retire?" They concluded that," Competence should be assessed at an individual level, focusing on functional ability over chronological age; this should inform retirement policies for surgeons."

OMS is like no other branch of medicine or dentistry. It has innovated, expanded, and usurped. It has replicated the old kingdoms, which created vast expanses as it rolled along. Eventually though, experience tells us that it can collapse under its own weight and might. As we look into the future, we must not ignore our past. Empires end for two reasons… problems from within and failure to protect their borders. As for empires, so for OMS. Our mistakes and pettiness must be acknowledged, accounted for, and learned so as not to repeat them.

We might have the ability as a specialty to control most of our destiny, but some of it may be adapted based on our environments. At the end of it all, if the specialty takes heed of three fundamental principles—patient care, education, and meaningful research, we will continue to justify our existence in the future.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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**Part II**

**Preoperative Assessment and Patient Preparation/Optimization**

**2**

## **Preoperative Evaluation and Investigations for Maxillofacial Surgery**

B. Krishnan and Satyen Parida

#### **2.1 Introduction**

A meticulous preoperative evaluation with the intention of identifying modifable clinical conditions and understanding the risk stratifcation is imperative for all patients being subjected to any invasive procedure, inclusive of oral and maxillofacial surgery. Preoperative evaluation of such patients would of course differ, often dictated by age and the overall health condition that they present with. The choice of anesthesia may vary depending on the surgical procedure intended: general anesthesia, conscious sedation, regional blocks, local anesthesia, or various combinations of all of these. The current chapter focuses on the preoperative evaluation of patients posted for maxillofacial surgery under a general anesthetic in a formal operating room setting. Nevertheless, it is essential to realize that a preoperative evaluation is more or less standardized, irrespective of the type of surgery and practice (offce-based dentoalveolar surgery, trauma, orthognathic surgery, elective esthetic surgery, craniofacial surgery, etc.) and anesthesia being planned. The goals of preoperative evaluation are summarized in Fig. 2.1 [1]. The intention is to minimize perioperative morbidity and mortality, to the best possible extent. The major step toward this goal requires the surgeon to be conscientiously aware of the general condition and clinical state of the patient so that in the eventuality of a critical event, he can intervene effectively and pertinently. This would involve modifying and customization of the patient's overall management to ensure that perioperative adverse events are avoided.

S. Parida

Department of Anesthesiology and Critical Care,

#### **2.2 Preoperative Evaluation**

The process of preoperative evaluation often begins with a standard history-taking and physical examination for the particular patient. A detailed history of prior medical problems, any previous surgical procedures, family, personal, and social history, any chronic medications and allergies or addictions needs to be obtained. In addition, it is worthwhile obtaining details about the patient's family physician if any, whether he has health insurance, the employer's details if the patient is employed, contact details of relatives, and any other information that may be deemed appropriate. The maxillofacial surgeon has to judge how the medical problems of the patient will affect perioperative care, and conversely, how perioperative events would infuence the management of the patient's medical conditions. The patient's comorbidities could result in a signifcant physiologic decompensation due to myriad factors such as stress of the surgical procedure, original goals of the surgical intervention not being adequately met, and potential interactions between the regular medications that a patient may be on or with drugs that may be required to be instituted as part of the perioperative protocol. The maxillofacial surgeon should, therefore, be cognizant of what could possibly go wrong, and how those situations could be remedied. Also, it is critical that the surgeon be aware of all the medications (antidiabetic drugs, anticoagulants, antiplatelets, etc.) and medical comorbidities (cardiopulmonary, central nervous system, hepatic and renal disease, etc.) that the patient may be exposed to that could threaten the safe performance of the surgical procedure and have an adverse impact during the postoperative period. It is essential that every member of the perioperative team must be able to perform an independent assessment of the patient. This does not imply being ignorant of the other person's assessment since information needs to be shared by all components of the team, but each member should have his own way of assimilating such information by adding to it by his own independent assessment. This is important because

B. Krishnan (\*)

Department of Dentistry, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India

Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 11

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_2

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 2.1** Goals of preoperative evaluation

every specialty would have its independent perspective, about the patient, although they would all be in the latter's best interests. For example, the surgeon might look upon older age in terms of postoperative functional recovery, while the anesthesiologist would be contemplating the various comorbidities that could be associated. Accordingly, each specialist would have his own concerns regarding the state of the patient, and therefore, the preoperative assessment provides a meeting ground for all these concerns after everyone has performed his own independent assessment. The use of a medical history questionnaire provides the maxillofacial surgeon with valuable information about the physical and psychological condition of the patient. Any medical history questionnaire can either be extremely useful or totally worthless and its ultimate value depends upon the ability of the surgeon to interpret the signifcance of the answers and to elicit additional information through physical examination and dialogue history. A prototype of a health history questionnaire is seen in Table 2.1 [2].

A preoperative physical examination begins with a recording of the patient's vital signs. The oral and maxillofacial system, by virtue, of the proposed surgical site, receives close attention by the surgeon. Of particular interest for the surgeon would be recognizing potential diffculties in surgical access and the need for alternative strategies and additional surgeries (e.g., bone grafting/skin grating). The cardiopulmonary examination assesses the rate and rhythm, murmurs, wheezing, rhonchi, and stridor. The musculoskeletal examination will include a range of neck motion and

#### **Table 2.1** Preoperative medical evaluation questions for a healthy patient

#### Questions


potential donor site evaluation. Finally, a neurological examination would assess the patient's mental status and any signs of pre-existing nerve or head injuries. A detailed description of the examination of all systems is beyond the scope of this chapter and the reader is advised to consult the references at the end of this chapter [1, 3–5].

Once the history and physical examination are complete, the clinician would be in a situation to risk stratifying the patient according to the American Society of Anesthesiologists' (ASA) classifcation system (please see chapter on Ambulatory anesthesia for ASA table). Further investigations or specialist consultation is determined by the ASA status. This is especially imperative in patients with ASA Class III or IV who need to be further evaluated for their ability to withstand the proposed surgical procedure. Such patients, almost always, require inpatient admission due to a higher risk of perioperative adverse events. Patients of ASA Class V are extremely moribund and would therefore invariably require admission irrespective of the surgical procedure involved. It is extremely uncommon for a patient in this category to undergo any maxillofacial surgical procedure.

Preoperative risk stratifcation can also include a surgical classifcation system [6] (Table 2.2). This classifcation is quite useful for healthy patients undergoing a surgical procedure, as risk assessment in these patients is now determined solely by the nature of the procedure rather than the ASA


**Table 2.2** Cardiac Risk Stratifcation for Noncardiac Surgical procedures

classifcation [7]. A similar surgical severity classifcation for oral and maxillofacial procedures has also been offered [8].

The preoperative assessment for oral and maxillofacial surgery will also require appropriate radiologic imaging for diagnostic information and treatment planning. These include panoramic, periapical, and occlusal radiographs, ultrasound, CT and MRI imaging. The clinical evaluation and imaging studies should help in the formation of a surgical plan, as to whether the surgery is going to be a simple or a complex one, what kind of instrumentation will be required for the same, or whether it would require the expertise of other surgical specialties such as Ophthalmology, ENT, and Plastic Surgery. The anesthesia team can also examine these imaging modalities to identify potential diffculties that may be encountered while intubating and securing the airway.

#### **2.3 Laboratory Investigations**

Preoperative patient assessment, ASA physical status, and severity of the proposed oral and maxillofacial surgical procedure guide the clinician to select the appropriate adjunctive studies for treatment planning. The ordering of adjunctive laboratory and radiological investigations is often determined by a complex interplay of pre-existing attitudes, practice patterns learnt during training, ease of ordering, fear of medicolegal consequences, and patient requests. When ordering a test, clinicians are attempting to discriminate between patients who have normal values and those who have abnormal ones. This is used to determine the possibility of the existence of a pathological condition that could impact the proposed surgical and anesthetic plan. The "normal" reference range for many clinical lab tests excludes the upper and lower 2.5% of results, and therefore 5% of normal individuals will obtain an "abnormal" result. While these "abnormal results" can be ignored, sometimes they are not and the result is an additional unnecessary investigation. Clinicians must be confdent that there is a clinical justifcation for the actual need for the test. Studies indicate that less than 0.25% of all "abnormal" results of preoperative tests before an elective surgery infuences the perioperative management [9]. "Routine" investigations, viz., those carried out preoperatively on all patients, and not directly related to the planned surgical procedure or the patient's physical condition, are not recommended [10, 11]. Age-based criteria are controversial as test abnormalities are common in older patients but are not as predictive of complications as information gained from a detailed history and physical examination. "Cost consciousness" and "stewardship of resources" also have to be considered by the clinician as the commonly ordered "battery of tests," though relatively inexpensive by themselves, can contribute to a signifcant proportion of healthcare expenditure as a result of the frequency with which they are ordered [12]. Beyond economics, the costs borne by patients include discomfort of needle sticks and blood loss with repeated phlebotomy, exposure to radiation, and additional unnecessary workup of spurious results. Good communication between the surgeon, medical consultant, anesthesia team, and the patient is essential when considering preoperative testing that may affect the timing of the surgery. Fit, young patients who are scheduled for outpatient surgery or low-risk surgery generally do not require any routine preoperative testing and, in the pediatric age group, a thorough clinical examination has been found to be of greater value [13, 14]. Routine urine or blood testing of the pediatric patient is not clinically warranted without a specifc indication [15]. In general, test results within the past 6 months are acceptable if the patient's history has not changed. If the patient's condition has changed in the interim, adjunctive tests within the past 2 weeks are more favored [1].

The American Association of Oral and Maxillofacial Surgeons (AAOMS) recommendations on adjunctive studies prior to oral and maxillofacial surgery include, but are not limited to, both laboratory and imaging investigations [16] (Table 2.3). Similarly, algorithms based on the ASA classifcation, surgical procedure, and age of the patient are also available to assist the clinician to choose the appropriate adjunctive preoperative tests [17, 18].

While most standard texts would lead one to believe that extensive investigations in patients who are supposedly normal on history and clinical appraisal are not instrumental in improving outcomes or economically justifed, it must be remembered that these perceptions are built upon data accumulated from the West, where regular health checkups and assessments are the norms. In contrast, in countries like India, a patient's frst visit to a hospital may be for the surgery he is being posted for. Patients may also not be aware of existing comorbidities or details of any earlier interventions. This often leaves the clinician with no other option than to do order a "battery" of the so-called routine investigations to screen out potential pathological conditions. Ultimately, the choice of what laboratory investigations a patient may be subjected to is decided by the particular operating unit. It is important that such practices be customized to the population that the hospital caters to, and must be based on reasonable risk-beneft and cost analysis.

**Table 2.3** Indications for commonly ordered preoperative laboratory tests based on specifc fndings during history and physical examination (independent of patient age, American Society of Anesthesiologists' classifcation, or surgical procedure)


#### **Table 2.3** (continued)


#### **2.4 Preanesthetic Evaluation**

The preanesthetic evaluation aims at getting a favorable outcome, from the points of view of both the surgeon and the anesthesiologist by focusing on risk stratifcation and modifcation, and by developing a plan that appropriately addresses the risk-beneft ratio from the procedure, and also explores the other options available. It involves putting together all the elements of the patient's history, physical examination, medications, allergies, laboratory studies, and certain examinations of interest to the anesthesiologist (e.g., airway). This information is assimilated, and decisions are made regarding the plan for anesthetizing the patient once the full picture emerges. This, however, is a dynamic process, and hence accommodates changes in the plan, if new information surfaces, in the best interests of the patient and surgeon. It is also important to be aware of the strengths and limitations of the set-up in which the particular surgical intervention is being undertaken. Further, the preanesthetic evaluation also attempts to allay patient anxiety regarding the procedure, takes necessary steps for risk reduction and to get informed consent. Finally, it leads to the choice of the anesthetic plan to be followed, guided by the risk factors uncovered by the medical history, which covers the entire perioperative period, inclusive of a plan as to where the patient will be cared for postoperatively, and what kind of pain relief he/she should receive after surgery.

#### **2.5 Aspects of Evaluation Unique to Anesthesia**

The perspective of each specialty also drives the way physical examination is conducted by each of them. All clinicians learn early as part of their training that relevant positive and negative points not only direct the elicitation of history but also examination. Airway examination is something that is uniquely specifc to anesthesiologists with the intention of predicting a diffcult airway, that is, one that might result in diffculty in ventilating or intubating the patient, or both. The ASA task force on the management of the diffcult airway stresses importance on the physical examination of the airway [19]. While no single method can be deemed to be foolproof in this regard, the anesthesiologist is trained to examine different aspects as well as scoring systems to be able to make the assessment of a diffcult airway [20–22]. The mnemonic **LEMON** is a helpful tool for assessing the potential for diffcult intubation [23, 24] (Fig. 2.2). The Mallampati classifcation, which relates tongue size to pharyngeal size, is a common component of a thorough airway examination [25]. The examination is performed with the patient in the sitting position, the head held in a neutral position, the mouth wide open, and the tongue protruding to the maximum. The subsequent classifcation is assigned according to the pharyngeal structures that are visible: (Fig. 2.3).


The important aspects of the airway, which can affect intubation, include the degree of mouth opening, the size of the tongue in relation to other oral structures, and the capability to align the oral, pharyngeal, and laryngeal axes in more or less one straight line, with the patient's head and neck in the sniffng position. While the Mallampati classifcation relates to soft-tissue sizes and their relationships with each other, apart from mouth opening, there are several other anatomical features that need to be considered in the evaluation of the airway (Table 2.4). Examination of systems, other than the cardiopulmonary system, is dependent upon the proposed surgical procedure and planned anesthesia, along with the clinical features of the patient. For example, a patient with a Le Fort II or III fracture may require a careful neurological and ophthalmological examination. Documentation of the fndings of history and physical examination must focus on the positive and negative fndings after integrating information from the surgeon, patient, and other sources.

#### **2.6 Assessment of the Pediatric Patient**

The objective of preoperative assessment in the apparently healthy child is to discover medical or anatomic issues, hitherto not acknowledged, that will escalate the risk of surgery and anesthesia. Special attention is warranted by virtue of specifc anatomical and physiological differences from the adult patient. Additional risk factors in pediatric patients, apart from the surgery-specifc and patient-specifc risks,



**Fig. 2.3** Mallampati Classifcation for assessment for intubation. Class I: Cmplete visualization of the soft palate. No additional diffculty. Class II: Complete visualizatin of the uvula. No additional diffculty. Class III: Visualization f only the base of the uvula. Moderate diffculty. Class IV: Soft palate is not visible at all. Severe diffculty

#### **Table 2.4** Airway compromising conditions

#### • *Congenital*

	- − Supraglottis: laryngeal edema
	- − Croup: laryngeal edema
	- − Abscess (intraoral, retropharygeal): distortion of the airway and trismus
	- − Ludwig's angina: distortion of the airway and trismus
	- − Rheumatoid arthritis: temporomandibular joint ankylosis, cricoarytenoid arthritis, deviation of laynrx, restricted mobility of cervical spine
	- − Ankylosing spondylitis: ankylosis of cervical spine, less commonly ankylosis of temporomandibular joints, lack of mobility of cervical spine
	- − Cystic hygroma, lipoma, adenoma, goiter: stenosis or distortion of the airway, fxation of larynx or adjacent tissues secondary to infltration or fbrosis from irradiation

include the clinician-related risks; an acknowledgment that superior skills are called for in managing this extremely vulnerable patient population. Children with chronic medical problems require appropriate management and prediction of possible diffculties in management, which the preoperative assessment needs to focus on. Especially for infants, enquiries about prematurity, developmental milestones, and medical background check probing for possible congenital diseases of the cardiac and respiratory systems need to be made. Congenital cardiovascular malformations are frequently associated with many facial malformations, which require a thorough preoperative assessment. Another challenge that pediatric patients present, especially for the anesthesiologist, is the pediatric airway management due to a difference in the airway anatomy vis-a-vis adults. The relatively larger soft tissues in the oropharynx, a more cephalad and anterior position of the vocal cords and the larynx, and a shorter length of the trachea are among the few differences between an adult and pediatric airway anatomy [26]. These unique variations can result in airway management issues, including diffculties in sustaining a patent airway, mask ventilation, insertion of supraglottic airway devices, and endotracheal intubation.

#### **2.7 Assessment of the Elderly Patient**

Another vulnerable population is the geriatric age group. This is because older age is associated not only with dwindling functions of almost all organ systems but also an increase in the incidence of comorbidities. Further, as life expectancy increases, clinicians are likely to encounter a substantial number of elderly people in their practice, and it is conceivable that a large proportion of these may present for surgery. It is therefore vital that clinicians dealing with patients of this age group should be able to comprehend the alterations in physiology and pathophysiology that occur with aging. A diminished cardiopulmonary reserve puts this patient population under a higher risk of perioperative adverse events. Incidence of coronary artery disease is also prevalent in the geriatric population. Further, there is an increased risk of cognitive dysfunction such as dementia, delirium, and depression, which may be exacerbated in the acute postoperative phase. Elderly patients have impaired hepatic and renal metabolism and delayed clearance of drugs in the systemic circulation, which can cause increased sensitivity to intravenous anesthetics. Also important in relation to the elderly patient are several anatomical alterations, which can affect management. Predominant among these are changes in airway anatomy, such as nasopharyngeal fragility, macroglossia, microstomia, etc. [27]. These can result in diffculty in mask ventilation and placement of supraglottic airway devices and endotracheal tube.

#### **2.8 Specialist Consultation and Work-up**

The initial evaluation of the patient then leads to subsequent work-up, including obtaining consultations from other specialties if deemed necessary, re-evaluating the need for any additional investigations, taking steps to limit perioperative risks as deemed necessary, evolving an anesthetic plan, and getting informed consent from the patient. As more and more areas of concern may develop, further testing, specialist consultation, and varied approaches to risk management strategies may become imperative. As this dynamic process of comprehensive patient assessment evolves, revision of the anesthetic plan and eliciting additional specifc terms of consent from the patient may also become inevitable.

Specialist consultations are needed when the particular condition being evaluated does not come under the purview of the training of the anesthesiologist or surgeon. Such consultations must be specifc and try to elicit whether the patient is in the best possible condition with regard to his particular comorbidity to undergo the proposed intervention, or whether the malady for which consultation is being sought, can be further optimized and at what stage of the particular ailment the patient is at. When consultations are merely sent without stating specifc objectives of such request, they might meet with a similarly nonspecifc response from the consultant that the referral is being sent to, and hence proving to be of not much help for the clarifcation sought for. Thus, referrals to other disciplines need to be very specifc, as to the expectations that the referring unit has of the evaluation and the advice that they should receive. The consultant to whom the referral goes now becomes an important component of the perioperative team. It is essential that this consultant must also appreciate his role in the assessment of the patient, and this would be possible by building support networks among disciplines. This will also save time in the perioperative period, since a few investigations that the consultant being referred to would advise, may be carried out prior to the referral itself. An example would be getting an ECG and echocardiogram done prior to referring a patient with signifcant coronary artery disease to the cardiologist. Thus, the requirement for circulation of information, among disciplines, is vital and is especially true with regard to communication between consultants. Often, communicating personally with the consultant to whom the patient is being referred to, can expedite the evaluation to a very great extent.

#### **2.9 The Process of Risk Assessment**

Following a thorough evaluation and perusal of the results of the investigations, the patient-specifc risks are evident, while the surgery-specifc risks need to be considered upon, the summation of both of which contribute to the overall risk to the patient. Technical factors such as fuid shifts, total blood loss, as well as the site of the surgical intervention, are components of the surgery-specifc factors that contribute to the total risk assessment [28]. Oral and maxillofacial surgery being classifed as head and neck surgery, would normally be considered as an intermediate risk surgery, unless undertaken as emergency or anticipated to have a risk of excessive blood loss, wherein it would be classifed as a high-risk procedure. The correlation between expected blood loss and specifc maxillofacial surgeries has been demonstrated [29]. With improving the safety of anesthesia equipment and medications, the historical dangers of anesthesia administration are quite low, and patient- and surgery-specifc risk factors almost completely determine the overall risk to the patient [30, 31].

Once the overall risk of the patient is known and calculated, the next step would be to devise a strategy for risk management.

#### **2.10 Risk Reduction Strategies**

Risk reduction blueprints must be assessed and a risk-beneft ratio evaluated in performing any elective oral or maxillofacial surgical procedure. Alternative procedures and occasionally even avoiding any intervention could be considered when the overall risks in terms of morbidity and mortality to the patient are substantial. Obviously, the most critical step in risk reduction would be to get the patient in the best physical condition to undergo an interventional procedure. To this effect, modifable risk factors should be addressed (e.g., anemia, hyperglycemia, hypertension) always ensuring that the risk-beneft ratio stays in the patient's favor. As an example, in a smoker who is to undergo an intermediate- or high-risk surgery, the obvious risk reduction strategy would be to quit smoking [32, 33].

This then allows the patient's body to reap the benefts of a simple risk reduction maneuver with the risk now decreasing to a degree that might cause a favorable impact on the morbidity and mortality otherwise expected. Appropriate medical management of the comorbidities might be successful in optimizing patients to a state where they can withstand the rigors of the surgical procedure. The particular anesthetic technique apart, there are at least fve other areas that may be targeted as part of overall risk reduction strategies, namely: (a) premedication, (b) antiaspiration prophylaxis, (c) perioperative beta-blockade, (d) postoperative nausea and vomiting (PONV) prophylaxis and (e) effective postoperative pain management.

#### **2.10.1 Premedication** [4]

An increase in heart rate is the major factor increasing myocardial oxygen demand in the perioperative period. This makes appropriate anxiolysis and management of postoperative pain absolute vital cogs in the overall care of the patient undergoing surgery since anxiety and/or pain can set off a noxious cycle of events starting with tachycardia and hypertension, which could, in turn, result in perioperative myocardial infarction, the incidence of which is highest in the frst 72 h. Benzodiazepines induce anterograde amnesia, anxiolysis with mild sedation. Opiates were previously believed to be a vital part of preemptive analgesia, but later they were found to sensitize patients to pain. Clonidine may also be considered preemptive analgesia, especially when administered epidurally. However, the entire concept of pre-emptive analgesia, or antinociceptive treatment prior to initiation of the pain stimulus that prevents the establishment of altered processing of afferent input, that amplifes postoperative pain, is currently mired in controversy. Clonidine has a cardioprotective effect and also decreases the minimum alveolar concentration (MAC). Antihistamines may be used for their sedative and antiemetic properties. However, the clinician needs to know that promethazine, the most commonly prescribed antihistaminic, now carries an FDA warning for apnea and death in children. Anticholinergics are no longer used routinely, but rather to produce an antisialagogue effect when desirable (endoscopic procedures), sedation/amnesia, or to prevent refex bradycardia.

#### **2.10.2 Fasting Guidelines**

Patients with a full stomach at the time of induction of anesthesia are perceived to be at high risk of aspiration of gastric contents into their respiratory tract, and also present diffculty with intubation if gastric contents are regurgitated at the time of airway manipulation. This may lead to acute lung injury manifested as pneumonitis, aspiration pneumonia, respiratory failure, or acute respiratory distress syndrome [34]. Following administration of a general anesthetic, patients can no longer have the ability to maintain a patent airway, respiration, or protective refexes like gagging or coughing. The driving force for inducing aspiration is the barrier pressure, which is the difference between the gastroesophageal sphincter tone that opposes aspiration and the hydrostatic pressure within the stomach. In the presence of a negative barrier pressure, the possibility of regurgitation, vomiting, and aspiration is increased. One of the ways to maintain the barrier pressure positive during the vulnerable period of anesthesia is to instruct the patient to be "nil per oral" prior to surgery, such that the gastric hydrostatic pressure is kept low. What constitutes an appropriate period of fasting before anesthesia has been the subject of substantial research over several years, and current guidelines are based both on the nature of oral intake and the age of the patient [35, 36, 37] (Table 2.5). These recommendations, however, need to be viewed as guidelines, rather than a set of inviolable instructions. The reason why these rules should not be looked upon as impregnable is because these were intended for normal patients. Individual situations may sometimes prevent these nil-per-oral guidelines from providing foolproof safety from aspiration. Conditions that inhibit gastric emptying, including diabetes, morbid obesity (body mass

**Table 2.5** Preoperative fasting recommendations for healthy patients undergoing elective surgery


index [BMI] >35), pregnancy, bowel obstruction, previous upper gastrointestinal surgery, and gastrointestinal disease such as gastric ulcer, scleroderma, etc. will all escalate the risk of aspiration and deserve as much attention that a full stomach does [38–40]. Another group of patients who are believed to be at high risk for aspiration comprises those with diffcult airways, as these patients will require more prolonged airway manipulation and thus a greater time to intubation [41]. The airway remains unprotected and unsecured for a longer time and hence these patients may beneft from prophylaxis against aspiration. The preanesthetic evaluation needs to identify this special category of patients who appear to be at higher risk of aspiration, despite adhering faithfully to standard nil per oral guidelines and premedicate them for elective surgery. A prokinetic drug and an alkalinizing agent could reduce the complications from gastric aspiration by combating the corrosive acidic nature of gastric juice, even if aspiration does occur [3].

The most widely prescribed prokinetic in this regard is the dopamine-antagonist metoclopramide (10 mg orally/IV). However, this drug has the potential to cause extrapyramidal symptoms and should be used cautiously. The other pharmacological agent that increases the pH of gastric juice and makes it less acidic is a Histamine 2 (H2) receptor blocker, viz., ranitidine (150 mg orally; 50 mg IV) or famotidine (20 mg IV). Cimetidine is no longer used due to its ability to induce hepatic enzymes and infuence the metabolism of several anesthetic agents. Usually, the prokinetic along with the H2 blocker is administered both on the night before and on the morning of the surgery. Administration of two doses each of both the medications guarantees adequate plasma levels required for an effective action. Lastly, the use of particulate antacids such as citric acid/sodium citrate (30 ml) typically within 2 h prior to the anticipated induction of anesthesia also can neutralize the gastric acid, and reduce the incidence of chemical pneumonitis even if the aspiration occurs. However, its bitter taste and propensity to induce emesis necessitates that it be administered a substantial period prior to intubation.

#### **2.10.3 Perioperative Beta-Blocker Therapy**

Organ ischemia is a result of an imbalance between the oxygen supply and demand. The heart is especially vulnerable since myocardial work and oxygen demand are very tightly coupled. However, the precise level of myocardial demand at which it outstrips the supply is unclear. Hence, a patient who is susceptible to the development of myocardial ischemia needs to be managed perioperatively in a manner that keeps the demand lowest, while at the same time maximizing supply. Pharmacological manipulation of the myocardial demand is probably effected easier than a signifcant manipulation of the supply. Physiologically, tachycardia is the most important parameter that increases myocardial demand, with increases in systemic vascular resistance being the second most important [42–44]. Patients having a signifcant cardiovascular risk need a cardiologist's opinion for an evaluation of the extent of risk and preoperative optimization [6] (Table 2.6). Obviously, modifable risk factors and reversible disorders need to be addressed and managed. The ACC recommends perioperative beta-blocker therapy for patients with two or more intermedi-

**Table 2.6** Clinical predictors of increased perioperative cardiovascular risk

*Major clinical predictors (markers of unstable coronary artery disease)*


*Intermediate clinical predictors (markers of stable coronary artery disease)*


*Mild clinical predictors (increased probability of coronary artery disease)*


*Major clinical predictors*: All elective operations should be postponed and the patients properly investigated and treated. *Intermediate clinical predictors*: Proof of well-established but controlled coronary artery disease. Further risk stratifcation and optimization in consultation with cardiologist.

*Minor clinical predictors*: Increased probability of coronary artery disease, but not of an increased perioperative risk. Further risk stratifcation and optimization in consultation with cardiologist. *Emergency procedures*: Proceed for surgery with perioperative surveillance and postoperative risk stratifcation and risk factor management.

*CABG* Coronary Artery Bypass Grafting, *PTCA* Percutaneous Transluminal Coronary Angioplasty, *LVH* Left Ventricular Hypertrophy

ate risk factors or a single major risk factor, especially if being posted for an intermediate-to-high-risk surgical procedure [6]. The evaluating physician can be requested to assess the benefts of beta-blockade in the patient scheduled for maxillofacial surgery. The commonest way of introducing betablockade is with the drug metoprolol for a target basal heart rate of 60–65 beats per minute (bpm), and to sustain the rates at no more than 85 bpm during the perioperative period. Betablockade should, however, be started well before the surgery so that ample time is available to adjust the dose to the target heart rate and address any side effects that may develop. The administration of a beta-blocker just prior to an emergency surgery is controversial as this has been observed to be associated with a greater risk of perioperative strokes [45, 46]. More research is needed to clearly identify which patient subsets might beneft most from the beta-blockade, and in whom the side effects may be substantial.

#### **2.10.4 PONV Prophylaxis** [47]

Oral and Maxillofacial surgeries are generally not considered as high risk for the incidence of postoperative nausea and vomiting (PONV) [48]. Risk factors, including female gender, previous history of PONV or motion sickness, nonsmoking status, and younger age patients, have been associated with an increased incidence and severity of PONV [49]. Therefore, the preoperative assessment should be sensitive to the presence of these indicators and must devise a plan for offering pharmacological prophylaxis to this patient population. The plan for anesthesia devised preoperatively should also take into consideration that use of volatile anesthetics, opioids, and nitrous oxide may be associated with higher PONV incidence, and thus infuence the choice of anesthetic agents used. The choices for PONV prophylaxis are between 5HT3 antagonists (ondansetron, granisetron, palonosetron, etc.), dexamethasone, subanesthetic doses of propofol, scopolamine patches, etc. [50]. Generally, a combination of agents seems to work much better than a single agent.

#### **2.10.5 Plan for Postoperative Analgesia** [51]

Regional anesthesia techniques, including peripheral nerve blocks, are excellent in terms of providing quality analgesia postoperatively, but they do have their own set of risks and may cause discomfort from the ensuing numbness. Hence, it is important that the patient is taken into confdence about the risks and benefts of this modality of pain relief, while also offering alternative approaches that could be opted for. Local anesthesia in adequate concentrations and volume is essential for a pain-free postoperative period. Contrary to earlier practices, the mixing of local anesthetic solutions to apparently harness the best pharmacological effects of both is an approach, which is currently being discouraged. In fact, a successful preoperative nerve block may also be used so as to minimize the incidence of tachycardia during the intraoperative noxious stimuli, and then repeated at the culmination of the procedure, so that the effect can extend into the postprocedure period. This option can be employed by the maxillofacial surgeon resultant to their expertise in regional nerve blocks of the orofacial region. Opioids have traditionally been the workhorse for postoperative analgesia. Intravenous patient-controlled analgesia is an attractive option for the postoperative pain control for the inpatient in whom the effects of the nerve blocks are expected to wane after a few hours. However, there is accumulating evidence that a multimodal approach to pain management works best, with the intent of reducing the side effects of opioids and improving pain scores. Enhanced recovery after surgery (ERAS) protocols to minimize postsurgery hospital stay are gaining wider acceptance, and an important part of such protocols is the inclusion of multimodal opioid-sparing pain management protocols [52].

#### **2.11 Preoperative Decision Making and Obtaining Informed Consent: The Team Concept** [53]

The preoperative plan blends the patient's requirements, the competence of the perioperative team, and the infrastructure provided by the hospital to get the particular intervention done. This, it is expected, would help achieve the favorable outcome of the intervention. Quite often, the optimization of all of these conditions may not always be possible. The onus then is upon both the patient and the operating team to take a decision on what may be the acceptable course of action. Whether to pursue the performance of a particular intervention or not is, therefore, also an integral part of the preoperative decision-making process.

The fnal element of a comprehensive preoperative assessment is the process of obtaining a valid, written, and informed consent. Obviously, this process can be initiated, only after a thorough risk estimation has been made, based on the preceding evaluation of the patient, and a tentative anesthetic and surgical plan have been evolved, including strategies for management of postoperative pain. For all practical purposes, an informed consent necessitates presentation of the fnal residual risk that the patient has, which cannot be further optimized, and its expected interaction with the proposed surgical intervention. The main players in the process of obtaining informed are obviously the surgeon, anesthesiologist, and the patient. Typically, any of them has the autonomy to reject or to suggest modifcations to the proposed sequence for the intervention. It is important to note that informed consent is a process of ensuring the patient understands the risks and benefts of the available surgical and anesthetic options. It is not merely signing a consent form. The capacity of a patient refers to the ability to make decisions about their care, and to decide whether to agree to, or refuse, an examination, investigation, or treatment. To have the capacity, a patient must be able to understand and retain information regarding the treatment, evaluate the risks and benefts of treatment, reach a decision regarding their course of treatment, and communicate their decision to the clinician [54]. A patient undergoing surgery is understandably apprehensive, and hence the process of imparting information to him while taking consent must be handled professionally, yet with the utmost sensitivity [55]. It is important that the anesthesiologist and the surgeon should have thrashed out issues relating to perioperative care and broken common ground on all aspects before involving the patient (Table 2.7).

Following discussion and concordance between the surgeon and the anesthesiologist on the course of action, the patient is taken into confdence, informed about the procedure, and his/her consent for the same, sought. The information provided to the patient includes the nature of the risk involved, the benefts, and the alternatives to the proposed plan. If the proposal or any particular element of it is unacceptable to the patient, the operating team must be ready for course correction and should be able to come up with alternatives, which would be acceptable to the patient. However, if no substitute plan can be offered, and the patient is resolute in not accepting the proposed one, there is no option than to abort the proposed surgery. Options, such as referrals to other surgical teams, with different expertise or set-ups that may address the patient's concerns better and satisfy his expectations can be considered. Consequently, acquiring informed consent is a highly interactive process, with the patient being the pivot, to whom the risk-beneft ratio is projected taking into consideration his/her wishes and needs. The Association of Oral and Maxillofacial Surgeons of India consent forms can serve as a useful template for consent taking in one's clinical practice [56].

**Table 2.7** Points of concurrence between surgeon and anesthesiologist before seeking informed consent from the patient


#### **2.12 Conclusion**

"Do not operate on a stranger" is the most important mantra to be followed by any surgeon. The preoperative evaluation of oral and maxillofacial surgery patient comprises a critical part of the perioperative period and hence requires a watchful and staged outlook to risk identifcation and management, putting in place a plan for anesthesia, surgery, and postsurgical pain management. There is no substitute for a properly performed and detailed history and physical examination. Literature suggests that most clinically relevant conditions are recognized during the history and physical examination without the need for further laboratory testing. The surgical team needs to ascertain the risks involved with the comorbidities that the patient may be suffering from, and be able to juxtapose this against the procedure-specifc risks to identify the overall risk of the procedure in that particular patient. Risk management and optimization strategies involve the rational use of adjunctive laboratory and imaging studies and professional opinions of consultants of other specialties. This helps evaluate the degree of physiological decompensation a patient might be having due to his comorbidities, and whether this could be either reversed or ameliorated. Acquiring informed consent from the patient involves the development of consensus between the surgeon and anesthesiologist frst, with regard to the perioperative plan, irrespective of whether the consent forms for anesthesia and surgery are the same or different documents. This proposed plan, which has the concurrence of both the surgeon and the anesthesiologist, is then presented to the patient along with clear information about the risks and benefts of different clinical strategies, such that the patient can make his up his/her mind, or else request refnement of the proposed plan. This thorough process of preoperative evaluation, it is expected, would be able to keep morbidity and mortality related to the maxillofacial surgery, to an absolute minimum.

#### **References**


B. Krishnan and S. Parida

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**3**

Aditya Moorthy and Shreya Krishna

#### **3.1 Introduction**

The management of the medically compromised patient is a topic that has received a great deal of attention in recent times. Unfortunately, most of the literature available discusses this topic from a western context. While the human species and the physiology remains unchanged, challenges in South Asia, especially India, stem from a vastly different social structure, a massive urban-rural socioeconomic divide, and social variables that have a major impact on the practice of medicine. In addition, a mixture of patient ignorance, poor training in soft skills of doctors, and an irresponsible fourth estate has vitiated a hitherto-friendly doctor-patient relationship.

While this chapter is not designed to provide a comprehensive guide to the medical management of a maxillofacial patient (which deserves a textbook in its own right), it attempts to provide an insight into the management of medically compromised patients requiring maxillofacial surgery.

#### **3.2 Changing Demographics in India**

India encompasses almost a ffth of the world's population with a population estimate of about 1.34 billion [1]. The life expectancy at birth in India has improved from 59.7 years in 1990 to 70.3 years in 2016 for females, and from 58.3 years to 66.9 years for males [1]. In short, the average life span of an Indian has increased by 11 years in the last decade leading to an increase in the geriatric population of the country. The crude death rate has also steadily declined in the last decade

A. Moorthy (\*)

from 7.5 to 6.4 per 1000 population [2]. The population continues to grow, as the birth rate has superseded the death rate. This change, while an indicator of improved healthcare delivery, adds to the health burden of the country, and creates a different spectrum of diseases—particularly lifestyle diseases.

There has also been a shift in the societal patterns. We see an increase in urban nuclear families resulting in unattended elderly parents whose medical conditions stay undiagnosed and uncontrolled.

#### **3.3 Lifestyle Changes in India**

There has been a sea of change in the lifestyle of today's population compared to a couple of decades ago. Sedentary lifestyle, processed food, industrialization, occupational hazards, etc. have led India to a "dual disease burden" scenario. So, even as the incidence of lifestyle diseases is steadily on the rise, a vast majority of rural and poor patients still suffer from infectious and acute diseases.

As recently as 2016, cardiovascular diseases like Ischaemic Heart Disease (IHD) and stroke contributed 28.1% toward mortality in India. This was a 34.3% increase over 16 years, suggesting the impact of lifestyle disease on society. The major contributors for this change are rapidly aging population, pollution, high blood pressure, dyslipidemia, high fasting plasma glucose, and an increased BMI (body-mass index) [3]. Respiratory diseases like chronic obstructive pulmonary disease (COPD) and bronchial asthma—are the second-largest contributors to the total mortality burden of India—at 10.9%. Diabetes analysis shows that it contributes 3.1% toward the total mortality burden.

Air pollution is a major risk factor for both cardiovascular and respiratory illness and increases the risks for acute respiratory infections and exacerbates asthma [4]. Such unique challenges raise questions of following treatment protocols based on western studies. A preoperative chest X-Ray may

**Management of Medical Comorbidities in Maxillofacial Surgery**

Rangadore Memorial Hospital, Apollo Hospitals, Bangalore, Karnataka, India

S. Krishna Oral and Maxillofacial Surgery, Rangadore Memorial Hospital, Bangalore, India

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_3

fnd an indication in an apparently ft and healthy 28-year-old living in New Delhi (with record levels of pollution) when it would be considered unnecessary for a similar patient from rural Yorkshire.

With the rise of urbanization and urban migration, the problems of air pollution, inadequate sanitation, and an unhealthy diet are accentuated. Population residing in urban areas in India, according to 1901 census, was 11.4%. This count increased to 28.53% by 2001, and the numbers increased to 34% in 2017 [5].

"Cyberchondria" has become a challenge with patients tending to diagnose and treat their problems themselves, and unsurprisingly getting it wrong. India is also among one of the most depressed countries in the world. A World Health Organization (WHO) study states that at least 6.5% of the Indian population suffers from some form of serious mental disorder. The average suicide rate in India is 10.9 for every hundred thousand people with the majority of victims being less than 44 years of age [6]. Diminished mental health is associated with a host of consequences like lack of participation in social activities, odd eating habits, and withdrawal from income generation and employment opportunities—all of which can cascade onto other serious illnesses and even death.

#### **3.4 The Changing Face of Oral and Maxillofacial Surgery**

As always, training is struggling to keep up with the changing trends in medicine. Trainees are often unaware of new protocols and the changed scenario of medical comorbidities of the population. Surgery has become heavily technology oriented, sometimes at the cost of clinical expertise. Furthermore, there is improved awareness among medical professionals for crossreferral to review dentition, seen mostly by maxillofacial surgeons rather than general dentists. Referrals are required now before radiotherapy, chemotherapy, cardiac surgery, transplants, etc.

Furthermore, maxillofacial surgery as a specialty has blazed a trail hitherto unimagined with successful foray into head and neck surgery, craniofacial reconstruction, and microvascular surgery. This now has put the onus on the surgeon to educate himself enough to be able to manage a sick patient on the ward to the extent of preventing complications and making appropriate referrals. Gone are the days when a physician could be asked to do the job for us and we could enjoy the comfort of being surgical technicians!

#### **3.4.1 Medical History and India**

While veritable treatises about the science and art of history taking, this part of clinical medicine is a unique investigative effort in the Indian context. The challenges to the maxillofacial surgeon are multifold. The frst diffculty is encountered with the patient who may deny illness (often hypertension or diabetes) because he/she is adequately treated and all parameters are within normal limits. The next hurdle is when the patient decides to withhold information wantonly due to social taboos or plain ignorance of its importance to the treating doctor. Dentists and maxillofacial surgeons who question their patients seated on dental chairs in an outpa-

tient setting often experience the latter. This stems from the patients' assumption that the information is inconsequential to their treatment. The last situation is the uneducated patient who is truly unaware of his medical condition. With these intricacies, the oral surgeon needs to employ several out-of-the-box techniques to extract the history.

This includes the much-derided leading questions, questioning relatives, sometimes in private, and playing Sherlock by asking them to bring in their medication and working backwards. But this effort is still of paramount importance in this technology-driven age and the modern oral and maxillofacial surgeon will do well to assimilate all the conventional history-taking skills and learn a few new ones as well.

#### **3.5 Cardiovascular System**

#### **3.5.1 Hypertension**

Hypertension is an extremely common condition and often undiagnosed. Since it is mostly asymptomatic, the oral surgeon has the unique opportunity to be the frst healthcare professional to identify the condition. Hence, it is imperative that every procedure should begin with recording the patients' vital signs. The following table offers a guideline for the diagnosis and risk stratifcation of hypertension (Table 3.1).

The authors stress that aneroid manometers are more accurate than digital ones. Like any delicate instrument, these too need frequent calibration [8].

The long-term effects of hypertension have far-reaching implications on maxillofacial surgery, especially under general anesthesia (Fig. 3.1).


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 3.1** Long-term effects of hypertension

#### **3.5.1.1 Minor Oral Surgery**

A thorough history will elicit symptoms of poor blood pressure control and symptoms of end-organ damage in a known hypertensive.

Conversely, end-organ damage points to poor blood pressure control. If such symptoms exist, elective procedures are to be deferred until good control is achieved. The absolute cut off of blood pressure is supposed to be 180/110 mmHg [9]. However, it is the author's experience that this is too high a cut off in the Indian context with social and logistic challenges. This is especially true for an out-of-hospital standalone dental clinic where the average oral surgeon performs his outpatient procedures. This is because there is a lack of clarity on the effect of stress-induced hypertension (white coat hypertension) and the effect it can have in an alreadyhypertensive patient. Hence, it is advisable to limit elective extractions to stage 2 hypertension [10] (SBP < 160 mmHg and DBP < 100 mmHg). When minor oral surgery is performed within these parameters, excessive bleeding is an unlikely complication.

#### **3.5.1.2 Major Maxillofacial Surgery**

Major surgery introduces two important variables into the mix. First is the procedure itself with surgical trauma and the attendant physiologic response (Table 3.2). The second is the requirement of a general anesthetic. While the anesthesiologist takes the fnal call on the safety of administering general anesthesia, the surgeon is the one who needs to provide the input regarding the intensity of the surgery. For example, fxing a fractured zygomatic bone can wait while operating on a patient with stridor from Ludwig's angina cannot.

Additionally, perioperative hypotension can also be of signifcant concern, both systemically and surgically (microvascular faps need excellent perfusion and hypotension with peripheral vasoconstriction can lead to a fap loss). The surgeon and the anesthetist need to walk a tightrope, especially in a hypertensive patient.

#### **Table 3.2** Causes of hemodynamic changes [7]


#### **3.5.1.3 Vasoconstrictors and Hypertension**

Vasoconstrictors are routinely used in conjunction with a local anesthetic to reduce bleeding, increase the duration of action, and reduce the requirement of the total volume of the anesthetic. The most commonly used vasoconstrictor is adrenaline. Felypressin (Octapressin) is also available as a vasoconstrictor with Prilocaine—but only in a cartridge. The concentration of adrenaline as a vasoconstrictor ranges from 1:80,000 to 1:200,000.

Physiologic effects of adrenaline in varying concentration [11]:


Pain itself has a signifcant effect on SBP, DBP on heart rate and adrenaline, even in the concentration of 1:200,000 signifcantly increases the duration and depth of local anesthetic. Adrenalin has a benefcial effect in this concentration without negative cardiovascular implications [11].

### **3.5.2 Ischemic Heart Disease (IHD)**

Atherosclerosis is a progressive disease involving mediumto-large caliber arteries. It may result in ischemic lesions of the brain, heart or extremities leading to thrombosis, infarction of affected vessels, and end-organ damage.

Ischemic heart disease could present as angina or myocardial infarction (Figs. 3.2 and 3.3). Both conditions are caused

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 3.3** Types of Acute Coronary Syndrome

by decreased coronary blood fow, increased myocardial oxygen demand, and form two ends of a spectrum with several subclassifcations.

Oral surgical procedures cause signifcant surgical, physiological, and psychological stress. It is imperative that the patient is assessed thoroughly prior to any intervention. Patients with IHD are susceptible for another cardiac event within 6 months [12]. With changing management strategies in cardiac patients and medicolegal aspects in mind, it is prudent to liaise with the cardiologist for all but the most straightforward of situations.

#### **3.5.2.1 Minor Oral Surgery**

Previous myocardial infarction or unstable angina does not form a contraindication for dental extractions. However, timing and planning are of paramount importance. In the quoted study, about 10% of patients have reported postoperative chest pain [12]. While the sample size of the quoted article is small, it underscores the importance of risk-beneft analysis before undertaking these procedures. The treatment planning may need further input from a cardiologist.

If such patients are on antiplatelet medication, it is of extreme importance to note that single antiplatelet agents do not constitute a contraindication for most minor oral surgery [13]. *Refer to the section on antiplatelet and anticoagulant drugs and surgery.*

#### **3.5.2.2 Major Surgery**

Since most surgery considered in this context is emergent or urgent in nature (trauma, oncosurgery, space infections), the benefit of the life-saving procedure by far outweighs the risk of a further cardiac episode. Such procedures are ideally done in a center equipped to deal with any adverse cardiac event. In a country like India, the onus of keeping the appropriate specialty appraised of the situation before starting the procedure is on the operating surgeon.

#### **3.5.3 Postintervention Cardiac Patients**

#### **3.5.3.1 Percutaneous Coronary Angioplasty (PTCA) and Coronary Artery Bypass Graft (CABG) and Valve Replacement Procedures**

With access to healthcare improving, it is becoming more common for the surgeon to encounter patients with IHD who have had interventions. These range from conventional CABG to Percutaneous angioplasties with stents in place and minimal access CABGs. In our context, the clinician needs to know what these are not only to analyze the impact these procedures have on the maxillofacial procedure but also to tease the information out of the reluctant historian.

#### **PTCA/PCA**

Percutaneous transluminal coronary angioplasty has become the intervention of choice for coronary artery disease. This procedure involves the insertion of a stent in the narrowed portion of the artery (Fig. 3.4). This stent intimately hugs the endothelium of the vessel and is reliably and completely endothilized in 6 months to a year. The patient is susceptible to stent thrombosis in this period and hence the antiplatelets. There are many varieties of stents and the design and features are always in a state of fux. Therefore, any changes to antiplatelet therapy are to be made in consultation with the treating cardiologist [14].

Types of coronary stents:


Following successful revascularization procedures, the patient is expected to be in a far better hemodynamic state than before. If the patient remains symptomatic, then he/she requires to be seen by the cardiothoracic surgery team. The only challenge in these patients is the antiplatelet/anticoagulant medication. In the case of patients with prosthetic cardiac valves, it is vital to provide endocarditis prophylaxis (read following content).

#### **3.5.4 Conventional Antiplatelets, Anticoagulants, and Novel Oral Anticoagulants (NOAC)**

#### **3.5.4.1 Minor Dentoalveolar Surgery: Antiplatelets**

There are several concerns regarding the risk of excessive bleeding following minor oral surgery in anticoagulated patients and those on antiplatelet medication. Most of these are unfounded for dentoalveolar procedures. In most dentoalveolar procedures, we have the advantage of a bony cavity where physical pressure can be effectively applied to obtain hemostasis. This can be further augmented with other local hemostatic measures (sutures, surgical R, AbgelR, etc.). This obviates the need to stop antiplatelet drugs (read following content). However, in patients on dual antiplatelet therapy, the authors suggest caution when operating in critical areas like the foor of the mouth as hematomas can cause airway embarrassment.

Conventional antiplatelets bind irreversibly to platelets and the normal clotting process is restored only with the production of new, unaffected platelets (Fig. 3.5, Table 3.3). It takes 5–10 days for platelets to be produced in the quantity required to produce a clinically normal platelet action. In the interim, if a procedure causes excessive bleeding, the only reliable way to ensure hemostasis is platelet transfusion. However, the newer ones are reversible and can be stopped for 24 h prior to the procedure as a "switch on-switch off"

**Fig. 3.5** Mechanism of action of commonly used antiplatelet drugs


**Table 3.3** Commonly used antiplatelet agents and their characteristics [15]

drug. But these are very expensive and most of the belowpoverty-line patients are likely to be on older antiplatelets for some time to come.

Deep Vein Thrombosis and Pulmonary Embolism. Myocardial infarction. Acute Ischemic Stroke

#### **3.5.4.2 Maxillofacial Surgery**

Patients who need procedures with low risk of bleeding (e.g., fxation of fracture of the parasymphysis) may continue oral antiplatelet/anticoagulation therapy. This applies especially to high-risk patients (e.g., mechanical heart valves). However, when the risk of bleeding is obvious, it outweighs the beneft of continuing antiplatelet/anticoagulant therapy. In such cases, heparin is used as bridge therapy.

#### **3.5.4.3 Bridging with Heparin**

In cases where the patient is at high risk for a thromboembolic episode, a "bridge"—a balance between surgical bleed and risk of thrombosis may be achieved either with intravenous unfractionated heparin or with subcutaneous lowmolecular-weight heparin [16].

#### **3.5.4.4 Anticoagulants and Oral/Maxillofacial Surgery**

While several indications exist for the use of anticoagulants, the authors have noted that there is signifcant resistance in the medical community to prescribe anticoagulants in these cases and they are often replaced by antiplatelets in India. This is especially true for the rural patient who may not have regular access to monitor his anticoagulation status. However, in urban centers, NOAC are in regular use.

Common indications for anticoagulation—prevention of thrombotic events in:

Mechanical Heart Valves. Atrial Fibrillation.

The target International Normalized Ratio (INR) range for most conditions is between 2.5 and 3.5.

#### **3.5.4.5 Minor Oral Surgery**

It is beyond doubt that warfarin/acetrom therapy need not be discontinued and INR need not be normalized prior to dentoalveolar surgery. The risk of a thrombotic episode does not justify the risk of a minor bleed that can be controlled by local measures [17]. Simple dentoalveolar surgery (e.g., three simple extractions) can be safely performed with an INR of 3.5 or less with appropriate local hemostatic measures [18]. However, it is imperative that the patient is closely followed. It is sensible to schedule these procedures in the morning.

#### **3.5.4.6 Major Maxillofacial Surgery**

Depending on the indication for anticoagulant therapy and the drug used, the decision regarding the control of anticoagulation is made. Ideally the prescribing physician is involved in decision making (Fig. 3.6) (read following content).

#### **3.5.5 Infective Endocarditis Prophylaxis**

Much has changed over the years with regard to infective endocarditis (IE) and antibiotic prophylaxis. Since the guidelines change by the year, the authors strongly recommend that the surgeon takes recourse to his smartphone to keep abreast of the changing scenery (Tables 3.4 and 3.5).

**\***OAC; Oral anticoagulant,POD; Post-operative day, INR; International normalized ratio, LBR; Low bleeding risk, SBR; Standard bleeding risk, HBR; High bleeding risk, CrCl; Creatinine clearance ©Association of Oral and Maxillofacial Surgeons of India

**Fig. 3.6** Perioperative management of oral anticoagulants [19]

#### **3.5.6 Implantable Cardioverter Defbrillators (ICD)**

An ICD is a battery-powered device implanted in a patient that generates a small electrical impulse. Indications are patients at risk of sudden cardiac death—ventricular fbrillation/ventricular tachycardia, malignant ventricular tachyarrhythmias. ICDs are also used to treat Brugada syndrome [21].

#### **3.5.6.1 Implications**

Bleeding: patients may either be on antiplatelets or anticoagulated. (read earlier content).

Devices: Electrocautery, especially monopolar diathermy, may interfere with the device and this may have to be turned to a "safe mode" by the electrophysiology technician. The concerned cardiologist should be able to assist with the technical details.

Infective endocarditis prophylaxis: Risk being low, current guidelines DO NOT recommend prophylaxis for these patients.

#### **3.6 Impact of Central Nervous System Disorders in Maxillofacial Surgery**

Of the many conditions which affect this system, the effects of epilepsy and stroke are most commonly encountered in maxillofacial surgical practice.

**Table 3.4** AHA, ESC, and NICE guidelines for infective endocarditis prophylaxis



**Table 3.5** Revised AHA guidelines for infective endocarditis prophylaxis [20]

Note: *i.m* intramuscular; *i.v* intravenous

a Or other frst- or second-generation cephalosporins at equivalent adult and pediatric dose

b Cephalosporins should not be given to a patient with a history of anaphylaxis, angioedema, or urticaria with penicillin or ampicillin

#### **3.6.1 Epilepsy**

A seizure is a result of excessive electrical discharges in a group of brain cells, whereas epilepsy is described as a disease characterized by recurrent seizures. A single seizure does not constitute epilepsy, which is defned as having at least two or more unprovoked seizures. The incidence worldwide is approximately 0.5–0.9%, affecting over 50 million individuals [22].

Etiology of epilepsy can be divided as primary or idiopathic, where the cause is unknown and this constitutes the vast majority of cases. In secondary or acquired epilepsy, the cause can be determined and these include metabolic, genetic, structural, and functional abnormalities.

An increase in the incidence in the elderly can be attributed to conditions such as stroke, tumors, trauma, and Alzheimer's disease. Systemic conditions include diabetes, hypertension, infections, electrolyte imbalances and dehydration, or lack of oxygen. Withdrawal from high-dose, long-term use of drugs such as cocaine, heroin, barbiturates, amphetamines, and alcohol can also precipitate seizures [23]. Seizures generally last for a few seconds to minutes. Although many types exist, they are broadly divided into two groups (Fig. 3.7).

Primary generalized seizures—which begin with involvement both sides of the cerebral hemispheres.

Partial seizures—start in a localized area [25].

#### **3.6.1.1 Basic considerations**

While recording history, the duration, type, frequency of the seizure as well as the most recent episode must be recorded as well as the type of medication taken, if any. If the patient is aware of how the seizure starts, if there is any warning or "aura," this too must be noted [23].

Several factors are capable of provoking seizures. These include improper use of medication, lack of sleep, drug abuse, drug interactions, hypoglycemia, electrolyte imbalance among others. Antiepileptic drugs should generally be continued without alteration.

#### **3.6.1.2 Outpatient maxillofacial considerations**

If seizures are predictable, then appointments should be scheduled accordingly. Frequency of seizures determines the urgency of treatment. Procedures, unless emergent, should be postponed if frequency of seizures is high. The clinician must reduce anxiety to the patient. Short morning appointments are ideal. Sudden bright lights, noise, or movements must be avoided as these may trigger a seizure [23].

#### **3.6.1.3 Major Surgical Considerations**

Trauma is a common consequence of seizures and may result in lacerations of the face or oral cavity and fractures of the maxillofacial skeleton. Other injuries include hematomas, dislocation of temporomandibular joint (TMJ) fracture/loss of teeth. An electroencephalogram (EEG) along with imaging such as CT/MRI is recommended if there is no previous seizure history. Open reduction should be preferred over closed for treatment of facial fractures, as further episodes of seizures might lead to aspiration if intermaxillary fxation (IMF) is attempted [25].

Local anesthetic is considered safe in well-controlled epileptics, as is sedation. General anesthesia is preferred in uncontrolled epileptics, especially if coupled with a mental defcit, as a seizure might be triggered due to stress from diffculties in communication. One drawback of general anesthetic is temporary anoxia to the brain, which itself might trigger a seizure [26].

#### **3.6.1.4 Precautions, complications, & management**

As mentioned earlier, appropriate recording of history gives an insight into planning the procedure, particularly for elective surgeries. Objects with the potential to cause harm must be kept away from the vicinity of the patient. Antiepileptics such as phenytoin have been known to cause gingival enlargement, which can be managed either by surgery or by a change in medication. Aspirin, antifungal azoles, metronidazole can interfere with phenytoin. Propoxyphene and erythromycin can interfere with carbemezepine. Contraindicated drugs are chlorpromazine, fumazenil, ketamine, lignocaine in large doses and quinolones, tramadol, and tricyclic antidepressants [25].

#### **3.6.1.5 Management of an acute episode on the dental chair**

If possible, all foreign body/material should be removed from the oral cavity. The chair should be reclined to a supine position with the patient turned onto their side to minimize the

©Association of Oral and Maxillofacial Surgeons of India

risk of aspiration. Passive restraint is used only to prevent them from falling out of the chair. A recurrent seizure or a seizure of more than 3 min requires drug administration. The patient should be monitored to prevent airway obstruction. After the patient recovers, appropriate medical consults should be arranged. Elective treatment should be postponed [23]. However, prolonged seizures, which continue in spite of medication, may lead to status epilepticus, which may be fatal if untreated. Airway patency and peripheral venous access are frst line of management. If seizures persist even after administration of drugs such as lorazepam or diazepam, the patient must be shifted to the hospital for further management.

#### **3.6.2 Stroke**

Stroke (cerebrovascular accident) is a serious, occasionally fatal neurologic event characterized by the rapid appearance of a focal defcit of brain function. It is estimated that 85% of patients presenting with stroke would have sustained a cerebral infarction because of inadequate blood fow to a part of the brain, with the remainder suffering from an intracerebral hemorrhage. Often, survivors of cerebrovascular accidents are left debilitated in motor function and/or speech [27].

A stroke may be a result of hemorrhage or ischemia as given later (Fig. 3.8).

The initial presentation of stroke includes loss of combination of sensory and motor functions with occasional loss of consciousness. The presenting features include hemiparesis or paraparesis, dysphagia, ataxia, aphasia, dysarthria, loss of vision. Early detection is by assessing facial and arm weakness and any slurring of speech. Mechanism of stroke may be ischemic, primary intracerebral hemorrhage, and subarachnoid hemorrhage. The oral impact of stroke includes facial weakness, dysphagia, and speech impairment [29].

#### **3.6.2.1 Basic Considerations**

At the outset, it is paramount to assess the extent of disability of the patient—both physical and mental, as this is vital in determining whether performing the procedure is safe in the outpatient setting. There may be a dependence on others for basic needs. History of past strokes needs to be elicited: including dates, severity and current neurological defcit. Treatment is performed in consultation with the neurologist and precautions according to the specifc characteristics of the stroke.

#### **3.6.2.2 Maxillofacial considerations**

Outpatient appointments must be ideally scheduled in the morning and must be of short duration. Patients must be treated in an upright position as much as possible, as they are more prone to aspiration due to impaired protective refexes. Another important consideration is diffculty in oral hygiene maintenance due to facial weakness and xerostomia, which may be observed as a side effect of medications prescribed [24]. Although procedures must be deferred for as long as possible, in unavoidable circumstances such as trauma or progressing head and neck cancers, general anesthesia is reasonably safe. Shorter duration surgery, intraoperative monitoring and maintaining cerebral perfusion, anticoagulation status, and precaution all aid in reducing the incidence of a further episode.

Antiplatelets and anticoagulation: Ref previous section.

#### **3.6.2.3 Precautions**

Monitoring of Blood pressure pre- and postprocedure is vital, procedures should be deferred if systolic is >180 mmHg or diastolic is >110 mmHg. Poststroke patients are usually on antiplatelet or anticoagulant medications; hence, coagulation status must be ascertained prior to any procedure. Vasoconstrictors are to be used cautiously as they can increase the risk of adverse outcomes like cerebral hemorrhage due to acute hypertension [29].

Opiods are best avoided as they may result in severe hypotension and benzodiazepines may cause respiratory depression. The practitioner must be mindful that sudden loss of consciousness could result from stroke, and emergency management is the protection of airway and shift to hospital [24].

**Fig. 3.8** Common causes of stroke [28]

### **3.7 Impact of Psychiatric Disorders in Maxillofacial Surgery**

Psychiatric and psychological disorders are of rising concern in modern society, affecting all aspects of a patient's life, including oral health. Poor oral hygiene is usually due to a combination of lethargy, side effect of medications, and possibly fear of treatment [30]. Common disorders encountered in practice are related to mood, anxiety, substance dependence, eating, or somatoform in nature [31].

Occasionally, oral symptoms may be the initial or single manifestations of the underlying issue. Patients who present with atypical facial pain with vague symptoms, oral dysesthesia, abnormal sensation or movement, salivation often with no identifable physical cause could be suffering from undiagnosed underlying emotional disturbances. Early detection in such cases benefts both the patient and the practitioner [32, 33].

#### **3.7.1 Maxillofacial Considerations**

Pain related to the TMJ and associated structures seems to be another condition, which fts into the previous category, commonly seen and treated by the maxillofacial surgeon. In the absence of an identifable organic cause, there must be a low threshold for considering an underlying emotional disturbance.

Patients with diagnosed psychiatric conditions and on medication present with obvious oral symptoms. Most common among these are dental caries and periodontal disease. The primary cause of these is due to decreased salivary fow or xerostomia, which is a side effect of medications, including tricyclic antidepressants, lithium carbonate, phenothiazines, and benzodiazepines. Sialorrhea or excessive salivation is a well-known side effect of clozapine and reduction in dose may be of use [32]. Candidiasis is another condition, which may manifest due to xerostomia, especially in denture wearers. Fear of dental treatment is well known. However, recognition of the nature and extent of this fear is important to prevent noncompliance. Anxiety disorders and phobia often stem from two types of experiences, a painful or traumatic procedure, usually at a young age, or a negative interaction with healthcare professional [32]. A specifc maxillofacial consideration in this respect is suturing of facial wounds under local anesthetic, in young children. The authors recommend sedation if not a general anesthetic, particularly in extremely young children, where such procedures are required.

Alcohol, tobacco, and drug abusers are particularly tricky to treat, be it minor or major maxillofacial surgery. The amount of local anesthetic required to produce adequate analgesia tends to be higher in such patients. These groups of patients are at a higher risk of developing oral cancer. Effects of withdrawal can be signifcant and this must be kept in mind preoperatively, intraoperatively, and postoperatively especially where procedures of long duration and extended stay are planned. Use of drugs like chlordiazepoxide might be required to offset delirium tremens, particularly in the postoperative period. Head and neck cancer particularly affects the psyche, making a psychologist a very important member of the multidisciplinary team.

Patients suffering from clefts of the orofacial region require multiple surgeries at various stages of their life and the effects of surgery and rehabilitation can be debilitating on both the child and the parents. Timing of surgeries is vital as they disrupt the life of the entire family of the child and for this parental counselling is extremely important [33].

While management of trauma might be comparatively straightforward, one must not underestimate the effect on the psyche in the recovery phase, especially if this is coupled with post-traumatic stress disorder (PTSD). Although these injuries are among the most common treated, these can lead to depression, drug abuse, antisocial behavior, especially in those with a post-traumatic residual defect [34].

Orthognathic surgery, while primarily carried out for cosmetic reasons, occasionally may be performed for functional reasons, as in obstructive sleep apnea. Counselling prior to surgery is useful and the entire process can take up to 3 years. Serious psychological and psychosocial problems have been reported [33].

While awareness of maxillofacial surgery and its benefts is gradually growing in our country, with most centers providing information about technical aspects of surgery, the psychological aspect is often ignored. Communication needs to improve and an assessment of patients' emotional state before and after surgery could help in improving patient satisfaction [33].

#### **3.8 Dental and Maxillofacial Implications in Liver Disease**

#### **3.8.1 Introduction**

At approximate of 1.4 kg, this reddish, rubbery structure forms an important organ system. Along with the Gall Bladder and Pancreas, the liver works to digest, process, and absorb food. Liver aids in detoxifcation in the body and is the primary organ of drug metabolism. It also helps in the production and transport of bile [35].

#### **3.8.1.1 The Function of the Liver** [36]

Detoxifcation—Removal of ammonia, exogenous hormones


Liver dysfunction hence alters all of these functions, thereby disrupting the homeostasis in the body, which has to be taken into consideration when providing dental and maxillofacial therapy.

Vitamin K levels are signifcantly lowered in advanced liver disease hampering the production of coagulation factors. This, along with portal hypertension, results in thrombocytopenia, thus resulting in excessive bleeding, which is of consideration during dental and maxillofacial management [37].

#### **3.8.2 Classifcation of Liver Dysfunctions** [35]

Acute or Chronic


#### **3.8.2.1 Viral Hepatitis**

Hepatitis A—caused due to Hepatitis A virus, spreads via the orofecal route. It is endemic in nature and is self-limiting.

Hepatitis B—caused by (HBV) that replicates within the hepatocyte; it is a dangerous form of viral disease with high risk to healthcare workers. The surface antigen is routinely detected in the saliva of infected individuals, and hence transmission through the saliva is of concern to the Oral Surgeon [38]. Prevalence of HBV infection is three to fve times more in dentists than the general population. Younger individuals with chronic HBV infections have a greater prevalence of developing hepatocellular carcinoma.

Hepatitis C—Caused by a bloodborne virus, it is the most common cause for chronic hepatitis, which over long term could lead to cirrhosis or hepatocellular carcinoma.

#### **3.8.2.2 Autoimmune Hepatitis**

It is a chronic liver infammatory disease as a result of IgG Hypergammaglobinemia as a result of environmental or viral factors inciting an autoimmune response leading to cirrhosis [39].

#### **3.8.2.3 Fulminant Hepatitis**

A sudden acute and severe dysfunction of the liver with resulting hepatocellular necrosis and encephalopathy with a very poor prognosis. These patients require liver transplant.

#### **3.8.2.4 Cirrhosis**

It is the irreversible damage to the hepatic architecture due to long-term fbrous scarring. A rise in the production of total liver collagen and matrix protein that is troublesome to the function and form of the liver [40].

#### **3.8.2.5 Hepatocellular Carcinoma**

It is the ffth most common cancer and a life-threatening malignancy with poor survival rates. HBV and HCV are the most common causes of it.

#### **3.8.2.6 Alcoholic Liver Disease**

It is the 10th most common cause of death with 3% of fatalities in the industrialized world [35]. Alcoholism results in varied disruption of the hepatic system ranging from simple fatty liver to complicated life-threatening cirrhosis.

#### **3.8.3 Oral Manifestations of Liver Disease**

Foetor hepaticus (Breath of the dead odor of rotten eggs with garlic) is a characteristic late feature of liver dysfunction [36]. Evidence of liver diseases has been noted in the oral cavity as icteric mucosal alteration with gingival bleeding and also associated hemorrhagic changes like hematoma, petechiae [37]. HCV-associated hepatitis is noted as a common cause for Sjogren's syndrome and lichen planus in the oral cavity [41]. Alcoholic hepatitis in association with nutritional defciencies could cause glossitis along with delayed healing post surgery [37]. Occasionally, parotid enlargement is also noted. These oral manifestations are associated with concomitant general symptoms of liver disease such as hepatomegaly, malaise, confusion, fatigue, weight loss, nausea, and altering the well being of the person [37].

#### **3.8.4 Implications of Liver Disease**


#### **3.8.4.1 Liver Disease and Maxillofacial Surgery**

Risk of viral contagion and crossinfection is one of the implications of viral hepatic disease. Hep C viruses are found to be stable at room temperatures for approximately 5 days. The virus is also detected at different surfaces in the clinic after the patient is treated. It is vital to maintain adequate sterilization and observe strict universal protection when treating such patients. Needlestick injury precautions must be adhered to.

Detailed history taking is important to identify any indications of liver disease, including that of hepatitis, jaundice, alcohol intake, recreational drugs, or rank abuse. Abnormal bleeding patterns are elicited in history [42]. Past surgical history provides a valuable indicator for any doubts regarding the adequate functioning of the liver system. Additional information of identifying the etiology for cirrhosis and any continued risk factors like alcohol consumption should be noted [35]. Review of blood investigations such as serum bilirubin, albumin, alanine aminotransferase (ALT), Aspartate aminotransferase (AST), complete blood counts, and coagulation profle must be performed prior to any surgical planning [43].

Elective surgery is contraindicated in acute phases of viral hepatitis and acute liver failure. Patients who present with hepatitis due to alcohol/drug abuse are poor candidates for elective surgery due to liver dysfunction and psychological impact of withdrawal during their hospital stay.

Plasma level of coagulation factors is depressed in liver disease and can potentially alter the hemostasis. Complete blood counts, PT, PTT, INR, and liver functions tests are mandatory in all patients with any signs/symptoms of liver dysfunctions. The goal of surgical therapy is to minimize trauma to the tissues. It is also advisable to involve the hematologist if required. Any dental or minor oral surgical procedure must terminate with the use of local hemostatic agents or antifbrinolytic agents to aid in hemostasis. Maxillofacial surgical work and major invasive oral surgery are ideally performed in the hospital. Fresh Frozen Plasma and Vitamin K infusions to optimize the coagulating process might be required to offset intraoperative bleeding.

Patients with liver disease are more susceptible to infection with a greater risk post invasive dental or maxillofacial procedure. Antibiotic prophylaxis is recommended.

Drug metabolism is altered in these patients (Table 3.6). Unlike serum creatinine, which is an indicator of renal function, the liver function test is more of an indicator for liver damage. Hence, it is diffcult to obtain exact dose modifcation formulae when medicating patients with liver disease. Drug usage, dosage, and interactions must be consulted with the specialist prior to their usage.

The metabolism of these drugs is well tolerated in mild liver dysfunctions but is impaired in severe dysfunction and hence requires modifcations and contraindications. The beta lactams mainly utilized in maxillofacial surgery are quite safe. NSAIDS are to be used with caution to avoid gastric bleedings [35]. Hepatotoxic drugs should be avoided eg. erythromycin, ketoconazole, halothane, phenytoin etc. Prilocaine or articaine is preferred over lidocaine. Sedatives,



hypnotics or opiods should be used with caution. A balance has to be struck constantly to maintain the anesthesia and concern is of the depressive action of alcohol and central nervous system depressors. Postoperative care in view of alcohol withdrawal must be noted. Ensure alcohol-based mouth rinses are avoided.

#### **3.9 Maxillofacial Implications in GI Disorders**

#### **3.9.1 Perioperative Maxillofacial Implications**

#### **3.9.1.1 GERD**

Extraesophageal symptoms of GERD must be identifed to prevent any airway issues primarily. Due to delayed gastric emptying, preoperative fasting hours must be prolonged. In high-risk patients, Proton pump inhibitors and H2 receptor antagonists are potent drugs to increase gastric pH and reduce secretions. Nasogastric suctioning through nasogastric tube aids in protecting the airway from gastric secretions during surgery. It is important to manage nausea and vomiting postoperatively effectively.

#### **3.9.1.2 Peptic Ulcers**

Stress reduction protocol is vital. GI symptoms from NSAIDS are delayed and identifed when the ulcers are in an advanced stage with a greater risk of bleeding. Corticosteroids must be avoided in these patients along with NSAIDS. GI bleeding due to ulceration could cause anemia and has to be managed prior to any surgery. Surgery is contraindicated in active peptic ulcers. Ranitidine, when used over a long phase for management, could cause thrombocytopenia [44].

#### **3.9.1.3 Ulcerative Colitis**

One must rule out anemia in these patients and assess the effect of long-term steroid therapy. Antibiotics such as clindamycin, ampicillin, and cephalosporins are implicated in aggravation of colitis and are hence avoided. If the patient has undergone Vitamin K malabsorption, its effects are considered.

Postoperative nausea and vomiting, though not a complication, is still detrimental in patient management perioperatively. Volatile inhalation anesthetic agents and opiod analgesics are emetogenic and need to be used with caution. Postoperative anxiety, dehydration, and pain could result in nausea and vomiting. Scarred ulcers in the duodenum delay gastric emptying resulting in vomitus. Antiemetics in these patients must be prescribed at the end of the surgery and dexamethasone 1 h prior to the surgery is helpful if not contraindicated. In high-risk patients, antiemetics must be administered prior to anesthesia itself [45]. Postoperative ileus could occur due to prolonged opiate use during anesthesia, decreased potassium levels, trauma or due to iliac bone harvesting as a complication or resultant severe pain.

#### **3.10 Pregnancy**

Pregnancy is often associated with changes in cardiovascular, endocrine, hematological, respiratory, gastrointestinal, and genitourinary system. These alterations may occasionally be subtle and can lead to disastrous complications if not identifed [46].

#### **3.10.1 Physiologic Changes**

There will be increase in the heart rate leading to an increase in cardiac output. Cardiac output increases mostly in the frst trimester and remains fairly unchanged with minimal increase in the fnal trimester.

During the second and fnal trimesters, a decrease in blood pressure and cardiac output may occur while the patient is in a supine position. This is caused by the gravid uterus compressing the inferior vena cava leading to a decreased venous return to the heart leading to hypotension, bradycardia, and syncope. This phenomenon is called *supine hypotension syndrome* [47].

The concentration of all coagulation factors, other than factors XI and XIII, is increased. As Thrombin-mediated fbrin generation increases during pregnancy, this combines with an increase in the aforementioned clotting factors and hematocrit, leading to the hypercoagulable state of pregnancy. This leads to a higher risk of deep vein thrombosis (DVT) and pulmonary embolism (PE).

In the abdomen, the enlarging uterus displaces the stomach onto the spleen and liver leading to high intragastric pressure. This and the delayed gastric emptying leads to regurgitation and gastric refux. Hyperventilation that begins in the frst trimester might increase throughout pregnancy. This has obvious implications on drug dosage, route and timing of administration.

In the frst trimester, glomerular fltration rate increases 30–50%, which results in an increase in clearance of creatinine, uric acid, and urea. This leads to a decrease in levels of the same. While prescribing drugs, doses may need to be increased to account for this rapid clearance [48].

#### **3.10.2.1 Minor Surgery**

While minor oral surgery is not a contraindication in the pregnant patient, it is advised that the oral surgeon should consult with the patient's obstetrician to address specifc concerns should dental emergencies arise during the frst trimester.

Unless emergency treatment is required, it is advisable to defer treatment during the frst trimester because of the potential vulnerability of the fetus. The second trimester is the safest time to perform the routine dental treatment. No elective treatment is advisable late in the third trimester.

#### **3.10.2.2 Dental Radiology**

Two important factors to be considered are the dose of radiation to be given and the time of gestation. Animal and human data clearly support the conclusion that no increase in congenital anomalies due to exposures totaling less than 0.05– 0.1 Gy during pregnancy. The amount of radiation used in dental radiographs is well below the threshold dose [47]. With modern features such as high-speed flm, fltration, collimation, and use of lead aprons, dental radiography is deemed quite safe.

#### **3.10.2.3 Major Surgery**

Elective surgery should be postponed until after delivery. If possible, nonurgent surgery should be performed in the second trimester when preterm contractions and spontaneous abortion are least likely. Fetal safety requires that potentially dangerous drugs are avoided and adequate uteroplacental perfusion is ensured. No anesthetic drugs have been proven to be clearly hazardous to the human fetus. However, teratogenic effects of nitrous oxide have been demonstrated in animal models following prolonged administration in high concentration [49].

Anxiety in itself leads to decrease in uteroplacental perfusion secondary to increase in circulating catecholamines. Appropriate timing of surgery and anxiolysis is of paramount importance.

#### **3.10.3 Drug Usage in Pregnancy**

Most drugs cross the placental barrier by simple diffusion. Hence, the major concern of drug administration during pregnancy is the potential of teratogenic adverse effects. The period of maximum risk for teratogenicity is during organogenesis. This occurs from the end of the predifferentiation period until the end of the 10th week after the last menstrual period (Table 3.7).

**Table 3.7** Commonly used safe and unsafe drugs during pregnancy [46]


#### **3.11 Endocrine Disorders**

#### **3.11.1 Diabetes**

Diabetes is an endocrine disease manifesting as hyperglycemia, leading to microvascular and cardiovascular complications. Type 1 diabetes mellitus is an autoimmune pancreatic beta cell destruction leading to inadequate production of insulin. In type 2 diabetes mellitus, there is a condition of insulin resistance in addition to defects in insulin secretion by the pancreatic beta cells, and increased endogenous glucose production, primarily by the liver [50].

The current recommendation for diagnosis of diabetes stands at >126 mg/dl of fasting plasma glucose levels or a 2-h plasma glucose level of 200 mg/dl [51]. The Endocrine Society guidelines indicate that patients with hyperglycemia and glycated haemoglobin (HbA1c) of 6.5% or higher can be identifed as having diabetes [52].

Optimal glycemic control is advised in each patient to avoid hyperglycemia or hypoglycemia. The surgical patient with diabetes is at higher risk of perioperative morbidity and mortality and subsequently longer length of hospital stays. This is mainly due to increased chances of surgical site infections and systemic infections, other complications like acute kidney injury, acute coronary syndromes, acute cerebrovascular accidents, hospital-acquired diabetic ketoacidosis, etc [53].

The stress of surgery and anesthesia derails the glycemic control of the patient due to the metabolic response to surgery. Nondiabetic patients evoke a catabolic response with a release of cortisol, glucagon, catecholamines, etc., promoting hepatic glycogenolysis and gluconeogenesis causing hyperglycemia. There is a catecholamine-induced inhibition of insulin production as well as insulin resistance. The type of anesthesia and the length of the procedure are also said to infuence the amount of catabolism [54].

The preoperative preparation for a diabetic patient begins with a thorough history, including the type and dosing of medications, any history of cardiac events, or diabetic ketoacidosis. ECG is mandated as these patients have a higher occurrence of hypercholesterolemia, hypertension, macrovascular disease, autonomic neuropathy, and hence silent ischemia. If the ECG does suggest so, further investigation is indicated [55].

Renal function tests should include serum urea and creatinine. Hypertension should be ruled out or treated if present. Diabetic neuropathy should be evaluated as it may cause aspiration, silent myocardial ischemia, or even sudden death. It may manifest as postural hypotension, heartburn, or resting tachycardia [56].

HbA1c is usually advised in diabetic patients undergoing treatment as it refects mean control over the previous 3 months. This allows one to estimate the quality of glycemic control before the consultation and adaptation of treatment to fxed objectives. It is also important to know the duration of the diabetes, dependence on insulin, and whether the glycemic control is achieved by oral hypoglycemics and lifestyle modifcation.

#### **3.11.1.1 Management of Patients Undergoing Procedures**

The recommendations for target glycemic control vary. The Endocrine Society and the American Diabetes Association/ AACE Practice Guidelines recommend that patients on insulin maintain a target preprandial glucose of less than 140 mg/ dl and a random Blood Glucose (BG) of less than 180 mg/dl for patients treated [52]. The Joint British Diabetes Societies guideline, however, recommends that insulin therapy be commenced when random blood glucose levels exceed 180 mg/dl [53].

#### **3.11.1.2 Preoperative Glycemic Control in patients on Oral Hypoglycemic Agents**

#### **3.11.1.2.1 Minor surgery**

Patient should adhere to his daily oral diabetic medication and follow his usual diet [50].

#### **3.11.1.2.2 Major surgery**


• (Dipeptyl Peptidase-4) DPP-4 inhibitors are not contraindicated throughout the perioperative period [54].

#### **3.11.1.3 Preoperative Glycemic Control in Type 2 Diabetics on Insulin**

Patients on basal insulin: If they are on twice daily dosing then morning dose to be reduced to 80% of normal dose; whereas if those on single dose then evening dose to be reduced to 80% [57].

If the morning glucose levels are above 120 mg/dl, Neutral protamine Hagedorn (NPH) insulin and premixed formulations are reduced by 20% the evening before surgery and by 50% the morning of surgery. If not, morning insulin dose is withheld [58].

Naturally, these are guidelines and the diabetologist will tailor the doses to the individual requirement of the patient.

#### **3.11.1.4 Preoperative Glycemic Control in Type 1 Diabetics on Insulin**

#### **3.11.1.4.1 Minor surgery:**


#### **3.11.1.4.2 Major surgery:**

These patients are at risk of developing stress-induced hyperglycemia and ketoacidosis and hence need insulin coverage during perioperative period. These patients should receive 80% of basal insulin dose the evening before surgery and on the morning of surgery in order to prevent hypoglycemia [54].

#### **3.11.1.4.3 Intraoperative glycemic control:**

The endocrine society recommends an intraoperative BG level within 180 mg/dl [52].

Levels above that are treated either with subcutaneous rapidacting insulin analogs or with an IV infusion of regular insulin. In patients undergoing short surgeries (under 4-h operative time), ambulatory surgeries, expected hemodynamic stability and those expected to resume oral diet soon can be managed with subcutaneous rapid-acting insulin correction scales [3]. When it is used, the BG should be checked every 2 h [52].

An IV insulin infusion is preferred where there is anticipated hemodynamic disturbance, signifcant fuid shifts, expected changes in temperature, inotropic support, or lengthy operative times (greater than 4 h). In this situation, hourly insulin monitoring is needed.

#### **3.11.1.4.4 Postoperative glycemic control:**

For noncritical and non-ICU patients, the subcutaneous sliding scale insulin is used with BG being checked every 2 h. If BG drops below 70 mg/dl, insulin is stopped and oral dextrose or iv dextrose is given. For patients in the ICU, continuous iv insulin infusion is given instead of the subcutaneous sliding scale for BG > 180 mg/dl. Oral antidiabetic agents are best avoided in hospitalized patients due to the limited data available on their safety and effcacy. DPP-4 has shown promising results for in-patient hyperglycemia control [54].

#### **3.11.2 Hypo/Hyperthyroidism**

The thyroid gland releases the hormone thyroxine (T4) and its active form T3. The thyroid hormones are released upon stimulation by the thyroid-stimulating hormone (TSH) released from the pituitary gland. This is, in turn, stimulated by thyrotropin release hormone (TRH). Secretion of T3 and T4 is regulated by the negative feedback loop modulating release of TSH [59].

Thyroid hormones play a critical role in maintaining metabolic homeostasis in the adult. Thyroid-related disorders are due to either overproduction of thyroid hormones (thyrotoxicosis) or hormone defciency (hypothyroidism). These situations may arise due to infectious, autoimmune, proliferative, or tumorous pathologies [60].

Most patients with well-compensated thyroid disease do not need special consideration prior to surgery. Patients with a newly diagnosed thyroid disorder around the time of surgery will need to undergo risk assessment and optimization before surgery.

Routine thyroid screening is not done for asymptomatic patients unless there is a reason to suspect thyroid dysfunction. Thyroid disease present with a myriad of symptoms clinically. These include-unexplained weight changes, and fne tremor or changes in bowel habits, skin, hair, exophthalmos, goiter, abnormal refexes. Palpitations, tachycardia, or bradycardia are common cardiovascular manifestations. In such situations as well as in patients with a known thyroid disorder, a TSH test should be included in the preoperative analysis [61].

#### **3.11.2.1 Hypothyroidism**

Hypothyroidism may be primary (due to thyroid disease) or secondary due to hypothalamo-pituitary disorders. Commonly, it is due to thyroid loss from surgery, irradiation, autoimmune diseases, or drug induced [59]. The diagnosis is confrmed by blood tests revealing low T3 and T4 levels and high TSH in primary and decreased TSH in secondary hypothyroidism. These patients pose challenges during perioperative period due to their effects on various organ systems.

#### **3.11.2.1.1 Physiologic Challenges**

Cardiac disturbances like increased peripheral vascular resistance, decreased cardiac output; Respiratory implications like increased incidence of pneumonia, impaired respiratory drive, respiratory muscle weakness. Decreased renal perfusion, decreased gastric motility, and slower drug metabolism need to be considered.

One of the most serious complications of surgery in hypothyroid patients is myxedema coma. It is associated with a mortality rate as high as 80%. It is characterized by altered mental status, which may manifest as coma or seizure, and hypothermia, bradycardia, hyponatremia, heart failure, and hypopnea. It is precipitated by surgery, infection, cold exposure, and administration of sedatives [61].

#### **3.11.2.1.2 Management**

A condition of euthyroidism is usually targeted preoperatively and elective surgery is usually postponed. Once TSH values normalize, surgery can be performed. Use of sedatives, benzodiazepenes and Opiods should be avoided [59].

For urgent and emergent procedures, surgery may be performed in mild-to-moderate hypothyroidism with levothyroxine cover preoperatively. Surgery should be postponed in patients with severe hypothyroidism in case of nonemergent surgery. In an emergency, thyroid hormone levels should be normalized as rapidly as possible, using IV levothyroxine in a loading dose of 200–500 μg followed by 50–100 μg IV daily [62].

#### **3.11.2.2 Hyperthyroidism**

It is commonly due to autoimmune disease (e.g., Graves' disease), multinodular goiter, or adenoma presenting as thyroid nodule. The diagnosis is confrmed by elevated serum T3 and T4. It usually causes exopthalmos, heat intolerance, anxiety, sweating, diarrhea, and weight loss [59]. It has a positive ionotropic and chronotropic effect on the heart coupled with decreased vascular resistance [61]. Hence, these patients manifest tachycardia, arrhythmias, or cardiac failure frequently.

Thyroid storm is a severe manifestation of uncontrolled hyperthyroidism and is characterized by tachycardia, confusion, fever, gastrointestinal complaints, and potentially leading to cardiovascular collapse. It is precipitated by pain, anxiety, trauma, or GA. Hence, elective surgery should always be postponed in patients with overt untreated hyperthyroidism. Hyperthyroidism is usually treated by β-blockers like atenolol or metoprolol as they decrease the sympathetic overactivity. When there is no time to render a patient euthyroid as in emergency cases, cardiac monitoring and adequate β-blockers with antithyroid medication should be given [61]. While epinephrine with lidocaine is not contraindicated, caution should be exercised. Benzodiapines should be avoided. Carbamizole causes agranulocytosis and this can manifest as oral ulcers.

#### **3.11.3 Adrenal Gland Disorders**

#### **3.11.3.1 Primary Adrenocortical Hypofunction**

Addison's disease occurs due to autoantibody-mediated destruction of the adrenal cortex leading to failed cortisol and aldosterone secretion. It may also occur due to tuberculosis, histoplasmosis, sarcoidosis, etc [59]. Due to lack of adequate corticosteroid production, these patients are prone to hypotensive collapse, hypoglycemia, profound weakness, and dehydration (Adrenal crisis).

Adrenal crisis is rare in outpatient oral surgery. However, patients with Addison's disease who need surgery should be covered with supplemental steroids. Drugs like barbiturates, azole antifungals, etomidates, phenytoin, and rifampins should be avoided as they accelerate cortisol metabolism.

#### **3.11.3.2 Secondary Adrenocortical Insufciency**

Corticosteroids are prescribed as long-term treatment for various ailments such as infammatory bowel disease, blood dyscrasias like idiopathic thrombocytopenia, rheumatologic disease, reactive airway disease, and immunosuppression for transplant recipients, etc. due to their immunosuppressive, anti-infammatory, metabolic, and hemodynamic properties. This external source of long-term steroid can lead to secondary adrenal insuffciency that may manifest in the perioperative period [63].

In a healthy individual, corticotrophin-releasing hormone (CRH) has a diurnal pattern of release from the hypothalamus. This in turn acts on the anterior pituitary to release the Adrenocorticotrophic hormone (ACTH). ACTH acts on the adrenal cortex to release cortisol (hydrocortisone), corticosterone, and mineralocorticoids. Circulating corticosteroids have a subsequent negative feedback effect on CRH and ACTH release. This constitutes the hypothalamic-pituitary adrenocortical (HPA) axis [59].

Normally, an unstressed adrenal gland secretes approximately 8–10 mg of cortisol per day (Table 3.8). Stress, such as illness or surgery, is the stimulus for raised production of cortisol. During surgical stress, the rate varies between individuals and also upon the type of surgery. It is usually up to 50 mg/day for minor procedures and up to 75–150 mg/day for more complex procedures, rarely exceeding 200 mg/day. However, patients on exogenous corticosteroids aren't able to secrete adequate amounts of corticosteroids in response to stress due to HPA axis suppression and a resulting low level of ACTH and CRH leading to atrophy of the zona fasciculate of adrenal cortex [63].This may predispose them to develop adrenal crisis, with rapidly developing hypotension, hypoglycemia, collapse, and even death [59].

Even though there is no consensus on the exact dosage of corticosteroids that leads to hypofunction of the adrenal cortex, doses greater than physiologic doses of cortisol lead to suppression [59]. HPAA suppression does not extend beyond 1 year after exogenous steroid therapy is stopped [64]. Hence, those at risk are:


These patients require steroid cover/supplementation when undertaken for surgeries. Most dentoalveolar and maxillofacial surgeries result in stress and hence require steroid supplements, but most other dental procedures do not require any additional steroid supplements [59].

Following table shows the normal corticosteroid response to the particular level of stress and the appropriate steroid cover needed in cases of adrenal suppression (Table 3.9):

During the procedure, blood pressure and blood sugar levels should be monitored. NSAIDs should be avoided to avoid increasing risk of peptic ulceration. Prophylactic antibiotics should be given in such patients to avoid postoperative infections.

#### **3.11.4 Renal Disorders**

The kidneys are responsible for eliminating metabolic waste; fuid and electrolyte homeostasis; and to maintain acid and base balance. The kidneys also affect the cardiovascular and hematologic systems.

**Table 3.8** Approximate potencies of systemic corticosteroids relative to cortisol [59]



**Table 3.9** Normal corticosteroid response to the particular level of stress and the appropriate steroid cover needed in cases of adrenal suppression [63]

The best parameter to assess the function of the kidneys is the glomerular fltration rate (GFR). It is measured by calculating the creatinine clearance based on serum creatinine (SC). The normal value of GFR for an adult male is 130 ml/1.73 m2 and is 120 ml/1.73 m2 for an adult female. Chronic kidney disease occurs when the GFR is reduced by at least 50 ml/min [65].

Patients with chronic kidney disease who are either on dialysis, dialysis naive, or renal transplant recipients or posttransplant patients require modifcation of treatment plan from a surgical point of view. These patients always have a risk of developing acute renal failure in the postoperative period either due to pre-existing renal dysfunction or solely due to the effects of surgery.

#### **3.11.4.1 Acute Renal Failure (ARF)**

ARF is the rapid loss of renal function over the course of days to weeks, resulting in the patient's inability to clear nitrogenous waste, including creatinine and urea, from the body [66]. The term Acute Kidney Injury (AKI) has replaced acute renal failure in current literature. Perioperative AKI is a leading cause of morbidity and mortality due to increased risk of sepsis, anemia, coagulopathy, and mechanical ventilation.

There are three types of ARF based on etiology: prerenal, renal, and postrenal causes. The most common cause of AKI in perioperative period is the prerenal cause and the ischemic acute tubular necrosis (renal AKI) due to hypoxic damage to medullary region secondary to hypovolemia, hypotension, and dehydration [67]. Prerenal AKI and ischemic ATN are a part of a spectrum of manifestations of renal hypoperfusion. Hypotension or hypovolemia may be due to preoperative factors like hemorrhage, diarrhea, fasting, use of diuretics, due to intraoperative factors like ongoing blood loss, activation of sympathetic refexes, and due to postoperative factors like intravascular volume depletion, myocardial infarction, etc [68]. Hypotension and hypovolemia result in activation of the sympathetic nervous system and the renin–angiotensin–aldosterone axis, which compromises GFR by inducing afferent arteriolar renal vasoconstriction. Other common causes of AKI are the use of NSAIDs, ACE inhibitors, nephrotoxic drugs like aminoglycosides, radiocontrast materials, myoglobin, hemoglobin, and amphotericin B. Pre-existing diseases like diabetes, hypertension, and obstructions of the urinary system also lead to perioperative AKI [68].

The strategy around perioperative AKI is ideally prevention. Preoperatively potential risk factors such as volume depletion, hypotension, sepsis, nephrotoxin exposure, and pre-existing chronic kidney disease should be identifed and elective surgery should be postponed till optimization is complete. Anemia should be corrected before surgery. The choice of fuid in intraoperative resuscitation is usually a balanced crystalloid solution like Ringer's lactate and not a chloride-rich crystalloid. Hydroxyethyl starch is best avoided. Mean arterial pressure should be maintained and hemodynamic stability is of utmost importance. Diuretics should be only given in cases of volume overload and not for increasing GFR. Norepinephrine is preferred over dopamine as it maintains renal perfusion pressure, but the role is still not very clear [67].

#### **3.11.4.2 Chronic Renal Failure (CRF)**

CRF is permanent renal insuffciency that develops over months or years caused by the structural and intrinsic damage of the glomerulus or tubulointerstitial system. This usually occurs when GFR is reduced by 50 ml/min. If necessary treatment is not started, most cases of CRF would lead to End Stage Renal Disease (ESRD). ESRD is maintained by regular dialysis or by transplant, in the absence of which, death may occur [68].

Preoperative assessment:

Detailed history and physical examination;

Cardiac work up as dictated by clinical symptoms. ECG and

Echocardiogram

Complete blood count

Metabolic panel, serum magnesium, and phosphorus levels Coagulation profle.

Coronary artery disease and congestive heart failure are commonly found in patients with ESRD and those on dialysis. Hence, cardiac workup and monitoring is required in the perioperative period. Maintaining euvolemia perioperatively in ESRD patients is mandatory. For patients not undergoing dialysis, euvolemia can be achieved with appropriate hydration or diuresis. Dialysis is usually performed a day before surgery to prevent fuid overload and to reduce uremic complications (bleeding). Postoperative dialysis helps to achieve euvolemia if large amounts of fuids were given during surgery. Heparin is withheld if dialysis is performed on the day of surgery.

Anemia complicates CKD due to the decreased production of erythropoietin. Transfusion should be considered in the perioperative period when hemoglobin levels fall below 8–10 g/dl due to surgical blood loss in patients with ESRD. If anemia has been detected, erythropoietin should be initiated several weeks before the elective surgery with iron supplementation to raise hemoglobin to the desired level. Patients who have ESRD may be susceptible to more intraoperative and postoperative bleeding due to platelet dysfunction caused by uremia. Hence, NSAIDs and dipyridamole should not be given within 72 h before surgery to patients who have ESRD due to their effects on platelet function. Hypertension and glycemic control should be tightly monitored in such patients as well.

These patients have ineffcient mechanisms of drug clearance that inherently predispose them to adverse drug responses. Hence, NSAIDs, aminoglycosides, benzodiazipines, morphine, and radiocontrast media are avoided. Drugs like propofol, fentanyl, and inhalational anesthetics are usually the preferred drugs of choice.

#### **3.12 Patients with Non-head and Neck Malignancies**

#### **3.12.1 Introduction**

The most common cancers in India in women are Breast, Oral, Cervical, ovary, and esophagus. Men tend to be afficted with head and neck cancers, lung, esophagus, stomach, and colorectal cancer [69]. The cancers that most commonly metastatize to the jaws and oral soft tissues are breast, lung, prostrate, thyroid, kidney, stomach, and colon [70]. Another group of malignancies that receive chemoradiotherapy are the lymphoproliferative and hematologic malignancies [70].

*Chemotherapy* is often employed either with an intent of palliation or for cure. It may be administered as adjuvant therapy or as neoadjuvant therapy. Cytotoxic chemotherapeutic agents have hematologic effects (myelosuppression) as well as nonhematologic effects. The effects of myelosuppression, i.e., leukopenia, thrombocytopenia, and anemia start after 5–7 days with the nadir occurring at 10–14 days. It is usually followed by bone marrow recovery [71]. Hence, the oral surgical treatment should be planned in a manner that it doesn't coincide with the nadir of the myelosuppression where the neutropenia can be as low as 500.

*Radiotherapy* is a part of treatment for a variety of Head and neck cancers either as primary treatment modality or as adjuvant therapy to the primary tumor or to the associated lymphatic structures. Unlike the effects of chemotherapy, effects of radiotherapy are more long lasting. These include mucositis, xerostomia, trismus, radiation-induced fbrosis, and dysguesia.

#### **3.12.2 Treatment Protocol**

#### **3.12.2.1 Chemotherapy**

It is best to undertake a dental screening before the start of the chemotherapy so that the hopeless teeth can be extracted, be restored, periodontal therapy, alveoloplasty be performed, and primary closure be done. After extraction, it takes approximately 10 days to 6 weeks for healing to be enough for chemotherapy to start [72]. Ill-ftting and loose dentures should be discontinued and replaced ideally with implants especially in patients scheduled to take systemic bisphosphonates or RANK-L therapy as it might lead to osteonecrosis of the jaws [73]. Fluoride treatment can also be done.

However, patients suffering from leukemia, lymphomas have a state of myelosuppression even before the start of the


**Table 3.10** Modifcation of invasive dental treatment according to hematologic indices [75]

chemotherapy. Only acute situations need to be dealt with. Elective treatments can wait till the time the patient is in optimal clinical and hematological parameters, which is usually until after chemotherapy is over. Hence, extractions of grossly carious and severely periodontally compromised teeth, ill-ftting denture, etc. should be addressed. For extractions to be done, or other invasive dental procedures, hematologic indices should be evaluated and antibiotic prophylaxis should be considered [74] (Table 3.10).

Once the chemotherapy starts, a gap of 1 week before the next cycle is essential before any dental intervention. For surgical procedures that cannot wait, like facial trauma or infection, the complete blood counts should be assessed and consultation should be sought with the medical oncologist to determine the nadir in blood counts, the timing of the chemotherapy cycle, and duration [72]. For platelet levels below 40,000/mm3 , platelet transfusions are usually needed [76].

Opportunistic infections may complicate mucositis and may be of viral, fungal, or bacterial origins. Treatment should be guided by culture and sensitivity. Febrile neutropenia needs to be treated usually by intravenous antibiotics like amoxicillin and clavulanic acid with a fuoroquinolone or clindamycin with fuoroquinolone. Hematopoeitic growth factors like granulocyte colony-stimulating factors or granulocyte-macrophage colony-stimulating factors are effective drugs for prophylaxis and treatment of febrile neutropenia. Mucositis occurs in almost all patients and causes great diffculty in feeding, hydrating, and causes pain. It is preferable to manage it with saline mouth rinses rather than with chlorhexidine mouthwashes. Some chemotherapeutic agents are also neurotoxic and cause a deep mandibular pain as well as altered taste sensation and dysguesia. Most of these symptoms subside after cessation of treatment [72].

#### **3.12.2.2 Radiotherapy**

The same prophylactic measures of extraction, restoration, alveoloplasty, etc. have to be taken before radiotherapy as for chemotherapy. Additionally, jaw-opening exercises should be initiated and coronoidectomy should be considered as a part of the ablative procedure [72].

#### **3.12.3 Prevention and Treatment of Osteonecrosis After Chemotherapy and Radiation**

Osteonecrosis of the jaws occurring in an irradiated bone is called osteoradionecrosis (ORN). Those occurring in a patient on antiresorptive therapy like bisphosphonates or monoclonal antibodies to RANK-L is termed Antiresorptive osteonecrosis of jaws (AONJ) [72]. The incidence of ORN in areas of jaws that have received greater than 60 Gy of radiation is 5–15%. Incidence of AONJ in patients who have received denosumab is 1.3% and is 1.8% in patients treated with nitrogen-containing bisphosphonates [77, 78].

**Acknowledgments** Dr Prithvi Bachalli, Consultant Oral and Maxillofacial Surgeon Rangadore Memorial Hospital, Bangalore

Dr. Prashanth Bhat, Consultant Oral and Maxillofacial Surgeon

Rangadore Memorial Hospital, Bangalore Dr Shobha Hegde, Registrar Oral and Maxillofacial Surgeon

Rangadore Memorial Hospital, Bangalore

#### **References**


of the Nation's states-The India state-level disease burden initiative. New Delhi: ICMR, PHFI and IHME; 2017. https://www.healthdata.org/sites/default/fles/fles/policy\_report/2017/India\_Health\_ of\_the\_Nation%27s\_States\_Report\_2017.pdf


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Medical Emergencies in Oral and Maxillofacial Surgical Practice**

Nallamilli V. S. Sekhar Reddy

### **4.1 Introduction**

Oral and Maxillofacial Surgery has evolved over the last few decades. Although it is now practiced as a full-fedged hospital-based specialty, a signifcant amount of work is still carried out under local anesthesia; predisposing toward a medical emergency precipitated particularly by stress. Oral and Maxillofacial surgeons thus deal with the medical emergencies in an offce or hospital setting on a regular basis.

Emergency team response in most countries is prompt. The published guidelines from these countries refect this in the advice for the general practitioner; doing the essential minimum toward the sustenance of life in case of a medical emergency and to prioritize escalation of call for help to the emergency team. However, in some parts of the world, the response time of the emergency team is expected to be comparatively longer, due to various policy issues. The chapter considers these special circumstances, to suggest some additional measures toward the management of the emergency, while waiting for the arrival of the emergency team.

Also, the general advice in the management of a medical emergency during an outpatient procedure in a clinic is aimed at general practitioners, who may not necessarily be exposed to training in clinical skills like the placement of an intravenous cannula. Oral and Maxillofacial surgeons are expected to be well versed with this life-saving simple clinical skill and the protocols discussed here take this into consideration.

The management of emergency should follow the universally accepted ABCDE approach [1], which helps the clinician to follow a systematic approach in an emergency situation where the most life-threatening condition is assessed and is given the top priority. Lack of airway kills the patient frst, then the lack of ability to breathe followed by the absence of circulation. ABCDE approach incorporates:

Panineeya Institute of Dental Sciences and Research Centre, Hyderabad, Telangana, India


Medical Emergencies that are life threatening and need immediate remedial measures on an emergency basis are discussed here:


### **4.2 Acute Asthmatic Attack**

Stress, Anxiety, and Infection can precipitate an asthmatic attack in individuals who are prone. Unfortunately, all three of them can be part of OMFS practice.

#### **Box 4.1**

Note: Asthma that is part of a generalized anaphylactic reaction needs Adrenaline via intramuscular route.

#### **Signs and Symptoms:**


**4**

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 49

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_4

N. V. S. Sekhar Reddy (\*)


#### **Management:**


### **4.2.1 Life-Threatening Acute Asthma**

Asthmatic attack can sometimes be severe and may fail to respond to standard bronchodilator therapy. This can be fatal if no proper treatment is given. When an asthmatic attack failed to respond to the treatment and getting worse, the patient will need urgent transfer to appropriate medical center.

#### **Signs and symptoms of severe life-threatening asthma:**


#### **Treatment:**


### **4.3 Acute Adrenal Insufciency/Adrenal Crisis/Steroid Crisis/Addisonian Crisis**

Sudden and severe hypotension in patients who cannot mount a normal stress-induced cortisol response. The stress can be physiological or psychological. Adrenal crisis can be seen in patients who were taking glucocorticoids regularly or who have taken glucocorticoids for a considerable period of time in the past, patients with Addison's disease, hypopituitarism, or in other conditions associated with decreased adrenocorticotropic hormone (ACTH) production.

#### **Box 4.2**

*Oxygen—Supports Combustion*


*Do not oil, grease, or lubricate cylinder controls.*

#### **Signs and Symptoms:**


#### **Treatment:**

	- Children from age 2 to 11 years, 2–4 mg/kg body weight.
	- Above 11 years: give adult dose.
	- Adult dose: 100 mg by IV.
	- If unable to secure IV access, give the same dose by IM route.

### **4.4 Airway Obstruction**

As the mouth is the primary area of our specialty, clinicians may have to deal with acute airway obstruction. As with everything else, prevention is the most important thing.

#### **Signs and Symptoms:**


#### **Treatment** [7]:

	- Start with chest compressions even if there is pulse, as chest compressions can help relieving the obstruction.
	- Patient may need oxygen supplementation.

#### **Box 4.3**

Aspiration of small objects like burs, endodontic fles, and reamers may not cause immediate lifethreatening airway obstruction, but retrieval of these rather small and prickly instruments from lungs is a very diffcult task needing bronchoscopy and can result in serious lung infections and damage. Prevention takes priority.

#### **4.5 Anaphylaxis**

Sudden onset, severe form of life-threatening allergic reaction, which can be seen following exposure to an allergen. Remember topical anesthetic gels, chlorhexidine mouth wash, and even contact with latex gloves can trigger anaphylaxis in individuals who are sensitive [8].

Prompt recognition and immediate response are key to success.

#### **Signs and Symptoms:**


#### **Treatment:**

	- Oxygen supplementation at 15 L/min.
	- Keep assessing the airway and provide necessary support.
	- Chlorpheniramine maleate IM or IV.
	- Hydrocortisone sodium succinate IM or IV.
	- Establish Intravenous access.
	- Ringer's lactate solution or 0.9% Normal saline to support circulation.
	- Reassess the need for further adrenaline.

#### **Box 4.4**

Adrenaline is to be administered if there is severe respiratory distress or when there are signs of shock.

#### **Box 4.5**

Adrenaline—Life-saving drug for Anaphylaxis

	- Site: I.M Anterolateral thigh Dosage:

#### **Box 4.6**

#### **Second-line drugs:**

Hydrocortisone sodium succinate: 100 mg Route: IM or Slow IV 12 years and adults: 200 mg IM/IV 6–12 years: 100 mg IM/IV 6 months to 6 years: 50 mg IM/IV Chlorpheniramine Maleate Supply: Chlorpheniramine Maleate 10 mg/1 mL Ampoule Route: IM or IV 12 years and adults: 10 mg IM/IV 6–12 years: 5 mg IM/IV 6 months to 6 years: 2.5 mg IM/IV

#### **4.6 Chest Pain**

Experiencing chest pain in an outpatient offce can be a frightening experience for both the patient and to the attending clinician. Thorough understanding of the pathophysiology of these acute cardiac events is very important for the clinician to stay composed and initiate appropriate measures to prevent mortality. Myocardial infarction may not always have the typical features of chest pain and especially diabetic patients may not have pain. Hence, a high index of suspicion is what is required.

Causes of chest pain:


Hyperventilation is associated with anxiety and often a young person who is quite frightened of the intended treatment, the breathing gets very heavy resulting in decreased carbon dioxide levels in the blood.

#### **4.6.1 Angina**

Transient decrease of oxygen supply to cardiac muscle precipitates pain.

Precipitating factors:

Anxiety, stress, exertion, strong emotions, heavy meal, and extreme weather conditions.

#### **Signs and Symptoms:**

If you are looking for typical symptoms of chest pain, you may miss some cases. List of all possible presentations being:


#### **Management:**


Simple angina should resolve very quickly with rest alone or with sublingual glyceryl trinitrate spray or tablets. In simple angina, the cardiac output is not impaired, and pulse should be regular. In a patient with chest pain, having an irregular pulse, suspect MI.

#### **4.6.2 Myocardial Infarction (Heart Attack)**

Progressive/Sudden ischemia of the cardiac muscle leads to necrosis of cardiac muscle. This can cause cardiac arrest.

#### **Signs and Symptoms:**


#### **Management:**

	- Establish IV access.
	- Give antiemetic Metoclopramide hydrochloride by IV [13].

Adult > 60 kg, dose 10 mg

Small-sized Adult <60 kg, dose 5 mg

– Administer analgesia - Paracetamol by slow IV (Morphine, diamorphine 7 fentanyl, are not easily available in India) [13].

Adult >50 kg, dose 1000 mg in 100 mL Small-sized Adult <50 kg, dose 750 mg in 75 mL When no IV access, alternatively, give Oral Paracetamol 650 mg

	- Watch for signs of cardiac arrest.
	- Start CPR, if cardiac arrest occurs.

#### **Box 4.7**

Drugs for MI:

Glyceryl Trinitrate Aerosol Spray: 400 μg/metered dose

Glyceryl Trinitrate: 300-μg tablets Soluble Aspirin: 300-mg tablets Metoclopromide: 10-mg solution for IV Paracetamol: 1000-mg/100-mL solution for IV Paracetamol: 500-mg tablets Paracetamol 650 mg tablets

#### **4.7 Cardiac Arrest**

Cardiac arrest is a sudden loss of heart function resulting in hypoxic damage to body organs. Lack of oxygen to the brain causes loss of consciousness, victim falls to the ground and stops breathing. Cardiac arrest can occur suddenly with or without any symptoms.

Following cardiac arrest neurons start to die within 4–6 min without oxygen. Chances of survival can be increased by early defbrillation (where indicated) and good-quality Cardiopulmonary Resuscitation, that's instituted quickly and performed with minimal interruptions. Automated External Defbrillators (AED) are increasingly available and these can analyze the rhythm, whether it's shockable or not and can suggest you through the process of CPR by voice commands. In centers where AEDs are not available, CPR is continued until appropriate help arrives. Often, in busy countries like India, this can take quite a considerable amount of time, so hospitals and healthcare establishments should be encouraged to buy AEDs.

Recognition of cardiac arrest:

	- Some people may have a seizure when cardiac arrest occurs as a result of severe cerebral hypoxia.

#### **Box 4.8**

Chest pain in a patient with previous history of stable angina: Urgent transfer to appropriate medical facility is to be done, if the patient feels the pain is unusual or if the pain doesn't resolve with rest and Sublingual Glyceryl Trinitrate.

#### **Box 4.9**

Do not waste time, for example, trying to fnd a vein while the ambulance is waiting! Antiplatelet medication (aspirin) within few minutes of suspecting MI and early thrombolysis by the Physicians can signifcantly reduce the mortality associated.

#### **Management:**

	- CPR can be executed in the dental chair.
	- Second person checks airway, gets ready for ventilations, preferably using a bag valve mask.
	- Nonshockable rhythm observed by AED—continue CPR until signs of life or AED starts analyzing rhythm again [16].
	- Shock advised by AED—Make sure no one touches the patient directly or indirectly—Deliver the shock.

#### **Fig. 4.1** Chain of survival


To improve overall outcome in cardiac arrest patients, it is necessary to follow these four important aspects of care:


The four points are incorporated into this internationally recognized "chain of survival," which is given here (adapted from the Resuscitation Council UK; website: https://www. resus.org.uk/EasysiteWeb/getresource.axd?AssetID=3907& type=Full&servicetype=Attachment) (Fig. 4.1):

#### **Box 4.10**

All healthcare workers should undergo proper training in CPR. Healthcare organizations throughout the world are now insisting on a CPR certifcate. Such a training has to be done on a periodic basis so that the skills are retained. The reader is strongly advised to undergo training periodically and a valid certifcate will prevent you from future litigation if an unfortunate event occurs to one of your patients.

#### **4.8 Hypoglycemia**

Glucose is essential for the effective functioning of neurons. When the glucose levels in blood drop to a very low level, brain function will get affected and if the glucose levels are not restored quickly, permanent neurologic damage can occur within 4–6 min. Hypoglycemia can occur in diabetic patients taking Insulin, who skipped meal, and is also the leading cause of loss of consciousness in children. Hypoglycemia occurs when blood glucose level falls below 70 mg/dL.

#### **Signs and Symptoms:**

	- Nausea and vomiting
	- Hungry
	- Visual disturbances
	- Convulsions
	- Loss of consciousness.

#### **Management** [17]:

Management depends on consciousness level and the ability of the patient to take food orally without the risk of aspiration.

	- 10–20 g of glucose

10 g of glucose in two teaspoons of granulated sugar Two teaspoons of Glucon-D powder contain 15 g of Glucose

	- Check if airway is clear—ABCDE approach
	- Put patient in recovery position
	- Oxygen supplementation at 15 L/min

Arrange for emergency transfer of patient Give 100 mL of 10% dextrose by IV route

Severe cases of hypoglycemia need 50 mL of 50% Dextrose

Higher concentrations of dextrose are thicker solutions, need a larger bore cannula.

Once the patient regains consciousness, give oral glucose and carbohydrate as earlier.

#### **Box 4.11**

Glucagon either by IM or SC route

Dose: Adult—1 mg

Child under 8 years or less than 25 kg should be given 500 μg (0.5 mg)

Keep patient in lateral position to prevent risk of aspiration

#### **4.9 Grand Mal Seizures**

Enquire with patients about how frequently they get seizures and their compliance with medication. Patients with frequent seizure history or patients who are irregular with their medications are more likely to have a seizure while having dental procedures. Provide the treatment in a calm, stress-free environment, avoid any seizure-triggering factors.

#### **Signs and Symptoms:**


#### **Treatment** [18]:

	- Remove all the sharps away
	- Create safe space around a ftting patient
	- Provide cushions like a pillow or blanket
	- Pay particular attention to head
	- Provide reassurance and empathy to the patient
	- Explain what had happened
	- Examine the mouth for any fuids and use suction
	- Examine for any bleeding, lacerations of tongue secondary to biting
	- Place the patient in a recovery position
	- Examine for any other injuries
	- Provide oxygen as required
	- Stay with the patient until the patient is fully recovered
	- Do not give anything orally until the patient is fully conscious, to avoid the risk of aspiration
	- Do not attempt to arouse a patient who is sleeping after a convulsive episode
	- Make arrangements for urgent transfer to appropriate medical center
	- Administer midazolam intravenously [21]
	- Where IV access is not possible:
		- Rectal route can be used effectively, especially in children.
		- Buccal midazolam gel can be instilled into buccal vestibule with the help of a syringe with no needle. Midazolam sprays, which can be used via nasal route, are slowly being available in India.
		- Buccal and nasal routes are increasingly being used and the reader is advised to look up for more up-todate information as suitable formulations are not routinely available in India.

#### **Box 4.12**

Midazolam Dosage:


Child: 0.1–0.2 mg/kg, not to exceed 10 mg in total Nasal Spray: Child: 0.2 mg/kg body weight (Max: 5 mg/nares)

Rectal: Adult and children above 12 years: 10–20 mg, can be repeated once after 10–15 min if needed

Child 2–11 years: 5–10 mg, can be repeated once after 10–15 min

#### **Box 4.13**

Remember generalized tonic-clonic seizures can be seen in:


#### **Box 4.14**

Midazolam is a benzodiazepine that carries the risk of respiratory depression. Patients need close monitoring after drug administration and may need respiratory support.

#### **Box 4.15**

Typical grand mal seizure, in a known epileptic patient, where the seizure has subsided within a couple of minutes, patient can be discharged with the carer, provided all the vital signs are with in normal range. Urgent hospital transfer is indicated in all other epileptic seizures.

### **4.10 Syncope**

Energy demands of the brain are met primarily by oxidation of glucose. A regular and constant supply of glucose and oxygen is essential for brain function. Supply of both glucose and oxygen depends on effective perfusion of the brain. When brain perfusion decreases beyond a critical level, the patient loses consciousness and the balance gets affected and the patient falls.

#### **Signs and Symptoms:**


#### **Management** [22]:


#### **4.11 Other Causes of Loss of Consciousness**

Although syncope is the most common cause of loss of consciousness, the other causes should also be borne in mind, as some of them can be quite serious, such as:


#### **Postural Hypotension:**


#### **Hyperventilation:**

Excessive breathing in an anxiety state or excessive crying resulting in drop of blood CO2 level.


#### **4.12 Conclusion**

Preparedness for emergency is the key and when you are prepared, emergencies are easier to manage. The maxillofacial surgeon should be able to recognize these conditions and initiate appropriate management before professional emergency help is available. More often, maxillofacial surgeon is the lone clinician and is the sole responder in an emergency. It is prudent for the surgeon to know what to do and what not to do to get the best out of the worst scenario or situation.

It is imperative that the maxillofacial surgeons thoroughly understand the pathophysiology and extend their skills to recognize and manage expeditiously and effectively the emergencies that may arise. It is advisable that the contemporary clinicians update their knowledge and skills periodically with proper training courses.

Protocols given here are based on the currently available evidence, keeping in view of the local healthcare systems and access. As protocols are only suggestive, the clinician is strongly advised to use his or her own discretion when dealing with medical emergencies (Table 4.1; Flowchart 4.1).

**Table 4.1** Causes of loss of consciousness and its age distribution


**Flowchart 4.1** Management algorithm for a collapsed patient where the cause of collapse is not known

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

**Part III**

**Anesthesia for Oral and Maxillofacial Surgery**

## **Local Anesthesia in Oral and Maxillofacial Surgery**

Reena Rachel John

#### **5.1 Introduction**

Pain, the dreaded symptom, is an unpleasant sensation that draws the attention of the individual as a whole. Its management has greatly evolved in the feld of dentistry, starting from the leaves of a coca tree to articaine, Comfort Control Syringe (CCS) system, Transcutaneous Electrical Nerve Stimulation (TENS), Computer-Controlled Local Anesthetic Delivery System as well as oral and intravenous sedatives. Apart from all these, local anesthesia (LA) is the favored mode of pain control in the profession. The painless surgery under LA is must; otherwise, endogenous catecholamines are released if there is excessive pain during dental treatment, which can alter the hemodynamic status such as an increase in blood pressure and heart rate and even dysrhythmias [1].

#### **5.1.1 Historical Background**

The frst local anesthetic isolated from the leaves of a coca tree in 1860 by Neiman was cocaine, and it was Karl Koller in 1884 who showed the anesthetic effect of Cocaine. In 1905, Einhorn popularized Procaine as an effective local anesthetic. It was derived from benzoic acid and diethyl amino ethanol. In 1948, the anesthetic property of lignocaine was discovered by Lofgren, and T. Gordh applied it in dental surgery [2].

#### **5.1.2 Defnition**

Local anesthesia is defned as a reversible loss of sensation in the circumscribed area of the body caused by depression of excitation in the nerve endings or inhibition of the conduction process in peripheral nerves [2].

### **5.1.3 Ideal Characteristic of Local Anesthesia**

An ideal local anesthetic must have the following characteristics:


### **5.2 Classifcation** (Tables 5.1 and 5.2)

**Table 5.1** Classifcation of local anesthetic agents: based on chemical structure


R. R. John (\*)

Department of Oral and Maxillofacial Surgery,

**5**

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 61 K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_5

Vinayaka Mission's Sankarachariar Dental College and Hospital, VMRF DU, Salem, India

**Table 5.2** Classifcation of local anesthetic agents: based on duration of action


#### **5.3 Local Anesthetic Agents**

The LA agents have been divided into Esters and Amides groups. The commonly used Amides are Lidocaine, Articaine, and Bupivacain [2].

#### **5.3.1 Lidocaine (Lignocaine)**

Lofgren in 1943 introduced the prototype amide local anesthetic [2], i.e., Lidocaine.

The other similar names are xylocaine, octocaine, dentocaine. Chemically, it is Diethyl 2, 6 dimethyl acetanilide. The maximum recommended dosage for Lignocaine with vasoconstrictor is 7 mg/kg not exceeding 500 mg and without vasoconstrictor is 4.4 mg/kg not exceeding 300 mg. Its onset of action is 2–3 min and duration of action with vasoconstrictor is 45–75 min, without vasoconstrictor is less than 30 min. Its contraindications include Ehlers Danlos syndrome and Attention-defcit hyperactive syndrome. Lignocaine is available in the form of jelly, spray, patches, and ointments. The toxicity arises from inadvertent intravascular administration or from overdose.

Recently, Howlader et al. [3] suggested open reduction and internal fxation (ORIF) of isolated subcondylar fractures under local anesthesia by using 2% lidocaine with 1:200,000 epinephrine for mandibular nerve block and superior cervical plexus blocks (SCPB).

To anesthetize the cutaneous branches of SCP (lesser occipital, greater auricular, transverse cervical, and supraclavicular nerve), the solution is deposited at the midpoint of the posterior border of sternocleidomastoid muscle border, as well as inferior and superior to that point subcutaneously creating a feld block.

The anesthetic agent selection should be based on three main clinical considerations: anesthetic potency and latency, onset, and duration. The composition of the local anesthetic solution is shown in Table 5.3.

R. R. John

**Table 5.3** Composition of local anaesthetic solution (Lignocaine with Adrenaline)


#### **5.3.2 Bupivacaine**

Its chemical name is 1 butyl-2,6piperoloxylidine hydrochloride.

It is four times more potent than prilocaine, lidocaine, and mepivacaine. It is less toxic than lidocaine and mepivacaine and it is metabolized in the liver by amidases and excretion via kidney 16% unchanged. Its onset of action is similar to lidocaine, mepivacaine, and prilocaine. Effective dental concentration is 0.5% and anesthetic half-life is 2.5 h.

Maximum recommended dose is 1.3 mg/kg body wt to a maximum of 90 mg. Because of its long duration of action, it is advisable for use in lengthy surgical procedure and the management of postoperative pain. Hence, the patient's requirement for postoperative opioid analgesics is lessened when bupivacaine is used. Bupivacaine is not recommended in young patients as the risk of self-mutilation is increased.

The duration of soft-tissue anesthesia has been consistently shown to be longer than with lidocaine [4] and thereby reducing postoperative pain experience [5].

#### **5.3.3 Articaine**

Its chemical structure is 3-N Propylaminoproprionylamino 2-Carbomethoxy 4-Methylthiophene hydrochloride.

The potency of Articaine is 1.5 times more than lignocaine and 1.9 times than procaine. Its onset of action when used with vasoconstrictor is 1–2 min. Half-life is approximately 21 min and it is metabolized to pharmacologically inactive metabolite called articaine acid glucoronide. Since it is rapidly biotransformed to its inactive metabolite, it is a safe local anesthetic agent. It is excreted via kidney

**Table 5.4** Maximum recommended dose of common Local Anesthetic used


unchanged (5–10%) and as metabolite (90%). The maximum recommended dosage for articaine is 0.8 mg/kg body weight.

Contraindications for the use of articaine are Idiopathic or congenital methemoglobinuria, hemoglobinopathies, hypoxia, and in patients with cardio-respiratory failures. Prolonged paraesthesia has been reported as a complication following inferior alveolar nerve block (IANB) [6].

Articaine with epinephrine is the best choice to improve anesthesia in both infamed and in uninfamed tissues with good results, and more effective anesthesia for longer duration can be achieved [7]. Table 5.4 shows maximum recommended dose of commonly used LA.

#### **5.4 Vasoconstrictors**

Importance of vasoconstrictors in local anesthetic solution include


Most commonly used vasoconstrictors are epinephrine, norepinephrine, levonordefrin hydrochloride, phenylephrine hydrochloride.

#### **5.4.1 Dilution of Vasoconstrictor**

The explanation of 1:1000 vasoconstrictor concentration is that 1 g/1000 mg of solute is present in 1000 ml of the solution, which means 1 mg of solute in 1 ml of solution. In the local anesthetic solution, the concentration of vasoconstrictor is less. The concentrations used are 1:80,000 or 1:100,000 or 1:200,000. The concentration of 1:100,000 of the vasoconstrictor would contain 1000 mg in 100,000 ml of the solution. Therefore, 1 ml of 1:100,000 concentration would contain 0.01 mg in 1 ml.

**Table 5.5** Quantity of vasoconstrictor with varying dilutions


The absorption of vasoconstrictors is dose dependent and may last from minutes to half an hour. The patients with cardiovascular compromise are at increased risk with endogenously released epinephrine in response to stress rather than the epinephrine, which is injected with the local anesthetic (Table 5.5).

#### **5.5 Causes of Failure of LA**


#### **5.6 LA Toxicity and Antidote for Toxicity**

Symptoms, which refect toxicity from the administration of local anesthetic solution, may range from mild cutaneous reactions to severe life-threatening anaphylactic reactions. There are a variety of methods and drugs to treat these reactions symptomatically. However, the reversal of toxicity, including damage to vital organs such as the heart and brain, is still less understood. A clinically effcient antidote for a complete reversal of toxicity is still beyond our grasp currently.

#### **5.6.1 Reversal of Cardiomyotoxicity**

Intravenous lipid emulsion (IVLE) is being reported as a rescue measure for LA toxicity. This has been studied and proven in both animal models and in limited human trials with successful resuscitation outcomes. The lipid emulsion acts on the plasma and tissue and extracts the lipophilic anesthetic molecules, thereby reversing their inhibitory myocardial effects. Bolus doses of 1.2–2 ml/kg followed by continuous infusion of 0.25–0.5 ml/kg/min are currently advocated for adequate effcacy. This drug needs to be used judiciously as optimal dosages have not been established and the risks of overdosage are not clearly understood.

#### **5.7 Reversal of Soft-Tissue Anesthesia**

The duration of soft-tissue anesthesia often exceeds that of pulpal or bony anesthesia. This is an important reason for the occurrence of undesirable events like accidental lip or tongue biting, diffculties in speaking, eating, or drinking liquids, etc. Various drugs have been studied to decrease the postoperative duration of anesthesia. Of the various drugs tried clinically, phentolamine is one drug, which has demonstrated appreciable clinical effcacy.

Phentolamine is a nonselective alpha-adrenergic antagonist that is reversible. Its main action is vasodilatation. It has been used effectively for controlling hypertensive emergencies, especially in pheochromocytomas. In dental practice, Phentolamine in the form of phentolamine mesylate injections has been used as a reversal agent against LA by reversing the action of vasoconstrictors in the LA solution and expedites the metabolism of the LA molecules. The recommended dose for phentolamine is the administration of 1.8 ml of the solution containing 0.4 mg of phentolamine mesylate immediately after treatment.

#### **5.8 Plain Local Anesthetic (Without Epinephrine)**

It is preferred for patients having comorbidities such as circulatory disorder to avoid complications and adverse systemic effects of vasoconstrictors [8]. Lip laceration is one of the common cases, which are attended to by a maxillofacial surgeon in the emergency department for suturing. Localized blanching caused by the use of local anesthetic with adrenalin at the lacerated wound causes diffculty in locating the exact demarcation between skin, white roll, and lip. Therefore, LA without epinephrine is preferred in such cases before suturing [9].

#### **5.9 Topical Local Anesthetic Agent**

The solution used for this purpose is 5% Lignocaine, 10% Lignocaine, combination of 2.5% lignocaine and 2.5% prilocaine [10]. They are indicated in patients [11, 12]


In suture and staple removal

#### **5.10 Surface Anesthesia**

The form of drug used to obtain this includes ointment, gel, viscous, cream, spray, etc. Topical application of these forms can produce anesthesia on the surface, particularly of the oral mucosa.

This is used often, before an actual injection for L.A, at the site of injection, in order to reduce the pain of the needle prick itself. It can also be used to obtund pain in situations where the oral mucosa is breached, as in an ulcer in the oral mucosa. The gel may also be used to anesthetize the surface mucosa, e.g., nasal, pharyngeal, etc., before a diagnostic endoscopy.

The concentration of a local anesthetic applied topically is typically greater than the same drug administered by injection. Drugs that are commonly employed in topical L.A formulations are Benzocaine and Lidocaine.

EMLA, which is a eutectic mixture of local anesthetic agents, lignocaine, & prilocaine in the ratio 1:1 by weight, has been found to be a very useful topical agent to be applied on the skin, before painful procedures like injection, venipuncture, etc. and is used extensively in children. This particular cream, which is oil-in-water emulsion, may also be used for surface anesthesia of the oral mucosa for purposes listed earlier.

#### **5.11 Methods of Local Anesthetic Administration**

There are major three different types of methods:


In local infltration, deposition of the local anesthetic solution in the area of the surgery to anesthetize small terminal nerve endings. Field block involves the deposition of anesthetic solution near the large terminal nerve branches to prevent the passage of impulses from teeth to the central nervous system. In nerve block, local anesthesia is deposited away from the site of surgery, but close to the main nerve trunk.

Different techniques for mandibular nerve block anesthesia have been published, including the mental/incisive nerve block [13–15].

	- standard approach for mandibular anteriors and soft tissue
	- anterior approach
	- extraoral approach

#### 5 Local Anesthesia in Oral and Maxillofacial Surgery


Different maxillary nerve block techniques have been described.

	- intraoral approach (bicuspid approach)
	- Bisecting approach (central incisor)
	- extraoral approach
	- nasal approach (1969)
	- High tuberosity approach
	- Greater palatine canal approach
	- nasal approach
	- lateral extraoral approach
	- suprazygomatic extraoral approach extraoral approach
	- anterior-lateral extraoral approach.

#### **5.11.1 Percentage of Blood Vessel Penetration During IANB**

During IANB, the intravenous injection of local anesthetic is very common. Frangiskos F et al. [16], in their study, found positive aspiration (the tip of the needle is in the blood vessel) 20% times. The positive aspiration was more commonly seen in young patient's age ranging from 9 to 19 years. To avoid systemic complications while giving local anesthesia, aspiration is must in each and every case.

### **5.11.2 Controversy in the Use of Bilateral IANB and Lingual Nerve Block** [17]

Has bilateral IAN and Lingual nerve block been given? Some surgeons recommend, while some do not, but there are no published data available regarding its contraindications. The common complications associated with its use are


Many authors advocated the use of sodium bicarbonate in addition to the lignocaine solution to reduce the duration of onset of anesthesia, and it is very effective in reducing pain during the injection. Sodium bicarbonate ions also nonspecifcally reduce the safety margin for nerve conduction and it has a direct action on the binding of Local anesthetic to the sodium channel [19–21].

#### **5.12 Techniques**

#### **5.12.1 Inferior Alveolar Nerve Block (***Also Known as* **Mandibular Nerve Block) [Along with Lingual & Long Buccal Nerve Blocks]**

This is the single most important nerve block, whose technique needs to be mastered. With this, we can anesthetize the whole of the mandibular soft and hard tissues, including the cheek, and many procedures in this region can be carried out.

Secondly unlike in the maxilla, infltration techniques do not provide adequate anesthesia to the hard tissue in the mandible, particularly the teeth. This is due to the dense cortical bone in the mandible, in contrast to the porous maxillary bone, where a paraperiosteal deposition of the solution can allow the solution to diffuse through the bone to the periapical region easily and cause anesthesia of the teeth and their supporting structures.

#### **5.12.2 Technique**

This description is for injection on the right side of the patient and for a right-handed operator. The surgeon is on the right side of the patient, in front of the patient. The patient is asked to open the mouth wide.

With the left hand, the operator palpates the posterior buccal sulcus, runs the index fnger posteriorly to feel the external oblique ridge and the anterior border of the coronoid process. As the fnger proceeds upwards, palpate the coronoid process up and down to determine the deepest point on its anterior border. This is the coronoid notch. [This is a very important landmark because this determines the vertical height at which the needle should be inserted, the reason being the Mandibular foramen on the medial aspect of the ramus where we want the needle to reach is in direct line with the coronoid notch] Fig. 5.1.

Once the coronoid notch is palpated with the pulp of the index fnger, the fnger is rotated such that the nail faces medially. At the same time, the fnger retracts the soft tissue

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 5.1** Dry mandible showing the position of needle and the coronoid notch

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 5.2** Picture showing needle insertion position from the soft tissue for IAN block

to reveal a depression called the pterygo mandibular depression, which is medial to the fnger between the fnger and the pterygo Mandibular raphe (Fig. 5.2).

Now the needle with solution in the syringe is taken in the right hand and is introduced into the mouth from the opposite side (i.e., left side) corner of the mouth/premolar area.

The syringe and needle are kept parallel to the Mandibular occlusal plane and are introduced into the pterygo temporal depression at the same height as the nail of the index fnger (on the coronoid notch). The needle is advanced slowly in the soft tissue till the needle strikes the bone and resistance is felt. Now the needle is in the pterygo mandibular space bounded laterally by the medial surface of the ramus of the mandible and it is just above the lingula in the area of the opening of the mandibular foramen.

The syringe is aspirated and 1 ml of the solution is deposited. This will anesthetize the inferior alveolar nerve as it enters the mandible. Now, the needle with the syringe is swung on to the corner of the mouth on the same side, i.e., right, and is slowly withdrawn after about half the length is inserted and 0.5–0.8 ml of the solution is deposited here. This will take care of the lingual nerve, which is anteromedial to the inferior alveolar nerve.

Now the needle is withdrawn completely out of the soft tissue and is reinserted into the cheek, posterior to the last molar teeth at the level of the occlusal plane of the mandibular teeth for a short distance. After aspiration, the remaining 0.5 ml of the solution is deposited. This anesthetizes the long buccal nerve [for the left-sided block, the surgeon is slightly behind the patient on the right side with the left hand coming around].

This classical Mandibular Nerve block of inferior alveolar nerve with lingual & long buccal is done together if the mandibular molars and their adjoining soft tissues need to be anaesthetized. The reason being the pulp and the periodontium of these teeth are supplied by the inferior alveolar nerve. The lingual gingiva is supplied by the lingual nerve and the buccal gingiva by the long buccal nerve.

#### **5.12.3 Areas Anesthetized by This Block**

	- (a) All mandibular teeth and the bone surrounding them.
	- (b) The buccal gingiva in relation to the Mandibular anterior and premolar teeth.
	- (c) Lower lip on the same half up to the midline.
	- (a) The lingual gingiva of the Mandibular teeth along with the lingual Mandibular mucosa.
	- (b) The Anterior 2/3rd of the tongue on the same side.
	- (a) The cheek mucosa.
	- (b) Buccal gingiva and mandibular mucosa in relation to the molar teeth.

#### **5.12.4 Signs and Symptoms of Anesthesia**

It usually takes about 3–5 min before adequate depth of anesthesia is obtained after any injection. In other words, although symptoms of anesthesia may be felt almost instantly after the injection, for the patient to feel no pain during the procedure a wait of at least 5 min is needed.

It has been conventional to confrm the anesthesia obtained with two parameters:


Subjective symptoms may or may not be present with certain nerve blocks, e.g., nasopalatine block. However with the classical inferior alveolar/mental nerve block, a *tingling and numbness* on one half of the lip (same side) will be felt. There will be an area of sharp demarcation between the numb side of the lip and the normal side at the midline. The tingling or numbness will start instantly to become heavy in about 3–5 min. Similar sensation of numbness will be felt on the same side of the tongue particularly the tip as a result of the lingual nerve block. There may be no symptoms of numbness felt by the patients in the other anaesthetized areas, e.g., the gingiva, teeth, or the cheek.

The objective sign as elicited by the surgeon is more reliable and may be the only means of ascertaining anesthesia in the absence of subjective symptoms. The objective sign of anesthesia is *lack of pain in the area anesthetized when stimulus is applied* with a blunt instrument, e.g., the end of a periosteal elevator. [It should be noted from the earlier discussion that the patient might feel the pressure of the instrument and an apprehensive patient might occasionally interpret this as pain.]

In checking for anesthesia of the inferior alveolar nerve, the blunt instrument must be applied on the buccal gingiva anterior to the mental foramen, because the lack of sensation in the posterior buccal soft tissue indicates a successful long buccal nerve and not inferior alveolar nerve block. The same blunt instrument must be applied in the gingival sulcus on the lingual side of the tooth to be extracted for lingual nerve anesthesia. The same can be done to check the buccal nerve anesthesia.

#### **5.12.5 Complications** (Table 5.6)

These were discussed very briefy as local complications of L.A in the earlier section. Specifc complications after an Inferior Alveolar Nerve block include:




#### **5.12.5.1 Failure to Obtain Anesthesia**

It is the most common problem and usually due to the wrong technique. Repeating the block employing the right technique is usually the solution. However, this might be encountered in two other situations.


#### **5.12.5.2 Hematoma Formation**

This may occur within the pterygo mandibular space as a result of bleeding induced by the needle prick. It may be a rare problem. The patient might have pain, swelling, & diffculty in opening the mouth. The treatment is symptomatic and possibly prophylactic antibiotic cover. It will resolve spontaneously.

#### **5.12.5.3 Transient Facial Nerve Palsy**

May occasionally occur as a result of a faulty technique where the needle is inserted farther posteriorly into the substance of the parotid gland (in this situation, the needle would have failed to encounter bony resistance) and paralyzes the facial nerve.

The patient will have typical signs of ipsilateral facial nerve palsy/weakness, which includes diffculty in closing the eye, absence of wrinkles on the forehead, and drooping of the corner of the mouth ipsilaterally with a possible asymmetry. This effect will be transient, till such time the local anesthetic effect persists (about 1–1½ h) and the patient needs to be reassured.

#### **5.12.5.4 Trismus**

Is a relatively more common complication and will be seen usually postoperatively. It could be due to a variety of causes, including:


Most of the time it resolves spontaneously. But on occasion, this will require anti-infammatory analgesics, muscle relaxants, and vigorous physiotherapy to overcome the problem. Wherever an infection is suspected, a suitable antibiotic cover may also be needed.

#### **5.12.5.5 Accidental Breakage of the Needle**

Occurring within the tissues of the pterygo mandibular space, this is a very rare complication today where we use disposable needles for one use only. But when this happens, a radiographic guided exploration and removal of the broken piece may be needed. Gerbino G et al. [22] advocated use of brain LAB vector vision neuronavigation system for the retrieval of broken needle. This Intraoperative navigation system is very helpful in locating the broken needle fragment.

#### **5.13 Vazirani–Akinosi (VA) Versus Inferior Alveolar Nerve Block**

The closed mouth VA technique to anesthetize the IAN, lingual, and long buccal nerve simultaneously was described in 1977 [23]. VA is used only secondarily to conventional IAN block.

#### **5.13.1 Indications for VA** [24]


The percentage of Positive aspiration is much higher with IAN block in comparison to VA. This is because of the close proximity of the inferior alveolar artery, which enters the mandibular foramen just behind the nerve [25]. To avoid frequent aspiration, many surgeons prefer VA technique in normal patients also.

#### **5.13.2 Akinosi–Vazirani Technique (Closed-Mouth Technique)**

A 25-gauge long needle is used. The operator is in front of the patient on the right side (right-handed operator) for both sides on the patient.

With the left index fnger or thumb, the coronoid notch is palpated and the soft tissues on the medial aspect of the ramus are pushed laterally. The needle is held parallel to the maxillary occlusal plane on the same side of the injection and is inserted adjacent to the maxillary third molar into the soft tissue overlying the medial border of the ramus, just adjacent to the maxillary tuberosity. This is now advanced posteriorly & slightly laterally. The bevel of the needle is away from the mandibular ramus and in an average-sized adult the needle is inserted about 25 mm into the tissue. At this point, the tip of the needle will be in the middle of the pterygo mandibular space close to the branches of the mandibular nerve. After aspiration, the LA solution is injected.

The areas anesthetized, signs and symptoms of anesthesia are similar to the open-mouth technique of mandibular nerve block.

Another viable alternative to the VA block is the technique of Gow-Gates described in 1973. In the Gow-Gates technique, anesthesia is administered more proximally, at the neck of the condyle and relies on extraoral landmark [26].

#### **5.13.3 Technique**

A 25-gauge long needle is used. The operator stands in front of the patient. It is very essential for the patient to extend his neck & open the mouth as wide as possible. Here the needle is inserted into the mucosa medial to the mandibular ramus on a line parallel to a line drawn from the intertragic notch to the corner of the mouth—just distal to the maxillary second molar. The needle is inserted from the corner of the mouth on the opposite side. The height of insertion is just at the level of the mesiolingual cusp of the maxillary second molar. Slowly advance the needle till the bone is contacted. (The needle here is in contact with the neck of the condyle. The position the patient is asked to assume, i.e., extend neck & open mouth wide, is to facilitate a more frontal position of the condyle closer to the mandibular nerve trunk). The average depth of insertion is about 25 mm. Aspirate & inject 2 ml of the solution slowly. Unlike with the classical method, injection is at one site only in this technique. This anesthetizes the inferior alveolar, lingual, long buccal branches of the mandibular here with similar effect as the classical block (Fig. 5.3a, b).

#### **5.14 Mental/Incisive Nerve Block**

These are two very similar blocks except that in a mental block the solution is deposited around the mental nerve as it exits the mandible at the mental foramen, whereas for an incisive nerve block, the solution is injected into the mandible through the mental foramen. This blocks the incisive nerve, which is the continuation of the inferior alveolar nerve anteriorly, up to the midline.

#### **5.14.1 Technique**

This may be carried out with the operator standing in front of the patient (can also be done easily with the operator standing behind).

With the left-hand thumb or index fnger, palpate the mucobuccal fold on the mandible starting in the molar region moving anteriorly when depression will be felt. This is usually in relation to the apex of the premolar teeth where the mental foramen is present. The needle is now directed vertically to be inserted into this area with the bevel facing the bone. With the mental nerve block, the solution is deposited in the soft tissues, whereas for the incisive the needle is inserted into the foramen for a short distance before injection.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 5.3** (**a**, **b**) Position of needle from medial and lateral aspect in case of closed-mouth technique

#### **5.14.2 Areas Anesthetized**


#### **5.14.3 Signs and Symptoms**


#### **5.15 Nerve Blocks in the Maxilla**

As already mentioned, in maxilla buccal & palatal infltration techniques are often followed because they are effective, particularly if the surgical area is limited, e.g., extraction of a single tooth. However nerve blocks are useful at times, particularly when anesthesia of a larger area is sought.

#### **5.15.1 Posterior Superior Alveolar Nerve Block Technique**

The position of the operator is on the front of the patient for both sides, on the right side, for a right-handed operator.

Palpate the maxillary mucobuccal fold after asking the patient to open mouth partially and retracting the buccal soft tissue with the index fnger of the left hand. Insert the needle (25/27 gauge— 20-mm length) into the height of the mucobuccal fold opposite the upper second (second) molar tooth. Advance the needle in inward, upward, backward direction with the needle at 45° angle to the maxillary plane for about 10–15 mm. The tip of the needle will now be close to the entry of the posterior superior alveolar nerve into the maxilla on its posterior surface. Inject 1–1.5 ml of the solution after aspiration (Fig. 5.4).

#### **5.15.1.1 Areas Anesthetized**


Hence, this is a nerve block, which may be used if multiple extractions of molar teeth have to be done in the maxilla or any other procedure in this area.

#### **5.15.1.2 Signs and Symptoms**

*Subjective*: The patient usually will not feel any tingling or numbness in this case.

*Objective*: Lack of pain on probing with the blunt instrument as with any other local anesthetic injection.

*Complications*: Most common problem is a swiftly developing hematoma particularly if the needle goes too far distally into the area of the pterygoid venous plexus.

As in earlier instances, pressure needs to be applied in this case, on the face above the area where the swelling is developing. The sudden swelling can be alarming but is of little consequence once the application of pressure stops fows.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 5.4** Needle insertion position in posterior superior alveolar nerve block

Once again, reassurance to the patient is needed. Prophylactic antibiotics to prevent secondary infection of the hematoma may be considered.

#### **5.15.2 Infraorbital Nerve Block [Also Anterior and Middle Superior Nerve Blocks]**

#### **5.15.2.1 Technique**

The operator (right handed) is on the right side of the patient for both sides, i.e., left & right.

With the left index fnger, the infraorbital rim on the face is palpated. A notch is felt on the medial third of this region, the fnger is now slid down to feel for depression below this notch on the anterior surface of the maxilla. This is the position of the infraorbital foramen. With the left index fnger over the infraorbital foramen, the cheek is retracted with the thumb and a 25-gauge needle is inserted intraorally into the height of the mucobuccal fold opposite the frst premolar with the bevel of the needle directed toward the bone and the needle being parallel to the long axis of the tooth. The needle is advanced until gentle bone contact is made, and this will be the upper rim of the infraorbital foramen.

Aspirate and inject about 1–1.5 ml of the solution. As the solution is deposited, frm pressure is applied over the infraorbital foramen by the left-hand index fnger so as to facilitate entry of the solution into the infraorbital canal through the foramen (Fig. 5.5a, b).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 5.5** (**a**, **b**) Position of needle insertion and target point in dry skull in Infraorbital nerve block

#### **5.15.2.2 Areas Anesthetized**


#### **5.15.2.3 Signs and Symptoms of Anesthesia**


*Complication*: Are few. Rarely a hematoma may develop.

#### **5.15.3 Palatal Anesthesia**

Injection into the palatal tissues, whether an infltration or a nerve block, is the most painful. The reason is the palatal mucoperiostem is tightly adherent to the bone and there is no easy space for the solution to fow. This also makes the process of injection diffcult as often there is backfow due to the resistance offered.

Most often, particularly when a single tooth is involved, infltration anesthesia is preferred in the palate. However, two nerve blocks are often used particularly when a larger area is involved


#### **5.15.3.1 Greater Palatine Nerve Block**

*Technique*: The greater palatine foramen in the adult is usually present on the palatal side of the second molar tooth at the junction of the alveolus and the horizontal palatine bone. (This may be palpated as a depression in this area but need not be done for the purpose of the nerve block.)

A 25/27-gauge short needle is inserted from the opposite side with the operator standing in front (for both sides of the patient) into the area palatal to the second molar at the junction of the alveolus & the palatine bone (Fig. 5.6a, b). A little solution is deposited (0.1–0.2 ml) at the point of entry and

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 5.6** (**a**, **b**) Intraoral and in dry skull showing insertion of needle in greater palatine nerve block

the needle is advanced into the foramen for a variable distance (0.5–0.7 cm) and the rest, about 0.8 ml is deposited. As *usual, always aspirate* before depositing any solution.

*Areas Anesthetized*: The palatal gingiva of the maxillary teeth till the second premolar on the same side as well as the palatal mucosa & bone on the same side till the premolar region.

#### **Signs and Symptoms of Anesthesia**

*Subjective*: May not always be there. However, numbness in the posterior hard palate mucosa may be present.

*Objective*: Confrmation of anesthesia is always by lack of pain in the area and tested by probing with a blunt instrument.

#### **5.15.3.2 Nasopalatine Nerve Block**

*Technique*: Operator in front with the patient mouth wide open, a 25/27 gauge needle is inserted into the palate just lateral to the incisive papilla. A small amount 0.1–0.2 ml of the solution is injected after aspiration. Now the needle is advanced further into the incisive foramen for a distance of about 0.5–0.75 cm and 1 ml of the solution is deposited as always after aspiration.

*Areas Anesthetized*: Probably the only nerve block, which anesthetizes bilaterally symmetrical areas and hence there is no separate right- & left-sided blocks. The palatal gingiva of the anterior teeth up to the frst premolar on either side as well as the palatal mucosa and bone in the same anterior region.

#### **Signs and Symptoms**

*Subjective*: May be variable if present there is numbness of the anterior palate.

*Objective*: lack of pain in the anesthetized area on blunt probing.

The various nerve blocks discussed so far are the commonly used techniques. Usually this set of techniques is suffcient for all requirements of local anesthesia in the oral cavity. There are a number of alternative techniques, intraoral and extraoral, which are described in literature and may be popular in some parts of the world. However, a couple of them will be discussed here because they may have a specifc indication or may be a popular technique.

#### **5.16 Regional Blocks in Oral and Maxillofacial Surgery**

Regional blocks are fast becoming popular in providing not only local anesthetic support for performing surgical procedures of the head and neck, but also as a method for perioperative pain control in the form of pre-emptive anesthetic techniques.

This section focuses on a few regional blocks, which can be added to the armamentarium of today's maxillofacial surgeon.


#### **5.16.1 Maxillary Nerve Block**

There are numerous techniques for achieving total maxillary nerve anesthesia for dental and maxillofacial surgical procedures. These may be divided into intraoral and extraoral methods [27].

The intraoral techniques include:


*The extraoral technique* [28, 29]:

It involves a subzygomatic, technique. The clinical landmarks include the area below the zygomatic arch anterior to the articular eminence. This corresponds to the region above the midpoint of the sigmoid notch of the mandible. A 25-gauge 90-mm-long spinal needle is preferred for this method; the needle is inserted to a depth of about 45 mm till it contacts the lateral side of the lateral pterygoid plate. The needle is then withdrawn half-way and then angulated 15° in the forward and upward directions, which lead it to the region of the superior aspect of the ptm fssure, which corresponds to the exit of the maxillary nerve from the foramen rotundum across the ptm fssure. After negative aspiration, a volume of 2 ml is injected into the space, and the needle is withdrawn (Fig. 5.7).

#### **5.16.2 Mandibular Nerve Block**

The extraoral technique for the mandibular nerve block is very similar to the maxillary nerve block [30].

*Technique*—The surface landmarks and point of penetration for the block are the same and so is the armamentarium. The needle after penetrating the skin is advanced to

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 5.7** Representing pathway of needle in extraoral maxillary nerve block

contact the lateral pterygoid plate as described earlier, following which the needle is withdrawn half way and turned posteriorly by 15° to the same depth of 45 mm. This area corresponds to the region just caudal to the foramen ovale through which the mandibular nerve trunk exits the skull base. After negative aspiration, a volume of 2.5–3 ml is injected to anesthetize the mandibular nerve.

The extraoral mandibular nerve block with suprazygomatic access can be safely and effciently used with this unique approach for the mandibular nerve block to get relief in pain and Trismus. After local infltration, an 18-gauge insulated and stimulating cannula is inserted into the retrozygomatic space just above the zygomatic arch and directed to the angle of mandible with medial and posterior inclination (Fig. 5.8) [31].

#### **5.16.3 Greater Auricular Nerve Block**

This nerve block is performed as an extraoral technique and provides good surface anesthesia to the periauricular skin and skin over the angle of the mandible [32].

*Technique*—The landmarks used for this technique include the cricoid cartilage and the posterior border of the sternocleidomastoid muscle. With the patient supine or semisupine, a line is drawn from the cricoid cartilage to

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 5.8** Showing position of needle insertion in extraoral mandibular nerve block

intersect the posterior border of the sternomastoid muscle. This corresponds to the area where the superfcial branches of the cervical plexus emerge from under the sternomastoid muscle, wrapping around the posterior border. A small subcutaneous injection of local anesthetic solution (around 2 ml) will anesthetize the greater auricular nerve and its area of distribution (Fig. 5.9).

#### **5.16.4 Glossopharyngeal Nerve Block**

The utility of the glossopharyngeal block has been studied in indications such as:


*Technique*—A 25-gauge, 1 inch needle is chosen. The landmark for penetration is the base of the anterior tonsillar

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 5.9** Showing position of needle for greater auricular nerve block

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 5.10** Target area for glossopharyngeal nerve block

pillar lateral to the base of the tongue. The syringe is positioned with the barrel near the maxillary premolar of the contralateral side with the needle facing the base of the anterior tonsillar pillar. The tongue is retracted medially to provide good visualization of the involved site. The needle is then made to pierce the mucosa and advance by 5 mm. This corresponds to the target site for the glossopharyngeal nerve in the submucosal space. After judicious aspiration, if found negative, a volume of 3 ml of anesthetic solution (2% lignocaine) is administered to block the nerve trunk (Fig. 5.10).

#### R. R. John

#### **5.16.5 Sphenopalatine Ganglion Block**

Indications for sphenopalatine ganglion block include:


*Technique*—There are numerous techniques for the administration of sphenopalatine block, but the most commonly followed methods are the greater palatine approach and the transmucosal approach in the posterior aspect of the middle meatus. The greater palatine approach is the same as the maxillary nerve block via the greater palatine canal, which simultaneously blocks the sphenopalatine ganglion as well. The transmucosal method, which is most commonly followed, maybe done blind or using endoscopic guidance. A cotton pledget on a long application stick is dipped in anesthetic solution or gel and is advanced transnasally to the posterior aspect of the middle turbinate to reach the end of the middle meatus. This corresponds to the level of the sphenopalatine ganglion, which is a very superfcial structure. The local anesthetic gel is then deposited, which produces anesthesia through transmucosal perfusion. Another recent technique involves the submucosal injection of the anesthetic solution into the posterior aspect of the middle meatus for achieving the block (Fig. 5.11) [37].

#### **5.17 Recent Advances in Local Anesthesia**

Research is ongoing to fnd newer modalities of pain management. In order to administer local anesthesia with less pain and adverse effects, newer technologies have been developed. Some of them are:

#### **5.17.1 Vibrotactile Devices**

This device is based on the Gate Control theory, which proposes that pain during injection can be decreased by simultaneous stimulation of nerve fbers by vibration.

#### **5.17.1.1 Vibraject** [38]

An attachment, which is battery operated, is snapped on to the barrel to deliver strong vibrations, which is felt by the patient and therefore reducing the perception of pain.

#### **5.17.1.2 Dental Vibe** [39]

It is a handheld device, which delivers pulsed percussive oscillations to the site of injection, thereby closing the pain

©Association of Oral and Maxillofacial Surgeons of India

gate. It does not have a cord and it can be recharged. Dental vibe signifcantly lowered the self-reported pain during local anesthesia injections compared to a conventional approach.

#### **5.17.1.3 Accupal**

It is a cordless device, which shuts the pain gate by preconditioning the site of injection by pressure and vibration. To energize the dental tissue in and around the site to be punctured by the needle, Accupal incorporates the "Pain Gate theory" [40].

### **5.17.2 C-CLAD (Computer-Controlled Local Anesthetic Delivery)**

With this device, there is a controlled delivery of the anesthetic and hence reduction of pain during injection. With this device, we can slowly administer anesthesia and control the injection speed [41].

#### **Advantages of C-CLAD device**

Higher success rates for single tooth anesthesia. The absence of pain especially in pediatric patient with disruptive behavior. More effective than a traditional syringe.

**Disadvantage**—Diffculty in locating the precise site for needle placement.

*C-CLAD* technology led to the development of an instrument for medical and dental injections capable of controlling all variables of subcutaneous injection event.

#### **5.17.3 Compu-Flo**

Allows instantaneous real-time measurement of fuid exit pressure at the tip of the needle. This approach to fuid exit pressure at the tip of the needle is called dynamic pressuresensing technology (DPS) technology.

#### **5.17.4 STA—single tooth anesthesia**

More predictable, reliable, comfortable anesthesia than highpressure mechanical syringe. The system incorporates the safety of using dynamic pressure-sensing technology allowing low-pressure administration of local anesthetic drugs. All patients receiving PDL with STA device reported subjective pain responses of minimal or no pain.

#### **5.17.5 Jet Injection**

The principle of Jet injection is that the mechanical energy is used to force a thin column of the local anesthetic solution through a small opening into the soft tissue under pressure without causing tissue damage. There is less or no pain during this procedure [42].

#### **5.17.6 MED-JET H III**

Local anesthetic solution in extremely small amount is administered under pressure through an orifce seven times smaller than the smallest available.

#### **5.17.7 Safety Dental Syringes** [43]

The protective sheath over the needle prevents accidental needle stick injury.

#### **Ultrasafety Plus XL Syringe**

The plunger, which is autoclavable and reusable, has a sterile disposable protective shield. It does not have to be disassembled prior to disposal.

#### **Ultrasafe Syringe**

Transparent disposable syringe with retractable needle sheath is helpful in aspiration and helps in seeing the aspirated contents in the syringe barrel.

#### **Hyposafety Syringe**

Disposable syringe and needle, which is translucent with a retractable needle into the barrel. Hence, less chance of needle stick injury. The main disadvantage is that the needle cannot be re-exposed to readminister the remaining solution.

#### **REV VAC Safety Syringe**

It is similar to the standard conventional syringe, the difference being that when the plunger reaches the bottom after all the medicine has been administered, further push on the plunger will cause breakage of the needle, which retracts into the plunger. It can be used only once.

#### **5.17.8 Devices for Intraosseous Anesthesia** [44]

#### **Stabident**

This device can be used with the armamentarium that is available in the clinic to administer the anesthetic solution. The main disadvantage is that inaccessible areas cannot be anesthetized with this equipment.

#### **X-Tip**

It is a single-step method. An initial drill is placed, which allows entry and withdrawal in one step during administration.

#### **5.18 Conclusion**

Pain is always a deterrent to seek treatment and hence local anesthesia is a boon to all clinicians and patients alike. Although the medication provides pain relief, its administration has always instilled fear in one and all. The advances in equipment and techniques of local anesthesia administration have undergone continuous research and development to make it as painless as possible.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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**6**

## **Office-Based Anesthesia in Oral and Maxillofacial Surgery-The American Model and Training**

Payal Verma and Deepak G. Krishnan

#### **6.1 Introduction**

Anxiety and pain control has been the center of dental health provision from its inception. Dentists continue to practice some form of pain and anxiety control throughout the world. In the United States (US), Oral and maxillofacial surgery (OMS) has maintained a unique privilege where the surgeon is able to provide both anesthetic and surgical treatment for most of the procedures that are completed in a setting outside of the operation theater. The extensive, focused training received during OMS residency in the delivery of anesthesia, as well as continued education in anesthesia is central to this privilege. The art and science of alleviating pain and anxiety by providing offce-based surgical treatment using various anesthetic techniques is associated with tremendous responsibility. Therefore, appropriate training along with local licensure, credentialing, and continuous education is of paramount importance.

While the Commission on Dental Accreditation (CODA) of the American Dental Association (ADA) stipulates standards in training OMS residents in anesthesia, American Association of Oral and Maxillofacial Surgeons (AAOMS) and state dental societies have developed parameters and protocols that are enforced among practicing OMSs, ensuring patient safety.

For the remainder of this chapter, the term ambulatory anesthesia would refer to the provision of anesthesia outside of a hospital operatory, such as a dental or an OMS offce. Generally, this would entail provision of "open-airway" deep

P. Verma (\*)

Oral & Maxillofacial Surgery, University of Cincinnati Medical Center, OH, Cincinnati, USA e-mail: vermapl@ucmail.uc.edu

D. G. Krishnan

sedation with drugs delivered through an intra-venous (IV), intra-muscular (IM) or inhalational routes.

The American Society of Anesthesiology (ASA) recognizes four stages of anesthesia (Table 6.1) [1]. The most common forms of anesthesia used in an ambulatory offce setting are mild-to-moderate sedation as well as deep sedation/general anesthesia with the use of inhalational and intravenous agents. As defned by ASA, moderate sedation/ analgesia (replacing the term "Conscious Sedation," which has been condoned) is a medication-induced depression of consciousness during which patients respond purposefully to verbal commands, either alone or often accompanied by light tactile stimulation. Other interventions are not required to maintain a patent airway, while spontaneous ventilation is adequate, and cardiovascular function is usually maintained. Whereas deep sedation/analgesia is a drug-induced depression of consciousness during which patients cannot be easily aroused but respond purposefully following repeated or painful stimulation. The ability to independently maintain ventilatory function may be impaired and may require assistance in maintaining a patent airway. However, it is important that the cardiovascular function is maintained.

Given that the process of sedation is a continuum, the patient's response is unpredictable. Hence, practitioners should be able to rescue the patients whose level of sedation becomes deeper than initially intended. An oral and maxillofacial surgeon is well trained in airway management and advanced life support.

#### **6.2 Brief History of Anesthesia in OMS**

Over several decades, Oral and maxillofacial surgeons have been at the forefront of anesthesia and pain control among all dental specialties and have been providing safe outpatient anesthesia.

Nitrous oxide was produced by Joseph Priestly and was termed as "laughing gas" by Humphrey Davy in eighteenth

Oral & Maxillofacial Surgery, University of Cincinnati Medical Center, OH, Cincinnati, USA

Oral & Maxillofacial Surgery, Cincinnati Children's Hospital and Medical Center, OH, Cincinnati, USA

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 79

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_6


**Table 6.1** Continuum of depth of sedation: defnition of general anesthesia and levels of sedation/analgesia

century [2, 3]. It was frst used as an anesthetic agent in dental practice by Dr. Horace Wells [4] of Connecticut. He demonstrated the use of nitrous oxide for dental extractions that was aimed at the prevention of pain during surgery. Unfortunately, he was dismissed due to lack of medical background. His friend, William T G Morton [4], later demonstrated the use of ether vapors as anesthetic for the removal of a jaw tumor. Morton was therefore credited for the frst anesthetic (October 16, 1846; also known as Ether Day). This solidifed the foundation for the use of anesthetics in dental practice.

A prominent step forward in the provision of safe ambulatory anesthesia was the development and further refnement of the intravenous route of administration. It provided a safe route for rapid delivery and titration of medications along with giving the surgeon the ability to provide emergency medications. The practice of intravenous techniques allowed fast onset and recovery.

Adrian O. Hubbell [5] was critical in popularizing outpatient general anesthesia among OMS. He completed his training at Mayo Clinic and later demonstrated the safety of administering barbiturate anesthesia in an outpatient setting. He also advocated the utility and safety of recovering patients on their side or abdomen postoperatively to prevent aspiration of vomitus**.** Sylvan Shane [6] later reported on the use of intravenous drugs (benzodiazepines) for inducing sedation known as a "balanced" anesthetic. It was rapidly accepted due to its property of anxiolysis as a sole agent.

Another drug that became popular was methohexital [7] but was quickly overtaken by the introduction of Propofol [8], which is currently the most favored primary agent. In 1989, Propofol was offcially approved for use, and its benefts related to the faster onset, improved recovery, and inherent antiemetic activity were soon recognized.

It became evident soon that to continue the privilege of administering outpatient anesthesia, it was important to receive adequate formal general anesthesia training and to maintain the highest standard of care. Today, Intravenous drug anesthesia is the mainstay of providing sedation in the outpatient setting of oral and maxillofacial surgery and has a history of safety [9].

#### **6.3 The Anesthesia Team**

A majority of the OMSs in the US work in private practice settings where ambulatory anesthesia is the mainstay of practice. This has led to the development of a unique offce anesthesia model known as the Anesthesia Team model for OMS practice [10]. This was originally described as the operator-anesthetist model. That was a misnomer because in reality the entire team involved in patient care is trained to monitor and manage the patient under anesthesia in various capacities.

In a typical setting, it is the surgeon who performs the surgery and administers anesthesia. Apart from the surgeon, two or more other team members are present in the room (Fig. 6.1). At least one of these team members is required to be BLS (Basic life support) trained. Most commonly, one trained staff member observes the monitors, records drugs and vitals, and helps with i.v. drug administration, while another member acts as a surgical assistant. Assistant's job is to retract, suction, and irrigate during the surgery along with helping in supporting the airway (Fig. 6.2). Often surgeons employ a registered nurse with advanced cardiac life support (ACLS) training in their offces as well. The entire team is well versed with emergency equipment and is well trained to handle an airway emergency by providing positive pressure oxygen.

#### **6.4 AAOMS Ofce Anesthesia Guidelines**

AAOMS strives to ensure that its members throughout the country are in compliance with strict and mandated guidelines. It provides these guidelines through often-updated Offce Anesthesia Evaluation document made available through the association. These guidelines are created by the Committee on Anesthesia (CAN) of the AAOMS. This committee uses the latest evidence-based recommendations and guidelines to make this document. This document is then vetted by the ASA to ensure that it gets the highest level of scrutiny and approval by that organization. This multilevel peer-review process of the guidelines is important for ensur-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 6.1** Example of the offce anesthesia team. The surgeon provides the anesthesia and performs the procedure, one trained staff member supports the airway, and a second staff member is the surgical assistant

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 6.2** A dedicated registered nurse with ACLS training is often in charge of monitoring the patient under sedation

ing the safe delivery of anesthesia in the ambulatory OMS setting.

Every AAOMS member (close to 10,000 members) goes through a periodic offce anesthesia evaluation process by peers to ensure that each offce and team is current and well equipped to perform safe anesthetic practice in their setting (Fig. 6.3). Failure to pass such an evaluation leads to punitive action and inability to perform anesthesia in the offce setting until corrective actions are taken. AAOMS, state dental societies, and third-party insurance carriers take this process seriously. Public safety cannot be compromised.





**Fig. 6.3** Sample on site form for periodic offce anesthesia evaluation. Available at www.aaoms.org











**Fig. 6.3** (continued)

#### **6.5 Ofce Requirements**

The facilities where ambulatory anesthesia is provided in OMS practices are subject to stringent guidelines [11]. Specifc building codes and local fre department regulations have to be followed for installation of remote gases. Proximity to a larger healthcare facility and access to emergency personnel are of paramount importance. Recommendations per Centers for Disease Control (CDC) and prevention on controls for exposure to anesthetic gases and other potential chemical hazards, as well as sterilization of the instruments and facilities are enforced. Offce's fre safety and emergency protocols should be known by all staff and easily accessible for reference. Telephone numbers of the local ambulance service and nearest hospital should be clearly displayed and their location known to all offce staff.

#### **6.6 Record Keeping**

Medical record keeping is paramount in current OMS practice. For the purpose of OMS procedures, proper electronic records have to be maintained. This includes preanesthesia assessment forms, i.e., history and physical evaluation, consent forms, intraoperative anesthesia records, operative notes as well as recovery records (Fig. 6.4). Anesthesia records typically consist of vital signs (recorded every 5 min), type and amount of drugs administered with time of administration, start and end times of anesthesia and surgery, surgeon and other team members' names, and details of complications and management, if any.

#### **6.7 Ofce Anesthesia Evaluation Program and Parameters of Care**

Every practicing AAOMS member agrees to a uniform peer inspection of their properly equipped offce and their techniques and preparation for managing emergencies and complications of anesthesia in the treatment of the OMS patient in their offce or outpatient setting.

In 1975, the AAOMS established the Offce Anesthesia Evaluation Program. This program was conceived, developed, and implemented by the AAOMS through its component state societies to beneft the public, whom its members serve. This ensures a level of safety to the practice of anesthesia in the OMS offce, which is often outside a hospital or other healthcare facility. Since 1990, AAOMS Bylaws require offcial component societies' constitutions and bylaws to include provision for the fulfllment of an onsite offce evaluation based on the AAOMS Offce Anesthesia Evaluation Program as a prerequisite for active membership. The offce anesthesia evaluation is now required every 5–6 years for every AAOMS member.

AAOMS periodically offers an Offce Anesthesia Evaluation Manual [12] with the following intent—"AAOMS Committee on Anesthesia developed the Offce Anesthesia Evaluation Manual to provide information that could aid oral and maxillofacial surgeons in preparing themselves and their offces for the management of anesthetic complications. It presents scientifc and clinical information and can serve as a reference for the practitioner." The most recent evaluation manual is available for purchase by the members in 2019.

In addition, a separate document called "AAOMS Parameters of Care" [13, 14] is intended to refect practice considerations for 11 designated areas of oral and maxillofacial surgery and is an additional guide for AAOMS members to establish parameters of care for anesthesia in outpatient facilities. The most recent version of this document was published in 2017. The document provides complementary recommendations for the provision of safe sedation and anesthesia in the offce. Members are encouraged to review both documents, which provide essential information on contemporary OMS offce anesthesia practice and practice accordingly.

#### **6.8 AAOMS National Simulation Program**

AAOMS recognizes that the provision of anesthesia at an OMS offce is a team effort. It expects each member of the team—from the surgeon to the assistants—to be highly trained and qualifed to address every anesthesia-related situation that may occur during a surgical procedure. This training is initiated in OMS residencies but is continuous throughout the surgeon's career, mandated by continuing education and team exercised. Similar to professional sports teams, successful oral and maxillofacial surgery teams train as a unit to ensure they can seamlessly and quickly manage an unexpected airway emergency. The most recent AAOMS offering to help the offce anesthesia team partners with advanced simulation technology making it possible to train surgeons and staff by simulating a full range of real-life emergency airway situations [15]. This program allows participants to practice and master critical techniques for administering and monitoring offce-based anesthesia; a standardized approach that ensures that every participant experiences the same simulated events. The program allows for evaluation of each participant's performance and can pinpoint those areas that may beneft from additional training. The three-module program offers oral and maxillofacial surgeons and their staff an effective method of assessing their readiness to meet an offce anesthesia emergency situation by practicing these in a low-risk, high-stake simulation scenario.


#### **6.9 Dental Anesthesia Assistant National Certifcation Examination (DAANCE)**

The practice of offce-based anesthesia depends largely on the skillset of the assistants in the offce as much as it does on the surgeon leading the team. In an effort to elevate the education and knowledge base of the other team members, a program called the Dental Anesthesia Assistant National Certifcation Examination (DAANCE) was implemented nationwide. This is a continuing education program that comprises 36 h of self-education and a computerized exam to be completed in 6 months. This course is designed primarily for OMS assistants. Upon successful completion of the fnal examination, certifcation is provided.

The course is designed to cover important topics, including general review of basic sciences, patient's medical history evaluation, basic knowledge on anesthetic drugs and techniques, role of anesthesia equipment and monitoring, and covers basic maneuvers to handle offce anesthesia emergencies.

This course is available to allied staff all year round to register and complete. More and more states in the US are now mandating courses like DAANCE or others to all team members in an effort to keep the practice of ambulatory anesthesia team model safe and viable in the OMS offce.

#### **6.10 Anesthesia Training during OMS Residency**

OMS trainees in the US have a rigorous curriculum in anesthesia. The Commission on Dental Accreditation (CODA) of the American Dental Association (ADA) is the independent body that accredits all residency training programs. This accreditation is based on a peer-review process that enforces adherence to training standards created and vetted by the CODA. The educational standards for anesthesia read as follows:

4-3.1… Anesthesia Service: The assignment must be for a minimum of 5 months, should be consecutive, and one of these months should be dedicated to pediatric anesthesia. The resident must function as an anesthesia resident with commensurate level of responsibility.

*Intent: The pediatric portion could include Pediatric intensive care unit (PICU), Neonatal intensive care unit (NICU), pediatric anesthesia service, or ambulatory pediatric anesthesia. Oral and maxillofacial surgery residents rotating on the anesthesia service have levels of responsibility identical to those of the anesthesia residents, and abide by the anesthesia department's assignments and schedules. Part of this time can be during medical school as long as oral and maxillofacial surgery trainee functions at the anesthesia resident level.*

4-9… The off-service rotation in anesthesia must be supplemented by longitudinal and progressive experience throughout the training program in all aspects of pain and anxiety control. The ambulatory oral and maxillofacial anesthetic experience must include the administration of general anesthesia/deep sedation for oral and maxillofacial surgery procedures to pediatric, adult, and geriatric populations, including the demonstration of competency in airway management. Examples of evidence to demonstrate compliance may include:


4-9.1… The cumulative anesthetic experience of each graduating resident must include administration of general anesthesia/deep sedation for a minimum of 300 cases. This experience must involve care for 50 patients younger than 13. A minimum of 150 of the 300 cases must be ambulatory anesthetics for oral and maxillofacial surgery outside of the operating room. Intent: The cumulative experience includes time on the anesthesia rotation as well as anesthetics administered while on the oral and maxillofacial surgery service. Locations for ambulatory anesthesia may include dental school clinics, hospital clinics, emergency rooms, and oral and maxillofacial surgery offces.

Examples of evidence to demonstrate compliance may include:


4-9.2 …In addition to general anesthesia/deep sedation, the residents must obtain extensive training and experience in all sedation techniques.

Examples of evidence to demonstrate compliance may include:


4-9.3 …The clinical program must be supported in part by a core comprehensive didactic program on general anesthesia, deep sedation, and other methods of pain and anxiety control. The didactic program must include lectures and seminars emphasizing:


4-9.4 …Advanced Cardiac Life Support (ACLS) must be obtained in the frst year of residency and must be maintained throughout residency training and thereafter.

Examples of evidence to demonstrate compliance may include:

• ACLS certifcation records and cards

4-9.5… Each resident must be certifed in Pediatric Advanced Life Support (PALS) prior to completion of training.

Examples of evidence to demonstrate compliance may include:

• PALS certifcation records and cards

Adherence to these standards is strictly enforced ensuring a standardized education in anesthesia to each OMS resident in training in the US.

#### **6.11 Preanesthetic Evaluation of the Patient**

The OMS planning an offce-based anesthetic is trained to do a thorough preoperative evaluation of the patient to deem them ft for offce anesthesia. Just as an anesthesiologist would evaluate the patient for systemic disease, functional capacity and medications along with a detailed anesthetic history and physical examination to classify every patient into an American Society of Anesthesiologists (ASA) status (Table 6.2) [16], every OMS would do the same for formulating an anesthetic plan for the patient.

Ideally, ASA I and II patients are best suited for offcebased anesthetics. Careful preanesthetic patient evaluation is critical in choosing the type and venue for the anesthetic. This evaluation has the following essential steps:


This detailed preop evaluation gives the OMS the knowledge to classify all according to the ASA classifcation and adequately plan for an appropriate anesthesia technique**.**

#### **6.12 Monitoring**

Provision of anesthesia in the OMS offce requires that monitoring is done according to the ASA standards and more.

This includes the following minimal time-stamped monitoring and documentation [17].


**Table 6.2** ASA physical status classifcation system.


Developed By: ASA House of Delegates/Executive Committee

5. Ability to measure temperature, i.e., very essential in a setting where Malignant Hyperthermia (MH) triggering agents are in use.

Majority of OMS offces now use monitor units (Fig. 6.5) that interface directly with an electronic health record. The entire team is clued into monitoring with a staff member often dedicated to only monitoring the patient.

All patients receive supplemental oxygen before, during, and after the procedure. Most facilities have a separate recovery area with the same monitors, although there are several offces that recover in the operatory. The goal is the improvement of effcacious monitoring to establish the safe performance of anesthetic without the need for a separate anesthesia provider. It is imperative to have a meticulously trained team to allow for continuous monitoring, thus facilitating immediate recognition of changes in patient's vital signs. A properly evaluated and selected patient is unlikely to have a catastrophe in the OMS anesthetic, but when an untoward event does occur, it is often a respiratory event.

#### **6.12.1 Methods for Monitoring Ventilation**

Data available from closed claims cases from the OMS National Insurance Corporation (OMSNIC) allow us as a specialty to audit the near-misses and tragic outcomes from our offces. The data suggest a strong correlation between airway-related failure and adverse events in the open-airway anesthetic techniques. The emphasis is on monitoring of

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 6.5** Example of monitor commonly used in oral and maxillofacial surgery anesthetic administration. The single unit clearly displays the electrocardiogram, noninvasive blood pressure monitor, oxygen saturation, and end-tidal carbon dioxide

both ventilation and oxygenation to allow adequate monitoring of the respiratory system during anesthesia. This can be achieved by using a pulse oximeter, which is a device that measures oxygen saturation and provides an indirect indication of oxygenation. Recently, AAOMS recommended a newer ASA standard monitoring of ventilation with continuous capnography. Although chest movements are a reliable method but are least exact, hence the addition of capnography. Most OMSs use a pretracheal/precordial stethoscope (Fig. 6.6) to auscultate while the patient is sedated.

Historically, pulse oximetry has been used for respiratory monitoring. But due to its limitation in lacking real-time responsiveness to major respiratory events like airway obstruction or respiratory depression, there was an imminent need to incorporate a different parameter to provide a real-time assessment. Thus was developed capnography [18], which is the noninvasive measurement of the partial pressure of carbon dioxide (CO2) from the airway during inspiration and expiration. It can provide real-time sensitivity to early changes in ventilation and is reliable even in low-perfusion states.

Although, in the nonintubated sedated patient, there is loss of CO2 through the nose and mouth, and thus requires modifcation of the collection cannula, it still provides valuable clinical information on patient's ventilation during sedation.

It cannot be stressed enough how critical it is to manage intraoperative airway and monitor respiratory status. Ventilation is monitored by inspection of chest movement by the assistants, monitoring of capnography as well as auscul-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 6.6** (**a**, **b**) Pretracheal/precordial stethoscope used by the surgeon to auscultate while the patient is sedated

tation with a precordial stethoscope. The newer Bluetooth models of the precordial stethoscope allow wireless speakers that allow the entire team to listen to the patient's respiratory patterns.

Now with multiple modalities such as a real-time capnography tracing, listening to breath sounds with high fdelity, OMS team has an opportunity to assess and act promptly on potential airway threats even before the adverse respiratory event comes to light. With these available modalities, along with surgeon's experience and developed senses, anticipation and prediction of an impending laryngospasm or bronchospasm prompts the team to act preemptively. Even before a drop in oxygen saturation or loss of waveform on capnography becomes apparent, both the depth and rate of breathing as well as the cessation of breathing can be promptly recognized.

#### **6.13 Airway Armamentarium**

Despite several preventive modalities available to the OMS performing anesthesia, emergencies are bound to happen. The unit must be prepared to handle airway and other emergencies. All the anesthesia providers should be exceptionally familiar with emergency airway equipment that must be readily accessible in both the operating suites and the recovery area [11].

Emergency airway equipment must include full face mask, bag-valve-mask device capable of providing positive pressure ventilation, oral and nasopharyngeal airways, supraglottic airway devices, endotracheal tubes, and laryngoscope and cricothyrotomy kit. All these equipment should be available in both pediatric and adult sizes. The entire staff should have periodic in-offce training to familiarize themselves with the equipment and their use. Apart from emergency airway instruments, all offces are required to have either a basic monophasic defbrillator or automated external defbrillator.

#### **6.14 Oxygen and Supplemental Gas Delivery System**

In addition to oxygen, most OMS offces utilize other gases such as nitrous oxide and inhalational anesthetics as well as air. The oxygen delivery system should be able to deliver metered oxygen to the patient under positive pressure. A standard fail-safe mechanism along with scavenging system should be part of all gas delivery machines installed in the offce. This prevents delivery of any hypoxic amount of gases. To prevent the accidental administration of an incorrect gas, the gas outlets used should be pin-indexed. The gas delivery machines also are mandated to have periodic calibration records, which should be maintained with proper documentation stored at a known location. Anesthesia equipment, including ventilators, are similarly required to have a periodic inspection by biomedical engineers. The OMS offce is responsible for ensuring this happens and the offce anesthesia evaluation is a mechanism to keep a check on this.

#### **6.15 Suction Equipment**

As trivial as it may seem, the offce suction unit (central and portable) is an integral part of both the normal and emergency functions of that offce. A portable suction unit must be readily accessible in the operatory and recovery area in case of unanticipated power failure or central suction pump failure. Again, routine maintenance of the suction system and its documentation is required.

#### **6.16 Recovery Room**

Most OMS offces have a postoperative recovery unit separate from the operatory that allows unobstructed patient observation. The design of this area must allow resuscitation and management of the patient during an emergency. The recovery area should have a suction system, oxygen delivery system, all appropriate monitors and emergency equipment as detailed earlier. It is also the responsibility of the recovery nurse to document the patient's recovery from anesthetic to deem their ftness to leave the offce. A recovery checklist such as the Modifed Aldrete Scale is useful in making this determination.

#### **6.17 Techniques in Anesthesia**

Training in anesthesia exposes the oral and maxillofacial surgeon to the different modalities of anesthesia from light to deep sedation. As described before, levels of anesthesia are a continuum (Table 6.1). The effects of different drugs and techniques may vary between individuals. Patients may achieve deeper or lighter levels of anesthesia than anticipated based on their unique metabolic responses to the different anesthetics administration. The OMS team is prepared to anticipate these differences in responses and intervene accordingly.

The techniques utilized to get to different levels of anesthesia include inhalational anesthesia, oral anesthetic technique, parenteral anesthesia, and local anesthesia. Regardless of the technique employed, the goals of each of these techniques are to reduce anxiety, establish cooperation, amnesia and analgesia, ensuring comfort and hemodynamic stability. In order to choose the level of anesthesia, one should consider the age of the patient, level of anxiety and ability to cooperate, detailed medical history, and prior anesthesia experience.

#### **6.17.1 Enteral Anesthesia**

Oral or nasal route of delivery of drugs is the least threatening route of administration of anesthesia. While some anxiolysis is achieved via this modality, it is rarely used to achieve deeper levels of anesthesia. Often the oral route of sedation is used as a premedication prior to IV access in an uncooperative patient. Various ingestives such as syrups, popsicles, needleless syringes, other creative methods are employed to get the patient to consume the medication. Dosing is adjusted in such a way that a higher dose of the drug may be administered in a limited volume to prevent the likelihood of aspiration. Despite that, a crying child or a coughing adult may end up aspirating the medication. The other disadvantages of this technique include a slow onset and variable response to the action of the drug as well as an unpredictable recovery pattern. In an uncooperative patient, patient compliance will limit oral or nasal administration of any drug. Additionally, oral dosing is often empiric with almost predictable erratic absorption. Titration of the drug is diffcult via this route.

Yet, it remains a convenient mode of administration, requiring very little training to deliver, and any adverse reactions are slow to the onset and usually less severe and manageable. In the US, a medical provider providing oral sedation in the offce does not have an increase in their malpractice premiums because of this practice. In contrast, practitioners of general anesthesia have higher malpractice coverage due to the inherent risks of that practice.

An ideal oral medication must be able to provide rapid absorption, must have a rapid onset, and must have a high therapeutic index allowing rapid and predictable recovery.

The following are the drugs most commonly used in oral sedation techniques:


Oral sedation techniques are primarily useful in the OMS as a premedication tool. An orally sedated patient is likely to accept a mask or an IV for further induction of anesthesia. Several minor procedures, however, can be performed with oral sedation and good local anesthesia alone.

#### **6.17.2 Parenteral Anesthesia: Intravenous Anesthesia and Inhalational Anesthesia**

Hubbell [5] was known to promote the use of intravenous thiopental anesthesia. It was eventually replaced by the shorter-acting barbiturate methohexital. This became the primary agent used for offce-based anesthesia for multiple decades. A shortage in supply of methohexital and an increased use of Propofol [8] in the operating theater setting prompted an adaptation of the use of that drug in the offcebased anesthetic technique. The basic technique for deep sedation and general anesthetic in the nonintubated patient in the OMS offce typically employs a cocktail of medications under strict ASA-mandated guidelines for monitoring with the personnel as described earlier.

These medications include, but are not limited to, the following:


Most of these medications are characterized by their ability to have a rapid onset and offset. Medications such as Propofol rapidly redistribute and metabolize and are eliminated from the system. The combination of these medications often results in a cumulative effect of sedation and hypnosis in addition to central analgesia. Discomfort from the administration of local anesthesia is often obtunded by this level of sedation. Patients maintain their ventilation and careful monitoring of their vital signs and protection of their airway allows for smooth sedation. The surgeon who is performing the procedure is in close proximity to the patient's airway understanding its minute undulations and sensing the level of the patient's sedation and acting preemptively to either prolong or discontinue the sedation. It is an art and science that is built on years of training and experience.

The dosing of these medications is based on the patient's ideal body weight. The administration of these medications is through a continuous intravenous catheter infusion with an appropriate IV fuid. Typically, a 20- or a 22-gauge catheter is inserted into a peripheral vein in the upper extremity. Most OMSs practice the bolus technique, which introduces incremental doses of each medication, titrated to effect. Infusion pumps are often utilized in longer cases, while shorter cases of sedation seldom require infusion.

Using a continuous infusion has the following tangible advantages:


#### **6.18 Emergency Drugs**

The ninth edition of the AAOMS Offce Anesthesia Evaluation Manual [12] provides a detailed list of medications that can be used during anesthetic emergency. OMS offces are recommended to have a refrigerator designated for medications requiring cold storage. Pharmacy boards of different states control the storage and distribution of these drugs.

Listed are suggested drugs used in the event of anesthetic emergencies:


#### **Additional Drugs**

• Dextrose 50%, Dexamethasone (Decadron), Hydrocortisone sodium succinate or Methyl prednisolone sodium succinate (Solu-Medrol), Glycopyrolate (Robinul), Diazepam (Valium), Midazolam (Versed), Albuterol inhaler, Succinylcholine (Anectine), Morphine sulfate, Dantrolene (Dantrium), Lidocaine, Nonenteric-coated aspirin, Famotidine (Pepcid), Diphenhydramine (Benadryl)

### **6.19 Activism and Leadership in Ofce-Based Anesthesia**

Dental anesthesia is an ADA-recognized specialty in the US as of 2019. Several dental practitioners, including OMSs, practice anxiolysis and sedation in their offces, outside a hospital operating suite and without a separate anesthesia provider. The concerted efforts by various interested parties to politically organize and better protect our intellectual and political interests in the discipline make this practice a reality in the US.

To ensure the commitment to patient safety, the AAOMS and its Board of Trustees have embraced a multipronged approach:


The AAOMS developed an Anesthesia Safety Conference for our own specialty that was held on April 27, 2017, at the American Society of Anesthesiologists headquarters in Schaumburg, Illinois. Representatives of the ASA as well as representatives of the appropriate disciplines of dentistry attended this meeting. In April 2019, a second patient safety conference focusing on pediatric sedation was organized at the AAOMS headquarters in Rosemont, Illinois.

By staying on the forefront of offce-based anesthesia and by enforcing the highest standards of safety in patient care, OMS as a specialty has become stalwart in this arena. Continued positive momentum with nationwide simulation workshops and a mobile application supporting the offce anesthesia evaluation will enhance our role as leaders in ambulatory anesthesia in our offces. The rapid response and emergency system and the healthcare infrastructure in the US allows for OMSs in this country to adapt this technique and methodology into their practices almost effortlessly. In other parts of the world, this may not be a model that is easy to replicate.

#### **Video Links**

#### https://myoms.org/procedures/anesthesia

#### **References**

1. American Society of Anesthesiologists (ASA). Continuum of depth of sedation: defnition of general anesthesia and levels of sedation/ analgesia. (Approved by the ASA House of Delegates on October 13, 1999 and last amended on October 15, 2014). Available at: https://www.asahq.org/standards-and-guidelines/continuum-ofdepth-of-sedation-defnition-of-general-anesthesia-and-levels-ofsedationanalgesia


Guidelines for Oral and Maxillofacial Surgery (AAOMS ParCare) Sixth Edition 2017. Patient assessment. Available at: https://www. aaoms.org/images/uploads/pdfs/parcare\_assessment.pdf


#### **Additional Reading**

White Paper by American Association of Oral and Maxillofacial Surgeons (AAOMS). Offce-Based Anesthesia Provided by the Oral and Maxillofacial Surgeon. 2016. Available at: https://www.aaoms. org/docs/govt\_affairs/advocacy\_white\_papers/advocacy\_office\_ based\_anesthesia\_whitepaper.pdf

**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Anaesthesia for Maxillo Facial Surgery**

**7**

Rebecca Jacob, Subramanyam S. Mahankali, Renita Maria, Suman Ananathanarayana, Garima Sharma, and Mary Thomas

#### **7.1 Introduction**

Maxillofacial surgery encompasses a wide range of procedures on the head and neck, combining oral and facial procedures with the ear, nose and throat (ENT), plastic surgery, neurosurgery and base of skull specialities. It ranges from simple dental extractions to complex reconstructive and free fap surgery.

Patients of all age groups may present for maxillofacial surgery. The main issues involve managing a shared airway; providing good access to head, neck and oral cavity. The management of diffcult airways and measures to reduce tissue bleeding and oedema, both intra- and post-operatively pose a unique challenge to the anaesthetist. Good communication between all members of the team is essential [1].

#### **7.2 Preoperative Assessment**

All patients should be assessed preoperatively and an anaesthetic plan should be formulated as these patients may have a suspected or a known diffcult airway or are undergoing complex or prolonged surgery. Patients may give the history of poor oral intake and nutritional state due to pain, dysphagia and odynophagia. If dyspnoea is present, it should be evaluated as to whether it is cardiac or respiratory in origin.

M. Thomas

Previous surgeries, medication history and comorbidities diagnosed earlier should be noted. Medication history is important in all patients, especially elderly patients with cardiac, respiratory or renal involvement. It is also important to ascertain whether the patients have any comorbid ailments like hypertension, diabetes, thyrotoxicosis or myxoedema, a history of epistaxis or bleeding tendency and use of anticoagulants [2, 3].

#### **7.2.1 Patients on anticoagulants**

Patients on anticoagulants may present for emergency or elective surgery. The type of anticoagulant the patient is on should be noted during pre-operative assessment. Risk of peri-operative bleeding versus thrombosis on discontinuation of anticoagulants should be stratifed and accordingly discontinued or bridged with preferably unfractionated heparin or low-molecular-weight heparin prior to elective surgery. Usually, three half-lives (T1/2) discontinuation of anticoagulants prior to surgery is considered optimal to prevent blood loss (Table 7.1) [3].

In emergency situations, the main goals are discontinuation of anticoagulation, delaying semi-urgent procedures as appropriate and employment of reversal strategies like plate-

**Table 7.1** Recommendations for discontinuation of anticoagulation prior to elective surgery


American College of Chest Physician 2012 Guidelines published in Chest, the RE-LY trial published in Circulation 2014, the ROCKET AF trial, and the manufacturer's recommendations

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_7) contains supplementary material, which is available to authorized users.

R. Jacob (\*) · S. S. Mahankali · R. Maria · S. Ananathanarayana · G. Sharma

Department of Anesthesiology, Columbia Asia Referral Hospital, Yeshwantpur, Bangalore, Karnataka, India

Department of Anesthesiology, Regional Cancer Centre, Medical College Campus, Thiruvananthapuram, Kerala, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 95

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_7

let transfusions, fresh frozen plasma, vitamin K antagonists, and prothrombin complex concentrates.

The previous anaesthetic charts should be reviewed for the techniques used, ease of mask ventilation, best direct laryngoscopy grade, Endotracheal tube (ETT) size used, and any diffculties encountered and should be noted. The airway of previously operated patients may be altered due to previous surgeries and/or oedema, so this should be taken into account while reviewing the anaesthetic and follow-up records of the patient. If nasal intubation is required, one should enquire about nostril patency (history of nasal polyps or deviated septum). Contraindications to the use of controlled hypotension, e.g. cerebrovascular, reno-vascular and moderate-to-severe coronary artery disease should also be assessed. Specifc attention should be given to the needs of each class of patient.

#### **7.2.2 Oncology Patients**

Patients with head and neck cancer sometimes constitute the most challenging patients. Their upper airway may be seriously distorted, and they may have tracheal stenosis or hardening and fxation of the soft tissues due to radiotherapy.

In these patients, documents concerning previous surgeries, radiation and chemotherapy should be studied. The diffcult airway may have been encountered, tracheostomy and residual tracheal stenosis, limited mouth opening, and neck extension may have been recorded [4].

Symptoms such as hoarse voice, stridor, and dyspnoea will indicate whether there is airway compromise due to stenosis, tumour, nerve damage or oedema. Post radiation, the patients may have tissue fbrosis with limited mouth opening or neck extension. Make a note of chemotherapy drugs, duration and interval since the last cycle of chemotherapy.

#### **7.2.3 Trauma Patients**

Trauma patients require a thorough history of the mechanism of injury, which would indicate intracerebral or spinal injury. Drug and/or alcohol ingestion is often a contributory factor, and 15% have other injuries. There is also potential for injuries to other organs and massive blood loss. Cervical spine injury occurs in 5–10% of patients with blunt trauma to the head and face. Therefore, the patient should be evaluated from 'head to toe' [5].

#### **7.2.4 Paediatric Patients**

Consider age, weight, prematurity, feeding, nutritional status and position during sleep. In patients with craniofacial abnormalities, look for associated syndromes such as Pierre Robin sequence or Treacher Collins syndrome as in addition to a diffcult airway these patients may have involvement of other systems, such as cardiac, as a part of the syndrome, which will require specialist consultation [6].

#### **7.2.5 Toxic Airway/Infections**

Infection of dental and facial structures commonly leads to erythema and swelling of tissues. This can result in obstruction of airway and diffculty in airway management. Toxic airways (e.g. Ludwig's angina, dental cysts and osteomyelitis) with spreading infection often present as acute emergencies and may pose an extreme airway maintenance challenge. Direct laryngoscopy due to trismus, tissue distortion, oedema or abscess cavity and pus may not be possible and other means of securing the airway must be considered [4] (Fig. 7.1a, b).

#### **Examination Table 7.2**

#### **7.3 Airway Assessment**

A detailed airway assessment based on criteria in the 'L-E-M-O-N' method would help to stratify the risk of diffcult intubation. The 'LEMON Law' can be used to quickly assess for potentially diffcult airways [7]. A total score of 10 can be given as per the criteria and higher scores are associated with poor glottic visualization and diffcult intubation.

Please refer the Fig. 2.2 on LEMON in Chap. 2 on preoperative evaluation and investigations.

In paediatric patients, the Mallampati score does not accurately predict a poor view of the glottis and there are no standard values for the thyromental and horizontal length of the mandible. Thus, an adaptation is required, and this is found in the 'COPUR SCALE' (Table 7.3) [7, 8].

Once the airway assessment is done, check


©Association of Oral and Maxillofacial Surgeons of India

**Table 7.2** Checklist of things for a safe surgery

Pre-Anaesthesia Checklist


#### **7.4 General Physical Examination**

Look for pallor, icterus, cyanosis, clubbing, lymphadenopathy and oedema as well as the general nutritional status. Follow this up with pulse rate, blood pressure, respiratory rate, oxygen saturation, signs of dehydration, and responses denoted as AVPU–Alert, Verbal, Pain, Unresponsive.

AVPU is a simplifed version of the Glasgow Coma Scale (GCS), which is easy to remember and apply to patients (Table 7.4) [9, 10]. It consists of four possible stages. When recording AVPU, it is important to document the time the observation was taken and to track any changes over time as this will help monitor the progress of the patient (Table 7.4).

Apart from these, specifc systemic examination, including cardiovascular, respiratory, per-abdomen and central nervous system, should be done and if in any doubt a specialist should be consulted.

There are various scales used to record a patient's level of consciousness. One of the most detailed is the GCS, which is used worldwide (Table 7.5) [9, 10]. The GCS is a reasonably complicated system, which, unless you use regularly, can be diffcult to remember and apply correctly.

#### **7.4.1 Investigations**

In addition to routine blood tests like complete blood counts, kidney function tests, blood sugars, coagulation profle, serology, blood grouping and cross-matching is required for major surgery.

Chest X-ray helps in visualising any pathology in the lungs. It may also reveal tracheal deviation. X-ray soft-tissue neck, airway ultrasound, computerized tomography (CT), and magnetic resonance imaging (MRI) scans may be helpful in cancer, infections, abscesses or trauma cases.

For cancer surgery, a nasoendoscopy & indirect laryngoscopy provides valuable information about the upper airway anatomy.

Electrocardiogram (ECG), echocardiogram, cardiopulmonary exercise testing or pulmonary function tests are required if there are symptoms or signs of cardiorespiratory disease.

#### **Table 7.3** Description of COPUR scale


*Prediction points for ease of intubation*

5–7: Easy normal intubation

8–10: Laryngeal help may be required

12: More diffcult, may be less traumatic

14: Diffcult intubation, fbre optic or other advanced technique may be required

16: Dangerous airway, consider awake intubation/potential tracheostomy

**Table 7.4** AVPU scale described with examples


**Table 7.5** Glasgow Coma Scale described in detail


#### **7.4.2 Counselling and Reassurance**

This is essential in all cases but especially so in patients who may have dramatic cosmetic changes or are undergoing cancer surgery like hemi-mandibulectomy. The possibility of tracheostomy and loss of voice must also be discussed with empathy. Video counselling may be resorted to in case of need.

#### **7.4.3 Informed Consent**

Any patient above the age of 18 years may give consent for surgery and anaesthesia. In the case of patients younger than 18 years, consent must be obtained from a parent or guardian after full explanation of procedures. The consent must be documented and signed by both the person taking the consent and the person giving the consent.

#### **7.4.4 Transport to Operation Theatre (OT)**

Should be with a trained health care worker especially if the patient has been given a sedative premedication. It is advisable for a parent or guardian to accompany younger children to the OT.

#### **7.4.5 Handover Documents**

All documents pertaining to the case must be handed over to the OT personnel and the handover documented.

#### **7.5 Intraoperative Considerations**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 7.2** Anaesthetic apparatus

• Continue oxygenation with spontaneous respiration and wake up the patient if intubation is unsuccessful

*More patients have died from lack of oxygen than from lack of an endotracheal tube!*

*Please see Chap. 42 in this book to read about avoidable human errors for a safer patient care. (A case of loss of airway is discussed in Chap. 42).*

### **7.5.2 Induction**

Anaesthesia may be induced either intravenously or with an inhalational agent. The choice of technique depends on:


### **7.5.3 Monitoring**

In young patients belonging to ASA (American Society of Anesthesiologists) Grade I and II, standard monitoring will suffce. Invasive arterial blood pressure monitoring may be required if controlled hypotension is planned or if comorbidities warrant. Monitoring of temperature is required in children and those undergoing prolonged surgeries like corrective LeFort osteotomies. Urinary catheterization may be required during prolonged surgeries.

### **7.5.4** *Airway management:* (Flow Chart 1)

The method of securing the airway should be discussed with the surgeon. This depends on:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 7.3** (**a**) Nasal airway, (**b**) Oral airway, (**c**) Ventilation mask and (**d**) Laryngoscope blades

**Fig. 7.5** RAE tubes

Simple intraoral operations with no anticipated diffcult airways can be done with standard nasal intubation or oral intubation under general anaesthesia with endotracheal tube pushed to the side opposite of surgery. Use of specially preformed tubes like RAE tubes and Reinforced/Armoured tube can be used to give good access to the surgical area (Figs. 7.4

and 7.5). However, major corrective surgeries will require the oral cavity to be empty and hence warrant nasal intubation, submental intubation or a tracheostomy. Anticipated non-obstructed diffcult airway as assessed by history and/or examination or suspected (cervical) C-spine injury should be managed with awake fbre optic bronchoscopy or blind nasal

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 7.7** Diffcult airway cart

intubation. The safety of awake intubation relies on the maintenance of spontaneous breathing, and the ability to stop and perform a different technique, such as awake tracheostomy, if intubation is unsuccessful. Most anaesthesiologists prefer the nasal route for fbre optic intubation, as it is technically easier. For this, the patency of the nostril should be assessed preoperatively, and roomier nostril should be chosen and prepared with vasoconstrictor drops like oxymetazoline hydrochloride.

Sedation may enhance the acceptability of awake fbre optic intubation. Dexmedetomidine infusion [11] serves this purpose very well. Airway instrumentation can be facilitated by local anaesthetic topicalisation of airway either by means of lignocaine nebulisation or 'spray as you

**Flow Chart 1** Airway management in oro-maxillo-facial surgery

Failed

go' technique and/airway blocks (glossopharyngeal, superior laryngeal and recurrent laryngeal nerve blocks) [12]. An antisialogoguelike glycopyrrolate administered 30–45 min prior will reduce the secretions and will facili-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 7.9** (**a**,**b**,**c**,**d**) Supraglottic airways

tate awake fbre optic intubation. Airway blocks may not be an option to facilitate awake intubation in cases such as extensive pan-facial fractures or post-radiation fbrosis of the neck. Fibre optic intubation may be impractical in case of oro-maxillofacial trauma if associated with severe airway bleeding that can obscure visibility and other options such as tracheostomy under local anaesthesia (LA) should be considered.

The traditional 'blind nasal intubation' is rarely employed these days but may be used if a fbre optic scope is not available or not possible (Video 7.1).

A 'plan B' should always be present if intubation by one method is unsuccessful.

During long surgery and if ventilated in the post-operative period, the Endotracheal (or tracheostomy) cuff pressure should be measured using an aneroid manometer. A pressure of 20–30 cm of H2O is considered as standard in adults.

In supraglottic obstruction—associated with stridor and respiratory distress, as in case of upper airway trauma, rapidly expanding infections like epiglottitis, Ludwig's angina, etc. awake fbre optic bronchoscopy and intubation may not be the right choice. In such a situation, an awake tracheostomy under local anaesthesia must be considered.

#### **7.5.5 Supraglottic Airway Devices**

Several varieties of supraglottic airway devices are available (Fig. 7.9). However, these are not ideal devices for oromaxillofacial surgeries requiring the oral cavity to be empty, but can be lifesaving as rescue devices in 'cannot ventilate, cannot intubate' situations to ventilate a patient until the defnitive airway is secured. However, a fexible reinforced LMA can be used for simple dental extractions and nasal, zygomatic and superfcial facial surgery. However, obstruction and dislodgement can occur, especially when the mandible is moved.

#### **7.6 Special Considerations**

*Paediatrics:* [6] Children will not co-operate for awake fbre optic intubation. Hence, in such cases, the airway can be secured after inhalational induction without relaxation after establishing IV access. A nasopharyngeal airway may be passed gently into one nostril and connected to a breathing circuit while monitoring the end-tidal carbon dioxide (EtCO2) and continuing the anaesthetic and oxygenation via the airway. The other nostril may now be prepared with a vasoconstrictor and local anaesthetic and used for fbre optic intubation (Fig. 7.10).

#### **7.6.1 Retromolar and Submental Intubation**

These techniques were developed as alternatives to tracheostomy in maxillofacial surgeries requiring intra-operative inter-dental fxation for malocclusion correction like comminuted fracture of the mid-face or the nose, where nasal intubation is contraindicated.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 7.10** Fibre optic intubation in children

**Fig. 7.11** Retromolar intubation

#### **7.6.1.1 Retromolar Intubation**

Pre-operatively check the adequacy of the retromolar space. This is done to prevent kinking of the endotracheal tube in retromolar space by insinuating the index fnger behind the third molar and asking the patient to clench his teeth. The patients' airway is then intubated by the conventional method and the ETT is pushed in the retromolar space and brought out from the angle of the mouth and connected to the ventilator. The spiral reinforced/armoured ETT is preferred as it is kink resistant (Fig. 7.11).

#### **7.6.1.2 Submental Orotracheal Intubation:** [13] (Fig. 7.12a–f)

(See additional reading material on submental intubation given at the end of the chapter).

Just like retromolar intubation, it also requires the use of a spiral reinforced/armoured ETT in order to prevent the tube from kinking during its usage. Following conventional orotracheal intubation, a 2-cm incision is made lateral to the midline between the chin and the angle of the mandible and an opening is made in the foor of the mouth by the surgeon, avoiding the submandibular salivary glands. The machine end of the ETT without the connector is pulled through the tunnel, using gentle rotational movements. Following this manoeuvre, the tube is connected to the ventilating machine and sutures are used to fx the tube in position. If the procedure of disconnecting the ETT is long and pulling it out is prolonged, there is a possibility of hypoxia. So monitor oximetry closely and use high oxygen concentrations immediately before and after the placement of the submental tube (Video 7.2).

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 7.12** (**a**–**f**) Various steps in submental intubation

#### Securing ETT in Maxillofacial Surgery

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 7.13** Securing ETT in maxillofacial surgery

#### **Securing the Endotracheal Tube**

The ETT may dislodge intra-operatively as the airway is shared between the surgeon and anaesthetist; hence, special attention should be paid to securing the ETT. Preformed nasal RAE tubes, if used, should be supported on the nasal bridge and forehead with the help of preformed supports or pads and secured on the forehead with tapes in addition to securing at the nostril (Fig. 7.13). Submental tubes can be secured with sutures (Fig. 7.14) South Pole oral RAE tubes are usually fxed in the middle of the lower jaw with tapes (Fig. 7.15).

#### **7.6.2 Eyes**

Preferably taped with transparent dressing or specialized eye pads to capture moisture and prevent drying especially during prolonged surgeries (Fig. 7.15).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 7.14** Securing submental tube with sutures

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 7.15** Securing oral south pole tubes/protection of the eyes with tapes

#### **7.6.3 Positioning**

Reverse Trendelenburg (anti-gravity) position with shoulder roll for adequate surgical exposure is preferred. Further, the operation table may be turned away from the anaesthetist and the anaesthesia machine by 90° or 180°. Hence, long breathing circuits, IV extensions and long cables for monitoring will be required.

#### **7.6.4 Throat Pack**

Saline-soaked throat packs will be required to protect the airway from blood, debris and saliva. It is advised to fx the tail end of the throat pack to the oral endotracheal tube whenever feasible to prevent accidental leaving behind of the throat pack at the end of surgery. Time of insertion and removal of the throat pack should be documented and carefully checked before extubation. If interdental wiring is planned at the end of surgery, then prior to doing so all throat packs should be removed and gauze counts should be confrmed.

#### **7.7 Maintenance of Anaesthesia**

Once the airway is secured, anaesthesia can be maintained with total intravenous anaesthesia (TIVA) or with volatile anaesthetics or combination of both as described earlier. Controlled ventilation with an intermediate-acting muscle relaxant such as atracurium or vecuronium is used.

Intra-operative analgesia is preferably provided with short-acting opioids such as fentanyl. Dexamethasone can be administered intra-operatively to reduce post-operative swelling, for its analgesic properties and as a prophylactic against post-operative nausea and vomiting (PONV) [14]. Orthognathic surgeries are associated with a high incidence of PONV; hence, additional antiemetics such as ondansetron should be administered prior to extubation especially if interdental wires are planned. Hypothermia can be a potential complication of prolonged orthognathic surgeries. Hence, temperature should be monitored and warming measures like intra-operative warm I.V fuids, forced air mattresses should be used. If there is a fear of airway compromise postextubation, a tracheostomy should be done electively.

#### **7.7.1 Deep Vein Thrombosis (DVT) Prophylaxis**

Cancer patients and patients undergoing long surgery are at risk of developing thromboembolic complications. One or more of the following methods may be used to reduce its incidence.

Mechanical—Thromboembolic deterrent/Compression stockings (TEDS), pneumatic calf compression boots.

Pharmacological—Low-molecular-weight heparin such as Clexane could be used in patients at high risk for venous thromboembolism (VTE).

#### **7.7.2 Control of Bleeding**

The head and neck region receives rich blood supply from the branches of the carotid artery, and hence there is a tendency to bleed profusely during maxillofacial surgeries. Major bleeding can occur from branches of the maxillary artery or from pterygoid venous plexuses, leading to signifcant blood loss, warranting blood transfusion. Further, some of these procedures especially corrective osteotomies are extensive and time consuming. Surgical haemostasis is hampered by limited access. Risks involved in allogeneic blood transfusion have also been well documented and hence it is important to institute measures to reduce intra-operative blood loss and blood transfusion.

**Methods to control intra-operative blood loss include:** Reverse Trendelenburg (anti-gravity) positioning. Ensuring adequate venous drainage.

Antifbrinolytics, e.g. Tranexamic acid.

Infltration of the tissues with vasoconstrictors like adrenaline.

Controlled hypotension.

Intermittent positive pressure ventilation and maintenance of mild hypocarbia.


Over the years, several protocols have been developed. The main strategies are


Standard anaesthesia with Non-pharmacological measures: This relies on


*Pharmacological measures:* It relies on drugs used to either deepen the plane of anaesthesia and/or produce vasodilatation.

The ideal drug used for controlled hypotension should be easy to administer, quick in onset and recovery with predictable effect, no toxic metabolites and should preserve organ perfusion [17]. At present, no such drug is available and hence a combination of drugs is often used.

Deep anaesthesia can be achieved either with volatile anaesthetics or with intravenous agents.

Most volatile anaesthetic agents are potent vasodilators. This property can be exploited to reduce blood pressure. However, when used alone, the minimum alveolar concentration (MAC) values required to achieve this are high and can result in hepatic and renal injury and also delay awakening. They are therefore used at lower concentrations with other pharmacological agents. Most commonly used volatile agents include isofurane, sevofurane and desfurane. Halothane is preferably avoided due to its arrhythmogenic potential with adrenaline.

*Propofol Infusions:* This has been extensively used in neuro anaesthesia for controlled hypotension as part of total intravenous anaesthesia (TIVA). It can be used either as part of TIVA or combined with volatile anaesthetics.

*Opioids:* Opioids decrease the doses of agents required to produce anaesthesia and hypotension by decreasing pain. Most commonly used short-acting opioids include fentanyl and remifentanil.

#### **7.7.2.1 Hypotensive Drugs: (Appendix II)**

Hypotension should be carried out only to that level needed to reduce bleeding and only for that time of the surgery where it is of beneft in reducing signifcant blood loss. A number of drugs have been tried either alone or in combination to reduce blood pressure. While using them, one needs to be aware of their potential complications and contraindications. Drugs commonly used are beta-blockers, glyceryl trinitrate and sodium nitroprusside. Newer drugs like dexmedetomidine along with a propofol/remifentanil combination are gaining popularity [18, 19].

Invasive arterial blood pressure monitoring is recommended if infusions of hypotensive drugs are used for controlled hypotension. Intra-op serial monitoring of ABG (arterial blood gases), acid–base balance and lactate levels


with hourly urine-output measurement should help to prevent organ dysfunction.

*Isovolaemic haemodilution* was once considered an adjunct in orthognathic surgeries to induce hypotension to reduce blood transfusion. It has become less common these days. The technique involves preoperative blood donation with IV fuids replacement of circulating volume followed by autologous whole blood transfusion as needed in the intra- or post-operative period.

*Intra-op Analgesia* can be achieved with NSAIDs, Paracetamol, opioids, intraoral LA infltration and by mandibular or maxillary nerve blocks performed intra-op by the surgeon.

*Intra-operative complications:* The anaesthetist must be aware of and prepared for potential intra-operative complications [20, 21] (Table 7.6).

#### **7.7.3 Elective Tracheostomy**

Indications for elective tracheostomy are:

	- Certain head injuries
	- Massive chest injuries
	- Incidental pre-existing disease

Inadequate postoperative nursing care.

#### **7.8 Post-Operative**

*Emergence and extubation* [22] Flow Chart 2—AIDAA (All India Diffcult Airway Association) Guidelines for the management of anticipated diffcult extubation and Table 7.7.

(fow chart 2 re-used with permission from IJA and AIDAA)


#### 7 Anaesthesia for Maxillo Facial Surgery



MMF with elastics often applied, albeit later (from hours to 1 or 2 days) into the recovery phase where mouth opening will not be a problem.


#### **7.8.1 Handover from OT to Recovery Room/ICU**

#### **Clinical Criteria for Shifting:**

	- SpO2 > 95% on room air
	- Pulse rate optimum for age
	- Respiratory rate < 30/min
	- Normothermic

Anaesthesiologist should accompany patient to recovery

	- Name and age of patient
	- Surgery done
	- Any positive history and examination
	- Type of anaesthesia and drugs (time and dose) given, including analgesics.
	- Any intraoperative event
	- Clear postoperative orders

In case of inadequate postoperative care facilities like an ICU, the patient may be required to be sent to another hospital (see appendix III and 1V).

#### **7.9 Post-Operative Complications and Management**

	- Airway Problems
	- Postoperative bleeding and haematoma
	- Nausea and Vomiting
	- Post-operative pain

#### **7.9.1 Airway Problems**

In the post-anaesthesia care unit (PACU) the close monitoring of complications should be done, which can lead to airway obstruction such as soft-tissue swelling and formation of haematoma. Capnography may provide an earlier warning of serious problems than pulse oximetry when supplemental oxygen is being administered. Even in uncomplicated cases, the effects of residual anaesthetic agents on airway physiology are more pronounced in patients with MMF who may experience increased resistance to breathing.

#### **7.9.2 Post-Operative Haematoma**

Haematoma formation in the early postoperative period is an uncommon but potentially airway-threatening complication of some maxillofacial operations, notably neck surgery, thyroid resections and foor of mouth surgery. The rate at which airway compromise occurs is variable. Emergency decompression of the haematoma may be even done at the bedside. It involves removing the clips/sutures and manually evacuating the haematoma with a Yankaur sucker. However, this may not alleviate the airway obstruction adequately due to oedema that results from venous congestion. The airway needs to be secured urgently. The method of securing the airway should take into consideration information from the initial operation, but it is expected to be more challenging and may require expert airway management.

#### **7.9.3** *Nausea and vomiting* [23]

Factors that predispose to PONV include the female gender, a history of motion sickness, a low threshold for nausea, preoperative anxiety, obesity and gastric distension. Volatile anaesthetic agents, nitrous oxide, opioid usage and intubation have also been implicated as has prolonged surgery, early oral intake and certain types of surgery, including maxillofacial surgery.

Vomiting in patients with MMF is dangerous as it may predispose to aspiration. If the jaws are wired together, there must be wire cutters immediately available, which accompany the patient from theatre, to the PACU, and also to the ward.

Elastics in MMF can be cut easily with ordinary scissors.

PONV prophylaxis is best given round the clock for the frst 24 h and longer if opioids continue to be used. If treatment for PONV is required within 6 h of PONV prophylaxis, it should ideally be with a different class of anti-emetic drug to that used initially *(See Appendix I).*

#### **7.9.4** *Analgesia* [23–25]

After orthognathic surgery immediate postoperative pain is often not severe, and this is contributed to by the generous intra-operative use of local anaesthesia. A multi-modal analgesia approach should also be utilized perioperatively by combining opioids with paracetamol and non-steroidal antiinfammatory drugs towards the end of the case.

Patient Control Analgesia (PCA): It allows the patient to self-administer intravenous analgesics by means of a computer-controlled pump. It administers the pre-programmed dose on demand by the individual.

#### **7.10 Case Scenarios**

Case 1: Problem-Based Learning Tool Case 2: Multiple choice questions

#### **7.10.1 Case 1: Cleft Palate**

A 10-month-old child presents for surgery with a cleft palate


#### Examination


Investigations


In addition:


*Monitors*: ECG, NIBP, Pulse Oximeter, EtCO2, and airway pressure (once intubated)

#### *4. What are the problems that can present during anaesthesia?*

	- kinking of tube when the gag is placed
	- accidental extubation during positioning of the baby or removal of the gag
	- tube may be pushed endobronchially resulting in one lung ventilation when gag is applied
	- throat pack/other packs may be left behind after surgery causing airway obstruction

#### **7.10.2 Case–2: Polytrauma with Facial Injuries**

A 27-year-old male presented with the history of polytrauma following a road traffc accident. He gives a history of brief period of loss of consciousness following injury. No history of seizures, or other comorbidities. On examination, his GCS was 15/15, and he was haemodynamically stable. Airway examination revealed restricted mouth opening of just one fnger breadth, a short neck and a lacerated wound on the lower lip and chin with emphysema on the left side of the face extending into submandibular region. Cardiovascular, respiratory, abdominal and central nervous system examination was unremarkable. Blood investigations revealed increased CPK.

CT brain and spine showed a 3.5-mm extra-dural haemorrhage in the right temporal region, right frontal haemorrhagic contusion, an undisplaced fracture of the body of the mandible in bilateral parasymphyseal region with a displaced right zygomatic arch, a comminuted, mildly displaced fracture of right squamous temporal bone and undisplaced fracture of superior facet of C5 vertebra (Fig. 7.16).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 7.16** Photograph of a patient with polytrauma & facial injuries

#### *Questions*:

	- a. Cervical spine injury occurs in up to 10% of cases
	- b. Drugs and alcohol could be a contributing factor
	- c. Potential for injuries to other organs & massive blood loss
	- d. Injuries in children are less severe than in adults
	- a. Fracture Mandible
	- b. Presence of trismus
	- c. Cervical collar
	- d. # of superior facet of C5 vertebra
	- a. Pneumothorax
	- b. Tracheal injury
	- c. Soft-tissue injury
	- d. # involving sinuses
	- a. Receding mandible
	- b. Facial injury
	- c. Edentulous
	- d. Cervical collar
	- a. CT scan of head
	- b. MRI scan of head
	- c. X-Ray Skull
	- d. Careful clinical examination
	- a. Conventional laryngoscopy with oral endotracheal intubation.
	- b. Conventional laryngoscopy with nasal endotracheal intubation.
	- c. Fibre optic bronchoscopy with nasal intubation.
	- d. Conventional laryngoscopy with manual in line stabilization with nasal endotracheal intubation.
	- a. Regular endotracheal tube
	- b. Nasal RAE tube
	- c. Oral RAE tube
	- d. Reinforced cuffed endotracheal tube
	- a. Diffcult mask ventilation
	- b. Diffcult laryngoscopy
	- c. Both a) and b)
	- d. Normal ventilation and laryngoscopy.
	- a. Invasive arterial pressure
	- b. Urine output
	- c. Central venous pressure monitoring
	- d. BIS monitoring
	- a. General ward
	- b. Special ward

d. HDU

Answer: d). HDU will be an appropriate place to monitor this patient post operatively

	- a. NSAIDs
	- b. Nerve blocks
	- c. Tramadol
	- d. PCA Fentanyl
	- a. Dextrose-containing solutions
	- b. Balanced salt solutions
	- c. Hypertonic saline
	- d. Colloids

Answer: b) Balanced salt solutions



#### **Appendix II: Commonly Used Drugs for Controlled Hypotension**


c. ICU

#### **Appendix III: Handover Form Used for Inter Hospital Transfer**



#### *Vitals before transfer:*


#### *Transfer details:*



#### *Vitals on arrival/admission:*


#### *Handover details:*

Clinical summary: Y / N Patient records: Y / N Investigations: Y / N


#### **Appendix IV: Inter-Hospital Transfer Guidelines**

The transfer of the patient to a Centre where intensive care is available may sometimes be required if the facilities at the current hospital are inadequate. Most of these patients are critically ill and need the utmost care and planning to ensure safety during transfer. It is the responsibility of the referring team (surgeon as well as anaesthesiologist) to ensure a safe handover to the new treating team of doctors.

The following guidelines may be used to develop local protocols for inter-hospital transfer.

	- Ambulance services.
	- Suffcient oxygen supply.
	- Shifting trolley.
	- Battery backup for equipment.
	- Mode of ventilation (for intubated patients).
	- Adequate monitoring (ECG, pulse oximetry, blood pressure).
	- Resuscitative medications (preflled syringes).
	- Required paperwork—clinical summary, patient records and investigations.
	- Knowledge of destination hospital location and contact numbers.
	- Clinical stability of the patient should be confrmed before shifting.

adequate battery backup. In case of an intubated patient –DO NOT EXTUBATE just prior to transfer.


#### **References**


Singaravelu R, Das S, Myatra SN. All India diffcult airway association 2016 guidelines for the management of anticipated diffcult extubation. Indian J Anaesth. 2016;60(12):915–21. https://doi. org/10.4103/0019-5049.195484.


#### **Additional Reading (Sub Mental Intubation)**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

**Part IV**

**Imaging in Oral and Maxillofacial Surgery**

## **Radiology for Maxillofacial Surgeons: The Essentials**

Shyamsundar K. Joshi and Annie I. Kochuveettil

#### **Learning Objectives**


#### **8.1 Introduction**

Accurate diagnosis is the mainstay of proper surgical management in a maxillofacial surgical patient. Defnitive diagnosis may be possible in a few patients based on clinical evaluation in the outpatient department or emergency setup. Other cases may require the use of supplementary investigations, including radiological imaging.

Like other medical specialties, the scope of Radiology is vast, playing a signifcant role in disease management. Penning a chapter on Radiology for a clinical branch-like Maxillofacial surgery is an uphill task. As a clinician, the maxillofacial surgeon, after having made the diagnosis, has the desire to visualize and gain in-depth knowledge of the ongoing disease process within the patient. Radiology plays an important supporting role in helping the clinician visualize within the patient's body. It is hence necessary for clinicians to have basic knowledge of the key concepts of Radiology, helping them understand its applications in the diagnosis of a patient's clinical condition.

The scope of practice of a practicing MFS includes both surgical and nonsurgical problems that affect the orofacial region, and hence they need to be well versed with the imaging concepts of the head and neck region.

#### **Head and Neck Imaging**

Anatomy of the head and neck is complex and imaging in this region poses several challenges and an MFS needs to be cognizant of them.

Modern imaging has the unique advantage of being able to:


Conventional Radiography is one of the modalities that have been available from early days, ever since X-rays were discovered by Wilhelm Conrad Roentgen in 1895. However, it is regarded as a poor choice for anatomical evaluation due to overlapping of anatomical structures especially in the head and neck region. Yet it still has a popular role in its own humble way. It is universally available, the least timeconsuming imaging investigation, and gives a 'bird's eye view' of the region of interest. It provides instant practical

**8**

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 121

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_8

S. K. Joshi (\*) · A. I. Kochuveettil

Department of Radiology, SDM College of Medical Sciences and Hospital, Shri Dharmasthala Manjunatheshwara University, Dharwad, India

information on the status of the airway and osseous elements, helps inferring the underlying pathological process based on the presence of air pockets or bony destruction, and at times may even refect systemic pathology. It guides the clinician as to the further steps to be taken for patient management or to the need for further imaging. Despite it being the era of advanced technology, conventional radiography should invariably be the frst choice among imaging investigations. In cases of complex maxillofacial injuries and polytrauma, when the patient's clinical status demands the next level of investigation, CT may be performed frst, bypassing conventional radiography.

Pioneers in the feld of imaging had a yearning to develop modalities that could demonstrate fner anatomical details in the region of interest.

This, coupled with the technological evolution, has paved the way for the development of various radiological imaging technologies that include:


These advances in imaging techniques have enabled the MFS to diagnose with greater confdence and refne their approach to surgical treatment. This has also led to a reduction in unexpected surprises springing up on the surgical table.

Considering that a range of imaging modalities are available, it is imperative that the MFS has basic knowledge about their functionality, being familiar with the advantages and disadvantages of each so that the appropriate imaging investigation that gives the most optimal information in a given clinical setup can be selected. The rationale behind choosing the right investigation is that it should be easily available, least time consuming, cause least possible discomfort to the patient and be economical. Appropriate use of the concerned imaging modality should provide the maximum possible anatomical and functional information. This is possible if a genuine effort is made by an MFS to understand the basic principles and other related components of specifc diagnostic imaging relevant to his feld of interest and establish a close rapport with the imaging department.

#### **8.2 Requesting an Imaging Investigation**

Prior to requesting a radiological investigation, the MFS needs to have a clear idea about the usefulness of an investigation, its limitations, and whether it will help to improve the patient outcome. A radiological imaging requisition must specify the choice of investigation and the surgeon's expectations from it, so that the information received strengthens his approach in treating the patient.

It must provide mandatory demographic and relevant clinical data, including the patient's symptoms, which primarily brought him to the MFS, their duration, clinical signs, and the clinician's differential diagnosis of the same. In addition to concentrating on the clinical data, entries made available through the Hospital Information system (HIS) and the Radiology Information system (RIS), accurate patient identifcation by the MFS is essential prior to referral to the imaging department.

#### **8.3 Role of the Maxillofacial Surgeon (MFS) Vs. the Radiologist's expectation from the MFS**

An MFS deals with patients suffering from maxillofacial disease processes, but being a clinician primarily he is expected to have basic knowledge of various systemic clinical problems as well. Systemic disease may manifest as disease in the maxillofacial region or vice versa. For instance, a cystic lesion in the jaw could be the primary radiographic fnding in a patient suffering from hyperparathyroidism. Similarly, patients suffering from systemic diseases like osteopetrosis, fuorosis, fbrous dysplasia, and other marrow infltrative disorders could also present with a disease in the maxillofacial region. Further, detection of congenital anomalies in the maxillofacial region is an indication for a more detailed survey to rule out associated anomalies elsewhere.

The surgeon should be able to identify radiological images, correlate the same with the report and the patient's clinical status, and focus on timely decision making and patient management, thus optimizing the patient's outcome. However, in a dire emergency when a radiologist's opinion is not available, or a delay is expected in obtaining the same, an MFS should be able to interpret radiographs that suggest life-threatening conditions like tension pneumothorax, aspiration bronchopneumonia, foreign body aspiration, or pulmonary edema among others. Imaging can help the MFS in narrowing down on the clinical diagnosis, in staging and evaluating the prognosis of a disease process, or in surgical planning by depicting the exact extent of a lesion after diagnosis is confrmed.

MFS' need to communicate with their radiology counterparts the expectations they have from imaging of a case so that the radiologist can provide the relevant anatomical and functional information from the region of interest. Each imaging modality has its own reporting language and the surgeon needs to be well versed with the language used and have a clear concept of principles of image formation, specifc to the energy source used in the particular investigation.

#### **8.4 Role of the Department of Imaging and the Radiologist**

The responsibility of the imaging department is conducting the specifed diagnostic imaging investigation, interpretation of the tests or procedures by the radiologist and providing the clinician with accurate reports of the performed investigation as early as possible. Clinical radiologists function as key members of multidisciplinary teams, being an integral part of patient care.

#### **8.5 Energy Forms Used in Diagnostic Medical Imaging: Understanding the Basics**

Different types of energies are used in diagnostic imaging. These energies are imperceptible to the human eye and when they are passed to the desired location in the body, they interact with the body tissues in different ways. The tissue interactions can reveal information about the tissue, but they need to be interpreted. Access to this information is possible only if it is converted into a visible form on a display system. In essence, the requirements for an imaging investigation are; a reliable and reproducible energy form, a subject (the patient) into whom the energy can be sent, and a format that can convert the invisible image into a visible display.

X-rays and gamma rays are photon energies and members of the electromagnetic spectrum having a wide range of wavelengths and frequencies. X-rays have very small wavelengths being lesser than 1 Å unit and greater than 0.1 Å units. This range of specifc frequencies and wavelengths of X-rays give them special properties, gaining popularity in diagnostic imaging.

Gamma rays have shorter wavelengths and higher frequencies than X rays. They are used in nuclear medicine both for diagnostic and therapeutic purposes.

Conventional radiography, including mammography, fuoroscopy, computed tomography (CT), is a modality that generates images of the ionizing radiation. It works on the same basic principle, which essentially involves passing of an X-ray beam through the body followed by absorption and scattering of a portion of the X-ray energy by the body tissues and transmission of the resultant radiographic pattern formed by differential tissue absorption to a detector for recording or further computer processing.

The popularity of X-rays as an imaging modality is due to its optimum penetration power and photochemical and fuorescent properties. Its fuorescent property is useful in converting invisible images into visible light images, while the photochemical property is responsible for conversion of the visible light image into a permanent visible record called radiograph.

*Conventional radiography* includes plain radiographs of different body parts like chest, skull, PNS, etc., contrast studies of the gastrointestinal tract like Barium studies, contrast studies of the genitourinary tract like Intravenous urography (IVU), and contrast studies of the vascular system like Arteriography, Phlebography, etc.

*Fluoroscopy* involves a continuous display of real-time movements of moving structures as radiographic images on the monitor, e.g., act of swallowing, movement of the soft palate, movement of the temporomandibular joint, cardiac pulsations, diaphragmatic movements, etc.

*Computed Tomography* includes cross-sectional imaging with its modifcations like 3D, Volume rendering, Multiplanar reconstruction images, C.T. angiography, etc.

*Ultrasound* imaging or sonography makes use of highfrequency sound waves that are transmitted from the transducer into the body. The refection of these waves off the body structures forms the basis of ultrasound image formation. The information necessary for image production is provided by the amplitude of the refected sound signal and the time taken for it to travel through the body. Commonly ultrasound is used in the imaging of the abdomen, fetus, breast, eye, heart, vessels, and the musculoskeletal system. In recent years, there has been much research into ultrasound of the maxillofacial region, and it has been found to have a range of unique applications, including the evaluation of cervical lymph nodes and the detection of space infections and cystic and solid lesions of the head and neck. In early cases of peripherally located carcinoma of the tongue, ultrasonography may be an initial mode of imaging for evaluation.

Ultrasound imaging is not associated with the same risks as ionizing radiation and is considered to be generally safe if used appropriately. Ultrasound energy does have the potential to produce biological effects on the body and can cause minimal heating of tissues and in certain cases produce tiny gas pockets in the tissues and body fuids known as cavitation.

*Magnetic resonance* imaging makes use of strong magnetic felds and radiofrequency energy to create images. The signals that produce an MR image originate from the protons present in water and fat molecules in the body. Application of a strong magnetic feld by the MRI scanner causes the protons within the body to align themselves. Radiofrequency current is then passed into the patient's body creating a varying magnetic feld that causes the protons to fip their spins. Turning off the radiofrequency pulse causes the protons to return to their normal spins, producing radio signals that are measured by receivers in the scanner and used to make digital images of the scanned area of the body.

Many forms of MRI exist, diffusion and functional MRI being the most common. Diffusion MRI helps in diagnosing disease processes like stroke that restricts diffusion of water molecules across body tissues, while functional MRI is used to visualize the functional activity of the brain. MRI does not use ionizing radiation but since it uses strong magnets, any form of metal implants like artifcial joints and heart valves, pacemakers, cochlear implants, metal plates, screws, and rods do pose a hazard.

*Thermography* makes use of specialized cameras that can detect electromagnetic light energy in infrared wavelengths. Medical thermography produces a topographic heat map, displayed in the form of various color shades, based on the differential skin temperature at various dermatomes bearing resemblance to the visible image of the body. It is not a structural imaging technology providing information on structural changes like other modalities and does not provide a diagnosis, rather only aids in reaching a diagnosis. It is completely safe and painless, does not make use of any form of radiation, and is a unique form of imaging in that it can document pain, thus helping to differentiate malingering from an organic cause for the pain.

#### **8.6 Basic Radiology for the Nonradiologist: What the MFS should know?**

Plain radiographic flm interpretation is an essential skill. The current implementation of electronic health records and digitization of the health care system has made radiographic images available throughout the hospital and an MFS may often have to interpret medical images. So, it is important that they know the basics of medical image interpretation, and this knowledge may prove to be crucial in an acute clinical setting. They should be aware of tissue appearances on radiographs and be capable of making a basic distinction between normal and abnormal.

Understanding the concept of density and contrast is fundamental to interpreting an X-ray image (radiographic image). Different body tissues, including bone, soft tissues, fat, and air, all attenuate the X-ray beam differently. Differential absorption of X-ray photons by the body tissues results in variable energy values of emerging photons producing an invisible image, which is converted into visible form as areas of different gray scales. The contrast on the image is the difference between adjacent densities. These densities range from white to black with varying gray shades in between them. If the densities of two tissues adjacent to each other are greatly different (say a white and a black density tissue), then they are said to have high contrast. If the densities of two tissues adjacent to each other are similar, then they are said to have low contrast. They appear similar in color, differing in their shades of gray. When two body structures of identical density are exactly side by side, the line of demarcation cannot be made out and whole of it appears as one structure.

Consider a chest radiograph. What do you think is the whitest component seen on the radiograph? Most commonly the answers given are heart, bones, below the diaphragm, and so on. Rarely does anyone mention that the "R" marker is the whitest. Similarly, if asked which the darkest component is, the popular answer given is, the lung surrounding the heart, very rarely does one mention that the air surrounding the chest is the darkest. Analyzing as to why the "R" marker is white and the air surrounding is dark, the reasoning is that the chest radiograph is nothing but a representation of the tissues in that region in various gray scales between extreme white and extreme dark, depending upon the variable absorption of X-ray photons in their path through the tissues.

The opacity produced on a radiograph by a specifc body tissue is a representation of the actual penetrative ability of X-rays to pass through that tissue and then be incident on the flm. Air and fat absorb less radiation, allowing more X-rays to pass through and be incident on the radiograph making their images appear black and pale gray, respectively. Bone and metal as is the "R" marker made of lead absorbs more radiation and so fewer X-rays are incident on the flm making them appear white.

Continuing with the example of chest radiograph, what are branching structures that are seen in the lung felds? Are they arteries, veins, bronchi, lymphatics, or a combination of all these? The common answer given is bronchovascular. The correct answer is arteries and their branches, but not the bronchial tree. The explanation is simple. Air in the bronchi is surrounded by air in the alveoli and so no contrast exists between them and they are hence not seen. On the other hand, blood in the arteries is surrounded by air in the alveoli and hence they stand out. Veins do contain blood but are too less in number and do not signifcantly contribute to the branching structures. Lymphatics are too small to be detected.

If this basis of X-ray image formation is understood, you can easily interpret any radiographic image provided you have sound knowledge of the relevant anatomy, pathology, and pathophysiology.

#### **8.7 Imaging Investigations**

#### **8.7.1 Imaging Investigations Using Ionizing Radiation (Photon Energies)**

Electromagnetic radiation has a wide range of wavelengths ranging from being smaller than angstrom units to as large as many miles. Smaller wavelengths have greater energy and penetration power and are called photon energy meaning packets of energy and not particle energy. The two energies that are of concern in the present context are X-rays and Gamma rays. Passage of these energies through body tissues either for diagnostic or therapeutic purposes results in a series of events beginning with an incidence of the X-ray photon into tissue followed by sequential changes at molecular and atomic levels. The transformation of energy from the photon results in ionization, namely, in the discharge of an electron and a free radical. Hence, such energies are called ionizing radiation and the process involves breakage of enzyme bonds and formation of new molecules manifesting in the form of various repairable and irreparable biological effects.

The concept of photon energy and its effect on body tissues can be explained using the following example. Consider a hot iron ball being passed through a pile of corn (Fig. 8.1). The temperature of the ball after exiting the corn pile is grossly reduced. It is because the ball, during its transit through the pile, shares the energy with the corn in contact with it. The corn in very close contact to the ball is burnt to ashes, the corn a little farther away, is burnt to charcoal, corn still further away is converted to popcorn, while corn far away from the ball remains unaffected. The effect on the corn is directly proportional to the energy transferred from the hot iron ball to the corn. The same thing happens when photon energy passes through the body tissues with changes occurring at atomic level.

#### **8.7.1.1 X-Rays**

X-rays are a form of electromagnetic radiation. Man-made X-rays are produced when fast-moving electrons undergo sudden deceleration on collision and interaction with the target anode in an X-ray tube. The electrons are emitted by the cathode, on being heated up by the electric current fowing through it.

Though conventional X-ray imaging has evolved over the past 100 years, the basic principle remains the same. On passage of an X-ray beam through the body, the beam is attenuated by the body's internal structures, being partly absorbed and partly scattered. The remnant of the X-ray energy is transmitted to a detector that records the image for later evaluation. The recording of the radiographic pattern may be on flm or other electronic devices. The image created is due to weakening of the X-rays by tissues of varying density encountered along the beam's travel path. Bone being dense tissue, absorbs or attenuates a great deal of the X-rays, while soft tissue being much less dense attenuates or absorbs far less X-ray energy. These differences in absorption help in creating images that can clearly show normal tissue appearance as well as different forms of pathology.

Conventional radiography, fuoroscopy, and CT all work on the same basic principle differing only in their purpose. In radiography, a single image is recorded for later evaluation, in fuoroscopy X-ray images are displayed on a monitor in a continuous fow, thus allowing monitoring of a procedure or contrast passage in real time and in CT imaging a multitude of images are recorded as the detector rotates around the patient's body followed by reconstruction of the individual images as cross-sectional images of internal organs and tissues.

#### **8.7.1.2 Computerized Tomography (CT/Spiral CT)**

Computerized axial tomography is a computer-controlled radiological study that produces a reconstructed image of a cross-sectional slice of the desired section of the body. Its features include the absence of superimposition, less scatter and better tissue differentiation of the anatomical slice, thinner slices producing a better reconstructed image. The major drawback of conventional radiography is the overlapping of anatomical structures resulting in diffculty in evaluation of desired structures in a particular plane. The imaging method 'Tomography' was introduced to overcome this drawback and involves imaging of anatomical structures at the desired plane with the blurring of overlapping structures. Classical conventional tomography had its own inherent drawbacks, which included poor-quality blurred images, high radiation dosage, and use of complicated techniques which led to it being replaced by tomography assisted by computer technol-

**Fig. 8.1** Illustration of passing a hot iron ball through a pile of corn and its effect on the corn

ogy called 'Computer assisted Tomography' (CAT). With a rise in popularity, CAT has been replaced by the word C.T. and technological advances have resulted in the development of better equipment capable of scanning the entire body within a few seconds. This provides fne anatomical details of submillimetric structures, allows tracing of blood fow in all its phases, and also permits clear depiction of information related to moving structures like the heart in real time as well as their external and internal morphology. Two types of CT have been described based on the shape of the X-ray beam, the traditional fan beam CT and cone beam CT.

#### **CT Unit Components** (Fig. 8.2a, b)

The essential components of a CT unit include:


CT scans have many benefts that far outweigh their risk. It is quick and easy, widely available, and provides superior anatomic and bone details. It has Volume Rendering Technique (VRT), Maximum Intensity Projection (MIP), 3D and Shaded Surface Display (SSD) capabilities, provides multiplanar reconstruction images in desired planes, and is the modality of choice for follow-up studies. (Figs. 8.3a, b, 8.4a, b, 8.5a,b, 8.6a, b, 8.7a, b, 8.8a, b, 8.9a, b, 8.10, 8.11, and 8.12).

The possible risks of using CT imaging include exposure to ionizing radiation and the predicament of suffering an allergic reaction due to use of contrast media. One drawback of CT when compared to MRI is the lesser resolution of softtissue detail. Other disadvantages are the associated cost and the limitations of its use in the pediatric age group due to the need of sedation.

#### **CT Limitations**

Motion and beam-hardening artifacts used to be considered as major drawbacks, but they have been markedly minimized with advances in technology. A physical limitation is that the patient needs to weigh less than 300 to 400 lbs. For

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.2** (**a**) CT room shows Gantry, Patient couch, Emergency crash trolley, Central suction, and Oxygen and Pressure Injector. (**b**) Control room showing a CT technician working with various controls and the image acquisition system

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.3** (**a**) Museum Model of head showing how axial slices are planned. The slice thickness varies from submillimeter to 10 mm, depending on the ROI (region of interest) and anatomical structure to be seen. (**b**) Stacked CT slices showing specifc anatomy at a specifc slice

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.4** (**a**) CT axial primary slice soft-tissue window at the level of optic nerves showing mediolateral and anteroposterior relations and not supero inferior relations. (**b**) CT sagittal reconstructed image of the

same patient at the level of optic nerve showing anterior, posterior, superior, and inferior relations

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.5** (**a**) and (**b**).CT coronal bone window primary images at different levels of paranasal sinuses

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.6** (**a**) and (**b**).CT coronal soft-tissue window primary images at different levels of Paranasal sinuses

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.7** (**a**) and (**b**). CT reconstructed coronal images from thicker slices of paranasal sinuses at different levels. (**a**) bone window. (**b**) soft-tissue window. Note: coarse appearance

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.8** (**a**) CT direct slice of T.M. joint in its sagittal plane. Bone window. (**b**) CT reconstructed image from primary axial thick slices of T.M. joint in its sagittal plane. Note: coarse appearance

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.9** (**a**) CT 3D reconstructed image for surface bony details from thicker slices. Note: coarse appearance. (**b**) CT 3D reconstructed image from thin slices. Note: better and smoother image

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.10** CT 3D surface rendering reconstructed image for surface soft-tissue details from thinner slices

CT imaging of the head region, axial and direct coronal slices are primarily possible, for the neck region, only axial slices are possible and in the temporomandibular joint region axial and direct sagittal slices are possible. It is through the raw data thus available that images are reconstructed in any desired plane.

#### **Dentascan**

#### *Basic principles of CT Orthopantomography (OPG) and Dentascan*

Conventional OPG is a frst-level diagnostic exam that provides a gross panoramic view and just enough information about alignment of the teeth and any other related gross pathology. Unavoidable overlapping of some of the anatomical structures hinders accurate evaluation. To overcome these drawbacks, Dentascans and CT OPGs are used. They are extended applications of CT scan and involve the acquisition of thin axial submillimeter slices of the region covering the upper and lower jaws (Fig. 8.13). Reconstructed images obtained using these raw data image slices form the CT OPG or Dentascan image (Fig. 8.14a, b).

Coronal reconstructed images form the C.T. OPG (Fig. 8.15a, b, c). It is a second-level imaging technique wherein evaluation of the osseous elements of the maxilla and mandible is far better in comparison to conventional OPG. It provides the MFS with a better understanding of the morphology of the roots and the degree of contiguity between the roots and the mandibular canal. The information acquired is then used in planning and performing minimally invasive surgical procedures [1].

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**Fig. 8.11** (**a**) CT Primary axial slice of neck at midlaryngeal level. (**b**) and (**c**) Sagittal and coronal reconstructed images from sequential CT primary axial slices. (**d**) CT Volume rendering technique (VRT) image of air column in the pharynx, larynx, and tracheal region as minimum density projection from primary axial slices (**a**). Note: Better visualization of laryngocele

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**Fig. 8.12** CT angiogram: 3D VRT (Volume Rendering Technique) displaying carotid arteries and its branches along with carotid body tumor. It is a reconstructed image from primary thin axial CT slices

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**Fig. 8.13** CT Scanogram for dentascan showing submillimeter axial slices planning in the region of maxilla and mandible

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**Fig. 8.14** (**a**) and (**b**) .Reformatted panoramic CT images (**b**) are procured at desired plane of the jaw by curvilinear graphic lines drawn on the primary axial slice (**a**) selected

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**Fig. 8.15** (**a**)**,** (**b**), and (**c**). a and b show coronal plain image planning of individual tooth. c shows the coronal reformatted image of tooth

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**Fig. 8.16** (**a**) and (**b**). Schematic diagram. (**a**) shows fan beam of X-rays from X-ray tube with curvilinear row of detectors. (**b**) shows cone beam of X-rays from X-ray tube with fat detector

#### **Cone Beam CT (CBCT)**

#### *Indications for CBCT*

CBCT applications have proved helpful in a multitude of dental disciplines and the MFS needs to be aware of it. Its indications include periodontal and endodontic assessment, placement and evaluation of implants, evaluation of jaw bones, temporomandibular joints, bony and soft-tissue lesions, and alveolar ridge resorption and orthodontic evaluation.

#### **Working Principle and System Composition of CBCT System**

As the name suggests, it is a form of computed tomography (CT). The basic process involved in CBCT is the scanning of the region of interest using a cone-shaped X-ray beam, making a single rotation around the vertical axis of the patient's head. The information obtained, from various angles about the structures in the region of interest, is in a digitized format relating to shape and density, which is then processed using

**Table 8.1** Comparison between CBCT and Fan Beam CT


special software and a three-dimensional (3D) image is reconstructed [2].

CBCT occupies a special place in imaging of the Head and Neck region. It offers a number of advantages over traditional CT technology. It has a multitude of uses in the dental discipline, including dentoalveolar disease and anomalies, jaw tumors, vertical root and dentin fractures, among others. It has also had a positive impact on teaching students about oral and maxillofacial imaging making them adept at operating equipment and related instruments, resulting in greater accuracy in evaluation and analysis of the pathological characteristics of the disease process leading to a proper fnal clinical diagnosis. Both the traditional fan beam CT and CBCT are third-generation CT scanners but are different in some ways (Fig. 8.16a, b) (Table 8.1).

#### **8.7.1.3 Gamma Rays**

Gamma rays are a form of Electromagnetic radiation (EMR). They are similar to X-rays but can be differentiated by the fact that they originate from the nucleus. Gamma-ray photons have the highest energy with their waves having the shortest wavelength in the EMR spectrum. The difference between the two is that X-rays are produced by accelerating electrons when they strike a target, while gamma rays originate from the nucleus of a radionuclide after radioactive decay. Gamma rays damage the DNA of cells and it is this action that is used in the treatment of cancerous tumors, care being taken not to affect the DNA of the surrounding healthy tissue cells [3].

#### **8.7.1.4 Nuclear Isotope Studies**

Scintigraphy or radionuclide imaging is a modality that is readily available and relatively inexpensive. One drawback is that though it can provide specifc information, the resolution is poor. It is a functional imaging modality and can assess early physiological changes even before bone mineral changes are evident. Bone scintigraphy is highly sensitive in detection of skeletal osteoblastic activity and the process involves uptake of the radiopharmaceutical Technetium-99 m (Tc-99 m), by the mineral component of the bone due to its affnity for bone. It has proven to be greatly useful in the study of malignant lesions and also in the evaluation of vascularized bone grafts used in reconstruction surgeries of the maxillofacial region [4]. Another use of radionuclide imaging is in evaluating patients with condylar hyperplasia. In these patients, radionuclide imaging of the temporomandibular joint is performed to exclude active condylar growth and in planning the extent of orthognathic surgery. A progressive condition necessitates the removal of the entire condyle and neck while trimming of the enlarged condyle suffces otherwise [5].

#### **8.7.1.5 Positron Emission Tomography (PET)**

PET also is a functional imaging technique. It is unique in that it produces images refecting in vivo changes in tissue metabolism, linking the changes to malignancy. Body images are produced when radiation is emitted from radioactive tracer substances like Carbon-11, Fluorine-18, Oxygen-15, or Nitrogen-13. When a positron emitted from the radioactive substance collides with an electron in the tissue, gamma rays are given off at the site, which are detected by a gamma detector. FDG-PET/CT fusion scans of the head and neck are not primarily for infection identifcation but for categorizing a clinically questionable lesion as malignant or not.

CT scans detect changes in body structure and only confrms the presence of a mass. PET scan is different from CT in that it can reveal the presence of disease earlier allowing for quicker diagnosis, can detect the extent of disease and whether a detected mass is benign or malignant, helps monitoring treatment and its effectiveness, and can detect abnormalities even before there is any anatomical change. This is based on the fact that glucose consumption by malignant cells and hence tissue is far higher than that of normal tissue.

The scan involves intravenous injection of a radiolabeled compound like 2-deoxy-2-(18F) fuoro-D-glucose (FDG). After uptake of the compound, it undergoes further break down in the cells. Since tumor cells have a high metabolic rate, it is also metabolized by the tumor cells. FDG is metabolized to FDG-6-phosphate, but the tumor cells are incapable of metabolizing it further and in consequence the FDG-6 phosphate accumulates and concentrates within the tumor cells. It is this accumulation that is detected and quantifed. As compared to normal tissue, the uptake of FDG by malignant tissue is very high, making it a sensitive method to pick up early malignant tissue [6].

#### **8.8 Radiation: Hazard Awareness and Principles of Protection**

#### **Hazardous Nature of X-Rays**

When an X-ray photon is incident on tissue, it results in a series of changes at the molecular and atomic level. The transformed photon energy results in the discharge of an electron and a free radical, or ionization in other words. Ionization results in the production of a new molecule due to breakage of enzyme bonds manifesting in the form of different biological effects. These effects may be repairable when there is no appreciable damage, or irreparable when there is defnite occurrence of damage, the adverse effect being cumulative in nature.

**Myths and Facts about radiation in the feld of Diagnosis:** Many myths exist regarding radiation hazards associated with medical diagnostic imaging. Possible reasons for this are the available historical data, exaggerated social media reports, results of experimental studies and the complex nature of radiation biology making it diffcult to evaluate its mechanism of action. Historical data relates to the reports of visible radiation hazards from studies on victims of the Hiroshima/Nagasaki bomb explosion in 1945 who were followed up for 15-18years. Exaggerated reporting by social media about nuclear reactor accidents like that at Chernobyl add to the existing myths. The extremely short time for which radiation interacts with matter (10-5Sec) after absorption, makes it diffcult to study the complex nature of radiation biology. The biological process of cell death can take days to months, carcinogenesis can take years to occur while generations may pass before a mutational change is seen.

In reality, the dose of received radiation from man-made X-rays that exist today is minute, in comparison with the massive radiation exposure that occurred in the aforementioned examples. It is true that in the infant stage following discovery of X-rays and its use in diagnosis, visible radiation hazards did occur, which was due to ignorance in the understanding of its potential hazards and the use of crude equipment resulting in high amounts of radiation leak. With passage of time, we have learnt to put the benefts of X-rays to full use, concurrently taking proper precautions to protect ourselves from its hazardous effects. Over the years, improvements in diagnostic equipment using ionizing radiation have led to the production of newer equipment providing the best possible image quality with minimal radiation exposure and improved devices that are protective against radiation. Yet, the fact remains that the best method to reduce the effects of radiation is using it only when it is an utmost necessity [7].

#### **8.9 Imaging Investigations Not Involving Ionizing Radiation**

#### **8.9.1 MRI (Magnetic Energy Coupled with Radiofrequency Energy)**

This imaging modality does not involve the use of ionizing radiation but makes use of magnetic and radiofrequency energy to obtain information of the internal organs. Components of an MRI unit include the magnet, the console, and the computer.

#### **Image Procurement by MRI**

Exploiting the body's magnetic property forms the basis of imaging using magnetic resonance. The human body is abundant in atoms with odd number of protons, or in other words ionized particles or charged atoms. A charged particle spinning around its own axis creates a magnetic feld around itself behaving like a tiny bar magnet. Hydrogen represents one such atom that is present in water molecules and therefore in all body tissues.

The random orientation of the hydrogen atoms cancels out their magnetic felds and so there is no net magnetization at rest. When these protons are placed in a strong magnetic feld, a net magnetization is produced that aligns parallel with the main magnetic feld. To infuence the human body, the external magnetic strength needs to be about 6000 to 80,000 times the earth's magnetic strength. The resultant net magnetization acts as the source of the MR signal and is used to produce MR images. Application of a radiofrequency (RF) pulse results in absorption of energy from the RF pulse causing the net magnetization to rotate away from the direction of the main magnetic feld, the amount of rotation or fip angle depending on the strength and duration of the RF pulse. The strength and duration of the RF pulse can be controlled such that the net magnetization can be rotated to any angle [8]. Withdrawal of the RF pulse results in the liberation of energy, with the emission of signals based on the density of protons or hydrogen atoms. These signals are captured by the external antennae, fed into the computer, and processed to produce the image.

#### **Types of Magnets: Their Advantages and Limitations**


#### **Preparing a Patient for an MRI**


CT & MRI are complementary to each other. As far as the MFS is concerned, thin-slice CT with reconstruction is required while evaluating bony lesions, especially in cases of trauma. MRI on the other hand is good for evaluation of softtissue tumors and is contraindicated in penetrating injuries of the eye (Table 8.2).

#### **Table 8.2** CT and MRI: A comparison


#### **How Does CT/MRI Differ from Conventional Radiography?**

CT and MRI are sectional imaging methods, in which the whole body or the region of interest is sectioned into serial slices and further into cubes (Fig. 8.3a, b). Each slice surface represents the corresponding sectional anatomy with each slice being made up of small units or cubes with each cube representing the basic nature of the tissue in the digital form (Figs. 8.17 and 8.18a, b). Different modalities produce varied imaging appearances of the same structure. For instance, if a coconut is imaged using different modalities, the fne structural details of the interior of the tender coconut, and its contents are better seen on CT and MRI (Fig. 8.19a-c). Similarly, imaging of a pineapple in axial (Fig. 8.20a-d) and coronal planes (Fig. 8.21a-c) and using the volume-rendering technique (Fig. 8.22) reveals varied appearances on CT and different MRI sequences.

To summarize, in sectional imaging, the region of interest or the whole body is divided into slices and cubes with each cube representing the basic tissue of that region with thinner slices and smaller-sized cubes offering better resolution.

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**Fig. 8.17** Each axial slice is divided into small cubes loaded with digitalized values representing corresponding tissue volume called voxel. Its surface represents a fraction of the grayscale image specifc for that region called pixel. Thinner the slice and smaller the pixel, better is the resolution

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**Fig. 8.18** (**a**) and (**b**). Figures showing unit wise volumetric digitalized information of anatomical structures for retrieval and displayed as sectional anatomical slices

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**Fig. 8.19** (**a**)**,** (**b**), and (**c**). Imaging of tender coconut. (**a**) Conventional plain Radiograph. (**b**) CT Axial sectional imaging. (**c**) MRI sectional imaging. Note: added information with each of these modalities

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.20** (**a**)**,** (**b**)**,** (**c**), and (**d**). Axial sectional images of pineapple taken at the same level (**a**) CT. (**b**, **c**, **d**) MRI various sequences. Note: superior soft-tissue resolution in MRI, highlighting various components of soft tissue in various sequences

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**Fig. 8.21** (**a**, **b** and **c**). Various sequences of MRI of a pineapple showing multiplanar capability to procure sections in any desired plane without reconstruction unlike CT

©Association of Oral and Maxillofacial Surgeons of India

#### **8.9.2 Ultrasound**

It seems implausible that sound waves can produce informative images of internal organs of a human body. Yet it is true that technology has evolved so much over the years that it is now possible to obtain information of body structures using sound waves by making use of the echo and Doppler properties of sound waves.

Sound waves can be classifed, based on their wavelength and frequency as audible sounds (20 to 2000 cycles/sec), infrasound (less than 20 cycles/sec), and ultrasound (>20,000 cycles/sec). Ultrasound in the range of 2 to 20 MHz is used in medical imaging [8]. The source of these ultrasound waves is piezoelectric crystals. These crystals have the special property of generating electrical pulses on being subjected to pressure. In addition, the passage of electricity through the crystals causes them to get compressed or deformed. Essentially, these crystals are unique in that they have the dual property of converting electrical energy into mechanical energy and mechanical energy into electrical energy. Intermittent passage of electrical current through the crystals makes them alternate between compression and relaxation, resulting in vibration of the crystal, in consequence producing sound energy of small wavelength in the ultrasound range.

Devices, equipped with piezoelectric crystals, having the capability to convert electrical energy to mechanical energy and fnally to sound energy as well as having the reverse capabilities of converting sound energy to electrical energy, are termed as Transducers.

Sound waves are useful in imaging due to their property of echo/refection and due to the Doppler effect. Echo property refers to the property of sound waves to get refected at the interface of two media, the strength of the refected sound echo depending on the density difference of the media through which they traverse. Refected sound energy gets converted to mechanical energy and fnally to electrical energy on striking the crystal, and this electrical energy is represented on a monitor as bright dots of variable gray scales.

Varying density interfaces throughout body tissues, produces variable image brightness with gray scales ranging between extreme bright dots to black dots, representing different organ or tissue sections. The Doppler effect of sound refers to the change in the apparent frequency of a wave when the observer and the source move toward or away from each other. Motion causes a change in pitch with a higher frequency being heard when the sound source approaches the observer, and a lower frequency being heard when the sound source moves away. This Doppler property is used in evaluating the direction and velocity of fow of blood in vessels. The transducer is considered as the fxed source of sound and the blood component, mainly the RBCs act as moving refecting bodies. At a given point in the vessel by calculating the sudden change in the frequency of refected sound, we can calculate the velocity of blood and also the direction of blood fow. This helps in the evaluation of percentage of stenosis in a vessel.

#### **B Mode**

A grayscale sectional image has specifc echo texture based on tissue content with the display mode being called as the 'B' mode (Brightness mode) or grayscale mode. Higher sound frequency provides better image resolution with delineation of fner tissue components, however, at the expense of depth of penetration. Higher-frequency transducers (7 MHz to 20 MHz) are hence used for imaging superfcial structures like cheek, the maxillofacial region, neck spaces, breast, thyroid, testis, eye, musculoskeletal system and skin, regions where fner analysis of tissue structure is expected. Deeper structures are evaluated by using transducers with frequency in the range of 2 to 5 MHz.

The relation between frequency, resolution, and depth can be understood well, using the hypothetical example of two friends—an ant and an elephant (Fig. 8.23a, b). Both of them are commanded to perform the same tasks, the frst being to pick up and bring back a crystal of sugar dropped at a distance of 100 cm from the start line and the second to pick up and bring back a log of wood placed 100 meters from the start line. Both of them proceed to perform the frst task. The ant being small is able to easily identify the sugar crystal and get it back; however, the elephant keeps moving around unable to identify the crystal. As to the second task, the ant is able to travel only a short distance after which it dies of exhaustion, unable to reach the log of wood while the elephant travels the distance with ease and brings back the log of wood.

The ant is comparable to the high-frequency shortwavelength sound wave that is able to travel a short distance and bring back fner information about superfcial tissues. If, on the other hand, it travels a long distance all its energy is absorbed by interaction with tissues. The elephant is comparable to the low-frequency sound wave with long wavelength that can travel deeper into the tissues and get information of deep structures, but limited tissue details. In a clinical setup, both the ant (high-frequency sound) and the elephant (lowfrequency sound) are essential for evaluation, depending on the clinical situation and region of interest.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.23** (**a**) and (**b**). Example of an elephant and an ant demonstrating their varying capability in picking up large and small objects from varying distances—a pictorial representation for understanding the dif-

ference in the penetration capacity of high- and low-frequency sound waves. (Explained in the text)

#### **Color Doppler**

The display of fow of blood in a vessel is color coded. The fow toward the probe is depicted as red and fow away from the probe is blue. Arterial and venous fow, in a given anatomical region, is in opposite directions. Red generally represents fow in arteries, while blue represents venous fow. Turbulent fow is depicted using a mixture of colors.

#### **Power Doppler**

This display mode of Doppler conveys information about the overall fow in a given tissue, for instance, assessment of blood fow in a tumor. It helps to determine whether the tumor is hyper- or hypovascular.

#### **Strengths of Ultrasound**


#### **Weaknesses of Ultrasound**

• A long learning curve exists for some areas of expertise and image resolution is dependent on the machine that is available. Ultrasound does not give information of structure behind a bone and also gas flled structures.

#### **Specifc Role of High-Resolution Ultrasonography (HRUSG) in the Maxillofacial Region**

HRUSG is a grossly underutilized modality in evaluating lesions of the maxillofacial region. This is due to the lack of awareness of its application. The tissues in the maxillofacial region are ideal for sonographic evaluation and hence is widely applied to help diagnose a number of clinical conditions. It can serve as the best possible initial parallel imaging investigation for all the superfcial soft-tissue structures of head and neck region.

It is noninvasive and does not involve use of radiation. There are no contraindications to the use of ultrasound, and it can even be performed as a bed side examination. No prior specifc preparation is required except for shaving of the beard, which might hamper the study. The study results are immediately available, and it is an excellent modality for evaluating various soft-tissue planes of the cheek. Evaluation of various anatomical spaces such as superfcial masticator space, parotid space, carotid space, superfcial neck spaces, visceral space, foor of the mouth, and all the infrahyoid neck spaces like the submandibular and sublingual spaces are possible using HRUSG, as are also pathologies like pre- and paravertebral abscesses, cellulitis, Ludwig's angina, and ranula [9].

High-resolution ultrasound is also capable of evaluating the nature of lymph nodes, assessing fuid and solid components and also assessing tissue vitality. Procedures like drainage of abscesses and biopsies can be conveniently performed under ultrasound guidance. Being a highly economical imaging modality, it is excellent for follow-up studies, excellent as a screening method, and at most times proves to be the conclusive examination [9].

#### **Drawbacks of Ultrasound Examination of the Maxillofacial Region**

Drawbacks include diffculty in assessing structures behind bony elements and structures containing gas. In case of huge masses, only partial information may be obtained, while shortnecked individuals and obese patients are diffcult to evaluate. Structures at the base of the skull cannot be evaluated as are structures medial to ramus. Another limitation is that ultrasound cannot provide information about structures behind bone or any gas-flled structure. Scanning using a hockey stick probe might help overcoming this limitation. Scans need to be performed by individuals having vast experience and expertise.

There needs to be an increase in awareness regarding the developments in the application of HRUSG in the maxillofacial region and a close interaction between the surgeon and the sonologist for creating an atmosphere of better understanding among them.

#### **8.9.3 Thermography**

Medical thermography is used for early preclinical diagnosis and treatment of homeostatic imbalances. It is noninvasive and safe since it does not use any radiation. It makes use of body heat to diagnose a wide range of health conditions. By using high-speed computers and thermal imaging cameras, body heat is processed and recorded in the computer as an image map that can be analyzed. The analysis is based on determining the presence of abnormal hot and cold areas that can relate to different conditions.

#### **Applications in the Maxillofacial Region**

A variety of conditions related to blood fow in the head and neck vessels can be assessed by thermal imaging. Easy visualization of facial blood vessels by thermography is possible because of its superfcial location. Common venues of thermographic use in the head and neck region include evaluation of pain related to differentiation of different types of headache, facial nerve injury following a blow to the face or an accident, and visualization of disorders of the temporomandibular joint.

### **8.10 Role of Chest Radiograph in the Practice of Maxillo Facial Surgery**

One of the most frequently requested investigations by an MFS is the Chest radiograph. Hence, interpretation of chest radiographic fndings is of prime importance in determining the patient's clinical status.

#### **8.10.1 Chest Radiographic Evaluation for Optimum Diagnostic Quality**

An ideal chest radiograph, in terms of quality, is one that fulflls the following criteria (Fig. 8.24)

	- *Purpose*—Avoiding problems related to improper positioning that can obscure certain lung regions like the hila and mediastinal lines, can prevent clarity of borders, or can result in distorted position of structures like the trachea, which can be misinterpreted as a paratracheal mass.
	- *Ideal radiograph*—The vertebral spinous processes are equidistant from the medial ends of the clavicle
	- *Purpose*—avoids superimposition of scapulae over the lung felds
	- *Ideal radiograph*—Medial border of the scapulae should be out of the lung feld
	- *Purpose*—inclusion of entire lung felds from apex to diaphragmatic domes
	- *Ideal radiograph*—must include the lower neck, both shoulders, lateral chest walls, and both diaphragms, including upper abdomen
	- *Purpose*—Proper patient and radiographic verifcation.
	- *Ideal radiograph*—must include the patient name, medical record number, date of acquisition, and the side marker (the most important of all)
	- *Purpose*—Clear visualization of the normal anatomy or presence of any pathology
	- *Ideal radiograph*
		- Posterior third of ribs faintly visible through heart shadow
		- Intervertebral spaces faintly visible through the heart shadow
		- Obtained in deep inspiratory effort as revealed by position of diaphragms

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**Fig. 8.24** A Normal Chest Radiograph

### **8.10.2 Reading a Chest Radiograph: Interpretation Basics**

The aim of reading a chest radiograph is to scan the whole image in a methodical way such that no anatomical part included in the radiograph is missed. While interpreting the radiograph, it is necessary for the interpreter to actually feel the structural component of the anatomical part being evaluated.

If, for example, a rib is being evaluated it needs to be traced, consciously keeping in mind, its component parts, the two cortical margins seen as white lines representing compact bone and the less dense central component representing marrow with fne normal trabeculae. This is in addition to evaluation of its number and shape. This meticulous evaluation will prevent missing of rib lesions and interpretation of the lesion is easier with prior knowledge of possible pathologies that affect ribs.

Many ways of methodical scanning have been documented in literature. The WHO-recommended method involves chest radiographic evaluation by beginning at one corner of the flm, continuing to horizontally scan till the other corner, followed by sliding down and again continuing to scan toward the other edge, continuing till the whole of the radiograph has been scanned. As part of the examination, both sides of the chest must be compared.

It can be likened to the painting of a wall by a professional painter with a perfect fnishing touch. Once the initial primary scan is complete, specifc areas called the lawyer's zone or hidden areas of the lung need to be looked over a second time. These areas include both the hilar regions, both cardiophrenic regions, both apical and clavicular regions, and fnally also through the heart and diaphragms.

#### **8.10.3 Requesting a Chest Radiograph: Clinical indications**

#### **8.10.3.1 Preoperative evaluation**


#### **8.10.3.2 Intra- / Postoperative recovery room**


#### **8.10.4 "The Chest Radiograph. A Mysterious Treasure"…the More you Search, the More you Find!!**

#### **8.10.4.1 Consolidation**

It is one of the most common terminologies used in Radiology. Clinicians and pathology textbooks, however, commonly use the term pneumonia. Any infection of the lung parenchyma is broadly referred to as pneumonia. Involvement of the alveolar components of the lung parenchyma by the infection is called parenchymal consolidation [10]. It is a disease process in which the air normally present within the small lung air sacs (alveoli) is replaced by liquids like pus, blood, or other fuids, or solids like tumor cells.

Radiologically, consolidation appears opaque [11]. Normally, the alveoli are flled with air and so the normal opaque pulmonary vasculature can be visualized against the dark background of air. However, as discussed earlier, the replacement of the air spaces by any form of fuid or solid material makes the normally visualized pulmonary vessels inapparent with the air containing bronchi being visualized against the opaque background, which is called the air bronchogram (Fig. 8.25a–c).

The consolidation process involving a single lobe and limited by a fssure is called as lobar pneumonia, while the involvement of the entire lung is known as whole-lung consolidation. At times, the process is not as uniform and is distributed in the form of patchy opacities with intervening nonopacifed alveoli, an appearance referred to as the air alveologram, which is seen in Bronchopneumonia.

#### **Pulmonary Edema**

Maxillofacial surgeons are often faced with the problem of patients going into a state of sudden breathlessness in the postoperative recovery room for which the MFS asks for a portable chest radiograph. One of the most common causes of sudden breathlessness in the postoperative recovery room is pulmonary edema. The common confusion for which MFS postgraduates seek the radiologist's opinion is whether the cause of breathlessness is bronchopneumonia or aspiration bronchopneumonia.

In case of acute cardiogenic pulmonary edema caused either due to left ventricular failure or fuid overload, the characteristic radiographic abnormality would reveal bilateral symmetrical areas of consolidation predominantly in the

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**Fig. 8.25** (**a**) and (**b**) Consolidation: Homogeneous opacities with "Air-bronchogram" sign. (**c**) Schematic diagram showing group of alveoli flled with fuid replacing normal air

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**Fig. 8.26** (**a**) Congestive cardiac failure with cardiomegaly and pulmonary edema. (**b**) Resolution of pulmonary edema after treatment

perihilar and lower lung zones [10] (Fig. 8.26a, b). Noncardiogenic pulmonary edema caused by different pathologies, including fuid overload, acute glomerulonephritis and adult respiratory distress syndrome among others, affects the permeability of the pulmonary capillary membrane (Fig. 8.27). The distribution can vary depending on the position of the patient. The opacities seen on the portable radiograph should not be confused with the appearance of pneumonia (Fig. 8.28).

Rare causes of unilateral pulmonary edema, including raised intracranial pressure and the administration of fuid through the central venous catheter inadvertently placed in the pulmonary artery, need to be kept in mind as well.

#### **Atelectasis**

Diminished air within the lung associated with reduced lung volume is termed atelectasis manifesting radiologically as pulmonary opacity accompanied by volume loss. The causes are varied, including resorption, relaxation, adhesive and cicatrization atelectasis. Of these, the form of atelectasis a maxillofacial surgeon commonly deals with is resorption atelectasis, where there is an obstruction in the communication between the alveoli and trachea. The obstruction may be at any level from the common air way to the segmental bronchus; however, common air way obstruction resulting in bilateral atelectasis is a rare occurrence [11]. Radiologically, the appearance is that of a homogeneous opacity without an air bronchogram sign, with loss of lung volume and displacement of structures toward the opacity.

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**Fig. 8.27** Noncardiac pulmonary edema in a patient with renal failure

The maxillofacial surgeon commonly comes across similar radiographs in the postoperative recovery room. The commonest cause of this is the inadvertent placement of the endotracheal tube into one bronchus, causing occlusion of the other bronchus, and resulting in atelectasis as a

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.28** Aspiration Bronchopneumonia

consequence. Early detection and diagnosis with readjustment of the endotracheal tube is bound to be life saving, helping prevent long-term complications (Fig. 8.29a–c). Thick mucus plugs are other common occluding elements, seen in postoperative recovery rooms resulting in lobar or segmental opacities with loss of volume. Again, early detection and good respiratory physiotherapy are keys to improved lung compliance with a radiograph taken at a later date as follow-up.

#### **Relaxation Atelectasis**

Normally negative intrapleural pressure is caused by competing thoracic pressures. Lung elasticity and surface tension of the alveolar fuid create an inward tension, pulling the lung inward, which is countered by opposing forces from the pleural fuid and thoracic wall, the pleural cavity surface tension, and the parietal pleural attachment to the thoracic wall causing outward pull of the lungs. The outward pull is slightly higher than the inward pull with a negative intrapleural pressure of about -4 mm of Hg. When this intrapleural negative pressure is lost as occurs commonly in cases of pneumothorax or pleural effusion, the lung has a natural tendency to recoil, with the loss of lung volume being proportional to the amount of air or fuid collected in the pleural space [11].

#### **Pneumothorax**

The presence of air in the pleural space is called pneumothorax, the most common cause of which is trauma either accidental or iatrogenic. In the absence of such causes, it is called spontaneous pneumothorax. Radiological fndings of pneumothorax include increased peripheral translucency, absence of lung markings within this area of translucency, and the identifable visceral pleural margin of the collapsed lung (Figs. 8.30 and 8.31). The detection of a pneumothorax should prompt the search for an underlying cause like a fractured rib or a ruptured bulla or iatrogenic causes like a central venous catheter procedure. Associated lesions like pneumomediastinum and surgical emphysema should also be looked for.

A maxillofacial surgeon might have to read supine portable radiographs of patients presenting with clinical signs suggesting respiratory distress and the presence of pneumothorax might be missed. In such a scenario, the MFS should look for radiographic evidence of pneumothorax at sites adjacent to the diaphragmatic silhouettes on either side and the cardiophrenic and costophrenic angles and he should also be able to appreciate the appearance of an exceptionally sharp cardiac border [11]. The MFS needs to be aware that air trapped within the skin folds can mimic pneumothorax (Fig. 8.32).

Identifcation of an air fuid level would prompt the diagnosis of a hydropneumothorax. It is diffcult to characterize the nature of the fuid as being transudate, exudate, blood, or chylous. An MFS may be unable to diagnose a hydropneumothorax, on an AP supine portable radiograph as the fuid level will not be identifed. Here, the collapsed lung tends to foat on the fuid, which is dependent posteriorly giving a veil effect (Fig. 8.33).

#### **Pneumomediastinum**

It is the collection of air within the pleural boundaries of the mediastinum and can arise secondary to barotrauma from mechanical trauma, intrathoracic, or iatrogenic trauma and infection or can occur spontaneously. A radiographic diagnosis of pneumomediastinum requires depiction of normal anatomic structures being outlined by air as they leave the mediastinum. The mediastinal air can cause elevation of the thymus, collect anterior or posterior to the pericardium, surround the pulmonary artery or its branches, or can collect adjacent to the major aortic branches or major bronchi (Fig. 8.34).

Most cases of pneumomediastinum described in maxillofacial surgery literature are as a result of dissection of air down the fascial planes of the neck. Chest radiographic fndings need to be carefully examined to make the diagnosis of pneumomediastinum, which is crucial to the MFS in planning appropriate treatment of affected patients. On rare occasions, a signifcant amount of air in the mediastinum can cause vessel or tracheal obstruction and induce symptoms and signs of tamponade and decreased venous return.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.29** (**a**) Whole lung collapse: Left hemithorax is homogenously opaque with loss of volume of left lung with displacement of mediastinum to left. Note: Abnormal placement of endotracheal tube blocking the (Lt.) Bronchus. (**b**) Schematic diagram showing loss of volume of alveoli as seen in collapse with absence of air. (**c**) Reversion of normal left lung aeration after repositioning of endotracheal tube

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.30** Left-sided pneumothorax

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.32** Right-sided pseudopneumothorax due to air trapped in skin fold

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.31** Right-sided tension pneumothorax

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.33** Right-sided hemopneumothorax with multiple rib fractures as seen in supine radiograph

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.35** (**a**) and (**b**). Surgical emphysema with

pneumothorax

**Fig. 8.34** Pneumomediastinum. Air around the pulmonary artery and heart.

#### **Surgical Emphysema**

Though subcutaneous emphysema or surgical emphysema actually means gas in the subcutaneous tissues, it also includes soft-tissue emphysema that dissects into the deeper soft tissues and musculature along fascial planes. The translucent air spreads over the chest wall and axilla into the root of the neck. Fascial planes clearly outline the pectoralis muscle and neurovascular bundles in neck (Fig. 8.35a, b). If trauma is the cause, the gas by itself may not need treatment, but its identifcation is of importance as it may be the only indication of the presence of other serious injuries requiring urgent management. Surgical emphysema can uncommonly occur as a serious complication of oral and maxillofacial surgical procedures. It may also occur following teeth extraction, endodontic treatment, or procedures like restorative dentistry, periodontal and temporomandibular joint surgery, or facial fracture repair.

#### **Pulmonary Nodules**

For all intents and purposes, a nodule seen in the lung (especially in the lower zones) should be considered as metastasis unless proven otherwise, by a maxillofacial surgeon.

©Association of Oral and Maxillofacial Surgeons of India

*Pulmonary nodules* can be characterized, based on some signature fndings. In the absence of these fndings, the nodule remains nonspecifc. Common causes of pulmonary nodules are granulomas, bronchogenic cysts, hydatid cysts, hamartomas, pulmonary hematoma following laceration, rheumatoid nodules, fungal granulomas, and pulmonary metastasis.

*Tuberculomas* usually range in size from 1 to 3 cm in diameter, have central calcifc lesions, and are surrounded by satellite scarred lesions. They are commonly seen in the upper zones, but they can occur anywhere in the lung (Fig. 8.36).

*Bronchogenic cysts* are well-defned nodules, around 3 to 4 cm in size, usually seen in the parahilar region, and are sometimes purely in the mediastinum (Fig. 8.37a–e).

*Hamartomas* are nodules that can occur anywhere in the lung having well-defned margins with central popcorn-like calcifcation (Fig. 8.38a, b).

*Hydatid cysts*, too, can occur anywhere in the lung. They have a stenciled outline and vary in size from 1 to 10 cms. The radiographic air crescentic sign is pathognomonic of a hydatid cyst, appearing like the arc of the moon caused by the separation of the endocyst from the exocyst. Continued separation of the endocyst from the exocyst results in an air fuid level typically called the 'water lily' appearance. Pulmonary hydatid cysts do not calcify.

Presence of a solitary nodule in the lower lung without any characteristic fndings makes pulmonary metastasis a strong possibility, which should be further evaluated with imaging and HPR. Multiple nodules of varying sizes in the lower zones are very much suggestive of pulmonary metastasis.(Fig. 8.39a, b).

#### **Role of Chest Radiograph in Cases Developing Sudden Onset of Breathlessness in Postoperative Period**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.36** Pulmonary Nodule—Tuberculoma

A maxillofacial surgeon should be capable of identifying all of these causes of sudden onset of breathlessness in a postoperative patient in the event of the absence of availability of expert radiological opinion and act accordingly. They also need to be aware that patients on ventilators may develop ventilator-dependent complications.

#### **A glance into the future of imaging for Maxillofacial Surgeons**

	- This is a modifed MRI study that helps in
	- Prediction of whether the primary tumor is benign or malignant (possible in 80 to 90% cases).
	- Differentiation of reactive versus malignant adenopathy.

This modality is still in the preliminary stage and needs further study.


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.37** (**a**), (**b**), and (**c**). Preop chest radiographs of a patient with cleft lip presenting with dyspnea, more with changing position. (**d**) **and** (**e**) Mediastinal mass—Bronchogenic Cyst confrmed on CT

**Fig. 8.38** (**a**) Pulmonary Nodule-Hamartoma. (**b**) Confrmed on CT

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.39** (**a**) and (**b**). Pulmonary metastasis

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.40** (**a**), (**b**), and (**c**). Foreign body, a coin in the cervical esophagus

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.41** Abnormal placement of endotracheal tube with collapse of left lobe

#### **8.11 Role of High Resolution Ultrasonography (HRUSG) as a Diagnostic Aid in the Practice of Maxillofacial Surgery**

#### **8.11.1 Preface**

Primarily the use of HRUSG in the maxillofacial region is directed toward investigation of the cheek and the structures adjacent to it. Despite the layers of the cheek and the adjacent structures having a classical sonographic appearance, literature available on HRUSG of the cheek is limited. Having proper understanding of the relevant anatomy is critical in discerning the wide range of diseases affecting this region. Evaluation of these lesions by ultrasound is possible only once the normal ultrasound anatomy at various levels is defned and a comparison of the suspicious lesion with the normal expected appearance is made. An original attempt toward this goal was made at our institute with comparison of normal cadaveric sections at corresponding levels taken by HRUSG.

High-resolution ultrasonography has broad applications in the maxillofacial region especially in the cheek, which include evaluations of the unilateral or bilateral swollen cheek painful or pain less, restricted mouth opening, painful chewing without obvious clinical fndings, and varied causes of facial swelling. Since early detection decisively infuences patient prognosis in case of malignancy, it is one of the prime concerns in a presenting patient. Further, differentiation of lesions as being of benign, malignant, infective, or infammatory etiology is important in deciding on a treatment plan. HRUSG should however be used to complement and not replace other imaging modalities as it does have its limitations.

Compared to other facial components, the cheek is predominantly composed of adipose tissue and is relatively small in size. Swelling of the cheek is easily visible and palpable in most patients presenting with cheek masses. Most lesions have nonspecifc characteristics on computed tomography (CT) and magnetic resonance imaging (MRI). In contrast, HRUSG is ideal for evaluation of cheek lesions, because of its capability to differentiate between tissues like skin, fat, muscle, gland, ducts, and vessels especially since bony and gaseous interfaces are absent. Further, the superfcial location of the cheek makes it easily accessible to ultrasound. Vestibule can be evaluated with fruit jelly technique obliterating the void space.

This short review attempts to aid the MFS in his understanding of HRUSG of the maxillofacial region, with special reference to the cheek.

#### **8.11.2 Gross Cheek Anatomy**

In simple terms, the cheek is the feshy portion of the face, below the eye, extending from the angle of the mouth to the ear. Anatomically, it pertains to the buccomasseteric region comprising the buccal space and its contents, masseteric and buccinator muscles, the buccal fat pad, and Stenson's duct.

The region is continuous anteriorly with the lips. Its external anterior demarcation is formed by the nasolabial fold and groove extending from the side of the nose to the angle of the mouth. The mucosa lining the inner aspect of the cheek adheres to the buccinator muscle, while the gingival mucosa covers the mandibular and maxillary alveolar processes. The gingivobuccal sulcus is the junction formed between the gingival and buccal mucosae. The vestibule is the region of the mouth between the teeth, lips, and cheek, which is bound superiorly and inferiorly by buccal mucosal refections onto the mandible and maxilla. Posteriorly the vestibule is continuous with the oral cavity proper (Fig. 8.42) [12, 13].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.42** Anatomical layers of the cheek

#### **8.11.3 Floor of Mouth, Anatomy (Relevant to HRUSG)**

The part of the oral cavity located underneath the tongue is called the foor of the mouth and it can be involved by a myriad of pathological processes. Superfcial lesions involving the mucosal surface are easily visualized and may not need imaging. Disease involving the deeper structures of the foor needs to be evaluated by imaging, and HRUSG is many times the frst line of investigation because of its superior soft-tissue differentiation capability, thus allowing for clear depiction of contents of the foor [14].

Infammatory processes, malignancies, and vascular abnormalities can affect the foor contents, while certain conditions like ranula and obstruction of the submandibular gland are specifc to this location [14].

### **8.11.4 Defning the HRUSG Anatomy of Maxillofacial Region (Predominantly Cheek)**

#### **Normal Ultrasound Cheek**

Various cheek layers have varying sonographic echogenicity and echotexture, and hence ultrasound is an invaluable tool in the characterization and localization of cheek lesions.

Depending on tissue density, the sound wave transmission, absorption, or refection capability of each tissue varies. Tissues, having high water content like blood, appear black and are called anechoic because they conduct sound waves well. In contrast, tissues that are poor conductors refect most of the sound wave energy back to the transducer appearing bright and are termed hyperechoic, examples of which include bones, tendons, and fascial planes. Tissues like muscle refect less of the sound wave energy and have a hypoechoic appearance. In the cheek, the mucosal and submucosal layers appear hyperechoic, the mucosa more so. Muscle tissue appears hypoechoic, while fatty tissue appears echogenic (Fig. 8.43).

Compared to other imaging modalities, ultrasound has proven to be superior as regards identifcation of small lesions, detection of lesion plane, and lesion characterization (Fig. 8.44).

The cheek layers and neighboring structures that can be identifed by HRUSG are.

#### **Cheek**


**Fig. 8.43** Normal Cheek/ Buccal layers on ultrasound


#### **Neighboring Structures**


#### **8.11.5 Techniques of HRUSG of Cheek**

For ultrasound examination, the cheek is considered to be a rectangular area bordered as follows (Fig. 8.45).


Various techniques, including the resting (neutral) and Puffed (Blow out) cheek technique, the tongue touch technique, and fruit jelly technique, were experimented with, each having their own advantages and limitations [15].

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.44** (**a**-**d**) Cheek anatomy—a comparison. Comparative cheek anatomy- (**a**) cadaveric specimen, (**b**) CT, (**c**) MRI, and (**d**) Ultrasound

©Association of Oral and Maxillofacial Surgeons of India

#### **Fig. 8.45** Area of Cheek ultrasound study

	- Patient is instructed to blow, and ultrasound is performed in puffed cheek status.
	- Images obtained in axial and coronal planes. Advantage: Improved visibility of cheek layers and accurate defnition of lesion size.

Limitation: Occurrence of mirror image artifact. Less sensitivity in evaluation of lesions of the vestibule (gingivobuccal sulcus).

	- Patient is instructed to feel the cheek lesion with the tongue.
	- Lesion is brought closer to the probe creating a better acoustic window.
	- Lesions of the superfcial buccal mucosa and tongue lesions on its anterior half and corresponding lateral borders can be evaluated better.

Advantage: Better visualization of lesion details. Limitation: Inaccessibility to tongue lesions along the posterior half and corresponding lateral borders.

### (c) *Fruit Jelly Technique*.

(Figs. 8.49a, b, and 8.50a–d)


#### Advantages:


Limitation: Inability to evaluate lesions involving far posterior aspect of Vestibule.

**Fig. 8.46** Cheek layers by "Puffed Cheek" Technique. (1) Mucosa. (2) Submucosa. (3) Buccinator. (4) Buccal fat. (5) Subcutaneous tissue. (6) Skin

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.47** (**a**, **b**) Cheek layers by "Puffed Cheek" Technique. m-mucosa, sm-submucosa, b-buccinator, bf-buccal fat

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.49** (**a**) Axial panoramic (**b**) Coronal Cheek layers by "Fruit Jelly" Technique. (1) Jelly (2) Angle of mouth (3) Alveolar process (4) Masseter (5) Mandible (6) Parotid (7) Maxilla (8) Mandible (Asterisk)- Upper and lower gingivobuccal sulcus

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.50** (**a, b, c**, and **d**).Cheek layers by "Fruit jelly" Technique. Panoramic axial slices. Coronal slices showing superior and inferior vestibules along with layers of cheek/alveolar surfaces

### **8.11.6 Case Presentation**

#### **HRUSG Cheek: Scope of Use and Limitations**

Scope of practice of HRUSG cheek includes


#### **Limitations**


#### **Clinical Conditions that Can Be Evaluated**


#### **Notifable Lesions**


#### **1. Infammatory / Infective Pathology**

(a) *Cheek cellulitis with evolving abscess (Fig. 8.51a–d).*

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.51** (**a, b, c,** and **d**).Cheek cellulitis with evolving abscess. Diffuse soft-tissue thickening, edema of deep subcutaneous fat plane, edematous buccinators and submucosal plane with mild echogenic tracking collection within the fascial planes

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.53** (**a**–**d**) Chronic osteomyelitis mandible. HRUSG showing hyperechoic lesion with hypoechoic halofungal granuloma

**Fig. 8.52** (**a, b** and **c**). Cheek abscess. Focal organized thick echogenic collection in the deep subcutaneous plane with minimal extension into buccinator muscle (45 year old male, with habit of chewing betel nut)

©Association of Oral and Maxillofacial Surgeons of India


#### **2. Benign Pathology.**


#### **3. Malignant Pathology.**


©Association of Oral and Maxillofacial Surgeons of India


#### **4. Vascular malformations**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.55** (**a, b** and **c**) Oral submucosal fbrosis. Axial slice showing thickening of the submucosal layer in OSMF in comparison to the normal thickness of the submucosal layer

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.56** (**a**) and (**b**). Tiny calculus of about 1.2 mm revealed by HRUSG at Stenson's duct opening. (Pain while chewing food. No swelling)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.57** (**a**) and (**b**). Intraoral Mucocele. Well-defned cystic lesion in the submucosal layer with internal minimal echogenic contents. Possible diagnosis of mucocele given, later confrmed by HPR. (35 year old female, presenting with right-sided cheek swelling and mild pain)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.58** (**a, b, c,** and **d**). Cheek lymphangioma. Fluid-flled cystic lesion deep to submucosal layer with deep space extension adjacent to the masseter medial to mandibular ramus MRI coronal T2W imaging confrms hyperintense fuid along left side of cheek extending into infratemporal fossa (25 year old male, presenting with soft, painless swelling of left cheek)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.59** (**a**) and (**b**). Epidermoid cyst of cheek. Well-defned complex cystic lesion in the subcutaneous plane with internal echogenic contents causing displacement of underlying cheek layers (28 year old male presenting with painless left cheek swelling)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.60** Intramasseteric Lipoma. Elongated intramuscular lesion isoechoic to the subcutaneous fat with internal echogenic strands representing intramasseteric lipoma. (30 year old female, presenting with painless swelling of cheek)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.61** (**a**) and (**b**). Stenson's duct calculus. Hyperechoic calculus in the Stenson's duct with nondilated duct proximal to the calculus (23 year old male, with history of intermittent pain on right side of the cheek)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.63** Buccal mucosal malignancy with intact submucosa and buccinator. Growth predominantly involving the mucosa, distinct from submucosa (between asterisk) buccinator (star) appears normal. (55 year old male with irritating nonhealing ulcer left cheek)

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.64** (**a, b,** and **c**). Early Carcinoma of the cheek better seen on HRUSG than by CT slice at the same level. Proved by Histopathology (52 year old male with squamous cell carcinoma of the buccal mucosa)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.65** Buccal mucosal carcinoma

**Fig. 8.66** (**a**) Buccal mucosal carcinoma (Resting phase). (**b**) Buccal mucosal carcinoma (Fruit jelly technique). Patient was unable to perform the puffed cheek technique. Mass involving the mucosa, submucosa, buccinator, and fat

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.67** (**a, b** and **c**). Superior vestibular malignant mass. Coronal sections revealing predominantly hypoechoic, superior vestibular mass with irregular margins extending into cheek layers and causing underlying bony destruction. Comparison between (**a**) neutral cheek, (**b**) fruit jelly Technique and (**c**) CT

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.68** (**a**) and (**b**). Tongue malignancy against cheek wall. Irregular lesion along the Right anterolateral margin of the tongue by "Tongue touch" technique. Few enlarged lymph nodes are also noted with loss of hilar anatomy representing metastatic lymph nodes. (40 year old male, with complaint of swelling over the tongue)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.69** (**a, b, c,** and **d**) Buccal malignancy with mandibular infltration. Heterogeneous mass lesion along the buccal mucosa extending into lower buccogingival sulcus with infltration into submucosa and buccinator muscle. Focal cortical break is also noted in the mandibular bone with intraosseous infltration. (48 year old male tobacco chewer presenting with right cheek swelling)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 8.70** (**a, b, c,** and **d**) Arteriovenous malformation (AVM) cheek. Focal soft-tissue thickening with internal hypoechoic areas. Doppler study shows multiple vascular channels with high velocity, low resistance fow suggestive of AVM. (40 year old female presenting with history of swelling and intermittent pain)

**Fig. 8.71** Cheek Hemangioma. Mixed echoic hemangioma with phlebolith. Absence of fow signals due to low-velocity fow

©Association of Oral and Maxillofacial Surgeons of India

#### **8.12 Conclusion**

It is extremely diffcult to limit radiology to a chapter and what has been written does not represent the whole of maxillofacial radiology. Only the relevant aspects and the bare minimum essentials of radiology for maxillofacial surgeons have been covered in this chapter. The entire range of radiology for maxillofacial surgeons, dealing with surgical problems pertinent to the maxillofacial region, would require more expansive and elaborate writing.

This chapter on radiology provides an outlook to the surgeon, who can proceed to applying radiology in his everyday surgical practice. In the event of encountering any lacunae in the book, the MFS must refer to the textbooks dedicated to maxillofacial radiology. Being a surgeon, the MFS should be aware of the use of the chest radiograph and its applications in his practice. The role of high-resolution ultrasonography has also been emphasized in this chapter. Dental radiology, both extra and intraoral, has not been included since all maxillofacial surgeons have extensive knowledge of the same in their surgical practice.

Since it is the MFS who is acquainted with the patient's clinical status, he must properly plan the imaging pathway for the patient. It is for this purpose that the MFS should be aware of the various imaging modalities as regards their nature, mode of image formation, their usefulness over other modalities, and their drawbacks. Radiation safety and cost effectiveness of a specifc imaging modality also need to be kept in mind. The imaging method selected should be one that provides the required information within the shortest time possible, be the safest option for the patient, and be the most economical, while at the same time providing maximum information.

The MFS can commence with simple basic imaging methods like plain radiography or USG and later proceed to higher imaging methods in case the basic methods were not enough to satisfy the surgeon's needs for patient management. A recent costlier imaging method does not necessarily mean it is the best. Many times, it is the simpler basic imaging methods that provide more crucial fndings that help in understanding complex disease processes.

**Acknowledgments** The authors would like to acknowledge & thank Dr Niranjan Kumar, M.Ch FRCS. ; Honorable Vice-Chancellor, Shri Dharmasthala Manjunatheshwara University for his valuable constructive suggestions and constant support towards this endeavour.

#### **References**


#### **Further Reading**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

**Part V**

**Principles of Maxillofacial Surgery**

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_9

## **Operating Room Protocols and Infection Control**

Rishi Kumar Bali

#### **9.1 Introduction**

A study comprising data from 56 countries in 2004 stated that the annual major surgery volume was estimated to be 187–281 million operations, accounting for approximately one operation annually for every 25 human beings alive [1]. In subsequent studies, data were obtained from a total of 194 Member States of the World Health Organization for the years 2005–2012. According to these studies, 312.9 million operations took place in 2012, showing an increase from the 2004 estimate of 226.4 million operations. 6.3% and 23.1% of operations were carried out in *very-low* and *low*-expenditure countries representing only 36.8% (2573 million people) and 34.2% (2393 million people) of the global population of 7001 million people, respectively [2]. The incidence of postoperative infections reported among the developed countries like UK and USA was approximately 5% and 5–6%, whereas in developing countries like India it is much higher, accounting for approximately 10–25%. [3, 4].

The main problem encountered in the practice of surgical safety is that existing safety practices are not adequate in some countries. Lack of resources is the main reason behind this, particularly in developing countries. Good infection prevention and control is essential to ensure the safety of the patient undergoing any surgical procedure in the operating theater. The surgical site infections (SSIs) constitute 20% of the total hospital-acquired infections [4]. These infections cause substantial patient mortality and morbidity and burden healthcare systems with massive costs. Since these infections are primarily acquired during the operative procedure when the wound is still open, stringent protocols need to be followed at this point to minimize their onset.

### R. K. Bali (\*)

## **9.2 Terminology**

To establish surgical protocols, it is important to understand the basic concepts of sterilization, asepsis, and infection control. In this respect, the following terminologies are very commonly used:

#### **Antibiotics**

These agents are a by-product of certain microorganisms, which either have the capacity to destroy or inhibit the growth of other microorganisms at low concentrations.

#### **Anti-Infective**

A substance (or drug) capable of killing microorganisms or inhibiting their growth, in particular, pathogenic microorganisms. This is a general term used to encompass those drugs that specifcally act on certain types of microorganisms, including antibacterial (antibiotics), antifungal, antiviral, and antiprotozoal agents.

#### **Antimicrobial Agent**

Any agent synthetically or naturally obtained that can destroy or attenuate the microorganisms.

#### **Antisepsis**

It is the process in which microbial agents on a living surface are either killed or their growth is arrested.

#### **Antiseptic**

These are the substances applied on the living tissues to reduce the possibility of infection, sepsis, and putrefaction by inhibiting the activity or growth of the microorganisms.

#### **Asepsis**

The state of being free from living pathogenic organisms.

#### **Aseptic**

Free of or using methods to keep free from microorganisms.

**9**

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 173

Postgraduate Department of OMFS, DAV Dental college hospital, Yamunanagar, Haryana, India

174

It is defned as the processing and packaging of a sterile product into sterilized containers followed by proper sealing with a sterilized closure in a manner to control microbiological recontamination.

#### **Bactericide**

It is an antimicrobial agent that has the capacity to destroy both nonpathogenic and pathogenic organisms but may not destroy bacteria in spore form.

#### **Bacteriostatic**

It is an antimicrobial agent that inhibits the growth of microorganisms but is not capable of killing them.

#### **Bioburden**

The occurrence of viable microorganisms on a surface or object before the sterilization procedure.

#### **Biologic Indicator (BI)**

A standardized test preparation of bacterial spores used to demonstrate effective sterilizing conditions by providing a defned resistance to a specifc sterilization process.

#### **Chemical Indicator**

These are agents or devices used to monitor or confrm the attainment of one or more of the parameters required for a satisfactory sterilization process or used in a specifc test of the sterilization equipment.

#### **Chemisterilant**

It is an agent, chemical in nature with properties that kills all forms of microbial agents, including spores.

#### **Cleaning**

It is the process of removing all forms of foreign materials (from objects using detergents & water, soaps, and enzymes) by employing the mechanical action of washing or scrubbing the object.

#### **Contamination**

It is the process of entry of microbial agents into tissues or any aseptic environment.

#### **Crossinfection**

The spread of infection from one person, object or place to another.

#### **Decontamination**

The process by which a person or a surface is made free from all the agents that contaminate the surface and lead to the spread of infections. [5]

#### **Detergent**

It is a chemical agent with cleansing actions in dilute solutions, which, on combining with impurities and dirt, make them more soluble.

#### **Disease**

Disruption of the normal performance of the vital functions of a plant or animal by an infection.

#### **Disinfectant**

This is an agent, usually a chemical, applied on inanimate objects that destroys microorganism in the vegetative form but not the spores.

Chemical disinfectant agents are categorized into low level, intermediate, and high level (depending on the product claims and regulatory requirements in different parts of the world).


#### **Disinfection**

Antimicrobial process to remove, destroy, or deactivate microorganisms on surfaces or in liquids. Disinfection is often considered as a reduction of the numbers and types of viable microorganisms (or "bioburden") but may not be assumed to render the surface or liquid free from viable microbial contamination (in contrast to sterilization).

#### **Droplet Nuclei**

These are those particles of 1–10 μm that are implicated in the spread of airborne infections.

#### **Exogenous Infection**

The infecting microorganism comes from an external source.

#### **Fomites**

Any inanimate object that is capable of absorbing or transmitting infectious microorganisms from one person to the other.

#### **Fumigation**

The process of disinfecting or purifying an area or object with the fumes of certain chemical agents.

#### **Germicide**

Agents that are designed to kill and destroy pathogenic organisms on the surface of different things.

#### **Infection**

It is the process of invasion of the tissues by microorganisms and their multiplication in the body of the host to produce disease.

#### **Microorganisms or Microbe**

Microscopic organisms, which may exist in its single-celled form or in a colony of cells.

#### **Minimum Effective Concentration (MEC)**

The lowest concentration of a chemical or product, used in a specifed process that achieves a claimed activity.

#### **Minimum Recommended Concentration (MRC)**

The lowest concentration of a chemical or product specifed by the equipment manufacturer to be used in a process.

#### **Nosocomial**

This comes from two Greek words, i.e., "*nosus"* meaning "*disease*" and "*komeion"* meaning "*to take care of."* Also known as "hospital-acquired infections." These are the infections originating or taking place in a hospital.

#### **Operating Room (OR)**

The operating room or operating theater is a facility within a hospital where surgical procedures are carried out in an aseptic environment.

#### **Pathogen**

A pathogen is a tiny living organism, such as a bacterium or virus that is capable of producing disease in an individual.

#### **Resistance**

It is the natural ability of the agent to oppose the effects of any harmful agents.

#### **Soil**

Natural or artifcial contamination on a device or surface following its use or simulated use.

#### **Sterile Barrier System**

Packaging that prevents the ingress of microorganisms following a sterilization process, thereby preserving the sterile state.

#### **Sterilizer**

Equipment designed to achieve sterilization.

#### **Sterilizing Agent**

Physical or chemical agent (or combination of agents) that has suffcient microbicidal activity to achieve sterility under defned conditions.

**Septic**

Contaminated or infected.

#### **Spores**

These are the reproductive forms of some microorganisms that can survive harsh environmental factors and have the capability of developing into new viable microbes.

#### **Sterilization**

Sterilization is a process that destroys or removes all microbial life completely, including spores by means of certain chemical or physical processes.

#### **Sterile**

Free from living microorganisms.

#### **Sterilize**

Total destruction of all living forms.

#### **Vector**

It is an organism that does not cause disease itself but which spreads infection by conveying pathogens from one host to another.

#### **Virulence**

It is a pathogen's ability to infect, sustain, or spread infection in a living a host. Historical background of present day protocols is enumerated in Table 9.1.

#### **9.3 Surgical Site Infections**

Approximately 2–5% of all surgical patients tend to acquire surgical site infections (SSIs) [4]. In developed & highincome countries (HICs), SSIs are the second most common cause of healthcare-associated infections [6], whereas in Low- & Middle-Income Countries (LMICs) or underdeveloped & developing countries these infections are the most common ones. Thus, to reduce the risk of surgical site infections, a more systematic approach has to be adopted, based on proper knowledge regarding the status of the patient, type, & time of the operation, personnel involved and the health care facilities available during a surgical procedure. The main pathogenic source of surgical site infections is the endogenous fora (usually aerobic gram positive cocci) of the patient present in the skin, the mucous membranes, or the hollow viscera. The exogenous sources of infection include


**Table 9.1** Historical background leading to proper sterilization and disinfection protocols

members of the surgical team, environment of the operating theater and tools, materials & instruments brought to the sterile zones during the surgical procedure. Various strategies employed to prevent or control the occurrence of surgical site infections include reducing the contamination by microorganisms on the sterile surgical instruments as well as the body of the patient, prophylactic preoperative antibiotic coverage, carrying out the surgical procedure carefully, proper handling of the operating room.

#### **9.4 Surgical Safety**

Surgical safety is of utmost importance in order to prevent major and life-threatening complications leading to undue loss of life and patient morbidity. Thus, a list of ten essential objectives with a surgical safety checklist have been elucidated by the WHO to be followed by all the personnel present in the operating room to reduce the risk of such complications [7] (Tables 9.2 and 9.3).

#### **9.5 Environmental Control and Design**

#### **Operating Room (OR)**

The operating room or operating theater is a facility within a hospital where surgical procedures are carried out in an aseptic environment. Since the operating theater is a highly sterile, aseptic, and restricted area in a hospital setting, it is **Table 9.2** WHO: Ten essential objectives for safe surgery


mandatory for all the personnel concerned to have a proper understanding of the working of the operation theater abiding by certain laws, regulations, and professional guidelines. Integrated infection control in the operation theater is the key to decreasing morbidity and mortality among the patients undergoing surgery.

Following essentials must be present in an operating room:


#### **Table 9.3** WHO's Surgical Safety Checklist


1.2 to 1.5 m. Sliding doors are preferred than spring-loaded doors in order to minimize the generation of the air currents during the opening and closing of the doors. Windows made from glass are preferred, which are to be planned on one side only.


#### **Different Zones of Operation Theater Complex**

There are four different zones observed in any operating room complex described on the basis of type of cleanliness present, presence or absence of microorganisms, and the different procedures to be carried out in each zone (Fig. 9.1).

	- Changing room for all the concerned persons
	- Transferring passage for the materials, equipment, and the patient
	- Rooms for administrative staff
	- Storage & record maintenance
	- Pre- and postoperative
	- Intensive and Coronary Care Units
	- Storage rooms to keep the sterilized objects
	- Clean rooms
	- Storage room for equipment
	- Rooms designed for surveillance, maintenance, and frefghting
	- Exit areas in case of emergencies exists

#### **Fig. 9.1** Different zones of operation theater complex

©Association of Oral and Maxillofacial Surgeons of India


#### **Important Points**


#### **Maintenance in the Operation Theater**

– The machinery must be surveyed at least every week.


#### **9.6 Disinfection and Sterilization**

Sterilization is the ultimate procedure in controlling the undesired activities of microorganisms that are outside of the human body. Its purpose in the operating feld is to prevent the spread of infectious disease, and in surgery, it primarily relates to processing reusable instruments. Surgical instruments are an integral part of surgical feld and, being reusable, have greater chances of spreading the microorganisms if any of the reprocessing steps fails. Steps of reprocessing include cleaning, repackaging, disinfection or sterilization, and reusing. Cleaning, being the frst step in the cycle of reprocessing,

**Table 9.4** Spaulding Classifcation of Medical Devices And Level of Disinfection


is the major step in the removal of any organic matter present on the surface of the instruments. Any failure in the removal of the visible soil at the initial stage can create a discrepancy in the effcacy of the subsequent disinfection and sterilization procedures. Sterilization is more effective a process than disinfection. The process of disinfection is carried out with the use of various chemical agents. Chemical disinfecting agent necessarily does not kill all microorganisms or spores present on an inanimate object but instead reduces the number of microorganisms to a level that is not harmful to health. Depending on their potency against microbes, they are classifed as *High-*, *Intermediate-,* or *Low-level* disinfectants.

The type of the sterilization procedures to be carried out for an object depends upon the classifcation of the instruments based according to the Spaulding Classifcation of the medical devices, the type of material of which the object is made of, the microorganisms to be present on the object, and availability of the sterilization methods and equipment (Table 9.4).

**The Instrument Processing (Decontamination Steps)**  (Fig. 9.2)

**Fig. 9.2** Instrument processing steps

©Association of Oral and Maxillofacial Surgeons of India

Various methods of decontamination include.


Processing of the clinical or surgical items is a two step procedure.

	- Cleaning is the process of removing all the foreign particles present on the surface of the object, which is accomplished by means of two main steps, i.e., cleaning by friction to remove foreign particles and rinsing away by fuids to remove the debris so cleaned.
	- If the objects to be sterilized, remain soiled with foreign materials, the microorganisms will be trapped in the organic matter and may interfere with the proper sterilization or disinfection procedure. Therefore, thorough cleaning should always precede the sterilization process.
	- Cleaning may be manual or mechanical and is normally accomplished by the use of water, detergents, and mechanical agents. Detergent is essential to dissolve proteins and oil that can reside on instruments and equipment after use.

With the advancement in the sterilization equipment, most units are automated and there is very less handling of dirty equipment by the concerned staff. The equipment to be processed is placed in trays and is ready for washing.


It is an active method that is carried out by thoroughly brushing the item with the help of a toothbrush under water to prevent the release of aerosols. The brush should be thoroughly cleaned after use and should be dried. The cleaned items are then dried and made ready for the proper sterilization procedure to be carried out depending upon the material of which they are made and the use they perform.

Manual cleaning is necessary when:


There are times when cleaning alone cannot remove the debris present on the surface of the objects as the items become highly soiled with foreign materials. For this, it is sometimes necessary to soak instruments/objects prior to cleaning. A container having a deeper base is flled with detergent & water and all the instruments are kept in it for 3–5 min. The solution prepared is agitated by shaking it vigorously. The cleaned instruments are now removed from the container and placed over a tray for air drying.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 9.3** Manual Cleaning

#### B. **Disinfection and Sterlization**

	- (a) Most commonly used for heat-labile instruments/ objects (e.g., endoscopes) where single use is not cost effective.
	- (b) Disinfectants used for this purpose are
		- Glutaraldehyde: 2% for 20 min.
		- Hydrogen peroxide: 6%–7.5% for 20–30 min.
		- Per acetic acid: 0.2–0.35% for 5 min.
		- Ortho-phthalaldehyde (OPA) for 5–12 min.
	- (c) Steps:
		- All items to be disinfected are cleaned and dried.
		- Fresh disinfectant solution should be made each day in a sterile container. If a previously prepared solution is to be used, an indicator strip is dipped in the solution to check for the effectiveness of the solution.
		- Open all hinged instruments and disassemble whichever possible.
		- Place all items in the solution completely submerged in the container.
		- The container is covered and the instruments are allowed to soak in for 20 min.
		- Remove the items using dry, high-level disinfected pickups.
		- Rinse thoroughly with boiled water.
		- Air-dry by placing on disinfected tray.
		- Items disinfected are covered in a disinfected container and used within a week.

#### *Sterilization*

Sterilization is a method by which an article, medium, or surface is made free from all microbial invasions, including spores. The main aim of sterilization of instruments is proper delivery of sterilized instruments at the operating feld, thereby maintaining a sterile environment and reducing the spread of infections from one person to another. Proper handling of the sterilized instruments is done by appropriate wrapping and storage of the instruments, thereby increasing the shelf life of the sterilized instruments. The instruments should be bagged or wrapped in a muslin cloth or clear pouches or paper before and after the procedure and the wrapping should be sealed with tape. No pin, staple, or any paper clips are to be applied on the wrapping as these may create small openings, which may allow entry of microorganisms, thereby hampering the process of sterilization. Sterilization is accomplished by:

	- This is the most simple and effcient means of sterilizing instruments. It is also commonly called steam sterilizing or autoclaving.
	- The steam autoclaves best suited for outpatient practice are usually made to operate in the following range.
		- Temperature 121 °C (250 °F) at a pressure of 15 pounds per square inch (psi) for 15 min.
		- Temperature 134 °C (270 °F) at a pressure of 30 psi for 3 min. This process termed "fash sterilization" has practical use in the operating room where fast sterilization of instruments may be necessary.
	- This combination of moisture and heat provides the bacteria-destroying power currently most effective against all forms of microorganisms.
	- Mainly used for items that are wrapped or porous.
	- Autoclaves are either classifed as horizontal or vertical (based on design) and gravity displacement or vacuum type (based on functioning).
	- Autoclaves can also be classifed as Type "N" and Type "B."
	- Type "N" autoclaves are the ones that do not remove air from the sterilization chamber with the help of a vacuum pump. These are used for solid loads.
	- Type "B" autoclaves remove air from the sterilization chamber with the help of a vacuum pump. Wrapped and hollow instruments, which can be sterilized and used later, are to be sterilized by this type of autoclave.
	- Importance of bagging the instruments for sterilization.
		- The main aim of bagging or wrapping the instruments prior to sterilization procedure decreases the chances of contamination of the items after the sterilization procedure is complete.
		- Two-layer wrapping of objects should be preferred and the materials used for this can be cotton fabric or muslin, paper, newspaper (Fig. 9.4).
	- Monitoring of sterilization.
	- Sterilization monitoring is a process by which adequate sterile environment and the effectiveness of the procedure is determined by assessing the biological, mechanical, and chemical parameters.
	- The most widely used and accepted parameter of assessing the sterilization procedures is the use of biological indicators (BIs) that directly inhibit the growth of highly resistant microorganisms, rather than merely testing the physical and chemical conditions necessary for sterilization. Since the spores present in a biological indicator are in a much higher number and are highly resistant by nature compared to the other and common microorgan-

**Fig. 9.4** Diagram depicting the way the instruments are wrapped for sterilization

©Association of Oral and Maxillofacial Surgeons of India

isms found on items used for the patient, an inactivated biological indicator indicates that the other microorganisms are killed depicting an effective sterilization procedure. A control BI, from the same lot as the test indicator and not processed through the sterilizer, should be incubated with the test BI; the control BI should yield positive results for bacterial growth.


being exposed to the sterilizing conditions. These chemical agents are called the chemical indicators and these include TST (Time-Steam-Temperature) Strip. This TST strip is to be placed in a big surgical wire basket and when exposed to a critical time, steam, and temperature it undergoes a change in color from yellow to dark blue indicating complete sterilization procedure. Another strip is to be used when double-layered packing of instruments in crepe paper is done to assess the parameters inside the sterilizer.

	- There must be a separate area for storing of the sterile instruments and single-use (disposable) products.
	- The storing of the bagged sterilizer objects can be depicted either by the date on which they are sterilized or the procedure for which it is to be used or an event causing it to become contaminated.
	- All the packed items must be carefully inspected before using to verify the integrity of the outer covering and the condition of the packing (dry/wet).
	- Once the packing is assessed and if any breach is seen in the packing, the wrapping should be replaced and the instruments again sent for the sterilization procedure.
	- All the sterilized instruments must be kept in covered drawers.
	- It is used for sterilization of heat-labile and moisture-sensitive items, supplies, and equipment.
	- The operating cycle ranges from 2–24 h and it is a relatively expensive process.
	- It can be used for glass, paper surfaces, clothing, plastics and metals, food stuffs, and dental equipment.
	- It is unsuitable for fumigating rooms because of its explosive property.
	- It may be used for sterilization of instruments with cutting surfaces.
	- No corrosion occurs with this method of sterilization.
	- Dry heat sterilization, which usually occurs consists of hot air oven has typical cycles of 1 h at 171 °C or 2 h at 160 °C.
	- Air is a poor conductor of heat and requires a long time for getting the instruments effectively sterilized.
	- This is also a choice for some limited circumstances.
	- Some instruments cannot be subjected to high temperatures and in a feld environment chemical sterilization may have to be used.
	- The disinfectant must remain in contact with the surface for appropriate time.
	- Disinfectants include Chlorine solutions, 2–3.2% glutaraldehyde, iodophors, and phenols.

#### **9.7 Operating Room Decorum**

#### 1. *Hand hygiene:*

Hand hygiene by operation theater persons is the most effcient way to reduce the risk of spread of infections.

	- Surgical hand wash or surgical hand rub should be carried out prior to the procedure in order to decrease the residing fora of the hand.
	- Steps:
		- All jewellery from wrists and hands must be removed.
		- The temperature of water is to be adjusted so that it is slightly warm. Hands and forearms are to be washed 5 cm above the level of the elbows to remove any particles of dirt.
		- Before performing the frst scrub of the day, a nail cleaner is used to clean the fngernails and the nail beds.
		- The nails should be cut short and no nail polish should be used.
		- Antimicrobial agent is to be applied on the hands and in circular motion; lathering should begin at the fnger tips of one hand and between the fngers, continuing from the fngertip to 5 cm above the elbow. The same process is to be repeated for other arm and hand.
		- The rubbing should be done for a period of 3–5 min.
		- Each arm is to be washed separtely at the level of elbow, starting at the fngertips.
		- One side of the sterile towel is used to dry the fngertips up to the elbow of one hand and the other side is used to dry the same on the other hand.

3. *Barrier techniques:*

Barrier techniques are useful where the chances of spread of infection are higher.

(a) Head Cover

Prior or during the procedure, all facial and head hair should be tied properly and covered by means of head covers. Ideally head covers should be disposable and made of soft, nonporous cloth like material. If one has long hair, the hair should be tied in a bun. In situations where tying a bun is not possible, use of helmets or hoods or headgears is of utmost signifcance.

	- Tuberculosis is one of the most common infectious diseases that can spread through airborne route,
	- The main aim of using a mask is the prevention of transmission of infectious agents from the member of the operating team to the patient's wounds and also protecting the operating team members from the splashes and sprays from the patient.
	- The masks, which are disposable in nature, are always preferred.
	- The mask should be made of synthetic fbers, must be fat with two or three pleats that expand to cover the area up to chin, and should have flters of polypropylene or polyester (Fig. 9.5).

These are the pair of garments to be worn over, or instead of regular clothing of the persons involved in the surgical procedures to protect the transmission of any infectious agent present on the regular clothing from the operating personnel to the patient or any other personnel. These should have a simple design, should be comfortable, should be easy to clean and wash, should be economical, easily replicable if damaged and should have minimal place for the contaminants to hide.

(d) Surgical gowns

These are a loose pair of clothing to be worn over the scrub suits or cover gowns at the time of the surgery to protect both the patient and the operating personnel from transfer of microorganisms, blood or body fuids, and another particulate matter.

Steps of wearing gown:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 9.5** Surgical Mask

(e) Gloves

They help to protect the operator from infection by bacteria and viruses from patient's blood. Gloving is essential to protect both the surgeon and the patient from blood-borne viruses and to prevent wound from becoming contaminated with the surgeon's skin fora. The "open gloving" and "closed gloving" technique of donning the gloves should be employed for wearing gloves.

	- Handwashing must be performed under aseptic conditions.
	- Inspect the outer covering for the integrity. Open the frst nonsterile packaging by peeling it completely off the heat seal exposing the inner sterile wrapper, but without touching it.
	- The inner sterile packing is kept on a dry area, without touching the outer surface. Open the package and fold it toward the bottom so as to unfold the paper and keep it open.
	- By using index fnger and thumb of one hand, the folded edge of the glove is grasped.
	- In a single movement the other hand is slipped into the glove.
	- The second glove is picked by using the cuff of the other glove and sliding the fngers of the gloved hand into it.

©Association of Oral and Maxillofacial Surgeons of India

	- If the cuffs are not ftting, a tuck is taken in each gown.
	- The circulating person should open the outer covering of the glove and should fip them onto the sterile feld.
	- The inner packing containing the gloves is opened carefully and the glove is picked up by the folded cuff edge with the hand covered by the sleeve.
	- The glove is placed on the sleeve of the opposite gown, the palm facing downwards, with the fngers of the glove pointing toward the shoulder.
	- The gloves should be placed in such a manner that the rolled cuff edge of the gloves connects

the sleeve to the gown cuff. Bottom cuffed and rolled edge of the glove is grasped at the bottom with the index fnger and thumb.


Drapes are used during surgical procedure to protect the contacting of the unprepared surfaces/areas and maintaining the sterility of environmental, equipment, and the surrounding of the patients.

The different drapes available are:-

• Towel drapes, which are used for squaring off the operative site, wrapping syringes & small instruments, and

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 9.8** Putting on sterile gloves by closed gloving technique

drying of the hands. These must be more resistant to water and must be made of cotton compared to linen.


#### **9.8 Classifcation of Surgical Wounds**

A widely used classifcation of surgical wounds is based on an estimate of likelihood of bacterial contamination of the operative site. In 1964 [9], National Academy of Sciences/ National Research Council defned fve general classes of operations:

1. *Refned-Clean:* Elective operations not drained and primarily closed.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 9.9** Different types of drapes


Currently, this classifcation has been condensed into four groups for general use, without a subdivision of the clean category and in the modifed form it is categorized into four categories [10]

	- Elective (not urgent or emergency).
	- Primary closed.
	- No acute infammation or transection of tracheobronchial, biliary, gastrointestinal, oropharyngeal tracts.
	- No technique breaks.
	- Emergency or urgent cases that are otherwise "clean."
	- Elective procedures.
	- Reoperation via "clean incision" within 7 days.
	- Blunt trauma, intact skin, and negative exploration.
	- Acute nonpurulent infammation.
	- Major technique break or major spill from hollow organs.
	- Entrance of genitourinary or biliary tracts in presence of infected urine or bile, respectively.
	- Penetrating trauma less than 4 h old.
	- Purulence or abscess.
	- Preoperative perforation of tracheobronchial, biliary, gastrointestinal, oropharyngeal tracts.
	- Penetrating trauma more than 4 h old.

### **9.9 Risk Factors Afecting the Rate of Postoperative Wound Infections**

*"Cut Well, Sew Well, Heal Well"* is an axiom favored by surgeons but is not always destined to be true. Altemeir and Culbertson (1965) [11] depicted that the risk of infection varies:


These factors interact in a complex way to fasten the development of infection. Since the days of Altemeier, clinical and epidemiologic studies have identifed the risk factors that affect the rate of postoperative surgical site infection. This can be best explained by the classical epidemiological triangular model, i.e., model of interaction between agent host and environment resulting in disease (Fig. 9.10).

The risk of postoperative wound infection also depends on the patient factors, pre and intraoperative factors (Table 9.5). Haley et al. (1985), in the Study of the Effcacy of Nosocomial Infection Control "(SENIC)," [13] identifed four independent and additive risk factors for postoperative wound infection. These factors are operation on the abdomen, operation lasting for more than 2 h, contaminated or dirty wounds (NRC CLASSIFICATION), and the presence of more than three discharge diagnoses.

• Hair removal should not be performed on routine basis to decrease the risk of surgical site infection. Razors should not be used to remove the hair as they increase the chances

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 9.10** Classical Epidemiological triangle



of infections [14]. Electric clippers with disposable heads must be used only for removing hair few hours prior to the surgical procedure.


#### **9.9.1 Factors Infuencing the Development of Nosocomial Infections**

#### **9.9.1.1 The Microbial Agent**

Hospital infections occur as a result of a variety of microorganisms. The microorganisms causing the disease may be divided into the following categories:


During the stay in a hospital, the patient comes in contact with various kinds of microbial agents (such as viruses, fungi, parasites, and bacteria), which are the main cause of the occurrence of infections in a patient. This exposure is not the only reason for the development of hospital-acquired infections. The other possible reasons are the host's natural defense mechanisms (healthy/compromised/immunosuppressed), conditions present in a hospital environment, microbiology of the microbial agents (characteristic features), infective material present on the microbial agent, resistance to the antimicrobial agents, and other factors. The hospital-based infections may be a result of the spread of infection from one person to the other or by the residential fora of the patient or from any contaminated sources or from sources of the external origin (e.g., airborne diseases).

Following are the factors that are the main sources of spread of hospital-based infections:

#### **9.9.1.2 Susceptibility of the Patient**

Patient factors that lead to the occurrence of infection are age, host's immune response, presence of any disease, and interventions, which either help in diagnosing or treating any condition. Patients, either infant or older individuals, are at a higher risk of acquiring infections. Patients having a compromised immune system, undernourished, having some underlying chronic disease (AIDS, leukemia, malignant tumors, renal failure, diabetes mellitus, etc.), undergoing irradiation therapy, all at the highest risk of being infected by the hospital-based infections. Certain processes like catheterization, biopsy, intubations, etc. make the patient more vulnerable to these infections.

#### **9.9.1.3 Resistance of the Bacteria**

Resistance of bacteria to antimicrobial agents is seen with the prolonged or prophylactic use of these agents. The microbial agents present normally in the human fora have both sensitive and resistant strains. Some antimicrobial agents have their action on sensitive strains by suppressing their activity, whereas the resistant strains are still active. These active resistant strains are the major cause of the development of resistance against the antimicrobial agents. Examples of resistant microbial agents are Multiresistant Klebsiella, strains of pneumococci, staphylococci, etc. In low-income or middle-income countries, this is the major problem faced due to unavailability and unaffordability of the better drugs.

#### **9.9.1.4 Month of Operation**

The possible explanation for increased infection rates in summer is the relatively high environmental temperature leading to humid climate, resulting in excessive sweating. In addition, excessive sweating results in the displacement of bacteria lodged in skin appendages to the surface.

#### **9.9.1.5 Use of Electric Cautery**

The use of electric cautery for cutting and coagulation during surgery causes more infammation; more necrosis and abscess than the conventional use of scalpel and thus it increases the susceptibility of tissue for infection. Soballe et al [15], in their experimental study, found that electric cautery lowers the contamination threshold for infection of laparotomies and concluded that electric coagulation current should be used only when the need for meticulous hemostasis outweighs the considerably increases risk of infection.

#### **Fig. 9.11** Sources of hospital-acquired infections

©Association of Oral and Maxillofacial Surgeons of India

#### **9.9.1.6 Duration of Operation**

There is a direct correlation between the infection rate and time taken for the procedure. This may be the result of the more complicated operations being of longer duration, increased wound contamination from airborne bacteria, increased damage to the tissues due to large exposure of the wound, and increased manipulation; moreover, local resistance of tissue is reduced due to drying.

#### **9.9.1.7 Spread of Infection**

The microbial agents are spread by different ways in a health care setup. The different ways with which the agents can spread are contacting, droplets, airborne route, via vehicle, and vector-borne (Fig. 9.11).

Sources of the infectious agents are either external, i.e., from one person to the other, or from the hospital's environment; or internal, i.e., within the patient himself.

• *Contacting* is the most frequent and important route of spread of infections. It is further of two types, i.e.


these particles. The main diseases to be spread via the airborne route are Tuberculosis, Infuenza, Common cold, etc.

• *Vehicle spread* is the spread of infectious microbial agents to the individuals by means of contaminated items such as food, water, medications, devices, and equipment.

*Vector*-borne transmission occurs when vectors such as mosquitoes, fies, rats, and other vermin transmit microorganisms.

#### **9.10 COVID 19 and Maxillofacial Surgery**

The occupational risk of acquiring viral diseases has been well known in Maxillofacial Surgery [16]. The WHO announced the Corona virus pandemic also known as COVID-19 as a public health emergency of international concern on January 30, 2020.

Coronaviruses are RNA viruses infecting many species of animals including humans, name coronavirus was derived from corona meaning crown like because of the morphology observed for these viruses in the electron microscope. This family of viruses includes Middle East Respiratory Syndrome (MERS-CoV), Severe Acute Respiratory Syndrome (SARS-CoV), and novel Coronavirus (n CoV).

Coronavirus is enveloped having round, spherical, or sometimes pleomorphic structure, with size ranging from 80 to 120 nm in diameter, containing a positive-strand RNA. The virus is made up of lipid bilayer envelop, membrane protein, and nucleocapsid, these structures also protect the virus when the virus is outside the host cell. The lipid bilayer forms the viral envelop which anchors the membrane protein, envelop protein, and the spike protein. The spike protein (S-protein) is responsible for the crown-like structure of the coronavirus as it forms the protrusions from the surface which bind to the host cells.

#### **9.10.1 Mode of Transmission of SARs-CoV 2**

Human to human transmission is due to respiratory droplet transmission and contact transmission. Spread occurs through coughing, sneezing, spitting, contacting the body fuids of the infected patient. The COVID-19 can remain infectious on inanimate surfaces from 2 h to 9 days, depending on the humidity, temperature, surface type, and viral load [17]. It has become an occupational threat to health care providers worldwide.

Some of the known routes of spread of infection to health care providers are:


Aerosols generating procedures (AGP) create widespread environmental contamination and therefore pose a greater risk of transmission of infection to healthcare workers. Oral and maxillofacial surgeons are particularly vulnerable to this transmissible disease by way of the droplet or aerosol transmission due to the area of work and the type of instrumentation [18].

The incubation period is long and unpredictable ranging from 0 to 27 days with a mean of 6.4 days. Recent studies have shown that asymptomatic patients and those within the incubation period are also potential spreaders of the disease [19].

#### **9.10.2 Symptoms**

Symptoms may range from mild symptoms to severe respiratory distress and some patients may be asymptomatic.


#### **9.10.3 Radiographic Findings**


#### **9.10.4 Testing and Laboratory Findings**

The real time polymerase chain reaction (RT-PCR) of respiratory secretions from bronchoalveolar lavage, endotracheal aspirate, and nasopharyngeal or oropharyngeal swab is the defnitive test.

Other laboratory fndings include lymphopenia, increased prothrombin time, and mildly raised CRP and ESR.

#### **9.10.5 General Preventive Measures**

COVID 19 has shifted the focus on teleconsulting which includes tele screening, telemedicine, and triage. Telemedicine should be practiced whenever possible to decrease the footfall.

Thorough history should be obtained from the patient regarding COVID 19 illness and elective procedures should be postponed and only emergent conditions should be taken up for surgery.

Patient should be called on the basis of appointments, time between two appointments should be suffcient enough to perform all necessary sanitization measures and ensure minimal patient to patient overlap. In the waiting area, posters should be displayed to encourage hand hygiene and the wearing of masks and the area should be well ventilated. A minimum of 2 m distance should be maintained between the individuals.

Extraoral radiographs should be preferred as an alternative to intraoral periapical radiographs.

In the operatory there should be minimum personnel present, Air Conditioners should be avoided, doors and windows are advised to be kept open. The operating room should be spacious with adjoining two rooms for donning and doffng of the PPE's. No touch sensor-based sanitizer dispenser should be installed at the entry and exit of OR [20].

All the surfaces of equipment like OR table, motor drills etc., should be covered with plastic sheets and sheets to be changed after every patient.

OT's should be equipped with HEPA flter (0.1 micron effciency) and high frequency of air changes (ideally 25 per hour) should be ensured to reduce the viral load [20].

High-volume suctions should be used with one-third of suction jars preflled with povidone-iodine solution.

The Povidone Iodine solution has been shown to have signifcant viricidal activity up to 3 h and it has been advised to coat the oral cavity and nasal passages of both the patient and the operating team before the surgery [21, 22].

Fogger machines with 0.5% sodium hypochlorite can be used for sterilization of dental chairs, tables, doors, doorknob, etc. [20]. One-minute contact of the chemical ensures viral kill.

#### **9.10.6 Personal Protective Equipment**

• Masks including three-ply surgical masks, N95, N99 (FFP3), and the Powered air-purifying respirators (PAPR's) provide viral fltration in the increasing order. It is important to mention that N95 masks were not found to be adequate to prevent transmission in Chinese surgeons and PAPR's had to be used to prevent transmission from COVID patients [23].


#### **9.10.7 Specifc Precautions to Be Taken During Surgery**


As the COVID-19 situation is a dynamic evolving one and there is no defnitive treatment available proper planning and implementation of infection control protocols are key to preventing transmission of the disease in the Maxillofacial settings.

#### **9.11 Control of Nosocomial Infections**

CDC elucidated certain guidelines to check the nosocomial infections in the Study on effcacy of nosocomial infection control (SENIC). These guidelines have decreased the emergence of hospital-acquired infections by a greater number. However, any breach in the infection control procedures can lead to spread of such infections.

Certain conditions leading to improper infection control and spread of such infections are:


#### **9.11.1 Prevention from Nosocomial Infections**

Following are the steps that can be taken by the staff in a hospital setup to prevent the spread of such infections:


#### **9.12 Conclusion**

Preventing and controlling infections is the key factor in improving care and ensuring safety of both the patient and the health care worker. Infection control addresses factors related to the spread of infections within the operation theater complex (whether patient-to-patient, from patients to staff and from staff to patient, or among staff), including prevention (via hand hygiene/hand washing, cleaning/disinfection/sterilization, vaccination, monitoring).

Integrated infection control in the operation theater has various aspects, ranging from its designing ,environmental cleaning , management of biomedical waste and adherence to theatre attire. Use of Personal Protective Equipment (PPE) including gloves, gowns, face masks ,respirators and full face visors are essential to minimize risks of occupational infections. Whether in developed or developing country, where resources are limited, thorough knowledge about the principles of infection control and a little ingenuity will suffce to solve the problem of hospital-acquired infections.

Surgical site infections are a result of microbial invasion in a sterile atmosphere. The main sources of microbial invasion in the operating theater include the atmosphere of the operating theater, the medical and the paramedical staff present at the time of the procedure, surgical instruments, and the patient at times also. Proper designing of operation theater, appropriate microbiological monitoring, proper sterilization, and strict adherence to barrier techniques form the basis to prevent infections in an operating environment.

#### **References**


dine gluconate, 4%, in surgical patients. JAMA Surg. 2015 Nov 1;150(11):1027–33.


#### **Additional Reading**

Surgical site infections: prevention and treatment. https://www.nice.org.uk/guidance/cg74

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## **Pharmacotherapy in Oral and Maxillofacial Surgery**

Latha P. Rao

The human fascination—and sometimes infatuation—with chemicals that alter biological function is ancient and results from long experience with, and dependence on, plants. Many plants produce harmful compounds for defense that animals have learned to avoid and humans to exploit [1]

#### **10.1 Introduction**

With phenomenal increase in the knowledge about mechanism of action of chemical compounds and rapid introduction of new drugs, pharmacology—the science of drugs—has become increasingly important to all health professionals. Practice of maxillofacial surgery utilizes drugs either as primary treatment modality or as a facilitator of surgical procedures. A detailed description of the pharmacodynamics & pharmacokinetics of these drugs is beyond the scope of this chapter. The readers are encouraged to refer to the standard textbooks of pharmacology for the same.

#### **10.2 Antimicrobial Agents**

Infections caused by microorganisms have threatened human life since time immemorial. Some of the organisms had the potential to spread from one infected person to another at an alarming rate causing worldwide pandemics and epidemics. With the discovery of the frst antibiotic, "the magic bullet"—Penicillin, patients could effectively be cured of many life- threatening infections [2].

Antimicrobial agents are of the few classes of drugs that effectively treat the etiology of conditions and not simply alleviate the symptoms of the diseases.

#### **10.2.1 Defnition**

The term antibiotic was frst used by Selman Waksman et al. to describe any substance produced by a microorganism that is antagonistic to the growth of other microorganisms in high dilution [3]. This defnition excluded substances like gastric juices and hydrogen peroxide that kill bacteria but are not produced by microorganisms. It also excluded synthetic antibacterial compounds like the sulfonamides. In current usage, however, the term "antibiotic" is applied to any medication that kills bacteria or inhibits their growth, regardless of whether that medication is produced by a microorganism or not.

#### **10.2.2 Classifcation**

The antibiotics have been classifed in many ways, based on their chemical nature, mechanism of action, type of organisms against which primarily active spectrum of activity, etc. (Table 10.1). The antibiotics exert their remarkably specifc action on the microorganisms, sparing the host, due to their selectivity for target components, which are either absent or not very important in humans. Among these targets are bacterial and fungal cell wall synthesizing enzymes, the bacterial ribosome, the enzymes required for nucleotide synthesis and DNA replication, etc.

#### **10.2.3 Oral Microfora**

The infectious diseases associated with the oral and maxillofacial region have unique microbiological features because of the abundance and variety of microorganisms in this region. The normal fora of the oral cavity consists of up to 1011 bacteria per gram of tissue, with anaerobic bacteria predominating [4]. Although the subtypes and proportions of organisms differ, the general pattern of the indigenous

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_10

**10**

L. P. Rao (\*)

Department of craniomaxillofacial surgery, Aster Medcity, Kochi, Kerala, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 195

L. P. Rao



microfora is similar in healthy individuals. However, systemic diseases and concurrent use of medications result in the presence of unusual organisms as part of the normal fora and an increase in diseases caused by normal organisms that usually are considered to have low pathogenicity. Usually, the microorganisms are held in check by the body's defense mechanisms. When these mechanisms are impaired, infection may result from an otherwise minor bacterial exposure.

The pathobiology of mixed odontogenic infection is relatively clear. The early cellulitis is the result of streptococci, the moderate-to-severe infection is caused by a combination of aerobic and anaerobic bacteria, and the well- circumscribed chronic abscess is caused primarily by anaerobic bacilli alone [5]. A complex mix of strict anaerobes and facultative anaerobes account for most of the odontogenic infections. Empirical antibiotic choices can be made in this situation where the microbiological pattern is well established (Table 10.2).

#### **10.2.4 Guidelines to the Therapeutic Use of Antibiotics**

Understanding that infections are ultimately dealt by the host's immune systems, and antibiotics play only an adjunctive role, is critical. Antibiotic therapy should be reserved for those with clearly established infection. Surgical treatment of the infection also should be initiated as early as possible.

Antibiotics help in preventing infections after a contamination has happened or they can abort a developing infection, if administered early. Antibiotics should not be used as a substitute for the needed surgical treatment.

In most clinical situations, it is easy to determine whether a patient has an infection—local and systemic fndings would point to the diagnosis. Diagnostic diffculty arises when a patient who has had a maxillofacial procedure performed, during the second or third day after surgery, develops swelling and pain. Similarly, elevated temperature and white blood cell count also may be found. Surgical insult and


**Table 10.2** Effcacy of commonly used antibiotics against head and neck pathogens and dosage

prolonged general anesthesia often result in these symptoms. Clinical judgment is important in making the diagnosis, and the clinician should weigh all information available before making the diagnosis of infection.

There are a few basic guidelines to be followed in the administration of antibiotics (Table 10.3).

#### **10.2.5 Consistency in Route of Administration**

In severe infection, parenteral antibiotics are needed to get adequate blood levels. But with an initial response within couple of days, one is always tempted to switch to oral administration. When this is done, the infection may recur because blood levels achieved with oral dose are suboptimal. Maintenance of peak blood levels of antibiotic, until eradication of bacteria, is important, which may take 5–6 days. After the ffth day of parenteral administration, the blood levels achievable with oral administration are usually suffcient.

#### **10.2.6 Cross-allerginicity between Penicillins & Cephalosporins**

A frequently asked question about penicillin allergic patients is whether the cephalosporins can be used safely. Overall the frequency of crossallergenicity between the two groups of drugs is low (7–18%) [10, 11]. Cross-allergenicity appears to be most common among penicillin, aminopenicillins, and early-generation cephalosporins, which share similar R-1 side chains; this is thought to increase the risk of cross-reactivity. Patients with a history of anaphylaxis to penicillins should not receive frst- or second-generation cephalosporins, while third- and fourth-generation cephalosporins should be administered with caution, preferably in a monitored setting.

#### **10.2.7 Patient Monitoring**

The patient should be monitored for the response to treatment and any deterrent should be identifed and rectifed. A second empirical choice should be avoided, if at all possible because the likelihood of success is substantially less. Repeat cultures may also be attempted.

In some cases, the patient may respond well to the empirical antibiotics, but the culture and sensitivity report would reveal that the organisms isolated are resistant to the antibiotics being used. The combined surgical and antibiotic treatment, along with natural host defenses, would have resulted in resolution of infection. The antibiotic may or may not have played an important role. The antibiotic that was clinically effective for the patient should be continued despite the contradictory data.

### **10.3 General Considerations in the Prophylactic Use of Antibiotics**

The original guidelines for timing and use of antibiotics to prevent infection postoperatively were established by Burke and Miles et al.'s experimental observations [12, 13]. They

#### **Table 10.3** Guidelines for the use of antibiotics

#### 1. *Empirical therapy*


noted that antibiotics must be given within 4 h after injection of bacteria into a surgical site to prevent the aggressive level of infection that occurs when no antibiotics are administered.

Antibiotic prophylaxis entails administering the antibiotic appropriate for the potential microbial contamination before the surgical insult, at a high enough dosage to establish an appropriate bacteriologic titer [14].


With judicious use of antibiotics, the infection rates are known to be lesser [16, 18].

#### **Table 10.4** Indications for antibiotic prophylaxis

	- (a) Physiological—old age, obesity, malnutrition
	- (b) Disturbances in circulation—massive transfusion, recent surgery
	- (c) Disease related—poorly controlled diabetes, cancer, leukemia, alcoholic cirrhosis, end-stage renal diseases
	- (d) Compromised immunity—multiple myeloma, total body irradiation, splenectomy
	- (e) Immunosuppressants—cytotoxic drugs, glucocorticoids, azathioprine, cyclosporine


#### **Table 10.5** Classifcation of surgical wounds

#### **Table 10.6** Need for postoperative antibiotics



One must be vigilant in identifying cases where antibiotics are required for the success of surgery, as antibiotic usage and overusage have considerable risks [6, 7, 20, 21]—gastrointestinal disturbances, toxicity reactions, antibiotic resistance and superinfections, anaphylaxis, pseudomembraneous colitis, etc.

#### **10.3.1 Prophylactic Uses of Antibiotics in Maxillofacial Surgery**

Infection, one of the most common postoperative complications, can be prevented by the timely use of appropriate antibiotic. In spite of many studies in literature, a defnitive conclusion cannot be made regarding the need for antibiotic prophylaxis in maxillofacial surgery and, if needed, the dose required. The antibiotic prescription pattern is still hugely based on personal preferences and shows wide regional variation, which many a time is inappropriate. The drugs would be initiated either at an incorrect time, or would be continued beyond the time required, and this has greatly contributed to the emergence of resistant bacteria [6].

Prophylactic use of antibiotics should be evidence based taking into consideration the effectiveness and the possible adverse outcomes of antibiotic therapy. Moreover, a thorough knowledge of the likely organisms involved in the infection is needed to prevent the prescription of unsuitable antibiotics. Antibiotics, if needed, should have a spectrum of activity that involves streptococci, anaerobic Grampositive cocci, and anaerobic Gram-negative rods, which are considered the most pathogenic for oral infections and should be bactericidal and the least toxic agents available amoxicillin being the most common choice of the clinicians [12, 18].

The need for antibiotic prophylaxis and the preferable drugs for wisdom teeth removal, orthognathic surgery, dental implants, maxillofacial trauma, and in special circumstances like patients with diabetes mellitus, patients—pre- and postorgan transplant, rheumatic heart disease—valve replacements, oncological surgery & reconstruction, cleft surgeries, etc. are mentioned in the following sessions.

#### **10.3.2 Antibiotic Prophylaxis in the Surgical Removal of Wisdom Teeth**

Though one of the most commonly performed minor oral surgical procedures, the reported infection rate with the removal of mandibular third molars is ≤10% [22]. However, the rate can be as high as 25% when the patient's immunity is compromised [20]. The infection rate associated with the corresponding procedure in maxilla is quite low, <1% [20, 22]. The higher rate of postoperative infection in relation to mandibular third molar has been attributed to the reduced vascularization and the gravity-induced pooling of bacterialrich saliva.

The prophylactic use of antibiotics in wisdom teeth removal had been an issue of many debates. There are studies for [20, 23] and against [24, 25] the practice of antibiotic prophylaxis in third molar removal. Considering the potentially contaminating oral environment in which the third molar removal is carried out, it is reasonable to favor antibiotic prophylaxis. Moreover, since the postoperative infection and alveolar osteitis, an infammatory response whose etiology could be traced to bacterial contamination and fbrinolysis of the socket blood clot, cause debilitating pain and severe functional impairment, it is only prudent to consider the use of prophylactic antibiotics.

Studies have shown that preoperative administration of antibiotics reduces the postoperative infection when administered 1-2 h prior to the procedure [26, 27]. Amoxicillin/ amoxicillin—clavulanic acid is the widely used antibiotic in the prophylaxis for the surgical removal of impacted teeth [28] and when given as a single dose preoperatively is found to reduce postoperative infection and alveolar osteitis [21]. But certain other studies have failed to show a considerable difference between amoxicillin, clindamycin, metronidazole, and placebo in terms of postoperative infection rates [25]. Studies have found topical tetracycline [29], chlorhexidine irrigation [30],& metronidazole dressings [31]into the mandibular third molar sockets, effective in reducing the postoperative infection & the incidence of dry socket. Review of literature does not give defnite indication to use of antibiotics as prophylaxis in healthy patients or asymptomatic impacted teeth and in case of the removal of maxillary wisdom teeth [22].

Studies have advocated the use of antibiotic prophylaxis in immunocompromised patients to prevent infection after surgical removal of impacted teeth [22].

Two recent meta-analyses [28, 32] summarize the antibiotic prophylaxis in wisdom teeth removal (Table 10.7).

#### **10.3.3 Antibiotic Prophylaxis in the Placement of Dental Implants**

Dental implants play a crucial role in the successful restoration of missing dentition. The success rate of dental implants is high, with only 0-10% of reported failure rates [33]. However, risk of failure is high during the frst year after implant placement [34]. The implant surfaces can become colonized by oral and perioral microorganisms during surgery (perioperative contamination) [35]. This can lead to pain, swelling, bone loss, and eventually failure of implants. The failure of the dental implants is multifactorial (Table 10.8).

**Table 10.7** Antibiotic prophylaxis in wisdom teeth removal—Key points


**Table 10.8** Factors affecting the survival of implants [33, 34]


Hence all these local, systemic, surgical, and procedural factors contributing to implant failure should be eliminated before considering infection as the reason for failure [33].

Because of the morbidity associated with infection of the implants, antimicrobial therapy is routinely used with the aim of prevention of surgical site infection. Though by defnition, dental implant placement is a clean-contaminated surgery with 3–11% chances of infection, the infection rate can be brought down to about 1% by proper patient selection, attention to surgical details, and by judicious use of antibiotics [18].

There are studies supporting antibiotic use to reduce implant failures [33, 34] and studies that fail to show any added benefts of antibiotics against implant failurte [36]. Few other studies have observed similar failure rates for the implants with a single preoperative dose and routine use of antibiotic for 7 days [37].

The currently advocated dose of antibiotic prophylaxis for implant surgery is 2–3 g of amoxicillin 2 h prior to multiple implant placement, especially along with bone graft [33]. If the patient is allergic to penicillin group, 600 mg clindamycin should be given 1 h before surgery. For sinus augmentation, 1.2 g of amoxicillin/clavulanic acid starting day before the surgery is the prophylaxis of choice [33]. Chlorhexidine gluconate mouth rinses have been known to reduce the number of pathogenic microorganisms, by lysing the bacterial cell membranes, and by virtue of its substantivity, can get retained in the oral soft tissues and get released slowly for up to 12 h [30, 33]. The key points in the antibiotic prophylaxis for dental implants are given in Table 10.9.

### **10.3.4 Antibiotic Prophylaxis in Orthognathic Surgery**

Orthognathic surgical procedures aim to correct the facial deformities and malocclusion, thereby improving the functional disorders of the stomatognathic system. It is an elective procedure, usually carried out in young healthy adults. It is considered as a clean-contaminated procedure with a reported infection rate of 3–11% [18, 39]. But certain studies have reported the rate of infection after orthognathic surgery to be as high as 6–33.4% [39]. The postoperative infection was found to be related to poor oral hygiene and the habit of smoking.

The surgical site infections (SSIs) that develop can be incisional SSIs and organ and space SSIs [40]. Both types of SSIs can occur after orthognathic surgery and may develop within the frst few weeks after surgery. The development of SSIs increased the total length of hospital stay and expenditure. Though the potential for postoperative infections after orthognathic surgery is known for a very long time, a consensus has not yet been achieved with regard to the drug that is useful, the dose, and the duration of administration.

The specifc orthognathic procedure that has been associated with higher infection rate was mandibular sagittal split osteotomy, especially where a transbuccal approach had been adopted for fxation [38]. Increased rate of infection associated with mandibular procedures has been attributed to the diminished vascularity of mandible in comparison with maxilla and pooling of food and saliva along the vestibular incision line in the mandible. Till the incision seals off, oral microfora can freely enter the deeper tissues from the pooled saliva. Though concomitant extractions, especially of partially erupted mandibular third molars had been implicated as a risk factor for the development of postoperative infec**Table 10.9** Antibiotic prophylaxis in dental implants—Key points

*Care to be taken* [35]: Through oral prophylaxis & measures to improve oral hygiene Stabilize oral focus of infection Procedure in a well-monitored asceptic environment disinfection, draping, hand scrubbing, sterile gowns & gloves, sterile instruments Prevent contamination of implants with contact with skin, infected oral mucosa, & sinus lining Bactericidal antibiotic with coverage against pathogenic oral microfora [12, 18, 33] Preoperative administration of antibiotics—1 h before the procedure, twice the therapeutic dose [18, 33]—Amoxicillin 2gm, / clindamycin 600 mg 1 h prior to surgery Chlorhexidine gluconate rinses—hugely effective in controlling the immediate local infection [30, 33]. 1 *Only Chlorhexidine 0.12% rinse twice daily in healthy individuals* [33]

	- (a) Multiple implants with minimal tissue refection,
	- (b) Immediate extraction & implant placement,
	- (c) Socket bone grafting.
	- (a) Multiple implants with extensive tissue refection,
	- (b) Multiple extractions & implant placement,
	- (c) Bone grafting—allografts,
	- (d) Long duration.
	- (a) In medically compromised patients,
	- (b) Extensive tissue refection,
	- (c) Full arch implants,
	- (d) Block bone grafting—autografts,
	- (e) Indirect sinus foor lift procedures,
	- (f) Active periodontal disease.

tion, studies were not able to support or refute this [38, 41] Longer surgeries involving multiple/segmental procedures also show a higher rate of infections [12, 18, 38].

Use of various antibiotics has been proposed—penicillin [42], ampicillin [43], amoxicillin with or without clavulanate [43], clindamycin [42], or a member of the cephalosporin group [19, 41]. Literature fails to report a signifcant difference in the infection rate when using a penicillin or nonpenicillin group of antibiotics or among the various types of penicillins [18, 19, 44]. Based on the bacteriological studies, penicillin, amoxicillin, or amoxicillin—clavulanic acid or cephalosporins is commonly recommended in the preoperative antibiotic prophylaxis for orthognathic surgery [19, 38, 41–44].

The preoperative single dose of antibiotic increases the level of the drug in circulation prior to incision. Whether short-term antibiotics (single dose or dose × 24 h) [ 42] or extended-term antibiotics (for more than 24 h) [ 41, 43] is benefcial in the prevention of postoperative infection after orthognathic surgery is still a debatable question [19, 38, 41, 44].

#### **10.3.5 Is Antibiotics Needed when Bone Plates and Screws Are Being Inserted?**

One question that keeps on surfacing is whether prophylactic antibiotics are needed in cases where bone plates and screws are used to hold the bony segments together. Any foreign body inserted into the body, be it a medical device or implant, may elicit a foreign body reaction. Moreover, the microorganisms can colonize on the implant surface in a bioflm, while they are being inserted, and as the physical presence of the implants may compromise the blood supply to the region, thereby reducing the delivery of body's immune cells to the region and resulting in infections at the host –implant interface by normal fora with low virulence [45, 46]. The oral bioflm and its toxins, adhered to the surface of titanium plates and screws used for stabilization of osteotomy segments, could be a source of local or regional infectious complications [19]. Hence, the use of antibiotic prophylaxis is justifed.

*Take-home points regarding antibiotic prophylaxis in orthognathic surgery are mentioned in* Table 10.10*.*

#### **10.3.6 Antibiotic Prophylaxis in Maxillofacial Trauma**

In today's world of fast-moving vehicles and expressways, hundreds of thousands of people get involved in road traffc accidents. Head and face are among commonly injured body parts. Both the soft and hard tissues of the face may be involved in the trauma. Firearms, contact sports, and interpersonal violence are other reasons for facial injuries. The management of these injuries should follow protocols and be done in a systematic manner. With advances in anesthetic and surgical techniques and availability of better implant materials with favorable metallurgy, open reduction and internal fxation (ORIF) has become the norm. The reestablishment of form, function, & cosmesis is of paramount importance. To arrive at this goal, the probable complications of ORIF need to be prevented or managed correctly. Of the various complications reported, none has generated more interest and controversy than the occurrence of postoperative infection. By adhering to the standard surgical protocols and strict aseptic techniques, the occurrence of postoperative **Table 10.10** Antibiotic prophylaxis in orthognathic surgery—Key points

	- (a) Longer surgery;
	- (b) Short-term antibiotic prophylaxis;
	- (c) Extraction of a third molar during surgery;
	- (d) Greater number of osteotomies performed;
	- (e) Older age;
	- (f) Smoking;
	- (g) Poor oral hygiene;
	- (h) Compromised immune system.

infection can be brought down considerably. But the presence of the microorganisms in the oral cavity and facial skin and possible contamination from environment necessitate the consideration of antibiotics in the maxillofacial trauma management.

Though prophylactic antibiotics were considered essential in the management of maxillofacial trauma for many years [18], the evidence for this preventive intervention was weak and confusing. Among facial fractures, mandibular fractures are most commonly studied, because of the compound nature of the fractures, except in the ramus—condyle unit, where the fractures usually do not communicate with the external environment. Fractures of the mandibular condyles or Lefort fractures of maxilla are rarely infected when compared with the fractures involving mandibular angle, body, or symphysis [49, 50].

The decision to use antibiotic prophylaxis depends on whether the fracture is an open or closed type and whether it is going to be managed with open or closed reduction. Open procedures were four times more commonly prone to postoperative infections according to a few studies [41, 51, 53, 54], whereas certain other studies reported no difference between the patients treated with closed reduction and maxillomandibular fxation and those who underwent open reduction and internal fxation [54]. The microbiology of the infected fractures was mixed and responded to betalactam antibiotics well.

**Table 10.11** Antibiotic prophylaxis in maxillofacial trauma—Key points

	- (a) Longer surgery;
	- (b) Older age;
	- (c) Smoking;
	- (d) Poor oral hygiene;
	- (e) Compromised immune system.

Studies have shown that single dose of preoperative antibiotic prophylaxis is suffcient to prevent wound infection [51, 54]. If the surgery extends beyond the half-life of the antibiotic, the antibiotic can be redosed [51]. The need for postoperative antibiotics in the maxillofacial trauma too has been extensively studied [16, 49, 53, 55, 56]. These studies reported no statistically signifcant difference in the development of SSIs between the patients who had received perioperative antibiotics and those who had received extended antibiotics in the postoperative period.

Longer antibiotic usage has been advocated in the immunocompromised patients [32, 52, 56]. The habit of tobacco smoking was found to have a deleterious effect on the healing of mandibular fractures by inducing hypovascularity and prolonged infammation [54]. The other major factors, which contribute to the occurrence of SSIs, are poor oral hygiene, extremes of age and malnutrition [22, 32].

*Important points mentioning the need for antibiotics in the management of maxillofacial trauma are given in* Table 10.11*.*

#### **10.3.7 Diabetes Mellitus & Antibiotic Prophylaxis in Maxillofacial Surgery**

Diabetes mellitus is a metabolic disorder resulting in elevated glucose levels, due to inadequate insulin secretion (type I) or reduced insulin secretion with an accompanying insulin resistance (type II). Diabetic patients pose a special challenge to the surgeon as the balance between the insulin they can secrete and the hyperglycemia induced by surgical stress-adaptive hormones catecholamines, cortisol, growth hormone, and glucagon is lost. Patients, who are nondiabetic, usually are able to handle this glucose overload effectively, whereas diabetic patients may have issues resulting in cardiovascular complications, infection, and reduced rates of wound healing. Moreover, the defective polymorphonuclear leukocytes function and macro- and microvascular dysfunction resulting in compromised local circulation increases the susceptibility to infections [57]. With the vast microbiological colonization of the oral cavity, it has always been assumed that maxillofacial surgical procedures carry a high risk of infection and prolonged or delayed wound healing. The guidelines as to the prophylactic use of antibiotics in diabetic patients had been vague as "….are more prone to infection necessitating routine antibiotic prophylaxis for all maxillofacial procedures" [58].

In many of the literature surveys, authors have noted that well-controlled diabetic patients are at no increased risk of postoperative infection than normal healthy patients and delayed wound healing is not a pressing concern due to the rich vascularity of the region [59, 60]. Antibiotic prophylaxis is warranted only in conditions where a normal patient also would beneft from it. Poorly controlled diabetic patients would require normalization of their hyperglycemic state prior to elective procedures. In emergency situations, antibiotic prophylaxis prior to the surgical incision is desirable and attempts should be made to control the glycemic level during the peri- and postoperative period [58–60].

#### **10.3.8 Antibiotic Prophylaxis in Head and Neck Oncology**

Head and neck oncology patients usually require a major surgical procedure +/− with radiation therapy. The surgical site tends to be large, the surgical time and postoperative immobilization period longer. The surgical management attempts at removal of the tumor, clearance of the neck nodes, and involves an additional surgical site from where fap is harvested for reconstruction—either microvascular faps or pedicled ones [61]. The large wound area exposed to local fora of the oral cavity and the skin is at risk of wound contamination and infection. Nosocomial infections are known to run a protracted course and pre-existing general comorbidities further increase the morbidity and, thus, the hospital expenses associated with these surgeries.

The reasons for increased infection rate are mainly the number of procedures carried out in the same operation (excision, neck dissection, tracheostomy, and distant fap harvest), the pooling of saliva due to diffculty in swallowing, leading to aspiration, and the inability in obtaining a watertight closure when the fap is inset in the recipient bed leading to salivary leak and contamination of neck wounds with saliva [62, 63].

**Table 10.12** Key points in oral oncology & antibiotic prophylaxis


The need for antibiotic prophylaxis is well established in the oncologic surgery, but the need for a long postoperative course of antibiotics is still debated upon. There are studies, which have shown benefts of prolonged antibiotics in preventing postoperative infections like pneumonia, urinary tract infections, sepsis, and SSIs in patients who had oral squamous cell carcinoma [64], and there are studies, which have shown no extra benefts of prolonged postoperative antibiotics [63, 64].

Escherichia spp. and Staphylococcus spp. are predominantly responsible for the infections and in 72% were sensitive to ampicillin & sulbactum [62].

*A few key points, which would be benefcial in making a decision, are given in* Table 10.12*.*

#### **10.3.9 Antibiotic Prophylaxis in Cleft Surgeries**

Orofacial clefting is one of the more common congenital anomalies and cleft lip & palate deformity is the most common among them. Management of cleft lip & palate deformity involves staged procedures and spans over 12–16 years. The management aims at correction of the deformity so that function and cosmesis are restored as much as possible and the psyche of the individual is minimally scarred. Postoperative infections can result in wound breakdown, poor speech & esthetics, and nasal regurgitation of food in cleft lip and palate patients.

Various authors had reported on obtaining swabs from nose and oral cavity to identify the possible pathogens and using antibiotics according to the culture reports before cleft lip and palate repair [65–67]. The pathogenic bacteria isolated from the swabs were Staphylococcus aureus and beta hemolytic streptococci [67]. But later studies demonstrated that there were not many differences between the group that underwent swab acquisition and corresponding antibiotics therapy and the group that didn't receive any antibiotics in terms of postoperative complications [68]. The rate of complications was found to be independent of the potential pathogens in the mouth [65].

*Factors, which have been implied as contributing factors to wound dehiscence, are given in* [66, 67] Table 10.13*.*

**Table 10.13** Factors contributing to wound dehiscence in cleft surgeries


In a recent prospective study, Azner et al. (2015) noted a statistically signifcant reduction in the incidence of palatal fstulas with 5 days of postoperative antibiotics [69]. But 80% of their control group, who had received no postoperative antibiotics, too healed without any complications. Both study and control groups had received a single dose of cefuroxime 30 mg / kg body weight, before incision. The use of one dose of antibiotics before incision has been advocated by other authors also and may be more effective in preventing complications related to wound infection than a prolonged course of postoperative antibiotics [68].

#### **10.3.10 Organ Transplant and Antibiotic Prophylaxis**

The concept of organ donation had always excited mankind. Twentieth century saw developments that made the dream of replacing a diseased organ with a healthy one a reality. Understanding the human immunology and the development of powerful immunosuppressant drugs laid the foundation for modern transplant medicine, making transplantation of kidney, liver, lungs, and heart a successful treatment option. As the transplant science advanced, so did the numbers and life span of transplant patients and their need for dental/maxillofacial surgical procedures. As these patients are on immunosuppressants, they are more prone to opportunistic infections and their sequel. Hence, care must be given to treat or remove the existing/potential sources of infection before the transplant procedures.

In a pretransplant patient, the need for maintaining oral hygiene should be stressed upon. The treating physician should be consulted with regard to the ftness to undergo the planned procedures and the safety of using any drugs if required. Drugs, which have a hepatic metabolism or renal clearance, should be used with caution in patients with compromised liver or kidney function. The selection of antibiotics is made after careful evaluation of the existing pathology and the chances of spread of infection with the planned dental treatment.

In the immediate post-transplant period—the frst 3 months post-surgery, the graft, and the patient are very vulnerable to any insult—graft anastomoses are susceptible to endarteriris due to bacterial colonization as they are not yet **Table 10.14** Key points—organ transplant and antibiotic prophylaxis

	- 1. Elimination of potential focus of infection,
	- 2. Oral hygiene,
	- 3. Liver / kidney friendly drugs.

Post-transplant patients:

	- 1. Only emergency procedures,

3 months postop—noninvasive elective procedures 6 months postop—invasive elective procedures under antibiotics Beta-lactam antibiotics - relatively safer to be used in renal and hepatic transplant patients [72]

No consensus on minimally invasive procedures in patients with meticulous oral hygiene [71]

fully epithelialized. Hence, only emergency procedures should be done. Any acute orofacial infection developing should be managed aggressively, surgical drainage, culture and sensitivity of the organism, and appropriate antibiotics would be required [70]. After 3 months, elective, noninvasive procedures can be carried out. Since the patients who have undergone organ transplantation are immunosuppressed and are at high risk of infection, prophylactic antibiotics need to considered for any invasive dental procedures, even after 6 months. Beta-lactam antibiotics are relatively safer to be used in renal and hepatic transplant patients [71]. But for those with meticulous oral hygiene, there is no consensus regarding the need for antibiotic prophylaxis for minimally invasive procedures [71]. The decision to use antibiotics should be done on a case-to-case basis.

*Important points to be kept in mind while contemplating antibiotic prophylaxis in organ transplant patients are given in* Table 10.14*.*

#### **10.4 Infective Endocarditis**

Bacterial endocarditis, a rare but life-threatening condition, was initially described by Lewis & Grant in 1923 [72]. They suggested that bacteria released into the blood stream after a dental procedure colonize on the heart valves or the endocardium. The bacteremia associated with infections of skin and soft tissues, genitourinary tract, and gastrointestinal tract are also known to result in infective endocarditis (IE). Bacteria can gain direct access to the bloodstream through the indwelling catheters. The American Heart Association (AHA) came up with the frst guidelines to reduce the risk of IE following invasive procedures in 1955 [73]. The AHA guidelines have been updated regularly since then and the latest one was released in 2007 [74]. The 2007 guidelines categorized cardiac conditions into having a low risk, moderate risk, and high risk of developing IE and advocated the use of antibiotic prophylaxis only in

**Table 10.15** High-risk cardiac conditions, which require antibiotic prophylaxis [75]


high-risk-category patients (Table 10.15) who were to undergo dental procedures that involved the manipulation of gingival tissues or the periapical region of teeth or incision of the oral mucosa.

The guidelines prescribed a single dose of antibiotic 30-60 minutes prior to the procedure—Amoxicillin 2 g PO, Cephazolin/Cephtriaxone 1gm IV/IM, or Clindamycin 600 mg PO/IM/IV, depending on whether the patient is unable to take oral preparations or is allergic to penicillin or not [74]. The reason for the revision of the antibiotic policy was predominantly the observation that IE is more likely to result from transient bacteremias caused by routine daily activities, like chewing food, and by regular oral hygiene care. The authors concluded that maintaining optimal oral hygiene is more important in reducing the risk of IE and the adverse effects of antibiotics exceeded the benefts of antibiotic prophylaxis. The British Society for Antimicrobial Chemotherapy (BSAC) also recommend antibiotic prophylaxis only in those who have a history of healed IE, prosthetic heart valves, and surgically constructed conduits [75]. The advice to the patient is to concentrate on achieving and maintaining meticulous oral hygiene as this has been found to reduce the risk of IE. Similar observations were made by the National Institute for Health and Care Excellence (NICE) [76] and the European Society of Cardiology (ESC) [77].

There has been a rising concern over the potential for an increased incidence of IE and a worse prognosis for the diseased since the guideline changes by the AHA, NICE, ESC, BSAC. Several studies have been carried out to assess the impact of these changes on the disease incidence in adults and pediatric population. Whereas earlier studies showed not much difference pre- and post-guideline changes in incidence [78], recent studies have noted a defnite increase in the incidence of IE post-guideline changes [79]. Sakai et al. in 2017, though noting no change in the incidence and severity of IE in pediatric patients, pre- and post- guideline changes, reported an increase in the viridans group streptococci (VGS)–induced IE in older age group [79]. The data from these studies point to the need for further investigation into the effectiveness of 2007 guidelines, though it has been argued that the increase in IE incidence may be related to the increasing life span of the patients with congenital heart diseases and prosthetic devices and increase in the number of invasive procedures being performed on them.

#### **10.5 Postoperative Pain Management in Maxillofacial Surgery**

The International Association for the Study of Pain (IASP) defnes pain [80] as: "an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage."

Pain is the most debilitating postoperative symptom and its control or elimination is usually the primary goal in postoperative management of a patient. Inadequate pain control resulting in patient distress is the most common cause of an increased length of hospital stay. The postoperative pain, infammatory in character, is a temporary one persisting only until healing. But severe, acute, repetitive, postoperative pain increases the risk of the pain becoming chronic and may lead to allodynia and hyperalgesia [81]. Orthognathic surgery patients may continue to feel the pain even after 1 year of surgery [82] . Hence, appropriate pain management is critical to achieving a successful surgical outcome. Prevention of pain is more effcient than the treatment of pain. For this, an understanding of basic pathophysiology behind pain mechanism is important.

#### **10.6 Pathophysiology of Postoperative Pain**

Pain is initiated by the excitation of nociceptors, receptors that respond to noxious - mechanical, thermal, and chemical stimuli. Sensory nociception is disproportionately greater in the head and oral cavity when compared with other parts of the body. Often a patient's overanxiety about undergoing an elective surgery would result in an increased intensity of the perceived pain [83].

Surgical insult results in tissue trauma and initiates a chain of infammatory events, causing a release of chemical substances responsible for nociceptor excitation. Trauma releases tissue phospholipids, which are converted into arachidonic acid due to the action of phospholipase A2 and the consequent conversion of this substance into prostaglandins, prostacyclins, and leukotrienes due to the action of cyclooxygenase (Cox) and lipoxygenase enzymes. These locally released chemical mediators sensitize the nociceptors and cause vasodilatation, with a consequent increase in cell permeability and edema. Trismus after a maxillofacial surgery is a sequela to the postoperative edema around the masticator muscles and is aggravated by pain [84]. The physiological responses to tissue trauma, pain & edema, can be managed successfully by inhibiting the pathways that produce the chemical mediators, before the occurrence of surgical trauma (Fig. 10.1).

Similarly, mechanisms, which enhance the endogenous pain inhibition and anxiolysis and patient education, can

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 10.1** Pharmacologic interventions in arachidonic acid metabolism

modify cortical processing of pain perception [85]. All these measures collectively lead to an effcient postoperative pain management.

#### **10.6.1 Pre-Emptive Analgesia**

Postoperative pain has a protective function as it allows for undisturbed healing of the operated tissue by restricting movements. The aim of postoperative pain management is to reduce pain signifcantly, but not to eliminate it completely [86]. Overall postoperative pain experience could be reduced by paying attention to lessening of the pain during the surgical procedure itself. Pre-emptive analgesia is defned as an antinociceptive treatment that is started preoperatively and is active during surgery, reducing the physiological consequences of nociceptive transmission [87]. Since the introduction of the concept of pre-emptive analgesia by Woolf in 1983, many attempts to reduce the pain by using analgesics and adjunctive measures, such as the administration of long-acting local anesthesia, corticosteroids, and intraoperative nitrous oxide analgesia, have been reported [88]. These should be given before the surgical incision and should be timed so that the maximum plasma concentration of the drug is reached at the time of surgical incision. This will prevent the release of the infammatory mediators, giving immediate analgesic effects. The use of IV analgesia has an added beneft over oral administration, as following oral administration analgesics reach maximum concentration after 1.5 h, whereas intravenous administration results in maximum concentration in a short period.

Numerous studies have shown benefcial effects of the preoperative administration of ibuprofen with paracetamol [89] piroxicam [90], ketorolac [91], meloxicam [92], parecoxib [93], and dexamethasone with rofecoxib [94]. There had been contradictory reports also in which the authors fail to fnd a clear-cut beneft for pre-emptive NSAIDS [95, 97]. The authors state that the pre-emptive intake of analgesics should not be used in all patients as a general rule. They base their recommendations on the lack of enhanced analgesic effects and on the potential adverse effects such as increased intraoperative bleeding [95].

Despite the confusion regarding the effectiveness of the pre-emptive analgesia, it has been strongly advised to start systemic analgesics before the local anesthesia effect wears off and/or give a nerve block with long-acting agent like bupivacaine [86].



#### **10.6.2 Postoperative Pain Management**

Postoperative analgesia has traditionally been achieved by prescribing analgesics with instructions to take as and when necessary. Experience with this approach was that many patients would not take the medication until the onset of signifcant pain. This practice earned the maxillofacial surgery the reputation of being an extremely painful one. The truth is that the postoperative pain management can be successfully achieved by carefully planning the delivery of the pain control measures at the appropriate time in the peri- and postoperative periods.

Pain perception is a subjective feeling, which is amplifed by many factors and identifcation of the patients who are "at risk" for the development of severe postoperative pain would help in charting out an individualized management plan [97] (Table 10.16).

Identifying predictors of postoperative pain in patients before surgery, educating patients at the preoperative visit regarding the expected pain, and presenting the postoperative pain management plan will prepare patients better and relieve some of their anxiety regarding the procedure. An increased awareness of the importance of the psychological factors will allow more effective pain management.

#### **10.6.3 Pharmacological Management of Postoperative Pain**

The postoperative pain management is usually done with opioids and nonsteroidal class of anti-infammatory drugs.

#### **10.6.3.1 Opioids**

Opioids have been in use for moderate-to-severe pain relief for a long period. References to opium poppy can be found in Sumerian and Egyptian culture, as back as 300 BC. The opium poppy, Papaver somniferum, gives rise to more than

#### **Table 10.17** Opioid analgesics


**Table 10.18** Side effects of opioid analgesics


20 different alkaloids [100]—morphine and codeine being the main ones (Table 10.17).

Opiate alkaloids exert their action by acting on the opioid receptors- μ, κ, δ (mu, kappa, and delta), which otherwise provide sites for activation of endogenously released opioid substances - beta-endorphins, enkephalins, and dynorphin compounds, which produce endogenous central analgesia. Opiate agonists produce analgesia by inhibiting excitatory neurotransmission of substance P, acetylcholine, noradrenaline, and dopamine.

Unfortunately, opioid use, even when prescribed for short periods, comes with certain risks (Table 10.18).

For these reasons, most opioid agents used in outpatient postsurgical pain management are formulated in combination with non-narcotic analgesics [104]. This formulation potentiates the analgesic effects of the individual agents within the formulation while minimizing the side effects of pure opioid administration [105].

#### **10.6.3.2 Tramadol**

Tramadol, a synthetic substance with both opioid and nonopioid properties, is structurally related to codeine. It exhibits antidepressant and anxiolytic-like effects, in addition to analgesic action. It is considered safe for long-term use unlike NSAIDs with their potential for impairment of renal function and gastrointestinal complications, and with respect to other opioid medications for its low addiction rate and favorable safety profle. The most common adverse effect of tramadol is nausea and vomiting, especially with oral administration. Tramadol is contraindicated in patients with poorly controlled epilepsy because of its excitatory serotonergic effects. It is available either as a single drug or in combination with acetaminophen. Submucosal injection of tramadol at the extracted site of third molars has been proven effective in reducing the postoperative pain [106]. It suffers no side effects of systemic administration.

#### **10.6.3.3 Nonsteroidal Anti-Infammatory Drugs (NSAIDs)**

NSAIDs have been in use for the treatment of pain, fever, and infammation since late 1800 [107]. The antiinfammatory and analgesic properties of these drugs without the side effects and the addictive potential of opioids have made this class of drugs the frst choice in ambulatory dentoalveolar procedures (Table 10.19).

They are a group of chemically heterogeneous compounds with several similar pharmacologic actions like antiinfammatory, antipyretic, analgesic, and antiplatelet actions. They primarily act at the site of tissue injury by inhibiting the synthesis of prostaglandins within the endoperoxide pathway (Fig. 10.1).



Historically, majority of the NSAIDs were nonselective COX inhibitors with side effects related to the blockade of cytoprotective prostanoids - gastric irritation, increased bleeding time, and renal impairment. Over the past few years, selective COX2 inhibitors have been developed, which block the COX-2–mediated prostaglandins while maintaining the physiologically benefcial effects of the COX-1 isoenzyme [108].

Overall, NSAIDs are safe drugs to be used in the management of acute/postoperative pain. Parenteral use of NSAIDs has shown to be more effective in pain control [109]. About 60% of the patients would respond to the frst NSAID, and the rest would show beneft with another NSAID. Ibuprofen is a widely used NSAID, with proven effcacy [110]. About 5% people experience "aspirin-sensitive asthma," probably due to the inhibition of Cox enzyme. Because of the probable mechanism of inducing asthma, it is felt that selective Cox 2 inhibitors may not cause asthmatic attacks [111].

#### **10.6.3.4 Paracetamol**

Paracetamol or acetaminophen is a widely available analgesic with an antipyretic action. It acts by inhibition of the COX-3 isoenzyme, reducing the production of prostanoids in the central nervous system. This central inhibition explains the antipyretic action of paracetamol. Paracetamol shows an excellent result in relieving mild-to-moderate pain relief and fever [112]. When used in combination with other analgesics, it shows superior analgesic power, thereby reducing the dose of opioids required [96].

#### **10.6.4 Guidelines to the Use of Analgesics**

Since there is no defnitive evidence or clear algorithms, the selection of NSAIDs, to a large extent, depends on clinical experience and side effects. Patient convenience and cost also play a minor role in the selection of analgesics.

Laskarides (2016), in his review on control of dental pain, puts forward his observations (Table 10.20) [113].

#### **10.6.4.1 Analgesic Ladder**

WHO initially described the concept of "pain ladder" in their guidelines for the use of drugs for the management of cancer pain [114]. The concept has been now accepted in the management of all types of pain [104]. The concept is based on the use of frst line of drugs for the mild-to-moderate pain and then climb the ladder to more potent drugs if pain still persists. Please see chapter on postoperative care, to view the analgesic ladder.

**Table 10.20** Key points in using analgesics


```
combination therapy [113].
```
#### **10.6.4.2 Preventive /Protective/Multimodal Analgesia**

Pain is multifactorial in origin and multiple techniques and drugs may be required to achieve control over it. The simultaneous use of different classes of analgesics and techniques has been called preventive, protective, or multimodal analgesia [115]. This approach uses a combination of drugs that act at different sites of action on the nervous system by different mechanisms to prevent peripheral and central sensitization of pain. It results in additive analgesia, but with lowered side effects than the single agents when used alone. Intraoperative local anesthesia followed by a range of analgesic drugs have been found to be effective in controlling the pain in day cases and reduces the need for opioid analgesics [116].

The complex surgeries involving multiple surgical sites as in head and neck oncological cases and craniofacial surgeries would gain hugely from the administration of multimodal analgesia. Multimodal analgesia can be successfully achieved by combining the currently available analgesic modalities (Table 10.21).

#### **10.6.4.3 Patient-Controlled Analgesia (PCA)**

Patient-controlled analgesics are intravenous agents, delivered through a microprocessor-controlled infusion pump, in which a predetermined dose can be delivered by the press of a button, and a lockout time can be set, so that patient cannot overdose himself [119]. PCA is usually used in patients who are distressed at the thought of postoperative pain. Fentanyl, morphine, & combinations are the usually used medications. Though PCA was initially thought to reduce the patient pain perception, thereby reducing the length of stay (LOS), studies have failed to show any statistically signifcant difference **Table 10.21** The analgesics and adjuncts that can be used in multimodal analgesia [117]


in the pain score and the LOS between the PCA group & non-PCA group of patients after orthognathic surgery [119, 120]. This could be attributed to the fact that the subjects in the PCA group were predominantly bijaw surgery patients for whom the surgical time was longer and the surgical procedure resulted in more tissue injury. But from patient's perspective, PCA is the preferred method, as they feel in charge of their own pain control [121].

#### **10.7 Corticosteroids in Maxillofacial Surgery**

When tissue damage occurs as a result of injury, body's natural defense mechanism is infammation and body tries to heal. But overt infammation results in pain, edema, and limitation of movement, trismus. These symptoms may not be evident immediately, but peak after the second day, returning to normal by seventh postoperative day [122]. Corticosteroids suppress the infammation (Fig. 10.1) by interfering with the capillary dialatation, fuid transduation, fbrin deposition, leukocyte migration, and phagocytosis. Under normal nonstressful conditions, the body produces approximately 15 to 30 mg of hydrocortisone/cortisol per day. During stressful situations, 300 mg of hydrocortisone per day can be produced. Generally speaking, to suppress infammation, the dose of exogenous corticosteroids must exceed the normal physiological amounts of hydrocortisone released [123].

The frst reported clinical use of the anti-infammatory properties of corticosteroids was in the treatment of rheumatoid artritis [124], following which its effcacy was tried in maxillofacial surgical procedures. The use of steroids and their effectiveness have been extensively studied in the third molar surgeries—the most commonly performed maxillofacial surgical procedure [125]. Markiewicz et al. noted that postoperative fndings of swelling, trismus, and pain were signifcantly lower in the group who received corticosteroids, than in the control group in the immediate postoperative period (1–3 days) [126].

The use of dexamethasone and methyl prednisolone, in controlling the postoperative sequel of third molar surgery when these drugs are administered via parenteral [127], oral [128] submucosal [129, 130] and topical [131] routes, has been reported.

*Studies have evaluated different formulations, dosages, and routes and sites of administration of corticosteroids, without any consensus*. (Table 10.22).

Dexamethasone has a longer duration of action than methylprednisolone and is considered more potent.. Intralesional/intramasseteric injection of dexamethasone is found to be better than the intravenous or parenteral administration in controlling postoperative edema & trismus and has an additional beneft of being given through an alreadyanesthetized area [130, 132].

Almeida et al. (2019) [133] failed to note any beneft of submucosal injection of steroid at the local site. Authors gave the reason for this as the displacement of the medicine from the local site when mucoperiosteal fap is refected to expose the tooth. Similarly, the merits of intravenous administration of steroids perioperatively in major surgeries have been questioned by a group of authors [134]. Kainulainen et al. [134] reported infectious complications—pneumonia, gastrostomy site infections, & surgical site infections in oncological cases.

Though the reduction of edema brings about some reduction in discomfort, steroids alone do not have a clinically signifcant analgesic effect [130, 135] This has been attributed to the inability of the steroids to block the production of neurotransmitters by the injured tissues and central sensitization to pain. The combination of dexamethasone with tramadol or diclofenac sodium has been proven more effective in controlling postoperative pain and trismus, as opposed to corticosteroids alone [136]. Alexander & Throndson [127] summarized few salient points with regard to usage of steroids, based on their review (Table 10.23).


**Table 10.22** Commonly used steroids with their anti-infammatory potency& equivalent dose and commonly used doses [1]

**Table 10.23** Summary of corticosteroid use in maxillofacial surgery

	- Active tuberculosis Active viral / fungal infections Active acne vulgaris Primary glaucoma Patients with psychoses

#### **10.8 Conclusion**

Maxillofacial surgical practice involves use of many therapeutics to facilitate the treatment or promote healing. A careful evaluation of these drugs or reported literature, a detailed knowledge about their side effects, interactions with other chemicals, and how any alterations in the patient's physiology enhance or suppress the mechanism of action of these drugs is needed before their use or prescription. It is always prudent to remember that no medicine is without side effects and the benefts of using them should be weighed against the risks involved.

#### **References**


ity in isolates from orofacial odontogenic infections. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2000;90:600–8.


ing infectious complications in orthognathic surgery. Cochrane Database Syst Rev. 2015;1:CD010266.


#### **Additional Reading**

*Odontogenic microbiological spectrum.*


*Antibiotic prophylaxis*.

Moreno-Drada JA, Garcia-Perdomo HA. Effectiveness of antimicrobial prophylaxis in preventing the spread of infection as a result of oral procedures: a systematic review and meta-analysis. J Oral Maxillofac Surg. 2016;74:1313–21.

*Antibiotics in third molar surgery*.


*Antibiotics in implants*.

Chrcanovic BR, Albrektsson T, Wennerberg A. Prophylactic antibiotic regimen and dental implant failure: a meta-analysis. J Oral Rehabil. 2014;41:941–56.

*Antibiotics in orthognathic surgery*.

Bentley KC, Head TW, Aiello GA. Antibiotic prophylaxis in orthognathic surgery: a 1-day versus 5-day regimen. J Oral Maxillofac Surg. 1999;57(3):226–30. Discussion 230-2


*Steroids in third molar surgery*.


*Steroids in orthognathic surgery*.

Dan AEB, Thygesen TH, Pinbolt EM. Corticosteroid administration in oral and orthognathic surgery: a systematic review of the literature and meta-analysis. J Oral Maxillofac Surg. 2010;68:2207–20.

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## **Wound Closure and Care in Oral and Maxillofacial Surgery**

Ravi Veeraraghavan

### **11.1 Wound Management**

Management of soft tissue wounds needs a careful assessment of the wound, a good understanding of wound types and healing as well as adequate knowledge and skill for wound care. The various steps in wound care include cleansing and debridement, hemostasis, tetanus immunization and antibiotic medication and wound closure.

Wound closure can be accomplished in diverse ways, but suturing remains the mainstay. A wide variety of materials are available for wound suturing. One has to choose the right material and technique depending on the wound type and closure needs. Alternate techniques such as staples, tapes and adhesives are fast gaining popularity.

Wounds are treated by


## **11.2 Wound Closure**

Artifcial closure of the wounds is required if signifcant connective tissue is exposed. Wound closure leads to faster wound healing with reduced complications. Even though suturing is the mainstay of wound closure, other alternatives are fast gaining popularity.

R. Veeraraghavan (\*)

### **11.2.1 Purposes of Wound Closure**

Before going into the intricacies of material selection and techniques of wound closure, one needs to be clear about the actual need for artifcially closing a wound. The main indication for wound closure is signifcant exposure of connective tissue. In general, there are fve reasons behind the concept of wound closure.

1. *Healing by Primary Intention*

This is the most important purpose of wound closure. The open wounds, which are likely to heal by secondary intention, are made to heal in a 'more' primary manner by the intervention of wound closure. This hastens the healing process and also reduces scar formation, with resultant advantages in aesthetic and functional facets.

2. *Coverage of Deep Tissues*

When the epithelium is breached and connective tissue is bared, it exposes the inner tissues to mechanical and biological threats. This threat becomes even more serious when deeper structures such as the viscera or bone is exposed.

3. *Prevent Contamination*

An open wound is under constant attack by the pathogenic microorganisms, more so in the oral cavity. Such relentless contamination is likely to lead to a full-blown infection and/or delayed healing. Sooner the wound is closed, the lesser the risk of major contamination.

4. *Haemostasis*

This is not one of the primary purposes of wound closure. But sutures may help in impeding blood loss by preventing mechanical disturbance to the clot.

5. *Prevention of Dead Space*

If only the superfcial cutaneous sutures are placed over a deep wound, a dead space can result beneath the surface. This condition usually leads to wound breakdown and/or wound infection. Dead space is prevented by closing the deep tissues in multiple layers.

**11**

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 217

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_11

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_11) contains supplementary material, which is available to authorized users.

Department of Oral and Maxillofacial Surgery, Amrita School of Dentistry, Ernakulam, India

#### **11.3 Wound Suturing**

Suturing is the process of wound closure by holding the edges of the wound together using a thread. This thread, called a 'suture', is used to approximate the wound edges together and to hold them in position till the tissue healing is suffciently advanced to maintain themselves in the corrected anatomic position and alignment to each other. The surgeon uses a 'suture needle' to pass the thread through the tissues on either side of the wound so as to hold the separated edges in the proper position.

#### **11.3.1 Suturing Instruments**

Apart from the suture thread and needle, some instruments are used to perform the suturing process. Commonly used instruments include a needle holder, a tissue holding forceps and a pair of scissors.

#### **11.3.1.1 Needle Holder**

The needle holder (needle driver) is the primary instrument used for suturing. Similar to a haemostat, it is used to grasp and manipulate the suture needle to which the thread is attached. A needle holder has three parts—a pair of beaks, a joint ('pivot') and a pair of handles with rings. Many designs are available, examples being Webster, Halsey and Mayo-Hegar. Most designs have a serrated or cross-hatching pattern of teeth for the beaks. This helps to grip the needle securely without damaging it. A locking mechanism similar to haemostats is present to lock the needle grasp.

The classical way to hold the instrument is to engage the handle-rings with the thumb and the fourth fnger. The middle fnger is used for support and the index fnger is used to direct or orient the instrument in the required direction. Alternatively, while suturing on tough tissues, one may be 'palmed', i.e. may be held against the palm with fngers around. While palming the needle holder, some surgeons still rest the fourth fnger lightly in the handle-ring.

#### **11.3.1.2 Tissue Holding Forceps**

The pickup forceps are used to delicately handle and manipulate the wound edge which is being sutured. The fnetoothed Adson forceps is the workhorse for most interior and cutaneous wound closures. The forceps is held in the nondominant hand and is used to grasp, lift and evert the wound edge so that the surface is made more amenable to a perpendicular needle entry. Fine skin hooks may also be used for the same purpose.

#### **11.3.1.3 Suture Cutting Scissors**

The suture cutting scissors is used to cut the suture thread tags after the knot is tied. It is also used to cut the thread during suture removal.

These scissors should be differentiated from scissors used for cutting tissue. Many of them have specifcally designed blades and tips, which are uniquely shaped to lift and grasp up the handing tags or the tied suture thread away from the tissue and to cut it safely without injuring the tissues. Short and long versions are available. The tip may be straight or curved and may have a sharp slot for the thread to be cut. Some manufacturers have incorporated a cutting component in the needle holder itself, using which the surgeon can cut the suture tag without switching instruments.

#### **11.3.2 Suture Needles**

The suture needles help to pass the suture threads through tissues. In ancient days, needles were made of natural materials such as bones, ivory, horns, wood or thorns. In fact, eyed needles from as early as 30,000 AD have been unearthed. Later, metals such as silver, copper and aluminium bronze were used. The modern needles are diligently shaped and contoured as per use and are smooth and strong so that they withstand the stresses of suturing and least traumatic to tissues at the same time.

The suture needle has three parts: the tip, the body and the suture attachment. Made of stainless steel or carbon steel, they are thin, smooth and sharp, designed to pass through tissues with ease (Fig. 11.1).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 11.1** Parts of suture needle

#### **11.3.2.1 Needle Shape**

The suture needles are usually curved as an arc of a circle. Straight needles, though available, have very limited practical applications. The curvature is described as the span of the arc, in terms of ¼, 3 /8, ½ and 5 /8 of a circle. Most of the regular suturing in oral and maxillofacial surgery is done with half circle needles. A smaller arc such as 3 /8 can be used for suturing fat skin surfaces. Longer arc, i.e. 5 /8 circle, needles are used in narrow tunnelled surgical felds such as in cleft palate or inside the nose (Fig. 11.2).

The cross section and the tip of the needles can be widely varied. Depending on these aspects, the suture needles can be.


Round bodied needles are generally used to suture viscera and other internal structures such as muscle and fascia. It can also be effective on non-keratinised mucosa. The tip of the round-bodied needle can be blunt or sharp. The blunt tip needle is specifcally used in the inner abdominal wall and in friable tissues. The sharp tip is used for most other purposes. But even the sharp tip is hard to pass across the skin and keratinised mucosa. The shape of the 'cutting' needle overcomes this problem. In the cutting needles, the needle cross section is a triangle, with the inner curve side being pointed

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 11.3** Needle cross section of a conventional cutting needle

and the outer convex side fat. This shape enables the needle to 'cut' through the dense tissues to make the needle passage easier. But the cutting design presented a new problem. Even under minimum tension, the needle behaved like a knife, and the sharp edge often tended to lacerate the tissue resulting in a 'cut-through' of the wound edge. This was solved by the reverse-cutting design, wherein the inner curve is fat and the outer curve is pointed. This helps to retain the cutting nature while avoiding the risk of wound edge laceration. In oral and maxillofacial surgery, the tissues encountered may be keratinised (skin, gingiva and palate) or non-keratinised (buccal mucosa, foor of mouth and lips). Mostly, reverse-cutting needles are now being used since they are well-suited to pass through all oral tissues without causing inadvertent tears.

#### **11.3.2.2 Needle Size**

The suture needle size generally depends on the size of the suture. In general, smaller the suture size, smaller the needle. It is important to recognise the various dimensions of a needle.

The 'needle length' refers to the end-to-end measurement along the curve of the needle. The straight line distance from the tip to the other end is called 'chord length'. The chord length determines the bite-width of the needle in the tissues. The bite-depth into the tissue is defned by the 'chord diameter' which is perpendicular from the chord length to the centre of the needle body. Needle diameter and needle radius are dimensions which refer to the cross-sectional thickness and not to the needle curve.

#### **11.3.2.3 Eyed vs Swaged Needles**

The eye of the needle is a small hole at one end for attaching the suture thread. This necessitates an increase in the needle thickness at the attachment end, increasing the risk of potential tissue trauma. The suture is passed through the eye, and may then be tucked or tied for better retention. Both tucking and tying further increases the tissue drag and causes additional trauma. The attached suture now follows the needle through the tissues. The eyed needles are cheaper and can be reused after resterilisation.

Modern suture needles do not have an eye. Instead, the suture thread is sealed inside the needle for a permanent attachment. This mechanism, called 'swaging', reduces the tissue trauma signifcantly as the needle diameter is not increased for thread attachment. Further, only a single thread strand passes through the tissue at all times. So these needles are often called 'atraumatic needles'. The swaged needle with thread is available as a sterile pack, and cannot be reused.

#### **11.4 Suture Thread**

Many different types of suture threads are available for use. Each type has its specifc benefts and indications for application (Table 11.1).

A basic classifcation divides them into 'natural' and 'synthetic'. Suture materials sourced from natural sources include catgut, steel and silk. Synthetic plastic materials such as nylon, polypropylene and polymers of glycolic acid, lactic acid, etc., have become popular in recent decades.

Suture materials can also be classifed as absorbable and non-absorbable. Absorbable sutures hold the tissues together till they have healed suffciently to withstand normal stress, and are then absorbed by the tissues where they are embed-



ded. Non-absorbable sutures, on the other hand, are not absorbed, and they should be removed after the initial stabilisation of the wound edges has occurred. In reality, most or all natural materials will get absorbed by the body in due course of time. Thus, for clinical practice, a suture is considered non-absorbable if it retains its tensile strength in tissues for more than 60 days.

According to the flament type, the sutures may be monoflament or multiflament. A monoflament suture is essentially a single strand of fbre. This simple structure enables these sutures to pass through tissues with least resistance. Though this makes it the material of choice in delicate tissues such as the vascular tissues, there are some notable drawbacks. The handling and knot-tying are generally more taxing, and the knot has less friction to keep its position. In addition, the cut edges tend to be stiff leading to probable irritation of movable and delicate regions like the tongue and buccal mucosa.

The multiflament sutures are made of multiple fbre strands, which are either coated or braided together to make one fne thread. The process of braiding bestows a higher tensile strength as well as better pliability and fexibility. This improves the handling characteristics and the ease of knottying. They also better resist the tendency of the knot to untie itself. The cut edges are usually smooth and soft, and are not irritating to oral tissues. The disadvantages of multiflament sutures include the higher risk of harbouring pathogens in its structure and the tendency to 'wick' the oral fuids into deeper tissues through the suture track. This, in turn, can lead to occurrence to unaesthetic suture tracks visible on the skin.

#### **11.4.1 Suture Thread Size**

The suture thread is available in different thicknesses. The thickness is usually mentioned as 'number of zeroes'. This system follows the U.S. Pharmacopeia, and has gained wide acceptance. The most commonly used thread size for intraoral use is mentioned as 3–0 or 000 size. Sutures are available from size 6 to 11–0 (Table 11.2).

#### **Attributes of an Ideal Suture Material**


**Table 11.2** Suture sizes—U.S. Pharmacopeia designation and equivalent metric measurements


It is beyond the purview of this chapter to go into the details of all the types of suture materials available in the market, chemical structure, method of resorption, qualities, indications, advantages, etc. Details of few suture materials widely used in oral and maxillofacial surgery are given below.

#### **11.4.2 Natural Absorbable Sutures (Absorbed by Proteolysis)**

The absorbability characteristics of many natural materials had been recognised for millennia. All absorbable natural suture materials contain predominantly collagen. Over the years, they have progressively fallen out of favour due to the risk of antigenicity and adverse tissue reaction [1].

#### **11.4.2.1 Catgut**

Catgut has been the most popular material in this group. Its use has been prevalent at least from the time of Galen of Pergamon (200 AD). This material is made of tissue taken from the submucosal layer of sheep intestine or from the serosal (adventitial) layer of the cattle small intestine intima. The collagen strands are twisted together and the resultant thread is precision-ground to form a monoflament. Catgut has long been a popular fbre to make string instruments and tennis racquets. For many centuries, catgut (surgical gut) had been the only absorbable suture material available. The absorption is by proteolytic biodegradation brought about by proteolytic enzymes.

Performance-wise, catgut has good fexibility but relatively poor tensile strength, poor knot stability and high tissue reactivity. Full tensile strength remains only for 7 days.

#### **11.4.2.2 Chromic Catgut**

It has been found that many poor characteristics of catgut can be overcome by impregnating the suture material with chromic salts. This modifed product, called chromic catgut, has higher tensile strength and delayed absorption time. Chromic catgut retains its maximum tensile strength for about 2 weeks. It also has reduced tissue reaction as compared to plain gut.

Manufacturers package catgut sutures soaked in the disinfectant isopropyl alcohol solution to retain the fexibility and to increase shelf life. This necessitates rinsing of the suture in sterile saline to remove the irritant alcohol before use. Some manufacturers use a glycerine coating on chromic catgut to do away with the alcohol in packaging. Glycerinecoated chromic gut is smoother and thicker and has better handling characteristics.

#### **11.4.3 Natural Non-absorbable Sutures**

These are the oldest suture materials known to mankind. People tended to use any threaded material known to them for holding the wound edges together. Non-absorbable natural materials include cotton, linen, steel and silk.

#### **11.4.3.1 Cotton and Linen**

Cotton and linen sutures primarily contain cellulose polymer. Both the materials get absorbed in due course, but are considered non-absorbable because of delayed absorption time. Cotton is sourced from the hair of the cotton seed while linen is made from fax. The fbres are twisted to form a suture. It has good tensile strength, but there is moderate tissue reaction. Handling is average but knot-holding is good. Linen has the advantage that it gains tensile strength when wet.

Cotton and linen have largely fallen out of favour because of adverse tissue reactions and the high 'wicking' effect which causes seepage of fuids into the suture track.

#### **11.4.3.2 Silk**

Silk has been a well-known textile material from fourth millennium BC. It is produced by the silkworm larvae to form the cocoon. Natural silk is a protein fbre, the main components being fbroin and sericin. Fibroin forms the basic structure and contributes to the tensile strength. Sericin is a gum layer which holds the strands together. The silkworm larvae are cultivated and once they start pupating, the cocoons are dissolved in boiling water to extract the individual fbres which are fed into the spinning reel. To make it suitable as a medical product, the sericin protein component is later removed by a degumming process.

Silk is the most widely used natural non-absorbable suture material. Surgical silk is made from the larvae of the silkworm *Bombyx Mori*. The silk suture consists of a group of strands braided around a core and has a wax or silicon coating. It is usually dyed black in colour for better visibility.

The most impressive property of the silk suture is the ease of handling. It is extremely pliable and smooth and has good knot-holding capability. But the tensile strength is pretty low. The other drawbacks include high levels of tissue friction, capillary action and tissue infammatory response. The wax coating helps to counteract all these negative attributes.

Silk is now not considered an appropriate material for cutaneous suturing, except on specifc sites such as eyelids and lips. It is very often used for ligating blood vessels and for hitching drains. It is the most popular material used in dentistry. Its soft and pliable nature makes it suitable for use in oral mucosa which is mobile and wet.

#### **11.4.4 Synthetic Non-absorbable Sutures**

#### **11.4.4.1 Polyamide/Nylon (Ethilon, Dermalon)**

Nylon belongs to the frst generation of commercially successful synthetic thermoplastic polymers, having started production in 1927. It is made of repeated units linked by aliphatic or aromatic amide links (polyamide). It has been a very versatile material and has been used as fabric, fbres, flms, coatings and moulded shapes for wide applications in diverse felds.

Nylon surgical sutures were introduced in 1940. Monoflament nylon sutures are very popular for cutaneous suturing. The main advantages are their high tensile strength, exceptional elasticity and low tissue reaction. The elasticity helps the material to accommodate tissue swelling and maintain wound edge apposition. The nylon sutures are dyed black in colour.

The biggest shortcoming of this material is its shape memory, which negatively affects its knot-tying and knotholding properties. Often, one needs 3–4 knots to hold a stitch in place. Also, the monoflament may be stiff. Multiflament nylon sutures are available with increased pliability and handling features. Addition of fuid (alcohol) in the package reduces the shape memory and improves pliability.

#### **11.4.4.2 Polypropylene (Prolene, Surgipro)**

Polypropylene is another thermoplastic polymer used as a non-absorbable suture material. It is produced by chaingrowth polymerisation of the monomer propylene. It is pigmented blue to enhance visibility, hence the name polypropylene blue.

Similar to nylon, polypropylene has a very high tensile strength, excellent elasticity and minimal tissue reaction. It can extend up to 30% without breakage, making it highly suitable for suturing cutaneous wounds. The shape memory is also similar to nylon and can contribute to knot slippage. This feature, though, is advantageous in subcuticular suturing since it slides out smoothly during suture removal.

The excellent mechanical properties and inert nature have made polypropylene the material of choice in stressful sites. It is widely used in the management of hernia and vaginal prolapse, often in the form of a mesh in addition to sutures.

#### **11.4.4.3 Polyester (Ethibond, Surgidac, Dacron)**

Polyester is a general term used for any organic polymer which has an ester functional group in the main chain. More specifcally, the term is used for the material polyethylene terephthalate. It is a type of petroleum-based plastic, made by mixing ethylene glycol and terephthalic acid. Because of its durability, cleanability, anti-wrinkle and quick-drying characteristics, it swiftly made a name in the textile industry as a reliable material.

Polyester is a non-absorbable, braided, surgical suture with high tensile strength and low tissue reactivity. The braided nature adds to enhanced handling, knot-tying and retentivity. Thus, it combines the positive features generally attributed to monoflaments and multiflaments. It is thus the suture of choice in cardiovascular surgery, prosthetic implants and facelifts.

Polyester braided sutures are usually dyed green in colour. They may be coated or uncoated. The uncoated variant has a rough surface which produces drag in the tissues. The coating is made of PTFE or polybutylate.

#### **11.4.4.4 Polybutester (Novafl, Vascufl)**

Polybutester is a relatively new thermoplastic material with unique stress-strain properties. It is a copolymer comprised of polybutylene terephthalate and poly teramethylene ether glycol, and is coated with polytribolate. The polybutester monoflament sutures are designed to have high strength, elasticity and pliability. The fexibility and lack of memory allow it to be handled with ease resulting in a high knot security. The unique features have made this a popular material for abdominal wound closure.

The elasticity of polybutester is phenomenal. It can stretch 50% of its length at initial loads. It has a biphasic expansion curve wherein it expands well in response to initial stress and maintains pressure without cutting the tissue, and at the same time withstanding creep by not undergoing permanent deformation even under constant pressure.

#### **11.4.4.5 Polytetrafuroethylene (Gore-Tex, Cytoplast, Corefon, Tefon)**

Polytetrafuroethylene (PTFE) is a synthetic material which has found extensive application globally. It is a fuoropolymer of tetrafuoroethylene (-CF2-CF2-), made by free-radical polymerisation of monomer units. PTFE is a strong, tough, waxy, non-fammable material popular for its non-stick properties.

PTFE suture is considered as the ideal material for oral surgeries, especially for dental implant surgeries. It is inert, non-absorbable and monoflament in nature. The strong fuoro-carbon bond is thought to be the reason for its inertness. Unlike other synthetic monoflament sutures, PTFE is smooth, supple and soft. The cut ends cause no irritation to delicate oral tissues. It has no shape memory. It is well tolerated in the oral cavity and has excellent handling, knot-tying and knot-holding abilities. Thus, it has most of the positive attributes of braided sutures, at the same time avoiding the risk of bacterial contamination by wicking effect.

#### **11.4.4.6 Stainless Steel**

Surgical stainless steel non-absorbable surgical suture is composed of 316 L austenitic stainless steel. It can be monoflamentous or multiflamentous. The obvious advantages of stainless steel sutures are strength and low tissue reaction. Its drawbacks include very poor fexibility that makes it highly demanding in suturing skills. Incorrect technique can cause an excessive pull or tear on the tissues resulting in necrosis of wound edges. Barbs at the end can cause glove punctures and trauma to adjacent tissues.

Stainless steel suture is used in sternal closure and in orthopaedic procedures involving cartilage and tendon repair. It is also sparingly used for abdominal wound closure and hernia repair.

#### **11.4.5 Synthetic Absorbable Sutures (Absorbed by Hydrolysis)**

Till polyglycolic acid sutures were introduced in the 1970s, all absorbable sutures were natural. The synthetic absorbable sutures are all polymers based on glycolic acid, l-lactic acid, paradioxanone, trimethylene carbonate and e-caprolactone [2]. They are sterilised either by ethylene oxide gas or by gamma radiation. These polymers have defnite advantages over chromic catgut in clinical use. They are much stronger, evoke minimal tissue reaction, stay longer before absorption and leave no reactive changes after they are resorbed. They are absorbed typically by hydrolysis reaction which breaks the polymer chains. The hydrolysis end products are CO2, H2O and the monomer.

#### **11.4.5.1 Polyglycolic Acid (Dexon, PolySyn, PGA)**

Polyglycolic acid suture, introduced in the early 1970s, was the frst absorbable synthetic suture material. It is braided homopolymer of glycolic acid. The uncoated version is beige in colour while the polycaprolate-coated product may be undyed or dyed green, violet or bicoloured. When compared to catgut, the tensile strength and knot security are excellent. It retains 65% of its tensile strength after 2 weeks, by which time catgut would have lost all its strength.

The polylycolic acid soon became very popular but fell out of favour later as better products were developed in due course of time.

#### **11.4.5.2 Polyglactin 910 (Vicryl, Polysorb)**

Polyglactin 910 is a synthetic heteropolymer consisting of 90% glycolic acid and 10% lactic acid. Introduced in 1974, this is a multiflamentous, braided suture with a lubricant coating of polyglactin 370 (30:70 ratio) and calcium stearate. The fnal product is usually dyed violet in colour, but an undyed beige version is also available. Polyglactin 910 is among the most popular absorbable sutures used for surgical wound closure today.

The main advantages of polyglactin over polyglycolic acid include consistently higher residual tensile strength and faster absorption. The absorption happens between 40 and 70 days. The coating ensures smooth passage. Since the coating is made of similar material, the risk of faking is very low. Calcium stearate used in the coating is an absorbable organic lubricant. The shelf life of polyglactin is as high as 5 years.

As the material became very popular and widely used, manufacturers began to bring out modifed products providing specifc benefts. One of them is a monoflament version which does not require a coating. Another one is an 'antibacterial suture' with embedded triclosan, which is said to be very effective in preventing surgical site infections. Yet another useful modifcation is 'rapidly absorbing polyglactin' (Vicryl Rapide/Velosorb Fast). By treating the coating with γ-radiation, it is made to lose strength by second week and is fully absorbed by sixth week. This variant is widely used in oral surgery, where faster resorption is desired.

#### **11.4.5.3 Polydioxanone (PDS, PDO)**

Polydioxanone was the frst monoflament suture available of large size (larger than 3–0). It is a polyester product and is synthesised through the ring opening of the monomer paradioxanone (1, 4-dioxan 2-one). As a monoflament suture, it has much less drag through the tissues than polyglactin or polyglycolic acid. Since it retains its tensile strength over a long span of time (80% strength at 2 weeks and 60% after 6 weeks), it is considered a better alternative to polyglactin for suturing of fascia.

A modifcation called PDS II is chemically similar but is annealed above melting temperature to soften the external surface, imparting improved fexibility to the fnal product.

#### **11.4.5.4 Poliglecaprone 25 (Monocryl/Biosyn/ Petcryl Mono/Monoglyde)**

Often seen as the monoflament alternative to polyglactin, poliglecaprone is a segmented block polymer consisting of 75% glycolide and 25% ε-caprolactone. It is available as an undyed or a violet dyed version. The key feature that differentiates poliglecaprone from other monoflament sutures is the high level of pliability and handling properties. This is achieved through the formation of an interim soft polymer chain 'pre-polymer' which is high in caprolactone. In the ensuing stages of manufacturing, more glycolide is added to supplement hard segments to the pre-polymer. In this way, we get a fnal product with high tensile strength without compromising on the pliability.

The tensile strength of the undyed poliglecaprone suture degrades to 50% in 1 week and 30% in the second week. The dyed version retains 70% strength after 1 week. Complete absorption by hydrolysis happens in about 100 days.

#### **11.4.5.5 Polyglyconate (Maxon)**

This copolymer has a molar ratio of 64% glycolic acid and 36% trimethylene carbonate. It is an uncoated monoflament which may be undyed or dyed dark green. Polyglyconate has good handling properties. But its main advantage is the retention of tensile strength over a long time span. It retains at least 50% of its strength 4 weeks after implantation, making this an excellent choice in situations where long-term retention is needed. The slow absorption makes it relatively unsuitable for subcuticular sutures, since the dyed suture may be visible under the surface.

#### **11.4.5.6 Glycomer 631 (Biosyn)**

It is a synthetic absorbable coated monoflament polyester suture. It is a tri-block copolymer and contains glycolide (60%), trimethylene carbonate (26%) and p-dioxanone (14%). It may be undyed or dyed violet. It has high fexibility, low memory and minimal tissue reactivity.

It passes through the tissues easily but has poor knotholding capability. Degradation and absorption are similar to polyglactin. Full absorption is complete in around 100 days.

#### **11.4.5.7 Polyglytone 6211 (Caprosyn)**

Polyglytone 6211 is the only suture available with four different monomers in its core structure. It is a polyester copolymer of glycolide, caprolactone, trimethylene carbonate and lactide in the ratio 6:2:1:1. It is a monoflament, uncoated, absorbable suture which is undyed or dyed violet.

Polyglytone 6211 is a suture for the short-term approximation of tissues. Because of its quick disintegration, it offers an inert alternative to catgut that can evoke infammatory response. Its strength decreases to 50–60% at 5 days and to 20–30% at 10 days post-implantation.

#### **11.5 Knot-Tying**

The suture knot-tying can be accomplished by using an instrument (usually the needle holder) or using hands. Three main techniques are described.

#### **11.5.1 Two-Handed Tie**

The two-handed tie is cumbersome and is not routinely used. The suture is tied together by holding one tag in each hand and intertwining them.

#### **11.5.2 One-Handed Tie**

The one-handed tie is the most popular hand-tie method. It is quicker and can be accomplished in a smaller space. One end of the suture thread tag ('the long end') is held with thumb and forefnger of the dominant hand. The other side tag ('the short end') is placed a bit distal to the frst tag, running in the same direction. The middle fnger is folded and is used to guide the short end around the long end, and then the two tags are pulled away.

#### **11.5.3 Instrument Tie**

Instrument tie is the most popular technique for tying a suture knot. The long end is wrapped around the needle holder. Then the needle holder beaks are opened to grasp the short end, which is then pulled to form a tie. One such tie is called a 'throw'.

#### **11.6 Suture Knots**

The suture thread tags are intertwined to form a knot. The knot should be frm and tight, and should not lie on the wound/incision line. It is important that the knot stays tight and maintains strength during the healing phase. Knot slippage or breakage before healing can be detrimental to the wound. In general, knot security is higher for braided and uncoated sutures because of higher friction coeffcient.

The knots placed for the surgical suturing are of simple design. Those employed commonly are the square knot, surgeon's knot and granny's knot. These three variants are very similar to each other and differ from each other only in minor aspects.

#### **11.6.1 Square Knot/Reef Knot**

A square knot is among the simplest of the knot designs. It involves a simple intertwining of the two threads. This 'halfhitch' knot (one 'throw' around the instrument) need to be complemented with an additional similar throw to make it secure. Preferably the second hitch should be in the opposite direction, i.e. if the frst throw is in clockwise direction, the second one should be in anticlockwise orientation.

The classical square knot formed by a clockwise and a counterclockwise hitch can be further complimented by more similar hitches in alternatively changing directions.

#### **11.6.2 Surgeon's Knot**

A surgeon's knot is a minor modifcation of the square knot in which the initial intertwining is doubled. This is accomplished by doubling the frst throw, by doing two turns of the thread around the instrument. This is followed by a regular second throw in the opposite direction.

#### **11.6.3 Granny's Knot**

In the granny's knot, two initial throws are placed in the same direction, followed by a third throw in the opposite direction.

#### **Principles of Wound Suturing**

Regardless of the specifc technique, some basic principles are to be followed while performing a suturing procedure. It is to be remembered that these are only general principles, and can be modifed or rejected in specifc situations depending on the clinical context.


#### **11.7 Specifc Suturing techniques** [3] (Video 11.1)

There are quite a large number of techniques available to stitch a wound. Only the commonly used methods are mentioned.

#### **Factors to Be Considered on Specifc Material and Technique**


#### **11.7.1 Simple Interrupted Suture**

A simple interrupted suture ('simple loop') is the most common method to suture a wound. This is the simplest design of wound closure. The suture passes once through each side of the wound in a simple loop and is then tied in a knot above the surface. Multiple such ties are made over the length of the wound, resulting in several independent sutures collectively securing the tissue edges together. The same technique is frequently employed for internal suturing of tissue layers also [4].

The needle penetrates the surface 2–3 mms away from the wound edge on one side and proceeds into the subcutaneous tissue. The curve of the needle is then used to pass it through to the subcutaneous tissue on the opposite side. The needle then exits through the surface. The initial and fnal tags, now outside of the tissues, are then tied in a knot. The confguration inside the tissue is thus in the form of a loop. If the wound sides are of unequal depth, then the needle should travel deeper in the lower side while staying superfcial on the higher side. This will help to correct the depth disparity and ensure proper surface levelling.

This technique is easy to learn and employ. This suture provides good tensile strength and carries minimal risk of wound oedema or impaired circulation. Several adjustments to the design are possible with this method depending on the wound characteristics. Since there is a series of multiple sutures, even if one suture fails, the others may provide suffcient strength to keep the wound edges together (Fig. 11.4).

The major drawback of this method of suturing is the high possibility of 'rail-road track' shaped scars caused due to the ingrowth of epithelium into the suture tracks. There is also a tendency to cause 'wound inversion' (depression of the surface at the wound site) due to tissue contracture during healing. The inversion can be prevented by making the suture confguration 'fask-shaped' inside the tissues, by making the needle travel farther laterally away from the wound within the tissues. When compared to continuous suturing techniques, the interrupted method is more time-consuming as it requires many more knots need to be tied.

R. Veeraraghavan

#### **11.7.2 Simple Buried Suture**

The buried suture is a modifcation of the simple interrupted suture and is reserved for stitching the inner (deeper) tissue layers. The only difference is that the knot ends up in the tissues deeper to the suture loop, i.e. away from the surface. In essence, this is a simple interrupted suture in the reverse orientation.

The wound edge is frst refected using fne forceps or hooks. The needle is then inserted into the underside of the dermis on one side. The needle then proceeds along its curvature to exit in the wound edge more superfcial to the initial bite. The needle then pierces the dermis wound edge (near the surface) on the opposite side, proceeds in a path mirroring its motion in the frst side and comes out at a deeper point which corresponds to the frst bite. Though the tie is done outside, the knot gets buried deep inside the tissues as it is tightened (Fig. 11.5).

This technique is extremely useful in suturing the inner tissue layers before the surface closure. As the knot is buried deep, it does not interfere with the closure of superfcial layers. This aspect is extremely useful while closing cutaneous facial wounds.

Two major drawbacks have been observed with this suture. One is a skin dimpling which typically happens if the suture arc inadvertently involves the epidermis. Another problem is the tendency for wound inversion to occur. Small modifcations such a set-back dermal buried suture or a vertical mattress buried suture can be employed to overcome this

**Fig. 11.4** Simple interrupted suture technique

#### **Fig. 11.5** Buried suture

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

problem. These modifcations attempt to pass the bridging suture segments to be deeper, thus resulting in wound eversion.

#### **11.7.3 Vertical Mattress Suture**

The vertical mattress suture is in part similar to simple interrupted sutures but includes an additional suture bridge close to the wound edge. Also known as Donati Suture, or 'far-far, near-near' suture, this is the most frequently used suturing technique to obtain wound eversion [5]. This suture design is very popular in abdominal and limb surgeries.

The needle is frst penetrated far from the wound edge (about 6 mm), and then proceeds through the deeper tissue to the opposite side and emerges out at an equal distance from the edge. The needle is then reinserted at a point closer (2–3 mm) to the wound edge on the second side itself. It is then rotated superfcially through the tissues and is exited on the other side at a corresponding near point. This results in a double bridging of the wound, one deep in the tissues and another superfcial and nearer to the wound edge. Thus, both tags of the thread are now on one side of the wound. They are tied together gently (Fig. 11.6).

The primary advantage of this suture is the resultant wound eversion. This eversion is expected to compensate for the anticipated contracture occurring along the wound margin. As the suture is bridging the wound twice, the binding strength is more. Elimination of dead space is another obvious advantage. The suture thread does not pass the wound edge on the surface, minimising the chance of track marks.

On the fip side, fne wound edge approximation is almost never achieved with this suture. Excessive tightening could lead to over-constriction and sometimes exposure of the raw area. This may necessitate placement of additional interrupted sutures for better results.

The vertical mattress concept can be used in a buried suture situation also by ensuring that the more superfcial suture thread passed back to the frst side in a path parallel to the frst, deeper suture bridge. This will result in a better wound eversion.

#### **11.7.4 Simple Continuous Suture**

Simple continuous suture ('running loop', 'standard running suture') is a good method for rapid closure of small wounds. It gives an even distribution of tension all along the wound span. It combines many benefts of the simple interrupted sutures with the additional advantage of a quicker fnish.

The technique is very simple. The frst part follows the same process as a simple interrupted suture. The frst knot becomes the anchoring knot for the ensuing running line. The tags are not cut and the longer tag (with the needle) is used for making the remaining loops. The needle is inserted back into the tissues a few millimetres away from the frst piercing. Then the needle (followed by the thread) passes through the tissues in a path parallel to the frst loop. Once it comes out of the second loop, it is not tied. Instead, the loop is tightened and the thread crosses over obliquely across the wound and enters the tissue surface again, a few millimetres away from the second piercing. This process continues over and over until one reaches the other end of the wound. As the last loop goes through the tissues, the thread is only partially pulled through, leaving some loose thread on the opposite side. The suture is then tied to this loose thread for the fnal knot. Thus, the suture material runs across the wound in repetitive loops, and there are only two knots—one at either end (Fig. 11.7).

The obvious advantages of this technique are the quickness of suture placement and the ease of avoiding many knots. Also, if the tissue wells up in one site, the remaining part of the suture can provide some compensatory slack.

The principal drawback is that the integrity of the entire suture line is vested in just two knots. Any breakage to the suture at any point leads to the entire line getting untied. Since the loops are in continuous succession, fne-tuning of design for each loop is not possible. Also, since the tension is the same across all loops, the areas of the wound with greater tension, usually the central part, may tend to gape.

#### **11.7.5 Locking Continuous Suture**

This is a variation of the simple continuous suture technique used for surface wounds. Each loop of the continuous suture is 'locked' on itself before making the next loop. This is the most popular continuous suturing technique especially for closing wounds over long spans. As with other superfcial continuous sutures, this method is frequently used as a surface layer after the internal tissue layers have been closed.

Similar to the simple continuous technique, the frst loop is passed and the knot tied. After the second loop has gone through the tissues and exited, the suture is not immediately tightened. The needle and the leading thread it is made to pass through the earlier loop. After making this 'lock', the suture is tightened and is then passed into the tissues for the third loop. The assistant should maintain this tension until the next loop is passed. This process is repeated for the entire line of succeeding loops (Fig. 11.8).

The locking helps to align the tissues in a proper anatomic orientation perpendicular to the wound. There is an added haemostatic effect due to the tension on tissues. Uniform degree of tension is maintained across all the loops. At the same time, the running locks partially detach the tension on the individual loops from one another. Thus, to an extent, individual control of tension depending on the site can be obtained.

This technique inherits the main disadvantage of the simple continuous sutures of being dependent on only two knots, and the risk of complete loss of suture integrity in case of breakage at any point. The locks, if they are too tight, may cause vascular compromise of underlying tissues.

**Fig. 11.7** Simple continuous suture

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

#### **Fig. 11.9** Subcuticular suture

#### **11.7.6 Subcuticular Suture**

This is a mostly buried, continuous, epidermal wound closure which is used for surface closure. The suture ends exit a few mms away from the wound corner. The subcuticular suture is employed only after the deeper structures and dermis have been secured well with absorbable sutures. It is popular as an aesthetic suture for face [6].

The suture may be absorbable or non-absorbable, and is usually thin (size 5–0 or 6–0). The needle insertion is at one end of the wound, 2–5 mm away from the apex. It is passed along the curve into the wound, where it exits in the interior, close to the apex. Then the needle is inserted again into the dermis on any one side of the wound edge walls. Thereafter, it passes horizontally parallel to the surface, and following the needle curve to come out into the wound interior a small distance away. The same step is then repeated on the other side of the wound. This process is repeated till one reaches the other end of the wound, wherein the needle is made to pierce the far end apex and to come out in the surface. This last step is a mirror image of the initial steps. Then each of the suture tags on both sides is tied separately on to itself. Alternatively, the tags may be secured with adhesive strips, surgical tape or tissue glue (Figs. 11.9 and 11.10).

The biggest advantage of this technique is the much decreased risk of scars. The close approximation achieved in the dermis region makes the need for a further surface suturing unnecessary. The tension is aligned centrally across the wound and is evenly distributed all along the length of the suture. Also, this technique is highly suitable in cases where the suture material is required to stay in place for a long period of time.

On the negative side, the subcuticular suture takes longer time to perform. Leaving a large quantity of foreign material in situ can increase the risk of foreign body reaction and infection. If non-absorbable material is used, there is a minor risk of long and thin suture track following removal. If absorbable material is used, an undyed suture should be chosen to prevent cutaneous visibility. Incorrect technique can leave small segments of exposed raw area, which need to be addressed with additional surface sutures.

#### **11.7.7 Purse-String Suture**

This is essentially a modifcation of the simple continuous suture, and is designed to reduce the size of a two-dimensional surface defect. It is not a cosmetically superior technique and is rarely used in the face. The purse-string effect causes a puckering in the surrounding skin tissue. But this is an effective method to reduce wound area. It may also be used to achieve haemostasis.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 11.10** Subcuticular suture at the subciliary incision site and at the pre-existing lateral orbital laceration in a case of zygomatic complex fracture fxation

**Fig. 11.11** Three-point suture technique

At frst, the wound edges of the defect need to be freshened and underlined. The needle and thread is passed along the edge of the defect in a course running parallel to the wound edge. Thereafter, it continues in a series of loops running along the edge of the surface wound along its entire circumference. As the thread completes the full distance and reaches near the initial needle entry, it is pulled taut, leading to complete or partial closure of the wound. Then the tags are tied together.

#### **11.7.8 Three-Point Suture**

Also known as 'tip stitch' or 'half-buried horizontal mattress suture', this technique is used for managing a situation where three ends of the tissue have to be sutured together. In maxillofacial surgery, this situation is encountered while repairing V-shaped lacerations and while closing faps with sharp corners (such as the triangular fap at the vermilion border for cleft lip repair)

This suture is placed only after the faps are brought into position using buried dermal sutures. The surface suture thread is used, that is, 6–0 for face and 3–0 for scalp. The needle is frst inserted into one side of the non-fap side of the wound. It follows the needle curve to exit in the inner aspect of the wound. The next tissue insertion is into the superfcial dermis of the fap tip. Then the needle passes horizontally and comes out through the dermis on the other side of the fap tip. After releasing from the fap tip, it re-enters the dermis of the non-fap side on the other side and comes out through the skin at a point corresponding to the initial entry. The tags are then knotted together (Figs. 11.11 and 11.12).

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 11.12** A laceration that needs three-point suturing

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 11.13** Frost suture

#### **11.7.9 Frost Suture**

The Frost suture is a temporary eyelid suspension suture, used to ensure proper lower eyelid placement during the post-operative period [7].

After the closure of the lower eyelid incision, a needle bite is taken on the tarsal plate or just inferior to it. Then a second bite is taken just above the eyebrow, ensuring the anatomic position and alignment of the lower lid. These tags are then tied or secured with tapes or tissue glue (Fig. 11.13).

These sutures may be removed on third post-operative day, but need to be kept longer if there has been signifcant trauma to the tissues.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 11.14** Drain anchoring suture

#### **11.7.10 Drain Anchoring Suture**

Different types of drains are used in surgery, such as corrugated rubber drain, the suction drain, intercostal drain, etc. After the drain has been inserted, it needs to be securely fxed to the body to prevent displacement.

The most common means to secure drains is the Roman Garter method, which uses silk sutures. A strong bite is frst taken on the skin near the drain entry site. After making a knot, the two suture tags go around the drain tube in a series of windings. A knot may be tied after each 2 or 3 turns around the tube. The large number of windings around the tube increases the friction, holding the tube in position without dislodgement (Fig. 11.14).

Other techniques which have been described include the use of nylon suture, safety pin, drain clip, adhesives and Tie-lok.

#### **11.8 Dentoalveolar Suturing**

The tissues and the surgical environment in the dentoalveolar region are different from other parts of the body. Consequently, the wound closure requirements also differ. Wound closure in dentoalveolar surgery involves suturing in situations such as


In most cases, the needle passage is through keratinised mucosa with little or no subcutaneous tissue, obviating the need for multilayered closure. The presence of teeth or artifcial crown on one side of the fap forces the surgeon to innovate on the basic suture design. Another difference is when the extraction wound is closed—the wound is usually closed only at the edges and is largely left open in the middle. Also, the suture site will have to endure itself in a challenging environment with the presence of saliva, food materials and a very dynamic milieu where tongue movements and masticatory forces abound [8].

If marginal gingiva is not involved in the fap (as in a semilunar fap), the wound closure models are usually not different from the general cutaneous designs which were discussed in the previous section.

#### **11.8.1 Simple Interrupted Suture (Interdental Suture)**

As in any case of wound closure, the simple interrupted suture is the mainstay in closing dentoalveolar faps [9]. In general, it involves suturing the detached interdental papillae together. The needle passes from the buccal aspect of the buccal fap, emerges on the inside of the fap and then passes between the tooth roots to enter the inner aspect of the lingual fap. As it pierces the lingual fap and emerges through the mucosa, the needle is turned back and is taken back via the interdental region to the buccal side. The two suture tags are then tied together. Thus, the knot remains on the buccal side and is accessible for removal.

If only one fap (usually buccal) has been raised, the needle can still pass through the attached lingual fap and the suture design stays the same. In post-extraction wounds also, the procedure is the same, and the tooth socket space is not totally closed.

#### **11.8.2 Interrupted Reversing Suture**

In this modifed interrupted suture, the direction of the needle is reversed for engaging the lingual papilla. Once it passes through the buccal papilla and reaches the lingual side, the needle orientation is reversed and it is made to enter the lingual papilla from outside (lingual side). The needle exits the fap on the inside, passed across to the buccal side and is then tied. Thus, both the papillae are engaged in an 'outside-to-inside' orientation, ending in a fgure-of-eight formation in the vertical plane (Fig. 11.15).

This technique is especially useful in cases where both buccal and lingual faps are raised during surgery, such as in periodontal surgeries.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 11.15** Interrupted reversing interdental suture

#### **11.8.3 Vertical Mattress Suture**

Vertical mattress technique in dentoalveolar surgery is a modifcation of the papilla-attaching simple interrupted technique. After the initial passage of the needle through the buccal and lingual papillae, the needle is turned back and picks a small bite at the tip of the lingual papilla before passing back to the buccal side. Then it again pierces the tip of buccal papilla before knot-tying.

While this technique helps in pressing the papilla into the interdental space, it is not a popular technique because of the diffculty in getting a solid bite at the papilla tip without 'cutting through'. Obviously, one needs to use an atraumatic needle with a small thread (4–0 or smaller) for this purpose.

#### **11.8.4 Horizontal Mattress Suture**

This is a two-dimensional suturing technique where the suture thread is spread in a horizontal fashion in the tissues. It is not very popular for general cutaneous suturing but is especially useful in dentoalveolar surgery.

When closing faps in edentulous areas, the needle frst passes through both faps. Then it is reinserted into the fap on the same side, a little distance away from the earlier exit point. The reinserted needle now passes through both faps and emerges out a similar distance away from the initial entry point. Both the thread tags, now on the same side, are tied together (Fig. 11.16).

In dentulous areas, this technique sutures two adjacent papillae together, eventually tying four papillae segments around a tooth in a horizontal square fashion. To close extraction wounds, only the papillae are approximated and the tooth socket space is not closed completely.

The advantage of this technique is that a single horizontal mattress suture serves like two separate interrupted sutures, thus helping to reduce the number of sutures. It compresses the wound from four corners and helps in haemostasis. It also results in some degree of wound eversion.

#### **11.8.5 Horizontal Mattress Modifcation: Dental Anchor Suture**

In this modifcation, the suture does not pass through the lingual soft tissues. After passing through the buccal papilla, the suture passes through the interdental region into the lingual side. Without engaging the lingual papilla, it goes around the tooth and comes back to the buccal side via the interdental space on the other side. Then it engages the buccal papilla before being tied. In this way, it secures the papilla to the bone using the tooth as its 'anchor'.

This technique can also be used in a reversing fashion, where only the papilla on the lingual side is engaged and the buccal side papillae are not pierced.

#### **11.8.6 Horizontal Mattress Modifcation: Mattress Sling Suture**

This technique attempts to combine the benefts of vertical mattress suture with those of horizontal mattress suture. The basic technique goes similar to the horizontal mattress but the fnal tag re-enters the buccal papilla at the tip and traverses a reverse path around the tooth to exit near the initial entry. In this way, it ensures the engagement of both buccal papillae in a vertical mattress fashion.

#### **11.8.7 Horizontal Mattress Modifcation: Figure-of-Eight Suture (Cruciate Mattress Suture/Cross Suture)**

The fgure-of-eight suture is the most popular modifcation of the horizontal mattress technique. This is used mostly in closure of extraction wounds, and never in the presence of teeth at the wound site.

The needle frst penetrates the buccal papilla on one side and then the lingual papilla. Then the thread crosses across the edentulous site, and the needle is reversed in orientation to pierce the buccal papilla of the other side from outside

**Fig. 11.16** Horizontal mattress suture (extraction wound)

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

(buccal side) to pass through the lingual papilla and exit on lingual side. Then the thread passes across the site to be tied with the initial tag. The suture thus ends with the appearance of suture material crossing the wound site in a 'cross' shape (Fig. 11.17).

Many surgeons consider the fgure-of-eight suture to be the most comprehensive way to suture a single tooth extraction site. This method ensures an even tension on the tissues from four corners, effectively constricting the wound. There is a positive effect on haemostasis also, due to the tension on the fap and due to its presence a mechanical barrier to clot loss.

#### **11.8.8 Simple Continuous Suture**

The continuous sutures are almost exclusively used for edentulous situations including post-extraction closure. After making a conventional interrupted suture knot, the longer tag is not cut and is instead used to make a series of 'running loops' approximating the succeeding pair of papillae one after the other. Gentle tension must be maintained on the thread to keep the loops tight while the needle passes through the next tissue. Knots are not tied for each loop but is done only at the other end of the long wound. Some surgeons prefer to tie a knot after 3 or 4 running loops. In the end, the part of the suture passing through the inner tissues are perpendicular to the wound, and the superfcial, exposed parts lie across the wound in an oblique fashion.

The continuous sutures save time and effort while closing wounds of long span. It also ensures an even distribution of tension across the wound. The obvious disadvantage is the fact that if one loop or part of the suture is compromised (by

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 11.18** Continuous locking suture (dentoalveolar)

untying, cutting through or loosening), the entire suture line gets loosened.

#### **11.8.9 Continuous Locking Suture**

The continuous locking suture is a continuous suture in which a 'lock' is incorporated by passing the thread under the previous loop before it is pulled through the tissue. It is important to keep maintaining the tension on the previous loops as the needle makes the next pass through the tissue (Fig. 11.18).

This technique ensures a better orientation of the sutures with respect to the wound. The superfcial, exposed parts of the suture are oriented perpendicular to the wound, leading to better anatomic wound approximation.

#### **11.9 Suture Removal**

Non-absorbable sutures on skin and mucosa should be removed after the wound surface has achieved initial stability. The timing of suture removal is very important. They should remain in tissue long enough to prevent dehiscence and scar spread. On the other hand, early removal reduces tissue reaction and suture marks.

Sutures on facial skin and in oral cavity are usually removed in 5–7 days. The recommended interval is 3–5 days for eyelids, 7 days for neck and 7–10 days for scalp. Those on trunk and limbs should remain in place for 10–14 days.

The suture line is cleansed with antiseptic. The knot is grasped and is pulled away mildly from the surface and to one side of the wound. An uncontaminated segment of the thread is exposed on the other side by this pull. The thread is cut at this segment near to the surface. Then the suture is pulled out, making sure that no contaminated (exposed) part is ragged through the tissues.

In the case of a continuous suture, every single loop should be cut and pulled out separately. A subcuticular suture is removed by cutting the knot off at any one end, and then pulling the suture out gently from the other end. It is important to make sure that the suture does not break within the tissues.

#### **11.10 Other Wound Closure Methods**

#### **11.10.1 Staples**

The use of specialised staples for wound closure was popularized in 1900s by the Hungarian surgeon Hümér Hültl, known as the 'father of surgical stapling'. Compared to suturing, surgical stapling is a quicker method to close the skin in large wounds, and the infammatory response is relatively less. Staples provide good wound edge eversion without strangulation of the tissue. It is an excellent method to employ in cases which require quick wound closure and where aesthesis is not a major concern [10] (Fig. 11.19).

Though titanium staples were initially used, almost all of the contemporary hardware is stainless steel. However, titanium retains the advantages of being biocompatible and MRI-compatible. Bioresorbable staples, based on polyglycolic acid, are also available. The stapler devise itself may be of stainless steel (reusable) or plastic (disposable), into which the disposable staple cartridges can be loaded.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 11.19** Stapled scalp incision in a coronal approach

In maxillofacial surgery, staples are frequently used to close scalp wounds and neck incisions, following the closure of internal layers with conventional sutures. Staples are also popular in reconstructive surgery to secure skin grafts and to close the fap donor sites. They are not generally used to close facial wounds, since there is a tendency to produce 'rail-road track' scars. Skin staples are removed after 7-10 days with a specialized staple remover device.

#### **11.10.2 Tapes**

Different types of surgical adhesive tapes are used to effect wound closure, to reduce tension on sutured wounds and to reinforce wound site after suture removal.

The indications of this method for wound closure per se are limited. Tapes can be used to close superfcial lacerations where tissue tension is minimal. They are also employed in the closure of superfcial layer after buried dermal sutures have been employed for wound edge approximation and tension reduction. A major indication is its use an additional reinforcement and protection over sutured wounds. The advantages of using tapes for wound closure are.


On the other hand, there are signifcant limitations to the use of tapes to close wounds. The most obvious contraindication is an area under signifcant tension. Tapes are diffcult to apply on to highly convex surfaces, irregular wounds and in areas of tissue laxity. They do not attach well to wet surfaces (e.g. oral mucosa). They may get detached easily in hairy areas and those which tend to sweat.

These tapes are typically made of synthetic reinforced material with a hypoallergenic adhesive and are made porous to make them 'breathable' for skin. Some products are made elastic to account for oedema tension while some have incorporated antibiotic to reduce the incidence of surgical site infection. Modifcations of tape-based wound closure include incorporation of a zip-lock mechanism and a clip attachment, both techniques designed to pull the wound edges together for better approximation.

#### **11.10.3 Adhesives**

The use of tissue adhesives is an effcient way to close wounds in select cases. Just like surgical tapes, tissue adhesives can be used to approximate wounds that do not require deep-layer closure and do not have signifcant tension on the edges [11].

All currently available tissue adhesives are chemically cyanoacrylates (esters of cyanoacrylic acid). These compounds were discovered by Ardis in 1949 and were frst used in surgery by Coover in 1959. These are chemically similar to methacrylates, the only difference being the methyl (CH3) group substituted with cyano/nitrile (CN) group. The water present on the skin or mucosal surface activates the acryl groups in the resin to rapidly polymerise and form long, strong chains. Three types of tissue adhesives are currently available for clinical use—2-octyl cyanoacrylate, N-butyl-2-cyanoacrylate and isoamyl 2-cyanoacrylate. The adhesion involves two mechanisms—mechanical interlocking into the surface irregularities and chemical covalent bonding with the nucleophilic amine groups on skin surfaces.

Tissue adhesives are mainly used to treat superfcial skin tears (that do not extend past the dermis) and for surface closure after the deeper layers are secured with sutures. Other indications include stabilisation of bone fragments during plating, sealing of CSF leaks and sinus perforations, attaching grafts, achieving peripheral nerve reanastomosis and closure of dentoalveolar faps [12]. They are also widely used to achieve haemostasis at surgical sites and as a biologic cover on ulcers. The relative contraindications include wounds over or near joints and wounds under signifcant static or dynamic skin tension. Also animal bite wounds, crushed wounds and wounds in high friction areas and those with cross mucocutaneous borders are not considered suitable for a closure using adhesives.

The procedure for using the tissue adhesives for surface closure involves thorough cleaning and haemostasis. Though moisture is a prerequisite for adhesion, the presence of excessive water or blood at the site is detrimental to a good result. The surface is dried before applying the adhesive in at least three to four thin layers along the length of the wound's surface. It is advisable to extend it approximately 5–10 mm from each side of the wound. The edges of the wound are held together for at least 1 minute as the adhesive dries.

The main advantages of tissue adhesives over other wound closure methods are the rapidity and painless application [13]. In addition, the suture track scars are avoided, leading to a much better cosmetic result. The risk of suture site infection is also found to be less. The material sloughs off in 5–10 days, as the skin sheds.

The obvious disadvantage is that it cannot be used in areas of tension. Additionally, there is a minor risk of toxicity and foreign body reactions. If the clinician's gloved fngers, gauze or plastic instruments contact the tissue adhesive during application, these materials may adhere to the patient's skin.

#### **11.11 Conclusion**

Wound care primarily involves measures to ensure that the wound heals quickly without going through adverse situations such as infections. Along with mechanical debridement, antibiotic medication and dressings, the various wound closure methods form the foundation of wound care practices. Depending on the patient needs and the wound types, one should choose from a wide variety of materials and techniques to implement effective wound closure.

#### **References**


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## **Postoperative Care of the Maxillofacial Surgery Patient**

J. Naveen Kumar and Poornima Ravi

Postoperative care of the patient encompasses the time from the completion of the surgical procedure to the complete return of the patient to the normal physiological state. This is divided into three phases. Phase I is early recovery and takes place in the postanesthesia care unit (PACU). Phase II is intermediate recovery, and takes place in the ward. Phase III is late recovery that occurs after discharge.

### **12.1 Assessment of the Patient After Surgery**

#### **12.1.1 Assessment of the Patient Immediately After Surgery**

Postoperative care of the patient begins immediately after the surgical procedure has been completed, even before the anesthesia is reversed. The frst step is clearing the airway of blood and debris. Maxillomandibular fxation and occlusal splints, if placed earlier need to removed [1]. The next step is the removal of the throat pack.

#### **12.1.1.1 Care of the Airway**

The decision to extubate or not must be made in conjunction with the anesthetist. Cases in which there is a high risk of airway edema will require the ET tube to be retained [1]. These include:

J. N. Kumar (\*)

P. Ravi


In other cases, the patient may be extubated on the table. Awake extubation is usually preferred for head and neck surgery. The patient may be extubated when the following criteria are met [1]:


Once the extubation is done, an oropharyngeal airway can be inserted to prevent clenching of teeth and the tongue from falling back, which can cause obstruction. Alternatively, a nasopharyngeal airway can be used in case the surgeon deems oral cavity unft for manipulation using the former. This must remain in place until the patient is conscious and obeys commands.

Some patients, such as those who have undergone extensive face and neck resection, may have required a tracheostomy prior to surgery. The tube must be secured after surgery by taping the stay sutures to the neck or chest. Tracheostomy care in the postoperative period is critical; a blocked or dislodged tube can have disastrous consequences [2].


Oral and Maxillofacial Surgery, Sri Ramachandra Institute of Higher Education and Research, Chennai, India e-mail: naveenkumarj@sriramachandra.edu.in

Department of Oral and Maxillofacial Surgery, SRM Dental College, Ramapuram, Chennai, Tamil Nadu, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 239

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_12


#### **12.1.1.2 Need for Ventilation in the PACU**

In some instances, ventilation may be required even after anesthetic recovery. Some examples include:


While monitoring the patient who is on a ventilator, it is important to be aware of the various modes that the ventilator operates on [3]. These have been summarized in Table 12.1. Patients who have been on the ventilator for long periods of time need to be weaned off slowly. OMF surgeons frequently come across such patients in neurosurgical ward having concomitant traumatic brain injuries and craniomaxillofacial fractures. This may be done by setting the ventilator in CPAP mode (Continuous Positive Airway Pressure). This allows the patient to breathe, with the ventilator taking over if the patient is unable to do so.

#### **12.1.1.3 Monitoring in the PACU**

Once the patient has been shifted to the recovery room, the cardiac monitor and pulse oximeter must be attached for


**Table 12.1** Ventilator modes and settings

proper monitoring. The following parameters must be monitored continuously:


The suction apparatus must be kept handy to evacuate blood ooze or secretions that may hamper the airway. It is advisable to avoid Maxillomandibular fxation (MMF) in the immediate postoperative period; if required, this may be done after 24 h.

Detailed surgical notes must also be recorded, along with the number and type of implants that were used. Postoperative instructions must also be documented in detail. A list of notes to be completed by the surgeon before leaving the operation theater complex is summarized in Table 12.2.

#### **12.1.1.4 Briefng the Patient and Family**

Immediately after the surgery, the surgeon must interact with the patient's immediate caregivers, giving them the details of the procedure, and any anticipated complications.

#### **12.1.1.5 Discharge from PACU to Ward**

This is done when the patient has regained consciousness, with adequate respiratory function and stable vitals. Decisions can be made based on a standard scoring system, such as the Aldrete scoring system [5]. The scoring system which was originally proposed in 1970, underwent modifcations in 1995 and 1999. The various factors considered

**Table 12.2** Checklist for completion before leaving the theater complex

Checklist to complete before leaving the OT Surgical notes Details of implants and hardware used Postoperative instructions to be followed by nursing staff Postoperative fuid management instructions Postoperative medication dose and schedule Biopsy requisition form Requisition form for aspirates/swabs and others Investigation requisition form


**Table 12.3** Subjective assessment of the patient

are patient activity, respiration, circulation, consciousness, O2 saturation, pain, surgical site bleeding, and nausea/vomiting. Patients scoring greater than 9 on this scale can be moved to the ward for the next phase of care. Readers are advised to refer the article for getting a detailed idea of the scoring table.

#### **12.1.2 Comprehensive Assessment of the Patient in the Ward**

This is done according to the SOAP format [6]. SOAP is an acronym for Subjective, Objective, Assessment, and Plan. In Subjective evaluation, the patient must be asked if they have any complaints. Specifc complaints are recorded. In Objective evaluation, a thorough evaluation of the patient is done by the physician. This includes evaluation of the vital signs, fuid intake and output, as well as an assessment of the surgical site. Helpful information may be obtained from the TPR chart, input/output chart, and nurses' notes. Based on the subjective and objective evaluation, the patient's current status is assessed (Tables 12.3 and 12.4). This is used to formulate a plan.

#### **12.1.2.1 Postoperative Investigations**

Sometimes investigations may be required in the postoperative period, either to check the health status of the patient or to confrm the diagnosis of certain complications. A list of investigations that may be ordered and the indications for the same are summarized in Table 12.5.

#### **Table 12.4** Objective assessment of patient


**Table 12.5** Postoperative investigations


#### **12.2 Formulating a Plan of Care Based on Assessment**

#### **12.2.1 Fluid Therapy in the Postoperative Period**

The patient is usually 'nil per mouth' for a few hours prior to surgery and after surgery. Apart from this, there is a loss of blood and body fuids in any surgery, which requires replacement. It is therefore essential to infuse intravenous fuids during this period [7, 8]. This is done for two purposes.

**Replacement** Any fuid defcit that has occurred must be replaced by infusion. This could have occurred during either of the following periods:

	- NPO status.
	- Blood or fuid losses that may have occurred due to trauma, burns, etc.

**Maintenance** This is to maintain the ongoing fuid requirements, till the patient resumes oral intake of fuids. Maintenance fuids are essential to maintain proper pH and electrolyte balance and for adequate organ perfusion.

#### **12.2.1.1 Types of Fluids Used**

There are three types of fuids than can be used—crystalloids, colloids, blood and blood products. The preference of one type of fuid over another has several controversies, and there are no clear-cut guidelines available [9]. A few indications for each fuid type are given below.

#### **Crystalloids**

Crystalloids are balanced salt solutions with or without the addition of a buffering agent. When infused into the bloodstream, crystalloids tend to leave the capillaries and enter the extravascular fuid compartment. Crystalloid infusion will increase fuid in the extravascular tissues and does little to expand the circulating blood volume. In maxillofacial surgery, crystalloids are favored as maintenance fuids during the postoperative period.

#### **Colloids**

Colloids are protein-containing solutions. Since these proteins have a large molecular size, under ordinary circumstances, these are prevented from crossing the capillary endothelial cells and going into the extravascular space. Therefore, they tend to expand vascular volume alone. Colloids are mostly used in the intraoperative period if there has been signifcant blood loss and the plasma volume needs to be expanded. It is not common to use colloids in the postoperative setting.

Commonly used iv fuids are listed in Table 12.6.


**Table 12.6** Commonly used postoperative IV fuids

#### **12.2.1.2 Strategy for Estimating Fluid Requirement**


This is done using Holliday and Segar's formula (The 4-2-1 rule) [10].


E.g. a 60 kg adult will require (4 × 10) + (2 × 10) + (1 × 40) = 40 + 20 + 40 = 100 ml/h.

3. Calculate the total Estimated Fluid Defcit: This depends on the number of hours from the last oral intake to the next oral intake. For example, if the patient has not had oral intake for 12 h:

EFD = EFR × no. of NPO hours = 100 × 12 = 1200 ml.


Total postsurgical fuid requirement: 1200+ (300 × 3)−1000 = 1200 + 900−1000 = 1100 ml.

#### **12.2.1.3 Liberal Versus Restrictive Fluid Therapy**

In recent years, the above method of estimating fuid requirements has been criticized, as it tends to overestimate the amount of fuids needed by a patient [11]. Excessive fuid infusion may cause fuid shift into the extravascular compartment, which in turn can result in overload complications such as renal injury, acute respiratory distress syndrome, etc. On the other hand, liberal fuid infusion can reduce postoperative complications such as nausea, vomiting, and drowsiness.

For major systemic surgeries, the current trend is either to follow a 'restrictive' approach or a goal-directed therapy. Goal-directed therapy measures hemodynamic parameters such as stroke volume, and fuids are given accordingly. While this has been found useful in major surgeries, particularly abdominal surgeries, there is no evidence on its effectiveness in postoperative recovery for maxillofacial surgery. A liberal approach may be preferred for most kinds of

**Table 12.7** Risks vs. benefts of blood transfusion


**Table 12.8** Indications for postoperative blood transfusion


maxillofacial surgery, which generally fall under low or intermediate risk procedures. Nevertheless, as long as postoperative fuids are being administered, the patient must be monitored for signs of overhydration such as peripheral edema, dyspnea, high blood pressure, and a bounding pulse. If any of these are present, the current fuid regimen must be reassessed [12].

#### **12.2.1.4 Transfusion of Blood and Blood Products**

Postoperative blood transfusion is rarely required in routine maxillofacial surgery. It has been stated that the risks of blood transfusion outweigh the benefts [13] (See Table 12.7), and currently a restrictive approach to blood transfusion is favored.

If there has been extensive blood loss during surgery, or preexisting anemia, the postoperative hemoglobin must be assessed, and the decision to transfuse is based on this level [14]. This is described in Table 12.8.

#### **12.2.2 Postoperative Medication**

The maxillofacial surgeon must be aware of the type and dosage of medication that is required in the immediate postoperative period. Pain control and prophylaxis against infection are the most important factors to be kept in mind while prescribing medication.

#### **12.2.2.1 Pain Control**

Pain control is an important goal after every surgical procedure as it can not only affect the patients' attitude, but it can also impair oxygenation and thereby delay wound healing. The pain must be assessed subjectively, by asking the patient to rate their pain on a standard scale (e.g. Visual Analogue scale or Faces pain scale). If the patient is in pain, pain medication must be increased or changed.

Preemptive analgesia is an evolving, controversial technique that involves the administration of analgesics prior to the onset of noxious stimuli. This is believed to limit the sensitization of the nervous system, thereby reducing the need for postoperative analgesia [15]. One effective preemptive technique is the infltration of a long-acting local anesthetic, such as bupivacaine, into the incision site before closure. This provides effective pain relief throughout the postoperative period.

In the postoperative period, various classes of analgesics may be used [16]. Some of the commonly used analgesics are summarized in Table 12.9.

The best method of choosing the appropriate analgesic is using the WHO analgesic ladder (Fig. 12.1). If the pain is not well controlled, the patient can move to the next step of the ladder. Once the pain is controlled, patients must be weaned by moving down the ladder [17]. This step ladder approach is just a broad lattice and has its own share of controversies and modifcations. Readers are encouraged to read appropriate references for getting a broader picture of the analgesic ladder and a detailed discussion is beyond the scope of this chapter.

**Patient-controlled Analgesia** Postoperative patients often require immediate pain relief at varied intervals. PCA allows the use of iv pumps which, when the patient presses a button, allows a bolus dose of analgesic to be delivered for immediate relief [18]. This allows analgesics to be tailored to the patients' requirements and also records the amount of opioid being administered per day.

#### **12.2.2.2 Anti-infammatory Drugs**

The role of corticosteroids in postoperative care is controversial. Corticosteroids are potent anti-infammatory agents and are often used after surgery. It has been established that corticosteroids reduce pain and infammation [19]. There is also evidence that single doses of steroids can reduce postoperative nausea and vomiting, and improve fatigue after surgery. However, the beneft of extended doses of steroids seems controversial and comes with the risk of impaired wound healing, infectious complications, and hyperglycemia. It is

**Table 12.9** Analgesics commonly used for postoperative pain control


therefore recommended that steroids be used only till the frst postoperative day. Dexamethasone 8 mg is generally used twice a day. For single day dosing, taper is not generally required.

Enzymatic anti-infammatory medication is also used to reduce postoperative edema [20]. These include serratiopeptidase (10 mg tds) or trypsin:chymotrypsin (chymoral, 100,000 IU). However, its effcacy is based mostly on anecdotal reports and there is hardly any scientifc evidence to back its use.

#### **12.2.2.3 Antibiotic Prophylaxis**

The use of antibiotic prophylaxis (for wound infections) in maxillofacial surgery is a controversial area. Literature evidence is insuffcient to ascertain whether prophylaxis is required or not, and the duration of prophylaxis has no defnite guidelines. Based on recent systematic reviews, Table 12.10 sums up current recommendations [21, 22].

Preferred antibiotics for prophylaxis include:

Amoxicillin-Clavulanate 1.2 mg IV bd.

Amoxicillin 500 mg per oral tds (OR) Cefotaxime 1 g IV bd with Metronidazole 500 mg IV tds.

Prophylaxis must be started 30–90 min before the surgical procedure. The postoperative regimen has no clear guidelines, but must continue for at least 24 h after the procedure. After this, the wound must be monitored for infection, and therapeutic antibiotics may be instituted only if required. This section is covered in more detail in Chap. 10, of this book

#### **12.2.2.4 Medication to Prevent Postoperative Gastritis and Vomiting**

Preoperative and intraoperative fasting, as well as drugs used in the postoperative period, can induce gastric irritation in the surgical patient. To counter this, drugs that reduce the acidity of gastric secretions may be used. Ranitidine, a H2 blocker, may be used in a dose of 50 mg bd. An alternative drug is Pantoprazole, which may be used in a dose of 40 mg once a day.

Prevention of postoperative nausea and vomiting is an important factor in postoperative care. One of the important drugs used for the management of PONV is Ondansetron, which is given in a dose of 4 mg [23]. This is usually a rescue medication and is not given on a routine basis.

#### **12.2.2.5 Drugs for Thromboprophylaxis**

Patients undergoing prolonged surgery or hospitalization may be at increased risk of developing thromboembolic events, namely deep vein thrombosis and pulmonary embolism. Additional risk factors include smoking, pregnancy, oral contraceptives, and malignancy. These patients must be placed on thromboprophylactic drugs. In indicated cases, TED (thromboembolic deterrent) stockings have to be used in the postoperative patients. The guidelines are summarized in Table 12.11 [24].

#### **12.2.2.6 Other Drugs That May be Required Based on the Patients' Medical History**

If the patient has other medical comorbidities, medication that was being taken prior to the procedure may need to be continued or modifed. It is best to confer with the patients' physician to determine the dosage and kind of drugs needed. These have been summarized in Table 12.12.

#### **12.2.3 Nutritional Status in the Postoperative Period**

Maxillofacial surgical procedures provide a unique challenge to the nutritional status in the postoperative period. Pain and edema in the oral region often prevent the patient

#### **Fig. 12.1** WHO analgesic ladder

©Association of Oral and Maxillofacial Surgeons of India


Minor oral surgery Weak evidence; physician

judgment

from taking food comfortably, and there is a tendency to eat less or not at all. In patients with intermaxillary fxation, there is an inability to open the mouth and chew food. In certain kinds of surgery, such as reconstructive faps involving the oral region, the patient is asked to avoid taking food by mouth at all to prevent the possibility of infection and fap failure in the postoperative period.

It is important, however, that the nutritional status is maintained. Inadequate nutrition has been shown to increase morbidity and mortality and can delay wound healing. It also increases the patient's susceptibility to infection. In the young, healthy adult patient, nutritional support may not be required, as the body compensates for decreased intake by increased glycogenolysis, gluconeogenesis, lipolysis, and amino acid oxidation. However, in young children, patients

#### **Table 12.11** Thromboprophylaxis guidelines


**Table 12.12** Additional drugs that may be required in the postoperative period


with preexisting malnutrition, and patients with wasting diseases, supplementation may be required for even routine procedures. Patients who do not have adequate oral intake for 7–14 days (3–10 days in children) will require support to avoid malnutrition [25].

Nutritional status must be evaluated in the postoperative patient. This usually calls for consultation by a dietician. For long-term patients, nutritional status can also be measured using certain tools. The accepted tool for assessment is the subjective global assessment scale [26].

In patients on intermaxillary fxation, the classic use of the nasogastric tube must be discouraged. Patients may be educated on taking food through the retromolar region, using a feeding tube. NG tubes may be reserved for cases in whom oral feeds are contraindicated to avoid infection. Nutritionally complete formulas (e.g. Ensure) are available for enteral feeds. The patient may be started on 50 ml formula every 4 h, and this may be gradually increased in 50 ml increments until the desired target is achieved. After each feed, the tube must be fushed with 30 ml water to prevent blockage.

In cases of extensive neck surgery, where swallowing may be impaired, percutaneous gastrostomy (PEG) or jejunostomy tubes may be placed. For these tubes, infusion feeds (at the rate of 20 ml/h, increased in 20 ml increments every 4 h) may be given.

Total parenteral nutrition is usually not preferred because it has been linked to higher rates of infectious complications as compared to enteral nutrition. Patients who have complete block of the gastrointestinal system or those who cannot tolerate or retain enteral feeds are candidates for TPN. Dextrose solutions are preferred, with a dose of 10–20 g/kg/day of glucose. This is used in conjunction with amino acid solutions (0.5–3.5 g/kg/day) and lipid emulsions (50 ml/hr) [25].

#### **12.2.4 Postoperative Mobilization of the Maxillofacial Surgery Patient**

After the surgical procedure, early mobilization is recommended for all patients. Early mobilization is believed to enhance recovery by reducing the incidence of postoperative complications. It reduces secretions in the lungs, accelerates peristalsis, and improves venous blood fow to the extremities, thereby preventing thrombophlebitis and deep vein thrombosis [27]. Immobilization increases the risk of complications such as DVT and pressure sores. It can also lead to urinary retention.

For most maxillofacial procedures, the patient may be allowed to sit up with legs dangling 6 h after surgery. The patient may be mobilized within 24 h, and it is recommended that they ambulate every 4–6 h (during waking hours) till discharge. Caution must be employed in patients who have had grafts or faps taken from the fbula. While the early mobilization protocol must be followed, protected weight bearing may be employed.

For patients who require prolonged bed rest, the use of alternating pressure mattresses or gel mattress overlays must be considered to prevent pressure sores.

Chest physiotherapy forms an important component of postoperative care. The in-hospital patient is prone to increased lung secretions and infections, which may be cleared using chest physiotherapy.

#### **12.2.5 Management of Complications in the Postoperative Period**

#### **12.2.5.1 Sudden Airway Obstruction**

Maxillofacial surgery and surgery to the neck carry a risk of edema and hematoma developing in the postoperative period that can compress on the airway. The airway must be monitored closely, both in the immediate postoperative period and during the stay in the ward.

If the patient presents with hypoxia and airway obstruction, the head tilt-chin lift-jaw thrust maneuver must be employed. The airway must be checked manually and cleared of obstruction such as vomitus or blood. If the airway obstruction is at or above the oropharynx, insert an airway (such as Guedel's) to keep the passage patent. If there is a hematoma compressing the airway, surgical sutures must be removed to allow a release of pressure. In extreme cases, emergency airway procedures such as cricothyroidotomy may need to be performed.

#### **12.2.5.2 Fever in the Postoperative Period**

Fever is defned as a rise in body temperature above 38 °C (100.4 °F). Postoperative fever represents a diagnostic challenge for most surgeons. Although most cases of fever are self-limiting, some can be serious and need urgent intervention. The timing of postoperative fever often gives a clue as to its diagnosis and management [28, 29].

#### **Immediate Fever (During Surgery or Within the First 24 h).**

Fever in the immediate postoperative period is most likely to be an infammatory response to surgery. The surgical procedure causes *release of pyrogenic cytokines*, which stimulate the anterior hypothalamus to release prostaglandins, causing a rise in body temperature. The extent of fever depends on the amount of tissue trauma, but usually resolves in 24 h. Laboratory and diagnostic workup is not warranted for this kind of fever.

Occasionally, immediate fever can occur due to more serious reasons, and it is important to identify these. *Malignant hyperthermia* is a rare, life-threatening disorder that can manifest in susceptible individuals when they are exposed to inhalational anesthetics, or succinylcholine. There is an immediate rise in body temperature during or up to 1 h after surgery. It may be recognized by an immediate rise in ETCO2, tachypnea, tachycardia, and muscle rigidity. Prompt intervention is required to avoid muscle lysis and organ system failure. Treatment involves immediate intravenous Dantrolene sodium (2.5 mg/kg), repeated every 5 min till reversal occurs, or till the maximum dose is reached (10 mg/kg).

If the fever occurs during or immediately *after a blood transfusion*, it is a sign of transfusion reaction. Transfusion of incompatible (mismatched) blood can cause a severe hemolytic reaction, which, in addition to fever, can present with dyspnea, fever, and myoglobinuria. In such cases, the transfusion must be discontinued immediately. Sometimes, febrile reactions can also occur with compatible blood, due to reaction of recipient antibodies with antigens in the transfused blood. This fever will be accompanied by headache, nausea, and vomiting. Slowing the transfusion may suffce, but it must be stopped if the reactions become severe.

*Adverse drug reactions* can rarely cause fever. This is usually a diagnosis of exclusion, and if suspected, all drugs must be discontinued one at a time to identify the offender. If replacement is necessary, a chemically unrelated drug must be used.

#### **Early Postoperative Fever (24–48 h After Surgery)**

A serious cause of postoperative fever in this time period is *deep vein thromboembolism*. This must be suspected if the patient has known risk factors, such as a history of smoking, malignant disease, prolonged surgery, advanced age, or prolonged immobility after surgery. Diagnosis is made by ultrasound or impedence plethysmography. If present, prompt systemic anticoagulation must be started to avoid fatal pulmonary embolism. The use of Homan's sign (Pain in the calf on forced dorsifexion of the foot) is no longer recommended because of the risk of dislodging the thrombus into circulation. A suspected PE may be confrmed with a ventilationperfusion (V/Q) scan of the lungs.

*Thrombophlebitis* can also cause a rise in body temperature. Any iv line in place for more than 24 h can cause phlebitis. This presents with pain, erythema, and edema at the affected site. The iv line must be removed and replaced, and anti-infammatory drugs may be given. A topical ointment containing heparin and benzyl nicotinate (thrombophob) may be applied locally.

*Atelectasis* was once thought to be a cause of fever, but it is now believed that fever and atelectasis are unrelated, though they can coexist*. Aspiration pneumonia* is more likely to be a respiratory cause of fever, but it presents 3–5 days after surgery.

#### **Delayed Postoperative Fever (After 48 h)**

*Surgical site wound infections* can result in fever 3–5 days after surgery. The surgical site must be examined for pain, swelling, and pus discharge if fever occurs during this period. If an infection is present, it must be managed as detailed in the following sections.

*Aspiration pneumonia* can occur if the gastric fuid is aspirated into the lungs, owing to a depressed cough refex after surgery. The risk increases in patients on maxillomandibular fxation.

#### **Fever Beyond Fifth Postoperative Day**

Fever beyond the ffth postoperative day is usually a sign of systemic infection and needs a diagnostic workup. The most common infections that can occur are *urinary tract infection* and *upper respiratory tract infection*.

Indwelling urinary catheters are the main source of UTIs. Women are at greater risk because they have a shorter urethra; however, both genders can develop UTI if the catheter is in place for more than 72 h. Concomitant signs such as burning sensation on passing urine may be present. Urine will appear cloudy. Diagnosis is best confrmed by urine culture; empirical antibiotics may be started in the meantime.

Respiratory tract infections can range from sinusitis to hospital-acquired pneumonia. In Hospital Acquired Pneumonia (HAP), chest auscultation may reveal crackles or rales, and diagnosis is made by chest x-rays. Treatment is by empirical antibiotics.

A rare infection that can occur beyond the ffth day is *necrotizing soft tissue infection*. Although this is more common after colorectal surgery, cervical necrotizing infection has been reported after maxillofacial surgery as well [30]. Diagnosis may be made by detecting subcutaneous 'gas' on x-rays or CT imaging. Treatment involves the use of broad spectrum antibiotics and fuid resuscitation.

With all systemic infections, blood culture must be done to rule out sepsis. It is also important to monitor the patient's vitals closely to ensure that the patient does not go into septic shock.

It may be of interest to know that in the literature there is a mnemonic of 6 W's, with regard to causes of postoperative fever. The W's being *Waves* (ECG changes, MI), *Wind* (atelectasis, pneumonia), *Water* (UTI), *Wound* (surgical site infection), *Walking* (Venous thromboembolism), *Wonder* drugs(drug-related fever).

The workup for postoperative fever is shown in Fig. 12.2.

©Association of Oral and Maxillofacial Surgeons of India

#### **12.2.5.3 Changes in Pulse and Blood Pressure**

Any gross deviation from the normal vital signs must be looked into. Changes in pulse (tachycardia or bradycardia) are usually associated with changes in the other vital signs as well, and these must therefore be evaluated frst.

Hypotension in the postoperative period can occur due to several causes [6] (Fig. 12.3). Hypotension is usually the result of reduced plasma volume; this may be due to inadequate fuid resuscitation, or ongoing blood loss. Excessive usage of opioid analgesics may also cause a fall in blood pressure. A myocardial infarction and blood sepsis may also present with hypotension. Hypotension with tachycardia can be a sign of developing shock; which must be treated immediately with a fuid challenge (rapid bolus of fuid). Regardless of the cause, hypotension must be managed by increasing fuid input and supplemented by high-fow oxygen to improve the perfusion.

Raised blood pressure usually occurs in patients who have had preexisting hypertension. If the patient has a history of ischemic heart disease or cerebrovascular disease, it must be managed with appropriate medication, to reduce the risk of developing myocardial infarction or stroke postoperatively. Sometimes, hypertension may occur in healthy adults with no history. In these cases, it could refect pain and anxiety, or distension of the bowel and/or bladder. Excessive fuid resuscitation may also result in hypertension [6].

#### **12.2.5.4 Changes in Respiration**

Increase in respiratory rate (tachypnea) is usually a sign of respiratory distress, and may be accompanied by decreased

**Fig. 12.3** Postoperative hypotension workup

oxygen saturation, and use of accessory muscles of respiration [6]. Sudden acute shortness of breath may be a sign of pulmonary embolism. Gradual onset that occurs within 2–5 days of surgery is commonly due to atelectasis. Atelectasis is the collapse of a small segment of the lung and commonly occurs after general anesthesia. Atelectasis after maxillofacial surgery may be obstructive in nature, occurring secondary to epistaxis or mucus secretion. Another reason for the slow onset of respiratory distress is Acute Respiratory Distress Syndrome (ARDS), which can occur secondary to hypovolemia, sepsis, or trauma. Respiratory infection and cardiac causes such as myocardial infarction or cardiac failure can also alter respiratory rate. The various causes are illustrated in Fig. 12.4.

If a person experiences shortness of breath, high-fow oxygen must be started, and a chest x-ray and EKG must be taken. Laboratory tests including cardiac enzymes and arterial blood gases must be performed to ascertain the cause. If sputum is present, it must be sent for culture and gram staining.

#### **12.2.5.5 Postoperative Nausea and Vomiting**

This is a common complication that occurs due to activation of the nucleus tractus solitarius and vomiting center by inhalational anesthetics. Patients who undergo maxillofacial surgery, particularly orthognathic surgical procedures, are at increased risk of developing postoperative nausea and vomiting, due to accumulation of blood in the throat. It can affect 20–80% of all patients, the risk being higher in young patients, females in the frst 8 days of their menstrual cycle, and obese patients [23]. This complication is best managed symptomatically using antiemetics such as ondansetron and metoclopramide.

#### **12.2.5.6 Oliguria and Acute Renal Failure**

The normal urine output is 1 ml/kg/h in infants, 0.5 ml/kg/h in children, and at least 400 ml/day in adults. Any drop below this level is referred to as oliguria and this must be addressed to prevent acute kidney injury (AKI). AKI is diagnosed as oliguria, along with serum creatinine levels 1.5 times above baseline [6]. The various causes of postoperative oliguria and management are outlined in Table 12.13.

**Fig. 12.4** Postoperative respiratory distress workup

**Table 12.13** Types of postoperative oliguria and management


#### **12.3 Care of the Surgical Wound Site**

#### **12.3.1 Immediate Care in the Operating Room**

Care of the surgical wound site begins even before closure of the wound has been completed. It may be necessary to place drains or catheters within the wound.

#### **Surgical Drains**

A drain is a device that is intended to evacuate fuids and air from the surgical wound site. By evacuating accumulated pus, blood, and serous fuid, they help prevent infection of the surgical site. By evacuating air, they help eliminate dead spaces, which results in faster wound healing.

The various kinds of drains are summarized in Table 12.14. Drains may be classifed as:


Technique of inserting a surgical drain:


#### **Table 12.14** Types of drains


#### **Surgical Site Catheters**

Catheters may be inserted directly into the surgical site beneath the skin sutures. These may serve the following purposes:


#### **Wound Dressing**

Once complete suturing of the wound has been completed, appropriate dressing of the wound site must be carried out. Various types of dressing material are available [31]. These are detailed in the Chap. 11 on soft tissue injuries and management.

#### **12.3.2 General Guidelines for Postoperative Wound Care** [32]


#### **Postoperative Care of Drains and Catheters**


Surgical site catheters must be removed by the third postoperative day.

#### **12.3.3 Surgical Site Complications**

#### **Postoperative Bleeding, Hematoma, and Seroma**

Bleeding after surgery is classifed as primary (occurs during or immediately after the surgical procedure), reactionary (occurs after few hours, possibly due to slipped ligatures), and secondary (occurs after few days, commonly due to infection). Active, ongoing bleeding is referred to as hemorrhage.

Hematoma refers to a clotted collection of blood below the tissues, which occurs due to damage to vessel walls. Most hematomas are self-limiting. Larger hematomas can be treated with ice packs or compression dressings. Analgesics may be given if the swelling is painful. Hematomas in the submandibular and neck region, or other regions which can potentially compress the airway, must be drained surgically.

Seromas are collections of serous fuid that generally develop 5–7 days after surgery. They are more common in extensive surgeries, particularly in neck dissection, where lymph nodes have been removed. Small seromas resolve over time. If the seroma is large and painful, the fuid may be aspirated and a pressure dressing can be applied.

#### **Infected Wound**

As maxillofacial procedures are clean-contaminated surgeries, they carry a higher risk of developing infection as compared to clean surgeries. Signs and symptoms of an infected wound include:


If the wound appears infected, a few sutures must be removed and pus must be drained out. A swab must be sent for culture and sensitivity testing, and the patient must be started on empirical antibiotics. The patient must be monitored closely for signs of systemic infection. The infected wound can be treated by local debridement and antibiotic irrigation.

#### **Wound Dehiscence**

This generally occurs as a result of one of the above complications, most commonly subacute infection. Sometimes, however, it may simply be the result of excessive wound tension due to inadequate tissue undermining. If the wound is uninfected less than 24 h postoperatively, re-suturing may be attempted. Otherwise, the wound is best left to heal by secondary intention. Resistant wound dehiscence may lead to orocutaneous communications and may become diffcult to handle. The decision to either allow these to granulate or surgically provide a cover depends on individual scenarios.

### **12.4 Postoperative Care for Specifc Types of Surgeries**

While the general rules apply to all kinds of surgeries, there may be extra measures which are required in each specifc surgery type. These are outlined below [2].

#### **Postoperative Care for the Trauma Patient**


#### **Postoperative Care for Orthognathic Surgery Patients**


#### **Postoperative Care for Oncology and Reconstruction Patients**

• These patients usually undergo extensive surgery that lasts for hours, and will therefore need intensive monitoring in the postoperative period. Tracheostomy care may be required (See Sect. 12.1.1).


#### **Flap Monitoring**


#### **12.5 Postoperative Complications Specifc to each Type of Surgery**

Table 12.15 lists the complications that may be encountered with each specifc surgery.

#### **12.6 Criteria for Discharging the Patient**

Prolonged hospital stay increases the patient's risk of developing nosocomial infections. Therefore, the patients must be discharged as soon as feasible. Criteria for discharge are as follows:


Discharge summary: This is a record given to the patient, detailing the diagnosis, procedure performed, and any implants that were used. Instructions and medications to be taken must also be noted.

Follow-up appointments must be made for review. In case facial and neck incisions were placed, an appointment for suture removal must be given.


**Table 12.15** Specifc postoperative complications

#### **12.7 Conclusion**

Postoperative care requires a thorough understanding of the patient, the procedure they have undergone, and the expected outcome. Surgeons must realize that more often it may be the frst experience for a patient in going under the knife and lying at the ICU or ward. Hence, a perfect coherence of scientifc and psychological views is required of the surgical team at all levels. The chapter emphasizes the need for comprehensive management of the maxillofacial patient at the ward after their procedure. The reader is expected to understand that outcome depends, but not ends at operating room or ward/ICU.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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**Part VI**

**Dentoalveolar and Oral Surgery**

## **Principles and Techniques of Exodontia**

Anuj Jain

#### **13.1 Introduction**

Exodontia is the removal of tooth from its socket in the alveolar bone with the help of anesthesia. It is a challenging procedure in itself as the dental surgeon has to work in an oral cavity, access to which is restricted by patient's lips and cheeks. Also, the movement of the tongue and the jaw makes the procedure troublesome. Another factor which complicates the procedure is saliva. The oral cavity communicates with the pharynx which further communicates into larynx and esophagus, due to which there is always a potential risk of aspiration or deglutition of the extracted tooth. Hence, it is of paramount importance that the exodontia must be performed judiciously and be based on sound surgical principles.

Apart from the competence and practical skills of the dental surgeon, patient's cooperation also holds the key to an uneventful extraction of a tooth. Patient's cooperation is dependent on various factors like misinformation, myths, anxiety, pain phobia, patient's previous exodontia experiences, and trust over the operator. A dental surgeon must have a calm, patient, and reassuring approach towards the patient to gain his/her confdence. This empathetic nature of the doctor must be superadded with good principles of patient management and pharmacokinetics. This combination helps in controlling patient's anxiety and fear toward the procedure.

### **13.2 Defnition**

Exodontia or tooth extraction is defned as the painless removal of a whole tooth or tooth root, with minimal trauma to the investing tissues, so that the bone heals uneventfully and no postoperative prosthetic problem is created [1].

### **13.3 History**

The thought of how extractions were performed in eleventh century is disturbing. The operator used to hold the patient's head between his knees, the soft tissue was cut with a sharp scalpel, and the tooth was pulled out in single direction. Often the wound was cauterized with a red hot iron and a repellent mouthwash was prescribed [2].

Historically, dental extractions were carried out as a prophylactic as well as therapeutic treatment for a variety of illnesses. Before the discovery of antibiotics, exodontia was a preferred treatment. Dentistry was not a separate profession at that time and mainly the barbers were extracting the tooth popularly known as 'barber surgeons'. They used to hang rows of rotten teeth outside their shops to advertise their services as tooth pullers [3].

Various kinds of instruments were used in different geographical areas of the globe and can be grouped as forceps, pelicans, keys, screws, and elevators. The modern-day forceps have been evolved over time and are highlighted in Table 13.1.

Regarding Indian history, Sushruta is to be credited for his description of surgical instruments. He highlighted two types of instruments viz. 'Yantra or blunt' and 'Shastra or sharp'. And among the category yantra, 'dantasanka' – a special forceps for extraction of teeth is described [6]. Vagbhata, around 650 AD, described forceps for extraction of tooth [7].

### **13.4 Applied Surgical Anatomy**

*Knowledge of Anatomy is the foundation for an uneventful surgery.*

The jaw bones namely maxilla and mandible harbor the teeth in their respective alveolar process within the shapeappropriate sockets designed by nature. Sharpey's fbers of periodontal ligament attach the teeth to their alveolar sockets with the joint called gomphosis.

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 259

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_13

A. Jain (\*)

Oral and Maxillofacial Surgeon, Department of Trauma and Emergency Medicine, All India Institute of Medical Sciences, Bhopal, Madhya Pradesh, India


#### **Table 13.1** Evolution of dental forceps

#### **13.4.1 Maxilla** (Fig. 13.1)

It is a paired bone forming the midface of a person, bearing upper teeth separating the oral cavity from the nasal cavity and maxillary sinuses. Compared to the mandible, it is composed of spongier bone with thinner cortical plates. Palatal processes extend from both the maxillary bone and meet in the midline to form the roof of the oral cavity. The branches of *Maxillary Nerve* innervate the maxillary teeth and their periodontium (Table 13.2).

Exodontia becomes easier in maxilla due to following reasons:


Following factors complicate exodontia of maxillary teeth:

	- (a) Oroantral communication during the extraction of maxillary molars.
	- (b) Spread of periapical infection into the sinus leading to odontogenic maxillary sinusitis.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 13.1** Alveolar process of maxilla


#### **13.4.2 Mandible** (Fig. 13.2)

It is horseshoe shaped, mobile and the heaviest bone of the craniofacial skeleton. Compared to maxilla, it has less spongy bone as well as vascularity and has thick cortices. The branches of *Mandibular Nerve* innervate the mandibular teeth and their periodontium (Table 13.3).


GPN: Palatal soft tissue


Abbreviations: *ASAN* Anterior Superior Alveolar Nerve, *NPN* Nasopalatine Nerve, *MSAN* Middle Superior Alveolar Nerve, *GPN* Greater Palatine Nerve, *PSAN* Posterior Superior Alveolar Nerve

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 13.2** Alveolar process of mandible



Following factors complicate exodontia of mandibular teeth:

Greater palatine nerve block


#### **13.4.3 Teeth**

Apart from the bone, the anatomy of teeth also plays a pivotal role in an uneventful extraction. The shape of crown and roots must be assessed carefully, preoperatively. A narrow tapering crown requires the use of a lighter beaked forceps whereas a bulbous crown needs to be extracted using heavy beaked forceps. If the tooth is multirooted, it offers more resistance than a single-rooted tooth and cannot be extracted using a rotational force, as such a motion will lead to root fracture. In cases where the roots are divergent, the application of heavy forces will lead to root fracture. Dilacerated roots are also prone to fracture on the application of injudicious forces. Also, a more careful approach is required while extracting non-vital and endodontically treated teeth, as they fracture readily due to their fragile and brittle nature secondary carious undermining and loss of pulpal tissue.

#### **13.5 Indications for Exodontia**

Extraction of the teeth can be either prophylactic or therapeutic. Following are the indications for exodontia (Box 13.1).

	- (a) Malposed teeth: The teeth which are misaligned and cannot be reoriented within the proper arch form with orthodontic treatment.

#### Indications of Exodontia


©Association of Oral and Maxillofacial Surgeons of India

**Box 13.1** Indications of exodontia


#### 13 Principles and Techniques of Exodontia

**Fig. 13.3** (**a**) Intraoral periapical radiograph showing grossly carious second molar indicated for extraction. (**b**) Clinical Photograph showing pulpal pathology. (**c**) Clinical Photograph showing generalized periodontitis. (**d**) Radiograph showing developing root caries following endodontic treatment. (**e**) Radiograph showing fractured central inci-

sors. (**f**) Clinical Photograph showing root pieces. (**g**) Clinical Photograph showing supernumerary teeth. (**h**) OPG showing impacted mandibular canine. (**i**) OPG showing left mandibular third molar in fracture line. (**j**) OPG showing cyst associated with impacted maxillary canine

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 13.3** (continued)

#### **13.6 Contraindications for Exodontia**

A tooth may be indicated for extraction, but the presence of certain factors makes it contraindicated for extraction at that particular time. Any medical disorder in an uncontrolled, severe, or acute state may become a relative contraindication for extraction. However, once the underlying medical condition is controlled, the patient may be ft to undergo extraction. These relative contraindications may be classifed as systemic or local contraindications.

#### **13.6.1 Systemic Contraindications**

Any uncontrolled systemic disease becomes a relative contraindication.


#### **13.6.2 Local Contraindications**


However, if it is unavoidable, may be performed, but meticulously.


#### **13.7 Armamentarium for Exodontia** [10, 11]

#### **13.7.1 Forceps**

Forceps are the basic instruments used to perform exodontia. They are based on principles of simple machines. Forceps are designed to provide adequate access to the targeted tooth without injuring the neighboring tissues. Forceps basically have three components: (Fig. 13.4).

• The handle: Handle is the area of forceps from where the operator holds the instrument in a palm grip. It has serrations to facilitate frm grip. It is longer as compared to the beaks,

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corresponding to the longer arm of the lever, providing maximum mechanical advantage.


The forceps are of two types:


Tables 13.4 and 13.5 describe various maxillary and mandibular forceps with their salient features, respectively.

Maxillary forceps must be held in a 'palm up' position (Fig. 13.7a) and mandibular forceps must be held in a 'palm down' position (Fig. 13.7b). These forceps majorly apply fve different motions: (Fig. 13.8).



**Fig. 13.5** (**a**) Maxillary anterior forceps, (**b**) Maxillary premolar forceps, (**c**) Maxillary molar forceps, (**d**) Maxillary cow horn forceps, (**e**) Maxillary third molar forceps, (**f**) Maxillary bayonet forceps

**Fig. 13.5** (continued)

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**Fig. 13.5** (continued)


269

**Fig. 13.6** (**a**) Mandibular anterior forceps, (**b**) Mandibular premolar forceps, (**c**) Mandibular molar forceps, (**d**) Mandibular cow horn forceps, (**e**) Mandibular third molar forceps, (**f**) Mandibular molar forceps (American pattern)

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**Fig. 13.6** (continued)

5. Tractional forces: This delivers the tooth out of the socket. This force should be gentle and the tooth should not be pulled out of the socket. However, if excessive force is required, other maneuvers must be carried out to improve luxation.

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**Fig. 13.7** (**a**) Correct way of holding maxillary forceps, (**b**) Correct way of holding mandibular forceps

#### **13.7.2 Elevators**

Elevators are the instruments used for luxating (loosening) the teeth before application of forceps making extraction easier, subsequently avoiding complications like fracture of crowns, roots, and bone. They are also used to remove fractured or surgically sectioned roots. Elevators are singlebladed instruments designed for specifc purposes deliver-

Apical Pressure Buccal/Labial Pressure

**Fig. 13.8** Sequential motions performed using forceps

**Fig. 13.9** Center of rotation of tooth gets displaced apically when the forceps is inserted beyond cementoenamel junction

B

L

L

B

ing maximum mechanical advantage with minimum efforts. Elevators have three components (Fig. 13.10):


Table 13.6 highlights various types of elevators used for exodontia and Fig. 13.12 shows the proper way to hold an elevator.

L

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**Fig. 13.10** Components of elevator

Elevators works on principles of


**Table 13.6** Elevators with their salient features


**Fig. 13.11** (**a**) Straight elevator, (**b**) Coupland elevator, (**c**) Apexo elevator, (**d**) Cross bar elevator, (**e**) Cryer elevator, (**f**) Warwick James elevator, (**g**) Root tip elevator

**d**

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**Fig. 13.11** (continued)

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#### **13.8 Sequential Procedure of Exodontia**  [6, 10]

The procedure of exodontia is a blend of surgical principles and elementary physics mechanics. When this combination is applied effciently, a tooth can be removed with no great diffculty and fnesse without requiring a large amount of force. For an uneventful extraction to be carried out, a proper sequential procedure must be followed.

#### **13.8.1 Presurgical Assessment**

	- The approach of a dental surgeon must not be localized to a diseased tooth. It should always be kept in mind that we are not treating a tooth but we are treating an individual with a diseased tooth. It is critical that the surgeon must examine the patients' medical status. Patients may suffer from a variety of medical ailments requiring modifcation in treatment planning. Medical management must be carried out frst for safe extraction procedure for the patient.

Due to various myths like weakening of eyesight and impact on mental health following extraction as well as severe intolerable pain during the procedure, the patients are generally apprehensive to undergo extraction. Such patients are liable to go into syncope or aggravation of their medical condition. A proper counseling is required in such cases before proceeding for exodontia. However, in extremely anxious patients, where counseling is not enough, premedication like Diazepam/Alprazolam (Anxiolytics) for reduction of anxiety may be considered.

• Extraoral Examination:

The patient must be examined for the presence of any extraoral swelling, cellulitis, abscess, or lymphadenopathy. Presence of any swelling is suggestive of extension of infection into surrounding soft tissue space which may require another surgical procedure. Presence of trismus must also be examined as it affects the access to the tooth to be extracted.

• Intraoral Examination:

It includes an examination of the size of the tongue, bulky buccal fat pad, and hyperactive gag refex as these fac-

277

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**Fig. 13.14** (**a**) The small force and large movement transformed to small movement and large force by the frst-class lever, (**b**) The tooth is elevated out of the socket where the bone acts as a fulcrum

**Fig. 13.15** The elevator acting on the principle of Wheel and Axle aids in retrieval of root from the socket

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tors may hamper the access to the surgical site. Acute signs of infection like infammation, edema, and pus discharge must also be assessed and the procedure must be performed under local antiseptic care and antibiotic coverage.

	- This step includes a thorough examination of
	- Crown size
	- Form
	- Shape
	- Presence of caries
	- Mobility
	- Previous endodontic therapy
	- Tooth Angulation
	- Malposition

These factors play a signifcant role in the extraction procedure. The status of the adjacent tooth should also be examined as in its absence the interdental bone cannot be used as a fulcrum. Moreover, if it is carious, there are chances of fracture of the adjacent tooth while application of elevator in the interdental space.

• Radiographic Examination.

It is advisable to take a proper radiograph for any tooth which is to be extracted. Generally, an intraoral periapical radiograph provides accurate and suffcient details of the tooth, its root/s, and the surrounding tissue.

Examination of the following factors must be done:


A proper radiograph also gives an idea regarding the proximity of the root to the vital structures such as inferior alveolar neurovascular bundle and maxillary sinus. Moreover, the condition of surrounding bone can also be identifed for the presence of sclerotic bone or periapical pathologies like cyst, abscess, or granuloma.

#### **13.8.2 Treatment Planning**

As the proverb says '*Failing to plan is planning to fail'*, it is of paramount importance to device a proper treatment plan before carrying out an extraction procedure. The degree of diffculty must be anticipated during the pre-extraction period. On assessment, if it is believed that the degree of extraction is high or the initial attempts of extraction confrm it, a deliberate surgical approach must be planned. A large amount of force during simple exodontia must be avoided as it may injure local soft tissue and damage surrounding bone and teeth. There are also chances of crown fracture which makes the procedure more diffcult. Also, the application of excessive force aggravates the intraoperative and postoperative discomfort of the patient.

#### **13.8.3 Administration of Local Anesthesia**

Extraction of the tooth can be effectively carried out under local anesthesia. Hence, administration of local anesthesia must be carried out with proper technique and appropriate agent. For different teeth, different nerve blocks are to be given (Tables 13.2 and 13.3). Once the local anesthesia, nerve block and/or local infltration is administered, surgeon must wait for it to act and confrm the same by subjective and objective tests.

#### **13.8.4 Surgeon and Patient Preparation**

The principle of universal precaution states that all the patients must be viewed as having blood-borne diseases that can be transmitted to the surgical team and other patients. Hence, to avoid transmission of diseases, a surgeon and the assistant must wear surgical gloves, surgical mask, eye-wear with shields, surgical cap, and a long-sleeved surgical gown. Before the patient is subjected to the extraction procedure, a sterile drape should be put over the patient's chest to decrease the risk of contamination. It is advisable to reduce the bacterial contamination in the patient's mouth by making him/ her rinse the mouth vigorously using an antiseptic rinse like chlorhexidine prior to the procedure. Some surgeons prefer to keep a partially unfolded 4 × 4 inches' gauze loosely into the back of the mouth to prevent the tooth or its fragment from potential aspiration or swallowing. However, it should not be kept posterior enough to trigger gag refex.

#### **13.8.5 Position of Operator, Patient, and Chair**

The positions of the operator, the patient, and the chair are very important for comfortable and successful extraction. The best position is one that is comfortable for both the patient and surgeon and which allows the surgeon to have maximum control during the procedure.


**Table 13.8** Operator's standing position for extraction



#### **13.8.6 Exodontia Procedure**

Choosing the correct technique and following fundamental principles, leading to an atraumatic extraction. The three fundamental requirements for a good extraction are:


Dental extractions are based on three mechanical properties, which are as follows:

1. *Expansion of alveolar socket*: The tooth itself is used as a dilating instrument to expand the alveolar socket in order to permit the removal of its harbored tooth. This is performed mainly in 'intra-alveolar exodontia' by holding the tooth frmly with a forceps and carrying out lateral movements in buccal and lingual directions (Fig. 13.18). This expansion depends on the elasticity of the bone which is maximal in young bone and decreases with age. Dilatation of socket results in microfractures in the bony 280

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**Fig. 13.16** Operator's position for maxillary teeth extraction, (**a**) Right posterior, (**b**) Anterior, and (**c**) Left posterior

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**Fig. 13.17** Operator's position for mandibular teeth extraction, (**a**) Right posterior, (**b**) Anterior, and (**c**) Left posterior

wall and interradicular septa. The bony fragments retain the periosteal attachment in almost all the cases and hence must be digitally compressed unless an implant placement is planned.


The two methods of exodontia are as follows:

1. *Intra-alveolar Exodontia*: This method of extraction is also referred to as closed method or routine exodontia, usually practiced for extraction of erupted and intact tooth with enough structure to grasp with a forceps and pull the tooth out of alveolar socket. Instruments used are forceps or elevators or both. This technique is the most frequently used technique for almost every extraction. However, if the operator believes that the extraction will require an excessive force or if a substantial amount of crown is missing or covered by tissue, an open technique may be opted.

5 sequential steps are to be followed for exodontia by closed technique (Fig. 13.20). Other than these 5 steps, the opposite hand also plays a vital role during the procedure which is highlighted in Table 13.9.

**Fig. 13.18** (**a**) Exodontia by expansion of bony socket is similar to the removal of a post embedded in the ground, (**b**) The post is moved laterally in a to and fro motion, (**c**) This results in displacement of soil surrounding the post and permitting the post to be removed out

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**Fig. 13.19** Insertion of wedge-shaped forceps blades resulting in rise of the tooth in the socket

2. *Transalveolar Exodontia:* This method includes removal of alveolar bone to access and extract the tooth. It is generally practiced for extraction of impacted teeth, root pieces, or teeth with unfavorable root form. It is often termed as surgical extraction or complicated exodontia. Indications for open technique are enlisted in Box 13.2. For an open technique exodontia, 5 steps are to be followed: (Fig. 13.23) (Clinical Case, Fig. 13.24a–f).

### **13.9 Various Mucoperiosteal Flap Designs for Transalveolar Extraction**

Transalveolar exodontia necessitates incision making and subsequent mucoperiosteal fap refection for adequate exposure of the underlying alveolar bone. The fap must be an adequate sized full-thickness mucoperiosteal fap with a broader base which is made on intact bone, avoiding injury to the local vital structures. The various types of faps used in transalveolar exodontia are:



**Fig. 13.20** Steps for Intra-alveolar exodontia

#### **Table 13.9** Role of opposite hand during exodontia


aspect of vertical releasing incision, and the superior aspect of the vertical releasing incision. When a greater exposure is required, this fap is preferred (Fig. 13.25b).

3. *Trapezoidal Flap:* When a crevicular incision has two vertical releasing incisions on either sides, it produces a trapezoidal fap. It is also known as a three-sided or fourcornered fap. Two corners are at the superior aspect of the releasing incisions and the other two corners are at the ends of the crevicular incision. The vertical releasing incisions are not vertically placed but are directed obliquely to allow a broader base (Fig. 13.25c).

Transalveolar or complicated exodontia can be further described in two types.

1. *Complicated Exodontia of Single rooted tooth.*

It starts by incision making and refecting a suffciently large fap to provide adequate visualization and access. Mostly an envelope fap is preferred which is extended at least two teeth anterior and one tooth posterior to the tooth that has to be extracted. If required, a releasing incision can be placed. Once the fap is refected adequately and the surgical site is exposed suffciently, extraction of the tooth/ root must be performed by using one of the various options.

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**Fig. 13.21** Pinch grasp for maxillary teeth (**a**) Right posterior, (**b**) Left posterior

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**Fig. 13.22** Sling grasp for mandibular teeth (**a**) Right posterior, (**b**) Anterior


**Box 13.2** Indications of transalveolar exodontia

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**Fig. 13.23** Steps for transalveolar exodontia

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**Fig. 13.24** Transalveolar extraction of impacted tooth: (**a**) IOPA showing impacted tooth, (**b**) Incision and fap refection (Triangular fap), (**c**) Bone removal, (**d**) Extraction socket (**e**) Closure, (**f**) Extracted tooth

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enough to engage the tip of an instrument to be used for elevation of the tooth.

Once the tooth is delivered, the sharp bony edges must be smoothened using a bone fle and the whole surgical site must be thoroughly irrigated using copious amount of sterile saline. The fap must be repositioned and sutured into place.

2. *Complicated exodontia of multirooted teeth.*

If a treatment plan of complicated exodontia is devised for a multirooted tooth, it is extracted with the same technique as of single-rooted tooth. The only difference is that the tooth is divided using a bur to convert into two or three single-rooted fragments (odontectomy). Following incision and fap refection, once the tooth is converted into multiple single-rooted fragments, the extraction procedure is carried out in a similar way as of single-rooted tooth. Also, the immediate postoperative procedures like smoothening of bony fragments, irrigation, and closure also remains the same. The following text describes different techniques of splitting a multirooted tooth in different scenarios.

(a) Mandibular molar with intact crown: First step involves the exposure of bifurcation by removing a small amount of crestal bone. The tooth is usually sectioned buccolingually to split the tooth into mesial and distal halves (Fig. 13.27a). These halves are then mobilized using a straight elevator and are treated as two single-rooted teeth. These teeth are then extracted with the help of mandibular premolar forceps.

Alternatively, mesial root is sectioned using a bur to convert the molar into single-rooted tooth (Fig. 13.27b). The tooth along with distal root is removed with the help of forceps followed by the removal of mesial root. This mesial root is extracted with the help of a Cryer elevator.


causes less morbidity than the closed technique as the extraction of maxillary molar requires excessive force during forceps' extraction. Once the flap is raised, a small amount of crestal bone is removed to expose the trifurcation. With the help of a straight bur, the mesiobuccal and distobuccal roots are sectioned horizontally at the level of trifurcation. This separates the two buccal roots converting the molar into single-rooted tooth (Fig. 13.27d). The molar with palatal root is then extracted using the maxillary molar forceps with gentle but firm bucco-occlusal forces. The two buccal roots are then mobilized with the help of a straight elevator. These roots are then delivered out with the help of a straight or Cryer elevator. The operator must take precaution to maintain controlled force in an apical direction during removal of these roots using the straight elevator as maxillary sinus might be in a close proximity to these roots. Uncontrolled and excessive force may result in an oroantral communication or displacement of the root into the sinus.

(d) Maxillary molar with lost crown: A small amount of buccal bone is removed to expose the roots and is divided into two buccal and palatal roots (Fig. 13.27e). The roots are mobilized with the help of a straight elevator and are extracted with the help of bayonet forceps or Cryer elevators. Generally, buccal roots are approached frst followed by palatal root.

During exodontia, once completed either by closed technique or by open technique, a few important things must be kept in mind which are listed in Box 13.3 and the patient should be instructed properly as listed in Box 13.4. During exodontia, either closed or open, an assistant may be really helpful and plays an important role during the procedure (Box 13.5).

#### **13.10 Multiple Extractions**

If multiple adjacent teeth are indicated for extraction, a few key points are to be taken into consideration.


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**Fig. 13.26** (**a**) A small portion of buccal bone is grasped along with the root in cases when the root is fractured at the level of alveolar bone (Alveolar Purchase Technique), (**b**) A small straight elevator is being

used to luxate the broken root, (**c**) Bone is removed from the buccal aspect of the root using a bur

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**Fig. 13.27** (**a**) Sectioning of tooth into mesial and distal halves, (**b**) Separation of mesial root from the tooth, (**c**) Separation of roots of mandibular molar, (**d**) Buccal roots are sectioned from the tooth, (**e**) Separation of roots of maxillary molar

#### **Box 13.3** Immediate

post-extraction care

#### Immediate Post -extraction Care


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**Box 13.4** Postoperative instructions

#### Post-operative Instructions


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	- (a) Infltration anesthesia has a more rapid onset in maxilla leading to early start of the procedure.
	- (b) Profound anesthesia is lost early in maxilla.
	- (c) If mandibular teeth are extracted frst, debris such as fractured crowns, bone chips, and portions of restorative material may fall in the empty mandibular sockets during extraction of maxillary teeth.

#### Role of Assistant during Exodontia


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**Box 13.5** Role of assistant


### **13.11 Extraction of Root Fragments and Tips**

Ideally, when the apical one-third of the root (3–4 mm) is fractured, it should be removed as it may act as a septic focus or may result in the formation of cyst or other pathologies. To extract these root tips, the two most important requirements are excellent light and excellent suction with a tip of small diameter.

Once the fracture of root tip has been diagnosed, the operator must reposition the patient to achieve proper visualization and suction. Initially, closed technique must be attempted; if unsuccessful, then the open technique must be carried out for retrieval of root tip.


hole and the root fragment is guided out of the socket (Fig. 13.28c and d).

However, if the risk during retrieval of root fragment is comparatively more than the beneft of its removal, it is advisable to leave the root in situ. If the surgeon decides to retain the root, it should be documented and informed to the patient. The criteria for retaining the root are highlighted in Box 13.6. The policy of dealing with fractured apical root tips of maxillary molars and the management of root tips displaced into the antrum is elaborated in Chap. 24 of this book.

#### **13.12 Extraction During Menstruation**

If permissible, extractions should be avoided during menstruation because during this period there is a high level of estrogen circulating in the blood streams which results in increased tissue bleeding. Menstrual cycle could be a determinant risk factor for alveolar osteitis. Also, both exodontia and menstruation are stressful conditions, it is better not to subject the patient to increased stresses [12].

#### **13.13 Extraction During Pregnancy**

*Pregnancy*: Second trimester is considered to be relatively safer for carrying out minor oral surgeries. However, in other trimesters, if the potential risk of retaining the tooth outweighs the complications of performing the surgery, one must plan to carry out extraction with the utmost care and avoiding use of drugs and radiographs as much as possible. Caution should be exercised to evaluate teratogenic potential of drugs when prescriptions are warranted.

During frst trimester, the fetus is at risk of developmental defects if the extraction is carried out as it undergoes organogenesis. The best course of action is to prevent the patient from all kinds of infection. During the third trimester, there are chances of premature labor or even an abortion. However, if an exodontia is planned, the patient must be kept in a left lateral position. If the patient is maintained in a supine position, there are chances of obstruction of venous return resulting in supine hypotension syndrome [13, 14].

#### **13.14 Healing of Extraction Socket** [15]

Along with understanding the general principles of exodontia, it is pivotal for a dental surgeon to thoroughly know the phenomenon of healing of extraction wounds. An extraction socket heals in a similar fashion as any other wound in the body except for minor variations which occur due to the anatomic structures in and around the socket.

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**Fig. 13.28** (**a**) The root tip elevator is inserted into the periodontal ligament space to elevate the root tip, (**b**) Open technique for removal of fractured root fragment, (**c**) Open Window technique for removal of fractured root fragment, (**d**) Clinical picture of open window technique

**Box 13.6** Criteria for retaining root piece

#### Criteria for leaving root piece in situ


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Blood present in the socket immediately after extraction of tooth coagulates and red blood cells become entrapped in the fbrin meshwork. This initial time period postextraction is critical because if the clot dislodges, healing becomes delayed and painful. Alterations in the vascular bed such as vasodilatation along with engorgement of blood vessels of periodontal ligament and transport of leukocytes around the clot occur during frst 24–48 hours. A thick layer of fbrin covers the clot which shows signs of contractions. This clot forms a scaffold over which cells associated with healing grow.

In the frst week following extraction, fbroblasts from remnants of PDL begin to grow in the periphery of clot and a thick layer of leucocytes gather over the clot. Osteoclastic activity starts in the crest of alveolar ridge. Blood clot undergoes organization by fbroblast and endothelial cell proliferation, signaling the growth of small capillaries in the PDL area.

Epithelial proliferation over the surface of the clot increases during the second week of healing leading to a more organized blood clot with new capillaries in the center. Remnants of PDL undergoing degeneration are no longer visible. Margins of alveolar socket appear frayed due to osteoclastic activity. Surfaces of small wounds epithelize completely by this time.

By the third week, fbrin meshwork of the original clot is replaced by mature granulation tissue. Young trabeculae formed by osteoblasts derived from pluripotent cells of PDL form around the periphery of wound. Crest of alveolar bone appears rounded due to resorption. All kinds of wound epithelize by this stage of healing.

Wound enters the fnal stage of healing in the fourth week. There is deposition and resorption of bone of alveolar socket which continues for several weeks. Newly formed bone is poorly calcifed; therefore, the bone after extraction becomes radiographically evident only after 6–8 weeks. Loss of crestal and buccal bone during transalveolar extractions leads to smaller alveolar ridges post healing.

#### **13.15 Complications of Exodontia** [10]

Surgical procedures are associated with complications and exodontia is no different. Various complications related to exodontia are highlighted in Table 13.10.

Modalities to manage hemorrhage are as follows:


• Tying or coagulation of visible blood vessel.

*Displacement of tooth in Antrum*: Operator must be careful while extracting maxillary molars to avoid displacement of tooth/root into maxillary antrum. Excessive and uncontrolled force in the apical direction may lead to displacement of tooth/root in the maxillary sinus. If displaced, it can be retrieved by carrying out sinus exploration [16].

*Displacement into adjacent spaces*: Tooth/root might get displaced into adjacent anatomic spaces. If it happens, retrieval must be attempted. However, delayed retrieval can also be done as foreign body reaction aids in localization of the tooth/root [17].

*Loss of tooth in pharynx*: During exodontia, if the tooth is lost in pharynx, one must get a chest radiograph done to rule out aspiration. If the tooth is aspirated, bronchoscopy has to be done for retrieval of tooth [18].

*Injury to Temporomandibular Joint*: It is mainly due to the application of excessive forces while extracting mandibular teeth and failure to support mandible. It can be avoided by using mouth gags and supporting mandible properly. Unsupported mandible may lead to dislocation of temporomandibular joint. If occurred, it must be reduced immediately by mechanical reduction.

#### **Table 13.10** Complications of exodontia



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**Fig. 13.29** Fractured alveolar process

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**Fig. 13.30** Fractured maxillary tuberosity

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**Fig. 13.31** Dry socket

#### *Hemorrhage*: It is classifed as


Mechanical reduction is done by an operator standing in front of the patient and holding the mandible with both hands. The thumbs should be placed over the external oblique ridge/ molars and the fngers holding the lower border of mandible. Once held frmly, mandible should be moved in inferior, posterior, and superior directions in a sequential manner [6].

*Oroantral Communication and Fistula*: Oroantral communication (OAC) is a pathologic communication between oral cavity and maxillary antrum; however, once epithelized, it is termed as oroantral fstula (OAF). OAC must be closed immediately if it is larger than 5 mm. In cases of OAF, fstulectomy followed by closure is the treatment of choice [19].

Refer the Chap. 24 on oroantral communication and fstula for further reading.

*Dry Socket*: Dry socket or alveolar osteitis denotes delayed healing with moderate to severe pain. Birn's, hypothesis is the most accepted explanation of dry socket. It states that trauma and infammation cause release of stable tissue activator from adjacent bony socket and soft tissue. Tissue activator converts plasminogen to plasmin which causes lysis of blood clot and pain. Management of dry socket involves relief of pain and ameliorating healing. A loose dressing composed of zinc oxide and oil of cloves on cotton wool is tucked into socket. Analgesic tablets and warm saline rinses are prescribed and patient is kept on regular follow-up [20, 21].

*Osteomyelitis*: It is 'an infection of the bone and the bone marrow which can be caused by an infection in the body spreading in the blood stream from point of origin to the bone'. Appropriate antibiotics for an extended period of time is the line of treatment. In chronic cases, surgical debridement becomes mandatory [22, 23].

#### **13.16 Technological Advances in Exodontia Techniques** [24]

Evolution never stops, this can be prominently justifed by the fact that a variety of new techniques and instruments have been introduced to revolutionize the feld of oral and maxillofacial surgery. Some of the technological advancements for dental extraction are highlighted here.

#### **13.16.1 Powered Periotome**

It is an electric unit which contains a controller box with adjustable power settings and a periotome mounted on a handpiece that is activated by a foot control. Use of standard periotome is cumbersome as the force delivered is uncontrolled; however, this powered periotome is characterized by complete control over the force delivery and the depth to which it travels into the periodontal ligament space.

This device functions by wedging and severing mechanisms. The thin metal blade of periotome is wedged into the periodontal ligament space in a circumferential manner severing the Sharpey's fbers. Once most of the Sharpey's fbers are severed, tooth can be extracted with minimal lateral movement. Hence, it allows fapless removal of tooth maintaining the periosteal blood supply with reduced risk of fracture of buccal or lingual cortical plate and decreased postoperative pain and discomfort.

#### **13.16.2 Physics Forceps** (Fig. 13.32)

Golden–Misch [25, 26] based on Class I lever mechanics designed the Physics Forceps to perform exodontia atraumatically. These forceps have a bumper which acts as a fulcrum, is placed at the mucogingival junction on the facial aspect applying steady, unrelenting pressure. Other than the bumper, there is a lingual beak, which is positioned on lingual or palatal root, making a single point contact with the tooth.

Due to the pressure applied by the bumper, periodontal ligament is traumatized resulting in the release of hyaluronidase. Once the enough chemical breakdown of periodontal ligament is achieved by the hyaluronidase, the tooth is released from its attachment to the alveolus aiding in easy removal. Physics forceps releases more hyaluronidase than conventional forceps in a shorter period of time, resulting in more effcient extraction of tooth with minimal trauma to the alveolar bone.

#### **13.16.3 Use of Implant Drills for Extraction Prior to Implant Placement**

Yalcin and colleagues [27] suggested a novel and minimally invasive technique to perform exodontia with minimal risk of damaging the thin buccal bone. The implant's drills were inserted into the root canals making the roots walls thin leading to extraction with application of much less force.

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**Fig. 13.32** Physics forceps

#### **13.16.4 Use of LASER**

Laser offers a noncontact and low vibration bone cutting without any visible, negative, and thermal side effects. Er:YAG laser can be used for surgical extractions to ablate the covering bone layer by layer exposing the portion of the root. Once the tooth/root is uncovered, they can be conventionally removed [28]. However, laser osteotomies are time consuming and require constant suctioning to achieve a dry feld for effective cutting.

#### **13.16.5 Piezo Surgery**

Piezo surgery is very effective in bone cutting as it works selectively without injuring any soft tissue structure. Hence, it is very advantageous over the conventional burs which have potential to cause injury to soft tissue. Also, a clearer feld is obtained while using piezo surgery. However, the time required while using piezo surgery is more [29].

#### **13.17 CASE Scenario**

#### **CASE 1 [18, 30]**

Patient is subjected to an extraction of a tooth and during the procedure, the extracted tooth is lost leaving an empty alveolar socket. The tooth is nowhere to be seen in the oral cavity neither it could be found in the surrounding area.

Possibilities:


Clinical Features:

• *Aspiration.*

Signs and symptom of aspiration depends on the site where the tooth is present. A laryngotracheal obstruction presents with dyspnea, cough, and stridor. It also results in diffculty in breathing with or without cyanosis. Chocking is also characterized by the sign of hands clutched to the throat, depending on whether the chocking is partial or complete. However, tooth in bronchus is associated with cough, diminished airway entry, dyspnea, and wheezing. Sometimes, the patient may remain asymptomatic for several months if the aspirated tooth is very small. However, long-term retention may result in late complications including postobstructive pneumonia, atelectasis, bronchiectasis, pneumothorax, hemorrhage, lung abscess, vocal cord paralysis, and death.

• *Ingestion.*

Generally, the passage of ingested tooth through the gastrointestinal tract is uneventful. In cases of obstruction, the most frequently noticed symptoms are dysphagia and odynophagia. Esophageal obstruction presents with gagging, coughing, chest pain, drooling of saliva, nausea, hematemesis, regurgitation, muscular incoordination, and incessant twitching. Abdominal pain is one of the symptoms other than fever, nausea, vomiting, and abdominal distensions in cases of abdominal impactions.

Management:


#### **CASE 2** [31]

A 33 year-old male reported with a chief complaint of a frm, diffuse swelling of size approximately 2 × 1 cm in left mandibular body region with occasional pus discharge from the extraoral skin fstula (Fig. 13.33a). He also complained of associated intermittent pain and fever.

#### **History**

On further questioning, he revealed that he had visited a private clinic 6 months back for the complaint of dental caries. Following clinical and radiographic examination, the dentist had planned to extract the tooth. To the patient's knowledge, the extraction was done uneventfully, but one root was lost during the procedure. Patient was prescribed with antibiotics and analgesics for a period of 5 days. The patient became apprehensive and uneasy in the following days. The fear of further complications kept him from visiting the dentist again and the condition went on worsening. Finally, after 6 months, he reported to an oral and maxillofacial surgeon.

#### **Investigations**

An orthopantomogram was taken which revealed a displaced root fragment in left frst molar region. (Fig. 13.33b).

#### **Diagnosis**

Displacement of Mandibular molar root in buccal space.

#### **Management**

After obtaining patient's consent, under antibiotic coverage and local anesthesia, surgical exploration was done through the existing skin fstula extraorally. With the digital pressure, the root piece was delivered out (Fig. 13.33c). Curettage and debridement was done carefully and patient was kept on follow-up. Closure was not performed. Antibiotics, analgesic, and nonsteroidal anti-infammatory drugs were prescribed postoperatively. Patient recovered without further incident. In the late period of follow-up, no complication was observed except extraoral scarring.

296

**Fig. 13.33** (**a**) Patient with extraoral swelling and skin fstula. (**b**) Orthopantomogram showing displacement of left frst mandibular molar root into adjacent space. (**c**) Retrieval of root from buccal space

#### **References**


removal of mandibular third molar: a single-blind randomized clinical trial. J Oral Maxillofac Surg. 2013 Sep;71(9):1484–9.


#### **Articles for Additional Reading**


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## **Management of Impacted Third Molars**

George Varghese

#### **14.1 Introduction**

Even as the scope of practicing oral and maxillofacial surgery grows and continues to evolve, the mainstay of practice remains dentoalveolar surgery. In this area, the surgical removal of impacted teeth is one of the commonest procedures that is performed. Among the teeth that are commonly impacted, the mandibular molars rank frst, followed by the maxillary third molars and the maxillary canines. Less commonly, impaction of other teeth such as the mandibular canines, maxillary and mandibular premolars, and the second molars are also seen.

#### **14.1.1 Terminology**

The term impaction comes from the term "impactus," which is of Latin origin. Its general usage refers to the failure of an organ or structure in achieving its normal position because of an abnormal mechanical condition.

Archer [1] defned impacted tooth as a tooth that is partially or completely unerupted and is positioned against another tooth or bone or soft tissue so that its further eruption is unlikely.

Lytle [2] proposed a defnition that is intimately related to that of Archer. An impacted tooth is a tooth that has failed to erupt into its normal functional position beyond the time usually expected for such appearance. Eruption may have been prevented by adjacent hard or soft tissue including tooth, bone, or dense soft tissue.

G. Varghese (\*)

Andreasen et al. [3] defned impaction as a cessation of the eruption of a tooth caused by a clinically or radiographically detectable physical impediment in the eruption path or by an ectopic position of the tooth.


### **14.1.2 Incidence of Impaction**

*Archer observed that the following types of teeth, in order of frequency, are most likely to be impacted:* maxillary third molars, mandibular third molars, maxillary cuspids, mandibular bicuspids, mandibular cuspids, maxillary bicuspids, maxillary central incisors, maxillary lateral incisors.

**14**

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 299

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_14

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_14) contains supplementary material, which is available to authorized users.

Principal, Professor and Head, Department of Oral and Maxillofacial Surgery, Pushpagiri College of Dental Sciences, Tiruvalla, Kerala, India

#### **14.2 Management Techniques for the Impacted Tooth**

Although the standard management strategy is usually considered to be surgical removal of the impacted tooth, the following methods listed below also should be considered depending upon the case:


#### **14.2.1 Controversies on Prophylactic Removal of Third Molars**

The benefts of prophylactic surgical removal of impacted third molars that are disease-free is quite controversial [4–6]. There are opinions that retaining the teeth may be more costeffective than prophylactic removal, at least in the short to medium term. Nevertheless, there may still be clinical situations that demand prophylactic surgery. Each clinical scenario needs an individualized evaluation and the consequences of all management techniques must be discussed with the patient. Thomas Dodson in [4] brought out a classifcation based upon the presence/absence of symptoms and the presence/absence of disease. He proposed to use this method to decide on the removal vs retention of third molars.

### **14.3 Etiology of Impaction**

Generally, the third molars or the wisdom teeth are the last teeth to erupt and they erupt between 18 and 25 years of age. Since they erupt at about the time when the youth goes off into the world to become "wise," the name "wisdom teeth" was used.

A number of theories have been put forth to explain the phenomenon of impaction. The following are the most commonly accepted ones:-


Berger [7] listed the following local causes for impaction of teeth:


Impaction may also be found with no local predisposing conditions cited above.

According to Berger, the following are the systemic causes of impaction:


#### **14.4 Indications for Removal**

Despite the fact not all unerupted/impacted teeth cause problems, all have that potential. Based on extensive clinical studies, indications for removal have been identifed.

1. *Pericoronitis and Pericoronal abscess* (Fig. 14.1a, b, c)—This is the most common cause for extraction of mandibular third molars (25–30%). Pericoronitis is frequently found to be associated with distoangular and

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.1** (**a**, **b**, **c**) Impacted right mandibular third molar with pericoronitis causing extraoral abscess (**a**) Extraoral abscess (Yellow arrow), (**b**) Impacted 48 with pericoronitis (yellow arrow), (**c**) OPG showing impacted 48 (Yellow circle)

vertical impaction. If treated inadequately, the infection may extent posteriorly resulting in submasseteric abscess.

	- (a) *Crowding of incisors:* Third molars has the potential to generate force in an anterior direction, which in turn can cause mandibular incisor crowding. Hence, removal of third molars has been recommended during or after orthodontic treatment. The hypothesis that the mesial pressure from the third molars is transferred through the contact points resulting in the narrow contacts of the lower incisors is slipping. Contemporary studies have questioned this hypothesis. However, it is still believed by certain clinicians, and third molars may be removed for these reasons.
	- (b) *To facilitate orthodontic treatment*—Since the recent trends in orthodontics prefer non-extraction modalities of treatment, distalization of molars has become ever more popular, particularly with regard to Class II malocclusions. In such cases, in order to expedite the distal movement of maxillary molars, the impacted or erupted maxillary third molar tooth may be extracted.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.2** IOPA X-ray of Horizontally impacted tooth 38 with dental caries

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**Fig. 14.3** Horizontal impaction of 48 causing bone loss (yellow arrow) distal to 47

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**Fig. 14.4** OPG showing impacted 38 associated with dentigerous cyst of mandible involving the left ramus, angle, and body


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.5** OPG showing impacted left mandibular third molar in inverted position associated with supernumerary (red circle) with fracture of left angle mandible (yellow arrow). Note multiple impacted supernumeraries (yellow circles) and fracture of right condyle (red arrow)


#### **14.4.1 Relative Contraindications for Removal of Impacted Tooth**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.6** Coronal section of mandible in the region of the third molar showing a thick buccal alveolar bone and a thin lingual plate

functional position. The third molar may also serve as a bridge abutment. Such cases require multidisciplinary evaluation with the prosthodontist and endodontist.

5. *Deeply impacted third molars* which do not appear to be associated with local or systemic pathology must not be removed.

#### **14.5 Surgical Anatomy**

The mandible comprises of a body which is horseshoe shaped and has the ramus on either side, which are fat and broad rami. Each ramus has two processes at the superior end—the coronoid process, which is more anterior, and condylar process, which is continuous with the posterior border.

The mandibular third molar tooth is usually present at the distal end of the mandibular body, which adjoins a thin ramus. The body-ramus junction is a weak area that can fracture if excessive force is employed during the elevation of the third molar. The tooth lies between the buccal cortical plate, which is thick, and the thin lingual cortical plate (Fig. 14.6). In most instances, the thickness of the lingual plate may be less than 1 mm, and the tooth may get displaced into the lingual pouch if untoward force is applied.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.7** Radiograph showing the proximity of impacted third molar roots to the mandibular canal

#### **14.5.1 Neurovascular Bundle**

The mandibular canal lies beside or below the third molar roots. Usually, the canal lies slightly buccal and apical to the third molar roots, but this varies frequently (Fig. 14.7). The canal contains the inferior alveolar neurovascular bundle including the artery, vein, and nerve within a sheath of fascia. The third molar roots may sometimes be indented by the canal, but actual penetration is rare. In these cases, attempting to elevate fractured root tips may result in the displacement of the tips into the mandibular canal. If the canal vessels get injured by instruments or forceful intrusion of the tooth roots, profuse hemorrhage may result.

#### **14.5.2 Retromolar Triangle**

This is a depressed roughened area behind the third molar bounded by the buccal and lingual alveolar ridge crests. The retromolar fossa is a shallow depression that occurs just lateral to the retromolar triangle. Mandibular vessel branches may emerge at the fossa or triangle and can be injured during surgical exposure of the third molar region if the incision is not taken laterally. This can result in brisk hemorrhage (Fig. 14.8).

#### **14.5.3 Facial Artery and Vein**

The facial artery and anterior facial vein are related to the mandibular body, anterior to the masseter muscle, where they cross the inferior border of the mandible. They lie below the second and third molar teeth and may be injured when a buccal incision is placed at an inferior level. To avoid this, it is best to start the incision at the sulcus depth and move upward toward the tooth.

**Fig. 14.8** Schematic diagram showing the retromolar vessel emerging through retromolar foramen

The lingual nerve often runs below and behind the third molar, and contacts the periosteum over the lingual cortex at a sublingual level. Cardinal anatomic studies have shown the close relation of the lingual nerve to the lower third molar region [8, 9].

The lingual nerve usually lies 2.3 mm below the lingual alveolar crest, and 0.6 mm medial to the mandible, when viewed from a frontal plane.

Since the lingual nerve is close to the third molar, it is at risk of damage during surgical removal of the tooth. This may lead to anesthesia of the tongue in its anterior twothirds, and also loss of taste sensation in this area.

The surgeon should also be aware of the course and direction of the mylohyoid and long buccal nerve to prevent inadvertent injuries to these nerves (Fig. 14.9).

#### **14.5.5 Bone Trajectories of Mandible**

The bone trajectories of the mandible, referred to as grains, course in a longitudinal direction. Even though the technique of chisel and mallet has almost become obsolete, it is important to know the bone trajectories. On the buccal side, a horizontal chisel cut that is oriented parallel to the superior border may cause extensive splitting till the frst molar region due to the grain direction. To prevent this, the operator must make a "vertical stop cut" (Fig. 14.10), with the bevel ori-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.11** Whole tooth displaced into lingual pouch beneath the mylohyoid muscle

ented posteriorly, just distal to the second molar. The chisel must be angulated correctly at all times to avoid fracture of mandible distal to the third molar.

#### **14.5.6 Lingual Plate**

Since the lingual pate is very thin, it may be perforated by the apices of lower third molar roots. If the roots are fractured, attempting to elevate may cause them to be displaced into the "lingual pouch," from where it will be diffcult to retrieve. The entire tooth also may rarely be pushed into the lingual pouch (Fig. 14.11).

### **14.6 Classifcation of Impacted Mandibular Third Molar**

To assess surgical diffculty, several classifcations have been proposed, which can help formulate a treatment plan that is effcient and has minimum morbidity. Either the periapical radiograph or the Orthopantomogram is used to analyze the impacted tooth for its classifcation.

The most commonly used are:-

1. *Angulation* [10] of the impacted tooth (Fig. 14.12) (George Winter classifcation).

Vertical, Mesioangular, Horizontal, Distoangular,

Buccoangular,

Linguoangular,

Inverted,

2. *Relationship* between the impacted tooth and the *anterior ramal border* [11]—This assesses the amount of space present between the anterior border of the ramus and the distal wall of the second molar. This indicates the effective space available for the tooth to erupt (Fig. 14.13).

*Class I*—There is enough mesiodistal space between the anterior border of ramus and second molar to accommodate the third molar.

*Class II*—Space between anterior border of the ramus and second molar is less than the mesiodistal width of the crown of the third molar.

*Class III*—No mesiodistal space available and the third molar is almost completely within the ramus.

Class III impactions present greater diffculty in removal.

3. *Depth of the impacted tooth* and tissue type that overlies the tooth (Pell and Gregory Classifcation based on occlusal level of the tooth)—i.e. soft tissue, partial bony, or complete bony impaction (Fig. 14.14).

*Position A*—The highest point of the tooth is at the same level of the occlusal plane or above it.

*Position B*—The highest point of the tooth is above the cervical line of the second molar but below the occlusal plane.

*Position C*—The highest point of the tooth is well below the cervical line of the second molar (Figs. 14.15 and 14.16).

	- (a) Erupted.
	- (b) Partially erupted.
	- (c) Unerupted.

Unusual

**Fig. 14.12** Classifcation based on angulation of tooth (Winter's classifcation)

**Fig. 14.13** Pell and Gregory Classifcation based on relationship to the anterior border of ramus

**Fig. 14.14** Pell and Gregory Classifcation based on relationship to the occlusal plane of the impacted tooth to that of the second molar

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.15** Examples of impaction showing combination of angulation of tooth, relationship to anterior border of ramus and depth of impaction. (**a**) Mesioangular impaction in Class I ramus relation and Position

A depth—an impacted tooth easy for removal. (**b**) Distoangular impaction in Class III ramus relation and Position B depth—an impacted tooth diffcult for removal

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.16** OPG showing impacted mandibular third molar displaying only crown of the tooth with no roots visible (yellow arrow) with close proximity to inferior alveolar canal in a 52-year-old male. Surgical removal of 38 was attempted without taking CT or CBCT. During surgery, there was accidental fracture of left angle for which internal fxation has to be done. Note impacted 18 and 28

#### **14.7 Preoperative Planning**

Presence of an impacted third molar must be diagnosed systematically using the patient's chief complaint and history, clinical examination, and appropriate investigations.

The impacted third molar must be evaluated both clinically and radiographically prior to surgery for successful and speedy removal. Ideally, a periapical radiograph must be taken and an OPG must be added if the intraoral radiograph does not provide enough information about the tooth or adjacent structures.

Manuel et al. has [12] developed a simple format for evaluation of third molar impactions.

This comprehensive format is ideal for residents in oral surgery during their learning years. Using this format, third molar impactions may be analyzed, and diffculty level may be assessed and anticipated. Residents can judge problems that they may encounter during the procedure and can evaluate the patient better postoperatively.

#### **14.7.1 Clinical Examination**

This includes taking the patient's history, clinical examination extraorally and intraorally.

1. *History taking*

*Complaints of the patient*—Impacted teeth are usually asymptomatic and patients are aware of their existence only when told by the dental practitioner. Symptoms, if any, are usually due to acute or chronic pericoronitis, or due to acute pulpitis secondary to dental caries.

2. *Extraoral examination*

The clinician must examine the face and neck for redness and swelling related to infection. The lower lip is tested for anesthesia or paresthesia. The regional lymph nodes must be assessed by palpation for any tenderness or enlargement.

	- (a) Mouth opening—The ability of the patient to open the mouth is analyzed, and any trismus, fbrosis, or hypermobility of the joint is noted. The size of the mouth (microsomia/macrosomia) is also checked. Third molar access may be restricted if the mandible is retrognathic, while a prognathic mandible offers good access.
	- (b) General examination of oral cavity- oral mucosa, teeth, and oral hygiene.
	- (c) Examination of the third molar area for signs of pericoronitis and state of eruption of the tooth.
	- (d) Condition of the impacted tooth- presence of caries, dental fllings, and internal resorption (which may resemble caries). The angle of the tooth and locking beneath second molar must be noted and confrmed with appropriate radiographs.
	- (e) Condition of frst and second molars—presence of caries, fllings, or crowns; root canal treatment may put the second molar at risk of fracture and the patient must be warned of this. Distal periodontal pocketing, root resorption, and absence of the second molar must also be noted.
	- (f) Space present between the second molar distal surface and the ascending ramus: A small distance makes access diffcult, and a large distance makes the tooth more accessible. For maxillary teeth, the distance between the second molar and tuberosity must be considered. Access can also be decreased by distal tilting of second molar.
	- (g) Adjacent bone may develop infection, which can spread along the mesial surface of the tooth and affect the second molar, which would then require extraction. Infection/osteomyelitis can spread to the ramus in the case of distoangular impacted third molars, through recurrent submasseteric abscesses in this region.
	- (h) Systemic skeletal diseases may cause pathological complications which should be noted. For instance, conditions such as osteogenesis imperfecta and osteosclerosis may cause fractures during the procedure. In acromegaly, the mandibular bone is massive which makes the procedure diffcult because the mandible consists of massive bone. In Paget's disease also tooth removal is diffcult as the bone is affected by resorption and repair.

(i) Presence of cysts and tumors—The impacted tooth may be associated with eruption cysts or large odontogenic cysts can occur in relation to impacted tooth. By and large, they cause displacement of the tooth. Benign and malignant tumors such as ameloblastoma may also be found involving the tooth. Odontomes may also be present in relation to the third molar.

#### **14.7.2 Radiography of Impacted Mandibular Third Molar**

Any factor that increases the diffculty of third molar removal can be analyzed from the preoperative radiograph.

The following radiographs may be used for analysis:


An essential criterion for a good flm is that the buccal and lingual cusps of the second molar must be superimposed on each other in the same vertical and horizontal plane. This appearance of the second molar is referred to as 'enamel cap'.

	- When periapical X-ray cannot be taken due to trismus or retching.
	- To provide supplementary information like height of mandible in the region of the third molar, or bone height beneath a deeply buried tooth. The latter is useful to assess the risk of pathological fracture in thin mandible, or in cases of cysts or tumors.

Since the introduction of OPG, the use of lateral oblique view is limited and is only considered when an OPG is unavailable.

3. *Orthopantomogram (OPG):* This provides the same information as the lateral oblique view, with less distortion. The OPG is now used routinely to precisely the locate impacted teeth.

#### **14.7.2.1 Interpretation of Periapical X-ray**

The following points must be noted in the periapical radiograph:-


The frst line or "white" line extends across the occlusal cusp tips of the erupted mandibular molars and is drawn distally over the third molar region. This line indicates the axial inclination of the impacted tooth. For example, the white line is parallel to the occlusal surface of the third molar if the tooth is vertically impacted, whereas, the "white" line converges with the occlusal surface in front of the tooth in distoangular impactions.

The "white" line also indicates the depth of the tooth as compared to the erupted second molar.

The second "amber" line extends from the bone surface distal to the third molar and is drawn to the interdental septum crest between the frst and second molar. When drawing this line, it must be clearly differentiated from the external oblique ridge shadow, which can lie above and in front of the posterior end of the "amber" line. The posterior end is the shadow cast by the bone in the retromolar fossa and not the external oblique ridge. The "amber" line shows the margin of the alveolar bone enclosing the tooth. Hence, when soft tissues are refected, the portion of the visible tooth will be the part that was lying above and in front of the "amber" line in the radiograph. The rest of the tooth will be covered by bone.

The third line or "red" line assesses how deep the impacted tooth is within the mandible. This is drawn by dropping a perpendicular from the "amber" line to the point at which the elevator will be applied to elevate the tooth (an imaginary point). This point usually lies on

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.17** (**a**) White, amber, and red lines (Winter's WAR lines) marked in the periapical X-ray. (**b**) WAR lines drawn on a distoangularly impacted mandibular third molar. Note that in distoangular impac-

the mesial surface of the impacted tooth, at the cementoenamel junction, except in the case of distoangular impactions. The longer the red line, the more deep the tooth is impacted, and the surgical procedure will be more diffcult.

(c) *Root pattern of impacted tooth*—The number, shape, and curvature of roots are noted. Hypercementosis is noted if present. If the root apex takes a sharp bend toward the X-ray beam, it may appear blunt and short on the image. This fnding should therefore be investigated in more detail.

The type of root morphology dictates the diffculty of the surgical procedure. If root development is limited, it can result in a "rolling" tooth, which is challenging to remove.

(d) *Shape of crown*—If the tooth has prominent cusps, or large, square crowns, the diffculty increases as compared to small crowns and fat cusps. The size and shape of the crown of third molar is particularly important with regard to the "line of withdrawal." Sometimes, the path of crown removal can be obstructed by the second molar crown (Fig. 14.18).

In these cases, the cusp of the third molar appears to be superimposed on the distal surface of the second molar in the radiograph. If elevation is attempted by applying force on the mesial surface of the impacted tooth, the second molar may get displaced from the socket, and there is a risk of mandible fracture. The risk is especially high for second molars with conical roots. In such cases, sectioning the third molar is advisable.

(e) *Texture of the investing bone*—As age advances, the bone undergoes sclerosis and becomes less elastic. The bone texture can be analyzed by visualizing the size of the cancellous spaces and the bone density. Bone that tions, the perpendicular "red" line should be dropped to the cementoenamel junction on the distal side of the impacted tooth and not on the mesial side as in other angulations

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**Fig. 14.18** "Locking of the crown" of impacted third molar by the second molar. Note that the cusp of third molar is superimposed upon the distal surface of second molar

has large spaces and fne structure is generally elastic. On the contrary, sclerotic bone has small spaces and dense bone structure. Dense bone does not expand easily during luxation and more bone removal may be required.

	- 1. If there is a band of reduced radio-opacity that crosses the roots, and this band coincides with the outline of

the inferior alveolar canal, this is a sign that the tooth root may be grooved by the canal. This sign refects the lesser amount of tooth structure lying between the X-ray source and the flm.


The following signs have been demonstrated to be associated with a signifcantly increased risk of nerve injury during third molar surgery: (Fig. 14.19a, b, c)


In the presence of any of the above fndings, great care should be taken in surgical exploration and the decision to treat is carefully reviewed. If on the initial panoramic radiograph there is an evidence of a close relationship between the roots of the lower third molar and the IAC, a second radiograph should be taken using different projection geometry.

If the third molar is found to be in close relationship with the inferior alveolar canal, the patient should be informed in advance regarding the likelihood of impairment of labial sensation following the surgical removal of the tooth. This should be recorded in the case record and in the consent form. In such cases, authors have recommended coronectomy (partial tooth removal, intentional root retention, partial odontectomy) as an option. However, this technique cannot be considered foolproof and long-term studies are required to know the success of coronectomies [15, 16]

(g) *Position, root pattern, and nature of crown of second molar.*

The space between the distal surface of the second molar and the mesial surface of the impacted third molar has an effect on the ease of removal of the third molar. The closer the third molar is to the second molar, the more challenging the surgery becomes. If the long axis of the second molar is tilted distally, it is more diffcult to remove.

*Cone beam computed tomography* (CBCT) (Fig. 14.20a, b, c) CBCT is now available for dental use and offers low dose imaging in multiple planes.

Using this modality, accurate three-dimensional imaging can be done to determine the relationship between the roots of the third molar and the inferior alveolar nerve (IAN). The recent recommendation is that when the OPG suggests a close relationship between the roots of the lower third molar and IAN, cone beam CT scanning should be advised [17–19]. The effective dose from CBCT is comparatively less than the conventional CT scan and also at a lower expense.

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**Fig. 14.19** (**a**–**c**) Radiographic relationship of third molar root to inferior alveolar nerve (**a**) Cortical outline of the canal is intact. This probably represents superimposition only. (**b**) There is loss of cortical outline of the nerve canal. The nerve may be grooving the tooth. (**c**) There is loss of cortical outline as well as narrowing and deviation of the nerve canal, denoting an intimate relationship of the nerve with the tooth and possibly perforation of the tooth roots by the nerve

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.20** (**a**) CBCT Panoramic view showing the relationship of 38 and 48 to the inferior alveolar canal (IAC) [red line]. The changing relationship of the IAC to 48 can be noted in (**b**–**d)**. Relationship of IAC

#### (yellow arrow) at coronal level (**b**), at cervical level (**c**), and at apical one third level (**d**)

#### **14.7.3 Lingual Nerve Protection and Injury**

Locating the lingual nerve clinically and by imaging is more challenging. Lingual nerve injury although less common than inferior alveolar nerve (IAN) injury is often more unbearable to the patient. Patients fnd it diffcult to tolerate lingual nerve damage, including loss of taste and sensation of tongue, as compared to IAN damage. Unlike the IAN, the lingual nerve is not usually imaged prior to third molar surgery. In cases where distal, distolingual, and lingual bone is to be removed, technique of raising the lingual fap and protecting the lingual nerve by a broad smooth lingual fap retractor in a subperiosteal plane has been advocated by certain authors and this technique is followed in certain parts of the world. Again, there are conficting reports where the lingual fap retraction itself has caused an increase incidence of lingual nerve paresthesia [8, 20–22].

*The incidence of IAN involvement 1–7 days after surgery is around 1–5% and the incidence of lingual nerve involvement one day after surgery (excluding the use of lingual fap elevation) varies from 0.4 to 1.5%* [23, 24].

#### **14.7.4 Preoperative Evaluation of Difculty of Removal**

Various techniques have been suggested for the preoperative evaluation of diffculty, but these have often been of limited value. Pederson [25] recommended a scale to evaluate the diffculty index.

Although the Pederson scale can be used for predicting operative diffculty, it is not extensively used [26] because it does not take various other relevant factors into account, such as bone density, fexibility of the cheek, and mouth opening.

Surgical removal impacted third molar becomes diffcult with the following factors:-


Surgical removal of impacted teeth may be easier in younger patients because of incompletely formed roots, large follicular space, incompletely formed roots separated from inferior alveolar canal, and greater elasticity of bone. In young patients, the bone texture is usually soft and resilient, but in older adults, the bone becomes progressively more dense, hard, and brittle. Therefore, the extraction of a partially erupted/impacted tooth in an elderly adult with sclerotic bone may cause great diffculty. While a tooth with adverse root morphology in soft, resilient bone of a young adult can be elevated expeditiously.

*To summarize, the diffculty of the surgical procedure is dictated by 3 major factors:- (1) Depth of impaction (2) Type of overlying tissues, and (3) Age of the patient.*

As a general rule, the more diffcult and time-consuming the surgical procedure is, the more diffcult and protracted is the postoperative recovery period.

#### **14.8 Operative Procedure**

Any standard operative plan consists of the following stages:-


#### **14.8.1 Incision and Designing the Flap**

Envelope fap, which is commonly used, extends from the posterior margin of the impacted tooth, and runs forward till the level of the frst molar. The posterior end of the incision is directed buccally along the external oblique ridge (Fig. 14.21a, b).

If greater access is required, the envelope fap will not be adequate. In such cases, a release incision is given on the anterior-most point of the incision, which creates a triangular fap (Fig. 14.22a, b). This incision must begin at a point that lies approximately 6 mm below the gingival margin in the buccal sulcus and then extend upward in an oblique fashion to the gingival margin. The incision ends on the margin at a point between posterior and middle thirds of the second molar.

The envelope incision has been associated with fewer complications, and healing occurs faster as compared to the triangular fap. A small artery, the buccal artery, may sometimes be encountered while placing the releasing incision, and mild bleeding can result if this is injured. If more exposure is needed, the vertical release incision can be brought forward, and placed between the second and frst molar as shown in the Fig. 14.23a, b.

The incision is then continued along the cervical line of the second molar and reaches the middle of its posterior border. The incision continues in a posterior and lateral direction, along the anterior border of the ramus, depending on the exposure required. It is essential that this arm of the incision is oriented laterally, and not in a straight line, because the mandible diverges laterally. If the incision is extended straight, the knife may cause lingual nerve damage. The lateral extension will also preserve small vessels that emerge from retromolar fossa (Fig. 14.24).

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.22** (**a**, **b**) Standard triangular fap with a release incision in the anterior aspect

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.23** (**a**, **b**) Where more exposure is needed, the vertical release of the triangular fap is placed between the second and frst molar

**Fig. 14.24** (**a**) Classical Terrence Ward's incision, (**b**) Modifed ward's incision

The mucoperiosteal fap is then refected laterally with a periosteal elevator. An Austin's retractor (third molar retractor) is used to hold the fap in position. The "Minnesota retractor" may also be used to hold the fap. This retractor must be placed just lateral to the external oblique ridge. Stability is achieved by resting against the lateral surface of the mandible. While holding the retractor, fngers must rest at its distal end so that the retractor can be moved laterally without blocking the vision of the operator.

The literature shows various fap designs with modifcations for lower third molar impactions with each claiming its own merits [27, 28]. However, for the majority of the cases, the conventional fap designs will serve the purpose.

#### **14.8.2 Bone Removal**

After fap refection, the next step is bone removal from around the impacted tooth. The amount of bone to be removed will depend on the depth of impaction. This can be done either by use of bur/rotary instruments or by chisel and mallet or ultrasonic devices/peizo surgery [29, 30] or laser devices [31]. The method used may depend on individual preference. Suffcient amount of bone must be removed, both to free the tooth from obstruction and to provide a point of application for the elevator.

The buccal cortex plays an important role in maintaining the strength of the mandible. Hence, the removal of buccal bone should be minimized, in order to prevent weakening and fracture of the mandible. The bone buccal to and distal to the impacted tooth must be removed until the cervical line of the tooth. Beyond this, bone removal must be done judiciously, in such a way that the strength of mandible is not affected, but, at the same time, the effciency of surgery is maintained. To achieve this, a deep vertical gutter is drilled on the buccal side, and, if required on the distal side of the tooth. This "guttering method" maintains the buccal plate height, does not weaken the mandible, and at the same time, creates adequate space around the tooth to permit its free movement (Fig. 14.25).

The "Postage stamp" method of bone removal used in transalveolar extractions can also be used to remove the buccal bone, but this method may be more time-consuming. The surgical removal of an impacted tooth is basically a transalveolar extraction and all the basic principles, right from the mucoperiosteal fap design to bone removal and closure has to be followed religiously to achieve good healing.

Bone can also be removed from the mesial aspect of the impacted tooth using this method. In this region, bone removal must be extremely conservative to avoid damage to the distal aspect of the adjacent second molar. Extreme

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.25** "Guttering method"- A deep vertical gutter using bur is made alongside the buccal aspect and if required on the distal aspect of the tooth

care is taken while removing bone on the distolingual aspect, and proper retraction must be used to prevent lingual nerve damage from the bur. Due to the likelihood of damage to the lingual nerve, bone must not be removed on the lingual aspect. The commonly used burs for bone removal are the #8 round bur and a #703 fssure bur, although a wide variety may be used based on individual preference.

After the tooth is exposed, a point of application is created for the elevator. This allows the tooth to be displaced using only moderate force. If the tooth is resistant, further bone removal or tooth sectioning must be considered.

#### **14.8.3 Elevation of Tooth from the Socket**

Once bone removal is complete, tooth elevation can be attempted. Undue force should not be used for this purpose. Applying inappropriate amount of force, especially without suffcient bone removal, can cause the tooth to fracture, or can even cause fracture of the mandible. Because of the above risk, the use of instruments with high mechanical effciency is contraindicated for third molar removal. These instruments include dental extraction forceps and cross bar elevators. Once the obstructing bone has been removed, only a small amount of force alone is needed to deliver the tooth. Elevators such as the Warwick James elevator (both straight and curved types) and Coupland elevator, which have lower mechanical effciency, may be used for this purpose.

#### **14.8.4 Sectioning and Tooth Delivery**

If the tooth has been suffciently exposed but is still resistant to moderate force, tooth sectioning must be considered. The tooth is sectioned into appropriate pieces for easy delivery from the socket. Sectioning of the tooth not only avoids additional bone removal, but it also reduces operating time. Tooth sectioning can be carried out using a bur, which is preferred, or a chisel. In the standard technique, sectioning is carried out using the bur at the neck of the tooth, which facilitates crown removal frst, followed by the roots in a single piece. Alternatively, the tooth may be divided horizontally also. Nevertheless, in cases of divergent roots, or where the path of withdrawal is complex, the roots may have to be divided and removed separately.

The manner of sectioning of crown and root must be decided individually for each case and the standard technique need not be followed exactly (Fig. 14.26).

#### **14.8.5 Modifcations of standard technique**

Although the principles of third molar removal remain fundamentally the same, the angulation of the tooth may dictate certain modifcations. Angulation dictates the site of application of the elevator, as the path of withdrawal of the third molar should be along the line of least resistance. Therefore, the angulation, in terms of mesioangular, horizontal, vertical, and distoangular impactions must be considered.

The *mesioangular* impaction (Fig. 14.27a, b, c) (Video 14.1) is generally considered to be the least diffcult to remove. After elevating the mucoperiosteal fap and exposure of the crown, the buccal guttering is carried out till the mesial surface of impacted tooth, to a point below the cementoenamel junction. This allows the tip of the elevator to be introduced to engage beneath the cervical cementum on the mesial side of the tooth. When the elevator is rotated, the interdental bone is used as the fulcrum and the tooth rotates distally. Thus the tooth, which had an initial mesial angulation, now occupies a vertical position. When more force is applied using the elevator, the tooth is delivered. In some instances, although the tooth becomes vertical, further movement is prevented by the distal bone. This obstruction may be relieved by one of the following methods:

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.26** Possible damage to inferior alveolar neurovascular bundle if the bur is carried to the full width of the tooth inferiorly. Hence, bur is used to cut only three-fourth width of the tooth and the rest of the tooth is separated using a suitable instrument


Sometimes, the mesioangular tooth may be entrapped beneath the distal convexity of the crown of the second molar. In such cases, the tooth may be divided at the cervical region to separate the crown, which is then removed by applying force beneath its inferior surface. The roots may then be delivered by engaging at the bifurcation.

If the tooth roots are in close contact with the mandibular canal, applying levering force can force the root apex downward which may damage the neurovascular bundle. Crown sectioning must be preferred in such cases, which will allow the roots to be delivered upward away from the canal. This would prevent damage to the canal.

The *horizontally impacted* (Fig. 14.28a, b, c, d) (Video 14.2) tooth may need more bone to be removed as compared to mesioangular impaction. A deeply impacted tooth tends to engage either the crown or root of the second molar. This makes its removal diffcult. Adequate bone is removed superiorly to expose the entire crown width, as well as the upper third of the root. The point of application of elevator is pro-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.27** (**a**, **b**, **c**) (see text for details) Steps in the surgical removal of mesioangular impaction. (**a**) Bone removed up to cemento enamel junction using bur, (**b**) Sectioning of tooth, (**c**) Tooth delivery using elevator

cured below the mesiobuccal aspect of the impacted crown. The tooth is then sectioned at the cervical region and the crown is removed from the socket. The root is then brought forward into the vacant space previously occupied by the crown and it is then removed either in a single piece or after sectioning.

In cases where the impacted tooth is not locked beneath the distal convexity of the crown of the second molar and when an adequate amount of distal bone has been removed, it is possible to turn the tooth into a vertical position by application of force in the mesial aspect. This is similar to the procedure already described for the removal of mesioangular impactions. Use of further force with the elevator will expel the tooth out of the socket or force can be applied on the buccal side to remove the tooth.

Another method of removing horizontal impactions is to split the tooth horizontally into two by sectioning via the buccal groove into separate mesial and distal roots (technique shown in Fig. 14.29). The distal root with the attached crown part is elevated out frst followed by the deeply lying mesial root and part of the crown. If there is diffculty in elevating the deeply placed mesial root segment, it can be again sectioned into two at the cervical region and the crown and the root parts may be removed separately.

The *vertical impaction* (Fig. 14.29a, b, c) is one of the more diffcult ones to remove, especially if it is impacted very deeply. The procedure for bone removal and the sectioning is similar to that of a mesioangular impaction. Here also the bone is removed frst from the occlusal, buccal, and distal aspect. The distal half of the crown is then sectioned and removed, and the tooth is elevated by applying a small straight elevator at the mesial aspect of the cervical line. Alternatively, similar to mesioangular impactions, a pur-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.28** (**a**, **b**, **c**, **d**) Steps in the surgical removal of a horizontally impacted mandibular third molar. (**a**) Bone removal to expose the width of the crown and the upper third of the root, (**b**) Crown may be sectioned into two as shown in the fgure and elevated separately. Another technique is to divide the tooth at cemento enamel junction and elevate the crown as a single piece, (**c**) After removal of the crown, the distal

root sectioned at the furcation is brought forward into the space occupied by the crown, (**d**) Removal of the mesial root. (the technique shown in Fig. 14.29 can also be used for horizontal imapctions where the tooth is sectioned via the bifurcation and distal crown and root is elevated out frst, followed by the mesial crown and root)

chase point can be made on the buccal side of the tooth, and a Cryer's elevator may be used to deliver the tooth.

The *distoangular impaction* (Fig. 14.30a, b, c) is considered to be the most diffcult tooth to remove. The goal of the technique for removal of these teeth is to create an adequate buccal and distal trough (guttering) around the crown of the tooth to a depth below the cervical line. This will permit to make a point of application of elevator on the buccal aspect of the tooth. Then, using the buccal cortical plate as the fulcrum, force is applied to elevate the tooth out of the socket upward and distally. If some movement is obtained, the distal portion of the crown or the complete crown can be sectioned in a horizontal fashion from the roots and removed. It is preferable in this case to section the tooth segments further as needed rather than to remove more bone. It would be wise to remember the adage that "Tooth belongs to the surgeon and Bone belongs to the patient". This will ensure preservation of the structural integrity of the mandible. The roots are then delivered together or sectioned and delivered independently with a Cryer's elevator.

In cases where tooth sectioning is required, the distal root should be elevated frst followed by the mesial root.

#### **14.8.6 Debridement**

After tooth delivery, all bone debris and tissue must be removed from the socket. This is best accomplished by irrigation with saline and mechanically debriding the socket and the area under the fap with a cruet. A bone fle or a large bur is used to smooth any rough and sharp edges of the

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.29** (**a**, **b**, **c**) Steps in the surgical removal of a vertically impacted mandibular third molar. (**a**) Bone removal to expose the width of the crown, (**b**) Distal half of the crown sectioned up to the furcation

and it is removed along with the root, (**c**) Mesial half of the tooth is elevated by mesial application of force at the cervical line

bone. Any remaining dental follicle must be removed using a mosquito hemostat, to prevent cyst formation. An artery forceps may be used to remove fractured interdental septum or large pieces of bone. The socket and the wound margins (including under surface of mucoperiosteum) is irrigated with saline or sterile water to remove bone and tooth debris.

#### **14.8.7 Wound Closure**

Before attempting closure, bleeding from the socket is completely arrested. Further bleeding from the socket can be controlled using bone wax, Surgicel, or Gelfoam. If there is bleeding from the socket underneath a tight suture, blood will accumulate in surrounding tissue spaces leading to buccal or lingual hematoma or ecchymosis. The fap is then replaced to its original position and the initial suture placed just distal to the second molar. This suture reduces the possibility of the development of periodontal pocket distal to the second molar. The needle is passed from the buccal to the lingual side. Additional sutures are then placed as necessary. The sutures should be just tight enough to hold the fap. Over tightening should be avoided. The vertical component of the incision is left unsutured since it will act as a wound toilet.

Following the procedure, oral and written postoperative instructions given to patient and bystander ensure better patient compliance.

The infuence of lower third molar impactions on the periodontal health of the adjacent second molar and the infuence of third molar removal on the periodontal attachment of the second molar is a very contentious topic and multiple studies have been done in this regard [32].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.30** (**a**, **b**, **c**) Steps in the surgical removal of a distoangularly impacted mandibular third molar. (**a**) Bone removed to expose the full crown of the tooth to a depth below the cervical line, (**b**) Crown sectioned in a horizontal fashion from the roots and removed (some surgeons prefer to remove only the distal portion of the crown of third molar, so that a point of elevation is available distal to the second molar tooth), (**c**) Roots are then delivered together or sectioned and delivered independently with a Cryer's elevator

#### **14.8.8 Other Methods for Removal/Partial Removal of Impacted Lower Third Molar**

In addition to the standard surgical technique described above, there may be occasions where other methods of surgical removal also have to be considered. This is because no technique is suited to every case and it will be ideal to learn the different methods and choose the suitable one depending upon the case. Readers are advised to refer the concerned publications to get more details.

Some of the other methods seen in the literature are


#### **14.9 Impacted Maxillary Third Molar**  (Video 14.3)

Surgical management of upper third molars in general is less complicated compared to lower third molars. They cause less discomfort, are more likely to erupt and are simpler to remove unless unerupted and encased in bone. Removal of upper third molars results in far less postoperative morbidity.

The commonest type of impaction in maxillary third molar is vertical [42].

*Classifcation of impacted maxillary third molars*—The system of classifcation of impacted upper wisdom tooth is basically the same as that for mandibular third molar. However, there are some additional parameters to be considered which will aid in preoperative assessment of the case and guide in planning the surgery for a successful outcome.

	- (a) Fully erupted.
	- (b) Partially erupted.
	- (c) Unerupted:
		- within the bone
		- immediately beneath the soft tissues
	- (a) Vertical.
	- (b) Mesioangular.
	- (c) Distoangular.
	- (d) Laterally displaced with the crown facing the cheek, horizontal, inverted, and transverse positions.
	- (e) Aberrant position sometimes associated with pathological condition such as cyst.

Position B—Occlusal surface of the third molar is located between the occlusal plane and cervical line of the second molar.

Position C—Occlusal surface of the third molar is at or above the cervical line of the second molar.

	- (a) Sinus approximation (SA)—No bone or a thin partition of bone between the impacted maxillary third molar and maxillary sinus.
	- (b) No sinus approximation (NSA)—2 mm or more bone between the impacted maxillary third molar and maxillary sinus.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.31** Classifcation of impacted maxillary third molar based on angulation

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.32** Pell and Gregory classifcation based on relative depth of impacted maxillary third molar

	- (a) Fused (conical).
	- (b) Multiple—Favorable/Unfavorable.

#### **14.9.1 Radiographic Examination**

The following are the useful radiographs:


### **14.9.2 Indications for the Removal of Maxillary Third Molar**


#### **14.9.3 Adjacent Anatomical Factors to be Considered:** (Fig. 14.33a–d)


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.33** (**a**–**d**) Impacted third molars in a 75-year-old male. (**a**) OPG showing impacted 28, 38, and 48 with multiple root stumps and dental caries for 18. (**b**) Axial CBCT showing close relationship of 18

and 28 to maxillary sinus, (**c**) Sagittal view showing sinus approximation of roots of 27 and 28, (**d**) Sagittal view showing close relationship of 18 to sinus foor


#### **14.9.4 Surgical Removal of Impacted Maxillary Third Molar** (Figs. 14.35a–d and 14.36a, b)

The main diffculty here is that the coronoid process may block access to this region, which may be overcome by limiting the amount of mouth opening.

The procedure for maxillary third molar surgical removal is almost the same as that of the mandibular third molar.

#### **14.9.4.1 Incision**

It starts from the mesial aspect of the frst molar and extends distally beyond the distobuccal aspect of the second molar and is then continued into the tuberosity. In case of a deeply impacted tooth if greater access is required, a triangular fap may be raised by placing a release incision mesial to the second molar.

The mucoperiosteum is then refected using a Howarth's periosteal elevator, which may also be used to retract the fap.

#### **14.9.4.2 Removal of Overlying Bone**

Bone removal is generally limited to the occlusal and the buccal aspect of the tooth down to the cervical line to expose the entire crown (Figs. 14.35b and 14.36a). This is done using bur. To create space for the elevator to be inserted, more bone may be removed from the mesial part of the tooth, at a point above the maximum bulge of the crown.

Unlike mandibular third molars, *maxillary third molars rarely need sectioning*, as maxillary bone expands easily, being thin and elastic. Instances where the bone is thicker, sclerotic and less elastic as in old patients, tooth removal is enabled by bone removal rather than tooth sectioning. Chisel is contraindicated to section the tooth due to the danger of displacement of the tooth into the maxillary antrum.

Maxillary third molar teeth must not be sectioned unless absolutely necessary, as displacement of small fragments into the sinus or infratemporal fossa may occur.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.34** Schematic diagram showing the relationship of impacted maxillary third molar to the foor of the maxillary sinus

#### **14.9.4.3 Delivery of the Tooth**

This is achieved using small straight elevators or angled elevators with force exerted in the distobuccal direction. If angled elevators are used, access may be easier. Angled elevators which can be used for this purpose are the Warwick James, Cryer, Pott's, and the Apex elevator. During surgical removal, placement of Laster retractor will help in better access and vision and may also prevent accidental displacement of the maxillary third molar into tissue space beyond the tuberosity.

During tooth elevation, one must remember the following points:-

1. Due to the proximity of the maxillary sinus and the infratemporal fossa, pressure should not be exerted in the superior direction during bone removal and delivery of the tooth.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.35** (**a**–**d**) Steps in the surgical removal of a mesioangularly impacted maxillary third molar. (**a**) Incision to raise a triangular fap, (**b**) Mucoperiosteal fap refected, (**c**) Overlying bone removed from

occlusal and buccal aspect up to the cervical line and elevation of tooth, (**d**) Suturing completed

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 14.36** (**a**) Bone removal achieved on the occlusal and the buccal aspect of tooth down to the cervical line to expose the entire crown, in a disto angular maxillary third molar impaction (**b**) Delivery of the tooth using an elevator


#### **14.9.5 Complications That Occur During Surgical Removal of Impacted Maxillary Third Molar**

1. *Tooth displacement into maxillary sinus*—This usually occurs in cases of partially erupted maxillary third molars, which have conical roots and are located close to the foor of the sinus. The risk increases if the root apex is in contact with the foor of the sinus, and the initial position of the tooth is high.

If this complication occurs, the tooth may have to be removed from the sinus in order to avoid infection. Initially, a suction tip may be placed at the sinus opening to retrieve the tooth. Alternately, saline irrigation into the sinus may be followed by applying the suction tip. If these methods do not work, it is best to stop attempts and place the patient on antibiotics and nasal decongestants. The tooth may be retrieved later through Caldwell-Luc approach, and the oro-antral fistula may then be closed. The tooth may also be removed using endoscopic sinus surgery [43, 44]. Detailed sequential approach of dealing with root/ tooth displaced into the sinus is mentioned in the Chap. 24 on Oro antral communication and fistula in this text book.

2. *Dislodgement into soft tissues*—The upper third molar can be inadvertently displaced into the buccal soft tissues [45] or into the infratemporal fossa [46]. Usually, this happens: (a) when the fap raised buccally is not adequate for access, (b) there is insuffcient visibility during the procedure, (c) improper extraction technique, (d) distolingual angulation of tooth, and (e) the crown of the third molar is at a level above the root apices of the adjacent molar tooth.

Dimitrakopoulos et al. [46] have discussed the various methods to remove a maxillary third molar that has been displaced into the infratemporal fossa.


#### **14.10 Complications of Impaction Surgery**

Complications of removal of impacted tooth can happen during the procedure and late after the procedure. Mild post operative pain, swelling and trismus can be expected inmost case and these three can be considered as a sequel ae of surgical removal of impacted wisdom teeth:-


#### **A. Complications that can occur during the Surgical Procedure:**

These can happen at various steps in the procedure, including:


#### 1. *Complications during incision*:

	- (a) *Use of bur.*
		- Accidental burns.
		- Laceration of soft tissues.
		- Injury to inferior alveolar neurovascular bundle.
		- Injury to adjacent tooth.
		- Injury to lingual nerve.
		- Necrosis of bone.
		- Emphysema.
	- (b) *Use of chisel*
		- Splintering of bone.
		- Fracture of mandible.
		- Displacement of tooth into lingual pouch.
		- Injury to lingual nerve.
		- Injury to the soft tissues or second molar.
	- Sectioning along an incorrect line.
	- Injury to mandibular canal.
	- Breakage of bur.
	- Fracture of impacted tooth/root.
	- Injury to second molar.
	- Fracture of mandible.
	- Displacement of the entire tooth or crown alone into the lingual pouch or lateral pharyngeal space.

#### **B. Postsurgical Sequelae and Complications**

	- (a) Lingual nerve injury
	- (b) Inferior alveolar nerve injury

The management of impacted third molars involves several considerations, and several controversies also exist in this area. Some of these are as follows:


At present, the various evidence-based guidelines available should help the clinician in taking informed decisions regarding third molar impactions [55–57]. Efforts have been made to reach a consensus in various areas, which itself shows conficting propositions, and only time will prove the best methods which can be used in the management of third molar impactions.

#### **References**


lar third molar impaction sockets. J Oral Maxillofac Surg. 2017 Jul;75(7):1322–9.


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## **Management of Impacted Canines**

George Varghese

Impacted canines are one of the common problems encountered by the oral surgeon. Patients may present at different ages and many cases will be incidental fndings. Close interaction with the paedodontist and orthodontist is required to get an optimal out come. Surgical removal may not be the best treatment in all the cases and particular treatement plan will have to be tailored for the needs of the patient. Localising the impacted canine seems not a challenge any more with the advent of CBCT, in indicated cases. This chapter elaborates on canine impaction, keeping in mind the basic principles mentioned in the chapter on third molar impactions. Premolars, incisors and other teeth may be impacted but most of the surgical principles and approaches mentioned for canine can be applied to them as well.

#### **15.1 Introduction**

Maxillary canine is the second most commonly impacted tooth, after the mandibular third molar. The permanent maxillary canine may be considered as impacted when the eruption of the tooth lags behind as compared to the eruption sequences of other teeth in the dentition. Diagnosis of maxillary canine impaction may be made by clinical examination and by radiography.

The normal path through which maxillary canines erupt may be altered due to changes in the eruption sequence in the maxilla, and also by space limitations due to crowding. It is essential to diagnose and treat this condition early, to prevent the development of complications. An ideal management protocol for impacted permanent maxillary canines should involve an interdisciplinary approach linking the specialties of oral and maxillofacial surgery, periodontology and orthodontics.

#### **15.2 Aetiology of Canine Impaction**

Although the exact cause of impacted maxillary canines remains unknown, multiple factors may play a role. Primary causes that have been linked to impacted maxillary canines include the rate at which roots resorb in the deciduous teeth, any trauma to the deciduous tooth bud, disruption of the normal eruption sequence, lack of space, rotation of tooth buds, premature root closure and canine eruption into a cleft. Secondary reasons include febrile diseases, endocrine disturbances and Vitamin D defciency. Impacted canine can be concomitant with other conditions.

Except the third molars, maxillary canines are among the last teeth to erupt. They usually develop high in the maxilla and need to travel a considerable distance before they erupt.

Local factors may also play a role in canine impaction, and these include:


**15**

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_15) contains supplementary material, which is available to authorized users.

G. Varghese (\*)

Principal, Professor and Head, Department of Oral and Maxillofacial Surgery, Pushpagiri College of Dental Sciences, Tiruvalla, Kerala, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 329

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_15


### **15.3 Classifcation of Impacted Maxillary Canines**

### **15.3.1 The Following Classifcation Suggested by Archer (1975)** [2] **is Very Practical**

*Class I: Impacted canines in the palate*.

	- 1. Horizontal
	- 2. Vertical
	- 3. Semivertical

### **15.3.2 Field and Ackerman (1935) Classifcation** [3]

#### *Maxillary Canines*

	- Crown in intimate relation with incisors.
	- Crown well above apices of incisors.
	- Crown near surface.
	- Crown deeply embedded in close relation to apices of incisors.
	- Crown between lateral incisor and frst premolar roots.
	- Crown above these teeth with crown labially placed and root palatally placed or vice versa.
	- In nasal or antral wall.
	- In infraorbital region.

#### *Mandibular Canines*

	- Vertical
	- Oblique
	- Horizontal
	- At inferior border.
	- On the opposite side.
	- Mental protuberance.

#### **Complications that Can Occur Due to Canine Impaction**


The clinical signs that indicate an impacted maxillary canine include:


### **15.4 Radiographic Localization of Impacted Canine**

The position of the impacted canine may be determined by visual inspection, palpating intraorally or by radiography.

Radiographic examinations may include periapical X-ray with cone shift technique, occlusal radiography, anteroposterior and lateral radiographic views of maxilla, OPG, CBCT, CT scan.

### **15.4.1 Radiographic Features to Consider**


#### 15 Management of Impacted Canines

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 15.1** Bilaterally impacted maxillary canine causing proclination and spacing of incisors. (**a**) Frontal view, (**b**) Occlusal view, (**c**) OPG showing impacted canines (yellow circle)


Going into the fne details of localization of canine is beyond the purview of this chapter. It is an area which has been extensively studied with regard to the various imaging modalities and their advantages.

Various radiographic methods are considered routinely by practitioners for localization. A few of them are mentioned below.

#### **15.4.1.1 Parallax**

This was frst introduced by Clark [5], and involves two radiographs taken at two different horizontal angles, but using the same vertical angulation. Owing to parallax error, the object that is further away appears to travel in the same direction as the direction in which the tube was shifted. The object nearer to the tube appears to move in the opposite direction [Same Lingual Opposite Buccal (SLOB) rule]. This technique can also be performed with differing vertical angulations (vertical parallax). There are different combinations of parallax techniques:


#### **15.4.1.2 OPG**

1. Magnifcation

The magnifcation technique depends on a principle known as 'image size distortion'. According to this, for a given 'focal spot'—flm distance, objects that are far away from the flm will appear more magnifed than those that are closer to the flm. This has been applied using OPGs for the impacted canine. (Wolf and Matilla [9]; Fox et al. [10]). In the OPG, if a canine looks bigger as compared to the adjacent teeth in the arch or the contralateral canine, it is probably located closer to the tube (palatal). If it is relatively small, it is located further away from the tube (labial). This method can be applied effectively only when the canine is not rotated, does not touch the incisor root and the incisor is not tipped [11].

Kuftinec [12, 13] asserts that if the canine's cusp is mesially at the root of the lateral incisor, the impaction is probably palatal but if the cuspid is found overlapping the distal half, a labial impaction is more probable.


#### **15.4.1.3 Computed Tomography**

Computed Tomography readily provides excellent tissue contrast and eliminates blurring and overlapping of adjacent teeth [16]. However, since CT exposes the patient to a high dose of radiation, the unfavourable relationship between cost and beneft to the patient determines its use only in particular cases, such as in the presence of craniofacial deformities. CT makes it possible to easily identify the position of impacted teeth and evaluate precisely the location of nearby anatomical structures and identify any root resorption in the adjacent teeth.

#### **15.4.1.4 Cone Beam CT**

Conventional CT imaging is associated with high radiation dose and high cost. Cone Beam Computed Tomography (CBCT) have been used instead for localization of the impacted canine. As CBCT uses cone-shaped radiation, the radiation dose is signifcantly reduced, and a high spatial resolution is achieved [17, 18].

#### **Reason for Surgical Removal of Impacted Canines**


#### **Treatment Options for Impacted Canines**


#### **15.5 Modalities of Management of Impacted Canine**

The impacted maxillary canine may be managed by several different techniques. The chosen method would depend on the degree of impaction, age of the patient, stage of root formation, presence of any associated pathology, dental condition of the adjacent teeth, position of the tooth, patient's willingness to undergo orthodontic treatment, available facilities for specialized treatment and patient's general physical condition.

1. *Extraction of primary canine.*

This method is as an interceptive form of management. Extraction of the deciduous tooth may be considered when the maxillary permanent canine is not palpable in its normal position and the radiographic examination confrms the presence of an impacted canine. However, this treatment will not necessarily correct the problem. Surgical intervention may be required if the permanent canine fails to erupt within one year of the deciduous extraction.

2. *No treatment—Leave the tooth in situ.*

In some asymptomatic cases, no treatment may be required apart from regular clinical and radiographic follow-up. There is a small risk of follicular cystic degeneration, although the incidence of this is unknown. Rarely, odontogenic tumours may develop in relation to the impacted tooth.

3. *Surgical exposure of the tooth*.

This technique may be used in cases where there is enough space for the canine to erupt, and where the root formation is incomplete. Surgically exposing the crown of the canine may allow it to come into position by normal eruptive forces.

	- (a) The impacted canine must be favourably positioned.
	- (b) The patient must be compliant with both surgery and long term orthodontics.
	- (c) The patient must not have associated medical problems.

This technique is preferred for teeth that are in an unfavourable position, and which are likely to cause problems in the future. It may also be considered when a patient is not willing for orthodontic treatment or cannot afford it, even if the impacted tooth is in a favourable position.

6. *Surgical repositioning/Autotransplantation.*

Impacted canines that are malpositioned, but have a favourable root pattern (without hooks or sharp curves) may be considered for autotransplantation into the dental arch. This may be done by utilizing the socket of deciduous canine or frst premolar, depending on the amount of space needed and available.

#### **15.5.1 Surgical Exposure of Impacted Canines**

#### **Surgical Exposure Techniques**


Various studies have compared the effects of the different exposure techniques in the periodontium; however, a consensus is yet to be reached [22–24].

Chapokas et al. in 2012 have brought out a useful classifcation of maxillary canine impactions based on which the exposure technique may be decided [25].

#### **15.5.1.1 Procedure**

1. Palatally positioned canine

The location of the crown of the impacted canine may be determined by radiographs. The possible position of the crown is determined, and a cruciform incision made over this. Along the incision arms, faps are elevated on four sides so that the crown is uncovered. The faps may be excised. If there is haemorrhage, it can usually be controlled by pressure application. If there is any bone overlying the crown, it is removed and sharp edges are smoothened so that the crown lies in a saucer-shaped bony cavity. To prevent soft tissue regrowth over the exposed crown, a pack (such as a perio pack or roller gauze impregnated with iodoform or antibiotics) may be inserted or sutured in place. Another alternative technique is to use a crevicular incision, expose palatally and place orthodontic brackets as shown in Fig. 15.2.

2. Labially positioned canines

Any one of the following techniques may be employed depending on the depth and position of the impacted tooth:

(a) *Creating a surgical window/Gingivectomy:* This is done if the tooth lies just underneath the gingiva. The overlying soft tissue is simply excised to expose the crown.

If the impacted canine is close to the alveolar crest, or if a broad band of keratinized tissue covers the tooth, a surgical window may be created. Gingivectomy may be done when it is possible to uncover at least one

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 15.2** Exposure of a palatally impacted canine

half to 2/3 of the crown, leaving at least 3 mm of gingival collar. Usually in these cases, the tip of the impacted tooth lies near the cemento-enamel junction of the adjacent tooth (Fig. 15.3).

(b) *Closed eruption technique:* If the impacted canine lies in the middle of the alveolus, near the nasal spine, or high in the buccal vestibule or the palate, this technique may be indicated (Vermette et al., 1995) [19]. A fap is frst elevated over the area of the impacted tooth. If necessary, the crown is then exposed after removal of the overlying bone. An orthodontic bracket may be bonded to the crown and to the bracket, a traction wire is affxed. The fap is then sutured, with the traction wire left exposed to the oral cavity. Suffcient time is given for the fap to undergo initial healing. Later on, the traction wire may be connected to an archwire and optimal force may be applied as needed for the tooth to erupt. Drawback of this technique is that the tooth cannot be inspected directly once the fap has been sutured (Fig. 15.4).

(c) *Apically positioned fap:* In cases where the cervical portion of the crown does not lie within the attached gingiva, removal of the soft tissue may cause the attached gingiva to be lost. Later on, this can lead to periodontal problems. In such a case, it may be better to use an apically repositioned fap.

The fap is designed in such a way that vertical incisions are placed on the soft tissue at the distal side of the lateral incisor and at the mesial side of the frst premolar. Then a horizontal incision is made that links the two vertical incisions. Subsequently, after locating the crown of the impacted tooth, the fap may be sutured back into at the apical end, while the crown is exposed to the oral cavity (Fig. 15.5a, b).

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 15.4** Closed eruption technique for labially impacted canine

**Fig. 15.3** Exposure of labially impacted canine by surgical window technique

©Association of Oral and Maxillofacial Surgeons of India

#### **15.5.2 Surgical Removal of Palatally Impacted Maxillary Canines**

If the impacted maxillary canine is in an unfavourable position, and cannot be brought into normal occlusion, it should be removed earlier rather than later. This is because increasing age increases the diffculty of the procedure, and by removing early, damage to the adjacent structures may be minimized.

#### **15.5.2.1 Surgical Anatomy**

The impacted canine is separated by a thin layer of the bone from the maxillary sinus and nasal cavity (Fig. 15.6). Infrequently, this bone may be absent. In these cases, the risk of tooth or root displacement into the maxillary sinus is high. It is also not uncommon to have the likelihood of creating a communication between the oral cavity and antrum, which may lead to post-operative nasal bleeding.

#### **15.5.2.2 Procedure** (Fig. 15.7a–d) (Fig. 15.8a, b)

The incision is initiated in the gingival margin on the palatal side from the ipsilateral frst premolar and, depending on the position of the impacted tooth, is extended up to the contralateral lateral incisor or premolar.

In cases of unilateral impaction, instead of extending the incision to the contralateral side, a vertical incision may be given in the mid palatal region. In situations where there is bilateral canine impaction and both teeth are close to the midline, the incision should always extend between the frst or second premolars of both sides (Fig. 15.8). Elevation of a single palatal fap not only avoids sloughing but also provides adequate visualization. This method may pose a risk of haemorrhage from the nasopalatine vessels which can, however, be controlled by pressure pack or by electrocautery.

The mucoperiosteal fap is then refected to reveal the palatal bone and the tooth. Division of the nasopalatine vessels and nerve may be done for further exposure.

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 15.8** (**a**, **b**) Palatal fap elevation for exposure of bilaterally impacted palatally positioned canine. (**a**) Flap outlined from the second premolar on one side to the second premolar of the opposite side, (**b**) Following refection of the mucoperiosteal fap, multiple drill holes are placed in the bone overlying the crown. These drill holes are then connected together to remove the bone thereby exposing the crown

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 15.9** (**a**, **b**) Incisions for removal of labially placed canine. (**a**) Semilunar incision, (**b**) Trapezoidal (3 sided) incision

The crown of the tooth may be visible occasionally, or a bulge may be felt. Bone around the area is removed with bur, taking care to protect the roots of the adjacent teeth from damage. Once adequate bone is removed, a groove is prepared on the mesial side and an elevator may be inserted into it. An attempt is made to luxate the tooth. Once the crown is moved out, it may be grasped using an upper anterior or premolar forceps. Dislodgement of the root apex may require a certain amount of torsion, as this is often curved.

If the tooth is resistant to elevation, more bone removal is done to enlarge the opening. Tooth sectioning (odontotomy) may be carried out using a straight fssure bur if there is any obstruction to movement (Fig. 15.7c, d). The crown portion is removed frst. A portion of the root may then be visualized. If not, bone is removed to expose the root. A hole is created in the root and an elevator is used to engage this and remove the root.

Meticulous debridement and curettage is done to remove the tooth follicle. Saline irrigation is used to clear out bone debris. The fap is replaced and sutured into position. It is held in close contact with the palatal bone by pressing a gauze pack with the dorsum of the tongue, for an hour or two. Healing follows without any complications.

To decrease chances of hematoma formation, a prefabricated clear acrylic plate may be used to cover the palate post-operatively.

#### **15.5.3 Surgical Removal of Labially Positioned Impacted Maxillary Canine** (Fig. 15.9a, b) (Video 15.1)

#### **15.5.3.1 Incision**

A semilunar incision (Fig. 15.9a) is usually used, and it provides good exposure. The lower part of the incision must lie at least 0.5 cm away from the gingival margin.

For cases that are deeply impacted, triangular faps (2 sided) or trapezoidal faps (3 sided) may be used, with incisions along the gingival margin and relieving incisions. (Fig. 15.9b).

#### **15.5.3.2 Operative Procedure** (Fig. 15.10a–f)

#### (Fig. 15.11a–i)

The mucoperiosteal fap is elevated and the bone with the tooth bulge is exposed. Using a bur, a window is created over the crown prominence. The window is enlarged so that the entire crown is exposed, taking care not to cause damage to the adjacent tooth roots. The tooth is then luxated using an elevator.

If there is any resistance during elevation, the tooth must be sectioned, so that the fragments can be removed easily. If three fragments are created, the middle one may be removed frst, and the remaining two fragments may be elevate using the resultant space (Fig. 15.10a–f).

The area is carefully debrided and checked for a residual follicle, which must be removed. The mucoperiosteal fap is repositioned and sutured (Fig. 15.11a–i) shows the localisation and surgical removal of a labially positioned impacted maxillary canine.

**Fig. 15.10** (**a**–**f**): Schematic diagram showing surgical removal of labially impacted maxillary canine. (**a**) Impacted maxillary canine. Note the relationship of the cuspid to the roots of the adjacent teeth, nasal cavity and maxillary sinus. (**b**) trapezoidal mucoperiosteal fap refected. (**c**) Drill holes placed in the cortical plate overlying the crown so as to expose the crown, after the full exposure of the crown, elevator is applied beneath the crown to mobilize the tooth, (**d**) If the tooth is resistant to elevation, the crown is sectioned using bur and it is removed, (**e**) Cavity created following removal of crown, (**f**) The root is moved into the space created by the removal of the crown and it is then removed

#### **15.5.4 Removal of Maxillary Canine in an Intermediate Position** (Fig. 15.12a–h)

The impacted maxillary canine may be located in an intermediate position, with the root oriented labially and the crown palatally, or vice versa. Removing a maxillary canine in the intermediate position may be challenging and may take more time as it may require a labial and palatal approach. The risk of damaging adjacent teeth is also higher with teeth in an intermediate position. CBCT or CT scan is very useful to locate the exact position of such a tooth. Figure 15.12a–h illustrates the steps involved in removing an impacted canine that has its root oriented labially and crown palatally.

#### **Complications of removal of maxillary canines:**


**Fig. 15.11** (**a**–**l**) show the clinical and radiographic images of the steps in removing a labially impacted canine by odontectomy. Bilaterally impacted maxillary canines (**a**) Intra-oral right lateral view, (**b**) OPG showing 13 in inverted position (yellow circle) with close proximity to maxillary sinus and impacted 23 (in red circle). CT of the same patient showing the relationship of the inverted 13 (yellow circle) to adjacent

structures such as maxillary antrum, nasal foor and nearby teeth. (**c**) Sagittal view, (**d**) Coronal view, (**e**) Axial view, (**f**) 3-D view. Steps in the surgical removal of impacted 13. (**g**) Incision marked, (**h**) Mucoperiosteal fap refected, (**i**) Tooth division done, (**j**) Tooth removed and debridement (**k**) Suturing completed, (**l**) Specimen

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 15.11** (continued)

#### **15.5.5 Management of Impacted Mandibular Canines**

Impacted mandibular canines are not as frequent as maxillary canines, and are usually found in a labial position. However, they may occasionally migrate to the mental protuberance or even the lower border of mandible, where they can lie in a transverse position. They can also drift to the opposite side of the mandible, referred to as transposition/transmigration of the canine. It must be noted that these teeth retain their original innervation, which is important to consider while administering local anaesthesia.

The diagnosis of an impacted mandibular canine is similar to that of the impacted maxillary canine, and it presents with similar features. These include retained primary teeth, proclination/displacement of adjacent incisors or clinical features associated with cyst formation. Impacted canines may not be associated with any symptoms, and may be accidentally discovered during the routine radiographic exami**Fig. 15.12** (**a**–**h**) Schematic diagram showing the steps in the surgical removal of impacted maxillary canine with root on the labial side and crown on the palatal side. (**a**) Outline of the impacted canine and its relation to the roots of the adjacent tooth. Note the semilunar incision marked, (**b**) Outline of the crown of the impacted canine on the palatal aspect, (**c**)

Mucoperiosteum refected on the buccal side overlying the bone to be removed and the root of the impacted tooth sectioned. An elevator is being used to dislodge the root, (**d**) Empty socket after removal of the root. (**e**) Palatal fap is outlined and refected. Bone covering the crown of the impacted tooth is removed using bur. (**f**) Using a blunt instrument placed in the socket of the tooth on the buccal side, pressure is exerted on the cut end of the crown (see black arrow) to push the crown palatally, (**g**) Empty socket on the palatal side after removal of the crown, (**h**) Flap is replaced back and suturing completed

©Association of Oral and Maxillofacial Surgeons of India

nation, or during the investigation of other dental conditions. Sometimes, however, these teeth can cause recurrent pain and infection.

Dalessandri et al. in 2017 opined that the most common treatment strategies for the treatment of mandibular canine impactions are surgical extraction and orthodontic traction. Surgical extraction and radiographic monitoring were suggested for transmigrant mandibular canines: The authors proposed a decision tree in order to guide practitioners through the treatment plan of impacted mandibular canines [26].

#### **15.5.5.1 Treatment Options**

The impacted mandibular canine may be treated using one of the following strategies:

	- (a) Pathology such as follicular cyst or tumour in relation to the impacted tooth.
	- (b) Orthodontic reasons, such as the need to move an adjacent tooth into the area of impaction.

#### **15.5.5.2 Surgical Anatomy** (Fig. 15.13)

The bone in the mandibular canine region consists of a thick lingual cortex and a thin buccal cortex. The impacted tooth usually lies mesial or distal to the actual canine region. A buccal fap must ideally be used for surgical access, as a lingual fap may not provide adequate access, and is associated with increased post-operative morbidity. While raising the buccal fap, the mentalis muscle insertion (at the mental fossa) and incisive muscle insertion (at the height of the canine alveolus) are divided.

#### **15.5.5.3 Removal of Mandibular Canine**

#### (Figs. 15.14 and 15.15)

For tooth exposure, a trapezoidal (3 sided) flap is used. Alternately, a horizontal incision may be made below the attached gingiva. If the tooth lies close to the lower border of the mandible, an additional incision may be needed extra-orally for proper exposure. As in the case of maxillary canine in the labial position, bone removal is done with bur. The tooth may be elevated in toto, or may require sectioning if resistance is met (Figs. 15.14a–h and 15.15).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 15.13** Surgical anatomy of mandibular canine area

#### **15.5.5.4 Complications of Surgical Removal**

These Include the Following


#### **15.6 Summary**

The management of impacted canine teeth requires skilful handling and careful observation on the part of an oral and maxillofacial surgeon. If any tooth is absent in the dental arch after the normal time of eruption has lapsed, the surgeon must investigate. The management of an impacted tooth is simple if the basic principles of surgery are followed appropriately for all the teeth. The case must be evaluated carefully for proper diagnosis and treatment planning. Treatment planning requires a multidisciplinary approach, and the general dental surgeon must consult with the oral and maxillofacial surgeon, orthodontist and paedodontist for achieving optimal results.

**Fig. 15.14** (**a**-**h**) Schematic diagram showing steps in the surgical removal of impacted mandibular canine. (**a**) Incision to raise a trapezoidal fap, (**b**) Mucoperiosteal fap refected and the bone overlying the crown removed using bur and chisel, (**c**) Crown of impacted canine exposed, (**d**) Elevator is applied in an attempt to luxate the tooth. (**e**) if

elevation unsuccessful tooth division is performed using bur, (**f**) Crown removed and more of the root exposed to create a purchase point on the root using bur, (**g**) Root removed using an elevator applied at the purchase point, (**h**) Closure of the incision

**©Association of Oral and Maxillofacial Surgeons of India**

**Fig. 15.14** (continued)

**Fig. 15.15** (**a**–**m**) Shows the clinical and radiographic images of the steps in removing a labially impacted canine by odontectomy. Impacted left mandibular canine (yellow circle) with an associated odontome (**a**) OPG showing impacted 33, (**b**) CT Axial view, (**c**) Coronal view, (**d**) Sagittal view. (**e**) Intra-oral view, (**f**) Mucoperiosteal fap refected, (**g**)

Overlying odontome exposed, (**h**) Odontome removed and crown of 33 exposed. (**i**) Sectioning of crown of 33, (**j**) Removal of crown and root of 33 followed by debridement, (**k**) Suturing completed (**l**) Specimen of 33 with follicle and odontome, (**m**) Pressure dressing applied to reduce oedema

346

**Fig. 15.15** (continued)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 15.15** (continued)

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Endodontic Surgery**

Deepti Simon

# **16**

#### **16.1 Defnition**

Endodontic surgery is a dental procedure to treat apical periodontitis in cases that did not heal after nonsurgical retreatment or, in certain instances, primary root canal therapy [1]. It is the branch of dentistry that deals with the diagnosis and treatment of lesions of endodontic origin, which cannot be treated by or do not respond to conventional root canal therapy.

#### **16.2 Historical Frame of Reference**

Guerini documented the frst endodontic surgery as incision and drainage of an acute endodontic abscess, approximately 1500 years ago [2]. Infected root sections were removed, and the healthy tooth portion was retained in attempting to cure infected teeth for about 200 years. Histological bone regeneration was demonstrated in treated cases of infected periapical lesions in 1930 [3]. For a long time, pulpless teeth were implicated in a plethora of systemic disorders like nephritis and arthritis by the exponents of the focal theory of infection [4].

The terms apicoectomy, periapical surgery, periapical endodontics, root end surgery, apical microsurgery, and surgical endodontics have been used in the literature. Apicoectomy, which means cutting the root apex, limits the understanding of the procedure, which includes removal of the irritants in the root canal system and the periapical pathology as well. Today, endodontic surgery is one of the most puissant branches of dentistry and falls in the twilight zone among surgery, dentistry, and endodontics. Recent

D. Simon (\*)

advances in techniques and materials have resulted in a paradigm shift toward a more judicious strategy for treating periapical pathologies. The new benchmark for success is tissue regeneration. Nonsurgical retreatment for endodontic failures and surgical endodontics has been radically revolutionized by the introduction of the "microscope".

A periapical lesion is defned as any radiolucent image exceeding 1 mm in the periapical vicinity of the tooth. Lesions with a mean diameter > 5 mm are classifed as large lesions, and those less than or equal to 5 mm are classifed as small lesions [5]. In lesions greater than 10 mm, tooth extraction may or may not be done after considering factors like tooth mobility, pain, and the periodontal condition [6]. A periapical lesion may be noticed clinically or radiographically at a dimension of 5 mm [7].

#### **16.3 Indications for Endodontic Surgery** [8]


#### **16.3.1 Updated Indications (The European Society of Endodontology) (2006)** [9]

1. Radiological fndings of apical periodontitis and/or symptoms associated with an obstructed canal (the obstruction proved not to be removable, displacement of the obstruction did not seem to be feasible, or the risk of damage was too great)

Department of OMFS, Government Dental College, Trivandrum, Kerala, India

Kerala University of Health Sciences, Thrissur, Kerala, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 349

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_16


### **16.4 Relative Contraindications**


#### **Principles of Endodontic Surgery**


#### **Classifcation of Endodontic Surgery [8]**

	- (a) Incision and drainage
	- (b) Cortical trephination
	- (c) Decompression procedures
	- (a) Curettage
	- (b) Root end resection
	- (c) Root end preparation
	- (d) Root end flling
	- (a) Perforation repair
		- (i) Mechanical (iatrogenic)
		- (ii) Resorptive
	- (b) Periodontal management
		- (i) Root resection
		- (ii) Tooth resection
		- (iii) Intentional replantation

### **16.5 Preoperative Assessment and Planning**

#### **16.5.1 Anatomical Refections**

The nasal foor, maxillary sinus, inferior alveolar, and mental and greater palatine neurovascular bundles offer potential road blocks to the surgeon.

### **16.5.2 Important Considerations in the Maxilla and Maxillary Sinus**

If the roots of the maxillary anteriors are very long and the lesion extends superiorly, proximity to the nasal foor should be borne in mind. Eberhardt et al. have commented that the mesiobuccal root apex of the maxillary second molar is closest to the sinus foor and the buccal root apex of the maxillary frst premolar is the farthest [10]. The greater palatine neurovascular bundle presents a risk while working on the palatal roots of maxillary molars. If the vessel is severed, pressure must be applied by packs or bone wax and the eventuality of external carotid artery ligation should not be precluded. Vertical releasing incisions on the palate are to be eschewed, and if these are unavoidable, it is prudent to place the same between the maxillary canine and frst premolar, where the artery has a narrow caliber. Palatal roots can be accessed buccally or across the sinus or palatally (direct approach). The contour and depth of the palatal vault greatly determine the surgeon's accoutrement; greater the depth, greater the comfort.

Inadvertent loss of root tips into the maxillary sinus should be avoided and retrieved endoscopically if such a situation arises. Sinus communications, if they occur seldom, pose an impediment to healing neither are they implicated in sinustis [11]. The sinus membrane usually regenerates, and a thin bone forms at the apex [12]. Shallow vestibule, palatally or lingually inclined roots, compounds the surgeon's diffculties.

### **16.5.3 Important Considerations in the Mandible**

In the mandible, the facial artery, mental nerve, and inferior alveolar neurovascular bundle should be reckoned with. The facial artery can be safeguarded if incisions placed in the vicinity of the mandibular frst molar are not extended beyond the vestibular depth. The route taken by the inferior alveolar neurovascular bundle is of particular signifcance. It winds buccal (second molar) to lingual (frst molar) and then again buccal (the second premolar) before it exits the mental foramen [12]. In the vertical dimension, the mandibular sec-

**Table 16.1** Anthropometric measurements of signifcance in endodontic surgery [10, 12]


ond molar is closest to the canal as when compared to the mandibular frst molar or second premolar. For all practical purposes, the mandibular second molar is not conducive to endodontic surgery and should be attempted bearing in mind these encumbrances. The mandibular anteriors offer a particular challenge while performing perpendicular root resection [12].

Excessive salivation, shallow vestibule, thick alveolus, and small rima oris are other determinants. A comprehensive assessment of all these variables is mandatory prior to embarking upon endodontic surgery (Table 16.1).

#### **16.6 Investigations**

Until recently, periapical radiographs were the workhorse of endodontic surgery. Their obvious shortcomings were due to compression of three-dimensional structures into a twodimensional image and geometric distortion of anatomy. In the year 2000, Cone Beam Computer Tomography (CBCT) was introduced to dentistry. The limited CBCT offers higher resolution, and images are displayed in three planes: axial, coronal, and sagittal. Simultaneously, radiation dose is comparable to panoramic x-rays, and superimposition of neighboring structures is obviated [12]. The relationship between the teeth apices and anatomic structures, variations in root morphology, additional canals, and external root resorption are just a few of the diagnostic conundrums that can be assessed via CBCT.

Surgical workup also includes complete blood count, routine urine examination, viral markers, and a thorough medical history. Appropriate regulation of insulin, anticoagulants, and other drugs should be undertaken in liaison with the attending physician.

A well-informed patient is the best patient. The importance of informed consent cannot be overdrawn, and the patient is entitled to know about the prognosis, benefts, and surgical complications, anticipate damage to vital structures, and follow up. Communication regarding the above details is mandatory, and the patient should be made aware of alternate treatment modalities like extraction followed by implant placement.

#### **16.7 Anesthesia and Hemostasis**

#### **16.7.1 Premedication**

Nonsteroidal anti-inflammatory drugs (NSAIDs) in conflation with a long-acting local anesthetic can scale down postoperative pain. Ainsworth surmised that routine use of prophylactic antibiotics in periapical surgery is unwarranted [12]. A presurgical mouth rinse with chlorhexidine gluconate (0.12%) will reduce the salivary bacteria significantly, especially their growth on sutures and wound margins, but may obtrude with fibroblast reattachment to the root [12].

Most patients tolerate the surgical procedure under local anesthesia but for the apprehensive, conscious oral sedation with benzodiazepines or nitrous oxide/oxygen inhalation should be opted for. Diazepam 10 mg can be started on the night before the surgery, and another dose can be administered 1 hour before the procedure [13].

#### **16.7.2 Local Anesthesia and Sedation**

The merits and demerits of various local anesthetics have been elaborated in detail elsewhere in this book. Conventional nerve blocks are augmented by local infltration. Of equal momentousness is the preference for the vasoconstrictor. Adrenaline in concentrations ranging from 1:50,000, 1: 100,000, and 1:200,000 have performed commendably.

#### **16.8 Surgical Access**

#### **16.8.1 Armamentarium**

Incisions can be placed with no.11, no. 12, no 15, or no. 15-C blades (Fig. 16.1). Sharp, blunt dissection and elevation of the mucoperiosteal fap are accomplished by a Molts' or Howarths' periosteal elevator (Fig. 16.2). Endodontic tissue retractors like Austin, Seldon, or Minnesota should be judiciously selected in order to minimize trauma to the mucoperiosteal fap and neurovascular bundles (Fig. 16.3). Overlying bone is cut with No.4/6/8 round burs or 701/702 fssure burs (Fig. 16.4). These can be used to resect the root apex as well. Surgical handpiece with 45 ° angle head and rear air exhaust is advocated. Sharp surgical curettes like Lucas curette, angled periodontal curettes, and spoon excavators help to remove the infamed soft tissue from the bony cavity (Fig. 16.5).

Root end resections can be done either with conventional burs or lasers (Er-YAG or Ho-YAG lasers) [14, 15].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 16.1** No. 15 and No. 15 C Blades

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 16.2** Molt's Periosteal Elevator and Howarth's Elevator

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 16.3** Austin retractor and Minnesota retractor

The advantages of lasers include greater patient comfort, decreased vibrations, lesser surgical site contamination, and minimal trauma to the juxtaposed tissues.

Ultrasonic microsurgical tips are invaluable for root end preparation. Earlier, hand fles and rotary burs were used. Tefon sleeves, pluggers, and Messing gun-type syringes can be used to place various root-end flling materials like MTA (Fig. 16.6). Review of literature validates the superiority of microsurgical techniques over conventional surgery (97% to 59%) [1]. The dental operating microscope, ultrasonic tips, and diamond coated micromirrors (Fig. 16.7) have found their niche in the surgeon's armamentarium. Micromirrors (Fig. 16.8) can be used to inspect the buccal and lingual walls of the retrocavity. Microsurgical scalpels are useful for incising the intrasulcular areas and dissection of the interproximal papillae.

#### **16.8.2 Surgical Management**

The aims of periapical surgery are to visualize and debride the affected area and provide hermetic seal at the root end that aids in periodontal regeneration (Figs. 16.9, 16.10 and 16.11). Gutmann and Harrison [4] have categorized faps as


©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 16.6** Pluggers and Messing gun syringe

**Fig. 16.4** No.701 bur and No.4 bur

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 16.5** Lucas curette, Spoon excavator, and Periodontal curette

The main difference is that marginal interdental tissues are included in the full flaps, whereas the latter conserves them. Researchers opine that limited flaps prevent loss of papilla height, but careful adaptation of the reflected soft tissues rarely causes changes in gingival attachment level. It is vital to preserve the root attached tissues. In the absence of periodontal pathology, anatomic and functional status quo can be maintained via full mucoperiosteal flaps. Elevating palatal flaps is by

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 16.7** Microsurgical root end surgery

and large a cumbersome affair. If the clinical situation demands a palatal approach, the envelope and triangular flaps can be considered. Contrary to popular teaching, vertical incisions can be placed on the palate, rather than stretching and renting a flap, which may impede healing. This approach is best reserved for palatal roots for posteriors. Anterior palatal cysts can be accessed labially or palatally, according to the surgeon's discretion. To aid in surgical access, it is prudent to pass a long suture through

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 16.8** Diamond-coated mirror

©Association of Oral and Maxillofacial Surgeons of India

#### **Fig. 16.9** Trapezoidal fap

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 16.10** Clinical image of a trapezoidal fap for periapical lesion in lower anterior region

the palatal flap and have the assistant retract the tissue. Table 16.2 details the advantages and disadvantages of various types of flaps that can be used for endodontic surgery.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 16.11** Submarginal incision

### **16.8.3 Basic Principles of Flap Design**


The position of the tooth in the arch, the dimensions of the periapical pathology, gingival recession, and the presence of artifcial crowns also determine the choice of the incision that is placed.

#### **16.8.4 Flap Elevation**

The horizontal element of a full mucoperiosteal fap commences in the gingival sulcus and severs the gingival attachment fbers to the crestal bone. The interdental papilla should be incised at the midcol level. While incising a limited fap, the horizontal component must conform to the contour of the marginal gingiva and should be 2 mm apical to the depth of



the gingival sulcus. The vertical incision should begin in the alveolar mucosa and proceed toward the crown till it abuts the horizontal incision. To achieve the above objectives fresh, sharp blades should be opted for.

Hemostasis and healing are enhanced if the entire mucoperiosteal fap is elevated as a single unit, due to adherence of the fap with its microvasculature. The broad end of the elevator can be maneuvered beneath the vertical incision, a few millimeters from the junction of the horizontal and vertical incision in the attached gingiva. This preserves the supracrestal root-attached fbers. This is followed by coronal dissection, and forces are directed toward the periosteum and bone. This technique is termed undermining elevation and should be continued throughout the length of the horizontal incision and apically to the alveolar mucosa [4]. An approximate distance of 1 cm from the apex should be exposed for adequate access. The bleeding tags seen on the bone contain periosteum that aids in healing and reattachment of the fap.

#### **16.8.5 Flap Retraction**

The soft tissues must be gently retracted to preclude the possibility of inadvertent crushing. This may lead to fap hypoxia, swelling, ecchymosis, and/or delayed healing. The retractor of a correct size should be selected and placed on cortical bone in such a way that the tissue is prevented from engaging with rotary instruments.

The periosteal surface of the fap should be irrigated with sterile, cool, and physiologic saline to keep it hydrated. The superfcial surface is more resistant to dehydration due to the stratifed squamous epithelium [16, 17].

#### **16.8.6 Hard Tissue Management**

Once the fap is raised, the surgeon encounters either intact cortical bone over the lesion or the lesion sans cortical bone. In the former scenario, it is imperative to localize the lesion and remove bone in the adjacent periapical area. Well-angled radiographs can aid in this aspect. Sounding the bone with the sharp end of the periosteal elevator can also be useful, as there is a change in resonance when one approaches the diseased area. It is also prudent to identify the root by calculating twice the crown length and then shave the thin bone at the apex. If digital technology is used, the distance from the alveolar crest to the root apex can be measured using the ruler function [3]. The root is smooth, hard, and yellow in color, surrounded by a periodontal ligament, and does not bleed on probing. Methylene

Bone is vulnerable to thermal damage at any temperature above the normal body temperature. This is the crucial aspect of periapical surgery and infuences the choice of burs, coolants, and handpieces. Bone when subject to temperatures between 40 °C and 50 ° C undergoes a spectrum of irreversible changes. These include reduction in microcirculation, tissue necrosis, fatty cell infltration, and decrease in alkaline phosphatase.

While selecting bone cutting burs, sharp ones with wide spaces between the futes are preferred. Round burs meeting these criteria promote excellent healing. Chilled saline effectively reduces the heat produced and fushes out the debris, thus enhancing effciency. Excess pressure applied to the bone is detrimental to the tissues and handpiece. Gentle shaving or brushing motion must be used in short, multiple phases.

Hirsch et al. have used a piezoelectric device to create a bony aperture while performing apicoectomies in maxillary anteriors. The buccal bone was removed, preserved in Hank's Balanced Salt Solution (HBSS), and later replaced in the bony crypt after the procedure, thus acting as an autologous bone graft. This is feasible in cases where there is minimal bone loss or in the presence of intact bone over the lesion [18].

The bony aperture should be wide enough to permit visual and surgical access into the lesion, enabling the insertion of bone curettes and excavators. In traditional root surgery, the size of the aperture is approximately 8–10 mm and 3-4 mm in microsurgery. The rate of healing is faster when the size of osteotomy is smaller. Granulomas and granulation tissues exhibit a propensity to bleed profusely, hindering the surgery. To circumvent this, local anesthetic with a vasoconstrictor can be injected within. Using a curette of appropriate dimension, the surgeon works from the periphery toward the center. The instrument is inserted between the tissue and the lateral edge of the cavity with its concave face toward the bone. This is continued all around the circumference of the cavity and slowly progresses toward the depth of the crypt in a scraping manner. After freeing all the tissue, it is gently grasped with a pair of tissue forceps and immersed in 10% buffered formalin solution. The specimen should not be left to dry. Lin et al. opine that complete curettage is not mandatory, if the irritant is eliminated [19]. Though a majority of periapical lesions have been diagnosed histopathologically as granulomas or cysts, there have been documented reports of perfectly innocuous looking periapical lesions diagnosed as odontogenic keratocysts, central giant cell granulomas, or squamous cell carcinoma [20, 21].

#### **16.8.7 Root end Preparation**

#### **16.8.7.1 Root end Resection** (Fig. 16.12**)**

Regeneration of alveolar bone, periodontal ligament, and cementum in the periapical area can be encouraged by removing the diseased root end tissues and placing a root end seal to stop the recontamination of the periapical region. Resection of apical 3 mm of the root apex will eliminate 78% of apical ramifcations and 93% of lateral canals, which could contain material that would contribute to the periradicular disease [12]. The isthmus area should be included in the resection in roots with multiple canals. Anatomical obstructions, broken instruments, and perforations can be removed, orthograde sealing can be assessed, and trapped lingual tissue can be curetted out. In the case of apical fenestration, the apex can be reduced below the surrounding cortex to enable bone formation over the apex. The resection should enable the surgeon to prepare a root end cavity and place a restoration within.

A smooth, fat resected surface is considered ideal. This should be assessed for cracks, anatomical variations, and orthograde obturating material by means of an operating microscope at high power magnifcation and methylene blue staining [2]. The resection is made in order to surround the flling by normal dentin. Conventionally, a 30–45° bevel was placed, but the advent of the microscope has enabled a resection perpendicular to the long axis of the tooth. This substantially decreases the number of exposed dentinal tubules. Cohen opines that this aids in root end cavity preparation beyond the

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 16.12** 2 to 3 mm root tip resection

coronal extent of the root surface and apical stresses are well distributed, thus reducing apical fractures [11].

After the perpendicular root resection, the root must be conditioned to remove the smear layer produced. This exposes the collagen matrix of dentin and promotes growth. 5% aqueous citric acid has been used for this purpose. EDTA and tetracycline have also been studied, but have not found clinical popularity.

#### **16.8.7.2 Root end Cavity Preparation**

A 3 mm-deep Class I cavity is prepared along the long axis of the tooth, in order to place the flling material [22]. Ultrasonic tips have been specifcally designed for this purpose. The tips produce less smear layer, need less beveling, and can be inserted through a smaller aperture. However, the ultrasonic vibrations can predispose to root fractures. This can be minimized when it is used at the lowest setting and with water coolant. Ultrasonic tips coated with stainless steel, diamond, or zirconium nitride are superior to uncoated tips. If the tips have a curvature of 70° or more, they are prone to fracture [23]. The root end flling is placed into the prepared cavity. When bonded materials like Retroplast are used, no root end preparation is needed; the flling is placed like a dome onto the resected root. This is termed bonded cap approach.

It is imperative to have a dry bloodless feld prior to placement of the root end flling regardless of the setting properties of individual flling materials. To achieve this, adrenaline-saturated pellets, bone wax, Gelfoam, surgical, calcium sulfate, thrombin, collagen, or ferric sulfate may be used. Electrocautery may also be used, but this may delay bone healing.

©Association of Oral and Maxillofacial Surgeons of India

Amalgam used to be the quintessential retrograde flling material as it is cheap, easy to use, and radio opaque. However, it may stain the tissues and is sensitive to moisture [3]. Research has yielded a plethora of retroflling materials, which has enhanced the outcome of endodontic surgery (Table 16.3).



After placing the root end flling, a radiograph must be obtained to assess its quality. If the radiograph reveals an incomplete root resection or an inadequate retrofll, the surgeon must rectify the above-said defciencies. These are the most common surgical pitfalls that contribute to endodontic surgical failures.

The surgical site is gently cleaned and irrigated with sterile saline to remove debris of hemostatic agents and flling materials. Bone grafts or guided regeneration barriers can be placed into the crypt if indicated, but sterile technique should be adhered to, at all times to obviate infection. Calcium phosphate bioceramics, bioactive glass composite, and bioactive self-setting cements have been evaluated in vitro as well as in vivo [24, 25]. The fap is repositioned and delicately compressed with a moist gauze to vent out the excess blood, and tissue fuids 4–0 Silk or 6–0 monoflament suture materials are used. Tissue adhesives like cyanoacrylate and fbrin may be used as alternatives in the future. Suturing commences at the corners, approximately 2–3 mm from the wound margins. Interrupted sutures and sling sutures work well for closure of full mucoperiosteal faps. Continuous locked suturing can also be done in marginal faps as it reduces the time taken for suturing.

Following wound closure, moist gauze is placed on the fap for 5 min to stabilize clot formation and hemostasis. Compressing the fap with sterile ice packs in the immediate postoperative period minimizes the thickness of the fbrin clot and enhances wound healing. Intermittent cold compresses for 20 min on the day of surgery aids in patient comfort. Analgesics are prescribed, and verbal and written instructions are given to the patient and primary care provider. The wound must be cleaned gently with cotton. Chlorhexidine mouthwash is benefcial and can be continued till sutures are removed, i.e., on the ffth day postoperatively. Sutures can be removed after 3 days in microsurgical procedures.

#### **16.9 Biology of Wound Healing** [12]

The dynamics of healing in endodontic surgery involve various mechanisms germane to the nature of the individual tissues. The soft tissue incision heals by primary intention, whereas the bone defect and resected root surface heal via secondary intention. The endpoint of surgery should be regeneration, rather than repair where the normal tissue architecture and function are restored instead of a fbrous scar tissue.

The soft tissue healing progresses through three phases, i.e., infammatory, proliferative, and maturation. The infammatory phase begins with clot formation. The local microvasculature contracts, the platelets release serotonin, and a protein-rich exudate enters the wound site. Intravascular aggregation of platelets forms a platelet plug, and the extrinsic and intrinsic pathways are activated. This results in a randomly arranged thick fbrin clot. Within 6 hours of clot formation, polymorphonuclear leukocytes enter the wound and decontaminate the area by phagocytosis of bacteria. Their activity tapers off by 96 hours; monocytes and macrophages continue the phagocytic activity. A reduction in macrophages hampers the next phase of wound healing, especially in the older population where there is a step down of estrogen regulation of macrophages. The proliferative phase is dominated by fbroplasia and angiogenesis. The granulomatous nature of the wound transforms into granulation tissue by the activity of cytokines like platelet derived growth factor (PDGF), fbroblast growth factor (FGF), and insulin-like growth factor (IGF-1). By the third day, fbroblasts lay down Type III collagen, which matures to Type I. Myofbroblasts orient themselves parallel to the wound surface and contract, thus drawing the wound edges together. Concurrently, capillary networks form within the wound stimulated by proangiogenic factors like vascular endothelial growth factor (VEGF), FGF, transforming growth factor α, β (TGF-α, β), and interleukin-1 (IL-1). An epithelial seal is formed on the surface of the fbrin clot by the frst day. In the next 5–7 days, the wound matures by the formation of larger collagen bundles.

In the osseous crypt, there is a hematoma and proliferation of granulation tissue, callus formation, and woven bone deposition, which is converted to lamellar bone. These events are regulated by TGF-β, PDGF, FGF, IGF, and bone morphogenic protein (BMP). At the root end, cementum forms over the resected surface. Cells responsible for cementogenesis are believed to originate from the ectomesenchymal cells in the tooth germ. By 28 days, the root end is covered by cementum.

#### **16.10 Postoperative Complications**


#### **16.11 Outcome of Endodontic Surgery**

Clinical and radiographic assessments are made to determine the outcome of periapical surgery. The Periapical Index (PAI) has been used for radiographic assessment in both surgical and nonsurgical series [26]. Ingle opines that the terms 'healed', 'healing', 'disease,' and 'asymptomatic' can be used to describe the outcome.


#### **16.12 Aids to Endodontic Surgery**

Loupes, endoscopes, and the operating microscope have enhanced visualization of the operating feld and thereby the quality of surgery.

#### **16.12.1 Endoscopes**

It has a rod lens system, camera head, and control unit with a monitor and light source placed on a mobile rack. The depth of perception is comparable with the naked eye. Tactile perception is excellent; diseased tissue behind and between roots can be visualized. Irrigation fuids can be used without clouding the visual feld. Fabbro and Taschiere have reported success rates of 91.1 and 90.7% using the endoscope [27]. They offer rapid and easy adjustment of the viewing angle, direct viewing sans micromirrors, which is versatile and transportable.

#### **16.12.2 Dental Operating Microscope**

The resolution of the human eye is 0.2 mm. The power can be increased by moving closer to the surgical feld, but can pose strain to the eye. Hence, magnifying lenses and illumination are used to bypass this problem.

The operating microscope offers up to 30 times magnifcation, coaxial light supply, and shadow free illumination. 200 mm objective lenses and 180° inclinable binoculars are optimum confgurations. Light can be sourced from either xenon or quartz halogen bulbs. Digital camera, video camera, and co-observation tube are included in the setup. Endodontic microsurgery amalgamates magnifcation, illumination, and microinstrumentation, leading to predictable treatment outcomes. Deeper root end cavities can be prepared, which follow the contour of the root, hence minimizing lateral perforation [28]. The high cost of the equipment and need for specialized training deter many from adopting this tool on a routine basis, but the high success rates should be suffcient encouragement for clinicians and patients to adopt this new tool.

#### **16.13 Future Perspectives**

The role of mesenchymal stem cells in regeneration of periapical tissues has been explored with great enthusiasm. Dental pulp stem cells (DPSCs) and those from exfoliated deciduous teeth are multipotent in capacity and can be used along with scaffolds and signaling molecules [29]. These entities, when combined in the ideal proportion, aim to recreate the embryonic milieu, hence augmenting the biological concepts of wound healing. The future may usher in radical changes in our approach to endodontic surgery in terms of materials and techniques with respect to regenerative medicine.

**Acknowledgments** Dr. Khaleel Ahamed Thaha, Assistant Professor, Department of Conservative Dentistry and Endodontics, Government Dental College, Kozhikode, Kerala.

#### **References**


#### **Additional Reading (Algorithm for Periapical Surgery)**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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## **Preprosthetic Surgery**

#### Bobby John

*The human mandible has no one design for life. Rather it adapts and remodels through the seven stages of life, from the slim arbiter of things to come in the infant, through a powerful dentate machine and even weapon in the full fesh of maturity, to the pencil-thin, porcelain like problem that we struggle to repair in the adversity of old age.*

Poswillo

### **17.1 History**

The management of discontented denture patients by the act of preprosthetic surgical procedures to enhance the denturebearing areas of the intraoral cavity is a daunting task, which has been performed by the oral and maxillofacial surgeon from time immemorial. Preprosthetic surgery encompasses a distinguished and evolving category of soft and hard tissue procedures.

Pre-prosthetic surgery has emerged from being virtually unknown, passed through a period of opposition and into a state of venerability, and has ultimately made a powerful impact on oral surgery and prosthetic dentistry alike.

A meticulously nurtured and evolved repertoire of ingenious salvage procedures is now alarmingly threatened by a populist 'implants-frst' belief that usurps, rather than expands, the traditional prosthodontic treatment spectrum.

Willard [1] is honoured to be the frst American dentist to call attention to proper preparation of the mouth for full dentures. Beers [2] in 1876 advocated excision of the alveolus after extraction of teeth, especially if the alveolar process is unusually exhibiting protuberance. Surgery has always been an integral part of the preparation of alveolar ridges for dentures. The last few decades have witnessed an escalating interest in preprosthetic surgery, which has harboured the development of many new techniques.

#### **17.2 Pattern of Resorption**

Immediately after extraction, the socket will suffer a reduction in the dimensions both in buccolingual and apicocoronal aspects. This catabolic process can be counteracted by the placement of implants. The resorption of the walls occurs in two phases, which are overlapping in nature. The frst phase is characterised by the resorption of bundle bone and replacement with woven bone. The second phase involves the outer surfaces. The exact aetiology for this bone loss is unknown. Roux [3] opined the loss of alveolar bone occurring after tooth loss in the old age is an illustration of disuse atrophy. According to studies by Wolff [4], the mass and structure of the bone can get adapted to the mechanical demands. The resorption is a multifactorial, biomechanical process that results from a combination of anatomic, metabolic, and mechanical determinants. Since all of these factors vary from one patient to the next, these different cofactors may combine in infnite variety of ways, thus explaining the variations in resorption between patients. So ridge resorption is a chronic, progressive, irreversible, and cumulative phenomenon resulting from physiologic, environmental and pathologic components.

Mercier [5] illustrated the general resorptive changes that take place in an edentulous ridge. He summarised the stages as follows:


**17**

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_17) contains supplementary material, which is available to authorized users.

B. John (\*)

Department of Oral and Maxillofacial Surgery, Government Dental College, Kottayam, Kerala, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 361

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_17

Based on these stages, he grouped the residual ridges as

Group 1—minor ridge remodelling.

Group 2—sharp atrophic residual ridge.

Group 3—basal bone ridge.

Group 4—basal bone resorption.

The pattern of resorption in maxilla differs from that of the mandible. Also, the pattern varies with the site in maxilla and mandible. The extensive study by Cawood and Howell [6] depicts the following conclusions.

Basal bone does not change shape signifcantly. But if subjected to harmful local effects, it undergoes change.

Alveolar bone exhibits signifcant changes in shape in both horizontal and vertical axes.

In anterior mandible, the bone loss is vertical and horizontal, but in posterior mandible, the bone loss is mainly vertical.

In anterior maxilla, the bone loss is both vertical and horizontal. The same pattern is exhibited in the posterior maxilla. To summarise, the stage of bone loss varies anteriorly and posteriorly and between the jaws.

#### **Box 17.1 Efects of Edentulism**


#### **Box 17.2 Goals of Preprosthetic Surgery**


#### **17.2.1 Types of Ridges**

Ridges can be classifed by their shape. There are V–shaped, U–shaped and knife edged types. The U shaped is the ideal while the V shaped, though successfully distribute the stress but may be unable to retain the peripheral seal during the jaw movements. Knife edged ones are a constant source of soreness under the stress.

A more scientifc categorisation is made by Cawood and Howell [6].

Cawood and Howell [6] classifcation of edentulous jaws:


#### **17.3 Treatment Planning**

The preliminary step is the assessment of the patient, which commences from the history taking to the physical examination. The role of radiograph is relevant especially the panoramic view to reveal the deep-seated disorders. Storer [7] found 32% of edentulous patients had an asymptomatic pathologic condition, which warrants the need for radiographic examination. Crandell and Trueblood [8] also advised radiographic examination to rule out the presence of pathologies, root remnants, and even impacted tooth. Radiographic assessment is one of the parameters in detecting bone quality.

Lekholm and Zarb [9] categorise bone quality as follows



#### **17.4 Ridge Correction Procedures**

#### **17.4.1 Alveoloplasty**

The term refers to the restructuring or resurfacing of the alveolar process bone to provide a functional skeletal relationship. Simple plasty insists on the reshaping of the alveolar bone during the extraction procedure. The sharp edges of the alveolus will impede the healing process with symptoms of pain and discomfort. The shape of the ridges with suffcient width and height should be able to distribute the forces properly.

Preservation of alveolar bone is of utmost importance in the extraction procedure. Simple alveolar contouring includes compression and infracture of the socket, but overcompression and reduction should be avoided. If extractions are carried out before the prosthesis fabrication, attempts are made to preserve the alveolus. In multiple extractions, postextraction irregularity exists, which warrants the need for extended alveoloplasty. Here, mucoperiosteal fap may be raised by a crestal incision to get adequate access for the bone reshaping. Extreme care has to be taken during fap elevation since the soft tissues are tightly adhered to the bony irregularities. The use of bone rongeur or fle is needed to smooth the edges, but large irregularities may be rectifed by rotary instruments. Ensure saline irrigation to keep the temperature below 47 degrees to prevent necrosis. Once the hard tissue is removed, the excess soft tissue is trimmed to prevent the instability of the prosthesis. Closure with absorbable sutures in running or lock stitch fashion is achieved.

#### **17.4.2 Intercortical Alveoloplasty**

In situations where the alveolar process is prominent but regular, the need for alveoloplasty by the removal of interseptal bone and collapsing the buccal or labial cortical plates to meet the palatal or lingual plates is warranted. This method was propagated by Dean and Mackay [10]. This is an ideal procedure in case of immediate denture placement and usually carried out in the anterior region (Fig. 17.1a and b). This is done by the placement of vertical bone cuts in the canine region through subperiosteal tunnels. Apply the digital pressure to infracture the bone. If unsuccessful, the labial plate can be fractured with an osteotome inserted through a horizontal subperiosteal tunnel made through the vertical lateral incision. The bone distal to the canine is rounded off to maintain the contour. Mucosa is sutured appropriately to retain the new position of the cortices and if needed an acrylic splint may be used to stabilise it.

#### **17.4.3 Genial Tubercle Reduction**

Genioglossus muscle is one which is adhered to the lingual aspect of the anterior mandible and when the resorption continues, the genial tubercle becomes more prominent and along with the attached muscles creating a displacement of prosthesis. In this case, the pronounced tubercle may be trimmed and released. This procedure may be done alone or in combination with procedures suggestive of lowering the foor of the mouth.

#### **17.4.3.1 Procedure**

A crestal incision from the midline to the midbody of mandible is made to get adequate access, followed by dissection in subperiosteal fashion, thus exposing the tubercle and the attached muscle. Muscle may be excised from the bony attachment by using a monoplanar electrocautery with care to be taken to achieve haemostasis or else chance of airway embarrassment by the occurrence of expanding hematoma. The exposed genial tubercle is trimmed by round or fssure bur. Further smoothening is made by bone fle. The fap is returned to the original position and closed by nonresorbable

**Fig. 17.1** (**a**) Incision for intercortical alveoloplasty (**b**) closure of wound

sutures. Anderson [11] proposed reattaching the genioglosus and geniohyoid muscles at a lower level. Here, he advocated using a sagittal incision in the midline in the periosteum and exposing the genial shelf. The tubercle is reduced and the incision is closed with absorbable sutures.

#### **17.4.4 Mylohyoid Ridge Reduction**

In cases of extensive resorption, the ridge becomes prominent and creates hurdle for the smooth placement of denture; hence, the need for ridge reduction occurs. The denture fanges impinge on the sharp mylohyoid ridge and patient experiences pain and discomfort. The advent of implants may obviate the need for such a surgical procedure, yet in many cases where implant placement is not feasible, the dentures become a necessity and the mylohyoid ridge reduction needs to be accomplished.

#### **17.4.4.1 Procedure**

The procedure can be carried out under local anaesthesia or sedation. After successful nerve block, the incision is carried out along the crest of the ridge in the posterior mandible area followed by subperiosteal dissection and exposure of the mylohyoid ridge and the attached muscle (Fig. 17.2a and b). The muscle is detached and relieved. The residual ridge is smoothed with fle, fap returned, and closed with sutures (Fig. 17.2c). Care is ensured to obtain haemostasis.

#### **17.5 Maxillary Tuberosity Reduction**

Maxillary tuberosity may be enlarged in size and it engorges the intermaxillary space and interferes with denture placement. The reduction of the tuberosity may be needed to create space for the placement of dentures. Generally, the intermaxillary distance should be at least 1 cm when patients are placed into the correct or planned vertical dimension of occlusion. The excessiveness of the tuberosity and the need for its reduction can be assessed by some clinical manoeuvres. An instrument like a dental mirror can be used to assess the vertical clearance by passing it between the tuberosity and retomolar tissues. The mirror may be positioned in the lateral aspect and the patient is instructed to open and close mouth so as to determine the need for reduction of tuberosity in the horizontal plane. The pneumatisation status should be ascertained before the reduction procedure is undertaken since the maxillary sinus may descend into the tuberosity. So a radiographic examination is essential prior to surgical management. An elliptical incision is made followed by subperiosteal dissection. The engorged tuberosity is trimmed to the desired level and excessive tissue is removed from both buccal and palatal side. The amount of bone removal can be dictated by a surgical guide that was created from study models. Rotary instrumentation, rongeur and a bone fle may be used to remove the bone. The faps are trimmed to leave the excess redundant tissue and sutured in place (Fig. 17.3a–f). Guernsey [12] proposed a different technique for the reduction of the tuberosity. He advised placing a horizontal incision superiorly in the vestibule from the premolar area to the posterior aspect of the tuberosity and a mucoperiosteal fap is released inferiorly to get access to the tuberosity region. Any excessive soft tissue of fbrous nature is removed from within the fap and excessive bone is also removed by using suitable instruments. To correct the redundancy of tissues, soft tissue may be removed from the superior aspect of the incision and fap is sutured back to the periosteum and a stent is placed. This method claims to increase the vestibular depth to some extent (Fig. 17.4a–d). Antral communication should be checked and if present managed accordingly.

©Association of Oral and Maxillofacial Surgeons of India

#### **17.6 Torus Removal**

*Tori,* meaning 'to stand out' or 'lump in Latin, refer to innocuous bony outgrowths. The aetiology of the occurrence is unclear. Early description of the occurrence of tori is found in the Proceedings of the Royal Society of Medicine by Rickman Godlee [13], which was followed by the reports from various authors and later beautifully summarised by Garcia Garcia [14]. In dentate individuals, the removal of torus may not be needed unless it impedes with functions or it generates discomfort. But in edentulous, the presence of tori precludes the smooth placement of denture, so the removal becomes mandatory. Other indications include mucosal surface getting traumatised with frequent episodes of ulceration, presenting with deep undercuts and multiple nodules and psychological issues. Literature also suggests tori as donor sources of autogenous bone for intraoral grafting procedures. Morraes et al. [15] and Hassan et al. [16] describe the versatility of the grafts from torus for reconstructive methods.

Classifcation of tori was initially proposed by Kolas [17], who classifed them according to number of nodes and their placement as bilateral single, bilateral multiple, unilateral single, and unilateral multiple [18].

Haugen [19] formulated the categorisation of torus based on the size. It is illustrated as.

Type A—small tori into less than 2 mm in their largest diameter.

Type B—medium—2–4 mm in their largest diameter.

Type C—large- and more than 4 mm in their largest diameter.

Reichart [20] in his modifcation of Haugen's classifcation suggested few changes:

Grade I—Tori up to 3 mm in their largest dimension, Grade II—Tori up to 6 mm in their largest dimension and.

Grade III—Tori above 6 mm belong to this group.

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**Fig. 17.3** (**a**) Bulbous tuberosity, (**b**) incision placed and fap raised (**c** and **d**) reduction, (**e** and **f**) sutured incision

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 17.4** Clinical photograph showing (**a**) bulbous tuberosity (**b**) incision (**c**) fap refection (**d**) sutured wound

#### **17.6.1 Palatal Tori Removal**

As in any surgical procedures, here also the general systemic condition of the patient may be ascertained and the patient should be warned of the potential complications like the perforations leading to oronasal communication and wound dehiscence. To overcome this problem, preoperatively an impression may be made and cast is fabricated and splint is prepared. Palatal tori may be of different shapes, like lobulated or nodular. The morphology of the torus dictates the incisions required to expose it. Surgical access is accomplished by various types of incisions, "C-" or "U-" shaped incision, palatal incision or double "Y" incision also known as open-door technique. Most commonly used is double Y incision (Fig. 17.5a–f). After successful anaesthesia, a midline incision in anteroposterior direction is made from a few

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 17.5** (**a**) Incision, (**b**) fap raised, (**c**) multiple grooves made, (**d**) fnal trimming by acrylic trimmer, (**e**) excess soft tissue trimmed, (**f**) closure

mm ahead of the anterior margin of the torus and continued posteriorly to the most posterior visible point of the torus. Oblique-releasing incisions may be placed at the anterior end of the midline incision and may be extended laterally and anteriorly to end lateral to the lateral margins of the torus. From the posterior end of the midline incision without violating the soft palate, posterior releasing incisions may be placed to extend obliquely in a lateral and posterior direction. Thus, a fair access is obtained. The subperiosteal fap is raised. The small torus can be easily removed by round. But in case of large ones, grooves are created and separated into discrete segments with bur and then by osteotome (Fig. 17.6).

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**Fig. 17.6** Clinical photograph showing palatal tori and surgical exposure, double Y-incision used

Copious irrigation is done to clear the debris and fap repositioned in primary fashion. The fabricated stent may be placed to avoid the haematoma and the dead space formation.

#### **17.6.2 Lingual Torus**

The lingual tori are found in the lingual aspect of the alveolar ridge in the canine and premolar regions. They vary in size and shape; some are pedicled, while others are broad based. An intrasulcular incision without releasing is made from the lingual midline to a point beyond the posterior limit of the tori. In edentulous case, the incision may be placed in the crest of the alveolar ridge. A full-thickness fap is raised to expose the tori and if needed local anaesthetic may be injected in the area to balloon the tissues for easy elevation of the fap. The vertical-releasing incision should be avoided to prevent the vascularity compromise.

The lingual torus may be removed by bur or osteotome. Smaller ones can be easily removed by bur, but the larger require cleavage plane created by bur and later completed by osteotomes. After the removal of the tori, it is essential to check the surface and clear of the irregularities by the use of rongeur and bone fles. The fap repositioned and sutured.

#### **17.7 Exostosis**

It is a benign osseous hypertrophic formation with more predilections to the maxilla. A mucoperiosteal fap is elevated after adequate infltration of the mucosa. The bone is resected and smoothed with an osteotome or a bur. The smooth placement of the prosthesis is achieved by the facilitation of the errorless foundation, constituted by both hard and soft tissues. In many cases, the hard-tissue framework may be normal, but the soft-tissue impediments affect the stability of the prosthesis. So, the correction of the interferences by the abnormal soft tissues is needed.

Apart from hard tissues, sometimes soft-tissue interferences inhibit the smooth placement of the prosthesis. The unfavourable soft-tissue framework affects the stability of the prosthesis and needs correction by various procedures.

#### **17.8 Excision of Reactive Infammatory Papillary Hyperplasia**

This is commonly associated with prolonged wearing of an ill-ftting denture. The condition is recognised as reddened, nodular, or papillary excrescences arising from the palatal mucosa. It can be seen in areas where the denture fanges rest. Removal is accomplished by local anaesthesia or sedation (Fig. 17.7).

#### **17.9 Frenectomy**

Active and strong frenal attachments interfere with the placement of dentures and the relief of attachments are needed. Various incisions like v-y, z plasty, and diamond-shaped incisions are used in frenectomy procedures.

#### **17.9.1 Labial Frenectomy** (Video 17.1)

In the edentulous state, the abnormal frenal attachment gets irritated by the denture fanges leading to instability. The denture area can be relieved but it may be unaesthetic, so the need for frenectomy arises. Z plasty is used to eliminate the abnormal attachment. Another method is the V- Y procedure but has a disadvantage of creating excessive bulk of tissue at the depth of vestibule. The operative procedure is as follows (Fig. 17.8a, b and c). It is carried under local anaesthesia, but the tissue should not be overdistended. The lip is extended and everted to tense the frenum. The V-shaped piece of tissue is held by tissue forceps or Allis clamp, and an incision is made down to the periosteum on either side of the frenum. Resorbable sutures are preferred since the removal is diffcult in this area. The frst suture should be placed at the depth of the vestibule and should engage the periosteum to prevent the loss of the vestibular depth (Fig. 17.9a–e).

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**Fig. 17.7** Clinical photographs showing (**a**) lingual papillary hyperplasia (**b**) suturing after excision

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**Fig. 17.8** Clinical photographs showing (**a**) abnormal attachment of frenum (**b**) tissue held with mosquito forceps (**c**) suturing

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**Fig. 17.9** (**a**) low attached frenum, (**b**) frenal tissue grasped by forceps, (**c** and **d**) diamond-shaped tissue removal, (**e**) closure

#### **17.9.2 Lingual Frenectomy** (Video 17.2)

If the frenal attachment is near the crest of the lingual aspect, it will displace the denture. So the need for relief of the high attached frenum is needed. This procedure can be done under local anaesthesia or general anaesthesia (Fig. 17.10a– d). When local anaesthesia is used, bilateral lingual nerve block and infltration are used. The tongue is grasped with traction sutures or forceps and the attachment of frenum to the ridge is cut and the wound is closed with sutures. In

**Fig. 17.10** (**a**) High attached lingual frenum, (**b**) excision of frenum, (**c** and **d)** closure

some, a more extensive procedure is needed. Here, a transverse incision is made between ventral aspect of tongue and caruncle of submandibular duct. Sectioning of some fbres of the genioglosus muscle may yield greater degree of freedom. Diamond-shaped defect is closed with interrupted sutures. Postoperative pain is managed by analgesics and oedema controlled by steroids. There may be some ecchymosis in the foor of the mouth.

#### **17.10 Ridge Extension Procedure**

They are defned as the procedures surgically designed to uncover the existing basal bone of the jaw by repositioning the overlying mucosa and muscle attachments to an inferior position in mandible or to a superior position in maxilla. This will enable to accommodate the larger denture fanges, thus contributing to stability and retention (Tables 17.1 and 17.2).

#### **17.10.1 Vestibuloplasty [Sulcoplasty, Sulcus Extension]** (Box 17.4)

The reduction or obliteration of the sulcus is caused by [1] resorption of the alveolar process, [2] abnormally high muscle attachment in mandible or low on the maxilla, [3] scar tissue resulting from trauma or infection from the contiguous soft tissue.

Vestibuloplasties are carried out in mandible and maxilla. In mandible, both labial and lingual vestibuloplasties are performed. Stability of a denture can be improved by deepening the mandibularsulcus, generating more attached tissues over the functional ridge, and permanently maintaining the

#### **Table 17.1** Mandibular ridge extension procedures

improved vestibular depth. Mandibular vestibuloplasty is carried out to predictably increase and maintain the functional alveolar ridge.

Preoperative preparation of the vestibuloplasty patients includes history, clinical examination, and suitable radiographs. Radiographs, especially orthopantomograph, help to evaluate the ridge height. The commonly performed ones are discussed in this section.

### **17.10.2 Transpositional Flap Vestibuloplasty [Lip-Switch Procedure]**

The credit of this procedure goes to Kazanjian [21], later modifed by many in the literature. Kethley and Gamble [45] modifcation fnds more acceptance in the literature. The selection criteria for this procedure are the minimum bone height of 15 mm between the mental foramen areas.

**Box 17.4 Other Historically Relevant Vestibuloplasty Methods**


#### **17.10.2.1 Procedure**

The technique involves the administration of local anaesthesia followed by mucosal incision. The mucosal fap is elevated and pedicled near the crest of the ridge (Fig. 17.11a and b). An incision is placed near the superior portion of the periosteum. A supraperiosteal dissection is carried in the inferior direction, thereby removing the attachments of the muscular and connective tissues to the indicated vestibular depth. The labial periosteal margin is sutured to the incised lip mucosa. This is followed by the suturing of the pedicled fap to the periosteum at the depth of the vestibule.

#### **17.10.3 Mandibular Vestibuloplasty with Grafting**

Indicated in cases where the lip switch procedure is not possible due to the inadequate tissue availability. The options permissible in such cases were either secondary epithelisation or covering the denuded areas with grafts. The former became less popular because of wound contraction leading to the loss of vestibular depth. Here, the desired alveolar height between the mental foramina is not less than 10 mm in contrast to the minimum of 15 mm in lip switch.

#### **17.10.3.1 Procedure**

An incision is placed at the mucogingival junction and a supraperiosteal dissection carried out to the desired vestibular depth. During the dissection, care is taken not to dissect more than half of the mentalis muscle to avoid the chance of

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**Fig. 17.11** Lip switch vestibuloplasty (**a**) Labial mucosa pedicled near the crest of the ridge (**b**) pedicled fap sutured to the depth of the vestibule

the ptosis of the submental tissues referred as 'witch chin'. The margin of the incision is now sutured to the periosteum in the depths of the vestibule. The harvested graft is now placed over the recipient bed after ensuring adequate haemostasis. The graft is contoured to the correct shape, fenestrated, placed, and fxed on the periosteum with the help of stent or by sutures.

The grafts may be harvested from cutaneous or mucosal areas or allogenic in nature. The best sites for skin graft harvesting are medial thigh or caudal to the iliac crest, where fewer adnexal structures are present in the skin. Areas where smaller grafts are needed, mucosal grafts may be considered, which may be taken from the palate or buccal mucosa. Cultured skin grafts are also becoming popular but lack the mechanical and functional elements of the autogenous grafts. The narration of techniques of grafting is beyond the scope of this chapter.

#### **17.10.4 Lingual Vestibuloplasty: Anterior Region**

The severe atrophy of the mandible in the anterior region makes the genial tubercles prominent and affects the stability of the denture by the attached muscles. The exposure of the tubercles and the detachment of the genial muscles are accomplished by the procedure of lingual vestibuloplasty. Initially proposed by Kazanjian [21] and later modifed by Lewis [32], the disadvantage of this procedure may be the loss of tongue function and diffculty in swallowing, which is encountered if more than half of the muscle is removed.

#### **17.10.4.1 Procedure**

Incision is made in the anterior aspect of the crest of the alveolar ridge and subperiosteal fap is elevated. Dissection continued till the prominent genial tubercle with the attached muscle is encountered. The genial muscles are separated from the ridge and the tubercle is trimmed with bur and smoothed with bone fle. The fap along with the muscle is lowered to the desired depth and it is maintained in the new position by stent and extraoral sutures. The exposed area is allowed for secondary re-epithelisation.

#### **17.10.4.2 Lingual Vestibuloplasty: Posterior Region**

If the amount of the resorption is severe that it results in the displacement of the denture by the action of mylohyoid, then lowering of the mylohyoid muscle should be considered. This can be done alone or in combination with labial vestibuloplasty. The amount of the available depth can be assessed by a clinical manoeuvre, by placing a gloved fnger along the lingual side of the mandible and asking the patient to touch the palate with the tip of the tongue. If this action displaces the fnger, lowering the foor of mouth should be considered.

#### **Trauner's Technique** [30]

Incision is made from the retromolar area to the premolar area of the lingual aspect of the alveolar crest. Mucoperiosteal fap is raised and exposes the mylohyoid and the overlying periosteum. Dissection in the supraperiosteal plane is preferred to avoid the chance of the damage of the lingual nerve. The muscle with the fap is lowered to the desired depth. Sutures are passed through the mylohyoid and mucosa and secured to the skin extraorally. The exposed area is allowed for secondary re-epithelisation (Fig. 17.12a–f).

#### **17.10.4.3 Other Variations Include** (Box 17.5)


position. The new position is secured by a stent or a modifed denture. Instead a polyethylene tubing can be also used to maintain the position.

*Edlan* [29]—here, a combination of the lip switch vestibuloplasty and lowering the foor of mouth is accomplished. Incision is made in the buccal sulcus instead of the crest of alveolar ridge. Plastic tubes are used to maintain the depth of the sulcus.

*Hopkin* [48]—mentioned as Hopkin's operation in the literature, it uses the combined modalities like labial vestibuloplasty, submucous sulcoplasty to remove the buccinator insertion and bilateral mylohyoid ridge reduction.

#### **17.11 Ridge Augmentation Procedures**

In atrophic maxilla, the alveolus may be accentuated by different options; earlier, vestibuloplasty was the choice of procedure. But the results achieved were not long lasting because of the continued resorptive process. So, the advent of augmentation came into action. In severe resorbed and atrophic ridges of Cawood and Howell [6] classes IV—VI, augmentation became mandatory. Unfortunately, this area of preprosthetic surgery has gained little attention, possibly there seemed to be no effective operation for ridge augmentation using an extraoral method; moreover, the penetration into the oral cavity during the procedure was deemed tantamounting to failure, as the surgeons are reluctant to perform the elective augmentation of mandible (Table 17.3).

Classifcation of alveolar ridge defciency by Kent et al. [49] acts as a yardstick to identify the ridge nature and the grafting options.


**Fig. 17.12** Lingual vestibuloplasty methods (**a**) Normal, (**b**) Trauner, (**c**) Brown, (**d**) Caldwell, (**e**) Hopkins, (**f**) Edlan

©Association of Oral and Maxillofacial Surgeons of India


#### **Box 17.5 Lingual Vestibuloplasty Techniques**

#### **Table 17.3** Ridge augmentation procedures

Autogenous bone grafting remains the ideal option to rectify the defciency but accompanied by disadvantages like the need for hospitalisation and general anaesthesia, donor site morbidity, extensive surgical procedure, professional expertise and patient compliance.

#### **17.11.1 Inferior Border Augmentation**

The resorption of the mandible has been so extensive that it results in the severely atrophic condition and liable for a pathological fracture. In such a case, augmentation has to be achieved in the inferior border. The procedure was originally proposed by Marx and Sanders [50] and later modifed by Quinn [51]. The procedure carries the advantages of nonobliteration of the sulcus, allowing the placement of the interim denture and making the secondary vestibuloplasty easier. But the procedure carries the burden of an extraoral scar and the chance of altering the facial appearance. Access to the lower border is gained by different ways by different authors. Some literature supports the use of incision used in the neck dissection, viz. a supraclavicular incision. It extends from the anterior border of sternocleidomastoid to the opposite counterpart. According to Sanders [50], a continuous submandibular incision from angle to angle is suffcient. Ridley and Mason [52] proposed the use of three small submandibular incisions connected by subperiosteal tunnels. The latter is opposed by Sanders [50] for the high chance of resorption by the pressure on the graft. Dissection is carried out to expose the inferior border of mandible. Two ribs of 15 to 20 cm long are harvested and bent to adapt the shape. Three or four transosseous holes are drilled in the lower border of mandible and wires are passed through these holes. One rib is placed against the lingual aspect and the other abutted against the buccal aspect. The space between the ribs is packed with available cortical chips. Ribs are secured in place by interosseous wires in circumferential pattern. Closure is achieved in layers and pressure dressing is applied. The narration of the technique of graft harvesting is beyond the limit of this chapter.

#### **17.11.2 Superior Border Augmentation**

The superior border enhancement is needed [53] in cases where the resorption is so severe that the height of the mandible is insuffcient to accommodate the prosthesis or in cases where the patient suffers from pain during mastication, secondary to the pressure on the mental neurovascular bundle (Fig. 17.13a and b).

Recipient site is prepared and the mucosa is infltrated with local anaesthetic solution containing epinephrine to achieve haemostasis. Crestal incision from the retromolar area to the opposite retromolar area is made and mucoperiosteal fap is raised. Care to be taken to avoid the mental nerve if it is near the superior border. Depending on the position, it may be lowered or freed. The existing superior border is exposed and prepared to receive the graft. The lingual fap is refected to the level of the mylohyoid muscle. Davis and colleagues [54] described the technique of ridge augmentation, which uses two rib grafts of 15 cm. The ribs may be adjacent or alternate. One rib may be contoured by vertical scoring on the inner surface or by bending. Leake [55] recommends splitting the rib longitudinally and then bending it with forceps. The second rib is cut into pieces and packed against the solid rib. Before the placement of the rib, the superior aspect of the mandible is already prepared and suited to receive it. The posterior aspect of the rib should be in contact with mylohyoid shelf, slightly on the lingual aspect of the ramus. The ribs are fxed by three interosseous wires, one placed through each mylohyoid shelf and the other in the anterior region in the midline. Flaps returned to cover the graft.

#### **17.11.3 Interpositional Grafting**

Concept of placing bone grafts between the osteotomised segments of the mandible was initially proposed by Barros saint and Pasteur [56] and later experimentally proved by Danielson and Nemarich [57]. The horizontal osteotomy is achieved by an incision made inferior to the crest of the ridge. The length of the incision is determined by the area to be augmented. Incision is designed from the retromolar area to the other. A buccolabial mucoperiosteal fap is raised and the fap is greatly undermined to get adequate coverage of the graft. Issues are left untouched to ensure the patency of the vascular supply. The horizontal osteotomy is made by burs and osteotomes, and precise osteotomy is obtained by use of saws. The cut may be placed either above or below the canal, depending on the proximity to the inferior border. Transosseous holes are drilled in the lower and upper segments. The harvested graft is interposed between the osteotomised segments and stabilised by the wires. The fap is returned and approximated with sutures (Fig. 17.13c and Table 17.4).

#### **17.11.4 The Visor Osteotomy and Modifed Visor**

The procedures of vestibuloplasty and foor of the mouth lowering may not be always successful to provide a stable and adequate basis for the prosthesis. The situation of the reduced vertical height needs to get addressed. Harle [58] published a report of an original and promising method to augment the alveolar ridge by means of a pedicled bone

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 17.13** (**a** and **b**) Superior border augmentation, (**c**) Interpositional grafting

#### **Table 17.4** Mandibular ridge augmentation procedures

graft. This procedure possesses less danger of infection and rejection of the transplant and of resorption by remodelling processes. The muscles and periosteum in the labial side are refected and the mandible in the frontal region is osteotomised and split in the length. The mobile lingual fragment is slid upwards, together with the adherent soft tissue, and fxed to the basal part of the mandible by intraosseous and perimandibular wiring. Bosker [59] improved this method by combining the osteotomy and the vestibuloplasty and lowering of the foor of the mouth in a one-stage procedure.

The advantage of this modifed technique of Bosker [59] is it needs only single operation and hospitalisation of the patient, the prosthesis can be made in 4–6 weeks sooner, and the operative procedure is simpler.

Sladen and peterson [60] describe the body sagittal osteotomy and raising the lingual cortical portion of the mandible without detaching the lingual soft tissues for the intact vascular pattern. The raised lingual ridge is positioned in the new place, while the buccal counterpart is augmented with cancellous marrow. This procedure is now referred to as visor osteotomy in the literature.

The incision and the mode of raising the mucoperiosteal fap is essentially the same as that used in the horizontal osteotomy as described earlier. Sagittal cut is made between the buccal and lingual cortical plates from the third molar to the opposite third molar area. Precise cutting is achieved by the use of oscillating and reciprocating saws. The lingual segment, which is pedicled to the mylohyoid, digastrics and genial musculature and the soft tissues, is elevated vertically and fxed in the preplanned position with wires through the transosseous holes. The lateral aspect of the elevated segment may be flled with the cancellous bone to compensate the height defciency created by the vertical repositioning. The fap is returned and wound is closed by sutures.

#### **17.11.5 Graft Materials**

Iliac bone crest and rib have traditionally been applied to augment the jaws. Boyne [61] suggested a bone regeneration method, which employs a vitalium mesh tray containing haematopoietic bone marrow encased in a nylon-reinforced Millipore flter. The flter prevents the connective tissue elements accessing the defect and thereby enhances the osseous regeneration. The concern regarding the graft material is the resorption shrinkage in the future. Many attempts are done by surgeons to minimise the resorption shrinkage of the grafted bone. Danielson and Nemarich [57] advocated the subcortical insertion of bone graft. Farell [62] and associates went ahead with interpositional bone graft with simultaneous vestibuloplasty. Sanders and Cox [50] proposed the use of inferior border rib grafting for augmentation. Notched rib can be contoured to the arc of the mandible, but 50% loss by shrinkage is a great disadvantage with rib. The literature suggests the use of pure cancellous iliac graft, iliac cortical cancellous sectional grafts with appropriate immobilisation showing excellent healing even in the event of occasional incision dehiscence.

#### **17.11.6 Augmentation with Synthetic Graft Materials**

A myriad of materials is used for the augmentation of the atrophied ridge. It consists of resorbable and nonresorbable materials. The former fnds its application in periodontal pockets, while the latter is extensively used in the management of alveolar atrophy. Hydroxyapatite, a calcium phosphate material with physical and chemical attributes, is nearly similar to dental enamel and cortical bone has been successfully using for decades. Studies by Kent et al. [49] and Drobeck et al. [63] illustrate the usage. Kent et al. [49] used hydroxyapatite in combination with corticocancellous autogenous bone for augmentation. This combination provides additional strength to the mandible as advised by Jarcho et al. [64]. Though block forms are used by Frame and Brady [65], the granular forms also get used in the augmentation process as guided by Kent et al. [51]. When anterior mandible needs augmentation, a single midline vertical incision is used, while for the complete augmentation of mandible, bilateral vertical incisions anterior to mental foramen are used. A subperiosteal tunnel is formed, which can be assessed by a dental mirror and the syringe loaded with graft material is inserted through the tunnel and delivered in place. After the tunnel is flled with graft material, the incision is closed with interrupted or horizontal sutures.

In maxilla, a single vertical incision in midline may be suffcient, but in many cases bilateral incisions in the canine regions may accommodate more amount of graft material. It is similar to the procedure in mandible except for the palatal dissection, where the ridge width is needed. Denture can be placed at about 1 month in cases where augmentation is carried out by hydroxyapatite alone or 6–8 weeks in which both hydroxyapatite and bone are used together. If vestibuloplasty is planned, Kent [49] advocated a waiting period of 8 weeks after graft placement.

#### **17.12 Conclusion**

The art of designing the soft- and hard-tissue framework for the smooth placement of the prosthesis is a challenging task. This task is achieved by the meticulous planning and execution of the planned presurgical procedures in a systematic manner. The intimidating impressive trends of implantology might have downsized the charm of preprosthetic surgery, yet in certain avenues the preprosthetic surgical manoeuvres become inevitable. The magnitude of vestibuloplasty and ridge augmentation procedures associated with the anticipated patient discomfort should not demote the benefts of preprosthetic surgery in deserving patients, where they suffer from pain or embarrassment by a juggling ill-ftting denture. Such corrections may alter their present situations and successful denture wearing is ensured. So it is not possible to completely thwart or baffe the procedures belonging to the preprosthetic surgery as an obsolete one.

**Acknowledgments** Fig. 17.6 - Suvy Manuel.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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**Part VII**

**Dental Implantology**

## **Basics of Dental Implantology for the Oral Surgeon**

Supriya Ebenezer, Vinay V. Kumar, and Andreas Thor

#### **18.1 History and Evolution of Dental Implants**

Modern implant dentistry started more than 50 years ago when Dr. P.I. Brånemark, a Professor from the University of Gothenburg (Sweden), discovered in rabbit studies that titanium chambers placed in the fbula became frmly anchored in bone and could not be removed. Later, this direct bone-toimplant contact was termed osseointegration [1]. He demonstrated that titanium was structurally integrated into living bone with a high degree of predictability and without longterm soft-tissue infammation or fxture rejection. He introduced a two-stage threaded root form pure titanium implant that was placed in patients in 1965. Therefore, Prof. P.I. Brånemark is recognized as the most important pioneer in modern implant dentistry.

The second pioneer is Prof. Andre Schroeder from the University of Bern (Switzerland) experimented with prototype dental implants in the early 1970s and could demonstrate frst osseointegration in nondecalcifed histologic sections [1]. Both pioneers with their teams, independent of each other, performed several preclinical and clinical studies to establish the current scientifc basis for dental implantology. This was the start to successful osseointegration in dentistry.

Between the 1970s and the 1980s, companies presented different implant designs such as the Tübingen implants made of aluminum oxide, the IMZ titanium plasma-sprayed

S. Ebenezer (\*)

V. V. Kumar · A. Thor

surface, and the American Core vent implants made of titanium aluminum vanadium alloy [1]. However, based on the research from Albrektsson, commercially pure titanium became the material of choice. One-piece implants slowly evolved to two-piece implants to provide prosthetic fexibility.

Over the next 15 years, implantology shifted from the treatment of fully edentulous patients to the treatment of partially edentulous patients as well. Prosthetic components for the rehabilitation of different edentulous situations emerged, and different surgical techniques and regenerative materials were developed to improve the hard and soft tissues around implants. Concepts of implant placement, loading, occlusion, and maintenance evolved. Progress was made in implant surface technology, which permitted the use of shorter and narrower implants and reduced loading time [2]. Over the last decade, development has included strategies to provide long-term stability with optimum functional, esthetic, and phonetic results along with reduced complications. Advanced diagnostic aids, such as cone beam computed tomography (CBCT), enabled proper assessment of the surgical site and surgical planning to provide better outcomes. Devices to examine implant stability objectively, using resonance frequency analysis, improved the quality of treatment provided. Digital technology is increasingly being incorporated to improve accuracy, minimize invasiveness, and fulfll esthetic demands. On the material front, ceramic implants and implants using alloys of increased strength have been introduced [2]. The feld of implantology is a fastevolving one where the clinician has to be constantly updated to keep pace.

### **18.2 The Concept of Osseointegration**

Titanium implants could become permanently incorporated within bone, such that the two could not be separated without fracture [3]. Osseointegration was the term given to this con-

**<sup>18</sup>**

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_18) contains supplementary material, which is available to authorized users.

Department of Oral Surgery and Stomatology, University of Bern, Bern, Switzerland

Department of Maxillofacial and Plastic Surgery, Uppsala University Academic Hospital, Uppsala, Sweden

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 385

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_18

tact and refers to a direct bone to metal interface without interposition of soft tissue seen at the optical microscope level. Osseointegration is defned as "a direct structural and functional connection between ordered living bone and the surface of a load-carrying implant." [4]

#### **18.2.1 The Biological Process of Osseointegration**

The cellular response after implantation depends on implant surface characteristics, the stability, and heating injuries of the host bone. Bone healing around implants involves a cascade of cellular and extracellular biological events (similar to fracture healing) until the entire implant surface is embedded in bone.

The frst biological component to contact the implant surface is blood and blood cells from the surrounding vasculature. These blood cells are activated and release cytokines and other growth and differentiation factors on and around the implant. Platelets undergo biochemical and morphological changes due to contact with the implant surface and undergo adhesion, spreading, and aggregation. They induce phosphotyrosine, increase intracellular calcium, and cause hydrolysis of phospholipids to form a fbrin matrix that regulates cell adhesion and binding of minerals. This matrix is a calcifed afbrillar layer consisting of osteoid and lamina limitans (organic layer) that is rich in calcium, phosphorus, osteopontin, and bone sialoprotein [5]. This matrix acts as a scaffold for osteogenic cells to migrate and differentiate to form osteoid and trabecular bone (osteoconduction), which will ultimately remodel to form lamellar bone around the implant surface. The ability of the implant surface to retain fbrin attachment during the initial phase is critical in determining if the migrating cells reach the fbrin clot. Roughened surfaces promote osteoconduction. The chemistry of the implant surface also infuences osteoconduction, and for example, hydrophilic implant surfaces have increased osteoconduction as compared to hydrophobic surfaces.

Peri-implant osteogenesis occurs in two ways with the native bone as described by Osborn and Newesley in 1980.


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 18.1** Histology of osseointegration. Osseointegration is defned as the direct apposition of bone onto the titanium implant surface as seen in this histology section

implant surface that has attracted osteogenic cells slowly has calcifed afbrillar tissue forming into it. Blood vessels and mesenchymal cells fll up the spaces in between. Cement lines of poorly mineralized osteoid separate the areas of resorption and initiation. Woven and trabecular bone fll the initial gap and provide biological fxation to the implant at about 10–14 days postsurgery. However, the random orientation of the collagen fbers gives it reduced mechanical properties as compared to lamellar bone. This biological fxation differs from primary stability obtained at implant placement and is commonly seen with rough implant surfaces. Woven bone is slowly remodeled in response to stress and mechanical loading and replaced by lamellar bone until it reaches a high degree of mineralization. At approximately 3 months postimplant placement, the bone is a mixture of both woven and lamellar matrix [6].

(Figure 18.1: histology showing adequate osseointegration)

#### **18.2.2 Assessment of Osseointegration**

An implant is considered to be osseointegrated when an implant is in direct contact with the bone, and there is no relative movement between the implant and the bone. In other words, osseointegration is expressed clinically as longterm state of stability of the implant in the vital bone. According to Albrektsson (1985), a loaded implant is considered osseointegrated if the average surface contact with bone is a minimum of 50% [7]. Initially, the strength of the interface (initial stability) between bone and implant is high due to mechanical stability; however, it decreases over the next few weeks due to bone remodeling and then increases again due to new bone formation (secondary stability). The stability also depends on biophysical stimulation and the healing time. To clinically evaluate osseointegration mobility tests, standardized radiographs and Resonance Frequency Analysis (RFA) are used [6].

#### **18.2.3 Factors that Determine Osseointegration**

There are many factors that infuence the formation and maintenance of bone at the implant surface [3, 6].


layer protects against corrosion and also helps in calcium and phosphate ion exchange at the surface. Surfaces were modifed to increase microroughness and hence the surface area for osseointegration. The additive processes are Ti plasma spraying, hydroxyapatite coating, discrete crystalline deposition (DCD), and electrochemical anodization (to increase the TiO2 layer). These processes increased the surface area for bone contact with the implant surface, which increases the osseointegration. Subtractive processes to increase microroughness were also utilized in several implants to increase the microroughness, which also contributed to better osseointegration. Sandblasting, acid etching, and laser modifcation are some of the subtractive processes. Sandblasting produces a macrotexture, which is converted to a microtexture by acid etching. This surface promotes greater osseous contact at earlier time points compared to plasma-sprayed coated implants. Titanium surfaces were treated with fuoride, and this roughened the surface and demonstrated better bone anchorage, as compared to unmodifed titanium surfaces [10]. Research is currently oriented toward making biomimetic implant surfaces that shorten healing times and provide better bone to implant contact [11].


#### **18.3 Comparison Between Implant and Tooth Surface** [16]

Figure 18.2a, b, and c show the differences between implants and tooth.

Implant prosthetics provide highly esthetic results that mimic the natural tooth; however, certain critical differences in the structure of the peri-implant tissues and periodontal structures exist. The lack of a periodontal ligament is the most striking difference; this absence means that the connec-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 18.2** (**a**, **b**, and **c**) show diagrammatic representation of the biological differences between an implant and a tooth in longitudinal section

tion between the implant and the surrounding bone is not as resilient as that around the tooth. Implants, unlike teeth, do not intrude or migrate to compensate for premature contacts, and hence, the repercussions of occlusal disharmony can be detrimental. Implants lack proprioception and refex function due to the absence of the periodontal ligament. This is critical when implant-supported prosthesis opposes each other. Implants do not supraerupt with time and hence lead to occlusal disharmonies when used as replacements for young and growing individuals. Hence, any form of overload on an implant causes fracture in the prosthesis, the implant structure, or bone loss surrounding the implant.

#### **18.4 Types of implants**

	- (i) Pure titanium and titanium alloys:

Commercially pure titanium(CpTi) was the material of choice due to its high biocompatibility and resistance to corrosion. CpTi is available in Grades I to IV; however, to improve the mechanical properties, alloys of titanium such as Ti-6Al-4 V have been used. Several alloys with Ti, such as Ti-Au, Ti-In, Ti-Sn, Ti-Pb, Ti-Cu, and Ti-Nb, have been tested. A Ti-Zr alloy (Titanium 83–87% and Zirconium 13–17%) is presently very popular as it has mechanical properties superior to those of the previously used alloys as well as high corrosion resistance.

(ii) Zirconia implants:

These implants are made from the oxide form of Zirconia (ZnO2) and are "ceramic" implants that have high biocompatibility and ability to osseointegrate. In addition to the high mechanical properties, they were introduced especially for esthetic areas and in patients who maybe potentially allergic to titanium. The drawback of these implants is that most of the designs are one piece and only a few systems have two-piece implants. The idea of zirconia implants seems to be potential; however, no long-term evidence for its success exists at this time.

	- (i) Screw-type implants:

Threads in screw-type implants increase the surface area for osseointegration. Threads help in stabilization by improving bone to implant contact and in stress distribution. There are several differences in thread shape, thickness, pitch, thread-face angle, etc. based on the manufacturers. These are the most widely used and documented form of implants.

(ii) Cylindrical and tapered implants:

Based on the shape of the implant body, implants are considered cylindrical (with parallel walls) or tapered. When the endosseous part of a cylindrical implant narrows in diameter toward the apex, an implant is considered tapered. The taper can be in the cervical, middle, or apical parts only or continuously taper from the cervical to the apex. Tapered implants were introduced to improve initial stability in less dense bone.

(iii) Platform switch implants:

When a smaller-diameter abutment is used on a larger-diameter implant collar, the implantabutment junction shifts inward toward the central axis of the implant. This is considered to be a major factor in limiting crestal bone resorption especially in esthetic sites.

(iv) Bone-level and tissue-level implants:

Tissue-level implants have a butt joint transition from the smooth collar to the rough portion, and this transition zone is placed almost level with the bony crest. This design is generally used for nonsubmerged healing; here, the implant-abutment microgap is away from the bony tissues. Bone-level implants have minimal/no smooth collar and are completely microrough, and they are inserted almost level with the bone. This is meant for submerged healing, and here, the implant-abutment microgap is adjacent to the bone crest. In these implants, platform switch is used to limit crestal bone resorption.

	- (i) Machined (Brånemark surface):

These are the minimally rough implant surfaces made of turned CpTi, which were not further treated. These were used earlier and are also well documented. However, with a need to increase the surface area for bone attachment especially in less dense bone and to reduce time for osseointegration, these surfaces were modifed. Smooth surfaces had an advantage of reduced attachment of plaque bioflms.

(ii) Textured/rough surfaces:

The smooth surfaces of the implants were altered to a textured surface to increase the surface area for osseointegration. They were classifed as macro-, micro-, and nano-sized topologies based on the scale of roughness [17, 18]. Macrotopographic profles of dental implants had a surface roughness in the range of millimeters to microns. This roughness was directly related to geometry of the implant, threaded screw, and macroporous surface treatment. Microrough topographies were in the range of 1 and 10 μm. A profle roughness average of 1–2 μm is optimal for osseointegration [19]. The surfaces were altered by different processes. Additive processes resulted in these popular types—sintered porous surfaces, titanium plasma sprayed, and hydroxyapatite plasma sprayed. Subtractive processes also created a rough texture, and they were sandblasting, acid etching, and laser alteration. Rough surfaces were demonstrated to have better bone to implant contact, which resulted in better osseointegration [20, 21]. Over the years, nanotopographies have been explored. Compaction of nanoparticles (such as titanium dioxide), molecular self-assembly method, and acid/alkali treatments or peroxidation for nanoparticle deposition have been advocated to increase nanoroughness.

	- (i) Extra-short: 6 mm in length or less.
	- (ii) Short: From more than 6 mm to less than 10 mm.
	- (iii) Standard: From 10 mm to less than 13 mm.
	- (iv) Long: More than 13 mm.

Although traditionally, the concept was to get implants "as long as possible" for good osseointegration, the current trend with improved surfaces is "as long as needed". The introduction of shorter implants is to reduce the invasiveness and reduce morbidity.

	- (i) Extra narrow: Less than 3.0 mm.
	- (ii) Narrow: From 3.0 mm to less than 3.75 mm.
	- (iii) Standard: From 3.75 mm to less than 5 mm.
	- (iv) Wide: 5.0 mm or more.

Earlier, implants with diameters as wide as the tooth being replaced were used. Changing concepts of jumping gap, preserving the buccal cortical plate, and optimal 3-dimensional position coupled with improved surfaces encouraged slightly narrow diam-

#### **Box 18.1 Types of Implants**

*Implants can be classifed as follows:*

	- (i) Titanium and titanium alloys
	- (ii) Zirconia
	- (i) Screw type implants
	- (ii) Cylindrical, apically tapered, and fully tapered
	- (iii) Platform-switch implants
	- (iv) Bone level vs. tissue level implants
	- (i) Machined (Brånemark surface)
	- (ii) Textured/rough surfaces
	- (iii) Hydrophobic/Hydrophilic surfaces

eters as compared to previous trends. Extra-narrow and narrow-diameter implants are used in defcient sites to minimize invasiveness and morbidity.

#### **18.5 Preoperative Examination of Potential Implant Patients**

#### **18.5.1 Clinical Examination**

Before implant treatment, a careful analysis should be conducted. This includes patient's current health status and medications and details of past medical history and medical treatments.

Patients should be questioned about parafunctional habits, oral hygiene, and personal habits such as tobacco, alcohol, and drugs. The compliance, motivation, attitude, understanding, and expectations of the patient are important for optimal treatment outcome.

Clinical examination should include extra-oral examination, i.e., lip line, lip competence, and temporomandibular joint. Intraoral assessment should include assessment of the edentulous space, occlusion, status of adjacent and opposing teeth, overall periodontal status, presence of other implants and restorations, shape of the teeth, gingival biotype, and any other local factor that may impact the success of the treatment.

Diagnostic study models and intraoral clinical photographs are essential for documentation as well as for the further assessment of spatial and occlusal relationships.

©Association of Oral and Maxillofacial Surgeons of India

#### **18.5.2 Radiographic Examination**

Figure 18.3a and b show examples of two-dimensional and 3-dimensional examination of the maxillary sinus.

Radiographic examination should be done in the evaluation phase to determine the status and anatomy of the underlying bone, if implant placement is possible and if any other surgical procedures are required before implant placement. A 2-dimensional radiograph of the area is desired; however, this is insuffcient to provide a detailed 3-dimensional assessment of the site. Hence, the radiograph of choice is the Cone Beam Computerized Tomography (CBCT) as it provides a detailed three-dimensional analysis of the edentulous area along with the neighboring anatomical structures. With the software for CBCT, it is possible to measure accurately the dimension of the site and distances from critical structures and accurately plan which implant dimension would be appropriate. CBCT imaging also gives us information on which sites require augmentation and if so the location and extent required.

### **18.5.3 Correct 3-Dimensional Position for an Implant**

For the site of implant placement, the available space should be evaluated in three dimensions, i.e., mesiodistal, buccolingual, and apicocoronal dimensions. A graduated periodontal probe can be used for clinical measurements; however, this information is best recorded from imaging techniques such as CBCT. While evaluating the available space, factors such as proximity to adjacent anatomical structures such as maxillary sinus, mandibular nerve, nasal foor, adjacent tooth roots, etc. should be considered.

The minimal space required for an implant depends on the size of the implant to be used (in terms of length and diameter), whether the implant is placed adjacent to two natural teeth or adjacent to an implant and the apicocoronal distance in the bone.

1. Implant adjacent to a natural tooth: Buser et al. (2004) suggested a concept for correct 3-dimensional implant placement [25]. They designated zones called as comfort zones (which is the ideal position for an implant) and danger zones (in which implants should not be placed). This was defned in three directions mesiodistally, coronoapically, and orofacially. (Figure 18.4 a, b, and c show diagrammatic representation of the correct positioning of implants in a 3-dimensional manner). The ideal mesiodistal distance between a natural tooth and the shoulder of an implant is 1.5 mm [25]. The zone up to 1–1.5 mm from the adjacent teeth on either side was the danger zone. Between the danger zone was the comfort zone that is safe for implant placement [25]. For example, if an implant of 4.1 mm in diameter is placed between two natural teeth, the minimum mesiodistal distance available should be 7 mm (to allow 1.5 mm between the implant and the natural teeth on either side). If placed too close to the adjacent teeth, it causes bone loss. In the orofacial dimension, the implant shoulder is positioned palatal to the incisal edge of the future restoration (or 1 mm palatal to the point of emergence of the

**Fig. 18.4** (**a**, **b**, and **c**) diagrammatic representation of ideal placement of a single implant in green shadow and unideal positions that could lead to complications (in red shadow). (**a**) ideal coronoapical position, (**b**) ideal mesiodistal position, and (**c**) ideal orofacial position

**Fig. 18.4** (continued)

adjacent teeth). The oral aspect has a danger zone as well, indicating that an implant should not be placed too far orally to prevent the use of a ridge lap restoration. Too far facially will result in increased mucosal recession. In the apicocoronal direction, the apex of the implant should be at least 1-2 mm away from any anatomical structure such as nerve, sinus, or tooth roots. Also, in the shoulder of the future implant should be at least 1 mm apical to the cementoenamel junction of the adjacent teeth to allow for a proper emergence profle [25]. Placing an implant too deep will result in too much countersinking, diffcult handling, and facial mucosal recession. Placing an implant too superfcially will cause the metal margin to be visible and improper emergence profle. In addition to this, the ideal facial bone thickness should be 2 mm [26] and the lingual bone thickness should be 1.5 mm. Hence, for a 4.1 mm implant, minimum orofacial distance should be approximately 7.5 mm. Also, to prevent the appearance of black triangles, the apicocoronal distance from the interdental contact point to the crest of bone should not exceed 5 mm. (Figure 18.5a shows diagrammatic representation of the distance between interdental contact point and the crest of bone, for adequate papilla preservation).

2. Implants adjacent to each other: The mesiodistal distance between the implants should be at least 3 mm [25, 26]. This is critical to allow adequate interimplant bone and hence the formation of a soft tissue papilla overlying the bone. The other requisites for mesiodistal, orofacial, and apicocoronal dimensions, as previously mentioned, apply in addition. (Figure 18.5b shows diagrammatic representation of the distance between interdental contact point and the crest of bone, for adequate papilla preservation).

When the space for an implant of a particular diameter is less than ideal, a decision should be made either to augment the site with bone or to choose an implant of smaller diameter. However, this decision requires clinical expertise as augmentation procedures are technique sensitive and using smaller diameter implants depends on evaluation of the occlusal forces in the area. The interocclusal distance also needs to be evaluated prior to implant placement as it determines the choice of prosthetic rehabilitation of the implant. If the interocclusal distance is reduced,

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 18.5** (**a** and **b**) diagrammatic representation of the critical dimensions in implant placement in relation to interdental papilla. (**a**) The height (H) of the interdental contact from the crest of the interdental alveolar bone should not be more than 5 mm for obtaining adequate

the choice would be to use a screw-retained prosthesis over a cement-retained one. Screw-retained prosthesis, however, is the more preferred technique due to ease in retrievability and cleansability.

The amount of keratinized tissue in the site should also be evaluated before surgery as this determines the location of the incision. Ideally, a band of at least 2 mm (minimum 1 mm) keratinized tissue should surround the implant, and this is critical to the long-term success of the implant. If this is not achievable, procedures to augment the keratinized mucosa should be planned. Keratinized mucosa is necessary as it provides a physical barrier to oral plaque and to the forces of mastication as compared to nonkeratinized mucosa [27].

#### **18.6 SAC Classifcation**

The International Team for Implantology (ITI) proposed a classifcation of sites for implant placement based on the analysis of several factors [28].

Based on these factors, sites for implant surgery could be classifed as straightforward (S), advanced (A), and complex (C).

interdental papillary morphology. (**b**) The interimplant distance (D) should be at least 3 mm for obtaining adequate interdental papillary morphology

This provides the clinician an assessment of the site for implant placement before the surgery is planned and is based on the level of expertise of the clinician who can either treat or refer to a specialist.

The determinants of the classifcation are.


The general modifying factors are.

1. Clinical competence and expertise: The SAC Classifcation for a case type is independent of the clinician's skill and competence. A Straightforward case is an uncomplicated procedure, and a Complex case is the one that is diffcult to manage.


Tables 18.1, 18.2, and 18.3 show the esthetic, surgical, and restorative modifying factors to be considered during implant treatment planning and execution.

**Table 18.1** The esthetic modifying factors are determined by the Esthetic Risk Assessment (ERA)


Adapted with permission from Dawson A, Chen S, Buser D, Cordaro L, Martin W, Belser U. The SAC Classifcation in Implant Dentistry. Editors: Dawson A, Chen S. Quintessence Publishing Co. Ltd. 2009

The above-mentioned modifers have to be considered for every implant case during the assessment and planning phase of treatment. Risks can be identifed prior to treatment, thus minimizing complications. To classify as Straightforward, Advanced, or Complex for a specifc case, the specifc features of the case can be matched with the descriptions in the tables. The level that best matches the factors of the individual case will provide the SAC Classifcation for that case.

The fnal treatment plan including additional surgical procedures (if required) should be formulated after accurate diagnosis and consideration of the patient's systemic and local factors, bearing in mind the requirements of the patient.



Adapted with permission from Dawson A, Chen S, Buser D, Cordaro L, Martin W, Belser U. The SAC Classifcation in Implant Dentistry. Editors: Dawson A, Chen S. Quintessence Publishing Co. Ltd. 2009



Adapted with permission from Dawson A, Chen S, Buser D, Cordaro L, Martin W, Belser U. The SAC Classifcation in Implant Dentistry. Editors: Dawson A, Chen S. Quintessence Publishing Co. Ltd. 2009

#### **18.7 Implant Solutions for Diferent Edentulous Situations**

Implants can be used as replacement options for all kinds of edentulous situations varying from single tooth gaps to completely edentulous jaws (Figure 18.6 shows an example where an implant has been used for the restoration of single tooth, and 7b shows an example where implants have been used for the replacement of the edentulous upper and lower jaws). The treatment plan varies in complexity as the number of teeth replacements increases, if it is an esthetic site or not and if the opposing dentition is implant-supported or not and depending on the occlusal load. As few as possible but as many as needed should be the key when placing implants. The selection of the size of the implant (length and width) and the number of implants especially in areas of poor bone quality is important for providing the correct solution.

For large edentulous spans, it is preferable to use as many implants as required, to support the occlusal forces in that area. Cantilever prosthesis on implants has to be used with discretion and is limited to areas of low occlusal demand. It is not preferable to splint implant with natural teeth as

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 18.6** (**a**) shows an example where an implant has been used for the restoration of single tooth, and (**b**) shows an example where implants have been used for the replacement of the edentulous upper and lower jaws

implants cannot intrude with force like natural teeth. Longspan bridges on implants are not advisable in soft bone, e.g., in the completely edentulous maxilla, a fxed prosthesis can be given on six implants, while in the mandible, the same can be achieved with only four implants. For removable prosthesis, in an edentulous maxilla, four to six are suffcient, while in the edentulous mandible, the similar prosthetic solution can be achieved with two to four implants. There are several concepts of implant replacement for long edentulous spans and several designs of implants indicated for specifc types of sites; however, the details of these are beyond the scope of this chapter.

#### **18.8 Timing of Implant Placement Postextraction**

#### **18.8.1 Hard and Soft Tissue Alterations Postextraction**

Studies in beagle dog revealed that postextraction, the bundle bone resorbs as the blood supply to this bone is compromised due to tooth extraction [29, 30]. This results in vertical bone loss in both facial and lingual walls of the socket, but it is more pronounced on the facial aspect as most often it is thinner in width than the lingual wall [30]. In human studies, ridge width reduction of up to 50% occurred during the frst year after tooth loss in premolar and molar sites, and twothirds of the total change took place within the frst 3 months following extraction [31]. Dimensional alterations occurred in both height and width, with approximately 2.6–4.5 mm in width and 0.4–3.9 mm in height being lost in the healed sockets [32]. Histologically, the density of vascular structures and macrophages reduced from 2 to 4 weeks, the osteoclastic activity slowly decreased over a 4-week period, and osteoblasts peaked at 6–8 weeks remaining almost stable thereafter [33]. Thin facial walls seem to be prone for resorption, and sites with facial bone wall thickness of 1 mm or less had vertical bone loss of 7.5 mm (62%) of the original bone height after an 8 week healing period. Patients with thick wall phenotype, having facial bone wall thickness of more than 1 mm, had only about 1.1 mm (9%) vertical bone loss [34]. Also, for single extraction sites, the dimensional alteration occurred mainly in the central mid-facial area of the socket wall, while the proximal areas that had viable periodontal ligament of the adjacent teeth remained nearly unchanged after fapless tooth extraction at 8 weeks of healing [35]. With this pattern of resorption, a thin wall phenotype will develop a two-wall defect, while a thick-wall phenotype will result in a three-wall defect after initial remodeling [34]. Thus, the evaluation of facial wall thickness is critical to predict the future of bone loss prior to extraction [13]. With the above fndings related to the pattern of bone remodeling and the timing of the cellular activity, in thin bone wall phenotypes, it is recommended to allow the initial postextraction remodeling to take place before initiating regenerative procedures. An early implant placement would be recommended for thin bone phenotypes. Immediate implant placement would be recommended only for thick wall phenotypes and thick gingival biotypes where minimal remodeling would be expected.

The soft tissue thickness in maxillary anterior teeth is thin in most patients, ranging from 0.5 mm to 1 mm. This soft tissue thickness has not shown signifcant correlation to the underlying facial bone wall thickness [36]. For single extraction sites, 50% of the soft tissue change occurs within the frst 2 weeks postextraction. The increase in soft tissue thickness signifcantly depends on the underlying bone dimensions. In thick wall phenotypes, the soft tissue dimensions do not signifcantly change. In these defects, the alveolus acts as a selfcontained bony defect and favors the growth of bone-forming cells from the adjacent socket walls. In thin wall phenotypes, the facial bone wall resorbs rapidly and the highly proliferative soft tissue occupies its position. There is a sevenfold increase in soft tissue occupying the crestal area of the socket defect, and this is termed as spontaneous soft tissue thickening [13]. The tissue formed is highly vascularized granulation tissue with fbroblasts migrating into it, some of which differentiate into myofbroblasts that are involved in the thickening phenomenon. At 8 weeks, there is a peak in endothelial cell density, BMP-7, and osteocalcin expression, indicating that the molecular and cellular mechanisms that regulate new bone formation also infuence the soft tissue thickening. The clinical implications of this soft tissue thickening are that, after an 8 week healing period, the soft tissues are suffciently thickened and provide increased keratinized tissue in the site that allows for primary closure favoring bone regeneration. With this thickened soft tissue, there is no requirement for additional soft tissue grafts. However, this soft tissue thickening can mask the underlying bone defect, often misleading the clinician while selecting the appropriate treatment protocol [37].

#### **18.8.2 Concept of Timing for Implant Placement**

Implant placement can be classifed based on the timing of implant placement. According to the ITI Consensus Conferences in 2003 and 2008, it is classifed as Type 1, Type 2, Type 3, and Type 4 implant placement [38].

#### **Box 18.2 Concept of Timing for Implant Placement**


The choice of timing of implant placement depends on several factors. The four options are available to the clinician, who can select the option based on the following criteria, provided that they have the required clinical expertise.

	- (i) a completely intact, thick wall phenotype (i.e., >1mm) facial bone wall at the extraction site
	- (ii) thick gingival biotype,
	- (iii) absence of acute infection at the extraction site, and
	- (iv) adequate volume of bone apical and palatal of the extraction site to allow suffcient primary stability of the implant while placing it in the correct 3-dimensional position.
	- (i) In situations where there is inadequate keratinized tissue, this technique allows an additional 3-5 mm of tissue as the tissues heal spontaneously.
	- (ii) In sites where there is a thin facial bone, the bundle bone spontaneously resorbs and a spontaneous soft tissue thickening takes place to fll the extraction socket.
	- (iii) Acute and chronic infections resolve leaving the future implant site free of infections.
	- (iv) Bone forms in the apical portion of the socket, thus allowing primary stability from the apical bone during implant placement. At the stage of implant placement, a guided bone regeneration procedure with bone graft and membrane is most often required.
	- (i) patients with systemic conditions that require treatment to be deferred, e.g., pregnant patients,
	- (ii) adolescent patients who are too young to receive implants and require the treatment to be deferred, and
	- (iii) patients who are unable to make an early appointment due to personal reasons.

Site-related factors include.


#### **18.8.3 Healing Modality: Concept of Submerged and NonSubmerged Healing**

When an implant is placed, the operator can choose to either submerge the implant (completely enclose it within the healing tissues) or keep it nonsubmerged (implant is visible through the healing soft tissue). (Figure 18.7 shows diagrammatic representation of submerged and nonsubmerged healing).

In the nonsubmerged/one-stage approach, the healing cap/abutment of the implant emerges through the mucosal tissues at the time of fap closure after implant placement. Nonsubmerged implants can be one-piece or two-piece implants. In one-piece implants, there is no micromovement and no microgap between the implant and the abutment. In the two-piece nonsubmerged implants, there is no need for a second surgical procedure to expose the implant for prosthetics; however, the potential of the microgap between the two components exists. This technique is generally preferred for standard implant placement procedures where there is no need to augment the site.

In the submerged/two-stage approach, the healing cap/ cover screw is completely covered with the soft tissue fap after implant placement surgery. The implants are allowed to osseointegrate in a closed environment without loading or any form of micromovement, for a period of time. The submerged protocol is used for implant placement with simultaneous bone augmentation. Following this healing period, the implant is surgically exposed to place the abutment. Both these techniques are well accepted and can be selected based on the treatment plan.

#### **18.9 Surgical Procedure for Conventional Implant Placement**

As mentioned before, the most important step before implant surgery is the analysis of the general patient factors and then the local edentulous site factors. Depending on whether it is an implant replacement for a single tooth, multiple teeth, or a completely edentulous ridge, the planning differs. The

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 18.7** Diagrammatic representation of submerged and nonsubmerged healing

treatment protocol also differs depending on whether it is an esthetic site or not. Single tooth replacements in a nonesthetic site are simpler as compared to multiple teeth replacements in an esthetic site.

For standard implant placement:

	- (a) Initially, a small diamond bur is used to mark the site. The mark created corresponds to the center of the osteotomy and should be in the correct mesiodistal and buccolingual position. This bur is used to make a hole of 1–2 mm deep to create a start point for the pilot drill.
	- (b) The pilot drill is the frst twist drill used to create the osteotomy up to the desired length. Ideally, the length of the osteotomy should be slightly more than the implant so that the implant can be placed slightly subcrestal (to compensate for future crestal bone resorption). Also, the shoulder of the future implant should be 1 mm apical to the cementoenamel junction of the adjacent teeth in esthetic areas to allow for a proper emergence profle. While drilling, the correct axis

should be maintained. The drills should be repeatedly pumped in and out of the osteotomy to expose the bone debris to the water coolants for clearing. If multiple implants are to be placed, a guide pin is used in the frst osteotomy to align the second implant before commencing the second osteotomy preparation.


are placed in 4–0 or 5–0 nonresorbable sutures. Suturing of vertical incisions and papillae is generally done with 5–0 or 6–0 nonresorbable sutures.


(Figure 18.8 shows an example of the surgical phase of single implant placement)

#### **18.10 Concepts of Implant Loading**

An implant loading protocol is the time period between implant placement and the attachment of the prosthesis. The loading protocols have changed over the years, and the ITI Consensus Conferences in 2003, 2008, and 2013 had slight variations in defning them. The current defnition as per the ITI Consensus Conference 2018 is as follows [39]:


#### **Box 18.3 Concepts of Implant Loading**


Patient-related factors such as medical and systemic risk factors, surgical site factors (augmented site), and implant stability as assessed by insertion torque (20–50 Ncm2 ) and resonance frequency analysis (>55 ISQ) are determinants for selecting the loading protocol. Implant design and characteristics also affect the loading protocol, surface modifcation of implants has added to faster healing rates of bone around implants, and hence, the healing period before loading has reduced [23]. Hence, selection of a correct loading protocol is case specifc.

**Fig. 18.8** These series of fgures show steps in implant placement with restoration of a single tooth edentulous space. (**aa**) Preoperative facial view of edentulous space. (**ab**) Preoperative occlusal view of edentulous space. (**ac**) Preoperative master cast with surgical splint. (**b**) Incision and refection of mucoperiosteal fap. (**ca**) Initial drilling. (**cb**) Checking for ideal placement of initial drill with surgical guide, which would lead to *prosthodontically* driven implant placement and a favorable emergence profle. (**cc**) Checking for the depth of implant osteotomy using a depth gauge. (**da**) Subsequent drilling to accommodate the chosen dimension of the implant. (**db**) Subsequent drilling to accommodate the chosen dimension of the implant. (**e**) Implant insertion. (**f**) Placement of healing abutment for transmucosal/ non submerged healing. (**g**) Suturing and wound closure

**Fig. 18.8** (continued)

403

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 18.8** (continued)

#### **18.11 Suggested Reading**

ITI Treatment guides 1–10.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

# **19**

## **Bone Augmentation Procedures in Implantology**

Vinay V. Kumar, Supriya Ebenezer, and Andreas Thor

#### **19.1 Introduction**

Dental implants have been used successfully to rehabilitate patients with edentulousness. For implant dentistry to be successful, the implants have to be placed in an appropriate threedimensional manner that supports the prosthesis adequately. This means that implants have to be placed in a prosthodontically driven predetermined position. This requirement often results in a clinical situation where there is a lack of bone volume to completely embed the implant in an ideal position.

Implants that do not have an adequate amount of bone covering them in all aspects (at least 1.5 mm bone buccal and lingual to the implant shoulder or about 2 mm in aesthetic zones) are at high risk for crestal bone loss with concomitant infammation and infection of the surrounding soft tissues due to exposure and colonisation of the implant surfaces by bacterial bioflms [1]. This in turn results in soft-tissue recession, which leads to further loss of bone and eventually failure of the implant. Hence, bone augmentation is often necessary to ensure adequate bony housing around implants [2].

The most commonly used bone-augmentation surgical procedures are guided bone regeneration (GBR), block bone grafting and maxillary sinus foor elevation (SFE). When deciding to augment, there are multiple sources of bone-augmentation materials ranging from autogenous, allogenic, xenogenic and synthetic materials. A knowledge of these materials is essential prior to undertaking augmentation procedures. Knowledge of bone biology and bone physiology is also important.

Department of Maxillofacial and Plastic Surgery, Uppsala University Hospital, Uppsala, Sweden

S. Ebenezer

It is obvious that a thorough medical history should be obtained before implant treatment and prior to augmentation procedures. Patients should be evaluated regarding their general health status, medical history, history of any medication, allergies, the use of tobacco and compliance to oral hygiene methods. Patients with conditions that affect bone healing would be poor candidates for augmentation procedures. Patients with a history of head and neck radiotherapy, uncontrolled diabetes, transplant patients undergoing prolonged immunotherapy, patients undergoing bisphosphonate therapy or medications that could induce osteonecrosis of the jaws, heavy smokers and patients with neuropsychiatric disorders are high-risk patients to undergo augmentation.

It is also obvious that prior to undertaking augmentation procedures, adequate radiographic assessment of the region should be performed. In most situations, Cone Beam Computed Tomography (CBCT) is the imaging of choice.

The use of tilted or angulated implants, narrow implants, zygomatic implants, short implants or the use of nonimplant-supported prosthesis can avoid the need for augmentations, and this should be discussed with the patient prior to undertaking augmentation surgery [3, 4].

#### **19.2 The Alveolar Bone-Resorption Pattern and the Need for Augmentation**

The alveolar bone is functionally and macroscopically unique. It is that functional area of the maxilla and mandible that is responsible for the anchorage of teeth. Both the mandible and the maxilla are irregular bones and are of mesenchymal origin. The maxilla consists for the most part of cancellous bone with a thin cortex layer, whereas the mandible has more cortical bone and is denser. As the alveolar process of the maxilla and mandible are basically functional components to support the teeth, after tooth loss, the alveolar bone starts to resorb. However, the pattern of bone resorption in the two bones is different. The maxillary alveolar bone

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_19) contains supplementary material, which is available to authorized users.

V. V. Kumar (\*) · A. Thor

Department of Oral Surgery and Stomatology, University of Bern, Bern, Switzerland

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 407

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_19

resorbs from the labial plate inwards and the mandibular alveolar bone from the lingual plate outwards. Therefore, in the cases of long-standing edentulousness, this resorption pattern results in a narrower maxilla and mandible. The bone height is also reduced in a vertical direction in areas of tooth loss, leading to a reduced alveolar bone height in the maxillary posterior area (beneath the sinuses) and a reduced distance from the crest to the mandibular canal in the posterior mandible. The sagittal relation is also affected due to jaw atrophy, leading to an often retrognathic maxilla in relation to the wider mandible. In short, both the width of the bone (also called the volume of bone) and the quality of bone (described by Lekholm & Zarb and Cawood & Howell), [5, 6] must be taken into consideration before implant placement. Additionally, due to ridge resorption, the vertical and sagittal bone relations between the upper and lower jawbones and the toothless space must be taken into consideration before implant placement and bone augmentation, when treatment is planned from a prosthodontic point of view. Figure 19.1 shows the changes in edentulous jaws and the classifcation of bone quality and bone quantity as described by Lekholm and Zarb, 1985.

Also, in patients with tooth loss secondary to other reasons of bone loss such as trauma, pathologies, etc.; bone should be replaced to reconstruct the lost tissue as well as to support placement of implants in the best prosthetically driven position.

#### **19.3 Bone Biology**

**Fig. 19.1** Classifcation of bone for implant placement by Lekholm and Zarb, 1985. Adapted from Lekholm and

Zarb, 1985 [6]

Depending on the macroscopic form and mechanical function, bone can be designated as cancellous bone (also called spongiosa or trabecular bone) and cortical bone (also called compact bone). Cortical bone is the dense outer aspect of bone that is responsible for the mechanical strength. The inner cancellous part of the bone that predominantly consists of bone marrow and provides nutrition to the bone [7].

Microscopically cortical bone consists of concentric circles of osteons (also known as Haversian systems) (Fig. 19.2). Each osteon consists of a central canal of nerves and blood vessels that is surrounded by layers of compact bone. Microscopically, cancellous bone architecture consists of bone organised into a three-dimensional lattice framework called trabeculae. The trabecular spaces are flled with blood vessels and marrow. Bone marrow is a specialised connective tissue that produces erythrocytes, leucocytes, platelets and osteoblasts. Depending on age and location, bone marrow additionally contains fat cells and other connective tissue elements [8].

Under higher magnifcation, bone can be further designated as woven or lamellar bone. Woven bone is immature bone that forms following injury to mature bone (such as fractures or tooth extraction) or during the foetal growth period. After an injury to mature bone that causes a break in its continuity such as tooth extraction, a haematoma results and following this woven bone is formed rapidly to fll the defect in the bone. This bone is mechanically weak and its collagen fbrils have a random orientation. Woven bone is then replaced by mature and mechanically strong lamellar bone that has collagen fbrils arranged parallelly and regularly into distinct layers.

Bones of the human body are in a constant state of renewal, the process known as bone remodelling. Bone remodelling is essential to regulate mineral balance in the bone and circulatory system, as well as to maintain bone strength. Regular day stress and strain causes microdamage in bone, which is repaired and replaced by new bone by the

©Association of Oral and Maxillofacial Surgeons of India

lacunae

©Association of Oral and Maxillofacial Surgeons of India

process of bone remodelling. Therefore, the process of bone remodelling helps the bone to adapt to changing mechanical and biologic needs during the lifetime of the individual. For the ease of description, bone remodelling can be divided as consisting of four continuous stages:

 bone resorption, reversal phase, mineralisation phase and resting phase (Fig. 19.3).

During the resorption phase, specialised cells called osteoblasts are activated, which eat away old bone. In the reversal phase, bone-forming cells known as osteoblasts begin to appear on the surface of the resorbed bone. In the bone-formation phase, the osteoblasts lay down osteoid, which is the unmineralised organic portion of bone and bone mineralisation occurs when calcium hydroxyapatite and other minerals are incorporated into the organic unmineralised osteoid, thereby providing mechanical strength. Bone remodelling occurs all throughout life and consists of a closely coupled phenomenon of bone apposition and resorption. Under normal healthy conditions in adults, bone resorption and apposition during remodelling are balanced in time, space and amount so that the bone mass of the body remains more or less constant.

#### **19.3.1 Composition of Bone**

Bone is a connective tissue that consists of bone cells (approximately 10%) in a connective tissue matrix (approximately 90%). Cells of the bone are the osteoblasts, the osteocytes and osteoclasts. The osteoblasts are large uninucleate cells that form bone. They work in groups and predominantly lay down the collagen matrix known as osteoid. Osteoblasts also produce proteins such as bone morphogenetic proteins that stimulate bone healing and mineralisation. About 10% of the osteoblasts become entrapped inside the calcifed bone matrix and are known as Osteocytes. Osteocytes reside in small bone cavities known as lacunae and are interconnected with each other and with osteoblasts and lining cells on the bone surface. Osteoclasts, on the other hand, are multinucleated cells that line the surface of the bone where resorption takes place.

These cells release powerful degrading enzymatic proteins that are responsible for the removal of bone minerals.

The extracellular bone matrix consists of about 35% organic and 65% inorganic materials. About 90% of the organic phase is collagen type I fbres, while the remaining 10% consists of various non-collagenous proteins. The bone matrix also contains growth factors such as the bone morphogenetic proteins important for bone healing. The inorganic phase of the bone matrix consists of low-crystallinity carbonated hydroxyapatite [9].

#### **19.4 Bone Grafts and Bone Substitutes**

Currently, there are a wide variety of biomaterials that can be used for bony augmentation [10].

Table 19.1 describes the classifcation of bone grafts [11] (Adapted from Katsuyama H., Jensen S.S. Treatment Options for Sinus Floor Elevation).

Most commonly, bone grafts and bone substitutes are classifed according to their source of origin in relation to the intended recipient. Autogenous or autologous bone grafts are obtained from the same individual. Allogeneic bone grafts or allografts are obtained from a genetically distinct individual of the same species. In contrast, xenogeneic bone grafts or xenografts are obtained from a different species than the intended recipient. Alloplastic bone substitutes are synthetically produced materials.

*Autogenous bone graft or autograft* refers to bone originating from the same patient, and it can be harvested from intra-oral or extra-oral sites. It is preferred to harvest the bone as close to the surgical defect as possible in order to avoid donor-site morbidities. However, of course this decision is dependent on the amount of bone required. For smaller augmentations and guided bone regeneration, bone is commonly harvested from the bone tissue neighbouring the defect site. In this case, donor-site access can be gained from the same incision that is used to access the recipient site. In cases where slightly larger amounts are needed, bone can be harvested from the anterior mandibular ramus or the mandibular symphysis. These are the most common intraoral bone donor sites. Although one may need an additional



Adapted from Katsuyama H and Jensen S.S: 2011 [11]

incision to harvest bone in intra-oral sites, these can be obtained in the same surgical area. When even larger amounts of bone are needed, harvesting from extra-oral sites is needed. The most commonly used donor sites are the iliac bone, the calvarium and the tibia. In most of these cases with the need of an extraoral donor-site harvest, the surgical time as well as hospital stay is often prolonged. A more detailed explanation of different donor sites is provided in the section on onlay bone grafting. In the case of very large bony reconstructions where the defect size is more than 6 centimetres, vascularised bone containing free faps are used, such as the free fbula fap [12, 13]. These procedures are commonly carried out for benign and malignant tumours, and are not described in this chapter, but described in detail in the relevant chapter of this textbook.

*Allogeneic bone graft* or allograft refers to bone originating from another human, either a living donor or following the death of an organ donor. Usually, the allogeneic bone is harvested from the iliac bone or tibia and can be fresh-frozen, freeze-dried or processed as demineralised freeze-dried bone.

*Xenogeneic bone substitute or xenograft* is bone-substitute material originating from another species. These could be sea algae, corals, equine (originating from horses), porcine (originating from pigs) or most commonly, bovine (originating from cows).

Bone-substitute materials can also be manufactured purely by synthetic means, produced in the laboratory. These are called *alloplastic graft materials* examples of these are hydroxyapatite, beta-tricalcium phosphate, calcium silicophosphate, bioglasses, polymers, titanium particles or a combination of these.

#### **Box 19.1**

*Block bone grafts/Particulate bone grafts:* Depending upon the shape and constitution of the bone graft, they can be described as block bone grafts or particulate bone grafts or a combination of these. Bone blocks are large pieces of autogenous bone. Autogenous bone that has been harvested by bone scrapers and chisels is in the form of small chips and is referred to as a particulate graft. Particulate grafts can also be made from block grafts by using special milling machines to break down the block (Fig. 19.4a, b).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 19.4** (**a**) an example of block bone graft (**b**) an example of a particulate bone graft

#### **19.4.1 Classifcation of Bone Grafts Based on the Mechanism of Action**

Bone grafts can also be described and classifed based on the mechanism of action and biological activity into *osteogenic, osteoinductive and osteoconductive*.

#### **Box 19.2**

*Osteogenic grafts* provide a source of new bone formation by the osteoblasts that are present in the graft material. At present, this can only be seen in the cases of autogenous bone grafts, where the donor bone is from the same subject and the transplantation procedure has preserved the viability and vitality of osteoblasts in them. Developments using stem cell harvesting may enable development of osteogenic bone grafts without the use of the subject's own bone tissue.

*Osteoinduction* is defned as the mechanism whereby a bone-substitute material induces bone formation by stimulating undifferentiated mesenchymal cells to turn into osteoblasts, which in turn produce new bone. Many proteins such as bone morphogenetic proteins are being investigated for their osteoinductive properties.

*Osteoconduction* is the mechanism whereby bone formation is enhanced by providing a scaffold for osteogenic cells that are present in the local environment of the host. Osteoconductive materials form a passive support for cells to migrate and colonise the scaffold and then produce new bone.

In spite of the large number of products available in the market, the gold standard in bone augmentation is autogenous bone. Depending on the indication for grafting and the amount of graft needed, autogenous bone can be used in a particulate form that is used either stand alone, or mixed with a bone-substitute material, used encased in titanium meshes or membranes, as a block graft, or as combination of any of these. Vascularised autogenous bone grafts such as the free fbula fap, the iliac crest and scapula free fap can be used not only as bone faps but also as composite tissue to reconstruct complete jaws.

Bone augmentation and healing of the graft occurs in the following stages [14]: The surgical intervention gives rise to a haematoma and an acute infammatory reaction, which is similar to the most cases of tissue trauma. This infammatory reaction invokes a migration of infammatory cells into the region, along with osteoblasts and osteoblast precursor cells. In a day's time, proliferation of blood vessels and the beginning of granulation tissue formation occur. This phase is followed by the resorption of the graft by osteoclast precursor cells, and in the case of autogenous bone, this releases bone morphogenetic proteins from the bone matrix, marking the start of the osteoinductive activity. At the same time, osteoblasts from the host bone start to migrate into the grafted region and begin to produce new bone, marking the phenomenon of osteoconduction. The graft is over time incorporated into the regional host bone by undergoing varying degrees of resorption and remodelling.

Although the procedure is largely similar regardless of the origin of the bone graft, the properties of osteoinduction and osteoconduction as well as biocompatibility can vary depending upon the particular bone-substitute material in use. Most bone-substitute materials are osteoconductive and vary in the resorption and bone turn-over rates. As a result, certain materials are shown to completely resorb within a period of a few months, whereas certain bone-substitute materials are present after many years.

*Autogenous bone* is the only type of graft that contributes to bone regeneration via all three mechanisms. A limited number of osteoblasts survive the procedure of grafting and these cells contribute towards osteogenesis; the graft itself provides a scaffold for osteoblasts from the host site to migrate into, facilitating osteoconduction; fnally, the growth factors included within the graft matrix and released during graft resorption facilitate osteoinduction. Autogenous bone also has a high rate of resorption.

*Allogeneic bone* grafts are classifed as mineralised and demineralised. Mineralised allografts—such as fresh frozen bone allograft and freeze-dried bone allograft—contribute to bone regeneration primarily through osteoconduction, but they may also possess some potential for osteoinduction. On the other hand, demineralised freeze-dried bone allograft is said to contribute to bone regeneration primarily through osteoinduction, and only secondarily by osteoconduction. However, it should be noted that variations in the processing of allogenic bone grafts from different tissue banks using different methodologies result in a large variation in the composition as well as osteoconductive potential of demineralised freeze-dried bone.

The choice of a commercially available bone-substitute material is most commonly based on the preference of the recipient patient (some patients would not like bone substitutes from an animal source or a cadaveric source), the available product information and documentation of clinical success, product availability, the ease of use and the preference of the clinician.

#### **19.5 Barrier Membranes**

Barrier membranes are an important component for the success of the GBR procedure. Ideally, the barrier membranes must be non-toxic, biocompatible, cell occlusive with a certain degree of permeability for diffusion of nutrients, permit bonding and ingrowth of connective tissue during healing, should be of suffcient rigidity to maintain the space created and not collapse into the defect, it should be easy to handle clinically and should be able to be trimmed to tailor the material as per the size of the defect [15].

Although traditionally many materials such as PTFE had been developed as membranes, currently most membranes being used are made up of collagen (type I, type III or a combination of these) [16]. These collagen membranes are derived from porcine or bovine sources [17]. Collagen membranes resorb as a result of enzymatic action of macrophages and polymorphonuclear leukocytes. Some manufacturers cross-link collagen membranes with glutaraldehyde to reduce the rate of membrane resorption, thereby prolonging the barrier function. However, crosslinking with glutaraldehyde can result in cytotoxic residues in the membrane following its manufacture. Resorbable membranes have a less likelihood to cause early membrane exposure, and that additionally due to the property of being resorbable, they do not need to be removed at a second surgical procedure.

Clinically, the main advantage of resorbable membranes is their decreased susceptibility to infective complication. If premature membrane exposure occurs, secondary soft tissue healing takes place within 4 weeks, and the bone-regenerative outcome remains favourable. Collagen membranes are also easier to handle clinically and adapt well to the surgical site once they are wet with blood or saline. Signifcantly, the membranes do not need to be removed via a second surgical procedure because they biodegrade. The main disadvantage is that non-cross-linked collagen membranes collapse easily because they do not have space-maintaining properties.

When a membrane with insuffcient stiffness and rigidity is used in larger defects, there is a high likelihood of membrane collapse. Collapse of the membrane would lead to a situation where there would be no space for guided bone regeneration. Hence, clinically this problem is solved by using a bone graft or a bone-substitute material that flls the bone defect and provides support to the membrane. Other methods to support the barrier membranes include the incorporation of bendable titanium frameworks into PTFE material, tenting screws to support the membrane and titanium mesh that can be shaped and adapted to the site. However, these procedures would require an additional surgical procedure to remove the hardware [18].

#### **19.5.1 Success Parameters of Autogenous Bone Graft Healing**

The success of bone augmentation is dependent on the ability of the augmented bone to support an implant fxture at the desired position. However, in biological terms the extent of graft incorporation, turnover, replacement, the volume stability and the time taken for healing are dependent on many factors such as surgical factors, patient-related factors and material-related factors. It has been shown in multiple systematic reviews and innumerable clinical studies that there is no one single superior bone-substitute material [14]. Bone augmentation, although having well-documented success rates, depends upon surgical as well as patient-related factors. Amongst the surgeon-related factors are the training of the surgeon, their surgical expertise, the adherence to protocol and treatment of the graft material as well as the recipient site, adequate fxation of the graft to prevent movement between the graft and recipient bone and so on.

Patient-related factors that contribute to healing include underlying systemic diseases such as immunodefciency, diabetes; local factors and habits such as oral hygiene and oral health, smoking and use of tobacco and defect-related factors such as the size of the defect and the morphology of the defect. It should be noted that smaller augmentations in a three-walled defect are more successful than large only vertical bone augmentation.

Regarding the infuence of the grafted material used, it has been shown that particulated autogenous bone has the advantage of relatively fast incorporation in comparison with autogenous bone blocks [19]. However, particulate bone lacks structural stability and is prone to undergo unpredictable and extensive resorption. In contrast, autogenous bone blocks provide structural stability leading to better dimensional stability. However, block grafting requires a longer healing period of at least 6 months with about 50% (half the initial augmented volume) resorption at the end of the healing period.

Regarding the infuence of bone-substitute materials, there exists a large variation in the physicochemical characteristics of the various bone substitutes available in the market, including their composition, particle size and form and surface properties. These differences can result in varying outcomes following augmentation.

Differences in the amount of new bone formation can be due to true differences in the osteoconductive potential of the biomaterial, but may also partly be explained by differences in resorption capacity amongst the various bone substitutes, which in turn determine the space available for new bone tissue formation within the defect site. For example, betatricalcium phosphate is replaced rather quickly, while sintered bovine bone is resistant to resorption and will be present in the augmented site for decades.

#### **19.6 Commonly Carried Out Augmentation Procedures**

Currently implantology has developed rapidly. Newer techniques and materials are constantly being introduced. The choice of procedure depends mainly upon the surgeon. Based upon the amount of bone augmentation required, the commonly carried out procedures are:

GBR (guided bone regeneration) Onlay bone grafting Sinus foor elevation These procedures are described in detail below.

#### **19.7 Guided Bone Regeneration**

Guided bone regeneration is a bone-augmentation technique that uses the principle of space maintenance within a bony defect with the use of a barrier membrane. The barrier membrane excludes rapidly proliferating epithelial cells and connective tissue fbroblasts, thus allowing the ingrowth of slower-growing bone cells and blood vessels into the blood clot within the defect.

The concept of guided bone regeneration was introduced and developed frst by Nyman and colleagues; Dahlin and colleagues in the early 1980s [20, 21]. Multiple animal studies showed that bone defects protected by a barrier membrane, which did not permit ingress of cells, had increased bone fll as compared to defects that were not protected by a barrier membrane. Although the technique was frst described for periodontal defects around natural teeth, later studies showed that GBR was also predictable in forming bone around implant defects.

Clinically, GBR is performed by raising a mucoperiosteal fap and exposing the bony defect. This defect is flled with a bone substitute and then covered with a barrier membrane. The bone defect with the bone substitute is flled with blood, which later clots and forms a haematoma. Over a period of time, the haematoma is ingressed by blood vessels and osteoprogenitor cells from the surrounding environment, which over a period of time forms bone tissue by resorbing the existing substitute and replacing it or growing into the substitute that acts as a scaffold. The barrier membrane prevents the ingress of fast proliferating fbroblasts and epithelial cells into the bone defect, thereby creating a space for bone to form and mature.

However, GBR does not produce similar successful outcomes in all morphology of defects [22]. The more the bone walls the defect contains, the better the bone fll following GBR. Bone walls provide an exposed surface of bonerecruiting cells. With more bone walls, an increased number of osteogenic cells are able to migrate along newly proliferating blood vessels into the haematoma in the defect. When two or three walls are present, the blood clot is less likely to be moved and better protected during the healing phase.

Guided bone regeneration can be applied for the correction of minor requirements of bone augmentation. They are documented to be successful in the following clinical situations:

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 19.5** (**a**, **b**) Shows a clinical case of GBR for a 2 walled defect


#### **19.7.1 Augmentation of 2 and 3 Walled Defects**

Guided bone regeneration can be successfully used in cases with crestal bone defects that are seen while placement of implants into extraction sites. If an implant can be placed with suffcient primary stability and results in a 2 or 3 walled defect, or if the defect is well contained in the bony envelope, GBR can be successfully performed at the time of implant placement. If these factors are not present, the augmentation must be performed prior to implant placement as a staged approach. In these cases, depending on the size and morphology of the defect, augmentation can be performed either by GBR, or by other augmentation methods described later in the chapter.

Figure 19.5a, b shows a case of GBR augmentation of 2 walled defect.

#### **19.7.2 For Augmenting Apical Fenestrations**

Often when implants are placed in the correct prosthetic position, with the correct angulation in order to provide screw retained restorations, the ideal angulation of placement would result in an apical fenestration, with the apical part of the implant threads being exposed. In these situations, the fenestration defects can be covered by using particulate bone/substitute material, covered with a membrane, as per the principles of GBR.

#### **19.7.3 GBR for Ridge Preservation**

During preoperative assessment and after extraction of a hopeless tooth that is planned to be restored with an implant, it is essential to inspect the shape of the resulting socket. In many situations, either due to trauma or chronic infection, the facial bone wall is missing. In these cases, it is important to augment the ridge/preserve the ridge at the time of tooth extraction. GBR can be well employed for this procedure known as ridge preservation/alveolar ridge preservation. In cases of acute infection in the sockets, ridge preservation can be carried out at a later stage after the infection has subsided.

#### **19.7.4 GBR in Combination with Other Larger Augmentation Procedures**

In the cases of localised prolonged ridge atrophy, GBR can be combined with other methods of augmentation such as with block grafts or ridge split techniques. In the cases of prolonged ridge atrophy affecting a complete segment of the jaws, the bone defects would often contain a single wall or two walls with a requirement for larger volumes of grafting. GBR alone will not provide a suffcient amount of bone augmentation. In these situations, it is advisable to augment using block grafting, and in addition use particulate bone graft around the blocks and protect the augmented particulate material with a membrane. Implant placement can then be carried out after a period of around 6 months.

#### **19.7.5 GBR for Contour Augmentation**

One successful method of placing implants is following 4–8 weeks of healing. In this situation, in contrast to immediate implant placement, soft tissue healing would have taken place, thereby permitting the clinician with better quality of soft tissues while placing implants. However, in this scenario, especially in the aesthetic zone, the resorption of the facial bone would produce crater-like bone defects. GBR can be done in these situations, to over correct the lost facial bone as well as provide bulk to the region of implant placement. This procedure is also called 'contour augmentation' [23]. By doing this procedure, the buccal bone wall is intentionally overbulked so as to provide long-term stable aesthetic results as shown by multiple studies [24].

#### **19.8 Onlay Bone Grafting**

Onlay bone grafting is a predictable procedure carried out for the correction of cases with severe ridge resorption, either horizontally or vertically [25]. Autogenous bone grafts are the most documented and commonly used donor bone, although recently other allogenic and xenogenic materials are being clinically investigated. For augmentation of severe ridge defects (less than 2 walls and require more than 3 mm of augmentation), augmentation utilising autogenous bone blocks results in increased success rates as compared to guided bone regeneration alone. However, irrespective of the augmentation technique, vertical-ridge augmentation is less predictable as compared to horizontal-ridge augmentation [26].

Donor sites for autogenous onlay bone augmentation may be intra-oral or extra-oral. Most common intra-oral donor sites are the mandibular symphysis and the ramus of the mandible. Most common extra-oral donor sites for harvesting non-vascularised bone grafts are the iliac crest, the calvarium and the tibial bone. Most common vascularised bone containing free fap donor sites are the free fbula fap, the DCIA-free fap and scapula-free fap.

Once the bone graft is harvested, they should be trimmed and shaped to ft into the recipient site defect, stabilisation with osteosynthesis screws followed by adequate soft tissue mobilisation and tension-free primary closure of the grafted site. It is advisable to over-augment the defect in order to compensate for the eventual resorption. A mixture of particulate bone, slow-resorbing xenografts either alone or in combination is used to fll up the area between a corticocancellous block and the recipient site. The augmented material may be protected with a barrier membrane prior to being enveloped by the soft-tissue closure.

#### V. V. Kumar et al.

#### **19.8.1 Harvesting Bone from the Donor Site**

#### **19.8.1.1 Mandibular Ramus as the Donor Site**

The outer cortical plate of the ascending ramus of the mandible is a popular choice for the harvest of intra-oral bone. This is probably because many oral and maxillofacial surgeons are well accustomed to the approach to the ramus during routine mandibular third molar surgeries or routine orthognathic surgeries. (Fig. 19.6a, b, c shows harvest of bone from the mandibular ramus).

The incision starts with a crevicular incision around the last standing molar teeth and continues along the ridge curving buccally upwards along the external oblique ridge. After elevation of the mucoperiosteal fap, and gaining adequate access to the anterior and lateral border of the ascending ramus of the mandible and the angle region, bone harvesting can begin. Usually, a block graft of approximately 30 mm × 15 mm can be harvested. The block thickness depends on the thickness of the lateral cortical bone plate of the ascending ramus and can vary from about 3 to 4 mm. The outline of the graft is usually made with two parallel anterior and posterior osteotomy cuts of about 3 mm in depth, on the lateral surface of the ramus of the mandible till the cortical bone is penetrated completely. Round bur points can also be made outlining the bone graft prior to making parallel cuts. Use of piezosurgery is advantageous in the cases of bone grafting. The two horizontal osteotomies are then joined by the sagittal bone cut superiorly. This cut corresponds to the thickness of the cortical bone. Once the sagittal bone cut is complete, the bone graft can be gently fractured and mobilised by the introduction of an osteotome or a periosteal elevator. Some surgeons prefer to make a cortical cut at the inferior end of the bone block prior to introducing the periosteal elevator to prevent unfavourable fractures of the block graft. After bone harvest, the surgical area is irrigated well and a haemostatic agent is applied if necessary and the wound is closed in layers. Some surgeons prefer to insert a glove drain that will be removed after 3 days.

#### **19.8.1.2 Chin (Anterior Mandible) as the Donor Site**

The chin is also a popular donor site, predominantly because of the ease of access to the donor site. However, block grafts from the chin have shown an increased risk towards complications, especially neurosensory and vascularity disturbances to the mandibular incisors. Bone grafts of 50 mm in length and about 8 mm of width can be harvested. The cortical portion of the anterior mandible is thicker (around 3–11 mm) and hence the chin would provide a thicker area of bone and would be a choice for thick bone grafts. It is also popular to harvest bone grafts from the chin using trephine

$$\frac{\partial}{\partial t}$$

**Fig. 19.6** Shows harvest of bone from the mandibular ramus. (Picture courtesy PD Dr.med.dent. Simone Janner, Department of Oral Surgery and Stomatology, University of Bern, Switzerland). (**a**) Incision for access to ascending ramus. (**b**) Outline of the osteotomy. (**c**) Graft fxed at recipient site. (**d**) Coverage with membrane following additional particulate augmentation. (**e**) Closure

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 19.7** (**a**, **b**) Shows harvest of bone from mandibular symphysis. (Picture courtesy PD Dr.med.dent. Simone Janner, Department of Oral Surgery and Stomatology, University of Bern, Switzerland). (**a**) Harvest of bone from symphysis. (**b**) Graft secured at recipient site

burs of varying diameters (7–12 mm), and using upto 4 trephine harvests. (Fig. 19.7a and b shows harvest of bone from mandibular symphysis).

The access to the chin is by a standard vestibular incision from one canine to another with approximately 15 mm away from the mucogingival margin. Once the mucosa is incised, the underlying mentalis muscle is seen, which is incised obliquely to reach the symphysis of the mandible. Full thickness fap is elevated and the donor site inspected. For harvesting larger grafts, it is advisable to expose both the mental foraminae. Once the donor site is exposed as per the requirement, the boundaries of bone harvesting are carefully noted. An intact area of 5 mm must be preserved inferior to the root ends of the anterior teeth and 5 mm above the lower border of the mandible. Bone graft can be outlined within these borders, either using piezo surgical device or round burs or fssure burs or most popularly, trephine burs. After the outline of the bone graft is made, osteotomy of the cortical portion is done and connected. An osteotome or a periosteal elevator is then gently introduced to tease out the graft.

After harvesting of the bone graft, haemostasis is achieved and the wound closed in layers. It is important to close the periosteal layer and approximate the mentalis muscle prior to mucosal closure. A compressive chin dressing is provided to apply pressure to the donor-site region.

#### **19.8.1.3 Iliac Crest as the Donor Site**

Iliac bone provides a large quantity of bone and is the preferred donor site for large bone augmentation as it is an excellent source for cortical and cancellous as well as corticocancellous bone. Both the anterior and posterior iliac crest can be used as a donor site. Anterior iliac crest grafts are associated with higher complication rates of sensory disturbances, gait problems and untoward ilium fracture. Posterior crest grafts are associated with lesser complications but increased post-operative pain. Additionally, posterior crest grafts require the patient to be repositioned and hence many surgeons prefer the anterior iliac crest. (Fig. 19.8a, b, c shows a case of harvest of bone from iliac crest).

The harvest of bone from the anterior iliac crest is generally performed with the patient under general anaesthesia. The patient is positioned supine and the side of the pelvis to be operated on is raised by placing surgical towels or sandbag towels underneath the hip. The skin over the crest is made taut by placing a fst above the iliac crest and only pushing the abdominal wall medially. The skin incision is made generally about 2 cm larger than the intended length of the bone harvest, running parallel to the iliac crest, so that after relaxation of the taut skin, it lies lateral to the iliac crest thereby avoiding mechanical irritation of the scar. After skin is incised, blunt dissection of the subcutaneous tissue is made until the periosteum of the iliac crest is seen. Bleeding should be controlled during dissection. The periosteum of the iliac crest is incised and the periosteal layer with the attached muscle is elevated and refected medially. The iliac fossa is dissected to the desired depth. Care should be taken to avoid injury to the lateral femoral cutaneous nerve. Bone can be harvested using an oscillating saw or a piezosurgical device as per the preference of the surgeon by splitting the outer cortex of the iliac crest and transverse bone cuts. The two transverse cuts are then joined by a cortical osteotomy at the inner table paralleling the crestal cut. An osteotome is used to gently fracture the bone graft. This results in a cortico cancellous bone graft. Additional cancellous bone

©Association of Oral and Maxillofacial Surgeons of India

can be taken with a large curette if needed. The wound is meticulously closed in layers and a pressure dressing is applied.

#### **19.8.1.4 Calvarium as a Donor Site**

Calvarium is a good source of cortical bone graft due to its high density and is opined by some surgeons as being the most resistant to resorption [27]. The location of the donor site is at the parietal bone lateral to the sagittal suture. The bone has distinct outer and inner table at this region separated by a diploic layer. A typical situation where calvarial bone grafts are harvested is in the cases of residual deformities following trauma, where a bicoronal fap and exposure of the parietal bone are already planned. (Fig. 19.9a, b, c shows a case of calvarial bone harvest used for bone augmentation of the anterior mandible).

The harvest is performed under general anaesthesia and the parietal bone exposed as part of the bicoronal fap. The outline of the bone graft is frst made with round burs and then joined with straight fssure burs. The outline of the graft is broadened to permit placement of a chisel that would fracture the outer cortical plate at the diploic space. Haemostasis is achieved and the wound is closed.

#### **19.8.2 Recipient Site Preparation and Completion of the Procedure**

The preparation of the recipient site is done by a crestal incision with adequate releasing incisions as required. The surface of the bone is cleared of soft tissue and the cortical bone plate of the recipient site is perforated with a small round bur to produce bleeding and gain access to the cancellous part of the recipient bone. The harvested bone is then placed onto the recipient site and fxed with osteosynthesis screws. Some surgeons prefer to use lag screws for additional compression. The spaces between the block graft and recipient bone can be flled with particulate bone, especially at the borders. A resorbable membrane may be used to cover the augmentation. Adequate soft tissue release must be performed prior to

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 19.9** (**a**, **b**, **c)** shows a case of calvarial bone harvest used for bone augmentation of the anterior mandible. (**a**) Shows the exposure of the donor site with the outline of bone to be harvested. (**ba**) Shows the

cancellous side of the harvested bone. (**bb**) Shows the cortical side of the harvested bone. (**c**) Shows the harvested bone further shaped and fxed at the recipient site

closure, so as to provide a tension-free watertight closure. Onlay grafts are usually left to heal for at least 6 months, after which implant placement can be carried out as another surgical procedure.

Another variation of onlay bone grafting is to use the cortical shell technique, where a thin cortical shell of bone is harvested and cancellous bone marrow placed in between the cortical shell and the recipient bone wall.

Other methods of bone augmentation include ridge split for lateral augmentation, alveolar distraction osteogenesis for vertical augmentation, interpositional bone grafting and free fap reconstruction of extremely resorbed ridges [28, 29]. These procedures will not be described in detail as they are not the most commonly carried out procedures.

#### **19.9 Sinus Floor Elevation**

Sinus foor elevation, also known as sinus augmentation or sinus lift is a bone-augmentation procedure to gain an increased bone volume to support in the maxillary sinus following sinus pneumatisation. The bone augmentation is done to provide an adequate quantity of bone that would permit dental rehabilitation with implants.

Maxillary sinus foor elevation can be performed by either as a transcrestal technique (also known as indirect sinus foor elevation) or a lateral window technique (also known as direct sinus foor elevation).

Irrespective of the individual techniques, the principle is to elevate the Schneiderian membrane and to create space for bone to fll up between the elevated Schneiderian membrane and residual maxillary bone. Although most clinician commonly use bone grafts to fll the space between the membrane and the foor, it has also been shown that bone fll occurs irrespective of using a bone substitute or leaving the elevated area to be occupied by a blood clot that eventually forms bone [30–32]. (Fig. 19.10a, b, c, d shows a clinical case of sinus foor elevation with blood clot and no additional biomaterial).

The maxillary sinus is a pyramidal-shaped cavity in the posterior region of each of the maxillary bones. The base of this pyramid is the lateral nasal wall and the tip of the pyramid is within the zygomatic buttress. The infraorbital foor, the posterior maxillary wall and the alveolar process form the walls of the pyramid. The maxillary sinus communicates **a**

**c**

**e**

**Fig. 19.10** (**a**, **b**, **c**, **d**, **e**) shows a clinical case of sinus foor elevation with blood clot and no additional biomaterial. (**a**) Preparation of lateral window and elevation of the sinus membrane. (**b**) Implant osteotomy taking care to protect the membrane. (**c**) Implant placed (note the space between the implant and membrane that will eventually fll with blood clot). (**d**) Closure of the lateral window. (**e**) Long-term follow-up radiograph showing successful implant placement and restoration

to the lateral nasal wall through the semilunar hiatus at the posterosuperior aspect below the medial nasal concha. At birth, the maxillary sinus is very small and underdeveloped. As the permanent teeth begin to erupt, the maxillary sinus increases in size and continues to grow along with age. The sinus foor (the alveolar bone) is concave in shape with the lowest dip corresponding to the maxillary molar region. However, after the loss of maxillary posterior teeth, the sinus usually dips into this region. Over a period of time due to the increasing pneumatisation of the sinus, the sinus may surround the roots of the maxillary posterior teeth. In the case of the loss of maxillary posterior teeth, the maxillary sinus expands thinning the foor of the alveolar process that may result in a thin shell of bone. In many situations, this expansion of the maxillary sinus leaves an inadequate amount of bone to support successful implant placement. In these situations, maxillary sinus foor elevation is the procedure of choice to augment bone. However, it is also important to bear in mind that alveolar bone resorption may give rise to vertical and horizontal defciencies in the posterior maxillary sinus. In prolonged cases, this might give rise to a situation where along with sinus foor elevation, it would also be necessary to augment bone both horizontally and vertically by onlay bone augmentation.

The morphology of the maxillary sinus foor can vary. Maxillary sinus foors are often irregular corresponding to the elevations and depressions of the teeth roots. The foor of the sinus also may be divided by septae. Some maxillary foors are broad and fat whereas others may be irregular and narrow. The lateral wall of the maxillary sinus can also vary in thickness, from being paper thin to being about 3 mm in thickness. The thicker the lateral wall, the more diffcult would be the lateral sinus foor-augmentation procedure.

The blood supply of the maxillary sinus arises from the branches of the maxillary artery namely: the posterosuperior alveolar artery and the greater palatine artery as well as the infraorbital artery. Care must be taken to look out for the posterosuperior alveolar artery that may be encountered while preparation of the lateral sinus foor augmentation, although it is unlikely to cause excessive bleeding.

As required for all surgical procedures, a thorough preoperative assessment must be carried out prior to sinus foor elevation. Acute sinusitis, oro-antral communications, chronic periodontitis and poor oral hygiene pose a high risk for sinus foor elevation. Moderate risk factors include smoking, chronic sinusitis and extremely poor bone density, amongst others.

#### **19.9.1 Classifcation and Treatment Options for the Posterior Edentulous Maxilla**

According to the International Team for Implantology, the edentulous posterior maxilla can be classifed into 4 types [11]:


Misch 1987 [33] classifed the edentulous posterior maxilla based on the amount of subantral bone available into:

SA1: more than 12 mm of the subantral bone height. SA2: 0–2 mm less than the ideal bone height (10–12 mm). SA3: 5–10 mm of the subantral bone height. SA4: less than 5 mm subantral bone height.

#### **19.9.2 Decision-Making: Lateral Versus Transcrestal Technique**

Transcrestal technique avoids the use of a large surgical fap and an osteotomy for a lateral window and hence is much reduced in invasiveness and decreased post-operative morbidity to the patient. However, the transcrestal technique can predictively increase bone height to about 4–5 mm and, therefore, cannot be used for severely atrophic cases. Additionally, in situations where the sinus foor is not uniform (or at oblique angles), there is an increased tendency to perforate the sinus mucosa. In such cases, it is preferable to perform lateral sinus foor elevation. It must be remembered that the transcrestal technique is in essence a blind procedure and it is not possible to inspect the sinus mucosa for perforations or pathologies using this technique, hence in the cases of intra-operative perforation, a lateral sinus foor elevation procedure must be performed. Hence, it is wise to always obtain a consent for the lateral technique prior to undertaking the transcrestal procedure.

#### **19.9.3 Decision-Making: Simultaneous Versus Staged Approach**

The prerequisite of simultaneous implant placement is the possibility to obtain suffcient primary implant stability [33, 34]. In cases where primary implant stability cannot be obtained, implants should be placed at a second surgical procedure 2–6 months following sinus foor elevation. Decreased residual bone volume and poor bone density are factors that predispose towards poor primary implant stability. Traditionally, less than 5 mm was considered as the minimum amount of sub-antral bone height required for simultaneous implant placement. This has. However. been challenged and many recent studies have shown suffcient primary stability in cases with lesser sub-antral bone height. Implant stability has been achieved in these cases by using a tapered implant design, implants with engaging threads, by using the underdimensional drilling protocol and by using bone-condensing drills. Conventionally, it is understood that while undertaking a transcrestal procedure, implants would be placed simultaneously.

*Armamentarium* for sinus foor elevation consists in addition to the regular minor surgical kit and the implant kit, hand and rotary instruments that are specifcally designed for sinus foor elevation. Many companies have introduced kits specifcally for this procedure. Some surgeons prefer the use of piezosurgery for access to the lateral window. Additionally, implant companies have also introduced specifc burs and elevation kits that reportedly make sinus foor elevation easier to perform. It is ultimately the preference of the surgeon in choosing the armamentarium.

#### **19.9.4 Transcrestal Surgical Technique**

After local anaesthesia, a crestal incision is made and the implant osteotomy is performed according to the instructions of the respective implant manufacturer. The osteotomy is made 2 mm short of the sinus floor. A periapical radiograph can be taken to confirm this. After the depth has been defined, remainder of the implant preparation is done as per the respective manufacturers protocol. Following preparation of the implant bed of appropriate dimension (it is recommended to use an implant of at least 4.0 mm diameter till further evidence suggests otherwise), an osteotome is introduced into the implant bed and with the help of a mallet, gentle tapping is performed till the sinus floor is fractured. Care should be taken that the osteotome does not perforate the sinus mucosa and enter the sinus cavity. Once the sinus floor has been fractured, a part of the membrane can be visualised to be intact. A careful Valsalva procedure can also be performed to test the patency of the sinus floor. An appropriate graft material is introduced through the implant preparation onto the sinus mucosa. Incremental introduction of the graft material is done, which will push the sinus membrane upwards creating a space between the sub-antral bone and the sinus mucosa. After introducing the appropriate amount of graft material, an implant is inserted to the desired three-dimensional position. Following implant installation, the crestal incision is closed with either a transmucosal or submerged healing protocol. Implant loading is done as per the instructions of the manufacturer, generally within 3 month time. (Fig. 19.11a, b, c, d shows a digrammatic representation of transcrestal sinus floor elevation).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 19.11** (**a**, **b**, **c**, **d**) shows a diagrammatic representation of transcrestal sinus foor elevation. (**a**) Implant osteotomy made 2 mm short of the sinus foor. (**b**) Osteotome introduced through the implant oste-

otomy to fracture the sinus foor. (**c**) Biomaterial introduced to elevate the sinus membrane. (**d**) Implant placement completed

A periapical radiograph must be taken at the end of the procedure to confirm no breach of the sinus floor. A wellcircumscribed dome-shaped elevation around the apex of the implant confirms no breach of the sinus membrane. In contrast, if the bone graft is seen around the sinus floor and poorly localised, it denotes a perforation of the sinus floor membrane and in this case, a lateral window approach should be immediately done to clean the sinus cavity.

#### **19.9.5 Lateral Window Technique**

The lateral window technique can be done alongside lateral and vertical augmentation of the ridge, and with or without simultaneous implant placement. After adequate local anaesthesia, a crestal incision is made with releasing incisions well away from the planned window. A mucoperiosteal fap is elevated and the lateral wall of the maxillary sinus is exposed. A bony window is made according to the local bone anatomy. If vertical septae are present, two bony windows are made on either side of the bony septae. The bony window should be large enough to introduce the graft materials, as well as big enough to permit exploration of the foor, the anteroposterior aspect of the foor to the medial aspect of the maxillary sinus. When the lateral window is made, care should be taken to avoid perforation of the sinus membrane. The lateral window can either be removed from the underlying sinus mucosa or be attached to the to it and pushed inwards. The sinus foor is then slowly teased and refected away from the foor of the maxillary sinus and elevated using special instruments that resemble a curette to create space for the graft material. It is important to elevate the membrane medially and anteriorly in the areas where augmentation is planned.

(Fig. 19.12a, b, c, d shows diagrammatic representation of the procedure for sinus foor elevation using a lateral window).

If simultaneous implant placement is planned, implant osteotomies should be carried out with the elevated mucosa well protected with an instrument in such a way that the implant drills do not come in contact with the sinus mucosa. Bone graft material is now introduced into the space created by elevation of the membrane. After adequate flling of the space with augmentation material, implants can be placed if planned. The lateral window bone wall (if preserved) can be replaced, or the window can be covered with a barrier membrane. The mucoperiosteal fap is then closed and tensionfree suturing should be placed.

Although, bone graft materials and membranes are commonly used it is not mandatory for the success of sinus foor elevation. Some suggest, elevation of the sinus mucosa and placement of the implant that tents the membrane up, the blood clot that is formed into the space eventually forms bone to surround the implant.

#### **19.9.6 Complications Following Sinus Floor Elevation**

Sinus perforation is the most common complication following sinus foor elevation. Other complications include (but not limited to) poor primary implant stability, implant migration into the sinus, graft migration into the sinus and intraoperative and post-operative bleeding, wound dehiscence and infection.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 19.12** (**a**, **b**, **c**, **d** shows diagrammatic representation of the procedure for sinus foor elevation using a lateral window). (**a**) Mucoperiosteal fap elevated to access the lateral wall of the maxillary sinus. (**b**) Lateral wall bony window made and in-fractured. (**c**) Implant osteotomy done. (**d**) Placement of biomaterial and implant

Alternatives to sinus foor elevation: The use of short implants [35], angled or tilted implants [3], zygomatic or pterygoid implants [36] are treatment alternatives that may avoid the need for maxillary sinus foor elevation.

#### **19.10 Suggested Reading**

ITI Treatment guides Volume 5: Sinus foor elevation

ITI Treatment guide Volume 7

ITI Treatment guide series Volume 1–10

ITI Online Academy

Contemporary implant dentistry: Carl Misch

#### **References**


bilitation – implant and peri-implant related outcomes of a randomized clinical trial. J Craniomaxillofac Surg. 2016;44(11):1849–58.


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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**Part VIII**

**Odontogenic Infections**

## **Odontogenic Infections: General Principles**

**20**

Anand Shukla and Divya Mehrotra

#### **20.1 Introduction**

Relationships like symbiosis, commensalism, ectoparasitism, and endoparasitism exist between various species in the biological world. An infection is a classic example of either ectoparasitism or endoparasitism. All infections occurring in the human body are usually of microbial origin and odontogenic infections are no exception.

This relationship is based on discordance in the delicate balance between the host defense mechanism and pathogenicity or the virulence of the infecting microbes depending upon their potentially harmful biomolecules viz. exotoxin, endotoxin, enzymes, and others that disrupt the host defense. Essentially, the environment also seems to play an important role in the overall pathogenic behavior of the microorganism. This interrelationship can be expressed by a simple triangle.

Host (Immunity) Environment (pH/Nutrition/O2 Tension)

In short, when a low host resistance, pathogen-friendly environment, and a pathogen of high virulence are seen in states of physical being, we refer to as Infections

Department of Oral and Maxillofacial Surgery, King George's Medical University, Lucknow, India

### **20.2 Host Defense Mechanisms**

As a generalization, host defense mechanisms may be studied as

	- 1. Oral Mucosa:

The oral mucosa forms the frst line of defense against the pathogens with an epithelialization rate of 4–5 days wherein the entire oral mucous membrane is replaced by newer more equipped cells take its place. The cells that are infected or otherwise worn out are replaced. As both the skin and oral mucosa are keratinized structures, water and along with it the microbes cannot naturally percolate into the deeper tissues. The oral mucosa is water resistant and relatively dry and does not form a congenial niche for microbial adherence and growth.

2. Natural spillways:

Human dentition has evolved to chew the food we eat. The surface anatomy of the occlusal surfaces is such that with a fbrous diet, the food automatically spills off the occlusal table into the labio-lingual vestibule. The interdental contacts are also evolved and provide natural spillways for masticated food.

3. Dental Histology:

The microscopic structures of our dentition reveal the hardest substance of the human body (the dental enamel) to cap its relatively softer structures (dentin and pulp). Thus, even if microbes are able to hold onto the enamel layer, the sheer density and mineralization of this layer are suffcient enough to handle most of the microbial attacks.

A. Shukla ∙ D. Mehrotra (\*)

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 429

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_20

4. Saliva:

By virtue of evolution, the human race has been privileged with 3 pairs of major salivary glands and numerous minor salivary glands. Their secretions, on the one hand, keep the oral environment moist to avoid inadvertent trauma and, on the other hand, help transform the chewed food into a bolus to be swallowed. Salivary secretion continues throughout the awake state, so even if one is not eating, the salivary secretions fush out the food debris deposited on the hard and soft surfaces of the mouth, in conjunction with the movements of the muscular elements of oral region such as lips, cheek, tongue, etc. Other physiological properties of the human saliva such as pH (6.5–8.5) and the presence of immunoglobulins (IgG and IgA) makes saliva a biological bacteriostatic fuid.

5. Oral sub mucosal immune system (OSMIS):

A large number of immunocompetent cells, such as the mononuclear leukocytes, T cells, and B cells, are present between the oral mucous membrane and are responsible for the production of antibodies as well as offering a direct cellular immune response to the host and oral environment. The cell concentrations of IgG, IgA, and IgM may remarkably reach 85, 72, and 75%, respectively, with respect to plasma concentration, in the gingival sulcular fuid. However, generally only IgA levels are high in the oral mucosa, while the concentrations of IgG may rise dramatically during infectious states. Also, the true ponderance of mast cells in the submucosal layer and the presence of IgE explain the immediate hypersensitivity (type I) reaction. The role of these immunoglobulins is to neutralize the microbial toxins and maintain hemostasis in the oral environment.

6. Dentinal reparative mechanisms:

If the bacterial attack breaks the enamel barrier, the toxins reach the dentinal tubules and through them irritate the pulp. This may or may not be symptomatic but pulpal reaction is evident with the formation of reparative dentin to seal off the breach as part of the defense mechanism. When this occurs, we know it as arrested caries and the dentin so formed is the affected dentin. If due measures are not taken at this stage, an advanced carious lesion may result.

7. Waldayer's Ring:

The OSMIS, lingual tonsil, palatine tonsil, all other lymphoid structures in the naso-oropharyngeal region together make a ring-like primary defense mechanism against microbes in the oro-digestive tract and are constitutionally known as the Waldayer's ring.

	- 1. Cellular.
	- 2. Humoral.

Both these immune systems may be either innate (natural) or acquired (adaptive). Majority of pathogens are dealt with by the innate component of the host systemic immunity. However, when the innate response is overwhelmed, the adaptive or active immunity comes into play.

Components of Innate Immunity:


#### Components of Acquired Immunity:

	- Helper.
	- Cytotoxic.
	- Regulatory.

Innate immunity is basically a receptor-pattern recognition mechanism, where about 100 intracellular and extracellular receptors (e.g., toll-like receptors, NOD-like receptors, KIG like receptors, etc.) recognize over 1000 different cell injury-related patterns generated from bacterial, viral, or fungal infictions [1]. These receptors generate a response mediated by cytokines and antiviral interferon and stimulate the most proactive immune response.

Acquired immunity is of two types, viz. humoral immunity, mediated by soluble proteins known as antibodies (produced by B lymphocytes) and cell-mediated immunity effected by T lymphocytes (T cells). While antibodies provide protection against extracellular pathogens in blood, mucosa, and tissues, T lymphocytes work to defend against intracellular microbes to kill ingested microbes by production of soluble proteins mediators, the cytokines (produced by helper T cells).

#### **20.3 The Infectious Microbes**

The concept of an infectious agent was established by Robert Koch. Koch's postulates became the standard for defning infectious agents, but they do not apply to uncultivable organisms (e.g. M. leprae) or members of normal humoral fora (e.g. *E. coli*).

Koch's postulates:


Odontogenic infections arise within or around the dentition, initiating from simple dental caries, periodontal diseases, and pulpitis, and may spread way beyond their loco-regional origin, invading deeper structures of the face, oral cavity, head and neck, and even mediastinum or the vertebral column.

These infections are principally bacterial in nature Tables 20.1 and 20.2. These bacteria are a part of normal oral fora found in the dental plaque, mucosal surfaces, and the gingival sulcus. These primarily are aerobic gram positive cocci, anaerobic gram positive cocci, and gram negative rods [3].





#### **20.4 Pathways of Odontogenic Infection**

Odontogenic infections have two major origins (Fig. 20.1).


Once the periodontal or periapical tissues get inoculated with bacteria, the infection may spread equally in all directions but mostly follows the path of least resistance. It travels through the cancellous bone to reach the cortical plate. If the cortical plate is thin, infection easily perforates it to enter the surrounding soft tissue. Periapical enzymes that help the bacteria in doing so include collagenase, hyaluronidase, and streptokinase, which dissolve through the organic matrix of the bone, while the acids produced by the bacteria eliminate the mineral content.

At this stage, if an intervention such as an endodontic or periodontal procedure or dental extraction is done, the further spread may be arrested or even abolished with judicious antibiotics. Antimicrobials alone may not cure the condition as the focus of infection from necrotic pulp or periapical tissues still remains and may cause recurrence of the infection, if the therapy is stopped [5].

When left untreated, the infection continues to spread depending principally on the thickness of bone and the type of muscle attachment. For example, if maxillary anterior tooth gets involved in the periapical region and the inclination of the root is such that the apex is closer to the labial cortical plate, the soft tissue reaction would present as swelling on the labial side (Fig. 20.3a) and if the apex is closer to the palatal cortical plate, swelling would be palatal. (Fig. 20.3b). Similarly, in case of carious involvement of maxillary frst molar: if the apices of the buccal roots lie above the attachment of the buccinator, swelling is likely to occur facially (Fig. 20.4a) and if apices are below, a vestibular swelling is more likely to occur (Figs. 20.4b and 20.5).

Apart from these factors, the angulation of root apex is also important. For example, in periapical abscess with respect to maxillary lateral incisor, swelling is likely to occur on the hard palate rather than labial vestibule as its root apex is slightly palato-distally curved. (Fig. 20.6).

Muscle attachment is another infuencing factor. Supposing a mandibular second molar gets apically infected and the apices lie above the external oblique ridge, infection following the path of least resistance and assisted with gravity, may manifest as swelling in a more anterior region of the jaw, buccally than the relative position of the frst mandibular molar. Similarly, in the mandibular posterior region, the lingual cortex is closer to the root apices and relatively thinner **Fig. 20.1** Natural progression of odontogenic infection

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 20.2** (**a**, **b**) shows a lower left second molar with a periapical radiolucency. On extraction, the periapical granuloma can be seen attached to the root. If this tooth was not extracted, the infection would have progressed in any of the pathways as shown in Fig. 20.1

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 20.4** (**a**, **b**) Effect of buccinator muscle attachment on the site of appearance of swelling in case of maxillary molars. In (**a**) the infection has localised to the vestibule while in (**b**) the infection has spread to the

buccal space, as the root apex is situated above the attachment of the buccinator muscle

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 20.5** Shows the clinical picture of a vestibular abscess arising from an infected upper right frst molar

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 20.6** Palatal abscess arising from upper incisors

as compared to the buccal cortical plate. If this gets perforated above the mylohyoid line, a sublingual swelling occurs and if below it, a submandibular swelling occurs.

The commonest manifestation of odontogenic infections is either a palatal or a vestibular abscess. When untreated, it may lead to an intraoral or extraoral drainage, in due course establishing a sinus tract. The treatment involves removing the cause (endodontically or via exodontia) and management of the sinus tract. In certain cases, the sinus tract resolves by itself, following the treatment of the offending cause (Fig. 20.7).

### **20.5 Pathways of Spread of Periapical Infections**

An odontogenic infection follows the path of least resistance. A periapical infection may perforate the nearest or the weakest cortex and travel along the soft tissue, initially as cellulitis and eventually resulting in abscess formation. This abscess may drain spontaneously, extraorally or intraorally and may involve one or more anatomically potential spaces. When this happens, it is known as a space infection.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 20.7** (**a**, **b**) Shows the periapical lesion in lower left frst molar in a 14-year-old patient causing extraoral sinus at the left lower border mandible region

Following are frequently affected anatomic spaces, (Fig. 20.8):

	- Subcutaneous. Vestibular. Buccal.
	- Temporal.
	- Medullary space of mandibular body. Submandibular. Sublingual.
	- Submental.
	- Masticator.
		- *Submasseteric*.
		- *Pterygomandibular*. *Superfcial temporal*.
		- *Deep temporal*.

Danger (Alar space). Prevertebral.

Various spaces involved in an infection differ in their relative severity depending upon the proximity of the vital anatomic structures in their vicinity. This may be seen as follows.

### **20.6 Various Space Infections and Their Relative Severity**

MILD—Vital structures and airway may be mildly threatened


#### MODERATE—Airway may be compromised


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 20.8** Pathways of spread of periapical infection. (1) Vestibular space. (2) Palatal abscess. (3) Maxillary sinus/odontogenic sinusitis. (4) Buccal space. (5) Submandibular space. (6) Sublingual space


HIGH—Vital structures or airway under direct threat


A. Shukla and D. Mehrotra


#### **20.7 Basic Therapeutic Principles**


Once the chief complaint is noted, history of present illness is determined with an estimation of how long back the patient was absolutely symptom free. Usually, infections have a short history of onset as compared to tumors in their acute state [6].

Next thing to be noted is any change in the patients' state of physical well-being since the symptoms frst appeared, i.e. if they have been the same, improved, or worsened with time. Since the response to an infection is essentially an infammatory one, classic sign of infammation are always looked for (tumor, rubor, dolor, color, and loss of function). Principal presenting feature is pain, so the nature of pain, site, and diurnal variation should be noted. A sharp, piercing, and lancinating type of pain is generated by Aδ nerve fbers that usually awake the patient at night (in accordance with the hydrodynamic theory of pulpal pain by Brannstrom [7]); however, a dull, aching, and gnawing kind of pain arises due to stimulation of slowly fring "c" type nerve fbers.

Swelling, redness, and rise of temperature should be inquired for and inspected even during history taking if these are apparent. Loss of function may manifest in the form of dyspnea, dysphagia, diffculty in chewing, or trismus [8]. A feeling of general malaise usually indicates a physical or physiological response against moderate to severe infection [9].

At this point, an enquiry into any previous treatments by another dentist, specialist, and/or self-treatment should be made and recorded. After carefully listening to the chief complaints and history of present illness, a comprehensive medical history should be recorded. The most effcient means of doing so is either by personal structured interview or by means of a questionnaire along with a discussion with the patient for any positive fndings.

History taking is followed by a physical examination that begins with the recording of patients' vitals as temperature, pulse rate, respiratory rate, and blood pressure. Patients with infections usually have elevated body temperature, and increased pulse and respiratory rates [10]. If the pain is signifcant, patient's blood pressure may be elevated. However, hypotension is seen in septicemic states. Since odontogenic infections are infammatory states, a partial or complete upper airway compromise may occur owing to an extension of the current infection to the deep facial spaces of the neck [11]. The patients may present with fatigue, fever, and malaise or so-called toxic appearance (Table 20.3) [12].

Palpation of swellings should be done to know the tenderness and consistency of the swelling. Consistency of a swelling may vary from normal, frm, feshy (dough like) to indurated (consistency of a taught muscle/wooden like/ brawny hard), or fuctuant (feel of a fuid-flled balloon). Fluctuation almost always indicates presence of pus in the center.

Intraoral examination gives a fair amount of idea as to the cause of the infection, i.e. the offending tooth. A careful look may reveal a grossly carious tooth/teeth, periodontal diseases, and/or a fractured tooth.

Investigative phase begins with a radiograph; intraoral periapical (IOPA) or orthopantomogram (OPG) depending on the symptomatology and clinical examination. CT scan may be required in severe cases to assess the pathway of the spread of infection [13].

If any surgical intervention is required, a routine blood assessment is always helpful in deciding the type of procedure to be followed.

A decision has to be made as to the stage of the infection, i.e. inoculation, cellulitis, or abscess stage. Usual attributes are as follows.

2. *Assessment of Immune response:* General medical history is the guide to detect any interfering systemic conditions that may compromise the host defense mechanism and may worsen patient's condition rapidly. Conditions of compromised host defense mechanism are as under:

#### **Table 20.3** Stages of infection



comprehensively where adequate support from the allied speciality is available.


Above discussion reinforces that while assessing a patient, a through medical history as well as a history of habits provides vital clues for the action to be adopted for his/her management.

	- (a) Failed earlier management.
	- (b) Medically compromised patients.
	- (c) Toxic appearance patients.
	- (d) Febrile patient: temperature greater than 101 °F.
	- (e) Signs of dehydration.
	- (f) Dyspnea.
	- (g) Diffculty swallowing (dysphagia).
	- (h) Moderate to severe trismus (with mouth-opening between 10 and 20 mm).
	- (i) Need for general anesthesia.
	- (j) Airway compromise.
	- (k) Signs of ascending or descending facial infections (cavernous sinus thrombosis/deep neck infections/ mediastinitis).

**Table 20.4** Indications for antimicrobial therapy


#### **20.8 Antimicrobial Therapy**

Once the culture and sensitivity reports are available, specifc antimicrobial therapy may be installed but meanwhile empirical antibiotics should be started immediately [16]. The choice of antibiotic should be carefully thought off to prevent unnecessary disturbance of the essential microfora of the gut and development of cross resistance (Also refer Chap. 10 of this book).

Cases of moderate to severe infection generally need postoperative antibiotics, where the host defense cannot be solely relied upon to fght the residual infection. Since the antibiotic sensitivity of usual causative organisms of odontogenic infections is fairly well known and consistent, an empirical therapy may include clindamycin, metronidazole, and penicillin. Metronidazole being narrow spectrum covers only obligate anaerobic population and the rest may be covered by other drugs dealing with facultative microbes.

Odontogenic infections are complex entities, both, on the basis of the plethora of fora associated and mechanism of their spread to the adjacent as well as distant anatomic Following principles should be additionally borne in mind before prescribing antibiotics [17]:


sites. Fortunately, culture and sensitivity behaviors of the causative microbes are fairly consistent and well understood. As such timely management should alleviate most of the dangerous outcomes but still these infections remain one of the leading cause of maxillofacial morbidity and at times mortality.

#### **20.9 Conclusion**

Odontogenic infection can be severe enough and become life threatening, hence should be dealt with very carefully. Proper evaluation of the signs and symptoms guide the clinician to make the diagnosis. Radiographic assessment may suggest the involvement of one or more teeth. Surgical intervention includes drainage of abscess, and pus be sent for culture and sensitivity to help choose the right antibiotic regime.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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## **Fascial Space Infections**

Rajasekhar Gaddipati

#### **21.1 Introduction**

There is considerable amount of change in the behavior of infections for the past one decade. The severity of infection is far greater than before which may be due to increased comorbid conditions, demanding swift action and aggressive treatment.

Fascial spaces do not exist in a normal healthy individual. These are latent spaces created by distention of tissues secondary to infection from the dental pulp, periodontal tissues and bone, where the infection perforates the cortical plate and discharge into the surrounding spaces.

The infections range from simple superfcial periapical abscess to deep infections in the neck region; some resolving with little consequences and some lead to life-threatening conditions.

Shapiro states that "The fascial planes are potential areas between layers of fascia. These areas are normally flled with loose connective tissue, which readily breakdown when invaded by infection". The infection started in any area is automatically limited by tough fascial layers. If the infection becomes massive, it breaks through a nearby fascial barrier into the next fascial space [1].

### **21.2 Defnition of Fascial Space**

The fascial spaces in the Head and Neck are the potential spaces between the various fascia normally flled with loose connective tissue and bounded by the anatomical barriers usually of bone, muscle, or fascial layers [2].

Facial planes offer anatomic highways for infection to spread superfcially to deep planes. Antibiotic availability in fascial spaces is limited due to poor vascularity.

R. Gaddipati (\*)

### **21.3 Spread of Infection**

The spread of the infections could be either through tissues, blood, or lymphatics leading to fatal consequences like Airway obstruction, Meningitis, and Septicemia; however, various factors infuence the spread of infection.

They are as follows:


In the Oral and Maxillofacial region, fascial spaces are almost always of relevance due to the spread of odontogenic infections. As such, the spaces can be classifed according to their relation to the upper and lower teeth, and whether infection may directly spread into the space called primary space, or must spread via a primary space to the secondary space [3].

#### **21.4 Classifcation of Spaces**

#### **21.4.1 Primary Spaces and Secondary Spaces**

Failure to adequately treat a primary space infection or a compromised host results in secondary space involvement (Table 21.1).

#### **21.4.1.1 Cervical Spaces**

Since hyoid bone is the most important anatomic structure in the neck that limits the spread of infection, the spaces can be classifed according to their relation to the hyoid bone:

**21**

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 441

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_21

Mamata Dental College, Khammam, Telangana, India

**Table 21.1** Classifcation of spaces in odontogenic infections based on mode of involvement



#### **Table 21.2** Severity score for spaces [4]



#### **21.4.1.2 Severity Score Anatomic Space** [4]

The severity score for a given patient is the sum of the severity scores for all of the spaces involved by cellulitis or abscess, based on clinical and radiological examination (Table 21.2).

The fascial spaces are divided into:


The infections arising from the maxillary anterior teeth spread to Canine space, while the infection from molars spread to Buccal space, Infratemporal space, or cause palatal abscess. Likewise, the infection from the mandibular anterior teeth spread to Submental space or cause gingival abscess. Infection from mandibular molars spread to the Sublingual space or the Submandibular space. While the infection from **Table 21.3** Characteristic features of cellulitis and abscess


mandibular third molars spread to Submasseteric space, Pterygomandibular space and Lateral Pharyngeal space.

However, it is not a "rule of thumb" for the involvement of a particular space with a specifc tooth infection.

#### **21.5 General Priciples of Management of Infection**


Pyogenic infections are primarily managed by surgical intervention comprising decompression or drainage. It is better to proceed with decompression at the earliest, without waiting for the localization of the infection (abcess formation), thereby preventing the spread of infection in tissue planes and mounting of pressure under the skin (Table 21.3).

Early decompression has the following benefts:


#### **21.6 Hilton's Method of Abscess Drainage**  (Figs. 21.1a and 21.1b)

This is a method of abscess drainage which ensures that no blood vessel or nerve in the vicinity of the incision is damaged.

**Fig. 21.1a** Hilton's method of transoral incision and drainage. (a) Abscess

incision given with blade. (c) sinus forceps is entered into the cavity and opened. (d) Drain entered into the cavity. (e) Drain secured with suture


**a**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 21.1b** Hilton's method of incision and drainage (extra oral site). (a) Incision given at the dependent site of the abscess. (b) Sinus forceps entered into the abscess cavity. (c) Sinus forceps opened in the cavity and removed. (d) Drain entered into the cavity and secured with suture

*Removal of the source of the infection is mandatory apart from drainage.*

#### **21.7 Medical Management**

Supportive management is mandatory in the form of antibiotics, anti-infammatory, and electrolytes. The reader is also advised to refer the chapter on general principles of management of facial infections (Chap. 20).

#### **21.7.1 Antibiotic Therapy**

Antibiotics are advised depending upon the patient's systemic condition; initially, after pus collection, empirical antibiotic is given; later, after the culture and sensitivity is performed, -specifc antibiotics are advised.

Route of administration depends upon the general condition and severity of the infection. Para-enteral route is preferred when the infection is acute and severe or when the patient is nutritionally or medically compromised.

With evidence of slough, gas, crepitus, and foul smell, anaerobic infection may be suspected and appropriate antibiotics have to be given.

Principles of choosing appropriate antibiotic


Flynn TR [5] in their systemic review concluded that antibiotics should be chosen which are safe and cost effective, because no one antibiotic is clearly superior to all others. In otherwise healthy patient, a 3–4-day regimen of antibiotic

**Table 21.4** Choice of empirical antibiotics (also refer Chap. 10)


therapy should be adequate. The primary importance should be given to the surgical treatment consisting of incision and drainage, extraction, or endodontic therapy of the involved tooth. According to their review, the choice of empiric antibiotics for odontogenic infections is listed in Table 21.4.

Martins JR et al. [6] suggests that after incision and drainage/removal of the cause is mandatory. Antibiotics should be administered for the shortest duration possible duration and should act as an adjuvant for the primary surgical treatment in countering any regional or systemic co-morbidities.

#### **21.8 Fluid and Electrolytes**

Apart from antibiotics and anti-infammatory drugs, administration of fuids and electrolytes is mandatory, as there is a loss of fuids due to infection and fever. In nonambulatory patients, intravenous fuids are administered depending on their systemic status.

Daily calorie requirement also increases by up to 13% for each degree rise in temperature, which needs to be addressed for a speedy recovery.

#### Supportive therapy.

It involves those modalities which aid the patient's own body defenses. It consists of the following:


#### **21.9 Selection of Anesthesia**

A simple and superfcial abscess can be drained comfortably under local anesthesia, while deep-seated, multi-loculated abcesses may not be amenable for treatment under local anesthesia and may be managed under procedural sedation provided the patient has adequate mouth-opening and patent airway.

Fiber-optic intubation or tracheostomy may be considered in; patients with limited mouth opening (trismus) or in patients having intra-oral and pharyngeal infections (sub-lingual, lateral/retropharyngeal spaces) where the chances of aspiration is high in the event of oro/naso-tracheal intubations.

#### **21.10 Spaces Around the Maxilla**

#### **21.10.1 Canine Space/Infraorbital Space**

The canine space, synonymous with Infraorbital space, is situated in the anterior surface of the maxilla at the infraorbital region above canine fossa.

#### **21.10.1.1 Source of Infection**


#### **21.10.1.2 Boundaries** (Fig. 21.2)


#### **21.10.1.3 Contents**


**Fig. 21.2** Shows boundaries of canine (infraorbital) space

#### **21.10.1.4 Clinical Features**


#### **21.10.1.5 Management**

Drainage of the space infection either intraorally or percutaneously is done; intraoral incision and drainage are preferred as these will not produce a facial scar. Drainage is made by making an in-depth incision of the maxillary vestibule near canine fossa. Sinus forceps is inserted superiorly, laterally, and medially for complete breakage of locules and drainage. Care is taken while using sinus forceps, so as to not damage the infraorbital nerve and its branches.

Aggressive antibiotic therapy is mandatory to prevent the spread as it lies in the danger area of the face and also to prevent Cavernous sinus thrombosis from septic thrombi entering into angular vein.

The involved tooth is either removed or subjected to root canal treatment with multiple dressings. Patient is advised good hydration and rest.

#### **21.10.2 Buccal Space**

The buccal space occupies the portion of the subcutaneous space present between the fascial skin, buccinator muscle, and masseter muscle [8].

Source of infection—From maxillary premolar and molar teeth root apices above buccinator attachment.

From mandibular premolar and molar teeth root apices below the buccinator attachment.

#### **21.10.2.1 Boundaries**


#### **21.10.2.2 Contents**


#### **21.10.2.3 Clinical Features**


#### **21.10.2.4 Management**

Drainage of the space infection either intraorally or percutaneously is done; intraoral incision and drainage are preferred as these may not produce a facial scar. Drainage is made by making an in-depth incision of the maxillary vestibule near the involved tooth. Sinus forceps is inserted superiorly, laterally, and medially for complete breakage of locules and drainage. Care is taken while using sinus forceps, so as to not to damage duct and artery (Fig. 21.4a, b, c).

For mandibular buccal space infection, intraoral drainage may not achieve the desired result, hence extraoral drainage at the lower border of mandible is made taking care of the facial artery and marginal mandibular nerve.

The involved tooth is either removed or subjected to root canal treatment as required. Literature advocates early extraction of the involved tooth/teeth. According to Igoumenakis D et al. [9], extraction of the involved tooth shortens the hospital stay and provides faster recovery on a biological level.

#### **21.10.3 Temporal Pouches**

Infections in this region are relatively rare to occur when involved swelling occurs at the temporal region above zygomatic arch and behind the lateral orbital rim [10]. They are two in number—*Superfcial temporal space* and *Deep temporal space* (Fig. 21.5).

#### **21.10.3.1 Superfcial Temporal Space**

This space lies between the temporal fascia and temporalis muscle.

Source of infection—From upper third molars and infection from other spaces.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 21.3** Clinical picture showing the buccal space infection

**Fig. 21.5** Shows the superfcial and deep temporal

spaces

©Association of Oral and Maxillofacial Surgeons of India


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 21.6** Clinical image of the classical dumb bell swelling (blue arrows). The isthmus of the swelling at the zygomatic arch is shown by the green arrow

#### **21.10.3.2 Boundaries**


#### **21.10.3.3 Contents**


#### **21.10.3.4 Clinical Features**


#### **21.10.3.5 Management**

Surgical drainage is carried out through an incision made above the zygomatic arch; sinus forceps is inserted through the skin incision and passed through the superfcial fascia and the temporal fascia.

#### **21.10.4 Deep Temporal Space**

This space lies between the temporalis muscle and the skull. Slightly below the level of zygomatic arch; both the superfcial and deep temporal spaces communicate with each other.

Source of Infection—Upper third molar and spread from other spaces.

#### **21.10.4.1 Boundaries**


#### **21.10.4.2 Contents**

Branches of Internal maxillary artery. Mandibular division of trigeminal nerve.

#### **21.10.4.3 Clinical Features**


#### **21.10.4.4 Management**

If the trismus is not severe, intraoral incision is given in the buccal sulcus at the second and third molar region. With the sinus forceps, the space is entered medial to coronoid process superiorly and the pus is drained. Corrugated rubber tube is placed and secured with a suture.

In case of severe trismus, extraoral incision is made above the zygomatic arch at the junction of frontal and temporal process of zygoma, sinus forceps is inserted and directed inferiorly and medially to enter the space and drain the pus. The disadvantage of this approach is that it cannot produce dependent drainage.

#### **21.11 Spaces Around the Mandible**

#### **21.11.1 Submental Space**

The infection from any of the six anterior teeth in the mandible may perforate the labial bone inferior to the mentalis muscle attachment and the pus may present at the anterior and lower border of the mandible and below the mylohyoid muscle lingually [11].

#### **21.11.1.1 Source of Infection**


#### **21.11.1.2 Boundaries** (Fig. 21.7)


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 21.7** Clinical picture showing spread of infection to the submental space and buccal space

### **21.11.1.3 Contents**


#### **21.11.1.4 Clinical Features**


#### **21.11.1.5 Management**

Transcutaneous approach in the chin region is the most effective drainage; incision is made below the symphysis menti to produce dependent drainage. Sinus forceps is inserted upward and backward to break the locules and the pus is drained. A corrugated rubber drain is inserted and secured with a suture. Intraoral approach is cumbersome as we need to pierce mentalis muscle to reach the submental space and also drainage against gravity is not possible.

### **21.11.2 Sublingual Space**

The space is V-shaped lying lateral to the muscles of the tongue and in the lingual aspect of the body of the mandible. Anteriorly communicates with submental space and posteriorly communicates with the submandibular space at the edge of the mylohyoid muscle [12].

#### **21.11.2.1 Source of Infection**


#### **21.11.2.2 Boundaries** (Fig. 21.8)

**•** Anterior: Lingual aspect of mandible.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 21.8** Shows the spread of infection to the sublingual space (grey shaded area)


#### **21.11.2.3 Contents**


### **21.11.2.4 Clinical Features**


#### **21.11.2.5 Management**


### **21.11.3 Submandibular Space**

• The submandibular space is present at the inferior border of the mandible between the anterior and posterior bellies of digastric muscles [13].

©Association of Oral and Maxillofacial Surgeons of India

#### **21.11.3.1 Source of Infection**


#### **21.11.3.2 Boundaries**


#### **21.11.3.3 Contents**


#### **21.11.3.4 Clinical Features** (Fig. 21.9)


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 21.10** Clinical pictures showing drain inserted for submandibular space infection

#### **21.11.3.5 Management**

It is managed through an extraoral approach; incision is placed at the submandibular region in the most dependent area to facilitate gravitational drainage, taking care of the facial artery and marginal mandibular nerve; a sinus forceps is inserted superiorly, medially, and laterally piercing through the superfcial fascia. A drain is inserted and secured with a suture to facilitate dependent drainage (Fig. 21.10).

#### **21.12 Masticator Space**

Masticator space is formed by splitting of the investing fascia into superfcial and deep layers. The superfcial layer lies along the lateral surface of the masseter and lower half of the temporalis. Deep layer passes along the medial surface of the pterygoid muscles before attaching to the base of the skull superiorly.

The masticator spaces comprise the following four spaces:


#### **21.12.1 Submasseteric Space**

Masseter consists of three layers which are frmly attached anteriorly and loose posteriorly. The space is present lateral to ascending ramus of the mandible.

#### **21.12.1.1 Source of Infection**


#### **21.12.1.2 Boundaries**


#### **21.12.1.3 Clinical Features**


#### **21.12.1.4 Management**

The drainage of the infection is done through two approaches.

In intraoral approach, incision is placed at the retromolar area along the anterior border of the ramus of mandible. The sinus forceps is inserted through the incision laterally between the mandibular ramus and the masseter muscle to explore the Submasseteric space. The disadvantage of intraoral technique is that incision and drainage is not gravity dependent.

In extraoral approach, the incision is placed on the skin at the angle and inferior border of the mandible; sinus forceps is inserted directing superiorly piercing the subcutaneous tissue and masseter muscle. Abscess drained corrugated rubber tube is placed and secured with a suture. Precautions are taken not to damage the marginal mandibular nerve (Figs. 21.11 and 21.12).

#### **21.12.2 Pterygomandibular Space**

One of the most frequently encountered space in dental offce is pterygomandibular space [14].

#### **21.12.2.1 Source of Infection**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 21.12** Clinical picture showing submasseteric space infection left side, pus was drained extraorally

©Association of Oral and Maxillofacial Surgeons of India


#### **21.12.2.2 Boundaries**


#### **21.12.2.3 Contents**


#### **21.12.2.4 Clinical Features** (Fig. 21.13)


#### **21.12.2.5 Management**

Generally, incision and drainage are done through intraoral approach; however, in case of severe trismus, extraoral approach may be indicated. Drainage is done either under general anesthesia or by giving mandibular nerve block.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 21.13** Clinical picture of left pterygomandibular space infection forming a decayed impacted lower left third molar. Note the limited mouth opening

#### **Intraoral Approach**

A vertical incision of 1.5 cm is made at the anterior and medial aspect of the mandible, sinus forceps is inserted into the abscess cavity, and pus is evacuated. Corrugated rubber drain is inserted and sutured to the margins of the incision to prevent dislodgement.

#### **Extraoral Approach**

In case of severe trismus, this approach is advised, an incision of 1.5 cm is made on the skin, toward the inner aspect of the angle region. Sinus forceps is inserted toward the medial aspect of the mandible directing superiorly close to the bone. Pus is evacuated and rubber drain is inserted and sutured to the margins of the incision.

Figure 21.14 shows various approaches which can be used for fascial space infections and Fig. 21.15 shows submandibular approach to the medial and lateral masticator spaces.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 21.14** Shows the extraoral incisions for the space infections, (**a**) temporal space, (**b**) submental space, (**c**) submandibular space, (**d**) lateral pharyngeal space, (**e**) retropharyngeal space

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 21.15** Diagrammatic representation of the approach to the pterygoid space (medial) or massetric space (lateral) via submandibular incision

#### **21.13 Spaces of Neck**

#### **21.13.1 Parapharyngeal Spaces**

The spaces around the pharynx form a 'Ring' and a pathway for spread of infections from the orofacial region to the neck and mediastinum. The Parapharyngeal space includes Lateral Pharyngeal space and Retropharyngeal space.

#### **21.13.2 Lateral Pharnygeal Space**

It is a potential space lying lateral to the pharynx, extending from base of the skull to the hyoid bone. The space is conical in shape, base being toward the base of the skull and apex toward the hyoid bone.

#### **21.13.2.1 Source of Infection**


#### **21.13.2.2 Boundaries**


#### **21.13.2.3 Contents**


#### **21.13.2.4 Clinical Features**


#### **21.13.2.5 Management**

A combination of intra-oral and extra-oral approaches are advised for the managment of infections of the lateral pharyngeal space. They are preferably done under general anesthesia with care taken to secure the airway.

*Intraoral approach*—A 1.5 cm incision is made on the Pterygomandibular raphe, sinus forceps is passed through the raphe on the medial surface of the mandible, medial aspect of the medial pterygoid muscle, and lateral aspect of the superior constrictor muscle.

*Extraoral approach*—An incision of 2.5 cm is made in the submandibular region, blunt dissection is then carried through the fascia just anterior to the sternocleidomastoid muscle, and digital palpation can enter and dissect the lateral pharyngeal space bluntly (Fig. 21.16). The landmarks to be palpated are the angle of the mandible anterolaterally, the carotid sheath posterolaterally, the transverse processes of the cervical vertebrae posteromedially, and the endotracheal tube, if present, anteromedially. Caution must be taken not to perforate the posterior oropharyngeal wall by aggressive fnger dissection toward the oropharynx [15].

*Combined approach*—Intraoral incision is made on the mucosa at the medial aspect of the ramus of the mandible, curved hemostasis is inserted lateral to superior constrictor muscle and medial to medial pterygoid muscle and the blunt dissection is carried out posterio-inferiorly below the angle of the mandible. The tip of the instrument is palpated at the anterior border of the sternocleidomastoid muscle extraorally and cutaneous incision is made over the tip. A drain is inserted and sutured to the wound margin to allow drainage.

Maintaining the endo-tracheal tube or tracheostomy may be considered depending on the severity of infection and the success of drainage.

#### **21.13.3 Retropharyngeal Space**

It is also called as prevertebral space, which is a potential space present in the midline between the pharyngobasilar **Fig. 21.16** Shows the approach for the retropharyngeal space infection

©Association of Oral and Maxillofacial Surgeons of India

fascia and prevertebral fascia. This space is continuous with retropharyngeal space into the posterior mediastinum.

#### **21.13.3.1 Source of Infection**


#### **21.13.3.2 Boundaries**


#### **21.13.3.3 Contents of the Space**

• Lymph nodes.

#### **21.13.3.4 Clinical Features**


#### 6. Dyspnea.

7. Mediastinitis is the most feared complication of this space.

#### **21.13.3.5 Management**

Most important is to secure airway, may be an elective tracheostomy or fber optic intubation is considered for airway maintenance.

Intraoral approach is generally done for the suprahyoid part of the retropharyngeal infection, procedure is similar to the one done for lateral pharyngeal space infection. Intraoral incision is made on the mucosa at the medial aspect of the ramus of the mandible, curved hemostat is inserted lateral to superior constrictor muscle and medial to medial pterygoid muscle, and the blunt dissection is carried out further inferiorly.

Extraoral approach is better for the infection at the infrahyoid region, incision is made transcutaneously anterior to the sternocleidomastoid muscle at the level of the angle of the mandible to the level of the hyoid bone. Both sternocleidomastoid muscle and Carotid sheath are identifed, and retracted. Blunt dissection is carried out into lateral and retropharyngeal spaces, later being verifed by the palpation of anterior process of the cervical spine posteriorly and the endotracheal tube anteriorly [16]. Drain is placed and secured to the edges of the cutaneous incision.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 21.17** Shows the boundaries of peritonsillar abscess

#### **21.13.4 Peritonsillar Abscess: (Quincy)**

It is a localized infection near the tonsils, usually occurring as a secondary infection from the local sites.

#### **21.13.4.1 Source of Infection**


#### **21.13.4.2 Boundaries**


#### **21.13.4.3 Clinical Features**


#### **21.13.4.4 Management**

Intraoral approach, superfcial incision made at the most prominent area of the swelling near anterior pillar and the soft palate, sinus forceps is inserted deep into the tissues to break all the locules and drain the pus [17].

### **21.14 Sequelae of Space Infections, if Ignored**

Possible life-threatening complications may be developed if the space infections of the jaws are not addressed adequately; for ease of understanding, the complications are classifed as follows (Table 21.5).

**Specifc warning signs in space infections include:**


#### **21.14.1 Ludwig's Angina**

It was frst described by Wilhelm Friedreich Von Ludwig in 1836, and the term Ludwig's Angina was coined by Camerer in 1937. The word Angina is derived from Latin language meaning suffocation or choking.

Ludwig's Angina is defned as an acute, frm, nonsuppurating, necrotizing cellulitis involving bilateral Submandibular, Sublingual, and Submental spaces. The condition has been described by medical practitioners, by three unique features, starting with the alphabet 'F'—Feared, Fluctuant rarely, Fatal often.

Many terminologies were used for this condition like Marbus Strangularis, Angina Maligna, and Garotillo.

**Table 21.5** Sequelae of space infections if ignored


#### **21.14.1.1 Source**

Predominantly (90%) odontogenic in origin, from the lower jaw.

Infection from 2nd and 3rd molar teeth may be Acute dentoalveolar abscess, Periodontal Abscess.


#### **21.14.1.2 Predisposing Factors**


#### **21.14.1.3 Clinical Features** (Table 21.6)

The infection of the sublingual space rapidly spreads along to its base which is present at the hyoid bone. A characteristic feature is edema of the epiglottis and the vocal cords, due to the spread of infection in a postero-inferior direction from

#### **Table 21.6** Clinical features of Ludwig's angina


the sub-lingual space to the laryngeal inlet. This may produce acute respiratory obstruction and death [18].

#### **21.14.1.4 Management**

It should be treated as life-threatening situation and intervened aggressively

The treatment of Ludwig's Angina is primarily surgical. The frst priority in the management is always the life-saving measure. If the patient shows any signs of dyspnea, Tracheostomy should be performed promptly

Treatment protocol is as follows:


Endotracheal intubation is nearly impossible due to trismus, tongue elevation, and laryngeal edema. A skilled anesthetist with fber optic laryngoscope may try Nasoendotracheal intubation, while the patient is conscious and awake, while the tracheostomy kit is kept on standby, in case of emergency (please refer Chap. 7 to read about anesthesia procedures in patients with space infections).

Once the airway is secure, the next step is surgical decompression of spaces and tissue planes; this is achieved by giving multiple cutaneous incisions in the submandibular and submental regions. Decompression of sublingual space is very important, which is achieved by piercing the mylohyoid muscle. This can also be achieved by placing an incision in the foor of the mouth, parallel to the lingual vestibule. There may not be much pus to drain as the condition is usually non-supperative (Fig. 21.18a, b, c). Corrugated rubber drain may be left in situ to keep the incisions patient and to drain the exudates [19]

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 21.18** (**a**, **b**, **c**) Clinical pictures showing the drainage of Ludwig's angina

Purpose of decompression is threefold:


After decompression, simultaneous removal of the cause is important, as this is the source of the condition.

Intravenous fuids are administered to maintain proper fuid and electrolyte balance and to fulfll the nutritional requirement of the patient. Defnitive antibiotics are given intravenously based on the culture and sensitivity reports. Other symptomatic medicines like anti-infammatory and analgesics may be prescribed. Local wound care is taken care of by irrigation and dressings. Drains to be changed every 48 hrs and maintained until the condition resolves.

#### **21.14.2 Necrotizing Fasciitis**

Necrotizing fasciitis is an uncommon soft tissue infection, occurs due to polymicrobes and spreads rapidly in the subcutaneous tissue and above superfcial fascia, and as the disease progresses, muscle and skin involve giving rise to myonecrosis. The other name for this condition is Hospital Gangrene given by Brooks in 1966 and Hemolytic streptococcal gangrene. Necrotizing fasciitis may affect any part of the body; however, it most commonly affects the extremities, abdominal wall, and the perineum following trauma or surgery.

The condition shows no clear boundaries or palpable limits, mainly occurs with immunocompromised patients and those suffering from systemic illnesses (Fig. 21.19).

#### **21.14.2.1 Source**

The causative organisms in this condition are multiple like Aerobic Group A—hemolytic Streptococcus and Staphylococcus and later identifed microbes are Bacteroids, Proteus, coliforms, and peptostreptococcus. In most cases, the pathogens gain entry through disruption of the skin caused by trauma or surgery. Continuous bacterial overgrowth and synergy cause a decrease in oxygen tension and develop local ischemia and proliferation of anaerobic bacteria. The fulminating nature of the necrotic process is the result of the symbiotic relationship between the bacteria.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 21.19** Clinical picture showing the necrotizing fasciitis

**Table 21.7** Clinical features of necrotizing fasciitis


#### **21.14.2.2 Clinical Features** (Table 21.7)

#### **21.14.2.3 Investigations**


#### **21.14.2.4 Management**

Early recognition and aggressive surgical intervention is mandatory; taking the medical parameters into consideration and airway maintenance, general anesthesia is preferred in most cases.

Initially, intravenous broad spectrum antibiotics are administered to control the spread of the infection; these antibiotics may be changed once the culture report is obtained.

Surgical treatment is obligatory with incision and drainage, in addition to vigorous debridement of the necrotic fascia, subcutaneous tissue, muscle, and skin. Excision of tissue to the point of fresh bleeding is advised. Multiple and regular change of dressings are needed till the condition is resolved.

Some centers may follow Hyperbaric oxygen therapy for this condition.

#### **21.14.3 Cavernous Sinus Thrombosis**

Cavernous sinuses are the venous sinuses situated on either side of the sella tursica. The cavernous sinus on either side communicates freely with each other by anterior and posterior intracavernous sinuses they also communicate with sagittal sinus, transverse, sinus and sigmoid sinus. The cavernous sinus communicates extra cranially with veins of the head and neck.


*External route*—Infection from face and lips carried by facial and angular veins and nasofrontal veins to the superior ophthalmic vein passes through the superior orbital fssure and enters the cavernous sinus.

*Internal route*—Infection from the posterior maxillary region to the pterygoid plexus to the inferior ophthalmic vein through the inferior orbital fssure and then through the superior orbital fssure to the cavernous sinus.

#### **21.14.3.1 Source**

The area of the face between the inner canthus of the eyes and the corners of the mouth is called `Danger Triangle` of the face and any kind of severe sepsis in this area can spread in a retrograde manner and can extend to the cavernous sinus through the angular vein and ophthalmic vein.

Causative agents identifed are Streptococcus, Staphylococcus, and Gram negative microbes.

#### **21.14.3.2 Clinical Features**


#### **21.14.3.3 Eagleton Criteria**

Diagnostic criteria were suggested by Eagleton, prior to modern investigative methods.


#### **21.14.3.4 Management**

The patient should be given broad spectrum intra venous antibiotics preferably those which cross the blood brain barrier. Aminoglycosides and Clindamycin are started in high therapeutic doses. IV Mannitol is given to decrease the intra cranial pressure. Anticoagulant Heparin 20,000 units in 1500 ml of 5% Dextrose is advised to reduce thrombosis.

Neurosurgical intervention is mandatory.

#### **21.14.4 Meningitis**

It is one of the neurological complications resulting from the infection of oro-facial region. It may develop from metastatic spread or may be due to nearby thrombophlebitis.

#### **21.14.4.1 Clinical Features**


#### **21.14.4.2 Diagnosis**

Diagnosis is based on cerebrospinal fuid analysis. In CSF polymorpho-nuclear leukocytes, elevated protein levels and decreased glucose levels are noticed.

#### **21.14.4.3 Treatment**

– Initially with Chloramphenicol 4 g/day-IV associated with Penicillin G 24 million units per day IV


Maintenance of hydro-electrolyte balance is recommended. Change of antibiotics if required after culture and sensitivity report.

#### **21.15 Conclusion**

Odontogenic infections are typically polymicrobial. The pathogenesis of odontogenic infections depend on a synergistic relationship between aerobic and anaerobic bacteria.

The last decade showed a notable change in the behavior of odontogenic infections. The severity of these infections is far greater than in the past, demanding swift recognition of the disease followed by prompt and more aggressive treatment. Failing to identify and treat these infections promptly may result in disastrous outcomes.

Defnitive treatment includes airway management, adequate resuscitation and optimization of pre-existing medical conditions prior to removal of the source of infection, and drainage of pus.

Oral and high-dose intravenous antibiotics should be administered as required depending on the severity of infection and based on the decision whether the patient is treated on an outpatient or inpatient basis, with the initial choice of antibiotics modifed in the light of subsequent bacteriological reports. The treatment of all odontogenic infections must include removal of the focus of infection and drainage of pus.

#### **References**


#### **Additional Suggested Reading**

Flynn TR. Oral and maxillofacial infections: 15 unanswered questions. Oral Maxillofac Surg Clin North Am. 2011 Nov;23(4):ix–x.

**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

**22**

## **Osteomyelitis, Osteoradionecrosis, and Medication-Related Osteonecrosis of Jaws**

Christian Walter and Christoph Renné

#### **22.1 Introduction**

Bones belong to the connective tissue. Their main function is the internal support and source of inorganic ions. Bones have an organic matrix that is secondarily calcifed with calcium salts, mainly hydroxyapatite. The organic matrix consists of a huge extent of type I collagen. Only 5% are other proteoglycans and non-collagenous proteins [1].

There are two major bone parts: The outer compact and the interior cancellous part. In the compact bone, the collagen fbrils form concentric lamellae around a central canal that is called the Haversian canal. These canals harbor vessels which are interconnected by further vessels lying in the Volkmann's canals. The fbrils in neighboring lamellae have a perpendicular orientation resulting in higher stability of the bone. In between the calcifed lamellae are therefore concentric orientated osteocytes. Their main function seems to be the mineralization of the bone [1]. The compact bone is responsible for approximately 80% of the entire bone weight [2]. The main function of the compact bone is mechanical stability whereas the cancellous bone mainly has a metabolic function [1]. The cancellous bone consists of small lamellae and has a surface 10 times bigger than the compact bone [2]. On the outside of the compact bone is the periosteum, on the inside the endosteum.

There are three kinds of bone cells: The osteoblasts, the osteocytes, and the osteoclasts.

C. Walter (\*)

Oral and Maxillofacial Surgery – Plastic Surgery, Mediplus Clinic Mainz, Mainz, Germany e-mail: walter@mainz-mkg.de

#### **22.1.1 Osteoblasts**

Osteoblasts derive from a multipotential stem cell that differentiates via an osteoprogenitor cell into osteoblasts. Osteoblasts form new bone by the production of the inorganic matrix that mineralizes eventually. After a cycle of bone resorption and consecutive bone formation, most osteoblasts become lining cells covering the surface of the bone [1].

#### **22.1.2 Osteocyte**

During the course of bone formation, approximately 10% of the osteoblasts build themselves into the bony structure and become osteocytes [2]. It is assumed that the number of osteocytes is 10 times higher than the number of osteoblasts in the adult human body. The osteocytes are stellate cells that have lots of slim processes that are connected to surrounding cells. Osteocytes with their three-dimensional network seem to play the key role in bone remodeling [1].

#### **22.1.3 Osteoclast**

From all bone cells osteoclasts represent the smallest fraction. Osteoclasts are multinucleated giant cells that resorb bone. They derive from the monocyte macrophage line. Their only function is to resorb mineralized tissue as it is necessary for bone growth, remodeling, and tooth eruption. Most bone diseases are associated with an increased function of the osteoclasts. Therefore, osteoclasts are often the pharmaceutical target in the therapy of bone diseases such as malignancies or metabolic diseases as osteoporosis. Osteoclasts are regulated by the RANK RANKL OPG system [1, 3].

C. Renné

Group Practice for Pathology Wiesbaden, Wiesbaden, Germany

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 461

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_22

#### **22.1.4 RANK RANKL OPG**

The receptor activator of nuclear factor κB ligand (RANKL) is an osteoclast differentiating factor mainly expressed by osteoblasts. Secretion of RANKL leads to the differentiation of osteoclasts out of precursor cells, and the activation of osteoclasts to resorb bone by binding on RANK that is expressed on both the precursor cells and the mature osteoclasts. Osteoprotegerin (OPG) is the osteoclastogenesis inhibitor factor and functions as a decoy receptor for RANKL so that the osteoclasts cannot be activated. The RANK RANKL OPG system seems to be the most important part in the communication between the bone cells.

This system is not exclusively organizing the communication between osteoblasts and osteoclasts. This system has been proven to be responsible for the formation of the mammary gland and lymph nodes. RANK and RANKL are also expressed in the kidney, spleen, thymus, and brain, where it might infuence the thermoregulation [3].

#### **22.2 Osteomyelitis**

The clinical picture of the different kinds of osteomyelitis is very inhomogeneous so that there are many defnitions and classifcations. In textbooks, the osteoradionecrosis and medication-associated osteonecrosis of the jaws are often subentities of the osteomyelitis. In this book, these entities are described in their own subheadings (Sects. 22.3 and 22.4 of the chapter).

#### **22.2.1 Defnition**

The actual term "osteomyelitis" refers to an infammation ("itis") of the bone marrow ("osteomyel") only but means an infammation of the entire bone including the periosteum, the cortical, and cancellous bone as well as the bone marrow.

#### **22.2.2 Classifcation**

There are many different classifcations that are either based on the etiology, pathogenesis, pathologic or anatomic differences, the clinical course of the disease, or radiologic patterns. This makes a comparison between different studies very complicated or impossible.

The Zürich classifcation [4] differs between three different kinds of osteomyelitis: The *acute osteomyelitis*, the *secondary chronic osteomyelitis,* and the *primary chronic osteomyelitis* (Table 22.1). The secondary chronic osteomyelitis results from the acute osteomyelitis and therefore is **Table 22.1** The table describes the Zürich classifcation of osteomyelitis on the left-hand side. In the right column are the different kinds of osteomyelitis that are included in the respective group of the Zürich classifcation [4]


the same disease at a different time stage. Once the osteomyelitis persists for more than 4 weeks, it is defned as chronic [4].

#### **22.2.3 Epidemiology**

Due to the different classifcations and terms used for the entire group of osteomyelitis, it is hard to give general data regarding its epidemiology. Approximately 17% of all osteomyelitis cases belong to the group of the acute osteomyelitis, 70% to the secondary chronic osteomyelitis, and 10% to the primary chronic osteomyelitis [4]. The average age at the time of diagnosis is a little bit over 40 years for the acute and the secondary chronic osteomyelitis [4]. Because of the inhomogeneity of the secondary chronic osteomyelitis, a general age group cannot be given.

#### **22.2.4 Etiology**

In the etiology of the *acute osteomyelitis* and the *secondary chronic osteomyelitis,* usually an odontogenic infection can be identifed such as a dead tooth, a periodontal disease, or conditions after dentoalveolar surgery. A hematogenic spread from a different primary location into the region of the jaws is extremely rare [4].

The etiology of the *primary chronic osteomyelitis* is an infection of unknown origin [4].

#### **22.2.5 Pathogenesis**

The acute osteomyelitis and secondary chronic osteomyelitis are caused by a local infection due to bacteria from the oral cavity. The likelihood of the development of the infection depends on the virulence and number of bacteria and the quality of the local immune response and the blood fow [4].

Therefore, general diseases affecting the immune system are risk factors in the development of osteomyelitis, e.g., diabetes, autoimmune diseases, or anemia.

A typical course of the acute and secondary chronic osteomyelitis is the contamination of the bone with bacteria. The bacteria proliferate and colonize the bone marrow and reach via the Haversian and Volkmann canals the periosteum. The edema under and in the periosteum disturbs the blood fow resulting in ischemic bone parts and potentially sequestrum building.

#### **22.2.6 Histology**

The *acute osteomyelitis* and the *secondary chronic osteomyelitis* are characterized by an infammatory exudate, primary in the medullary spaces with fbrin, leucocytes, and macrophages that replace the fatty tissue and hematopoietic marrow (Fig. 22.1). In addition, necrotic debris and bacteria can

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 22.1** In this case of acute osteomyelitis, the medullary hematopoietic cells and the fatty tissue are completely replaced by cell debris, fbrin, and an infammatory infltrate mainly composed of neutrophil granulocytes (black arrow). Besides the vital bone with flled lacunes of osteocytes (yellow arrow), necrotic bone can be seen with loss of osteocytes (blue arrow)

be found [4, 5]. The most common bacteria being detected is *Staphylococcus aureus* (85%) [4]. Due to the blood fow disturbances (see pathogenesis), parts of the bone die so that empty osteocytic lacunae can be observed. Sequestrae may be present. New bone formation under the periosteum is not uncommon.

In cases of secondary chronic osteomyelitis, sequestrum formation is more common than in the acute osteomyelitis. The more chronic the course is, the more likely is the development of bone marrow fbrosis and sclerosis of the bone. Bacteria might be present. Actinomyces drusen are typical.

In the *primary chronic osteomyelitis,* plasma cells are predominant in the infammatory infltrate. The proportion of neutrophils, lymphocytes, and macrophages is rather small. The bone marrow is altered due to fbrosis. New bone formation is a common sign. Osteoclastic activity leads to repeated bone remodeling without a distinct histological bone formation pattern. Microabscesses might be observed [4].

#### **22.2.7 Symptoms**

In cases of *acute osteomyelitis,* patients present with high fever and are listless. Local swelling can be observed with pain on palpation. The affected area is reddish, a trismus might be present, and quite often the teeth have higher mobility with pus coming out of the periodontium. If the inferior alveolar nerve is affected, patients report paresthesia of the lips (Vincent symptom [4]). There are cases in which the symptoms are not very distinctive.

Symptoms of the *secondary chronic osteomyelitis* are the painful swellings that are usually not as prominent as in the acute osteomyelitis. A common fnding is a periosteal reaction causing a solid swelling. Further symptoms are sequester formation and fstulas.

The *primary chronic osteomyelitis* is characterized by a nonsuppurative infammation and sometimes only barely noticeable symptoms. In active periods, the patients notice pain, swelling, and mouth-opening limitations. Due to the bone formation, permanent swelling will develop eventually [4].

#### **22.2.8 Complications**

A typical complication of the acute osteomyelitis is a shift into the chronic osteomyelitis that is very hard to treat suffciently.

Further complications are the development of the Vincent syndrome, fstula, abscess and sequester formation, and potentially fractures [4].

#### **22.2.9 Diagnosis**

The diagnosis is based on the clinical course. This is completed by radiology: panoramic radiograph, cone beam CT, CT, or MRI. Changes in the bone can only be seen after a 30 to 40% reduction of the mineralized part of the bone. Therefore, the changes in the acute osteomyelitis are marginal at the beginning. In complex cases of osteomyelitis, a bone scintigraphy might be used to detect further active spots in the skeleton, e.g., in the diagnosis of chronic recurrent multifocal osteomyelitis or the SAPHO syndrome (SAPHO: Synovitis, acne, pustulosis, hyperostosis, osteitis) [6].

Radiological signs of *acute osteomyelitis* are: Bone resorption with increased radiolucency, loss of spongious structure of the bone, potentially sequester formation.

Radiological signs of the *secondary chronic osteomyelitis* are: Bone resorption with increased radiolucency, sequester formation, periosteal reaction, and pathological fractures.

Radiological signs of the *primary chronic osteomyelitis* are: Increased radiopacity with loss of trabecular bone, bone resorption, and periosteal reaction (Fig. 22.2) [4].

#### **22.2.10 Diferential Diagnoses**

In the differential diagnosis, one should rule out malignancies in unclear cases so that biopsies should be performed.

#### **22.2.11 Therapy**

The therapy of the acute and secondary chronic osteomyelitis mainly consists of the therapy of the infection and of the improvement of the local blood fow. This is achieved via antibiotics and removing of the infected parts of the bone. A decortication supports this and helps to get well-vascularized tissue onto the bone.

*Acute osteomyelitis* is immediately treated with antibiotics. If an antibiogram suggests different antibiotics, an adaptation should be performed after the initial antimicrobiological therapy. Mouth rinses, hygiene, and cold application can be applied. In general, the highly mobile teeth should not be extracted since they will gain stability again after the acute stadium of the osteomyelitis is over.

The therapy of the *secondary chronic osteomyelitis* aims at suffcient pain management, limitation of the spread of the affected areas, fracture prevention, and the prevention of the onset of further active periods. Secondary diseases such as diabetes need to be treated as well.

The therapy of the *primary chronic osteomyelitis* consists of a surgical intervention to remove the necrotic bone parts and a potential disfgurement can be corrected. But recurrences of the symptoms are very common. Therefore, other treatment options should be used as well including antibiotics, nonsteroidal anti-infammatory drugs (NSAIDS), steroids, and bisphosphonates (mainly pamidronate).

#### **22.2.12 Prognosis**

The therapeutic success is higher in patients with acute and secondary chronic osteomyelitis than in patients with primary chronic osteomyelitis. Approximately 75% of the acute and secondary chronic osteomyelitis are symptom-free after intervention whereas only about 25% are symptom-free of the patients with primary chronic osteomyelitis [4].

**Fig. 22.2** Panoramic radiograph of a patient with primary chronic osteomyelitis after several surgeries have been performed. Several infusions of pamidronate prevented the occurrence of further active periods. In the left mandible, typical sclerosis can be seen with a prominent nerve canal

©Association of Oral and Maxillofacial Surgeons of India

#### **22.3 Osteoradionecrosis**

The osteoradionecrosis is a side effect in the therapy of malignant diseases to the head and neck area with ionizing radiation.

#### **22.3.1 Defnition**

Osteoradionecrosis describes the exposed necrotic bone due to radiation. The infected osteoradionecrosis describes the additional infection of the necrotic bone [7].

#### **22.3.2 Epidemiology**

The prevalence of osteoradionecrosis ranges from 0 to 23% of the patients with head and neck radiation [8]. Usually, older patients are affected (60 years ±10 years) since the primary disease causing the head and neck radiation are diseases in patients with advanced age [9]. Men are affected more than twice as often [9].

#### **22.3.3 Etiology**

The etiology of the osteoradionecrosis is radiation therapy to the head and neck area. Usually, another trigger is required in the development of the osteoradionecrosis (see pathogenesis).

#### **22.3.4 Pathogenesis**

Due to the radiation therapy, the vessels of the bone change and become hyalinized. It results in a lack of nutrition and hypoxia with the subsequent death of osteocytes [7]. This seems to be more likely in radiation doses above 40–50 Gy [10]. The radiation has additional side effects to all tissues being in the radiation feld including the skin, the muscles, and the salivary glands. Due to the resulting xerostomia radiation, caries develops so that an osteoradionecrosis might develop.

The osteonecrosis occurs more often in the mandible most probably to the greater extent of cortical bone and the more critical vascularization of the mandible. And the mandible most probably is more often in the radiation feld due to the location of the primary tumor [10].

There are several risk factors that are associated with a more frequent occurrence of the osteoradionecrosis. Those are male gender, insuffcient oral hygiene, pressure denture sores, a tumor localized in the tongue, alveolar process of the mandible, the foor of the mouth, and retromolar as well as persisting alcohol and nicotine consumption. Next to these, there are therapy-linked risk factors, namely a tumor resection including resection of the bone and dentoalveolar surgery performed in timely proximity to the radiation therapy [10].

#### **22.3.5 Classifcation**

It is mainly differed between the aseptic osteoradionecrosis and the infected osteoradionecrosis. Another very common staging system uses the potential beneft of a rather controversially discussed therapy option the hyperbaric oxygen treatment and therefore won't be discussed in further detail.

#### **22.3.6 Histology**

The lacunae of the osteocytes in osteoradionecrotic bone are empty (Fig. 22.3). There is a lack of osteoblastic rimming and the Haversian and Volkmann canals do not harbor any blood vessels. The marrow of the bone shows acellular collagen. The periosteum is acellular and avascular [5].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 22.3** The examination of the osteoradionecrosis under the microscope shows avital bone with irregular fssured borders. The lacunae of the osteocytes are empty without osteocyte cell nuclei (black arrows) and also the blood vessels in the Haversian canals have undergone necrosis, so that only empty spaces are the visible remnants (yellow arrow). The necrotic bone is missing the osteoblastic rimming (green arrow). The bone marrow is replaced by a collagen fber-rich scar like connective tissue (red arrow)

#### **22.3.7 Symptoms**

Symptoms are the exposed necrotic bone that can be visible or palpable with a probe. Further symptoms are pain, swelling, the development of granulation tissue, foetor ex ore, oral and extraoral fstulas, potentially increased mobility of the adjacent teeth, altered sensibility, and occlusion [10].

#### **22.3.8 Complications**

Main complications are extended infections of the site, the development of fstulas, and pathological fractures. This might result in resections of the altered bone including the loss of the continuity of the bone or the opening of the nasal cavity or sinus. This results in a reduced masticatory function. Due to the fbrosis of the soft tissues, trismus might occur. All these factors lead to a reduced quality of life [10].

#### **22.3.9 Diagnosis**

The diagnosis is a clinical one. There needs to be a mandatory head and neck radiation and the exposed necrotic bone.

Typical radiologic fndings are bone destruction, altered bone density, the occurrence of sequestra, and pathological fractures.

#### **22.3.10 Diferential Diagnoses**

Differential diagnoses are osteomyelitis and the medicationassociated osteonecrosis of the jaws as well as the existence of malignancy so that a histological sample should be assessed.

#### **22.3.11 Therapy**

As already mentioned, the evidence of the use of hyperbaric oxygen treatment is rather low and is not recommended [11, 12]. Smaller necrotic areas can be treated conservatively using antiseptic mouth rinses, antibiotics, and pain killers. In some cases, a wait and see strategy is reasonable. Sometimes circumscribed debridement might be performed. Extended necrotic areas should be surgically removed [13]. The aim is to preserve damage to the alveolar nerve and to avoid a continuity defect of the mandible. The operation should be as atraumatic as possible. The periosteum should not be removed if possible. The necrotic areas should be removed, sharp edges need to be smoothened, and the bone should be covered with soft tissue. The surgery should be performed with perioperative antimicrobial therapy.

#### **22.3.12 Prognosis**

The risk for a recurrence of an osteoradionecrosis is high. Pressure denture sores, wound healing defciencies, and mucositis are risk factors for a recurrence.

#### **22.3.13 Prevention**

A 3D-planning of radiation therapy might help to reduce the radiation doses in the bone. In addition, a splint inserted in the patient's mouth during the radiation might help to reduce the burst of the local mucosal membranes due to secondary radiation that might occur due to metallic dental restorations. An additional splint to provide fuorides to strengthen the teeth might help prevent the development of radiation caries.

It is feasible to reduce the existence of risk factors that might later on trigger the development of an osteoradionecrosis. Therefore, an initial dental checkup and therapy preceding the radiation therapy should be performed including the extraction of all non-restorable teeth. The patient should be motivated for exceptional good oral hygiene [10].

#### **22.4 Medication-Associated Osteonecrosis of the Jaws**

There are several pharmaceutical agents that cause osteonecrosis of the jaws. In the following, the main focus will be on the bisphosphonate-associated osteonecrosis.

#### **22.4.1 Bisphosphonate-Associated Osteonecrosis of the Jaws**

#### **22.4.1.1 Bisphosphonates**

Bisphosphonates are used in patients with an increased osteoclastic activity due to malignancy such as solid tumors with osseous metastases or the multiple myeloma or due to metabolic bone diseases such as osteoporosis. The main target of bisphosphonates that can be administered orally of IV is the osteoclasts.

Bisphosphonates are classifed into nitrogen- and nonnitrogen-containing bisphosphonates. The non-nitrogencontaining bisphosphonates are built into ATP and can no longer be used as a source of energy in the cells. The nitrogen-containing bisphosphonates inhibit the farnesyl pyrophosphate synthase in the mevalonate pathway leading to decreased osteoclastic function [14]. In 2003, the bisphosphonate-associated osteonecrosis was frst mentioned in a scientifc paper [15].

#### **22.4.1.2 Defnition**

The bisphosphonate-associated osteonecrosis is defned as the occurrence of the necrotic bone of the jaws that has been persistent for at least 8 weeks with a current or previous history of bisphosphonate use (Fig. 22.4). Furthermore, it is demanded that the patient had had no former head and neck radiation [16].

The last demand seems arbitrary since the coexistence of a further risk factor simply increases the risk of osteonecrosis development so that there is a special risk constellation. There is evidence that it is even possible to histologically distinguish an osteonecrosis derived from bisphosphonates compared to osteoradionecrosis [17].

#### **22.4.1.3 Epidemiology**

The prevalence and incidence of the bisphosphonateassociated osteonecrosis of the jaws depend on the primary disease, comedication, and the existence of local trigger factors. The highest risk is present in oncologic patients with

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 22.4** Huge bisphosphonate-associated osteonecrosis of the left maxilla in a patient with non-Hodgkin lymphoma and a zoledronate treatment for 2.5 years before a pressure denture sore triggered the osteonecrosis

further compromising medications. Incidences for patients with malignant diseases range from 1 to 20% [18–20]. The prevalence of secondary osteoporosis is about 1% and for primary osteoporosis 0.1% [21]. There is only a small difference between the genders. Women are affected a little bit more often than men. Most probably due to the osteoporosis and breast cancer cases vs. the prostate cancer cases that exclusively occur in men. The average age is approximately 60 years ±10 years (standard deviation) [9].

#### **22.4.1.4 Etiology**

The main factor is the use of nitrogen-containing bisphosphonates. Administered bisphosphonates will be incorporated in the bone. It is unclear if and how long these bisphosphonates are active. The development of bisphosphonate-associated osteonecrosis can be triggered by oral factors—this is usually a wound in the oral cavity: periodontal disease, surgical procedures, etc. [9, 22].

#### **22.4.1.5 Pathogenesis**

The main target of the bisphosphonates is the osteoclast, thereby inducing reduced bone remodeling. Due to the unspecifc interaction with cells, not only the osteoclasts are affected, but also, in lower concentrations, osteoblasts are stimulated [23]. The effect is an increase in total bone. Other affected cell lines are blood vessel cells, fbroblasts, and keratinocytes. The antiangiogenic function of bisphosphonates [24, 25] leads to decreased vascular exploitation [26]. This results in fewer potentially less potent vessels that have to support more bone. In addition, the soft tissues covering the bone are affected by the bisphosphonates so that potential wounds are less prone to heal [24]. In older articles, it is often described that tooth extractions are responsible for the development of the bisphosphonate-associated osteonecrosis of the jaws. This theory might not be right. It is more likely that these teeth have been extracted too late since they were extracted out of an alreadyexisting, altered, infected, or necrotic bone [27].

#### **22.4.1.6 Classifcation**

The bisphosphonate-associated osteonecrosis of the jaws is classifed into several different stages. At-risk patients are all those receiving bisphosphonates.

Stage 0 patients are patients that do have some symptoms without any visible uncovered bone. Stage I, the necrotic bone becomes visible. Patients in this stage usually do not have any symptoms. Stage II, an additive infection is existent.

Stage III, further complications occur such as necrotic areas involving the base of the mandible or the sinus or pathologic fractures are existent [16].

#### **22.4.1.7 Histology**

Usually, there is a mucosal damage above the necrosis, perhaps some granulation tissue (Fig. 22.5). The necrotic bone is often avascular and covered in bacteria, especially Actinomyces (Fig. 22.6) [28]. The osteonecrotic bone has

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 22.5** In this case, the bone necrosis is induced by bisphosphonates. Besides necrotic bone showing empty osteocyte lacunes (yellow arrow), infammatory cellular infltrate can be seen in the medullary cavity (black arrows). It is mainly composed of lymphocytes, neutrophil granulocytes, and also plasma cells. Here, signs of the bone remodeling are also visible. The dark line within the bone, the border of the periosteum before necrosis (red arrow) separates necrotic bone in the center from the new-built bone with a lining of active osteoblasts (blue arrow) on the outside

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 22.6** Actinomyces species (green arrow) frequently can be found next to necrotic bone (yellow arrow) in the jaws. Dense clouds of bacteria affecting the bone leading to deep excavations of the necrotic bone. An infammatory infltrate of neutrophil granulocytes and macrophages in fbrin-rich exudate flls the bone marrow (black arrows) as a border which limits bacterial growth

parts with empty osteocytic lacunae next to viable osteocytes so that there are necrotic areas of the bone that harbor parts of the viable bone. Infammatory infltrates are seen in nearly all cases consisting of granulocytes and lymphocytes. The obliteration of mainly the segmental arteries is not existent in every case [28]. The periosteum is usually viable [5].

#### **22.4.1.8 Symptoms**

The classical symptoms are the visible necrotic bone and pain in case of an additional infection of the bone so that the symptoms are very unspecifc.

#### **22.4.1.9 Complications**

The typical complications are the progress of the initial small necrosis so that big parts of the bone might be affected by the osteonecrosis. Since the bone is no longer covered with soft tissue, an additive infection can cause typical symptoms and leads to a shift to a different stage of the osteonecrosis. Major complications are the loss of the integrity of the bone and extraoral fstulas or abscesses.

The quality of life might essentially get affected in patients with medication-related osteonecrosis of the jaws [29].

#### **22.4.1.10 Diagnosis**

The diagnosis is primarily a clinical one if all criteria are fulflled (see defnition). Unfortunately, there is no sensitive radiological tool that shows neither the exact location of the osteonecrosis nor the extent of the necrosis [30]. Once there is a destruction of the bone due to the infection, changes can be seen in the radiologic pictures. But these changes are not specifc for the changes (Figs. 22.7 and 22.8a, b). There is evidence that the potential osteonecrosis can be detected at a very early stage via scintigraphs [31].

#### **22.4.1.11 Diferential Diagnosis**

Regarding the clinical picture, osteomyelitis and osteoradionecrosis are the other typical potential diagnoses. In addition, malignant diseases should be ruled out, especially the ones why the bisphosphonates were given in the frst place, e.g., breast cancer or prostate cancer.

#### **22.4.1.12 Therapy**

The osteonecroses should be treated since the lack of treatment usually ends in the progression with more extended areas of necrotic bone and a potential switch in the stage of the osteonecrosis.

There are several approaches in the therapy of the bisphosphonate-associated osteonecrosis of the jaws. Smaller osteonecroses can be treated conservatively or with a moderate surgical intervention. Perioperative antibiotic treatment should be initiated. After the debridement or resection of the necrotic bone, a plastic coverage of the bone should be performed.

**Fig. 22.7** This is the same patient as seen in picture 4. There are nearly no changes visible that indicate the existence of osteonecrosis. A very typical change that can be seen is the thickened and sclerotic lamina dura in the mandible and the honeycomb pattern of the bone due to the sclerotic trabeculae of the bone

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 22.8** Two slices from a cone beam CT from a patient with a malignant primary disease and bisphosphonate intake. (**a**) Axial slice from a patient with osteonecrosis of the left and the right mandible. On the right-hand side, a thickening of the cortical bone can be observed and sclerosis of the cancellous bone. On the left-hand side, the periosteal reaction is visible. (**b**) Coronal slice with a periapical translucency of the molar on the right-hand side as a potential trigger of the osteonecrosis that reached the level of the alveolar nerve canal. On the vestibular side of the left mandible the periosteal reaction can be seen

Extended or multiple osteonecrotic areas should be resected. This might include an inpatient setting with the postoperative use of a nasogastric tube and antibiotic iv treatment [32].

#### **22.4.1.13 Prognosis**

The recurrence rate of the osteonecrosis depends on the mode of therapy and is the lowest for surgical interventions

#### and the highest for purely conservative treatments. In the latter case, complete closure of the mucosal membrane cannot always be achieved [32].

#### **22.4.1.14 Prevention**

It should be differed between preventive measures before initiating a bisphosphonate therapy and measures during or after the course of bisphosphonate therapy. Since the bisphosphonate-associated osteonecrosis of the jaws is usually triggered by an oral wound, potential dental foci should be eliminated before the start of bisphosphonate therapy [32].

If surgery needs to be performed in patients with bisphosphonate therapy, anti-microbiological prophylaxis should be performed [32].

#### **22.4.2 Osteonecrosis of the Jaws Due to Other Medications but Bisphosphonates**

There are other medications that can cause osteonecrosis of the jaws. The defnition is the same compared to the osteonecrosis due to bisphosphonates.

#### **22.4.2.1 Denosumab**

The most frequent osteonecroses can be observed in patients with denosumab that is administered in the same patients that receive bisphosphonates. The defnition, etiology, classifcation, symptoms, complications, diagnoses, differential diagnoses, therapy, prognosis, and prevention are the same or similar to the ones of the bisphosphonate-associated osteonecrosis of the jaws.

The pathogenesis might be different since denosumab only affects the RANK/RANKL/OPG mechanism that is predominant in the communication between osteoblasts and osteoclasts. Therefore, an impact on the soft tissues including the vessels seems unlikely so that the likewise reduced bone remodeling seems to be the major component in the development of the denosumab-associated osteonecrosis of the jaws.

#### **22.4.2.2 Sunitinib**

Sunitinib is an inhibitor of a tyrosine kinase and therefore has a less specifc mode of action. It is given in patients with gastrointestinal cancers, renal cell carcinoma, and pancreatic neuroendocrine tumors [33]. A side effect in the use of sunitinib is the development of osteonecroses of the jaws [34].

#### **22.4.2.3 Imatinib**

Imatinib is another tyrosine kinase inhibitor. Osteonecrosis in imatinib-only use has been described [35].

#### **22.4.2.4 Bevazicumab**

Bevazicumab is a vascular endothelial growth factor- (VEGF-) inhibitor and is used in several oncologic treatment concepts, e.g., breast cancer, colorectal cancer, and lung cancer. Several cases of osteonecroses of the jaws have been described [36, 37].

#### **22.4.2.5 Ziv-afibercept**

Ziv-afibercept is a recombinant vascular endothelial growth factor- (VEGF-) receptor. Several cases of the development of osteonecroses of the jaws have been described in patients that did not receive any of the other typical medications causing osteonecrosis [38]. In the pathogenesis, the antiangiogenic factor might be the reason for the development of the osteonecrosis.

#### **22.4.2.6 Everolimus**

Everolimus is a mammalian Target of Rapamycin (mTOR) inhibitor. It is used in several oncologic diseases and was associated with the development of osteonecroses in the jaws [39].

#### **22.4.2.7 Corticosteroids**

There is evidence that the use of corticosteroids increases the risk of osteonecrosis development of the jaws [40]. The femoral head osteonecrosis has been described in patients with long-term corticosteroid use [41].

It should be stated that the use of several of these agents in combination might further increase the risk of osteonecrosis development.

#### **22.4.2.8 Crystal Meth**

Next to therapeutically used agents, some drugs are responsible for the development of osteonecroses. Crystal Meth is the crystalline form of methamphetamine hydrochloride. It functions as a sympathomimetic and has a very high potential for abuse and dependency. One side effect is the meth mouth with serious tooth and damage to the oral cavity including the development of osteonecroses [42]. The exact mechanism of osteonecrosis development is unclear. Methamphetamine causes the release of noradrenaline which increases the blood pressure by the increase of the peripheral blood vessel resistance.

#### **References**


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**Part IX**

**Maxillary Sinus and the Oral Surgeon**

Kandasamy Ganesan and Neelam Rathod

#### **23.1 Introduction**

Sinusitis, also known as rhinosinusitis with the association of rhinitis, is a common presentation within the primary care setting, due to the effect it can have on individuals' quality of life. It is defned as the infammation of the mucosal lining in at least one of the paranasal sinuses with an acute presentation lasting for less than 12 weeks and chronic extending to durations greater than this. The maxillary sinus is the largest of four paranasal sinuses and, with its close relationship to the underlying dentition, it is often susceptible to infammatory processes. This chapter explores the anatomy, physiology of the maxillary sinus, the aetiology, assessment and management of maxillary sinusitis.

#### **23.2 Anatomy of Maxillary Sinus**

The maxillary sinus is the largest of the paranasal sinuses and develops during day 65–75 of gestation, with a volume of approximately 1 cm3 at birth. Up untill an average age of 12, pneumatisation of the maxillary sinus continues as the space occupied by tooth germs is freed through their eruption [1]. In the latter stages of development, it pneumatises inferiorly, guided by the eruption pathway of the permanent dentition.

The main function of the maxillary sinus is involved in the humidifcation and warming of inspired air as well as prevention of microorganism ingress through mucociliary action. In addition to this, the paranasal sinus contributes to voice reso-

Department of Oral and Maxillofacial Surgery, Southend University Hospitals NHS Trust, Southend-on-Sea, UK

University of Leeds, Leeds, UK e-mail: mailme@kandyganesan.com

N. Rathod Department of OMFS, Southend University Hospital NHS Trust, Southend-on-Sea, UK e-mail: n.rathod@nhs.net

nance. A possible evolutionary function may also be as a 'crumple zone' during trauma, thus protecting the brain (Fig. 23.1).

In an adult, the maxillary sinus takes the form of a quadrangle pyramidal shape, with the base adjacent to the nasal cavity and the peak extending towards the zygomatic process, and a volume in the region of 15 cm3 . The roof of the sinus is formed of the orbital foor in the centre of which runs the infraorbital neurovascular bundle. The anterior wall of the maxillary sinus is the weakest of the walls, with the thinnest section superior to the canine resulting in the canine fossa. It is also perforated by the infraorbital nerve that supplies the maxillary sinus, along with the greater palatine nerve. The posterior wall of the sinus lies in front of and shelters the internal maxillary artery, sphenopalatine artery, Vidian canal and the greater palatine nerve. The inferior wall is the most varying in shape, with invaginations corresponding to the alveolar bone of the maxilla; the anatomical root structures of maxillary molars and the hard palate. The bone separating the dental roots can be varying

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 23.1** Schematic diagram of the maxillary sinus with representation of the geometric shape of the cavity

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_23

**23**

**Maxillary Sinusitis**

K. Ganesan (\*)

in its quantity; from complete absence to thicknesses of up to 12 mm [2]. This close proximity is a contributing factor towards the likelihood of dental iatrogenic and infammatory pathology presenting in the maxillary sinus. The medial wall that is parallel to the nasal cavity communicates with it through the natural sinus ostium at the postero-superior aspect of sinus. This ostium opens in to a triangular space of approximately 15 mm2 diameter formed by the uncinate process medially, the lamina papyracea laterally and the ethmoidal bulla posteriorly before

©Association of Oral and Maxillofacial Surgeons of India

the nasal cavity and the

**Fig. 23.2** Schematic diagram showing a coronal cross section of the maxillary sinus and the osteomeatal complex

communicating with the nasal cavity through a semilunar hiatus in the middle meatus. This is an area of common drainage from the maxillary, anterior ethmoidal and frontal sinuses. Some individuals may exhibit anterior/posterior fontanelles; bony dehiscences inferior to this, covered with mucosa. These can act as accessory ostia, points of drainage when the main osteomeatal complex is blocked or there is a change in sinus pressure. An osteomeatal complex (OMC) is an important functional unit and is also a key area for the pathogenesis of chronic rhinosinusitis. It consists of multiple bony structures, air spaces and ostia. The bony structures include the middle turbinate, uncinate process of the ethmoid and bulla of the ethmoid. Air spaces are formed by the frontal recess, infundibulum of the ethmoid and the middle meatus. Ostia consists of anterior ethmoid, maxillary and frontal sinuses. The classic OMC as mentioned above has been described as the anterior osteomeatal unit. The sphenoethmoidal recess and the superior meatus are referred to as the posterior meatal unit (Fig. 23.2).

Maxillry sinus septa, present in approximately 28.4% of cases [3], are thin projections of cortical bone that divide the sinus into more than one compartment either in the transverse, sagittal or horizontal plane, usually in the region of the frst or second molar.

Smaller air-flled compartments in the periphery of the maxillary sinus can include Haler cells and Concha bullosa. Haller cells are air cavities encompassed in the ethmoidal capsule and are located below the inferomedial aspect of the orbital foor, and lateral to the ethmoidal cells. These can be present in a range of sizes as well as unilaterally or bilaterally. Concha bullosa is another variant air-flled cavity pneumatised in to the middle turbinate. These particular anatomical (Fig. 23.3) varia-

**Fig. 23.4** Schematic diagram of the secretary and clearance of the mucous via the mucociliary cells

©Association of Oral and Maxillofacial Surgeons of India

tions have the potential to infuence the dimensions of the osteomeatal complex, increasing the likelihood of sinus disease [4] .

#### **23.3 Maxillary Sinus Physiology**

At a histological level, the maxillary sinus consists of ciliated columnar cells, basal cells and goblet cells and thus forming respiratory epithelium architecture. Unlike the rest of the respiratory pathway, the sinuses have fewer ciliated and goblet cells; friable epithelium and fewer seromucous cells, making them prone to microorganism ingress and related pathology.

The clearance of secretions from the sinuses is through a combination of ciliary and mucous action. The mucous secreted by the goblet cells consists of 96% water, with the rest consisting of glycoproteins, immunoglobulins, histamines, lactoferrin, prostaglandins and lysozymes [5]. It functions to trap foreign body and defend against bacterial ingress. This is combined with the ciliary action that promotes a spiral action of movement of the mucous through active transport from the base of the sinus towards the natural ostium in the supero-posterior aspect of the medial sinus wall and thus working against the forces of gravity.

Normal fora within the maxillary sinus is usually a combination of sterile aerobic and anaerobic organisms including bacteria organised in a complex bioflm within the sinus mucus layer. These usually include mainly aerobic B-hemolytic streptococci, staphylococci and *haemophilus spp*. The anaerobic organisms, that are fewer in quantity, include peptostreptococcus, *fusobacterium sp* and bacteroides. Whether these organisms are present in normal physiology or transiently is poorly understood. Host specifc and non-specifc defence against these bacterial species is also part of normal physiology with the sinus mucosa producing secretion including antimicrobial peptides, proteins, neutrophils, macrophages coupled with the mucociliary transport towards the ostium (Fig. 23.4).

#### **23.4 Sinusitis Pathophysiology**

Due to the narrow size of the ostium opening, occlusion and related pathology of the maxillary sinus space are very likely possibilities. Obstruction of the sinus ostium can either be primary to the sinusitis process or secondary infammation originating from elsewhere in the sinus.

With obstruction of the natural ostium, there is reduced oxygenation and gas exchange within the maxillary sinus, alongside reduced mucociliary action and mucous stasis. In the most common acute form of sinusitis, viral upper respiratory tract infections result in signifcant nasal congestion that results in maxillary sinus blockage and stasis. Anatomical differences such as large middle turbinates, deviated nasal septums or concha bullosa can increase the likelihood of ostium occlusion. Polyps, in particular those originating from the ethmoid, may also obstruct the maxillary sinus opening (Table 23.1).

Any form of obstruction and subsequent stasis in the maxillary sinus produce a favourable environment for the fourishing of an anaerobic environment, encouraging the formation of purulent secretions. In addition to this, changes in the sinus pressure, coupled with local mucosal infammation, contribute to the symptoms of pain and pressure in the region [6]. The initial lower sinus pressure is caused by the

consumption of the fnite oxygen within the blocked and confned maxillary sinus cavity. This is followed by a transient increase in pressure where there is a greater production of carbon dioxide and sinus secretion.

Chronic rhinosinusitis has features of long-term infammation, rather than primary infection, of the nasal passages and paranasal sinuses with an unknown underlying cause. It is likely to be part of a cycle involving infammation, infection and subsequent obstruction of the ostium [7]. Without the presence of polyps, chronic sinusitis may be multi-factorial in nature, with one or several predisposing factors as outlined below.

Nasal polyps are oedematous masses of the mucosal membrane found in the nasal passages and paranasal sinuses. Histologically, they show squamous epithelial proliferation, a thickened basement membrane, absence of neurosensory flaments and infammatory cell infltrate with high numbers of oesinophils [8]. The pathogenesis in the formation of polyps and its contribution towards chronic rhinosinusitis is poorly understood. One in vivo study involving rabbits with stimulated maxillary sinusitis observed the formation of infammatory-type polyps in subjects with purulent infection and granulation based polyps in both purulent and nonpurulent infections. In both infective processes, epithelial damage to the mucosal lining appeared to be a signifcant factor in the initiation of polyp formation [9]. Other evidence shows that high levels of interleukin 5, 13 and histamines in the polypoid tissue may also have a contributing role [10]. The general consensus of studies shows a high level of infammatory mediators in the initiation and presence of nasal polyps, suggesting chronic infammation to be a key factor.

#### **23.4.1 Microorganisms of Sinusitis**

The polymicrobial nature of maxillary sinusitis has been well documented. The initial aerobic bacterial infective organisms often include *Streptococcus pneumoniae*, Haemophilus infuenzae and Moraxella catarrhalis in acute sinusitis [11]. Chronic sinusitis has found to harbour the aforementioned organisms in addition to Prevotella species, Fusobacterium species and anaerobic streptococci [12]. More recent studies have cultured *Staphylococcus aureus*, in particular methicillin resistant-type from sinus mucosal samples [13].

#### **23.5 Predisposing Factors**

#### **23.5.1 Anatomical Variation**

Any variation deemed to alter the volume or the size of the maxillary ostium may contribute to an increase risk of sinusitis. This includes [14]:


#### **23.5.2 Atopy (Allergy)**

The distinct relationship between the allergy and infammation remains unclear. Current hypothesis predicts that with the ventilation passage in continuum with the nasal mucosa, infammation along the rest of the airway can affect the nasal passages, thus causing narrowing of the ostium. This is supported by the high incidence of chronic rhinosinusitis with allergies driven by IgE mediators.

#### **23.5.3 Asthma**

The association between chronic sinusitis, mainly with nasal polyps, and asthma has been well documented. Several studies have shown radiographic sinus mucosal abnormalities in individuals with asthma, in particular with those suffering from severe steroid-dependent asthma [15]. Similar studies show a trend in the severity of sinusitis correlating to the severity of asthma experienced, supporting the theory of infammation of a unifed mucosal airway concept of the disease process. The association between asthma and sinusitis is further indicated with studies showing individuals reporting improvement in their asthma symptoms subsequent to medical and/or surgical treatment of their sinusitis [16].

#### **23.5.4 Aspirin**

Aspirin/NSAID hypersensitivity has been found to have an association with a persistent form of chronic sinusitis, usually with the presence of nasal polyps. Along with severe asthma, this disease process has been named the 'Aspirintriad'. The mechanism of pathogenicity is thought to be linked to cyclooxygenase inhibition and inhibition of arachnoid acid metabolism rather than an underlying immunological process. The presence of hyperplastic sinus mucosa contributes to a high level of recurrence in nasal polyps subsequent to sinus surgery for removal [14].

#### **23.5.5 Environmental**

Several environmental factors have been associated with an increased incidence of sinusitis with changes in air quality acting as suggestive stimulants. Greater prevalence has been identifed in patients exposed to chemical air pollutants including pharmaceutical products, photocopying ink byproducts, smoke and dampness [14, 17].

#### **23.5.6 Ciliary Impairment**

This may be present in the form of reduced cilia or ciliary cells, causing impairment of mucociliary fow and thus creating environments favourable for bacterial or viral sinusitis.

#### **23.5.7 Smoking**

Smoking is likely to diminish the presence of normal microbiological fora in the nasal and paranasal spaces, allowing for the growth of pathogenic microorganisms and thus eliciting a hypersensitivity reaction in the sinonasal mucosa [14].

#### **23.5.8 Gastro-Oesophageal Refux**

It has been suggested that infammation may be elicited when the oro- and nasopharynx comes in contact with gastric acids during refux and subsequently contributing to sinusitis [18].

#### **23.5.9 Odontogenic Maxillary Sinusitis**

As part of the examination process, this should be evaluated at the early stages and could prevent prolonged periods of investigations and symptomatic management (Fig. 23.5). Approximately 15–24% of unilateral maxillary sinusitis cases are believed to be of odontogenic origin [19], with some studies indicating this fgure to be as high as 40% [20]. In a metaanalysis of 15 observational review studies consisting 770 cases, the frst molars were found to be the most common tooth to be causative for odontogenic sinusitis (22.51%), followed by third molars (17.21%), second molars (3.97%), premolars (5.96%) and lastly canines (0.66%). The etiological contribution to the sinusitis was found most commonly to be from iatrogenic factors (55.97%), periodontal disease (40.38%) and odontogenic cysts (6.66%) [21]. Figure 23.6 outlines the distribution of the iatrogenic processes leading to sinusitis [21].

The disruption in maxillary sinus foor, from whichever odontogenic source, causes localised infammation that remains persistent in that area or spreads along the sinomucosal surface with subsequent obstruction of the sinus ostium. Bacterial colonisation have been shown to consist of both aerobic and anaerobic species in 75% of cases, with the other 25% predominantly anaerobic in nature. *Staphylococcus aureus* and streptococcus pneumonia were the predominant aerobic bacteria isolated. When looking at the anaerobic bacteria distribution, Peptococcus and Prevotella species dominated and haemophilus and Moraxella species were absent in cases of odontogenic maxillary sinusitis [20].

#### K. Ganesan and N. Rathod

#### **23.6 Classifcation of Sinusitis**

Sinusitis is defned as an infammation of the paranasal sinus mucosal lining; however, it rarely presents in isolation and is usually coupled with the infammation of the nasal mucosa, thus being termed as rhinosinusitis. The cardinal features, of which two are required for a suggestive diagnosis of a rhinosinusitis, are outlined in the 2012 European position paper by the International Rhinology Society (Table 23.2). The condition is broadly classifed based upon the chronicity of the condition as well as whether there is presence of polyps.

#### **23.6.1 Acute Rhinosinusitis**

Acute rhinosinusitis (ARS) is defned as persistent sinusitis that resolves within a 12-week period. It is a common presentation within the populations globally, with prevalence rates between 6 and 15% [14].

#### **23.6.2 Chronic Rhinosinusitis**

Chronic rhinosinusitis is defned by the persistence of sinusitis symptoms for greater than 12 weeks, with no resolution after initial sinusitis treatment. It is further subdivided into whether there is a clinical and radiographic presentation of nasal polyps.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 23.5** (**a**) A coronal section of a CT of maxillary sinus showing extensive left-sided maxillary sinusitis. A periapical radiolucency on the upper left frst molar with a breach in the cystic area to allow the pus to enter the sinus and causing the sinusitis. (**b**) A sagittal section same image showing the extent of the sinusitis. A periapical radiolucency is noticeable in relation to mesiobuccal root of upper left frst molar

©Association of Oral and Maxillofacial Surgeons of India



#### **23.6.3 Fungal Rhinosinusitis**

This subtype of chronic rhinosinusitis involves the infammation of the maxillary sinusitis that is attributed to a fungal pathogen and can be classifed into acute fungal rhinosinusitis, fungus balls or fulminant invasive fungal rhinosinusitis.

Acute fungal rhinosinusitis (AFRS), as described by Bent and Kuhn, is characterised by fve properties [22]:


The predicted pathogenesis of AFRS is believed to be an allergic, immediate hypersensitivity reaction to an inhaled fungal organism resulting in a chronic infammatory response in a predisposed individual, usually with asthma. The most common isolated fungal species include Bipolaris, Curvularia, Aspergillus, and Drechslera species.

Fungal balls are non-invasive, dense collections of fungal debris within the maxillary sinus. Found in mostly immunocompromised and elderly individuals, they are formed commonly of aspergillus, in response to prolonged exposure to the fungi through inhalation of airborne spores or oral antral communication.

Acute invasive fungal sinusitis is a rapidly infltrating growth of the fungi with a high risk of morbidity and mortality. Immunocompromised individuals that are predisposed to this include those with:


Initial clinical presentation involves an acute onset of facial/head pain, fever, epistaxis and, in severe cases, of bony erosion with extrasinus infltration and possible mental status change. Urgent surgical management and post-operative antifungal therapy is required.

#### **23.7 Clinical Diagnosis**

Diagnosis of sinusitis is primarily through clinical history and examination with the possible adjuncts of imaging studies and/or laboratory testing. The signs and symptoms of sinusitis can be categorised in to major and minor. Major features include infraorbital and maxillary facial pain, pressure sensation, congestion/obstruction sensation, purulent rhinorrhoea, hyposmia and fever [23]. Minor features are present in some of the individuals with suspected sinusitis and include headache, fatigue, dental pain, halitosis, cough and ear pain/fullness.

The acute form of rhinosinusitis is indicated usually when a patient has recently suffered with the symptoms of an upper respiratory tract infection that is viral in nature. After an initial 7–10 day phase of viral infection with gradual recovery, patients give history of worsening symptoms. Evaluation of nasal discharges show secretions that were once clear at the at the initial stages of the viral infection that become yellow, green or grey in nature at the latter aspect of the biphasic disease process. Unilateral disease process provides greater indication towards sinusitis. Palpation over the infraorbital sinus region would elicit tenderness due to the pressure build-up from stasis and infammation of the sinus cavity.

Patients with suspected chronic rhinosinusitis may present with symptoms of acute rhinosinusitis but to a milder degree, with the absence of a predisposing upper respiratory tract infection including fever. The presenting complaint may often be of the lack of effectiveness in acute medical management techniques [24]. Regardless of whether the causative factor in the chronicity of their sinusitis is from the presence of nasal polyps or not, patients will often present with facial pain or pressure, anterior or posterior nasal discharge and slight fatigue. Those that suffer from chronic sinusitis without the presence of polyps may also experience anosmia or hyposmia. Thus, the ambiguity in presentation makes the diagnosis of chronic sinusitis with clinical history and examination alone challenging, but nonetheless provide a vital role in their diagnosis and long-term management.

Endonasal examination in the form of anterior rhinoscopy may also be performed with headlighting and a speculum; alternatively with the large speculum of an otoscope. It can play a supportive role in visualising infamed nasal mucosa, presence and quality of nasal discharge and the turbinates with an indication of nasal polyps or anatomical variation that may not have been suspected previously.

Nasal endoscopy provides an enhanced technique for direct visualisation of the nasal passage. Abnormalities in the nasal passage can be seen including the middle, superior turbinates and the osteomeatal mucociliary drainage passage. Where acute rhinosinusitis is diagnosed mainly through clinical history and simple examination, this method is more relevant for incidences of chronic rhinosinusitis. Nasal endoscopy can be used at 3, 6, 9 and 12 monthly intervals in chronic disease process to assess the degree of infammation, discharge and size of nasal polyps.

Intraoral assessment should include assessment of both soft and hard tissues. The dentition requires close evaluation to rule out primary aetiology which can account for 5–10% of acute rhinosinusitis cases [25]. Detailed assessment for extensive dental caries, periapical and/or periodontal infections for teeth distal to the canine is required. Where multiple teeth are unilaterally tender to percussion with a lack of correlation to dental pathology clinically or radiographically, sinusitis not of dental cause is a probable diagnosis. This sensation may also be elicited with facial or head movements. This is due to the close neural relationship between the maxillary sinus and upper molars. Pain or pressure sensation is also elicited from palpation in the most superior aspect of the maxillary buccal sulcus. In some cases, posterior discharge in to the nasopharynx that is either characteristically **Table 23.3** Differential diagnosis for maxillary sinusitis, NICE guidelines 2018 [26]


clear or coloured in nature can be visualised during intraoral assessment.

Recurring episodes of acute rhinosinusitis (more than three episodes a year) requires wider consideration of the primary causative factor. Peters et al. has attributed recurrent acute rhinosinusitis to various reasons such as immunodefciency, cystic fbrosis, ciliary dysfunction and anatomic abnormalities [16] (Table 23.3).

Severe episodes of acute rhinosinusitis originating from the maxillary sinuses are a rare presentation. Complications can arise with the involvement of the ethmoidal and frontal sinuses that are in close proximity to vital structures including the anterior cranial cavity and the orbits with associated venous drainage systems [27].

As per Ah- See et al. [28], certain features of sinusitis that require urgent intervention are:


#### **23.8 Clinical Imaging**

Clinical imaging is a useful adjunct to the diagnosis of sinusitis. It can provide confrmatory and characteristic information to guide management of the condition.

Plain radiography is an accessible and cost-effective means of visualising the maxillary sinus. An orthopantomogram (OPG), though focusing on the dentition, maxilla and mandible, also includes a signifcant proportion of the maxillary sinuses and provides an opportunity to identify the presence of pathological features. Indication of sinusitis would be from the presence of unilateral or bilateral generalised diffuse radiopacity within the maxillary sinus. Causative disease process can also be visualised including the proximity of periapical pathology from the maxillary dentition, periodontal disease, cystic lesions of dental origin, foreign body presence, sinonasal mucocele or polyps. The signifcant level of artefact from overlying structures however limits the usefulness of this imaging modality. Where dental disease is a suspected contributing factor, dental periapical radiographs can be considered for a targeted and enhanced dental evaluation. Consequently, a dental cause for sinusitis can be challenging to diagnose, in particular in cases of chronic sinusitis.

The occipitomental view, also known as the 'Water's view, can additionally offer visualisation of the entire sinus as well as other paranasal sinuses, with fuid collection and mucosal thickening evident at varying angles. Care must be taken to differentiate between a benign mucosal cyst and a fuid level. A diagram showing the difference in the appearances between the two is shown in Fig. 23.7.

Despite the effciency with which these images can be taken, one should consider whether the overall information gained for sinusitis diagnosis justifes the exposure to radiation. Plain imaging does not offer a comprehensive view of the maxillary sinus ostium, the occlusion of which will often be the causation of subsequent sinusitis. Apart from suggestion in the presence or absence of disease process, it does not offer information on the severity of the condition. With signifcant overlap, diagnosis of sinus masses can also be diffcult.

Computer tomography (CT) (Fig. 23.8) offers the threedimensional visualisation of the sinuses and can be confrmatory in the presence or absence of sinus disease. These should be considered only where a patient's symptoms are vague or frst-line medical management has thus far failed to offer signifcant relief of symptoms. Contrast medium is not required as they do not offer additional value towards diagnosis or management. It should also be noted that where CT scans of sinuses are taken, maxillary teeth should also be included to assess for their involvement in the disease process.

With appropriate manipulation of imaging sections, the location and severity of sinus disease can be gauged. Mucosal thickening is distinctly evident on CT scans, being more pronounced in cases of sinusitis with polyps. Further diagnostic information is available on the sinus content including air– fuid levels. The patency of the sinus discharge tract can be assessed with detailed view of the osteomeatal complex on coronal sections thus allowing for surgical planning. The presence or absence of nasal masses can be confrmed in CT cases but can be used to differentiate between sinus polyps, cysts or tumours. Generalised thickening or sclerosis of the maxillary sinus walls may be indicative of chronic sinusitis whereby early infective processes cause demineralisation of the sinus wall and prolonged reactive host responses that result in sclerotic bone deposition. Where sclerosis is more localised in the maxillary sinus wall, there may be indication towards enquiry of previous sinus surgery.

Cone beam computer tomography (CBCT) can provide enhanced information on the pathological processes contrib**Fig. 23.7** Diagram showing the difference between the fuid level and the mucosal cyst/polyp

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 23.8** A coronal view of a CT scan showing thickened mucosal lining of the both maxillary sinus with a fuid level on the left maxillary sinus

uting towards sinusitis, with slices as fne as 0.4 mm as well as offering a lower radiation dose exposure, in the region of 10%, in comparison to a fne slice CT scan (Fig. 23.9).

This is more relevant for cases of maxillary sinusitis of dental origin in which pathological processes can be tracked from the tooth to the sinus structure.

MRI scans offer an imaging modality that allows some enhanced interpretation in the appearance of the soft tissue within the sinus. This is not relevant in the majority of uncomplicated maxillary sinusitis presentations. The use of MRI is limited to cases where there is opacifcation of the maxillary sinus with no obvious obstruction, osseous abnormality or odontogenic pathology. It allows the differentiation between mucosal infammation, complete fuid collection or a tumour within the maxillary sinus as well as its origin.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 23.9** CBCT of the sinuses showing upper second molar with a breach in the periodontal ligament space and periapical area opening into the maxillary sinus causing sinusitis—a classic odontogenic sinusitis

#### **23.9 Treatment**

#### **23.9.1 Conservative Management**

In acute sinusitis cases, with a primary virus and secondary bacterial infection, the aim of treatment focuses around relieving of symptoms including pain, nasal congestion and discharge during the 2–3 week period that it will take to resolve. Antibiotics in the early stages are not recommended. Advice can be offered in the management of systemic virus infection including physical rest, adequate analgesia and increased fuid intake.

The pain sensation from the maxillary sinus region is attributed to pressure changes caused by occlusion of the ostia and thus, treatment to promote unblocking will inherently contribute towards pain reduction. During this process, analgesia in the form of paracetamol and ibuprofen can be utilised for management of pain.

Nasal saline and decongestants have been shown in some literature to be an effective means of opening the ostia and ecouraging ventilation.

Nasal saline mists and irrigations can offer a breakdown of nasal blockages, dilution of irritants and allergens, reduction of postnasal drainage and overall more effective mucociliary clearance [29]. Lavage/irrigation of the nasal passage can be performed using small quantities of salt or bicarbonate dissolved in warm water. These can be administered by inhaling small volumes of the self-made formulation in cupped hands through each nostril until nasal ventilation feels clearer. Alternative over-the-counter devices such as squeeze-bottles and syringes can be used. Humidifed air and steam inhalation can also be utilised as a means of nasal secretory blockage breakdown. These irrigative techniques can offer supportive relief to other symptomatic management methods but are not deemed effective as monotherapy [30].

Where there is indication of chronic sinusitis, potential risk factors should be identifed and addressed, including avoidance of triggers that may exacerbate allergies and asthmatic fare-ups. Where applicable, patients should be encouraged to stop smoking or being exposed to passive smoke.

#### **23.9.2 Medical Management**

Where acute sinusitis symptoms last for longer than 10 days, medical treatment modalities can be offered.

#### **23.9.2.1 Nasal Decongestants**

Topical nasal decongestants can be offered as a means of improving sinonasal ventilation through reducing mucosal secretion, nasal congestion and thus improved patency of the osteomeatal complex. Topical formulations can include phenylephrine (0.25%), oxymetazoline (0.5%) and xylometazoline [31]. These should be limited to use twice a day for up to 3 days. These formulations have a sympathomimetic effect causing vasoconstriction with subsequent reduced fuid secretion and mucosal infammation. Longterm use of these agents can produce a rebound effect with the absence of sustained vasoconstriction.

#### **23.9.2.2 Topical Nasal Glucocorticosteroids**

Topical intranasal glucocorticosteroids may be considered in the management of prolonged acute rhinosinusitis or chronic rhinosinusitis as an adjunctive or monotherapy prior to the consideration of antibiotic prescription [32]. These can be utilised for up to 3 months in adult patients depending on the formulation used and especially where allergy is deemed a signifcant risk factor. Common formulations utilised include budesonide, ciclesonide, futicasone furoate, futicasone propionate, mometasone furoate and triamcinolone acetonide. These have been deemed an effective means of clearing nasal and sinus air passages in several studies when used in a retroclined, head tilt action to encourage exposure towards the middle meatus.

#### **23.9.2.3 Systemic Glucocorticosteroids**

The use of systemic glucocorticosteroids has been reserved for refractory cases of chronic rhinosinusitis, in particular those with allergy [2], as well as initial treatment for patients with suspected allergic fungal rhinosinusitis. It can provide symptomatic relief through improving ventilation through the sinuses, reducing the size of polyps and thus restoring some sense of smell. Current British guidelines suggest prednisolone 0.5 mgk/kg for 5–10 days as well as the adjunct therapy with betamethasone nasal drops [33], taking relevant consideration of those already on steroids for other conditions.

#### **23.9.2.4 Antimicrobial Therapy**

There is limited evidence to support the use of antibiotics in the short term for acute rhinosinusitis. A Cochrane review of 10 trials based in the primary care environment found that irrespective of treatment modality with or without antibiotics, 71% of patients' symptoms of uncomplicated acute sinusitis had resolved by the 2-week mark [34]. Where symptoms of sinusitis arise, the microbes of dominance usually include aerobic streptococcus pneumonia, haemophilus infuenza and Moraxella catarrhalis. Antibiotic therapy should be reserved for cases of acute exacerbations of rhinosinusitis where symptoms haven't resolved after 7–10 days or for severe cases involving signs of systemic spread including fever and severe unilateral facial pain. Though the evidence is limited, some literature supports the use of amoxicillin for 7–14 days. This is mostly effective; however, approximately 20–30% of haemophilus infuenza strains have been found to be resistant to amoxicillin due to the production of lactamase [35]. During persistent periods of acute sinusitis or during exacerbations of chronic sinusitis, there is a shift towards a mixture of anaerobic and aerobic pathogenesis. The Infectious Diseases Society of America recommends amoxicillin clavulanate as the frst choice of antibiotic for 5–7 days [36], with clindamycin, doxycycline, levofoxacin or moxifoxacin for those with an allergy to penicillin. This can be used in combination with topical glucocorticosteroids to attain more effcient symptom relief [32]. In cases of chronic sinusitis, use of low-dose macrolides has shown some effectiveness [14]. In all cases, where viable, the choice of antibiotic should be guided by microbiological culture growth, attained from discharges from the middle meatus or surgically guided sample collection.

#### **23.9.3 Surgery**

Surgical intervention is routinely carried out by Ear, Nose and Throat speciality and is usually indicated in the failed medical management of chronic sinusitis or as the frst treatment for acute fungal rhinosinusitis. The aim of surgery is to attain normal function through restoration of ventilation and allowing physiological mucociliary drainage of the sinuses. This can be through opening and widening of the osteomeatal complex, removing foreign body and polypoid tissue, clearing the sinus of infected mucin, removal of chronically infamed mucosal and bony tissue whilst throughout preserving as much of the virgin, healthy mucous membrane in the sinus as possible.

Extra-oral or intra-oral approaches can be taken. The classically used internal access is the Caldwell-Luc approach. George W Caldwell frst published this technique in the New York Medical Journal in 1893, where he utilised the canine fossa approach to gain access to the sinus and perform intranasal drainage, signifcantly improving surgical outcomes. Henry Luc, a french surgeon, further adapted this method in 1897 for surgical treatment of chronic sinusitis where performed antrstomy in the middle meatus whilst Caldwell had performed an inferior meatal antrostomy.

#### **23.9.3.1 Surgical Method: Caldwell-Luc Approach**

Advanced imaging like CT or CBCT should be used for the procedure. Particular awareness is required for the presences of any septae that may interfere with the Caldwell-Luc access in to the sinus. In addition, assessment is required of the availability of a window on the anterior wall of maxillary sinus, with short maxillary sinus height creating challenges in this approach.

This procedure can be done either under a general or a local anaesthetic with sedation support; though complete painrelief and anaesthesia with the latter option is diffcult to achieve (Fig. 23.10). Once adequate anaesthesia has been achieved, the upper lip is retracted an incision is made 2–3 mm above the mucogingival junction, parallel to the occlusal surface of the teeth. A full-thickness mucoperiosteal fap can be raised with a molt"s periosteal elevator to reveal the underlying bone. Often, bulbosities caused by the root projections of the upper canines and premolars are noticeable and they can be used as anatomical landmarks to avoid damaging the roots of the teeth. The periosteum can be raised elevated all the way to infraorbital foramen and care must be taken not to stretch the infraorbital nerve. Then a bony window can be made with a Rosehead bur 2–3 mm above the root apices of the teeth. On entry in to the sinus, a microbiology swabbing of the sinus content is done for culture and sensitivity. Once the swab has been taken, this is followed by stripping of the sinus lining, espe-

©Association of Oral and Maxillofacial Surgeons of India

#### **Fig. 23.10** A diagram showing the intraoral approach for the Caldwell-Luc technique

cially when treating chronic, persistant sinusitis. The lining can be removed with a microdebrider, Freer's elevator and curettes. Care must be taken not to remove tissue from the roof of the sinus due to the fact infraorbital nerve can be seen through the canal resorbed by maxillary sinusitis.

Any soft tissue curetted from the sinus can be sent for histopathological examination. A 30 or 45 degree endoscope is used to visualise the foor of the sinus which is not feasible with a standard 0 degree FESS. To complete the procedure, an intranasal antrostomy can be done to improve the drainage of the sinus. This procedure can be done by passing a curved haemostat through the nasal aperture to penetrate the lateral nasal wall, 1-1.5cm posterior to the anterior attachment of the inferior nasal turbinate. Care should be taken to avoid injuring the opening of nasolacrimal duct. The projection of the haemostat can be visualised with an endoscope in the sinus simultaneously. Forceps are used to remove the fragments of bone created from the enlargement of the ostium and thus complete the intranasal antrostomy. The intra-oral Caldwell-Luc access is used to provide a fnal saline-wash within the sinus, prior to achieving haemostasis and would closure, often with resorbable sutures.

#### **23.9.3.2 Complications with Caldwell-Luc approach**

Complications associated with this surgical technique include infraorbital nerve parasthesia that is often transient and may last up to 6 months. Similarly there may be numbess of the attached gingivae and associated teeth or even possible devitalisation. If the lacrimal apparatus has been encountered, there may also be the risk of dacryocystitis.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 23.11** (**a** and **b**) Naso endoscopic pictures showing as the scope enters the left nostril. Nasal septum (NS) on the left and Inferior turbinate (IT) on the right and the uncinate process (UP). Further up showing maxillary sinus ostium (SO) and Uncinate process (UP)

#### **23.9.3.3 Surgical Method: Functional Endoscopic Sinus Surgery**

With technology continually advancing, many prospective studies report functional endoscopic sinus surgery (FESS) (Fig. 23.11) to be a safe and effective means of managing chronic sinusitis. For the FESS approach to be an effective surgical method in the management of chronic sinusitis, appropriate patient and surgical instrumentation related factors require consideration. Standard preparation for FESS involves an oral endotracheal tube which can be positioned based on surgeon's convenience to improve the access. Prior to donning surgical scrubs, the neuro-patties soaked in a vasoconstrictor solution may be placed along the foor and middle portion of the nasal cavity such that it is effective at the start of the operation. In addition, all Encoscopic acumen should be ready for the beginning of the procedure. Endoscopic instrumentation includes a 0, 30, and 70 degree angle scope, a powered debrider with a 4 mm straight and a 60 degree cannula, 4 mm long curved suction, various types of punch forceps, curettes and a monopolar suction cautery.

Before the start of the procedure, neuro-patties are removed and 1% lidocaine and 1:100000 adrenaline injected into the septum, middle turbinate and uncinate process for the maxillary sinus-related issues. To survey the width and depth of the nasal cavity and also to establish the boundaries to avoid any complications, a systematic examination of the nasal cavity carried out with a 30 degree scope attached to an endoscopic tower/viewing screen. All the nasal structures should be visualised including posterior nasal choana and the inferior turbinates.

Systematic intranasal survey with the scope is also carried out as a part of the surgical planning to identify any nasal septal spur, septal deviations and turbinate hypertrophy to improve the access and to prevent any complications. Additionally, any polyps can be removed to improve the access. An angled probe is used to refect the uncinate process to visualise hiatus semilunaris and infundibulum. Back fracturing the uncinate process fnally allows visualisation of the maxillary sinus ostium and medial wall of the orbit. A 4 mm trimmer can be used to remove uncinate and part of the middle turbinate to gain access to maxillary sinus ostium. The superior border of the sinus ostium is an important anatomical landmark as it is the junction of the medial wall of the orbit and the lamina papyracea. At this point of dissection, a decision can be taken to do a minimal or extensive dissection process, and this depends on the extent of the disease process. Mostly, a minimal dissection (expansion of the ostium) is all that is necessary.

#### **23.9.3.4 Complications with the FESS Approach**

FESS is an essentially safe procedure in the hands of a trained and experienced surgeon; however there are a wide range of risks associated with this procedure due to the proximity of anatomical structures such as the orbits and their content, major arterial and venous structures and the base of the skull. Severe complications can include orbital content penetration that may lead to fat herniation, enopthalmous and damage to extraocular muscles; penetration in to the skull base can result in cerebrospinal fuid leakage and carotid artery dissection may cause a stroke or even death. Orbital content penetration leading to fat herniation, enophthalmos and damage to extraocular muscles. Crusting, septal perforation, mild bleeding, nasal obstruction, anosmia, minimal fat herniation from orbital wall perforation and crusting of the nasal mucosa are examples of what are believed to be minor complications.

Sinus surgery should be supported with medical management post-operatively to prevent further infammation developing, particularly in the case of polyp removals that may re-establish without maintenance therapy.

#### **23.10 Conclusion**

Sinusitis can be a debilitating condition for patients whether acute or chronic. With close proximity to the dentition, symptoms of dental pain can result in presentation to the maxillofacial and dental professional. A succinct clinical history and examination is vital in attaining an accurate diagnosis. Though management is guided by diagnosis, management should commence with symptom relief.

**Acknowledgements** We would like to acknowledge Mr. Martyn Barnes and SurgTec for the endoscopic pictures attached to this chapter. More endoscopic images and videos can be accessed from www.surgtech.net website.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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## **OroAntral Communications and OroAntral Fistula**

Suvy Manuel

*Routine exodontia is a common procedure performed by the general dental practitioner and the oral surgeon alike. Most of the maxillary premolar/molar extractions heal uneventfully but some may cause inadvertent opening into the maxillary sinus, manifesting as immediate oro antral communications (OAC) or delayed oro antral fstulae. The common reasons being diffculty encountered in the extractions intra operatively due to myriad reasons or the OAC may be due to a pre existing pathology in the peri apical region or within the sinus lining. Whatever the reason be , its paramount that the surgeon identifes the problem and approach it in a sequential manner to avoid long term consequences and to attain a perfect closure. The timing of the closure is crucial which is dependent upon the sinus health and the socket condition. This may be complicated by a missing root tip which is lying in the sinus. This chapter aims to walk the reader through these events in a logical fashion, so that they can take appropriate decisions and use the correct surgical technique which will ensure a successful closure of the defect*.

#### **24.1 Introduction**

Maxillary sinus is an anatomical area, which is intimately associated with the feld of oral and maxillofacial surgery. Many of the procedures done violate the integrity of the maxillary sinus, as in orthognathic surgeries, or when the sinus is involved per se as part of midface trauma or in odontogenic pathologies that infringe upon the sinus.

The relevance of the sinus in day-to-day minor dentoalveolar surgical procedures is that the sinus foor is in very close approximation with the roots of the maxillary posterior teeth, especially the molars [1].

Eberhardt, in 1992, did a CT study to evaluate the distance between maxillary sinus foor and the apices of the maxillary pre-molar/molar teeth. The buccal frst premolar showed the largest value of 6.18 mm (SD 1.60 mm). It is quite disturbing to know that the mesiobuccal root of maxillary second molar is only 0.83 mm (SD 0.49 mm) away from the maxillary sinus foor, as per this study results. Readers are advised to refer the table in reference [1] to have a better picture of this relevant CT study.

This intimate relation with the root of maxillary molars causes many a time inadvertent communication between the sinus and oral cavity causing acute OroAntral communication (OAC). If the OAC is unrecognized or not dealt with primarily, either it may undergo spontaneous healing if the circumstances are favourable or it may progress into a fullfedged OroAntral fstula (OAF), which will need secondary intervention for closure.

This section of the book deals with OAC and OAF caused during exodontia and minor dentoalveolar surgical procedures, cyst enucleation and small-sized tumour excision.

Communications caused due to excision of moderate to large pathologies, post-oncosurgery defects, major maxillofacial trauma, gunshot/missile injuries, osteoradionecrosis and developmental and congenital deformities usually may require locoregional/free fap transfers and/or prosthetic rehabilitations. Such communications are dealt with elsewhere in this book.

This section is limited to closure of OAF caused after exodontia; however, many surgical techniques used for OAF closure do overlap with surgical closure techniques of oronasal and palatal fstulas. Those techniques are dealt with in relevant sections of the book.

This chapter also deals with managing and retrieving root/root tips, which are inadvertently displaced into the sinus (Root in sinus).

Most of the surgical procedures aimed at correction of OAC/OAF are doomed to fail if the underlying sinus is not

**24**

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 491

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_24

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_24) contains supplementary material, which is available to authorized users.

S. Manuel (\*)

Department of Oral and Maxillofacial Surgery, Ananthapuri Hospitals and Research Institute, Trivandrum, Kerala, India

Kerala Institute of Medical Sciences, Trivandrum, Kerala, India

healthy before the anticipated closure. The "Antral regime procedures" are aimed at ensuring a disease-free sinus before anticipated elective closure of a post-extraction OAF. When patients are referred to oral surgeons for treatment of OAF, depending upon the duration of complaint, the sinus may be in various stages of the disease. It is diffcult to ascertain whether the sinus was diseased primarily at the time of exodontia, accentuating the chance of an OAF formation or whether the sinus had been secondarily infected following the formation of OAF due to direct communication with the oral cavity. Another possibility is that the sinus lining would have been secondarily involved by a periapical pathology and removal of the involved tooth was conducive to the formation of the OAC.

The role of an otorhinolaryngologist cannot be understated, and at times, the closure has to be attempted after consulting with them regarding the sinus health. Their presence may be required during the closure for allied procedures in the sinus like FESS (Functional Endoscopic Sinus Surgery).

#### **24.2 Aetiology of OAC**

The common causes for OAC during dentoalveolar procedures are


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.1** Improper use of dental elevators causing pushing of root tip into maxillary sinus

**Fig. 24.2** Sinus dipping down in a long-standing edentulous area of upper left frst molar (IOPA)

10. Lack of adherence to basic principles of dentoalveolar surgery or overzealous/aggressive attempts to remove or retrieve fractured root tips of maxillary posterior teeth may cause OAC. It is the judgement of the concerned clinician whether to attempt removal of a fractured root tip; if the clinician can remove the root tip via the socket through closed intra-alveolar technique well and good, if not the clinician should be able to remove the tip via transalveolar technique based on sound dentoalveolar surgical principles and should be able to close the OAC if it occurs. If the clinician feels that he is not able to perform the above-mentioned procedure, it may be wise

**Fig. 24.3** (**a**) IOPA of a molar showing periapical lesion, (**b**) Extracted molar with the lesion attached to the root tip, (**c**) Diagrammatic representation of periapical lesion close to sinus foor

©Association of Oral and Maxillofacial Surgeons of India

not to vigorously attempt to remove the root tip. Either he should get expert help or it would be judicious to leave the root tip behind and attempt removal later if required when expert help is available (Fig. 24.4).

11. Teeth, which have aberrant root anatomies, dilacerations, hypercementosis and ankylosis, are all at risk of developing OAC.

#### **24.3 Clinical Features of OAC**

The basic rule to be followed when we suspect an OAC is never to enlarge or aggravate the existing communication. Most of the time OAC goes unrecognized, and it may heal spontaneously if it is less than 3–5 mm in diameter [2]. If a bigger OAC is not recognized and adequate measures are not taken for closure, it may progress to OAF. Unless it is an evident OAC, confrmatory tests are not done in order to prevent enlarging the OAC. Literature also says that sinusitis will ensue if the OAC is not closed within 24–48 h.


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.4** Diagram showing the importance of slow, careful and fne movements to remove root tips with straight probes, fne mosquito forceps or apical fragment ejectors

#### **24.3.1 Radiological Features of OAC**

There may not be radiological evidence of a small OAC on a routine IOPA, unless there is sizeable loss of antral foor or breach in antral foor, which will manifest as a direct communication between the sinus and socket. It is not advisable to insert a probe or radiopaque marker into the socket and take an x-ray as it may enlarge the OAC.

#### **24.3.2 Management of OAC**

The OAC may be managed in the following step wise approach:

1. If you suspect an OAC, it is prudent to inform the patient about the anticipated treatment plan and the sequel.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.5** Note the sinus foor attached to the roots of an upper third molar after extraction, with associated tuberosity fracture. It is a defnite case of OAC, which warrants primary closure if conditions are favourable

Patient has to be aware of the condition as postoperative compliance form of the patient is of paramount importance in order to prevent any dehiscence or clot break down at the OAC closure site. *(See antral regime section.)*

2. Openings less than 3–5 mm in size may be left without any intervention hoping for spontaneous healing, or a primary closure may be attempted depending upon individual case scenarios. If left for spontaneous healing, patients are specifcally instructed to avoid any manoeuvres, which may increase the intra-sinus pressure.

A routine suturing across the socket in maxillary premolar/molar extraction sites may not suffce in suspected cases of OAC, as the buccal and palatal gingivae may not approximate primarily and healing may be secondary in nature. Suturing in such cases just plays a role in supporting the clot. If aiming at primary closure to treat OAC, the buccal and palatal gingivae may be approximated by the following additional measures:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.6** Depicts releasing incision in the palate, to advance the fap in order to achieve primary closure of the socket

Beyond these two steps, any attempt at closing the OAC would mean that the surgeon is using techniques that are common with established techniques of closing an OAF. If primary closure is not obtained by (a) or (b), the next logical step would be to raise a buccal full thickness three-sided (trapezoidal/rectangular/4 cornered) fap and advancing it to the palatal side. At this stage, if adequate relaxation is not present for the fap, the mucoperiosteum may have to be scored and the details of this are given in OAF surgical closure section of this chapter.

If the sinus is healthy, the best chance of closing an OAC is at the time of occurrence and the surgeon may use any of the techniques in his armamentarium, and these decisions are taken on a case-by-case basis.

#### **Clinical Scenario 1**

A simple clinical scenario is given here as food for thought for the young readers (Fig. 24.7).

I believe that there may be different opinions, with few possible ones being


This case was included just to show how perplexing a routine clinical situation could be and to stress on the importance of a solid pre-operative plan before attempting such cases.

#### **24.4 OroAntral Fistula**

Intrusion into the maxillary sinus and establishment of direct communication with the oral cavity are referred to as an oroantral fstula (Fig. 24.8a and b). An oroantral fstula is a pathological condition in which the oral and antral cavities have a permanent communication by means of a fbrous connective tissue fstula coated by epithelium. Once an unrecognized OAC does not heal or there is failure of attempted closure, the condition progresses to an OAF, which means that the epithelization of the communicating tract has occurred. Usually, such cases get referred to the oral surgeon from the general dental practice within 2–3 weeks of the occurrence, when patient notices oronasal regurgitation.

#### **24.4.1 Aetiology of OAF**

The causes for OAF are similar to those of OAC mentioned earlier. Apart from this, if the sinus has pre-existing sinusitis/antral pathology/fungal infections/fungal balls, the **Fig. 24.7** This is the OPG of a 25-year-old man who reported for routine extraction of root stump of upper left frst molar tooth. OPG shows an incidental fnding of a periapical lesion (which is probably a periapical cyst that appears to be very close to the sinus foor or probably pushing the sinus lining up). How would you manage this case?

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.8** (**a**) Note the OAF on upper left frst molar extraction site. The socket edges are well-healed, epithelized and rounded off. (**b**) OPG of the above case showing a defect in the alveolar ridge in the 26 socket region and direct communication of the sinus with the oral cavity

chance of healing of OAC is decreased and may progress to OAF.

Among patients who do not follow the post-extraction instructions or where the clot is defcient/gets dislodged, chances of OAF are increased in susceptible cases. Failed sinus lift procedures, ailing and failing implants and periimplantitis are all potential causes for causing OAF.

#### **24.4.2 Clinical Features**


4. In long-standing untreated cases, there will be clinical and radiological features of chronic sinusitis. The antral lining will undergo thickening/hyperplasia, and eventually, sinus gets obliterated or there may be evidence of sinus polyps.

I have seen a case where the patient was referred with a protruding sinus polyp through the socket of an untreated OAF in a maxillary molar site (Fig. 24.9a and b). In this particular case, a root was displaced into the sinus as well. It was not sure whether this polyp ensued secondary to OAF or whether pre-existing sinus polyp leads tothe OAF.

We should also be aware that antral malignancies may protrude through the unhealed socket of maxillary molars. Most of the times, the surgeon being ignorant of the disease would have extracted the tooth due to mobility caused by the erosion due to the malignant lesion, and a few weeks after, the patient may present, with the lesion protruding through the socket (Fig. 24.10).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.9** (**a**) Clinical picture showing an antral polyp protruding through the sinus. Some clinicians may consider this to be a Post-extraction granuloma possibly of a reactive nature due to the root in the sinus. (**b**) Occlusal X-ray view showing root in the sinus

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.10** A case of extraction of upper right second molar due to mobility by dental surgeon, who was unaware of the cause of mobility being antral malignancy. Couple of weeks after extraction, the lesion was seen protruding through the socket

5. The mucosal edges of the socket will be rounded off, and an evident opening may be seen via the socket into the sinus.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.11** IOPA x-ray showing metal probe entering the sinus via a minute unhealed OAF defect

6. In certain cases, the ridge will clinically look well-healed; however on careful probing, an unhealed tract will be seen, leading to the sinus (Fig. 24.11).

#### **24.4.3 Confrmatory Tests of OAF**


nose with the nostril closed. The wisp will vibrate under the fow of air via the OAF (cotton wisp test/butterfy test).


#### **24.4.4 Treatment Modalities for OAF**

Techniques for OAF closure have evolved over a long period of time and have a robust history. Many techniques have been time tested and well-established, form the mainstay of OAF closure and will be discussed in this section. Literature is replete with various technical modifcations; it is not possible to discuss all these in detail and will be beyond the purview of this chapter. The reader is advised to look into the references if a thorough review of techniques is required [3, 4]. Figure 24.1, in reference [4] (Visscher et al. JOMS 2010), gives an excellent overview of the various treatment modalities for oroantral communications Awang et al. [5] back in 1988 have published an excellent review of techniques, which were established at that time.

Since a plethora of techniques are available, the surgeon has the freedom to choose the technique, which works well in his hands based on the training received and surgical competence. One cardinal rule, which may be followed in OAF closure, is to start with the simplest technique available and reserve the complex technique in case the frst attempt fails. A sequential option may be followed, the patient is to be warned that there are chances of failure and a secondary or tertiary surgery with more complex techniques may be required at times.

At this stage, it is worth remembering a quote which I have come across somewhere: "*Re-operation after past failures at the hands of other surgeons should be approached with due humility*".

The options for treatment can be broadly categorized under the following headings:


The most widely used local faps can be classifed as


The multitude of techniques and variations has made the literature on OAF closure a trife confusing. It is interesting to know that even third molar auto transplantation has been found to be successful in closure of immediate OAC (Kitagawa 2003) [6].

In this chapter, we will only be discussing the time tested and commonly performed buccal/palatal faps with a reasonable amount of success rate. The tongue faps are a second option, but the diffculty is caused to the patient in the postoperative period until the pedicle is divided and the need for patient compliance, diffculties in feeding, mastication; speech and maintenance of oral hygiene should be taken into consideration before performing them.

As there are multitude of variations and modifcations in OAF closure techniques, the author feels that it is wise to present all the relevant modifcations in a sequential order (Box 24.1). If the reader refers to the historical evolution of techniques given in the box format, it is evident that different fap designs have been advised ranging from advancement, sliding, pedicled, rotation, bridge, hinged, transverse buccal, double faps, island faps, bipedicled faps, submucosal connective tissue fap, osteoperiosteal faps, buccinator myomucosal faps, etc. Each technique has been presented with its own indications and advantages. The reader is advised to read individual publications to get details of these techniques if required.

Irrespective of the technique used, the success of the closure warrants that the basic sound principles of mucoperiosteal fap design are used. *The fap should have adequate blood supply, should be handled gently, and should lie in the advanced position without tension*.

#### **24.4.5 Assessment of OAF**

The following factors should be assessed while planning the technique of closure in an OAF.

Size of the communication (Bone defect is always bigger than the visualized soft tissue defect)


#### **24.4.6 Objectives in Treatment of OAF**

When treating an OAF, the surgeon should have the following objectives in mind [7]. (This can be called the 4 E's).


#### **Box 24.1 Historical Evolution of OAF Closure Techniques**


#### **24.5 The Buccal Advancement Flaps**

The names of Moczair, Berger and von Rehrman have been used interchangeably when speaking of buccal faps in the literature. The buccal fap designed by Moczair [9] was a sliding trapezoidal fap, while the ones designed by Berger [11] and Von Rehrman [10] were buccal straight advancement mucoperiosteal faps.

Von Wowern (1982) [47] in a study of 90 patients compared Moczair with Rehrman faps and advocated the former for treating OAF in edentulous patients. Killey and Kay (1967) [48] proved the effcacy of buccal fap in a large series of 250 cases. The buccal fap technique can be satisfactorily employed in the treatment of small and medium-sized communications where there is clear sinus lavage through OAF, and proper antral regime has been maintained 4–5 days prior to the surgery.

The technique of raising a buccal fap is given along with the 2 layer BFP closure technical note box (Box 24.2) and is essentially the same. A few words are needed to elaborate on the buccal fap and periosteal scoring. The buccal fap raised is a full thickness trapezoidal (rectangular/4 sided) mucoperiosteal fap. There are 2 releasing incisions, one anterior and one posterior. The incisions are put in such a way that the fap looks tongue/funnel-shaped and is feasible for advancement palatally without tension. Great care is given to raise it gently without causing any 'button holing'/fenestrations in the fap. The base should be broad enough to have good random blood supply, and fap margins should be incised sharply in order to avoid ragged edges. It is the periosteum that gives tension and may prevent advancement palatally. In order for the fap to lie passively, the periosteum alone is scored gently with a number 12 or 15 blade, horizontally at the level of the base of the buccal fap. This will release the tension and help in advancement. The scoring is a fne procedure, and the surgeon should be aware that, if the scoring goes deep beyond the level of periosteum, the mucosa may be incised which may even jeopardize the viability of the fap by affecting the blood supply emanating from the base (Fig. 24.12).

#### **Box 24.2 Technical Notes of a 2 Layer BFP Closure**


One disadvantage of all buccal advancement procedures is the decrease in the vestibular depth, which may be problematic for prosthetic rehabilitation.

#### **24.5.1 Step-by-Step Technique of Doing Buccal Advancement Flap + Buccal Fat Pad Grafting (BFP)**

The step-by-step procedure for 2 layer closure technique is given in the box format (Box 24.2). The steps of performing a 2 layer closure are similar to the buccal advancement alone, except that the BFP is raised, advanced and sutured primarily to the palatal edge.

The use of the buccal fat pad (BFP) as a grafting source in the closure of intra-oral defects has gained popularity in the last quarter of the twentieth century. Its use as a pedicle graft for oral reconstruction was frst reported by Egyedi in 1977 [26]. Studies have proved through a series of cases that the use of buccal pad fat in the closure of oroantral communications has signifcantly reduced the failure rate of the treatment. The closure of OAF with single-layered buccal mucoperiosteal advancement faps (Berger/Reherman) has been well documented in the literature. Without much change in the surgical steps, adding a second layer of BFP will enhance the success rate of closure.

The buccal fat pad (BFP) as an anatomic element was frst mentioned by Heister in 1732 and was described by Bichat in 1802 [49]. The BFP (Bichat ball) is an anatomically rounded and biconvex structure that is of great importance in the facial contour. It is an adipose tissue surrounded by a thin capsule

Body

Buccal Extension

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.13** Anatomical representation of the buccal fat pad

and located inside both masticatory spaces in the oro-maxillofacial region (Fig. 24.13). The BFP has a central body with four extensions: pterygopalatine, temporal, pterygoid and buccal. The central body and buccal extension account for approximately 50% of the BFP and are the most clinically signifcant portions. The BFP has a 10 mL volume, a thickness of 6 mm and an approximate weight of 9.3 g. The BFP is surrounded by a thin fbrous capsule. Blood supply is provided by the vestibular and deep branches of the maxillary artery, the transverse facial branches of the superfcial temporal artery and branches of the facial artery. The rich blood supply may explain the high success rate. It also may be one reason for the quick epithelialization of the fat. The buccal fat pad is a mass of specialized fatty tissue called as syssarcosis, a fat that enhances muscular motion. It is distinct from the subcutaneous fat and shows marked similarity to the orbital fat. It can easily cover small to medium sized defects of about 4 cm in diameter. When properly dissected and mobilized, the BFP provides 7 × 4 × 3 cm of a pedicled graft. (Box 24.3).

#### **24.5.2 Clinical Pictures Demonstrating 2 Layer Closure Technique with BFP** (Fig. 24.14a, b, c, d and e) [50]

Figure 24.14a, b, c, d and e: Reprinted with permission from springer nature customer service centre GmbH: springer publisher: Journal of maxillofacial and oral surgery: The versatility in the use of Buccal Fat Pad in the closure of oroantral fstulas. Suvy Manuel et al. [COPYRIGHT 4524640093264] (2015).

#### **Box 24.3 Advantages of Buccal Fat Pad**


#### **24.6 Palatal Rotational Flap (Ashley's Flap)**

Among palatal faps, there are 2 main types: The palatal straight advancement fap (Fig. 24.15) and the palatal rotational fap (Fig. 24.16).

However, the palatal rotational fap proposed by Ashley in 1939 [12] has stood the test of time. It is a pedicled fap, posteriorly based on the greater palatine vessel. A tongueshaped full thickness mucoperiosteal fap is raised on the side of the OAF. The OAF site is freshened, and the fstula is excised as a preparation to receiving the fap. The fap is rotated and sutured on to the OAF site. In order to avoid kinking at the site of rotation near the palatal margin of the socket, a V-shaped area may be excised (Kruger's [13] modifcation). The raw site is packed with dressing to allow secondary healing. This is a thick, bulky and vascular fap, which is quite reliable and serves often as a second line of defence when the buccal advancement fap fails. Different authors have given various names for this fap-like rotational, advancement and transposition.

Other types of palatal faps mentioned or published in the literature are the palatal island faps (Henderson 1974 [21]), palatal hinged/inverted/reverse fap (Rintala 1971 [18]) and sub-mucous connective tissue fap (Ito & Hara 1980 [28]). Palatal faps are also used as part of double fap techniques as proposed by Zeimba in 1972 [19] and Quayle in 1981 [29].

#### **24.7 Importance of Timing of Closure of OAF**

The health and status of the socket edges and margins play an important role in deciding the success of the closure, irrespective of the surgical technique used. An OAF, which is well-rounded margins and does not show any evidence of oedema/infammation, is a good recipient area for the closure. Oral surgeons may often get referred cases with history of diffcult extraction of maxillary molars/attempted removal of fractures root tips/cases with established OAC and/or with missing root tips. Often, the socket may show evidence of traumatic extraction with ragged margins, tissue loss, irregular bony edges, congestion, tenderness and oedema. Such sites are not favoured for an OAC/OAF closure, and surgeons should not be tempted to attempt a closure. The chances of failure of the closure are high due to unhealthy mucosal condition and its prudent to wait for a couple of weeks for good healing of the wound edges and then consider closure. It may be argued that the sinus health may deteriorate during this waiting period, and all these are decisions to be taken by the surgeon on their individual merit (Fig. 24.17a and b).

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.15** Diagrammatic representation of a palatal straight advancement fap

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.16** Diagrammatic representation of a palatal rotational fap

#### **24.7.1 Role of Health of Sinus and Antral Regime**

Depending upon the duration of OAF, the sinus may be in various stages of disease. In acute OAC, unless there is preexisting disease, the closure may be attempted with a fair chance of success. In untreated cases of OAF, patients may have acute episodes of sinusitis or progress into a chronic stage manifesting thickened antral lining and fuid/exudates/ pus collection in sinus or antral polyps. In cases of acute nature, the sinusitis has to be under control before closure (Fig. 24.18).

**Fig. 24.14** (**a**) Oroantral fstula seen at the maxillary right frst molar extraction site (**b**) Buccal fat pad being teased out from the buccal vestibule. (**c**) The buccal fat pad being advanced and sutured to the palatal margin. (**d**) The buccal mucoperiosteal fap sutured to the palatal margin and covering the buccal fat pad. (**e**) Excellent healing of the closure site (2 month post-operative view) [50]

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.17** (**a**) Clinical picture of a referred case in a 30-year-old male, who had a traumatic extraction of upper right frst molar 1 week back. One complete root has been pushed into the sinus (see OPG, Fig. 24.17b). Note the traumatized, congested, oedematous and ragged

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.18** A coronal CT scan, showing periapical widening/lesion in a maxillary left molar, which is close to the sinus foor and reactive sinus lining thickening in that region. Possible OAC resulting from this extraction may have a decreased chance of success after immediate closure

#### **24.7.2 The Antral Regime**

Antral regime is usually helpful, which is usually started about 5–7 days before the anticipated closure. It includes.


sutured wound edges/tissue loss and slough in the palatal tissue. He is not a candidate for closure immediately. It is preferable to wait until complete healing and schedule the procedure electively. (**b**) OPG of the above case showing the root in the sinus cavity


The antral regime may be continued for a few days (3–7 days) after the closure as well to ensure a trouble-free healing. After closure, the patient is advised to have certain restrictions in the initial healing phase, in order to avoid break down of the closure, i.e.


However, there are thoughts that the splint may irritate or traumatize the sutured edges on the alveolar ridge and be a deterrent for the healing.

#### **24.7.3 Antral Lavage**

At times, the antral lavage is done daily or on alternate days along with the antral regime to clear the exudate from the

**Fig. 24.19** Diagrammatic representation of antral lavage via the existing OAF

sinus. The presence of exudate/pus can be seen as a 'fuid level' in a paranasal sinus X-ray, or there may be generalized opacifcation of the involved sinus in the X-ray. The closure is attempted, only when the surgeon feels that the antral washouts are clear, and the sinus is reasonably healthy to receive the closure.

ENT books describe different methods of antral lavage, either via a Caldwell Luc opening or via the nasal meatus depending upon the case. However, from an oral surgical perspective for most cases, antral lavage may be done via the existing OAF (Fig. 24.19). 10–20 ml of saline is fushed through the OAF via a syringe, and patient is seated at a forward position with head bent down. The washout will fow out through the nasal cavity or via the OAF, and the washout is collected in a tray positioned before the patient. In the initial days of lavage, the washout will have a cloudy/opaque appearance, and after few days, we should expect the washout to be clear.

#### **24.8 Caldwell Luc Procedure**

This procedure was developed independently by two surgeons, George Caldwell in New York (1893) and Henry Luc in Paris (1897) (Box 24.4).

#### **Box 24.4 Technical Note: Caldwell Luc Procedure in Oral Surgery Context**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.20** Clinical picture showing a Caldwell Luc procedure via extended crevicular fap for removal of a root in sinus. Note the defect made in the anterior maxilla wall

It involves making an opening in the anterior wall of sinus in the canine fossa region, to get good access to the sinus. The procedure is done either via a sublabial incision or by extended crevicular incisons (Fig. 24.20). In the context of OAF, this approach has relevance when combined along with the closure of OAF. The approach may be used to retrieve root tip or to surgically treat chronic sinusitis as in polyps. In combined cases, the extended crevicular fap with adequate releasing incisions may be used to remove root tip and may be used as a buccal advancement fap with or without buccal fat pad graft for the closure of OAF.

The indications for Caldwell Luc procedure are given below:


#### **24.9 OAF with Chronic Sinusitis**

Such cases are more diffcult to manage and will need a combined oral surgery/ENT approach. There may be severe antral lining hyperplasia and lack of natural drainage by blockage of the ostium or antral polyps. The line of management has to be decided on an individual basis. Occasionally, the sinus problem may have to be addressed before attempting a closure, which may require two surgeries. Sometimes, the oral surgeon may be in for a surprise during OAF closures to see fungal balls in the sinus. The reasons for c/c sinusitis should be evaluated and addressed accordingly.

The second option is to attempt closure along with the treatment of chronic sinusitis. In such cases, a formal Caldwell Luc opening may be made to remove the unhealthy lining. If that is the case, the buccal faps are modifed as per requirement to get a tension-free closure at the OAF site. In situations where FESS is used, oral surgeon can visualize the sinus and see the OAF from the nasal/antral side. The use of FESS gives a two pronged approach, i.e. the unhealthy lining from the antral side of the OAF can be removed and closure performed. This means that in OAF with c/c sinusitis, a general anaesthesia will be necessary, unlike uncomplicated OAF cases where most of the established techniques may be done under local anaesthesia if required.

Adams (2015) [51] has reported on the success of using combined FESS and BFP closure. The sequence followed by Adams included pre-operative computed tomography, antibiotic therapy, exploration and removal of sinus pathologic tissues, rotation of a pedicled fat pad graft into the oral opening, repair and closure of oral mucosa, exploration of involved sinuses with excision of sinus and nasal tissues necessary for establishment of osteomeatal drainage and follow-up.

Cases of fulminant pansinusitis have been encountered arising from long-standing untreated OAF. This involves the contralateral side, and such cases need a comprehensive joint approach with the allied specialities, before embarking upon closing the OAF.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.21** Coronal slice CT scan, showing hyperplasia of sinus lining, especially on the right side, where the OAF can be Appreciated

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.22** Coronal CT scan of a 50-year-old male, who had normal extraction of upper left second molar, which was followed by break down of clot and resulted in OAF. He later developed infection with pus discharge from socket. CT scan shows the fully opacifed left sinus. Under GA (joint case with ENT surgeon), a 2 layer BFP closure was done, accompanied by FESS and Caldwell Luc approach via extended mucoperiosteal fap. Intraoperatively, the sinus was flled with fungal balls, which could have been the cause for the formation of OAF

Figures 24.21, 24.22 and 24.23 show coronal CT slices of different case scenarios where OAF was accompanied by chronic sinusitis.

In Video 24.1, the video contributing Surgeon has managed an OAF associated with chronic sinusitis, by a combination of Caldwell-Luc procedure, Nasal antrostomy, and layered closure by buccal advancement fap. Layered closure has been achieved by suturing of sub mucosa and mucosa of the advanced buccal fap.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.23** Coronal CT view showing pan sinusitis in 58-year-old male, who developed an OAF in the anterolateral wall of maxilla from a previous failed surgery, probably for a cyst enucleation in the maxilla (previous records not available)

#### **24.10 Nasal Antrostomy**

The ostium of maxillary sinus opens into middle meatus, which is at a higher level than the sinus foor (Fig. 24.24). In normal healthy sinus, this is not a problem as the normal ciliated respiratory epithelium will help in the drainage. Briefy saying, nasal antrostomy is a procedure where an opening is made in the inferior meatus, either from the nasal or sinus side to facilitate drainage of sinus in a dependent manner. Nasal antrostomy is an adjuvant procedure, which can be done along with cyst enucleations of the sinus or in selected cases of OAF closure. The need for nasal antrostomy has decreased now with changing philosophies, the advent of FESS and the importance given to the osteomeatal complex. Recent studies (Huang YC [52] 2012) have also proved the decreased need for inferior meatal antrostomy following sinus surgeries.

For elaborate details of Caldwell Luc and nasal antrostomy procedures, readers are advised to refer the concerned speciality books.

#### **24.11 Root in Sinus**

In situations where a fragment of a root or a full root or roots is missing during extraction of maxillary premolars or molars, the surgeon will have to take certain decisions and some questions should fash through his or her mind.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.24** Diagrammatic coronal section of sinus demonstrating the sinus drainage


While attempting removal of a root tip, if it suddenly disappears, make sure that the tip is not there in the following places.


If the root tip is assumed to be pushed upwards into the sinus cavity, the tip may lodge in the following areas:

(a) A fenestration would have happened in the apical labial/ palatal alveolar bone, and the tip would be lodged between the labial/palatal alveolar bone and the mucoperiosteum.


X-rays in two different planes (IOPA/OPG/Occlusal) will be helpful to give an idea about the root tip position especially when it is inside the sinus. When the root tip is retaining its lamina dura on an IOPA x-ray, it may be assumed that it is still lying within the bone and not have entered the sinus cavity. Paranasal sinus view will confrm that the root is in the sinus and CBCT also may be helpful in localization.

In situation (a), Transalveolar approach will help in removing the root tip.

In situations (c) and (d), the following methods are suggested in the literature and the resulting OAC is closed primarily or at a later stage depending upon the surgeons' choice.


#### **24.11.1 Policy of Leaving Root Tip In Situ**

It is important to say a few words on this topic at this juncture, even though there may be difference of opinion and contentions on the points given below. These can be applied to all root tips being left behind. If the clinician

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.25** In this case, the surgeon is attempting to remove the root in sinus, which has been dislodged superiorly during the extraction, by enlarging the socket and an extended mucoperiosteal fap has been raised. The sinus can be visualized via the socket. This technique is usually not recommended as the resulting OAC will be of considerable size; however, in this case, the OAC was closed by a 2 layer BFP technique

feels that removing a fractured root tip of an upper premolar/molar is beyond his or her level of competence or there is a possibility of causing OAC, which he or she cannot deal primarily, the root tip may be left behind in the following situations;


The patient should be well-informed about this situation and should be informed that the tip may be removed later if they wish so. Adequate documentation in the form of x-rays and clinical notes is mandatory, in order to follow up the case and to avoid any future medico-legal issues.

#### **Clinical Scenario 2**

An interesting clinical Scenario for the beneft of young clinicians.

A 40-year-old female had routine extraction of root stumps of upper left frst molar. A pre-operative IOPA was not taken. After extraction, to the surprise of the dental surgeon, there was pus discharge through the socket (See Fig. 24.26a and b)

The probabilities are that either there was a pre-existing sinusitis, which was unrecognized, or the root stumps caused the odontogenic infection to spread into the sinus.

#### **How will you Manage this Case?**

There may be different opinions, but the following sequence may be followed in this particular case, which is given as clinical pearl section below.

#### **Clinical Pearls (Management of Case in Fig. 24.26a and b)**


#### **Clinical Scenario 3** (Fig. 24.27a, b, c and d)

Another interesting clinical scenario, which I came across in a maxillofacial trauma case recently, is given as follows:

A 36-year-old male sustained RTA and facial fractures as seen in Fig. 24.27a and b. Tooth numbers 15 and 16 (upper right frst pre-molar and molar) were avulsed with comminution of labial cortical plate and the alveolar process creating an oroantral communication (Fig. 24.27c). You can appreciate the bubbling of mucus at the OAC site. CT showed bilateral haemosinus, fracture maxilla and mandible, The right posterior alveolar segment containing 17,18 (upper right second molar and third molar) was mobile and extruded due to a posterior right parasagittal fracture of the maxilla.

It was a challenging case to plan and execute.

The upper sub-labial incision, given for the maxillary fracture exposure, was curved down distal to 14 (upper right frst pre-molar) and continued as a full thickness crevicular mucoperiosteal fap. The distal release was not given, for fear of jeopardizing the vascularity of the posterior alveolar segment. The BFP was mobilized in the conventional way (Fig. 24.27d), and a good two-layered primary closure was attained after reduction and fxation of the fractures. The posterior alveolar segment had to be fxed to the main segment via transosseous wiring. This segment was extruded, and to achieve healing and occlusion, post-operative IMF was given. This particular patient was on Ryles Tube feeding for few days, mainly due to other injuries and tracheostomy, which would have helped in the good healing of the OAC closure.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.26** (**a**) Surprise fnding of pus from socket after extraction of upper left frst molar root stumps, (**b**) PNS view taken after extraction shows fuid level in the sinus, probably due to pre-existing sinusitis

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 24.27** (**a**, **b**, **c** and **d**) OAC following maxillofacial trauma (see the text for details)

#### **24.12 Conclusion**

The clinician should be cautious of not deliberately causing an OAC while performing exodontia and dentoalveolar procedures in maxillary posterior region. An OAC should be ruled out in suspected cases, and if it occurred, necessary steps should be taken to ensure a closure primarily if possible. Even as this chapter is going to the publishers, clinicians are exploring the possibilities of new techniques, of which the fapless closure techniques of acute OAC seem to be quite promising. Closing OAC with PRF membrane/collagen composite [53, 54] offers easier, less traumatic methods to close OAC, which may even obviate the need for special surgical expertise. Materials like acellular dermal/

bone matrix are also being used recently [55] However, only time will prove the obduracy of these path breaking methods.

Visscher [56] in a retrospective study of 308 oroantral closures found that about 10% needed re-operation, and patients with maxillary sinusitis had 15 times higher risk of developing a recurrence.

Dealing with OAF cases is interesting in the sense that it involves assessing the health of sinus and choosing and performing the most suitable surgical technique, most of which are fne surgeries. It is indeed rewarding to see a symptom-free patient with a well-healed OAF closure site.

#### **References**


repair. Hua Xi Kou Qiang Yi Xue Za Zhi 2018 Dec 1;36(6):633– 637. https://doi.org/10.7518/hxkq.2018.06.010. Chinese.

56. Visscher SH, van Roon MR, Sluiter WJ, van Minnen B, Bos RR. Retrospective study on the treatment outcome of surgical closure of oroantral communications. J Oral Maxillofac Surg. 2011 Dec;69(12):2956–61.

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**Part X**

**Nerve Injuries and Neuralgias of Oral and Maxillofacial Region**

## **Trigeminal Nerve Injuries**

#### Tara Renton

There are infnite opportunities in dentistry to damage the trigeminal nerve. Nerve damage from surgery can cause chronic post-surgical pain; however, this is limited in dentistry as a result of Local anaesthetic (LA) infltration injections but more commonly associated with injuries to the nerve trunks of division two and three caused by implants, endodontics and third molar surgery (or other high-risk extractions). Fortunately, painful post-traumatic trigeminal neuropathy (PPTTN) is rare in dentistry compared to other common general surgical procedures where 20–45% of patients experience persistent pain after surgical limb amputation, thoracotomy and breast surgery. This chapter highlights the prevention (using risk assessment, optimal surgical techniques, early post-surgical follow-up protocols and other strategies) and optimal management of trigeminal nerve injuries.

Trigeminal nerve injury (TNI) associated with chronic pain is the most problematic consequence of dental surgical procedures with major medico-legal implications [1]. The incidence of lingual nerve injury has remained static in the UK over the last 30 years, but is increasing in the US, as is the incidence of inferior alveolar nerve injury in the UK, with the latter being due to implant surgery and endodontic therapy [2]. Third molar surgery-related inferior alveolar nerve (IAN) neuropathy or inferior alveolar block injections are usually temporary but can persist and become permanent (by defnition at 3 months). There are rare reports of resolution of implant and other cause-related IAN neuropathies at over 4 years, [3] but these are not similar reports of other peripheral sensory nerve injuries [4–7]. In dentistry, frequently, a treat delay is 3–6 months [5], which is inappropriate when compared to other peripheral sensory nerve injuries where immediate repair and exploration are recommended. We now understand that known or suspected, restorative (endo and implant)-induced nerve injuries require intervention ideally immediately, within 30 h or within 3 months, dependent upon the mechanism of injury, to optimize resolution from injury and prevent the permanent central and peripheral changes within the nervous system [6, 7].

Paraesthesia is often inappropriately used in the dental literature to mean neuropathy. However, paraesthesia is only a descriptive term, meaning altered sensation and not a diagnosis. When sensory nerves are injured, a neuropathy (malfunction) may arise, and this may be painful or non-painful.

The trigeminal nerve has the largest representation in the sensory cortex, refecting the disproportionate sensory input from the orofacial region. It protects vital structures that underpin our very survival, providing sensory supply to the eyes, airway, brain, mouth and ears. It is no 'wonder' that when the threat or actual pain arises in the trigeminal nerve area that the patient is neurophysiologically wired to 'run for the hills' from the dental chair. Latrogenic (caused by surgery or medicine) trigeminal nerve injuries (TNIs) result in 70% pain in patients seen seeking treatment on our clinic [7]. The ongoing or evoked pain results in interference with eating, speaking, sleeping, applying makeup, shaving, kissing, tooth brushing and drinking; just about every social interaction, we take for granted. As a result, these injuries have a signifcant negative effect on the patient's self-image, quality of life and psychology [7].

With the increasing age of the patient, the time elapsed since the injury and the proximity of the injury to the cell body (the more proximal lesions have a worse prognosis) will dictate the persistence of any peripheral sensory nerve injury.

There are many non-surgical causes for trigeminal neuropathy, and these must be borne in mind if the patient presents with an unclear onset of motor or sensory neuropathy [8].

Sensory nerve injuries caused by implant and endodontic treatments are mainly permanent. Only LA nerve injuries have a 75% likelihood of recovery and lingual access third molar surgery and have 90% potential for recovery [9].

T. Renton (\*)

**25**

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 515

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_25

Oral Surgery, Kings College London, London, UK e-mail: Tara.renton@kcl.ac.uk

Referral of patients with these nerve injuries before 4 months [2] is too late for optimal resolution or management as inferior alveolar nerve injuries often require an immediate implant or endo-treated tooth removal within 24–30 h. We now understand that after 3 months, permanent central and peripheral changes occur within the nervous system subsequent to injury, which are unlikely to respond to surgical intervention [10].

Nerve damage is likely to result from a combination of poor risk assessment, poor technique, lack of recognition and the acute management of intra-operative and postoperative signs of neuropathy. Risk assessment involves the patient selection, pre-operative planning, both clinical and radiographic, appropriate selection of implant site and type (width and length) and suitable treatment protocol and follow-up.

It is important that the clinician is familiar with the nerve injury risk factors, specifc for each of the types of invasive procedures. For example, in the case of protrusion through the IDC and resultant direct IAN mechanical injury by implant drill, a "sudden give" or an "electric shock" type feeling, even with local anaesthesia working, is reported by most of the patients seen in our clinic with post-traumatic neuropathy. This should result in the clinician stopping surgery, not reaching for another LA block injection and reassessing their surgical position with regard to the injured nerve.

The problem with implant-related nerve injuries is that they are entirely avoidable as this is elective surgery, thus negligent, and likely to be permanent and painful for the patient [11]. In addition, persistent nerve injuries cannot be resolved. Surgical intervention for hypoaesthetic nerve injuries does not return the patient to normality [10], and surgery for patients with pain and hyperaesthesia is not appropriate as the pain is not abated and patients are faced with longterm anti-epileptics or anti-depressants for chronic pain [11].

When assessing patients with surgically induced nerve injuries, we recommend a more holistic approach in assessing patients with nerve injury [8]. The defnition ICHD 3 (International Craniofacial pain and Headache Disorders) of painful post-traumatic trigeminal neuropathy (PPTTN) includes development of neuropathy within 3 months of injury with sensory neuropathy and pain. The author believes that the neuropathy develops immediately after trauma, unless related to endodontic procedure where there may be a 2–3 days delay in neuropathy development. Features of iatrogenic trigeminal nerve injury worthy of assessment include

• Focal sensory neuropathy (mostly present). There is almost always an area of abnormal sensation (neuropathy with the exception in Trigeminal neuralgia which is NOT post-traumatic), and the maximum reported pain is associated with the area of sensory defcit (i.e. suffering from a mixture of pain, numbness and altered sensation). This is an important diagnostic feature for sensory nerve neuropathy.


The following sections address the prevention and management of trigeminal nerve injuries related to


#### **25.1 Local Anaesthetic-related Nerve Injuries**

Local block injection-related nerve injury is an acknowledged complication in relation to surgery [13]. Dentistry is the only speciality that still trains clinicians to aim for nerves rather than avoiding neural contact (often using ultrasound), which likely explains the continued prevalence of LA-related nerve injuries in dentistry. All other block injections are undertaken using ultrasound in order to avoid nerve injury. One report highlights that the prevalence of IDB-related nerve injuries in UK General dental practise is 1:14,000 blocks, or 1:56 K IDB patients experience permanent lingual or inferior alveolar nerve injury of which this 25% of nerve injuries are permanent [9]. It is estimated that every practising dentist will experience causing 4–6 temporary nerve injuries and one permanent nerve injury related to IDBs during their working life based upon current practice.

Nerve injury may be due to many causes including physical (needle, compression due to epineural or perineural haemorrhage), ischaemic or chemical (haemorrhage or LA contents). The site of the injury may also vary and combine peri-, epi- and intra-neural trauma causing subsequent haemorrhage, infammation and scarring, resulting in demyelination (loss of nerve lining) [14]. Only 1.3–8.6% of patients get an 'electric shock' type sensation on application of an IAN block and 57% of patients suffer from prolonged neuropathy having not experienced the discomfort on injection, and thus, this is not a specifc sign [15]. Routine practice in Germany includes warning patients of potential nerve injury in relation to dental block injections. Risk factors for persistent local anaesthesia nerve injuries are summarized in Table 25.1.

The lingual nerve (LN) is at increased risk of permanent injury compared to the IAN during local anaesthesia, possibly related to the reduced number of fascicles in the LN compared to the IAN [16].

Higher concentration agents are more neurotoxic and, therefore, more likely to cause persistent inferior dental block (IDB)-induced nerve injury [17–22]. Irrefutably, Schwann cell death is related to increased concentration and

#### **Table 25.1** Risk factors for persistent neuropathy related to IDBs

In order to minimize complications related to dental LA, you need to consider modifying the following risks:


time exposure to LA [22]. Articaine is provided in 4% concentration and Lidocaine in 2% solution in most countries. A recent prospective randomized study reports that there is no beneft or using 4% Articaine IDBs compared to 2% Lidocaine [23], which is substantiated by other evidence [24–27]. Thus, logically why would anyone use a higher concentration agent for an IDB when there is no increased effcacy and higher risk of nerve injury? [28]

Intra-operatively, all clinicians should document unusual patient pain reactions occurring during injections or surgery (such as sharp pain or an electrical shock-like sensation), as neuralgia during injections is associated with increased persistence of nerve injury [15]. Thus, it is important that the clinician uses an appropriate LA method to prevent proximity of the injection/surgical instruments to the IDC, for example, infltration anaesthesia for implant surgery.

#### **25.1.1 Avoiding Block Anaesthesia by Using Infltration Dentistry**

Daublander et al. reported that in a 2014 [23] survey of German dental LA practise, 74% were using infltration dentistry routinely and rarely giving IDBs (personal communication). Improved patient comfort is reported by patients with preference for having full lingual sensation and shorter duration LA anaesthesia after dental treatment.

There is further evidence to support the notion of infltration dentistry can be successful in many aspects of dentistry

• *Maxillary infltration anaesthesia*

Studies report that 4% Articaine to be more effective than 2% lidocaine for lateral incisors but not molars [25], differing from other reports [23, 25]. A recent randomized controlled trial reported a statistically signifcant difference advocating the use of 4% Articaine in place of 2% lidocaine for buccal infltration in patients experiencing irreversible pulpitis in maxillary posterior teeth [24, 26]. This has been superceded by a metanalysis that reports there is no advantage in using 4% Articaine for maxillary infltration anaesthesia and that 2% Lidocaine is suffce for dental interventions.

• *Pulpal anaesthesia in the anterior mandible compared to inferior dental block (IDBs) [*25*].*

Meechan provides evidence supporting the signifcantly increased rates of pulpal anaesthesia using infltration anaesthesia when compared to IDB anaesthesia particularly for premolar and incisor teeth (Fig. 25.1).

• *Pulpitic mandibular molars in adults [*23*,* 25*,* 29*,* 30*].* A recent systematic review reports that Articaine is 3.4 times more effective for pulpitic mandibular molars when compared to lidocaine, but there is no difference between Articaine and Lidocaine maxillary infltrations or IDBs [31].

**Fig. 25.1** Summary of infltration methods to minimize nerve injury

• *for exodontia in adults and children [*32*].*

Paedodontic extractions do not require IDBs as the bone is very porous and susceptible to absorption of infltrative anaesthesia.


Intra-ligamental anaesthesia for extractions and avoiding IDBs is also gaining population [34].

**Key Facts for Prevention of local anaesthetic nerve injuries.**

Thus, prevention of LA nerve injuries is possible and some simple steps may minimize LA-related nerve injuries:


### **25.2 Management of LA Nerve Injuries**

Evidence base remains limited for managing dental LA-related nerve injuries; we only know that 25% are permanent and that there is no 'magic bullet' to fx them. A sit and wait approach has to be adopted with reassurance of the patient and therapeutic management of their symptoms

• HOMECHECK—If you cause pain during an IDB injection in your patient, do follow them up the next day and check they are OK. If the patient reports numbness, altered sensation and/or pain, reassure them.

• Continue to support, reassure your patient and advise them to visit to confrm the presence of neuropathy. If the neuropathy affects most of the dermatome ± associated with severe neuropathic pain, nerve injury must be suspected. Reassure your patient that 75% of these injuries resolve.

	- High-dose oral NSAIDs (400–800 mgs Ibuprofen PO QDS) for 2 days only. Bandolier Oxford league table summarizes the optimal analgesia for postoperative pain, and combined Ibuprofen and paracetamol have the smallest number needed to treat.

#### **25.3 Implant-related Nerve Injuries**

Implant-related IANI's incidence varies from 0–40% [37]. Two recent studies highlight persistent neuropathic pain due to implant IANIs [38, 39]. Prevention of nerve implant IANIs can be attributed to the avoidance of direct damage to the Inferior dental canal (IDC) during preparation [40]. A good clinical and radiographic pre-assessment protocol is required to mitigate damage due to proximity of implant bed preparation to the inferior dental canal (IDC) and are recommended [41, 42]. The risk factors for implant nerve injury are summarized in Table 25.2 [41, 42, 45–52].

A limited window is available to maximize inferior alveolar nerve injury resolution in relation to dental implants, endodontics and mandibular wisdom teeth. A report illustrated that early removal of implants (within 30 h) may maximize neuropathy resolution; however, the evidence remains weak [37]. Prevention of implant-related nerve injuries includes;

	- undertake a good risk assessment,
	- ability to read and use CBCT to plan a suffcient safety zone (know difference between drill length and implant length),
	- extra diligence in planning implants in the parasymphyseal region near the mental nerve (loop and incisal branches),
	- Screen out neuropathic pain pre-implant.
	- make sure the implant bed preparation is above the safety zone,
	- stop drilling if patient reports intraoperative pain and reassess depth,
	- use drill guides and stops,

#### **Table 25.2** Risk factors for implant-related nerve injury

	- intra-operative reassessment of implant bed depth using marker and LCPA flms at 60% of planned depth,
	- Record any events that may indicate operative nerve injury,
	- extreme pain during LA IDB, or during implant bed preparation
	- Suddenly give and/or profuse haemorrhage arising from the implant bed (possible breech of IDC).
	- In such situations, stop surgery, do not reach for more LA and reassess your surgical position,
	- Continue to support and reassure your patient and advise them to visit return to your clinic. If the neuropathy affects most of the dermatome ± associated with severe neuropathic pain, nerve injury must be suspected.
	- Say SORRY this is NOT an admission of guilt. When neuropathy is confrmed, check who you must notify as in many countries, IANIs are reportable events. It is essential to be honest with your patient.
	- Additional scanning or radiography may not be essential. Post-traumatic neuropathy is a clinical diagnosis. You will already be aware of the proximity of the implant bed to the IDC, and whether there was likely breach into the IAN canal.
	- If nerve injury is suspected, the implant must be removed within 24–36 hours of placement in order to maximize recovery from nerve injury [37].
	- Arrange a review of the patient to confrm neuropathy.
	- Initiate medical management (recommended for other peripheral sensory nerve injuries).
		- High-dose oral NSAIDs (400–800 mgs Ibuprofen PO QDS) for maximum 2 days.
		- GMP (General Medical Practitioner) prescription for Prednisolone 5 day step down does 50-40-30-20- 10 mg PO (not for patients with contraindications for steroids or NSAIDs).
		- Vitamin B complex (Ribofavin 400 mg once daily for a maximum of 3 months plus other Vit B complex).

#### **25.4 Mandibular Third Molar Extractionrelated Nerve Injuries**

The nerves at risk of damage in mandibular third molar extraction are the terminal nerves of the third branch of the trigeminal nerve [53, 54], i.e. the inferior dental nerve (IDN) and lingual nerve (LN). The reported risk of neurosensory defcit ranges from 0.26 to 8.4% for IDN [55] and from 0.1 to 22% for LN [ 7]. Patients with IDN injury suffer from paresthesia, anaesthesia or dysesthesia in the lip, chin or gingiva on the affected side, while patients with LN injury have a sensitivity defcit at the homolateral half of the tongue, with or without taste alteration [ 7]. Transient and permanent lesions should be differentiated; permanent lesions often remain after 6–12 months, and spontaneous recovery cannot be expected in these cases [ 56].

Damage to the LN or IDN during third molar extraction is among the most frequent causes of litigation in dentistry [57]. Highly varying results have been published by numerous studies on risk factors related to neurosensory defcit in lower third molar surgery. The objective of a recent literature review was to identify and analyse studies on factors related to IDN and/or LN injury in lower third molar extraction, allowing clinicians to take appropriate measures to minimize this risk [58]. Several radiological risk factors have been identifed that increases the risk of nerve injury during removal by ten-fold (from 0.2 to 2% permanent injury and 2–20% temporary nerve injury) [59, 60].

#### **Key Facts**

Factors that may be implicated in nerve injury after lower third molar surgery were classifed into four groups:


#### **25.4.1 Risk Assessment**

A recent review included three cohort studies and various randomized clinical trials (RCTs) on the infuence of diagnostic radiographic techniques. They generally reached similar conclusions, fnding that the non-utilization of CBCT was not an additional risk factor for nerve injury in patients examined by conventional panoramic radiography [61–63].

Korkmaz et al. [64] and Lee et al. [65] reported a lower frequency of transient but not permanent IDN damage when CBCT was also used. This may be because in cases where the relationship between third molar and the IDN is doubtful, there is likely to be no direct contact and the injury would result from pressure due to haemorrhage or haematoma so that the association would be less detectable on panoramic radiology. In contrast, cases of direct contact are readily observed using both radiographic techniques.

#### **25.4.2 Patient Factors**

Various authors reported a signifcantly lower frequency of nerve injury with younger age. [66–70] Thus, no cases of nerve injury were observed among patients under 23 years of age in the cohort study of 1050 patients by Zhang et al. [ 71], while Kjolle et al. [66] confrmed a signifcant association with age (*p* = 0.007), fnding a higher frequency of permanent injury in patients over 30 years of age. These fndings may be attributable to an increased diffculty of the surgery at older ages due to a greater likelihood of hypercementosis, lower bone elasticity and, above all, completed root formation, in addition to lesser vascularization, reducing the regenerative capacity of the nerve. Nevertheless, other researchers found no signifcant relationship with age [72] although the sample sizes were smaller than that in the aforementioned studies. All reviewed articles observed a higher frequency of nerve injuries in females [62] although this difference was only statistically signifcant (*p* = 0.005) in the multiple logistic regression analysis of 320 cases conducted by Selvi et al. [68] Gender differences have been attributed to the generally smaller mandible of females, implying a smaller gap between third molar root and IDN.

#### **25.4.3 Anatomical**

The mandibular canal is evidently more susceptible to nerve injury with greater depth and, therefore, closer proximity of the impacted third molar, reducing the surgical accessibility and visibility. A statistically signifcant association was demonstrated by all three articles that studied this risk factor [62]. A higher risk of IDN injury was associated with mesioangular impactions and with horizontal impactions [62], but these associations were not found to be statistically signifcant.

#### **25.4.4 Radiological Factors**

In 1990, Rood and Shehab [59] proposed seven radiological signs identifable by panoramic radiography, which indicate a close relationship between lower third molar and IDN: root narrowing, root darkening, apex darkening and bifd images, changes in root direction, dental canal narrowing, dental canal diversion and interruption of the white line of the dental canal. Only four of these signs were reported to be signifcant indicators of IDN risk in the reviewed articles: interruption of the radiopaque band of the canal [62, 66, 69, 73–76], canal diversion [59, 74, 76], root darkening [59, 62, 74, 76] and mandibular canal narrowing. [70, 74, 76] In contrast, a retrospective study by Pippi et al. [72] found that none of these signs were signifcantly associated with nerve injury, even when two or more were observed. CBCT radiological signs have also been associated with IDN damage. Detection of contact between lower third molar and mandibular canal has been found to potentially infuence the resulting nerve damage, [62, 68, 69, 72, 77] which is associated by Kim et al. [70] with a 21-fold higher risk of paraesthesia. Various studies [67, 69, 73, 78, 79] have associated nerve injury with the lingual position of the mandibular canal with respect to the third molar root, attributed to the more likely interruption of the mandibular canal cortex due to the direction of extraction manoeuvres. The RCT reported by Ghaeminia et al. [ 62] found the risk of nerve injury to be 16-fold higher when the localization was lingual versus buccal. In addition, some authors have described a higher risk of IDN injury for dumbbell-shaped versus round-, oval- or drop-shaped canals [72, 73, 76, 77].

#### **Key Facts**

There are seven radiological signs identifable by panoramic radiography, which indicate a close relationship between lower third molar and IDN: root narrowing, root darkening, apex darkening and bifd images, changes in root direction, dental canal narrowing, dental canal diversion and interruption of the white line of the dental canal.

#### **25.4.5 Surgical**

Two studies related the type of anaesthesia to IDN injury. Nyugen et al. [67] found a signifcantly higher (*p* = 0.007) frequency of permanent damage in lower third molar surgery under general versus local anaesthesia, and Costantinides et al. [80] reported a 2–16-fold greater risk of IDN injury under the former. One explanation is that the absence of patient feedback with general anaesthesia means that surgeons are less aware of the force applied. Hasegawa et al. [69] observed a signifcantly higher (*p* < 0.05) IDN injury rate in patients with versus without nerve exposure during the surgery. However, Pippi et al. [72] reported nerve injuries in only 6.5% of cases in which the nerve was exposed versus 9.3% of cases in which it was not, suggesting that IDN exposure may simply refect the close proximity of tooth and nerve and cannot per se be considered an indicator of potential nerve damage. Three studies associated haemorrhage during third molar extraction with IDN injury [62, 75, 81], without elucidating whether the bleeding resulted from mandibular canal fracture or a haematoma or other causes of nerve compression.

With respect to the experience of the clinician, Nguyen et al. [67] found a signifcantly higher frequency of permanent IDN injury (*p* = 0.026) amongst inexperienced dentists in comparison to oral specialists or maxillofacial surgeons, possibly related to inappropriate force and less instrumental control in the hands of those with less experience. The same study also explored the effect of surgery duration, fnding a higher nerve injury rate when this was more than 20 min (from incision to completed tooth extraction), mainly because a longer surgical time implies a more challenging extraction. With regard to the surgical approach, Jain et al. [73] reported a signifcantly (*p* = 0.04) higher nerve injury rate in patients who underwent odontosection versus those who did not. This may be explained by the less extensive ostectomy often associated with this procedure although odontosection can be a direct risk factor for IDN injury in the extraction of horizontal third molars [82].

#### **25.5 LN Injury Risk Factors**

*Demographics* A prospective study by Charan Babu et al. [83] reported that older age was a signifcant risk factor for LN injury (*p* < 0.05), but Kjoelle et al. [66] found no differences in permanent nerve damage amongst age groups. No signifcant gender differences in LN injury rate were found in any study.

*Anatomical* Charan Babu et al. [ 83] observed a signifcantly (*p* < 0.01) higher risk of LN injury with greater impaction depth, attributed to the more diffcult extraction and, therefore, more extensive osteotomy. A higher LN injury rate was observed for distoangular impactions [67, 83] generally due to the more diffcult extraction and for horizontal extractions [83], possibly because of the larger amount of bone removed. However, these associations were not statistically signifcant.

*Surgical* Charan Babu et al. [ 83], Osunde et al. [84] and Yadav et al. [85] reported a significantly higher LN injury rate (*p* < 0.01, *p* < 0.001 and *p* < 0.001, respectively) in patients who had undergone lingual flap retraction before third molar extraction than in those who had not.

This injury was found to be transient in the RCT by Shad et al. [86], who suggested that permanent injury can be produced when the lingual fap is not separated from the bone. Three studies [62, 85, 87] observed a signifcant association between higher LN injury risk and the requirement for odontosection in third molar surgery.

#### **25.6 Role of Alternative Surgical Techniques**

Various authors have proposed alternative surgical techniques to avoid nerve damage in lower third molar extraction, but their fndings should be considered with caution due to major study limitations (e.g. no control group and small sample size), and there has been little research on this issue. In a study of 53 patients, Bataineh et al. [88] reported a modifed fap that appeared to reduce LN lesions caused by fap retraction, considering all known anatomical variations of LN. Ge et al. [89] observed lower nerve injury rates when type III lower third molars in lingual position were extracted by piezosurgery in a lingual split approach in comparison to published rates reported using the conventional lingual split technique. The persistence in defending lingual access third molar surgery is inappropriate, in that it signifcantly increases the risk of temporary lingual nerve injury and 10–12% of these injuries will be permanent [90]. A recent literature review recommends avoidance of lingual faps in third molar surgery to minimize lingual nerve injury [91].

A recent surgical technique to mitigate the risk of high risk third molars in close proximity to the IDC is a coronectomy. Coronectomy, in which the dental crown is removed and the root is retained in the jaw, has been recommended to reduce IDN injury risk in cases of close proximity between nerve and third molar, and the majority of the reviewed studies described any IDN injury with the utilization of this approach [60]. Nevertheless, this technique is not free of controversy, even when clearly indicated, given the possibility of infectious complications around the root or its migration [92–95]. Extraction by orthodontic traction may also be useful when there is a high risk of nerve injury, and Wang et al. [96] found no cases of nerve injury in patients undergoing this procedure although account should be taken of study design limitations and the small sample size. There is a strong evidence base to support the prevention of IDN nerve injuries using the coronectomy technique [43, 44, 53, 54, 97].



Summary prevention of third molar surgery-related nerve injury (Table 25.3) [98, 99].


#### **25.7 Prognosis of Nerve Injuries**  (Table 25.4) [43]

It is not possible to classify the degree or outcome of a sensory nerve injury based on patients' presentation early postinjury. Just as with phantom limb pain patients, who may express non-existence or existence of a 'normal feeling' limb (after amputation, the most catastrophic nerve injury) with or without pain, numbness or altered sensation, these symptoms do not refect the degree of injury or prognosis. Thus, in order to assess the end results of nerve injury, the patient must be reassessed and/or treated if indicated. The type and **Table 25.4** Resolution rates of inferior alveolar nerve injury (IANI)


A review of common operations such as groin hernia repair, breast and thoracic surgery, leg amputation and coronary artery bypass surgery found an incidence of chronic post-surgical pain in 10–50% of patients [100].



A known or suspected sectioned/damaged nerve should undergo immediate exploration repair

related permanency of trigeminal nerve injuries are summarized in Table 25.4.

*Summary of type and timing of management* (Table 25.5 and Fig. 25.2) Management of third molar-related nerve injuries will depend upon the presentation of the patient (pain, functional and psychological implications) duration and cause of the nerve injury [56, 98]. Figure 25.2 summarizes the management and timing of intervention for trigeminal nerve injuries based upon the current evidence base [56, 98]. It is recognized that neuropathic pain does not respond to surgical intervention, and thus, prevention and early management are paramount in preventing chronic life-long pain after routine surgery in these patients. Advice is summarized on the Trigeminalnerve.org.uk website.


• New developments

• MRI micro neurography may assist in confirmation of damage to IAN and LN (currently available in US under development London) .

• Larger IAN defects can be optimally repaired using Axogen cadaveric nerve graft (currently NICE approved for hand surgery in UK)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 25.2** suggested management of nerve injuries related to mandibular third molar surgery

The patient with the nerve injury must be treated, NOT the nerve injury in isolation. The neuropathy, pain, numbness or pareasthesia, with associated functional and psychological impact, will be the driving force behind the patient seeking treatment [98]. These factors must be assessed, and the potential outcomes, good or bad, should be discussed and agreed with the patient [99].

Patients sustaining LA, orthognathic, oncology and trauma-related nerve injuries will mainly be managed therapeutically [101–104].

Overall, there is poor evidence to support late surgical intervention for Trigeminal nerve injuries [6, 105]. Most studies report on repair procedures undertaken too late, and early repair is imperative to minimize central irreversible changes and possibly chronic pain. Generally, surgical repair of the trigeminal nerves never returns the patient to peroperative neural function; in addition, there is a risk of making a numb patient into one with chronic post-surgical pain [100, 106]. As with other post-trauma sensory neuropathies, it is recognized that immediate repair is optimal; [107, 108] however, this is rarely applied to dental nerve injuries with the misconception that we should sit and wait for resolution (only for 3 months for lingual nerve injuries related to lingual access third molar surgery), resulting in long delays before surgical intervention [109–111].

Some recent studies have highlighted immediate repair with cadaveric-treated human nerve graft successful in managing various sized defects in planned resection of nerves related to benign tumour resection or trauma [112, 113].

Recent reports have also concluded that, similar to other surgical sites, neuropathic pain does not resolve with surgery, with this being the main driver for surgical repair [114, 115].

Many reports have recommended the use of conduits (venous, prosthetic), sural nerve grafts and other techniques without suffcient evidence and many with poor outcomes including neuropathy and pain from the donor sites! The future may prove that nerve growth factors, other growth-promoting chemical and anti-neuropathic pain agents and specialized conduits may play a role in improving repair of trigeminal nerve injuries, and the overall conclusion from reviews in this area is that we have a lot of evidence base to harness [105, 106, 116]. The singular consensus is that prevention of these nerve injuries is possible and optimal.

The timing of intervention and mechanism of injury are paramount in decision making in the treatment of trigeminal nerve injuries (summarized in Table 25.5).

	- acute (medical),
	- late (chronic pain management with psychological interventions).
	- Immediate surgical repair for suspected or known nerve injury or intended surgical defect after removal of benign tumour or recent trauma [98].
	- Removal of implant.
	- or overfll or RCT-treated tooth with 36 h if related to the development of neuropathy [99].
	- Within 2–4 week, exploration if clinical presentation of persistent neuropathy is paramount and radiographic follow-up is not necessary; however, if there is CBCT evidence of breech of lingual plate or IDC, consider immediate action-nerve exploration ± repair;
	- Lingual nerve neuropathy patients with CBCT evidence of damage to lingual plate adjacent to third molar surgical site.
	- Inferior alveolar nerve with retained roots or evidence of bone inclusions or compression of IDC.
	- Within 3 months of injury;
	- Non-resolving lingual or inferior dental nerve injuries: Exploratory surgery for lingual or inferior alveolar nerve injuries within 3 months post-injury. Surgical intervention is not effective for neuropathic pain, and if this is the driving force behind seeking surgery, it should be reconsidered.
	- There are reported exciting results of allografting lingual and inferior alveolar nerve injuries. Using a preprepared human-treated cadaveric allograft, the IDN and LN can be repaired with minimal tension. This is undertaken using microscopy and described in several publications by John Zuniga and Michael Miloro [109]. This is likely to be the treatment of choice if repair is indicated and direct re-anastomosis cannot be undertaken most commonly for the IDN. One of the

main issues regarding nerve repair is the early identifcation of the neuroma related to the patients 'symptoms and the connectivity of the nerve itself, i.e. is the nerve actually functioning. Recent developments with Magnetic Resonance Neurography (MRN) have availed the surgeon to identify the nerve lesion and neural functionality to facilitate appropriate and earlier nerve repair intervention [117, 118].

#### **25.8 Conclusions**

Unfortunately, none of these interventions 'fx' the patient, but the aim is to manage their symptoms as best as possible, improve function and allow them time to accommodate to these unfortunate events, which is often not very satisfactory.

This chapter was intended to acknowledge and share some key issues around iatrogenic trigeminal nerve injuries and to provide some key take home messages including:


#### **References**


reduced (1/400,000) articaine solution in short-time dental routine treatments--a multicenter study. Clin Oral Investig. 2012 Aug;16(4):1289–95.


Oral Maxillofac Res. 2013 Jul 1;4(2):e2. https://doi.org/10.5037/ jomr.2013.4202.N.


post-operative inferior alveolar nerve paresthesia after third molar extraction. J Clin Diagn Res. 2014;8(5):ZC624.


Apr;73(4):734–744. https://doi.org/10.1016/j.joms.2014.10.030. Epub 2014 Nov 13.


nerve repair. J Oral Maxillofac Surg 2014 Dec;72(12):2422–2427. https://doi.org/10.1016/j.joms.2014.08.003. Epub 2014 Aug 11. PMID:25308410.


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The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

**26**

## **Trigeminal Neuralgia**

Kandasamy Ganesan and Asha Thomson

#### **26.1 Introduction**

Neuralgia can be defned as paroxysmal, intense intermittent pain that is usually confned to specifc nerve branches of the head and neck. The trigeminal nerve is responsible for sensory innervation of the scalp, face and mouth, and damage or disease to this nerve may result in sensory loss and/or pain. Trigeminal Neuralgia (TN), also referred to as 'Tic Douloureux,' is sought to be the most intense and wellknown neuralgias, which displays classical features of intense sharp, stabbing sensations with or without burning pain throughout the face. It is considered as one of the most chronic painful conditions known within the body. The pain, which is often initiated by just a light touch to an area of skin, can occur at any time without warning and depending on the severity of the condition, the frequency of the attacks can vary.

This severe medical condition affects one or more branches of the ffth cranial nerve known as the trigeminal nerve, which is the largest cranial nerve and has both sensory and motor functions. >85% of cases of trigeminal neuralgia are of the classic type known as classical trigeminal neuralgia (CTN), while the remaining cases can be separated to secondary trigeminal neuralgia (STN). STN is thought to be

K. Ganesan (\*)

University of Leeds, Leeds, UK e-mail: mailme@kandyganesan.com

A. Thomson (\*) Norfolk and Norwich University Hospitals, Norfolk, UK e-mail: ashathomson1@nhs.net

initiated by multiple sclerosis or a space-occupying lesion affecting the trigeminal nerve, whereas the leading cause of CTN is known to be compression of the trigeminal nerve in the region of the dorsal root entry zone by a blood vessel.

Investigation of the cause of the neuralgia present and treatment planning of these symptoms can pose a challenge for any clinician and the importance of detailed assessment and history taking of orofacial pain should be highlighted. Extreme care must be taken to identify the underlying cause of the symptoms experienced by the patient, who may often present in distress, as suffering from head and neck neuralgia can severely affect a patient's quality of life.

There is no guaranteed cure for the condition of trigeminal neuralgia, but there are several treatment options that may give symptomatic relief. In this chapter, we will review the common neuralgias occurring within the oral and maxillofacial region with specifc emphasis on trigeminal neuralgia. We will discuss the historical evolution of treatment including the medical and surgical modalities with the use of current literature and newer developments. This highlights the need for further studies and investigation into the phenomenon of neuralgia to improve patient management and treatment outcomes.

This chapter will also cover surgical interventions such as, peripheral neurectomies, which can be done by an Oral and Maxillofacial Surgeon.

#### **26.2 Anatomy of the Trigeminal Nerve**

This is the largest cranial nerve with both sensory and motor components. It provides sensory nerve supply to the face, the scalp, the nasal cavity and the oral cavity including the teeth. It carries proprioception from the periodontal ligaments of the teeth and masticatory muscles. The trigeminal nerve provides motor supply to the muscles of mastication, tensor tympani, tensor veli palatini, mylohyoid and anterior belly of digastric. Its name is derived from its three main

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_26) contains supplementary material, which is available to authorized users.

Department of Oral and Maxillofacial Surgery, Southend University Hospitals NHS Trust, Southend-on-Sea, UK

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 531

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_26

©Association of Oral and Maxillofacial Surgeons of India

branches ophthalmic, maxillary and mandibular. This nerve can be divided into various anatomical segments by its course from the brain stem, cisternal, Meckel's cave, ganglionic and fnally to peripheral divisions (Ophthalmic, maxillary and mandibular). For trigeminal neuralgia, understanding of the anatomy of cisternal and Meckel's cave segments is important.

The trigeminal ganglion is located in the Meckel's cave, which is a recess between the two layers of the dura in the posteromedial portion of the middle cranial fossa. Any disease process in and around the Meckel's cave can develop the symptoms of trigeminal neuralgia. The anatomy of the Meckel's cave is detailed through the use of Fig. 26.1.

Arachnoid membrane from the posterior cranial fossa extends into the Meckel's cave and continues along the rootlets of the trigeminal nerve to as far as the trigeminal ganglion [1].

#### **26.2.1 Peripheral Distribution of Trigeminal Nerve (Fig. 26.2 and Table 26.1)**

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 26.2** Diagram showing peripheral distribution of trigeminal nerve

**Table 26.1** Branches of the 3 divisions of the trigeminal nerve


#### **26.3 Aetiology of Trigeminal Neuralgia**

#### **26.3.1 Neurovascular Compression**

Myelin sheath surrounds the cranial nerves formed by oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system. The main function of the myelin sheath is to provide mechanical insulation and metabolic support for the axons. This myelin sheath at the transition zone (TZ), between the central and peripheral nervous systems is a vulnerable area in the context of neurovascular compressions. The TZ is more relevant and not always located in the same position as root entry zone (REZ) [2].

Neurovascular compression at the REZ is found to be a reason for 80% of the TN but not a consistent fnding in all the TN patients. This neurovascular contact at the REZ is also found in non-TN patients. A superior cerebellar artery alone or in association with another vessel is found in 88% as a source for vascular compression. Other vessels such as anterior cerebellar artery, the basilar artery and vertebral artery are also found to be in contact with RTZ [3].

#### **26.3.2 Multiple Sclerosis (MS)**

In 1950, the frst fnding of a connection with multiple sclerosis is reported [4]. A comprehensive review of pain in MS patients identifed the prevalence to be TN to be 3.8%, which is lower than headaches (43%) and neuropathic extremity pain (26%) [5].

From this review, TN was the frst symptom of MS in 9–14% of patients and the mean age of onset ranged from 33 to 51, highlighting younger patients than patients with TN alone. In addition to this, TN due to MS is often associated with numbness and paraesthesia [6]. Neuralgic pain, over a period of time, evolves with atypical features and involves an increase in the number of divisions of trigeminal distribution. Additionally, 6% became bilateral and literature shows MS precedes TN, however several studies showed TN as a frst symptom before any other MS symptom [7, 8].

Electrophysiologic testing of MS-related TN patients showed up to 89% abnormal trigeminal refexes such as the blink refex compared to 3% in idiopathic TN patients. In MS, plaques result in neural damage causing TN but not as a result of neurovascular compression however, both can play a role in the aetiology of TN [9].

In MS, ephaptic nerve conduction is effected due to an increase in infammatory activity in the plaques with a high T-cell activity [10].

#### **26.3.3 Tumour and Cyst**

Tumours alone are shown to be aetiology in TN from 0.8 to 11.6%, but this increased to 5.7 to 13.4% when aneurysms, angiomas or vascular malformations are present. Tumours may cause TN by compression, wrapping around the nerve root, neurovascular compression and/or neoplastic factorrelated chemical irritation [6].

#### **26.3.4 Diabetes Mellitus**

The involvement of diabetic neuropathy is more common in the 3rd, 4th and 6th cranial nerves than in the trigeminal nerve. Diabetic patients tend to have more of a neuropathic pain than neuralgic pain, which may present as hot, burning, electric with a pins and needles sensation, especially in the peripheral areas such as the hands and legs. Often, this tends to be bilateral, and may present worse at night [11].

Hyperglycaemia is known to cause aggravated nerve damage, and this also applies for the increased risk of developing TN however, more studies need to be done in order to validate the underlying pathophysiology between the association of diabetes and TN [12].

#### **26.3.5 Herpes Simplex**

Post-herpetic TN after herpes zoster-shingles has been documented [13] and can present as a burning persistent severe pain for the patients. The reactivation of the latent herpes zoster virus from the dorsal root ganglion results in TN affecting the ophthalmic branch in over 80% of cases. When antivirals are administered within 72 h from the onset of the rash, they are known to reduce the duration of the rash, pain and also the incidence of post-herpetic neuralgia [14–17].

#### **26.4 Pathophysiology of TN**

The exact aetiopathogenesis of TN remains unclear. The most common hypothesis is the "ignition theory," which is a result of abnormalities in the afferent neurones of the trigeminal root or ganglion. Injury to the axons can make them hyperexcitable and also cause central sensitisation, leading to TN [18].

Demyelination at the trigeminal REZ where central and peripheral myelin meets results in generation of ectopic impulses. This in turn can cause cross-talk between touch and pain sensations which is thought to decrease the central pain gating mechanisms. Which, can conversely result in trigeminal nerve remyelination. This may explain the spontaneous remission in some patients; however, the same cannot be applied for rapid electrophysiologic recovery and pain relief after microvascular decompression treatment [6].

The affected (demyelinated) nerves can spontaneously discharge electric impulses. Touch sensation carrying A-β fbres aligned near the pain carrying (nociceptive pathway) A-δ and C fbres in the REZ, leading to ephaptic cross-talk between the two pathways. This may explain how trivial touch sensation triggers pain in TN [18].

The trigeminal ganglion itself can show pathological changes such as hypermyelination [19, 20]. Demyelination is common in many patients with TN and is caused by a compression by vascular structures, MS, tumours and vascular malformations.

Compression on the REZ should cause a continuous pain, but TN patients suffer paroxysmal attacks, which are most likely to be caused by spontaneous discharges where the threshold for the repetitive fring has been altered. It is also notable in TN that such fring occurs not only spontaneously but also by trivial tactile stimuli. This type of fring behaviour is also observed within in dorsal root ganglions [20].

Rappaport and Devor [21] explained that the development of atypical features of the TN may be due to central sensitization following a prolonged barrage of nerve impulses and also from progressive damage to trigeminal afferents, which become the source of continuous ectopic discharges [20].

Interestingly, literature shows that different treatments of TN yield similar results in pain control however, the longterm results show that decompression provides prolonged pain relief compared to destructive peripheral procedures [20]. In addition, destructive procedures may cause some degree of sensory loss along with the same duration of pain relief [22].

#### **26.5 Historical Perspective**

Historically, reviews dating back to 2 AD demonstrates the existence of TN or a similar condition described by Aretaeus of Cappadocia, a contemporary of Galen. The same author is known for the description of migraine, and in the 11th century [23], an Arab physician Jujani describes a unilateral facial pain causing spasms and anxiety. He explains that the cause of the pain is 'proximity of the artery to the nerve' [24].

Wells Cathedral, an Anglican cathedral in Wells, Somerset, England, dedicated to St Andrew the Apostle, contains the tomb of Bishop Button, who died in 1274. He was canonized, and many pilgrims and toothache sufferers left offerings at the tomb, in commemoration of which the capitals of the pillars bear carvings of people depicted with facial neuralgia. One is famed as the toothache fgure and because of the surprising rarity of dental caries at that time (confrmed when the sarcophagus was opened in 1848), Wilfred Harris pointed out the probable relevance to trigeminal neuralgia [25].

A frst Royal account in relation to TN is by John Locke, the famous philosopher and physician who wrote a series of letters to Dr John Mapletoft in 1677 [26] describing TN suffered by Countess of Northumberland, wife of Ambassador to France.

Nicolas Andre invented the term *tic douloureux* in 1756 in a book, Observations pratiques sur les maladies de l'urethre et surplusiers faits convulsifs [27].

*John Fothergill* publishes the frst account of TN to the Medical Society in London in 1773 and described TN as a 'paroxysmal unilateral facial pain, evoked by eating, speaking or touching, starting and ending abruptly, and associated the condition with anxiety [23].

Between the eighteenth and nineteenth centuries, Pujol, Chapman and Tiffany completed the clinical picture and differentiated TN from other facial pain conditions. Later, Oppenheim highlighted the association between TN and MS [28].

Treatment of TN including microvascular decompression has been available since 1925 [29]; however, it took another 50 years to become an accepted neurosurgical intervention. During 1950 to 60, Gardner and Miklos [30] promoted neurovascular decompression theory and continued to modify the technique, but a major shift in this practice happened after a large clinical series published by Jannetta [31]. Throughout the last century, ablative neurosurgical procedures continued to evolve to balance the best possible outcome between pain control and adverse effects. The latest in this process is radiosurgery. And even although surgical practice was continuing to evolve, medical therapy had little success in the same period. In 1942, Bergouignan's discovery of phenytoin was the frst medical intervention in effective control of pain paroxysms [32]. In 1953, Walter Schindler discovered Carbamazepine and marketing was started in 1962. Although it was originally used for epilepsy, trials showed their effectiveness in TN pain control.

#### **26.6 Clinical Presentation**

Within the maxillofacial region, neuralgias can present in different severities and can affect patients from any race, gender and age. Certain conditions may be distinctive to certain groups of people, but there is no current classifcation followed for the diagnosis and management of neuralgic pain; however, groups do exist in order to distinguish the categories that they may be separated into.

These pain episodes experienced may last from seconds up to several minutes and can be described by the patient as an 'electric shock' feeling. This sensation may occur frequently per day (up to hundreds of times) over weeks and months and then suddenly stop with pain-free periods in between. It may also present infrequently with periods of remission, which may possibly last for years [13]. The pain often occurs unilaterally, does not usually cross the midline of the face and is often unbearable for the patient. It has been shown that only 3% of cases are known to be bilateral in nature [13].

#### **26.6.1 Risk Factors**

#### **Sex**

It has been highlighted that TN affects females more than males [13].

#### **Age**

In patients over 80 years old, males tend to have a higher incidence (45/100,000) [13, 33–36].

It can be prominent within all age ranges, but most frequently, TN affects individuals over the age of 50. Approximately 70% of the patients develop TN after they reach 60 years of age and it is known that the incidence of TN increases with age, and has been emphasised that this condition is rare to affect people younger than 40 years old [36, 37]. This is therefore highly important in suggesting that multiple sclerosis may be present in younger patients who suffer from TN [38].

#### 535

#### **26.6.1.1 Initiating Factors**

The pain felt can be precipitated by trigger areas or factors of light touch on specifc areas of the face, and patients often avoid these actions, which they may feel causes the attacks.

These activities may include: Shaving Applying make-up or face cream Brushing the teeth Speaking Smiling Yawning Face washing Swallowing Vibration Exposure to cold such as cold wind, breeze on the face or air conditioning Eating, chewing or biting into something Touching or washing certain areas of the face

#### **26.6.2 Prevalence**

A systematic review highlighted that the range of TN prevalence was 0.03–0.3%, mostly women were affected, and the affected age range was 37–67 years old. The affiction was marked by unilateral symptoms, most commonly in the maxillary and mandibular branches [39].

NICE guideline data and studies [13] indicate that a survey carried out within general practice in the United Kingdom, which highlighted that the annual incidence of trigeminal neuralgia was 8 per 10,000.

The true prevalence of this condition remains unclear as there is little data to support the evidence of how common this condition is [13]. It is evident that even with studies carried out, further research is required to validate the prevalence of trigeminal neuralgia due to the complexity of the condition including diagnosis diffculties and heterogeneity of the disease characteristics [39].

#### **26.6.3 Clinical Diagnosis**

#### **26.6.3.1 Pain History**

Accurate diagnosis relies greatly on a detailed history of symptoms from the patient, with pattern and nature of the pain highlighting the condition as there is no defnitive diagnostic test yet available. SOCRATES is a useful assessment tool (Table 26.2), which is often used to help clinicians in achieving an accurate pain history.



Trigeminal neuralgia may be misdiagnosed for dental pathology, and so it is important that unnecessary dental treatment is not carried out without full investigation of the source of the pain. When patients suffer from the condition, it often becomes apparent that their quality of life decreases as they may be unable to carry out their normal daily activities and suffer from weight loss due to problems in eating, and as a result the condition may lead to depression and/or isolation.

On clinical examination, trigeminal refex testing may be used to test all three divisions of the nerve and may reveal loss of sensitivity in the cutaneous region, which may be related to the affected nerve. This may present as partial numbness (hypoesthesia) or complete numbness (anaesthesia) and occasionally may present as hyperaesthesia causing considerable discomfort.

*The classical symptoms of trigeminal neuralgia are as follows:*


#### **26.6.3.2 Other Causes**

Trigeminal neuralgia can occur as a result of several causes such as trauma, tumours, infectious or demyelinating diseases, connective tissue diseases and can also be idiopathic in nature. This poses a challenge to the clinician when trying to investigate the cause of the pain. The importance of the causative factors may highlight the possibility that trigeminal neuralgia can present as the frst manifestation of an underlying systemic disease. This emphasises that careful and in-depth investigations with detailed history taking are required in order to appropriately treat this life-affecting condition. A referral to a specialist in pain management or neurologist should be considered in severe cases [13, 38].

As trigeminal neuralgia is uspected when a patient has severe and intense pain in the orofacial region, other reasons may need to be explored for patients who have physical signs of motor or sensory problems. Neoplasms, infective conditions such as HIV, multiple sclerosis and even cerebrovascular disease may cause neuralgic pain, and so it is important to be aware of the differential diagnosis that could be derived from neuralgia within the head and neck.

TN is restricted to one or more branches of the trigeminal nerve distribution with an exception of TN in MS patients, where one side of the face may be affected. It is sudden in onset and typically lasts for a few seconds to a maximum of 2 min. Pain can be spontaneous but can also be triggered by innocuous mechanical stimuli or facial movements. In between the episodes, patients can remain pain-free and very rarely, patients suffer continuous pain in TN.

#### **26.6.4 Glossopharyngeal Neuralgia**

Glossopharyngeal neuralgia (GPN) is a rare uncommon painful neuralgic condition involving pharyngeal/orofacial region including the ear, base of the tongue, tonsillar fossa and submandibular region. It has similar etiopathogenesis to TN with neurovascular compression and demyelination of the 9th or the 10th cranial nerves. The prevalence rate is 0.2– 0.7 per 100,000 and accounts for 0.2–1.3% of the orofacial neuralgias [40].

Clinical history taking is important to differentiate different types of neuralgias. GPN clinically presents as a unilateral, severe and paroxysmal pain involving the ear, base of the tongue, tonsillar fossa and submandibular region. Painful symptoms are described very similar to TN symptoms such as, sharp, stabbing or electric shock like pain. Similar to TN, GPN is triggered by innocuous stimuli/function like swallowing, chewing, talking, coughing and yawning.

According to the criteria put forward by the International Classifcation of headache disorders (ICHD) [41]:

	- recurring in paroxysmal attacks lasting from a fraction of a second to 2 min
	- severe intensity
	- electric shock-like, shooting, stabbing or sharp in quality
	- precipitated by innocuous stimuli to the affected side of the face

The International Association for the Study of Pain (IASP) current classifcation


The readers may access the detailed classifcation at the following open access publication [42]. https://doi.org/10.1007/ s40265-018-0964-9.

#### **26.7 Investigations**

A thorough pain history and a clinical examination including cranial nerve examinations are important for the diagnosis of TN due to the fact that MS and tumours may be found in this cohort. Any defciency in the cranial nerve examination, especially a sensory loss, should prompt further imaging.

In order to rule out possible diseases, specifc tests may be carried out in adjunct by radiographic examinations such as plain radiographs including intra-oral (periapicals) and orthopantograms. These may be carried out in the frst instance to rule out dental pathology, and orthopantograms may also be able to detect temporomandibular joint pathology. Cranial computed tomography scan (CT) may also be used in order to identify any changes of the maxillary sinus.

Magnetic resonance imaging (MRI) is an important investigation to investigate and to differentiate between patients suffering from trigeminal neuralgia due to tumours and MS [18]. It may demonstrate the close and potentially causative relationship between the trigeminal root and adjacent blood vessel and can be of specifc value to exclude posterior cranial fossa lesions [38]. TN caused by MS should be ruled out, specifcally in the younger patient, and this may be aided by MRI. Clinical Knowledge Summaries (CKS). NICE [13] guidelines recommend MRI assessment specifcally for younger people, patients presenting atypical symptoms, nonresponders to initial therapy or anyone for whom neurosurgery is being considered. Even though MRI is commonly used, from previous studies carried out, the suggestion of its sensitivity and specifcity seems to be variable [43–50]. As a result, emphasis is placed on the challenge in identifying the cause of trigeminal neuralgia as a relationship between the clinical symptoms and radiological fndings as this may not be clear.

In idiopathic forms of trigeminal neuralgia, it is typical for no cause to be detected with the patient having both normal neurological and MRI examinations, which can cause diffculty with treatment planning. MRI fnding of an aberrant loop of a blood vessel at RTZ is the most common cause, and this is reported in about 60–90% of the cases described in neurosurgical/neuroradiological series [51–54].

Meaney et al. have designed a set of specifc parameters to visualise the blood vessels using thin slices to create the reconstruction of nerve and vessel in any orientation. This is called magnetic resonance tomographic angiography (MRTA) [55]. This reconstruction between the vessels and the nerves allowed us to identify the neurovascular compression. In comparison to MRTA, MR angiography only provides image of the blood vessels. Meaney et al. then validated their fndings by comparing the MRTA fndings with surgical fndings. In a series of 52 consecutive cases, MRTA fndings were comparable to surgical fnding in 50 out of 52 cases. In four cases, MRTA misclassifed veins as arteries; otherwise, MRTA is a sensitive and specifc method in demonstrating neurovascular compression [44].

#### **26.8 Management**

#### **26.8.1 Medical Management**

It has been highlighted that frst line of treatment for trigeminal neuralgia is still pharmacological treatment. The desired outcome of these patients is to treat the pain experienced, manage the symptoms and with time preferably, eradicate these symptoms in order to improve the patient's quality of life. Where appropriate, referral to a specialist pain service and/or neurologist may be necessary with clear information and given to the patient.

There are several drugs that have been delivered systemically or topically in the use of treating trigeminal neuralgia, which include:

Baclofen Dextromethorphan Lamotrigine Gabapentin Pregabalin Sumatriptan Levetiracetam Eslicarbazepine Pimozide Proparacaine Tizanidine Tocainide Topiramate

The most common therapy of choice is Carbamazepine for pain control [56] and after carrying out a systematic review of the literature, The American Academy of Neurology and the European Federation of Neurological Societies support Carbamazepine (200–1200 mg/day) [57] as the frst-line treatment to be offered due to strong evidence supporting this pharmacological treatment. In addition to this, another drug of preferred choice is Oxcarbazepine (600–1800 mg/day) [57], which is known to have better tolerability and is also supported by existing guidelines [13, 58].

All the above drugs have been evaluated using RCTs, whereas other drugs such as capsaicin cream, phenytoin, clonazepam, gabapentin, oxcarbazepine, mexiletine and tramadol have been assessed from case reports and case series. Studies involving many of these drugs regarding the full beneft and effect on the treatment of trigeminal neuralgia are limited, and so further evaluation is required [59, 60]. The response to the drugs mentioned is unique to each patient, and it is evident that the doses also vary between patients in order to achieve a benefcial effect to counteract the symptoms experienced. It has been highlighted that it may be helpful for the patient to keep a pain diary in order to record episodes and help the patient and clinician identify possible trigger factors and timing of the pain. This may aid treatment planning and may give patients back a sense of control, which has been lost due to their condition.

#### **26.8.1.1 Carbamazepine and Oxcarbazepine**

Based on existing evidence, carbamazepine also known with the trade name 'Tegretol' is an anti-convulsant drug used primarily in the treatment of epilepsy [61] and remains the drug of choice for standard frst-line treatment of trigeminal neuralgia in patients over 18 years of age [13, 57, 58]. It is considered to be of diagnostic help if complete resolution or reduction of symptoms occurs after its use [38]; however, carbamazepine must be used prophylactically and continuously for long periods, with tiered dosages prescribed to suit individual patients in regard to their response. Carbamazepine should be used with caution, and as it not an analgesic, it is not appropriate to use this medication during a pain episode for relief as it will not have an analgesic effect on symptoms. Patients can often misinterpret what the purpose of the medication is, and so this in turn highlights the importance of patient communication. The mechanism of the medication, the instructions in terms of dosage titration, timing of effects and the possible adverse side effects associated with its use should be highlighted. From current guidelines such as— NICE [13], it has been advised that if no sinister or red fag symptoms are evident and carbamazepine is not contraindicated for the patient, then, the following dosage guideline can be offered:


Frequent side effects have been reported with the use of carbamazepine drug therapy with specifc emphasis on elderly patients [61–63]. When patients are treated with carbamazepine, it is strongly advised that a full blood count and liver function tests are carried out prior to starting treatment and then reviewed periodically in order to monitor the possible effects of the drug. Hyponatraemia, which refers to low sodium levels, is thought to occur in 20% of patients, and NICE guidelines [13] suggests that carbamazepine in concurrent use with sertraline can also increase this risk. Serum levels of the drug are not routinely monitored unless carbamazepine toxicity is suspected but within the \ British National Formulary (BNF), all information is available in regard to drug interactions, adverse effects and contraindications and cautions. Within primary care settings, this is the standard frst choice of treatment if the physician is confdent with the diagnosis; otherwise, it is advised to refer the patient to a secondary care specialist for further investigations and treatment.

In several studies, the effectiveness of carbamazepine was demonstrated with specifc outcomes found in the reduction of both intensity and frequency of the painful paroxysms [36, 57, 64–68]. In addition to this, the pharmacological drug of choice was found to be equally effective on the reduction of both trigger touch and spontaneous attacks [59, 66]. Due to the possible side effects from carbamazepine, oxcarbazepine may often be used as initial treatment due to the decreased potential drug interactions and possible greater tolerability acceptance [57, 63, 68].

#### **26.8.1.2 Gabapentin**

It is known for its effective role in the management of neuropathic pain especially post-herpetic neuralgia, but there is a lack of evidence on its role in the management of TN. There is one randomized-controlled trial showing improvement in pain control with fewer side effects. This study compared the use of combination of both gabapentin and ropivacaine injected to trigger points and gabapentin alone [18].

#### **26.8.1.3 Baclofen**

Baclofen is used to control the symptoms in MS, and therefore, it is generally accepted to use in TN patients with MS [59]. It may well control the symptoms without adding carbamazepine. Its side effects including sedation and loss of muscle tone and abrupt discontinuation may cause seizures and hallucinations.

#### **26.8.1.4 Lamotrigine**

Lamotrigine is used when Carbamazepine is not tolerated well, or it is used in addition to carbamazepine when it is not effective on its own. There is not enough evidence to support the use of lamotrigine from studies carried out with relation to patients with TN [18].

#### **26.8.1.5 Evolving Medical Therapy**

Due to the known diffculty in treating trigeminal neuralgia, new therapeutic modalities are being investigated and have been tried [57]. It has been evident from recent reviews [18] that the combination of the pharmacological drug gabapentin with the addition of regular ropivacaine injections into specifc sites, which may be 'trigger sites,' has had a positive outcome on pain control with an improvement in quality of life.

Botulinum Toxin A (BTX-A) has also been suggested as an effective treatment of trigeminal neuralgia from a systematic review [69] carried out on patients suffering from this condition. No major adverse events were reported, and it was concluded that with an approximate 60–80% reduction in mean pain intensity and frequency, this medical treatment may be a future recommendation. Cruccu and Truini [42] were in agreement with these fndings who have also reviewed the literature on possible medical treatments for Trigeminal Neuralgia. It was highlighted that there is possible increasing evidence for BTX-A injections as a treatment option, specifcally prior to considering surgical options or for patients who do not want surgery. In relation to this, it is emphasised that further evidence is needed with regard to this treatment option with more investigation and welldesigned studies to take place.

Finally, it has been highlighted that local anaesthesia injected into the specifc trigger area, 8% lidocaine spray and the use of intravenous infusion of fosphenytoin may be an option to provide temporary relief for patients suffering from severe pain [18].

#### **26.8.2 Surgical Management**

A successful surgical intervention of TN is determined by elimination of pain. Currently available surgical options are

	- (a) Open:
		- (i) Microvascular decompression
	- (b) Percutaneous:
		- (i) Radiofrequency rhizotomy
		- (ii) Retrogasserian glycerol rhizotomy
		- (iii) Balloon compression of trigeminal nerve
		- (iv) Stereotactic radiosurgery—Gamma knife
	- (i) Peripheral neurectomy
	- (ii) Alcohol injections
	- (iii) Cryotherapy
	- (iv) Selective radiofrequency thermocoagulation

#### **26.8.2.1 Microvascular Decompression (MVD)**

The original theory was outlined by Dandy in 1925, and vascular decompression of the trigeminal nerve was frst described by Gardner and Miklos in 1959 [70] and was further refned by Jannetta et al. in 1967 [71]. Advances in anaesthesiology, use of operating microscopes and evolving surgical techniques allowed the MVD as a safer and effective procedure. MVD further evolved in the next 50 years to become accepted as one of the best surgical options.

Surgical target is the trigeminal nerve-pons junction. To reach this target, the posterior cranial fossa needs to be accessed via suboccipital craniotomy. On entering via craniotomy site, cerebrospinal fuid will be aspirated. Further advancing is done towards the nerve by gently retracting part of the cerebellum (Fig. 26.3). It is common to fnd a segment of superior cerebellar artery compressing on the REZ. Less

**Fig. 26.3** Diagram showing suboccipital access

commonly, a variation with an anterior inferior cerebellar artery or the superior petrosal vein can be found as a cause of the neurovascular compression [72]. Once the vessel is freed of the REZ, a piece of Tefon is placed to keep the nerve and the vessel apart (Fig. 26.4).

Utmost care should be taken to avoid any post-operative hearing loss. This is usually done by monitoring the brainstem evoked potential as hearing loss is due to the pressure on the eight cranial nerve due to retraction. A timely release of retraction improves this and literature recommends the removal of a section of the root when there is no vascular compression or there may be diffculties in mobilizing the artery. Deliberate Bruising of the nerve in addition to decompression is also recommended [73].

Literature shows that MVD can be done in any age group. Both Resnick et al. and Roski et al. concluded that MVD can be done with good outcomes in the paediatric population [74, 75]. It is also unique that in the paediatric population, venous compression is more common than arterial.

The long-term outcome of MVD for TN suggests 87–98% have immediate pain relief but this is reduced slightly to

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 26.4** Craniotomy access showing a retracted and a cerebellar artery resting on the nerve. A piece of Tefon to be placed between the vessel and the nerve

75–80% in a 1–2 year review [76–82]. This proportion of patients with pain relief further reduced to 58–64% this is also associated with 4–12% of recurrence.

Several studies showed that the outcome of MVD is better with an arterial compression compared to venous [77, 79, 83]. Lee et al. showed a recurrence rate of 31% when there is TN due to venous compression and mostly recurred within the frst 12 months [83]. Literature shows that there are poor outcomes on patients who have had previous neurosablative surgery, but this is not substantiated by other studies [76, 84, 85]. Review of literature in the management of recurrence following MVD in TN did not provide a general consensus but suggested re-exploration and neuroablative procedures [86–88]. A good quality imaging system may enable the surgeon to pinpoint the reason for the recurrence and choose an appropriate remedial surgical intervention.

In terms of the outcomes, complication rates seem to be minimal with an experienced neurosurgical team with innovations. Although a rate of 0.2–1% mortality is shown in the earlier literature, two large studies with a patient population of 444 [79] and 1995 [52] showed 0% mortality. A recent retrospective study listed other complications such as cerebellar injury (0.45%) 8th cranial nerve injury (0.8%) and CSF leak (1.85%) [52].

Although this study showed low complication rates, other centres reported higher complication rates [80, 81]. This wide range in the outcomes is likely due to the experience of the surgical team and their advanced perioperative monitoring systems.

Despite the increasing popularity of MVD, its advantage over the neuroablative procedures continues to be debated at various levels [22, 89]. In the absence of well-structured clinical studies, varying interventions will be preferred based on the individual centre experience.

#### **26.8.2.2 Gamma Knife Radiosurgery (GKRS)**

In the 1950s, the term and the concept of radiosurgery and Gamma Knife were introduced by Lars Leksell. GKRS is used to treat various benign and malignant brain tumours and also various non-neoplastic conditions such as vascular malformations without an open intracranial surgical access. For the next few decades, GKRS is evolved with technology as the precision targeting has improved [90]. The 'Gamma Knife' technique was based on the fact that radiation may block the conduction of excessive sensory information responsible for triggering the pain episodes [91]. This would affect the radiosurgery targets with no signifcant change outside the target nerve, with the myelin sheath being primarily affected by radiosurgery [92]. It is indicated in typical or atypical TN, with or without vascular compression, failed MVD, TN patients in MS and patients with signifcant medical comorbidities.

This procedure [90–92] is done under local anaesthetic with or without sedation. Once the patient is supine under the collimator head, local anaesthetic is used to secure the stereotactic frame to the patient's head. MRI is then performed to locate the trigeminal nerve. Gamma knife is made up of 201 intercepting beams of gamma radiation with a dose of 70–100 Gy, and it is targeted at REZ of trigeminal nerve. Radiosurgery can be done with or without frame-based method, with MRI or computerized tomography (CT) planning when there is contraindication to MRI.

GKRS can also be given using one or two isocenters/target areas and targeting radiosurgery posteriorly at dorsal REZ or anteriorly in retrogasserian zone. Lower dosages to the root can be associated with fewer side effects, whereas higher dosages provide better pain control with less risk of recurrence but more side effects such as facial numbness. The benefts and risks of a higher dose must be carefully discussed with patients since bothersome facial numbness may be an acceptable option for patients with severe pain.

Two studies showed that approximately it takes a month for pain relief [91]. One of them is a multicentre study of 50 patients with a median follow-up of 18 months, which showed the results of 58% pain free and 36% had signifcant pain relief with a 6% failure rate.

However, when recurrence is evident after GKRS, repeat GKRS provides a similar rate of pain relief as the frst procedure. The best responses are observed when there is good pain control after frst procedure, with new sensory dysfunction and in single division nerve distribution typical TN.

#### **26.8.2.3 Percutaneous Balloon Compression (PBC)**

PBC was described by Mullen in 1980 [93]. It relieves TN pain by injuring the large myelinated fbres involved in the sensory trigger. It is especially useful in managing TN with frst division involvement as it selectively spares small myelinated fbres, which mediate the corneal/blink refex. It gained its role in management of TN due to its low cost and simplicity.

The procedure is performed under a short general anaesthetic, with a fuoroscopic control. A 14-gauge cannula is inserted into foramen ovale but does not pass beyond. A negative cerebrospinal fuid confrms it further. A catheter advanced through the needle, and balloon infated slowly up to a pressure of 1.3–1.6 atm. Balloon can also be infated with 0.5–1.0 ml of contrast dye until it occupies Meckel's cave, and radiographic confrmation of its position is achieved. Up to 6 min of duration of compression is achieved. Typically, patients awaken with a mild subjective sensory loss with immediate pain relief up to 80–90% [94, 95]. This subjective numbness resolves in few weeks.

PBC is most helpful when pain involves multiple divisions including the frst division, patients with MS, signifcant comorbidities and failed MVD.

#### **26.8.2.4 Radiofrequency Thermocoagulation (RFTC)**

Failures and complications in failing to control the spread of alcohol in ganglionolysis led to thermocoagulation of the Gasserian ganglion. This procedure thermocoagulates the ganglion at temperatures above 65 °C, which selectively ablates the Aδ and C pain fbres [96, 97].

The procedure is carried out under a short-intermittent general anaesthesia either under fuoroscopic control or radiologically guided. Patients are awake for the part of the procedure to ensure correct positioning of the needle. The radiofrequency needle with a stylet is introduced through the foramen ovale into Meckel's cave using bony landmarks. Transient bradycardia may occur at this juncture. Once the needle position at the trigeminal rootlet is confrmed by fuoroscopy and radiographs, the stylet can be removed to introduce the electrocoagulation needle. The patient is awakened, and the stimulation of the nerve root can be tested. A mapping of the paraesthesia is carried out to the trigger zones of the neuralgia. Then, the patient is anaesthetized again for thermocoagulation, which is achieved with 0.2–1 V. The same procedure is repeated for 45–90s cycles at temperatures of 60–90 °C. After each episode of thermocoagulation, the patient is awakened and the sensory mapping is repeated again [19].

#### **26.8.2.5 Glycerol Rhizotomy**

This procedure was a chance fnding by Håkansson and colleagues whilst working on stereotactic gamma radiation for TN. They used glycerol mixed with tantalum dust as a radio-opaque marker to visualize the trigeminal cistern and discovered that it also abolished pain. They published the frst series of 75 patients with a mean follow-up of 18 months [98].

This procedure is done under local anaesthesia with sedation. Similar to other percutaneous in the treatment of TN, the aim is to safely place the needle at the gasserian ganglion [99]. The advantage of being done awake allows the patient to sit up, and a small dose of sterile glycerol is injected in small increments. Up to a total of 0.1–0.4 ml can be used based on the number of divisions involved. Patients remain seated for up to 2 h to allow glycerol to reach the intended root.

This method is well tolerated with negligible mortality. Commonly reported complications are meningitis, cranial nerve palsies, local haematomas, reactivation of herpes labialis and permanent masseter weakness [100].

#### **26.9 Peripheral Nerve Procedures**

#### **26.9.1 Infraorbital Neurectomy**

Peripheral neurectomies are a safe and cost-effective option for patients with medical co-morbidities, elderly and for population where there is lack of highly skilled neurosurgical centres. Pain relief can be lasting from 15 to 24 months. Loss of sensation and recurrences are associated with peripheral neurectomy. These are carried out by oral and maxillofacial surgeons, and it is under reported to evaluate its benefts over central neurosurgical interventions.

Access to infraorbital nerve is gained through a maxillary vestibular approach. The infraorbital foramen is identifed as it is exiting foramen and the nerve is released from the foramen by raising the periosteum around it. Care should be taken as to ensure that there is no 'pull' to trunk of the nerve from the infraorbital canal. Reeling of the nerve is also a common practice, but sectioning of the nerve is done to eliminate the touch sensation, and there is no need to remove the infraorbital canal portion of the nerve.

The nerve is then sectioned using diathermy to have a bloodless feld and nerve branches on the soft tissue side may be closed over by releasing the surrounding periosteum to avoid regeneration. Similarly, infraorbital canal can be obturated with bone wax or chips of the bone carved around the canal.

Khanna and Galinde [101] published their successful experience of 118 patients with 75% pain relief at a 1–5 year follow-up.

Oturi et al. published their 7 years follow-up series comparing alcohol block, neurectomy and thermocoagulation. They have found that up to 78% had recurrence with the neurectomy cohort, and sadly, one of half of it recurred within a month. They reported the complications rate under 10% (dysesthesia and eye problems) on thermocoagulation and alcohol ganglionolysis patients [102].

#### **26.9.2 Inferior Alveolar Nerve or Mental Nerve Neurectomy**

Ali FM et al. [103] suggest peripheral neurectomy in a rural set-up where there is a lack of highly trained and equipped neurosurgical facilities. It is an effective option for elderly patients and who are reluctant for opting for neurosurgical intervention.

#### **26.9.2.1 Inferior Alveolar Neurectomy via Ginwala's Access** [103] (Video 26.1)

This procedure is done under local anaesthesia, with access gained to the medial aspect of the ramus using an inverted Y-shaped incision. Once the incision is made, the mucoperiosteal fap is raised along the anterior aspect of the ramus. The tendon of the temporalis and the medial pterygoid muscle is raised off the bone for access to the lingula and once the inferior alveolar nerve is dissected free off the surrounding tissues, the neurovascular bundle is clamped and cut below the clamp by electrocoagulation to achieve haemostasis. Following this, a separate buccal sulcus incision is made to identify the mental foramen and the end of inferior vascular bundle is identifed and dissected off the surrounding tissues. The bundle is then clamped and sectioned to avulse the neurovascular bundle from the canal.

Based on the available literature, there is a role for peripheral neurectomy in selective cases where other treatments have failed, and in patients with comorbidities and where there is reluctancy of either clinician or the patient to opt for neurosurgical procedures. However, it is diffcult to conclude its role as a primary interventional procedure.

#### **26.9.3 Cryotherapy**

Peripheral procedures in the management of TN result in permanent sensory loss with the aim of achieving pain free results, and therefore, alternative forms were sought. Cryofreezing is performed on the surgically exposed nerve endings with temperatures of −50 to −70 °C [104]. Literature shows that this procedure is well tolerated by the patients; however, the results are sub-optimal. In a study published in 1988, 145 patients underwent 348 sessions of which 56% had more than one session. The pain-free effect lasted less than 6 months in one half of patients, and at 12 months, only 27% were pain-free [105]. It is also important to note that 61% of the patients remained on their previous medications. The treatment it is well tolerated by the patients and were willing to undergo repeated cryofreezing and the distinct advantage is that the nerve damage is reversible. It is likely that adjacent nerve branch reconnecting is the reason for the recurrence of the pain. Although the sensation is preserved and nerve injury is reversible, its outcomes fall short of other peripheral procedures. It is reported that 4% of the patients developed post-operative infections warranting antibiotic therapy and about 40% had suffered, some from pain ranging from burning sensation, pins and needles to symptoms such as a dull ache [105].

In summary, despite patient outcomes with this procedure and preserved sensation, there is little evidence to support this procedure in the role of management of TN where other surgical procedures are available.

#### **26.9.4 Alcohol Block**

Percutaneous ganglionic ganglionic blocks and peripheral blocks have been used since the 1930s. Direct deposition of alcohol into the affected nerve peripheral branch causes chemical ablation of the nerve. Essentially, alcohol causes destruction of nerve fbres. It can seep into the adjacent tissues and cause necrosis, resulting in pain and local oedema. With a high-risk recurrence of pain and with a moderate risk of developing dysesthesia, its use is restricted only in the elderly or patients with comorbidities or those who are reluctant to undergo extensive neurosurgical procedures.

An injection of 0.5–1.0 ml of absolute alcohol is injected directly into the affected nerve bundle under local anaesthesia and injections have to be placed accurately to avoid dissipation, which may result in local damage. Utmost care must be taken to avoid intravascular injections and not to inject into the subcutaneous tissues [106].

The duration of pain relief varies from 6 to 24 months, and there is variation with different peripheral branches. Only a short pain relief with third division is observed compared to the second with a longer duration of pain relief with in the frst division [106].

#### **26.9.5 Other Peripheral Procedures**

Other peripheral neurolysis procedures seen in the literature are radiofrequency coagulation and chemical neurolysis with glycerol, phenol, mixture of lignocaine with streptomycin and high concentration of tetracaine. Evidence in the literature fails to support their true effcacy and long-term benefts.

#### **26.10 Conclusion**

TN is the most severe type of pain humans ever face for an innocuous touch without any force, and it is debilitating to an extent that it was described historically as "suicide disease" until the development of the medications and various surgical procedures in the 1950s.

As an OMF surgeon, obtaining a good clinical history is to rule out other potential pathologys including dental focus. Patients may be initially present to a primary care dentist or a physician with facial pain, and they should be aware of the medical management and the secondary care team (oral medicine specialists, OMFS and neurologists) involved to deliver the appropriate course of action. Usually, only those who are refractory to the drug therapy or unacceptable drug-related side effects will be escalated further to tertiary care for the consideration of complex central surgical procedure.

Peripheral surgical procedures are suitable for those who are unable or unwilling to undergo complex and expensive neurosurgical procedures. Peripheral procedures are safe with minimal morbidity and almost no mortality; however, there is a lack of evidence to show the recurrence rate and associated long-term complications.

The management of TN patients should be carried out in a multidisciplinary setting to allow the patients to choose the best-suited option for them. It is also important to set up selfhelp groups to enable them to share knowledge and information for themselves and their family members for the best possible outcomes.

#### **References**


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**Part XI**

**Benign Pathologies of the Oral and Maxillofacial Region**

## **Learning Targets**


#### **27.1 Introduction**

A cyst is essentially an enclosed sac formed by the cluster of cells, which group together. The unique characteristic of a cyst is that the cells that form the outer covering of the sac are abnormal from the surrounding normal cells of that specifc region. There are various categories of cysts, which can occur almost anywhere within the human body's hard and soft tissues, and their occurrences are very common. They vary in size from tiny microscopic to huge macroscopic varieties, and the large cysts can displace the adjoining normal anatomical structures.

Once formed, sometimes, a cyst may resolve on its own, but in most cases, it keeps growing and needs surgical intervention depending on its type and location. Cysts are usually nonaggressive, but certain groups of cysts show aggressive behavior. The cysts of the oral and maxillofacial region are the commonest pathological entities. Historically, mummifed specimens in Egypt (400 BC to 2800 BC) showed the presence of cysts [1].

N. Malik (\*)

### **27.2 Defnition**

A cyst is explicitly defned as "A pathological (uni- or multilocular) sac that may or may not be lined by an epithelium and flled with a fuid, semifuid, or gaseous contents and not created by the accumulation of pus" [1, 2].

### **27.3 General Histopathological Common Components of a Cyst**

Cysts can be found in the facial bones as well as in the soft tissues of the orofacial region.

Cysts lined by an epithelium are more common in both jawbones than any other regions of the body because of great many epithelial cell rests present in close proximity to the developing jaw bones, and they are called True Cysts, e.g., radicular cyst, dentigerous cysts, etc.

Pseudocysts do not have an epithelial lining, e.g., solitary bone cysts, Cysts of maxillary antrum, etc. [1] (Fig. 27.1).

A cyst is a tissue-space occupying lesion/sac with a cavity in the center known as a Lumen. There is an outer fbrous connective tissue wall that separates the cyst from surrounding normal tissues. On the inner aspect of this wall, there is a cystic lining of epithelium, mostly made up of stratifed squamous epithelium (Fig. 27.2). In some cases, there can be lining other than squamous epithelium.

### **27.4 Etiopathogenesis**

The etiopathogenesis of orofacial cysts basically originates from the remnants of the complex processes of embryonic tissue responsible for jaw and dental development. Such a conversion does not occur in any other part of the body.

All True Cysts have their genesis from the epithelial remnants along with strong proliferative impetus and capability for bone remodeling. Odontogenic cysts are derived from

## **Cysts of the "Oro-Maxillofacial Region"**

**27**

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 549

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_27

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_27) contains supplementary material, which is available to authorized users.

Department of Oral and Maxillofacial Surgery, Krishna Institute of Medical Sciences "Deemed to be University", Karad, Maharashtra, India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 27.1** Histological picture of a true (**a**) and pseudocyst (**b**)

Various Histopathological Components of A Cyst

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 27.2** General broad histopathological characteristic components of a Cyst; Epithelial lining-various types of epithelium can line a cyst

remnants of odontogenic epithelium of stomodeum, and infammatory cysts are derived from infective process (Table 27.1).

Pathogenesis of a cyst is mainly divided into three stages:

(1) Cyst Initiation, (2) Cyst Formation, and (3) Cyst enlargement or expansion

1. *Cyst Initiation*—unknown stimulus promotes the rapid increase of epithelial rest cells via cytokine synthesis. The factors, which are suggested to be responsible for cyst initiation phase, are mainly genetics, loss of immunological surveillance, infammatory mediators, or some local fac-



tors like decreased oxygen tension along with increased CO2 tension.

The residual epithelial cells (Table 27.1) are implicated to initiate the process of cyst formation. Initiation is followed by the rapid growth of the epithelial cells and the development of a cystic lesion.

2. *Cyst Formation*—Nutritional defciency theory

After initiation, proliferating epithelial cells form a mass inside the sac and the innermost central cells become deprived of nutrients/blood supply, as they are far from the source of nutrients. The innermost cells do not get adequate blood supply, and so there is an ischemic liquefactive necrosis in the center, leading to a cavity formation, which is surrounded by growing epithelial cells. Enhancement in intercellular edema and acid phosphatase activity leads to the formation of microcysts, which slowly start to form a larger cyst [4].

3. *Cyst enlargement or expansion* Once formed, the cyst continues to enlarge slowly, over the months.

The process is similar for all epithelial lined cysts with some variations. Many debatable hypotheses have been put forward regarding the defnitive mechanism of cyst enlargement.

#### **27.4.1 Theories of Cyst Enlargement/ Expansion**

#### **27.4.1.1 Mural Growth & Peripheral Cell Division**

(a) Epithelial proliferation-peripheral cell division, (b) Accumulation of the contents within the lumen.

Due to Proliferation or rapid increase in the number of cells and by the active division of peripheral lining epithelial cells, surface area of cystic sac increases and the enlargement of a cyst at the circumference is noted along with the accumulation of cellular contents [4, 5].

#### **27.4.1.2 Hydrostatic Enlargement**

#### **Biomechanical Theory**

Intraluminal concentration and pressure differences between the cystic cavity and the peripheral growth surroundings infuence fuid movement into the cyst, bringing about an increase in size.

Cyst starts expanding and growing in size, with the increase in intracystic pressure due to the intake of fuids inside the cyst from the surrounding area. (The center of the cyst has higher concentration of sodium than the surrounding serum, and so it tends to absorb water.)

This increase in cyst size process is different from the true autonomous growth, which is found in tumor cells [5, 6].

Secondary proliferation of epithelial cells is, thus, a result of increased volume pressure within the cystic cavity, as a result of osmosis. An osmotic concentration gradient is created as a result of degradation and metabolic by-products, which are taken up inside the cyst.

Due to the rapid increase in the osmotic gradient, the fuid from the surrounding region diffuses in the cystic cavity, increasing internal hydrostatic pressure and thereby resulting in the expansion of the cyst (Fig. 27.3).

Cyst wall -semipermiable membrane ©Association of Oral and Maxillofacial Surgeons of India

#### **27.4.1.3 Bone Resorbing Factor**

In intraosseous cysts, resorption of the surrounding bone also increases the size of bony cavity.

#### **Biochemical and Cellular Aspects of the Cyst Proliferation**

Newer research points to the role of molecular biology in cyst proliferation, over older theories of bone loss resulting from osmotic gradient. The cystic capsule produces bone resorbing factors like prostaglandins, leukotrienes, and osteoclasts.

(A) Bone degeneration in the jaw bone is brought by Collagenase (breakdown of collagen), providing room for cysts to develop. Body's immune mechanism releases cytokines and growth factors due to the connective tissue breakdown, which contributes to the mobilization and proliferation of epithelial cells in the area.

Evidence-based studies showed that collagenase activities in cystic capsule result in bone degeneration by destruction of the collagen [6, 7].

(B) Prostaglandin theory—Bone resorption caused by metabolism of acidic matter produced in the cysts lends to the cystic growth. These are the substances produced by the cyst itself, which include Prostaglandin-2 and Interleukin-1. Along with the epithelial cell division, the cyst enlarges within the jaw bone due to bone resorption caused by Prostaglandin-induced osteoclastic activity. Bone resorption is mediated as a result of production of PGE-2 and PGE-3 by dental cysts. Prostaglandin-2 and other by-products are part of arachidonic acid metabolism [8].

The production of prostaglandin-2 can be triggered by Interleukin-1. Meghji et al. [9] summarized that odontogenic cysts produce interleukin-1, which in turn triggers the production of Prostaglandin-2, resulting in osteoclastic bone resorption and cyst enlargement. Most dental cysts demonstrate a common growth mechanism though radicular and developmental cysts may be initiated by different factors (Flow Chart 27.1).

### **27.5 Historical Evolution of the WHO Classifcation Systems**

Many researchers including WHO have tried to put forward a uniform, globally accepted nomenclatures and classifcations for the cysts of orofacial region. But still there is a continuous debate going on, and therefore, various classifcations are cited in the literature. WHO in 1992 [2] had classifed cysts into two main categories as odontogenic and nonodontogenic, with further subsets as developmental and infammatory (Flow Charts 27.2 and 27.3).

**Table 27.2** According to Shear [1], cysts of orofacial region are categorized under three major groups:


This simple classification did not include Calcifying odontogenic cyst (COC), cysts involving maxillary sinus and nonodontogenic soft tissue cysts. WHO in 2005 [10] reclassified the cysts into epithelial and nonepithelial varieties, which were further divided into odontogenic and nonodontogenic types. At this time, COC—calcifying odontogenic cyst—and Odontogenic Keratocysts (OKCs) were not considered as cystic entities, but they were listed as keratocystic odontogenic tumors— KCOT—and calcifying cystic odontogenic tumors— CCOT—respectively. The justification for this new OKC designation was the high recurrence rate and aggressive behavior along with association with mutations in PTCH gene. This reclassification led to a lot of confusion, and it was not accepted by many. But in 2017, the peer group of WHO did not think that there was sufficient affirmation for classifying both OKC and COC as neoplasms. Therefore, in 2017 again, both these lesions were put back in the cyst category [11].

Among so many classifcations, Shear (2007) has suggested a comprehensive classifcation of cysts with good understanding of cystic lesions of mouth, face, and neck region [1] (Table 27.2).

The cysts of the jaws are divided into those that are:

	- A. Epithelial-lined cysts
		- 1. Developmental origin
			- (a) Odontogenic Developmental cysts
				- (i) Odontogenic keratocyst
				- (ii) Dentigerous cyst
				- (iii) Developmental lateral periodontal cyst
				- (iv) Gingival cyst of infants
				- (v) Eruption cyst
				- (vi) Gingival cyst of adults
				- (vii) Glandular odontogenic cyst
				- (viii) Calcifying odontogenic cyst
				- (ix) Botryoid odontogenic cyst
			- (b) Nonodontogenic Developmental cysts
				- (i) Midpalatalraphé cyst of infants
				- (ii) Nasolabial cyst
				- (iii) Nasopalatine duct cyst
		- 2. Odontogenic Infammatory origin
			- (i) Radicular cyst, apical, and lateral
			- (ii) Paradental cyst and juvenile paradental cyst
			- (iii) Residual cyst
			- (iv) Infammatory collateral cyst
	- B. Nonepithelial-lined pseudocysts
		- (i) Solitary bone cyst
		- (ii) Aneurysmal bone cyst
	- (i) Retention cyst
	- (ii) Mucocele
	- (i) Dermoid and epidermoid cysts
	- (ii) Thyroglossal duct cyst
	- (iii) Lymphoepithelial (branchial) cyst
	- (iv) Anterior median lingual cyst (intralingual cyst of foregut origin)
	- (v) Nasopharyngeal cyst
	- (vi) Oral cysts with gastric or intestinal epithelium (oral alimentary tract cyst)
	- (vii) Cystic hygroma
	- (viii) Thymic cyst

#### **27.6 Prevalence of Cysts**

Quite a large number of studies are conducted on jaw cysts, but detailed information on demographic profles in different populations is limited and most have focused on odontogenic cysts [12, 13] (Box 27.1 and Fig. 27.4).

#### **Box 27.1 Prevalence of Dento-orofacial Cysts**

*Incidence*:


*Age*: Range from the 1st to 9th decades. Peak incidence is seen between 21 and 30 years of age.

*Sex*: More prevalent in males, with a male to female ratio of 1.4:1 [12, 13]

*Site*: Review of literature suggests mandibular preponderance and may imply a higher tendency for activation of cell rests to cystic degeneration in the mandible.

#### **Box 27.2 Diagnosis of the Cystic Lesion Can Be Arrived by the Following Steps**


#### **Box 27.3 History**

History: Duration of the complaints/progress is also important. History of pain, loose teeth, occlusion change, intraoral/extraoral swelling/discharge, or sinus track, missing teeth, and delayed eruption of teeth should be noted.

#### **27.7 General Key Attributes Regarding an Oro-maxillo-Facial Cyst-Signs & Symptoms** (Boxes 27.2 and 27.3)

Signs and symptoms of a cyst depend on its size and site. Small cysts are detected as an incidental fnding during routine radiographic examination. Large cyst after enlargement can be noticed frst by the patient himself, or there can be facial disfgurement noticed by others. Generally, cysts are symptoms free, unless they get infected secondarily.

If the cyst has not enlarged beyond its normal anatomical boundaries of the jaw bone, then its lump cannot be palpated intraorally or extraorally. The majority of cysts expand very slowly, and the surrounding bone gets time to form fresh subperiosteal new bony layer around the lesion, which isolates the lesion.

#### **On Palpation**

1. During early stage, smooth, bony hard, and painless prominence can be felt.

cysts

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bone cyst

Eruption cyst

2. Later on "eggshell crackling" can be felt at the thinned out less mineralised *cortex.*

cavity


A cyst may become secondarily infected, and pus discharge may be seen into the oral cavity via a sinus tract. Examination of the sinus track and discharge from sinus track should be checked for cholesterol crystals or pus. Salty, sweet, or unpleasant taste of the discharge is noted.

Residual cyst

Nasolabial cyst

At this stage, patient may complain of pain. Loosening of adjacent teeth or displacement of the teeth out of their normal arch alignment can happen. Very rarely, depending on the variety of cyst, as it enlarges to an enormous size, it may resorb adjoining teeth/roots, as well as bone, and may end up in pathological fracture of the jaw bone. As most cysts enlarge at a slow pace, and even in the large lesions, the inferior alveolar canal usually gets displaced and there will be no altered sensation (anesthesia or paraesthesia). Paraesthesia and/or anesthesia of the lower lip can exist in aggressive or acutely infected cysts. Percussion of involved teeth will produce a dull or hollow sound. Usually, highpitched sound is obtained on the uninvolved teeth. Edentulous patient will complain of ill-ftting denture due to the bulge. Periapical cysts are always seen in relation to one or more nonvital teeth. A large maxillary anterior region cyst may cause distortion of nostril shape and show nasal congestion. Diagnosis can vary as per the site of the lesion,

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 27.5** Clinical examination: extraoral inspection; (**a**) extraoral swelling on the right cheek area, (**b**) head position for inspection of swelling and comparison with normal side, and (**c**) intraoral examina-

age of the patient, clinical, radiological, and histopathological examination (Fig. 27.5).

#### **27.7.1 Vitality Test of the Involved Teeth in the Lesion**

In cysts other than radicular cysts or infammatory periodontal cyst, there is no compromise in blood supply of the teeth, and so teeth vitality is preserved. Vital teeth are associated with odontogenic keratocyst, solitary bone cyst, lateral periodontal cyst, etc. In infammatory cysts, the vitality of all involved and adjoining teeth should be checked.

#### **27.7.2 Radiographic Examination**

Radiographic picture of a cyst is not always pathognomonic. It will depend not only on cyst category, but also the variants related to its duration, location, and degree of expansion and the presence or absence of infection. When the patient is referred for X-rays, the type of flm used will depend on the tion showing obvious bulge in right buccal vestibule. *(Courtesy Dr, Kumar Nilesh, SDS, Karad)*

size of a lesion. Dental panoramic or maxillofacial Cone Beam CT provides good imaging for most of these cystic lesions. They help to defne site, size, extent, and marginal outline of the lesion.

Intraoral flm: For smaller lesions, minimum of two flms are taken at right angles to one another. Periapical and occlusal views may be taken.

Extraoral flm-used for larger lesions. Panoramic/ Orthopantograms, Lateral oblique views, and Water's view may be taken.

Patient may be referred for CT scan or MRI in cases of extensive aggressive lesion or recurrent lesions to know the exact expanse, proximity to the important vital structures/ adjacent anatomical structures, perforations, and multilobulated/multicystic character. If there is suspicious extraosseous lesion with soft tissue extension or malignancy, then it is also indicated. Postoperative imaging helps to assess the rate of regression and bone regeneration.

#### **27.7.2.1 General Radiographic Picture**

1. Radiographically, intrabony cysts, small or large, form sharply defned unilocular or multilocular radiolucency with or without cortication.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 27.6** Different radiological picture of the cystic lesions as per the types: (**a**) replacement type (cyst in place of third molar), (**b**) envelopmental type (cyst enveloping lower third molar), (**c**) extraneous type

(ascending ramus cyst away from teeth), and (**d**) collateral type (adjacent to the roots of the teeth)


#### **27.7.2.2 Radiological Classifcation of Jaw Cysts (Shear)** [1]


### **27.7.3 Aspiration**

The orofacial cyst contains fuid in its cystic cavity, which varies in consistency, color, and protein content, and helps in differentiating and arriving at a provisional diagnosis based on these observations. These fndings should be remembered to be able to diagnose any cyst, which may be encountered in the clinical practice. An aspiration biopsy of a cyst is the norm for initial diagnosis of all cysts.


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 27.7** Aspirated cystic fuid; (**a**) aspiration from infected radicular cyst, (**b**) aspiration from infected keratocyst

#### **27.7.4 Cystic Fluids**

Cystic contents are different ranging from clear yellow fuid to a creamy or cheese like semisolid liquid. The content can be examined for its color, consistency and for the existence shimmering cholesterol clefts or crystals (microscopic examination of cholesterol crystal shows an envelope with cut-corner appearance). Electron microscopic examination reveals the presence of various protein fractions like alpha and beta globulin , albumin, fecks of keratin, as well as total protein content along with inorganic phosphates [14] (Table 27.3).

#### **27.7.4.1 Biochemical Analysis of the Cystic Fluid**

Toller has opined that by an active cellular transport mechanism, the proteins are drawn into the cystic fuid by immunoglobulin (Ig) producing cells. Estimation of IgA, IgG, and IgM levels in cystic fuid can be done quantitatively [15]. Smith et al. [16] concluded in their study that the most of the cystic fuids show the presence of proteins with higher molecular weight. This is due to the fact that the semipermeable intraepithelial channels facilitate the passage of lactoferrin into the cystic lumen.

The cystic fuid, which is collected via aspiration biopsy, can be biochemically analyzed for their protein content estimation by Cellulose acetate membrane (CAM) electrophoresis. First, the cystic fuid is transferred to the centrifuge machine for the removal cell debris and deposits at 2000 rev/ min for 5 min.

Since electrophoresis studies the movement of charged particles through an electrolyte, which is subjected to an electric feld, and it separates different proteins as per their physical properties, the fuid free of debris is then studied qualitatively and quantitatively. The protein mixture is applied to the end of the CAM strip. Scanning of these impregnated CAM strips can be carried out using a densitometer for the quantitative estimation of protein fractions.


#### **Table 27.3** Various cystic lesions and their aspirates

#### **27.7.5 Biopsy**

Incisional (for large lesions) or excisional (for small lesions) biopsy and histopathological examination of the specimen is the gold standard to arrive at fnal diagnosis.

#### **27.8 Various Surgical Treatment Modalities for Cystic Lesion**

With all the investigation results in hand, the surgeon will have a clear idea of the type, the location, extent, and behavior of the lesion. A fnal diagnosis is then obtained, and a suitable surgical line of treatment is decided upon (Boxes 27.4, 27.5, 27.6, 27.7, 27.8, 27.9, and 27.10).

#### **Box 27.4 Clinical Tips**

Incisional Biopsy: For large lesions, a "representative" section of the lesion is incised with the help of a scalpel along with the normal tissue and sent for histopathological evaluation. An elliptical, wedge-shaped tissue is obtained with the "V" of the wedge converging into the deeper tissues. The depth of the biopsy should be enough to obtain a representative area of the lesion.

Excisional Biopsy: It is a combination of diagnostic and curative procedure and is suitably smaller for lesions <1 cm. In these cases, the entire lesion is excised in toto at the same sitting and sent for histopathological examination.

#### **Box 27.5 Reasons for the Defnitive Treatment**


#### **Box 27.6 Goals of Surgery**


#### **Box 27.7 Factors for the Choice of Optimum Surgical Strategy/Treatment**

*Patient factors & lesion characteristics*


#### **Box 27.8 Conservative Surgical Treatment**


#### **Box 27.9 Enucleation with Adjunctive Modalities to Eliminate the Microscopic Pathologies**


#### **Box 27.10 Aggressive Surgical Treatment**


#### **27.8.1 Conventional Surgical Options**

The objective of the choosing any particular surgical method is to minimize patient morbidity and reduce the recurrence rate. Surgical procedures for treating cystic lesions are often put into two categories; conservative or aggressive (Boxes 27.8, 27.9, and 27.10).

*Decompression and marsupialisation (cystotomy)*: Partsch I operation of the cysts is presumably the earliest treatment. Enucleation or cystectomy with primary closure is also known as Partsch II procedure (Partsch 1892, 1910) [17].

*Decompression, marsupialisation*: both methods achieve evacuation of the cystic contents by creating a surgical opening in the cystic wall. These procedures preserve the continuity of the cystic lesion with the oral/nasal cavity or maxillary sinus.

#### **27.8.1.1 Decompression**

Decompression of a cyst is achieved by a minor surgical procedure, which decreases the intracystic hydrostatic pressure, which is responsible for cyst expansion. Subsequently, decompression allows for the bone remodeling and bone fll.

Decompression can be achieved under L.A. by creating a small opening in the cystic wall and keeping it patent with a surgical drain. Acrylic tubes, Luer syringes, polyethylene tubes, nasopharyngeal airways, or nasal cannula or intravenous tubes have been used by fxing them with sutures or wires to keep the opening in the cyst patent, through which the cystic lumen is fushed twice/thrice everyday with saline/ antiseptic wash.

Cysts of the lower jaw are normally evacuated through opening into the oral cavity, and maxillary cysts can be drained either into the oral cavity, the maxillary sinus or nasal cavity [17] (Fig. 27.8).

#### **27.8.1.2 Marsupialization**

It is a surgical procedure, whereby a cystic sac is modifed or deroofed to convert it into a pouch. This results in a selfsustaining stoma/opening or outlet, which in turn reduces intracystic hydrostatic pressure. It is basically a surgical externalization of the cystic cavity by creating an opening in the superfcial aspect of the cyst. The resected portion is sent for histopatholgical study. The remainder borders of the cystic wall are then sutured to the surrounding edges of the oral mucosa, thus converting an enclosed sac, into an open pouch, exposing the cystic lining or epithelium to the oral environment. This procedure decreases the volume and size of the lesion and promotes the speedy healing and new bone formation. This option is more precise compared to the decompression method. Marsupialization may be used as a solo treatment regime for a cyst or as a prior step to fnal second stage enucleation [17].

*Surgical Procedure* In Marsupialization, after locally anesthetizing the buccal/labial area, an oval/elliptical incision is taken to make a surgical window spanning 1 cm into a cyst; the window cover consisting of oral mucosa, thinned out bony cortex and cystic lining, is removed, and the boundaries of the cystic lining around the surgical opening are sutured to the surrounding oral mucosa. In the case of a thick bony cover over a cyst, an inverted U-shaped incision is planned with a wider base in the buccal sulcus, mucoperiosteal fap is refected, and bony window is removed cautiously with burs or rongeurs. The excised tissue of the window created must be subjected to histopathological study. The contents of the cyst are sucked out, and the residual lining of the cyst is inspected. The remainder cystic cavity is irrigated thoroughly to lavage any residual debris. The residual cystic cavity is inspected carefully for any abnormal fndings like ulcerative lesions or possible dysplastic/neoplastic areas.The cystic cavity is then packed with ribbon gauze strip soaked with tincture of benzoin or iodoform/white head's varnish or paraffn, or an antibiotic ointment, or bismuth iodine paraffn paste-BIPP, with its end protruding through the opening.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 27.8** Decompression of a cystic lesion by creating a small opening and keeping it patent by inserting a drain. (**a**, **b**) Decompression through oral cavity, (**c**) maxillary sinus, (**d**) nasal cavity

This packed gauze strip is left in situ for 2 weeks, until the line of junction between the cystic lining and oral mucosa is healed. After it is removed from the cystic cavity, the patient needs to irrigate/gargle with antiseptic mouthwash frequently in a day to prevent food accumulation. The fushing has to be continued for many following months, until the bone fll and complete healing is noticed.

Later on, acrylic plate or plug/obturator can be prepared to protect the healing cavity and used until it gets obliterated over a period of time, but as the healing progresses, the plug needs periodic adjustments (Table 27.4).

#### **27.8.2 Modifcation of Marsupialization-Waldron's Method—Two-Staged Procedure** [17]

Usually, once the cystic lesion regresses in size after initial marsupialization procedure, enucleation is carried out as a second stage surgery.

The larger or inaccessible cyst is initially marsupialized, and bony healing in progress is observed. As the cystic cavity decreases to a relatively small size, then complete surgical removal is possible by enucleation. The proper time for secondary enucleation is when bone covers adjoining vital structures. This protective shield of new bone prevents their injury during secondary enucleation, also provides adequate strength to the basal jaw bone, and prevents pathological fracture.

In a cyst associated with developing tooth bud, as soon as the tooth erupts into the dental arch alignment, there may not be any residual cystic lining left to enucleate. Decompression and/or marsupialization with less morbidity and preservation of adjoining vital structures has a good rate of success over many other aggressive treatments (Figs. 27.9 and 27.10).

#### **27.8.3 Enucleation or Cystectomy or Partsch II**  (Videos 27.1 and 27.2)

*Enucleation or Cystectomy or Partsch II* with and without adjunct procedures has been validated as the most appropriate surgical modality for almost all cysts of the orofacial region, with various adjunct procedures as deemed ft for individual case.

To enucleate is "complete removal or excision in toto from its envelope without rupture." With this, no bone, other than required for surgically accessing the lesion, is removed.

It is the most versatile treatment modality, and many researchers have said that the surgical enucleation of a cyst in one piece has been known to reduce the rate of recurrence.

An enucleation procedure is possible because of the presence of a fbrous connective tissue layer in between the epi**Table 27.4** Indications, advantages & disadvantages of decompression & marsupialization


thelial lining of a cyst and cystic cavity bony wall. This layer acts as a cleavage point for separating the cystic lining from the jaw bone and makes surgical procedure of enucleation easy, as we carry out stripping of periosteal layer from the jaw bone. The surgical cavity gets flled with the blood clot and eventually gets organized into bone formation.

#### **27.8.3.1 Surgical Procedure**

The small cysts can be treated with local anesthesia, but larger cysts need to be treated under general anesthesia. As per the size and site of the lesion, the mucoperiosteal fap is designed, following the right surgical principles. If the bone over the lesion is thinned out, access can be gained by removal of the cortical bone by rongeurs. But if the bony cortex overlying the access area is hard and thick, then the osseous window is created by using rotary burs.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 27.9** Diagrammatic representation of Marsupialization procedure; (**a**) creation of opening on the buccal side of a cyst, (**b**) suturing remaining cystic lining to oral mucosa, (**c**) fnal suturing to keep the

After complete enucleation procedure is over, the entire cavity is inspected for proximity of the adjoining vital structures and for the remnants of the pathological tissues.. In large extensive cysts, usually the neurovascular bundle is pushed to one side by the slowly growing lesion, and in these cases, atraumatic enucleation should be carried out. Irrigation and cleaning of the entire bony cavity with saline will assist in visualising/inspecting it. The roughened bony edges of the cavity are then smoothened with a fle or rotary bur before fnal suturing.

Cysts that include tooth roots or certain areas of the jaws, which are surgically inaccessible, require thorough curettage, in order to remove fragile cystic lining fragments. If devitalization of the teeth is brought about during enucleation, then the affected teeth should be treated with root canal fllings.

*Clinical Tips*: If the patient is young and the lesion is involving multiple anterior teeth, the teeth can be retained after root canal treatment and apicectomy, provided thorough inter-radicular curettage by using small periodontal instruments.

If the teeth show a great degree of mobility and in the case of recurrent lesion, they should be extracted.

Enucleation of a cyst is followed by watertight suturing over the sound bone. To achieve this, sometimes, mobilization of the soft tissue faps with advancement is required. If complete surgical suturing is not possible, then the defect should be packed with stripped ribbon gauze soaked with an antibiotic ointment or BIPP/White head's varnish. Frequent cystic cavity open into oral cavity, and (**d**) diagrammatic representation of Marsupialization procedure

change of this packing is advocated after irrigating the cavity, until new granulation tissue has flled up the cavity and complete epithelisation of the wound has taken place (Fig. 27.11).

#### **27.8.3.2 Enucleation Along with the Adjunct Procedures**

Enucleation with different adjuncts has been carried out since many years.

#### A. *Enucleation with Peripheral Ostectomy*

It is basically used as an additional adjunctive step for peripheral bone trimming for avoiding resection, as almost all hypotheses for recurrence point out toward the possibility of leaving residual pathological fragments behind, especially, in the large cyst with scalloped borders or cysts with diffcult access. Here, a greater risk of incomplete excision may exist. Adjunct procedure of peripheral ostectomy may be carried out in cases of cysts, which have high recurrence rate, e.g., Odontogenic Keratocyst. A peripheral ostectomy with rotary bur with sterile irrigation helps to remove all the microscopic residual pathological tissue. The procedure is followed to remove the lesion in one piece along with an enveloping border of bone, and hence, the possibility of iatrogenic rupture of the cystic capsule or leaving its fragments behind is greatly reduced. A minimum 2–5 mm bony margin inclusion for peripheral ostectomy is supposed to be adequate. In the case of thin inferior border of mandible, reinforcement with reconstruction plate is advocated. This can also be accomplished by means of mechanical hand instruments like a sharp curette. The recurrence of the cyst can be prevented by this procedure.

**Fig. 27.10** *(CLINICAL CASE SCENARIO)*: (**a**) OPG showing the large radiolucent lesion extending in the mandibular body with impacted canine at the inferior border, (**b**) CT scan of the same patient showing multilocular radiolucent lesion with embedded canine, (**c**) a large opening was created in the anterior body mandible region, and roof of the cyst along with oral mucosa was removed along with the evacuation of

the cystic content, (**d**) healing of the wound after marsupialisation, (**e**) acrylic plate was constructed to cover the wound, (**f**) 6 months followup, lesion reducing in size, and (**g**) OPG after six months showing the reduction in size of the cyst. The patient is advised to undergo second stage surgery for enucleation and extraction of impacted canine. *Courtesy-Prof.Vidya Rattan, PGI, Chandigarh*

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 27.10** (continued)

#### B. *Enucleation and application of Carnoy solution to the bony defect*

Many a times, due to the thin, friable wall and the presence of many small satellite cysts, there is a diffculty of enucleating it in one piece. Hence, the surgical treatment is focused on eliminating all residual epithelial fragments. In order to achieve this, a mild, judiciously penetrating, and cauterizing agent like Carnoy's solution is utilized. It has a mean bone penetration depth of 1.54 mm, with an application time of 5 minutes. (Carnoy's solution's composition is 3 ml of chloroform, 6 ml of absolute ethanol, 1 ml of glacial acetic acid, and 1 g of ferric chloride) [18, 20–22]. This is adequate to bring about chemical cauterization of the residual pathologic fragments. Literature shows the use of modifed Carnoy's solution without chloroform, as it is currently listed as a carcinogenic agent.

The protocol of carrying out enucleation followed by the application of Carnoy's solution in the treatment of locally aggressive cysts, like OKCs, lowers the recurrence rate and morbidity. During the application of Carnoy's solution, the neurovascular bundle can be protected by using bone wax cover or wooden spatula or paraffn gauze.

Dashow et al. studied and compared the use of Carnoy's solution versus modifed carnoy's solution in cases of OKCs and stated that the recurrence is almost eliminated, and the results are comparable to those of the resection without carrying out the morbid surgery [22].

C. *Enucleation followed by liquid nitrogen cryotherapy* The aggressive cysts are best treated by enucleation followed by cryotherapy, using liquid nitrogen. This therapy is commonly used for the treatment of many locally aggressive jaw lesions, such as ameloblastoma, OKC, or ossifying fbroma [23]. Cryotherapy destroys the residual

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 27.11** *(CLINICAL CASE SCENARIO)* (**a**) OPG showing the presence of a dentigerous cyst in a 7 years old child, (**b**) clinical intraoral picture of the same, (**c**) refected fap to expose the underlying expanded

buccal cortex, and (**d**) enucleation of the lesion in toto. *Courtesy Dr, Kumar Nilesh, SDS, Karad*

epithelial lining cells or satellite cysts and leaves behind the inorganic bony matrix intact, which is helpful for osteoconduction. Liquid nitrogen causes bone devitalization due to direct effect/damage from ice crystal formation, which takes place in the cellular and extracellular compartments and due to the subsequent osmotic and electrolyte disturbances [23]. The routine frst step in surgery of the lesion is enucleation of a cyst, followed by cryotherapy. The adjoining tissues are then shielded by sterile wooden spatula and gauze strip, and the residual cavity is treated with liquid nitrogen spray—two swipes for 1 min each, with a 5 min thaw break between two spray freezes. After cryotherapy, it is possible to place the bone graft in the cystic cavity to strengthen the jaw bone. Finally, the wound is sutured in a watertight manner [23] (Box 27.11 and Table 27.5).

#### **Box 27.11 The Advantages and Disadvantages of Liquid Nitrogen Cryotherapy After Enucleation** *Advantages*:


#### *Disadvantages*:


#### **27.8.3.3 Enucleation Followed by Bone Grafting**

#### *Indications*


Autogenous bone grafts possess characteristic osteoconductive and osteoinductive qualities due to the presence of abundant osteoprogenitor cells. The use of Autogenous cancellous bone grafts for large defects to obliterate the cavity and stimulate osteogenesis is the gold standard, but the issue of donor site morbidity is always there. The dead space elimination after enucleation of a large defect is recommended by packing the defect with autogenous bone graft or its synthetic substitute. Calcium phosphates, α- and β-tricalcium phosphate (TCP), bioactive glasses, calcium sulfate, glass ionomers, hydroxyapatite (HA), etc. are some of the synthetic graft materials available in the market, which can be used instead of autogenous bone grafts, for filling up the defect after enucleation. The blood clot in the cystic cavity is stabilized by these synthetic grafts, thereby minimizing the postoperative infection. These synthetic grafts are also osteoconductive in nature and promote new bone formation by facilitating the migration of osteoprogenitor cells [24, 25].

**Table 27.5** Indications, advantages, & disadvantages of enucleation along with adjunct procedures


#### **27.8.4 Block Resection, With or Without Preservation of the Continuity of the Jaw**

Resection of a jaw bone can be done either as (1) marginal resection procedure or (2) segmental resection procedure. In marginal resection procedure, the lesion is smaller, which is excised in toto, and hence, it is possible to maintain the continuity of the jaw bone by preserving the portion of the uninvolved bone. In segmental resection procedure, since the lesion is extensive, the complete segment/portion of maxilla or mandible is sacrifced, and hence, continuity of the jaw bone is lost after this radical treatment. Since this procedure ends up in considerable morbidity, there is always a need for rehabilitating the patient functionally and esthetically by various reconstructive measures [26]. Many researchers felt that there is no need for aggressive therapy in the case of cystic lesions, as their management can be done by using relatively noninvasive means [26].

Blanas et al. [21] carried out a systematic review and found that following resection, there was 0% recurrence rate, but it is always associated with the high morbidity rate. Their study suggested that enucleation followed by the use of Carnoy's solution gives similar low recurrence rates, as resection, without unwarranted radical surgery. Complete resection of the mandibular/maxillary bone is considered as morbid overtreatment for large locally aggressive cysts. The only main disadvantage of a conservative treatment is prolonged therapeutic time [27].

In this chapter, we will be discussing only briefy Dentigerous and Keratocyst varieties prototypes.

#### **27.9 Dentigerous Cysts or Follicular Cysts**

*Dentigerous Cysts or Follicular Cysts*, The term dentigerous is a Latin word, literally means "tooth bearing/producing". Paget in 1853 frst coined the term "Dentigerous cyst", in this entity, there is an enclosure of the crown of a tooth, which is unerupted, and cyst is attached to the CE junction and is formed by the enlargement of its follicle [1]. There is always an association of this cyst with the crown of fully or partially impacted or submerged tooth (Fig. 27.12).

Depending on the location and extent of the cystic degeneration in relation to the crown of an unerupted tooth, the cyst can have central, lateral, or circumferential variety [28]. In central type, initially, the crown may be enclosed by a cyst symmetrically, but as it expands, crown of the mandibular third molar may be shifted to the inferior border of the mandible or

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 27.12** Formation of a dentigerous cyst

migrated high up in the ascending ramus and similarly, maxillary canine or third molar may be seen at the orbital foor or high in maxillary sinus. The lateral type will be because of expansion of cyst only on one particular side of the crown, and it will be seen in cases of partially erupted mandibular third molars. In circumferential type, the radiograph will show a radiolucency enveloping the entire tooth (Fig. 27.13).

#### **27.9.1 Diferential Diagnosis**

Hyperplastic follicle-Normal follicular space size is 2–3 mm; if it exceeds 5 mm, then dentigerous cyst should be suspected.

Differential diagnosis of unicystic ameloblastoma, an odontogenic keratocyst, Calcifed odontogenic cyst, Ameloblastic fbroma, Adenomatoid odontogenic tumor, or radicular cyst must be considered in such cases comparable to the radiographic details, but the incidence of all the above lesions is rare in the frst decade of life. Since radiographs alone cannot differentiate the above-mentioned lesions, a histopathological examination should be performed.

#### 27 Cysts of the "Oro-Maxillofacial Region"

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 27.13** Types of dentigerous cysts and their radiological picture of central, lateral, and circumferential type (**a**–**c**)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 27.14** Arrow pointing to a thin lining in dentigerous cyst resembling reduced enamel epithelium histologically

#### **27.9.2 Histology**

Thin layer of nonkeratinizing stratifed squamous epithelium lining the lumen is seen, and no rete ridges are seen. Connective tissue wall shows bundles of collagen fbers; sometimes, many odontogenic epithelial islands are seen. The cystic lumen contains thin, watery, and yellowish fuid (Fig. 27.14).

#### **27.9.3 Potential Complications of Dentigerous Cyst**


#### **27.10 Odontogenic Keratocyst**

OKC has got its name because it exhibited keratinization of cystic lining. Its lumen contains a cheesy material resembling keratin debris and clear fuid. It is a Dilemmatic, Distinctive, Odontogenic Developmental, and Intraosseous cyst of epithelial origin of Oral & maxillofacial region, with specifc characteristics, such as rapid Infltrative growth, aggressive nature, high recurrence rate and defned histopathological features [26, 27]. Since 1956, for the last six decades, many researchers started focusing on this entity. Journey of this changing nomenclature is pretty interesting (Box 27.12).

#### **Box 27.12 History of OKC**


In 2004, Reichart and Philipsen suggested a new classifcation for the odontogenic tumors, redesignated OKC as Keratinizing cystic Odontogenic Tumor (KCOT), and put it under the subcategory of "benign neoplasm of odontogenic epithelium with mature, fbrous stroma "due to its propensity for local destruction, aggressive biological behavior, and high recurrence rate and mitotic fgures seen in the suprabasal layers [29]. Shear had re-emphasized that OKC shows increased proliferative activity & high recurrence tendency and stressed on association of OKC with the Gorlin-Goltz syndrome/Nevoid Basal Cell Carcinoma syndrome (NBCCS). Some of these OKCs had association with the PTCH 1 gene mutation and increased immunohistochemical expression of proliferation markers Ki 67 and presence of PCNA (Proliferating cell nuclear antigen marker of cell replication) and p53 in KCOT. All this evidence led to change in nomenclature by WHO in 2005 [10].

This shift in tumor category suggested change in management protocol for OKC, which created a lot of skepticism, and the concept was not widely accepted, with the reason being not all OKCs possess identifable PTCH mutation. There were no clear-cut suggestions such as neoplastic title was to be applied to all OKC or to just a small subset. All relevant sequencing data on the odontogenic keratocysts has not yet been presented and still under research.

Researchers have suggested that marsupialization can revert the fragile cystic lining epithelium to normal oral mucosa or from parakeratin to orthokeratin type [30, 31].

Extensive debate (for 12 years) over putative neoplastic nature of the lesion took place. So, in 2017, a WHO expert panel declared that there is no strong affrmation to rationalize to label OKC as a neoplasm, and therefore, Odontogenic Keratocyst-OKC should be put back in cyst category and the term keratocystic odontogenic tumor (KCOT) was eliminated from the new classifcation (Boxes 27.13, 27.14, 27.15, 27.16, 27.17 and 27.18).

#### **Box 27.13 Epidemiology of OKC**

*Incidence*: Second most prevalent cysts of odontogenic origin (10–12% of all odontogenic cysts) [32].

*Age*: Wide age range. Range of occurrence between the 1st and 9th decades of life. Bimodal age distribution (frst peak at 20–30 & second at 50–60 years of age) and Predominantly in younger patients in syndromic cases.

*Sex*: Male predilection (1.6:1 ratio), More Female predilection in syndromic cases.

*Race*: predominantly in white population.

#### **Box 27.14 Site Predilection of OKC**

*Central intraosseous Lesion*—Thrice more prevalent in mandible. Seen more at various sites in following order-angle-ascending ramus, maxillary third molar region (*may involve sinus, nasal foor premaxilla, presence of impacted third molar seen, and occasionally foor of orbit involvement*), mandibular, premolar area, and maxillary canine.

*Peripheral OKC in buccal gingiva* (female predominance 2.2:1 ratio [33])

#### **Box 27.15 Number of Cysts in OKC**


#### **Box 27.16 Syndromic Associations of OKC**


#### **Box 27.17 Latest Histopathological Groups of OKC**

As per the occurrence of satellite/daughter cysts & squamous islands found in the cystic wall (Kahraman et al. [35]) (Fig. 27.17)

*Group I*: Unicystic, without any satellites (63%)


#### **27.10.1 Etiology and Pathogenesis**

Various origins—Two sources are implicated.


#### **Box 27.18 Reasons for Recurrence of OKC (13–62%; Nakamura et al.** [36]**)**


ing mucosa. (In the past designated as basal cell hamartias). Genetic factors are also always key players, especially PTCH gene aberration.

#### **27.10.2 Unique Growth Pattern—Peculiar Behavior—Pattern of Bone Involvement in OKC**

Unlike other cysts, lesion grows by extension in medullary space in anteroposterior direction, compared to osmotic expansion.

Finger-like projections are seen in marrow spaces, and enlargement goes on relentlessly along the path of least resistance. When it reaches a considerable size, it expands buccolingually also (Figs. 27.15 and 27.16).

#### **27.10.3 Radiographic Diferential Diagnosis**

OKC is a great mimic; many times, the radiographic picture is nonpathognomonic. Radiographically, the following differential diagnosis for Odontogenic Keratocyst has been suggested:

Dentigerous cyst, residual cyst, radicular cyst, lateral periodontal cyst*,* Nasopalatine cyst, Unicystic/multicystic ameloblastoma, A-V malformation, fbro-osseous lesion at initial stages, Benign intraosseous neoplasms, traumatic cyst. Patients with multiple jaw cysts should always be evaluated for basal cell nevus syndrome.

#### **27.10.4 Aspiration**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 27.15** OPG showing how lesion grows in medullary space (in anteroposterior direction), multiloculated radiolucency in left angle, and ascending ramus with impacted teeth diagnosed as OKC

#### **27.10.5 Surgical Treatment**

Incidence of these lesions is seen more in younger age group and the supportive evidence of success of conservative treatment options like marsupialisation for large expanding OKCs or two-staged surgical procedures, plus the fact of alteration of the remaining epithelium, i.e., return to more normal oral epithelium after decompression/marsupialisation has prompted many to opt for these procedures. The lesions, which are easily accessible, can be enucleated by adjunctive methods.

#### **27.10.5.1 Resection**


**HISTOPATHOLOGIC CRITERIA OF OKC-SHEAR & PINDBORG (1960–62)**

• Zone of uniform parakeratinized stratified squamous epithelium

• Picket fence / tombstone appearance of hyperchromatic palisaded

#### *Absolute indications*

• Multiple recurrences

• Thin, collapsed and folded, corrugated lining

• Weak epithelial connective tissue interface

5–8 cell layers with no rete pegs

basal cells with reversed polarity

• Presence of daughter satellite cyst

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 27.17** Typical histopathological picture of OKC showing all the features

#### 573

**Fig. 27.16** Multiple cysts in the same individual, involving both maxilla and mandible


*Follow-up*


#### **27.10.6 Basal Cell Nevus Syndrome/Nevoid Basal Cell Carcinoma Syndrome**

It is also known as bifd rib syndrome or Gorlin and Goltz syndrome or multiple jaw cyst syndrome. This is a genetically inherited uncommon affiction with autosomal dominant trait/inheritance and high penetration.

This syndrome's complex manifestations include relative frontal bossing, Ocular hypertelorism, brain tumors, midface hypoplasia, mandibular prognathism, mental retardation, schizophrenia, multiple basal cell nevi/epitheliomas on the skin, calcifcation of the falx cerebri, bifd ribs and vertebral anomalies, palmar pitting (the pits later develop into basal cell carcinoma), ovarian tumors, CNS disturbances, hypogonadism in males,cleft lip and palate, etc., and 50% of cases show multiple KCOT-now OKCs. Multiple KCOTs (OKCs) are indicative of basal cell nevus syndrome until diagnosed otherwise. 5% of the patients with KCOT/OKC are diagnosed having basal cell nevus syndrome. Early identifcation of these patients with their associated manifestations along with proper treatment planning and long-term follow-up will improve the long-term survival rate and quality of life.

#### **27.11 Conclusion**

Cysts of the jaw bones are considered as one of the most common pathologies in the oral and maxillofacial region. Various tumors mimic the clinical features of cysts and, thus, can be confused with the same. Radiography alone cannot be the diagnostic tool to distinguish various jaw cysts. Cysts are benign lesions, but few will show locally aggressive and destructive behavior. The detailed present and past history of the patient accompanied by a thorough clinical examination along with aspiration biopsy will lead to probable differential diagnosis. Both conservative and aggressive surgical treatment modalities have been used in the past to treat orofacial cysts with variable results, depending on the type of cyst. Correct fnal diagnosis, thorough planning, meticulous surgery with stringent protocols, and watchful long-term postoperative follow-up will ensure high success rate.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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Anjan Kumar Shah

#### **28.1 Introduction**

The region of Head and Neck has a wide range of pathological disorders due to the complex nature of the tissues in this region. The tooth-forming tissues can give rise to a wide array of tumours, both benign and malignant. They vary in size from tiny swelling to a large variety, causing cortical bone perforation with the displacement of the adjoining normal anatomic structures. Odontogenic tumours are slow growing and generally non-aggressive, with aggressive behaviour shown by certain tumours.

It is important for the clinician to have a thorough knowledge of the pathology, clinical as well as radiological presentation in order to manage these conditions.

#### **According to W.H.O** [1]

'Odontogenic tumours and tumour-like lesions constitute a group of heterogeneous diseases that range from hamartomatous or non-neoplastic tissue proliferations to benign neoplasms and fnally malignant tumours with metastatic potential. They are derived from epithelial, ectomesenchymal and/or mesenchymal elements of the tooth-forming apparatus. Odontogenic tumours are rare, some being extremely rare, but can pose a signifcant diagnostic and therapeutic challenge.'

The WHO frst classifed benign odontogenic tumours in 1971 followed by in 1992, 2005 and the recent classifcation was in 2017. The origin-based sub-classifcation was frst defned in 1992, which is still in use, i.e. the tumours are subclassifed into Epithelial origin, Mixed origin and

A. K. Shah (\*)

Department of OMFS, Rajarajeswari Dental College, Bangalore, India

Bhagwan Mahaveer Jain Hospital, Bangalore, India

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_28

Mesenchymal origin. The metastasising (malignant) ameloblastoma is included in epithelial origin tumour in 2017 WHO classifcation and desmoplastic ameloblastoma was excluded from the classifcation of benign odontogenic tumour. In 1992 classifcation, adenomatoid odontogenic tumour (AOT) was considered under mixed origin but in 2005 and 2017 classifcation, it is included in the epithelial origin tumour [2].

The dentinogenic ghost cell tumour (DGCT) comes under the spectrum of ghost cell lesions. Gorlin et al. in 1962 frst described calcifying odontogenic cyst (COC) as the earliest ghost cell lesions. In 2005 WHO classifcation, COC is renamed as calcifying cystic odontogenic tumour (CCOT). Fejerskov and Krogh used the term calcifying ghost cell odontogenic tumour for DGCT in 1972. Dentigerous ghost cell tumour term was given by Praetorious et al. in 1981, which is still retained in 2005 and 2017 WHO classifcation. In between, Shear in 1983 used the term dentinoameloblastoma, whereas Ellis and Shmookler proposed epithelial odontogenic ghost cell tumour. Hong et al. in 1991 suggests the term epithelial odontogenic ghost cell tumour [3, 4].

### **28.2 WHO (2017) Classifcation of Odontogenic Tumours** [5]

#### **28.2.1 Benign Odontogenic Tumours**

#### **28.2.1.1 Epithelial Origin**


**Benign Odontogenic Tumours**

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_28) contains supplementary material, which is available to authorized users.

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 577

#### **28.2.1.2 Mixed (Epithelial-Mesenchymal) Origin**


#### **28.2.1.3 Mesenchymal Origin**


#### **28.2.2 Malignant Odontogenic Tumours**


#### **28.3 Ameloblastoma**

#### **28.3.1 Introduction**

It is the most common odontogenic tumour arising from odontogenic epithelium.

Ameloblastoma originates from sources, which include 5. Ulceration or Nasal obstruction [6]


Edited 2017 WHO classifcation of odontogenic tumours has simplifed the classifcation of Ameloblastomas. It has removed the various pathologically descriptive classifcation terminologies such as follicular, plexiform, basaloid, granular or desmoplastic as these terminologies do not have any relevance to clinical behaviour. Conventional-type Ameloblastomas are characterised by multilocular, expanding behaviour. The histological margin is characterised by the infltrating margin, requires wide excision with a margin of 0.5–1 cm of normal bone, or one anatomical layer if grown out of the confnes of the bone. That is if bony cortex invaded, then take muscle or subcutaneous tissue to maintain periosteum as anatomical barrier.

#### **28.3.2 Defnition**

'It is a true neoplasm of enamel organ-type tissue, which does not undergo differentiation to the point of enamel formation" proposed by WHO. Robinson [7] defned it as a "Non-functional, unicentric, intermittent in growth, anatomically benign and clinically persistent type of tumour'

#### **28.3.3 Incidence**

It represents 19.3–41.5 % of all odontogenic tumours [8, 9]. Posterior Mandible is the commonest site of occurrence in almost 80% of ameloblastomas [10]. It occurs over a broad range; cases ranging from adults older than 90 to the children younger than 10 years. Most frequently, they occur in the second and fourth decade of life. Some authors found no gender predilection [11] while many studies showed female predilection [12] between the frst and the third decade of life [13].

#### **28.3.4 Clinical Features**


#### **28.3.5 Radiological Features**


#### **28.4 Solid/Multicystic Ameloblastoma**

In 2005 WHO classifcation, the Ameloblastoma, solid/ multicystic type, was mentioned, which is replaced by Ameloblastoma alone in 2017 classifcation again. Historically, the Ameloblastoma is classifed into Unicystic and Multilocular or Solid.

The solid/multicystic or intra-osseous ameloblastoma is locally invasive, slow-growing and odontogenic tumour of epithelial origin with a high rate of recurrence if not removed or treated properly. It has no tendency to metastasise. It invades the bone marrow spaces.

It has no gender predilection and occurs equally in both sexes. Most commonly diagnosed between 30 and 60 years of age. The posterior mandible region affected in more than eighty percent of the tumour cases. It may present as variably sized swelling of jaws. Pain and paraesthesia are rare. It usually appears multilocular (soap bubble appearance) in radiographs.

It occasionally is associated with an impacted tooth and causes expansion of the bony cortex, with the possibility of resorption of roots of the involved teeth [17, 18]. The most common histological patterns found are plexiform and follicular types. The others are desmoplastic, acanthomatous, granular and basal [2]. To confrm the diagnosis, the combination of imaging (plain as well as computed tomography) and biopsy can be performed.

The tumour infltrates through the medullary spaces and might erode the cortical bone. After resorbing the cortical bone, it may extend into the adjacent tissues. The maxillary tumours of the posterior region tend to obliterate the maxillary sinus and may extend to infltrate the skull base.

#### **28.4.1 The Treatment Goals**


The treatment depends on the best judgement of the surgeons and individual status of the patient. The surgical planning should be based on the lesions present in the mandible or maxilla. The maxilla has got higher percentage of cancellous bone, which facilitates the spread of tumour in comparison to the mandible having thick and dense cortical plates, which limit the spread of neoplasm.

The treatment of the conventional/multicystic variant is classifed into radical and conservative. The conservative methods include


Radical treatment includes resection of bone. At least 1 cm of the surrounding healthy tissues should be removed along with the tumour in cases of cortical bone perforation because if tumour cells are left behind, they may give rise to locoregional recurrence even several years after resection [20]. There is a 1.26-fold increase in the chance of the recurrence rate with the increase in the size of every 10 mm of tumour [21].

In mandible, resection can be carried out on the basis of the extension of the lesion in the form of alveolectomy, marginal mandibulectomy, segmental resection, hemimandibulectomy or hemimandibulectomy with disarticulation depending on the extension of the tumour. Based on the extension of tumour, maxillectomy (partial, total or subtotal) has been performed in radical treatment of maxillary lesions [22].

Enucleation and curettage are inadequate because the tumour invades the adjoining cancellous bone. However, some conditions in which it is carried out are given below:

#### **28.4.1.1 Indications of Enucleation and Curettage**


If enucleation and curettage has to be done, it is preferable to be carried out in association with chemical cauterisation with the help of modifed carnoy' solution and peripheral ostectomy.

The surgical treatment of solid/multicystic variant is controversial. A high rate of recurrence is reported if it is not adequately excised or resected. According to some authors, the initial treatment should be conservative as the tumour has low metastatic potential and the radical treatment should be done in cases of recurrence. While others believe that whenever possible complete removal of the tumour with preservation of lower border of the mandible will be the treatment of choice [23].

Conservative treatment has a recurrence rate ranging from 33 to 90%, as compared to the rate of recurrence by radical treatment, i.e. 7–25% in the literature. However, the patients experience serious functional and aesthetic impairments with radical treatment [24, 25]. Hasegawa et al. [26] also reported the recurrence rate of 43.5% following conservative management.

Enucleation alone showed the highest rate of recurrence amongst all the modalities of conservative management [27]. According to Esquillo ME [28], small multicystic and solid lesions can be treated by marsupialisation with good results. This will maintain good facial aesthetics of the patient, lessening the treatment cost but patients have to keep on longterm follow-up.

About 40% of intra-osseous Ameloblastomas did not recur after conservative management, which led to the conclusion that the small intra-osseous ameloblastomas can be treated with conservative management initially, leading to fewer post-operative complications and if the lesion recurs, the radical treatment can be carried out in the second-stage surgery aggressively [29].

Almeida AC et al. [30] in the systematic review and metaanalysis concluded that the bone resection should be the treatment of choice for primary multicystic ameloblastoma, also the chances of recurrence were 3.15 fold more when the conservative treatment was performed in comparison to radical treatment. Hendra FN et al. also suggest that the rate of recurrence was less when radical treatment was opted for the treatment of intra-osseous ameloblastoma in their systematic review and meta-analysis [31].

Antonoglou GN and Sandor GK [32] in the systematic review and meta-analysis concluded that no strong recommendations have been made regarding the treatment options regarding the intra-osseous ameloblastoma. However, radical treatment in the form of resection is the treatment of choice for solid/multicystic ameloblastoma.

Pogrel MA and Montes DM [33] concluded that Enucleation alone should not be the choice of treatment for multicystic or solid lesions. In the case of maxilla, partial maxillectomy and in mandibular lesions, segmental resection with 1 cm margin will be preferred to avoid recurrence.

Sampson DE and Pogrel MA [34] suggested the management algorithm for management of mandibular ameloblastoma, which is, in the case of mandibular ameloblastoma, if lesion is less than 1 cm, in plain radiograph, then curettage and cryotherapy is the treatment of choice and patient is to be kept on long-term clinical and radiological follow-up. If the lesion is more than 1 cm, CT scan is to be done. If fndings are positive, then segmental resection with involved soft tissue is carried out with suitable reconstruction and patient is to be kept on long-term clinical and radiological follow-up.

Sammartino et al. advocated the following treatment plan in Mandibular tumour management [24]. In the cases of small lesions, box resection has to be done and the patient has to keep for long-term follow-up to 10 years. For large lesions if cortical perforation is there on CT examination. Then segmental or marginal resection has been carried out along with excision of overlying soft tissues, if cortical perforation is absent then curettage is the choice of treatment with 0.5–1 cm of clinically uninvolved surrounding bone. In both cases, 10-year followup of patients is mandatory. If no recurrence occurs, orthopantomogram has to be done in every 2–3 years on the other hand if recurrence occurs, then the frst or second small recurrence can be treated with marginal resection while for the third recurrence, the segmental resection is the choice of treatment.

#### **28.4.2 Surgical Management of Ameloblastoma According to the Anatomic Locations**

#### **28.4.2.1 Mandibular Anterior Region (Canine to Canine)**

According to Gardner, anterior mandible should be approached conservatively because no important major anatomic structures are present in the anterior mandible. However, if curettage is used as a choice of treatment, recurrence is anticipated and it is preferred in smaller lesions. Always an attempt should be made to preserve the inferior border of mandibular in the anterior region because the tumour infltration is less, due to the thick cortical bone of the symphyseal region. In large lesions with cortical perforation, marginal mandibulectomy will be the choice of treatment followed by long-term followup (Fig. 28.1). After marginal mandibulectomy, the lower border of mandible is reinforced with a reconstruction plate, to avoid pathological fracture in future (Videos 28.1 and 28.2).

#### **28.4.2.2 Posterior Mandible (Bicuspid to Condyle)**

Marginal mandibulectomy should be the choice of surgical treatment for the posterior mandible and body region while maintaining the inferior and posterior border whenever possible for solid/multilocular variant. Maxillomandibular fxation might be required after marginal resection without

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 28.1** Orthopantomogram representing marginal mandibulectomy, lower border protected with reconstruction plate

continuity defects to avoid the chances of pathological fracture. A reconstruction plate may be contoured before resection, in order to maintain the normal anatomic relationship between proximal and distal segments by marking the points of screw fxation on the normal bone. In recent years, mandibular reconstruction using intra-oral microvascular anastomosis following segmental resection in cases of ameloblastomas has been carried out with great success. Most commonly, free fbular graft has been used for the same, followed by dental rehabilitation with the help of dental implants [35, 36].

#### **28.4.2.3 Anterior Maxilla (Canine to Canine)**

Goodcell JF reported 2% ameloblastomas in anterior maxilla [37]. However, Sehdev MK et al. show 9% of ameloblastomas occurs in the canine and incisor region [38]. Lessaggressive treatment has been advocated in anterior maxilla when compared to posterior, because a suffcient distance from the vital structures allows being less radical. Radical treatment in the form of partial or total maxillectomy may result in signifcant deformity.

#### **28.4.2.4 Posterior Maxilla (Bicuspid to Pterygoid Plates)**

Ameloblastoma occurs 47% in the molar region, 15% in the maxillary antrum and foor of the nose, while 9% in the premolar region.

Lack of cortical bone in maxilla makes it much more dangerous than mandibular ameloblastomas. The defnitive treatment becomes diffcult in the posterior maxillary region because tumours are not well confned by the thin maxillary cortical bone and easily spread beyond the maxillary bone boundaries. Early detection is also very diffcult. Posterior maxillary tumours are rarely treated by conservative management. Extra-oral or intra-oral resection of the tumour is carried out, sometimes Le fort I down fracture is required to access the tumours of maxillary sinus or the tumour invades the posterolateral wall of the maxillary sinus.

Weber Fergusson incision and mandibulotomy can be used for accessing the tumors of maxilla, pterygoid and infra temporal fossa. When reconstruction of the defect after maxillectomy has been planned by temporalis muscle, Rai A et al. [39] advocated use of Borle's extension weber fergusson incision.

#### **Various surgical options in management of maxilla/ mandible tumours.**

#### **Benign Mandible Tumours**

Type or surgery depends on number of factors


Based on this options starting from the most conservative to most radical are:


#### **Access incisions:**


#### **Repair:**


#### **Benign Maxillary Tumours**

Type or surgery depends on number of factors


Based on this the following excision options are possible:


#### **Access incisions:**


#### **Repair:**


#### **28.5 Reconstructive Modalities After Surgical Resection of Ameloblastoma**

#### *Need for Reconstruction:*


#### **28.5.1 Timing of Reconstruction**

Immediate reconstruction is usually performed with the help of microvascular-free faps, harvested from fbula, scapula, iliac crest and ribs. For the reconstruction of the mandible, free fbula fap is the treatment of choice. It is superior to iliac crest graft. Scapula fap for maxillary reconstruction may be a good alternative because of its long pedicle and good bone quality. For soft tissue reconstruction, the radial forearm-free fap is the choice of treatment. Most of the surgeons still prefer to use Titanium reconstruction plate for reconstruction when free faps are not possible as an immediate reconstruction modality. Delayed reconstruction (second stage) can be performed for reconstruction with the help of a titanium reconstruction plate. The immediate reconstruction signifcantly improves the patients' health-related quality of life, many patients prefer immediate reconstruction [40].

Lawson et al. [41] reported 90% success rate with delayed reconstruction in comparison to immediate, which is 46% using non-vascularised bone grafts.

Autogenous bone graft selection (Vascularised free faps vs non-vascularised bone graft) depends on following factors


The HCL classifcation [42, 43] is used as an aid in classifying mandibular defects. The defect from canine to canine, i.e. the central defect is designated as 'C'. The lateral segment defect excluding condyle designated as 'L' and when condyle is included in resection with lateral mandible the defect is designated 'H' (Fig. 28.2). The importance of this classifcation indicates that reconstruction of lateral defect can be done by straight bone segment while defect located centrally required osteotomies.

#### **28.5.1.1 Case Scenario 1** (Fig. 28.3a–g)

A 38 year old male patient reported to our outpatient department with the chief complaint of painless swelling of lower jaw since last 6 months (Fig. 28.3a). History of present illness represents swelling initially was of lemon size and increasing gradually to reach the present size, extending from right side of the body region of the mandible to the ramus region of the opposite side. On intra-oral examination, a diffuse swelling was present from one side of the molar region extending to the other side of the molar region of the mandible (Fig. 28.3b).

The orthopantomogram (Fig. 28.3c) and the CT scan (Fig. 28.3d) showing the multilocular lesion extending from the right side of the frst molar to the ramus region of the contralateral side. The incisional biopsy of the lesion confrmed the diagnosis of solid/multicystic ameloblastoma. Under general anaesthesia, the resection of the lesion was done, the complete resection of lesion was confrmed in the specimen radiography (Fig. 28.3e). The reconstruction of the

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 28.2** The HCL Classifcation

defect was done with the help of microvascular free fbula fap and with the titanium reconstruction plate (Fig. 28.3f), post-operative OPG representing reconstruction (Fig. 28.3g).

#### **28.5.2 Bone Graft Substitutes**

The calcium phosphate cement (Hydro set) is the commonly used material, which converts in situ to hydroxyapatite, serving as an effective osteoontegrative and osteoconductive material [44]. The other implantable material options include high-density porous polyethylene implants [45]. Using rapid prototype models, the custom-made implants are commonly used for the reconstruction of maxillofacial defects with good results [46].

The titanium mesh tray flled with autologous cancellous bone blocks fxed with the residual segment of bone and also titanium mesh cage flled with fresh bone marrow, recombinant human bone morphogenic protein (BMP) and xenogenic bone mineral are used for reconstruction of mandibular defect. The BMP is the key activator of bone induction [42].

Recent advances in mandibular reconstruction include transport disc distraction osteogenesis, modular endoprosthesis and tissue engineering. Dental implants are commonly used in autogenous bone grafts for the rehabilitation of masticatory functions [42].

#### **28.6 Unicystic-Type Ameloblastoma**

Robinson and Martinez [47] frst described Unicystic Ameloblastoma (UA) in 1977.

In 1988, Ackermann GL et al. [48] reclassifed UA with prognostic and therapeutic implications into three types


#### **28.6.1 Clinical and Radiographic Features**

Most of the UA clinically and radiographically resemble denigerous cysts in behaviour. Embedded teeth are associated with some UA and hence resembles residual or primordial cysts.

UA most commonly occurs in the second and third decade of life and have predilection to mandible [48]. UA many times are associated with mandibular third molars. There will be well-corticated unilocular and often pericoronal radiolucency

In some cases, root resorption can occur.

#### **28.6.1.1 Case Scenario 2** (Fig. 28.4a, b)

A 14 year old female reported with swelling on the left side of the ramus region for the past 3 weeks. OPG (Fig. 28.4a) and PA view (Fig. 28.4b) showed a large unilocular radiolucent lesion involving the whole of the ramus of the left mandible. Tooth bud of lower left third molar was absent. The lesion seemed to arise from the impacted tooth bud of lower left second molar and the lesion was also involving the roots of lower left frst molar. Under the provisional diagnosis of a dentigerous cyst, the lesion was enucleated under anaesthesia and primary closure was done and the impacted tooth bud was removed in this case. The histopathology report was that of an unicystic ameloblastoma with mural changes. The child was on follow-up with no evidence of recurrence.

On histological examination, various situations may be found such as shown in Fig. 28.5


**Fig. 28.3** (**a**) Pre-operative extra-oral view. (**b**) Pre-operative intra-oral view. (**c**) Pre-operative OPG. (**d**) Pre-operative CT Scan of the patient. (**e**) Specimen Radiography. (**f**) Clinical picture showing reconstruction with the reconstruction plate. (**g**) Post-operative OPG

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 28.3** (continued)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 28.5** Various situations of Unicystic Ameloblastoma found on Histological examination. 1. The ameloblastomatous epithelial lining. 2. An ameloblastoma nodule projects into the lumen (Luminal Ameloblastoma). 3a. Ameloblastoma islands present in the connective tissue wall of an apparently non-neoplastic cyst. 3b. Proliferation of ameloblastoma into the connective tissue wall from cystic lining. (One of the Mural variant)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 28.4** (**a**, **b**) OPG and PA view showing Unicystic Ameloblastoma

#### **28.6.2 Management**

UA treatment is controversial and can be grouped into


Conservative management has been advocated by cakarer et al. in their study on large benign aggressive lesions of the jaws, where they performed decompression followed by curettage if required [49].

Zheng et al. in 2019 published a long-term follow-up study on 116 cases of UA and have concluded that marsupialisation as an effective treatment option for UA. They found the recurrence rate more for the mural sub-types and the predictors for outcomes were resorption of the root, perforation of the cortical bone and histopathological sub-types [50].

Usually, initial treatment for UA is enucleation because they appear clinically as cysts, and the histopathology type is known only in the excision biopsy report as mural changes can be picked by the pathologist only when the full specimen is available. For histologic type showing luminal changes, the treatment of choice is Enucleation, but has to be followed up for 5–10 years. In types where the ameloblastoma infltrates the adjacent cancellous bone, marginal resection is the treatment of choice after initial Enucleation and curettage [51]. This means that patient has to undergo two surgeries based on the histopathological examination.

There is some controversy on its management, with some authors advocating aggressive management, especially for the mural variant, while others advocating conservative management such as curettage, peripheral ostectomy and various adjuvant materials such as Carnoy's solution and Liquid Nitrogen [33, 52, 53]. If adequate follow-up is possible, the UA of posterior mandible can be treated conservatively with curettage or peripheral ostectomy.

According to LAU and Samman [54], 30.5% recurrence rate reported with enucleation alone. Application of carnoy's solution along with Enucleation decrease the recurrence rate to 16% and the least percentage of recurrence was seen with resection of tumour, i.e. only 3.6%

#### **28.7 Use of Carnoy's Solution in Ameloblastomas**


that. The nerve and vessels should be avoided by contact of the carnoy's solution as much as possible. The method and duration of application of carnoy also is contentious where different regimes have been proposed by various authors.

#### **28.7.1 Case Scenario 3** (Fig. 28.6a–i)

Case scenario 3 is provided to show that conservative management with adjunctive procedures will give reasonably good results thereby avoiding major resective and reconstructive surgeries. A 21-year male reported with gradually growing swelling right side body mandible (Fig. 28.6a). OPG (Fig. 28.6b) showed an unilocular expansile lesion in right side body mandible with resoprtion of the associated roots. There was intra-oral vestibular swelling and it was fuctuant on palpation due to thinning of the labial cortex. CT views (Fig. 28.6c–e) show the lesion to be unilocular, expansile with loss of both labial and lingual cortices. An incisional biopsy was performed, which gave the report as Unicystic ameloblastoma. This could be considered as an aggressive form as there was root resorption. Considering the age of the patient, a less-radical approach was taken, which involved excision of the lesion by raising an intra-oral crevicular mucoperiosteal fap (Fig. 28.6f), extraction of all the involved teeth (Fig. 28.6i), performing a peripheral ostectomy and applying carnoy's solution (Fig. 28.6g) and also excising the overlying mucosa, which was in direct contact with the lesion. The excised cystic lesion was quite thick walled and an in toto enucleation was possible (Fig. 28.6h). A reasonable thickness of the lower border of mandible was left behind and as the alveolar part of labial and lingual cortices was removed, excess tissue was available for achieving a tension-free primary closure. The postoperative OPG at one and half years (Fig. 28.6j) shows no evidence of recurrence and prosthetic rehabilitation performed. The patient is recurrence free for past 7 years.

#### **28.7.2 Case Scenario 4** (Fig. 28.7a–f)

This case scenario is given to show that at times complex resection and reconstructive procedures may be avoided in amelobalstomas considering, the patients age and general health and other social background. In such cases where a conservative approach is used, the adjunct measures of peripheral ostectomy and carnoys solution will serve as adjunct methods to give an overall good prognosis (readers are also advised to refer chapter 27 on odontogenic cysts for use of these adjunct measures in odontogenic keratocyst).

A 67 year old male patient presented with loosening of teeth and swelling of gums in the anterior mandible

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 28.6** (**a**) Clinical image showing swelling right body mandible. (**b**) opg showing the radiolucent lesion right body mandible with root resorption. (**c**) Axial CT image showing the expansile lesion with thinning of the labial cortex. (**d**) Coronal CT image showing the expansile nature of the lesion. (**e**) 3D CT showing the erosion of both labial and lingual cortical walls. (**f**) Intra-oral intra-operative view showing the lesion exposed by crevicular fap. (**g**) Intra-oral view of the surgical bed after extraction of teeth, excision of lesion and peripheral ostectomy. (**h**) Image of the excised cystic lining, with thick walls. (**i**) Images of the extracted teeth showing the root resorption, (**j**) post operative radiograph after prosthetic rehabilitation

**Fig. 28.7** (**a**) loosening of teeth and expansion of the gums in the anterior lower mandible. (**b**) A OPG and CBCT showing multilocular radiolucency in the anterior mandible. (**c**) Lesion exposed (**d**) lesion excised and peripheral ostectomy done (**e**) carnoys solution applied to surgical bed (**f**) sixteen month post operative OPG

(Fig 28.7a). A CBCT scan (Fig 28.7b) confrmed the presence of a multilocular radiolucency in between right lateral incisor and left frst premolar region. An incisional biopsy confrmed a diagnosis of a plexiform ameloblastoma.

Considering the patient's age and general health, it was decided to follow a conservative line of treatment to avoid the need for complex reconstruction.

The lesion was exposed under general anesthesia (Fig 28.7c) and the involved teeth and tumour lining was removed. A Large round bur was then used to remove 3mm of bony walls around the locules left by the lesion (Fig 28.7d). The lesion was treated with modifed carnoy's solution for 3 minutes (Fig 28.7e) followed by irrigation with normal saline and primary closure achieved.

Excision pathology confrmed the diagnosis of a Plexiform ameloblastoma. The healing was uneventful. A 16 month post operative radiograph showed good bony healing (Fig 28.7f) without any recurrence and the patient is on long term follow-up.

#### **28.8 Extraosseous/Peripheral Ameloblastoma (PA)**

The tumour was frst described by Kuru [58] 1911. The PA is defned as the tumour having intra-osseous ameloblastoma characteristics histologically but occurs in the soft tissues overlying the tooth-bearing areas of mandible and maxilla. In comparison to the intra-osseous solid/multicystic ameloblastoma, it is the extraosseous counterpart [59].

PA representing only 1–5% of all ameloblastomas considering it as a very rare odontogenic tumour. It is also called ameloblastoma of soft tissue, mucosal origin ameloblastoma and gingival ameloblastoma. It arises from the remnants of the odontogenic epithelium with in the lamina propria gingival or from the gingival epithelium of the basal cell layer.

It is painless, frm and exophytic growth with a smooth, granular and warty surface. Most commonly located in the oral mucosa or the gingiva. It occurs in wide age range groups, i.e. from 1 to 92 years with more than 64% of cases occurring in the ffth to seventh decade of life. In edentulous areas, it affects the alveolar mucosa. The ratio of 2.4:1 is noted in mandible: maxilla. Intra-osseous ameloblastoma rarely extends to the gingival tissues and merge with gingival epithelium creating PA of the exophytic type [60]. Histopathologically same histomorphic cell types of odontogenic epithelium seen in solid/multicystic variant as consist in PA.

#### **28.8.1 Diferential Diagnosis**


It does not show invasive behaviour and the treatment of choice will be conservative excision with adequate diseasefree margins. The recurrence is low, but patients are to be kept on long-term follow-up.

#### **28.9 Metastasising (Malignant) Ameloblastoma**

'Malignant Ameloblastoma (MA)' term was proposed by Slootweg and Muller [61] in 1984. According to them, it is well-differentiated ameloblastoma that metastasises but which maintains the characteristic cytologic features of original tumour [62]. The ameloblastic tumour that undergoes malignant cytologic transformation; the term 'Ameloblastic carcinoma' is used.

Metastasis is the only factor that distinguishes ameloblastoma from MA. Its clinical behaviour is helpful in diagnosing the tumour.

Lung shows maximum 75% metastatic deposits, 15% each by spine and cervical lymph nodes followed by cervical lymph nodes and spine (15% each) [63]. Small bowel, liver, skull, brain and kidneys were the other locations, which show metastases but with lower incidence [64].

MA is very rare with an occurrence rate of 2% of all benign ameloblastomas [65]. The age ranges from 5 years to 74 with 34.4 years mean age. 1:1.2 is the male to female ratio. The majority cases were localised in the mandible. The survival time ranges from 3 months to 5 years after the appearance of metastases. Most MA are histologically plexifom type but not significantly different from the metastatic type in their histologic and cytologic features [66].

The initial tumours were treated with Enucleation and curettage while advanced with resection (block or segmental). Open thoracotomy is indicated in discrete and isolated lung metastases and wedge resection. Occasionally, chemotherapy gives successful results. Inoperable metastatic deposits can be treated with radiation therapy but having an unpredictable response [67, 68].

#### **28.10 Squamous Odontogenic Tumours**

#### **28.10.1 Introduction**

Squamous odontogenic tumour (SOT) was frst described by Pullon et al. [69] as a rare benign odontogenic tumour in 1975. It affects all the age group and equally occurs in both the jaws. SOT histologically characterised by squamous epithelial islands, which are surrounded by mature connective tissue stroma. The SOT is occasionally misdiagnosed as squamous cell carcinoma, keratocanthoma, ameloblastoma and verrucous carcinoma. It is hamartomatous epithelial proliferation, arising probably from cell rests of Malessez [70]. The differential diagnosis of SOT may be acanthomatous and desmoplastic ameloblastoma variants, squamous cell carcinoma (well differentiated).

#### **28.10.2 Defnition**

"SOT is a locally infltrative, benign neoplasm consisting of islands of well-differentiated squamous epithelium in a fbrous stroma. The epithelial islands shows foci of central cystic degeneration occasionally" (WHO).

#### **28.10.3 Clinical Features** [71]


#### **28.10.4 Radiographic Features** [72]


#### **28.10.5 Treatment and Prognosis**

Conservative treatment in the form of local excision, enucleation and curettage may be done for the successful management of SOT. Recurrent and clinically aggressive lesions have been treated with en bloc excision. Extraction of the associated teeth along with the conservative treatment is mandatory. It has a very low recurrence rate [73].

Cortical bone erosion of maxilla and mandible exhibits aggressive biological behaviour. Aggressive treatment should be followed for the lesions, which show early recurrence [74].

#### **28.11 Calcifying Epithelial Odontogenic Tumour**

Pindborg in 1955 frst introduced the calcifying epithelial odontogenic tumour (CEOT) in the scientifc literature [75]. It is well known as 'Pindborg Tumor' since then. CEOT is slow growing, benign and occasional locally invasive odontogenic neoplasm, which is epithelial in its origin.

WHO accepted and adopted the term calcifying epithelial odontogenic tumour (CEOT) in its frst edition of 'Histological typing odontogenic tumours, jaw cysts and allied lesions', and recognised it as a distinct entity [76]. It may be extra-osseous or intra-osseous.

#### **28.11.1 Defnition**

CEOT is a epithelial odontogenic neoplasm, which is locally invasive and is characterised by the presence of amyloid material that may become calcifed (WHO)

#### **28.11.2 Epidemiology**

It accounts for less than 1% of all odontogenic tumours, hence considered uncommon. It commonly occurs between the age of 8 and 92 years with the mean age of 36.9 years.

The intra-osseous variant occurs in the third, fourth and ffth decade of life in 64% of patients [77]. CEOT has no gender predilection, and occurs equally in both the sexes. Premolar and molar regions are the commonest site of occurrence, although can occur at any site. Anterior gingiva is most commonly affected by the peripheral lesions. Maximum cases reported are of intra-osseous lesions, only 6% arise in extra-osseous locations. Mandible is affected by intra-osseous lesions more frequently than maxilla, with a ratio of 2:1.

#### **28.11.3 Clinical Features**

CEOT is slowly growing, painless, expansile and hard bony swelling, which can cause thinning of the cortical bone and infltration of soft tissue subsequently. It can cause rotation, tipping, migration or mobility of tooth secondary to resorption of roots. In the anterior region, there is also a distinctly uncommon peripheral variant of CEOT, limited to soft tissue only, presenting as a nodular mass on the gingiva.

#### **28.11.4 Radiographic Features**

The larger or the mature tumour will be mixed radiolucent radiopaque, although the early tumour may be completely radiolucent. CEOT is often associated with unerupted teeth. It may be unilocular and cystic in appearance. It can demonstrate a mixture of large and small multilocular spaces described as 'soap bubble' and 'honey comb' in appearance. The radiographic borders in almost all cases between surrounding tissues and tumour appear to be circumscribed and well defned [78].

CEOT on CT examination demonstrating thinning and expansion of lingual and buccal cortical plates with welldefned mass containing scattered radiopaque areas of different size and signal intensity in mandible. Pindborg tumour on MRI reveals predominantly a hypointense lesion on T1-weighted images and mixed hyperintense lesion on T2-weighted images [79].

#### **28.11.5 Treatment**

Surgical management is the treatment of choice for CEOT. Conservative treatment in the form of Enucleation or curettage followed by judicious removal of the thin layer of bone adjacent to the tumour is the choice of treatment in small, intra-bony lesions with well-defned borders. However, the tumours treated with curettage and enucleation show a recurrence rate ranging from 15 to 30% after 2–4 years with the overall recurrence rate of 14% [77].

According to Melrose RJ [80], even the small CEOTs are infltrating in nature. A margin of about 1 cm normal bone should be removed along with the tumour excision. Peripheral tumours are treated with smaller margins 0.5 cm because they are less aggressive. Few recurrences have been reported with the tumours treated with jaw resection. However, the patient should be kept for follow-up upto 5–10 years.

The recurrent lesions and the tumours, which are diagnosed late in their clinical course, which over an extended time becomes larger and extensive (more than 4 cm in size) may not respond well to conservative management-like surgical excision only. Segmental resection such as partial or hemimandibulectomy or hemimaxillectomy will be the treatment of choice. However, it may leave a signifcant bony discontinuity requiring grafting or extensive soft tissue reconstruction.

The incidence of malignant transformation is very low; however, Veness et al. [81] reported a case of metastatic spread and malignant transformation with CEOT.

#### **28.12 Adenomatoid Odontogenic Tumour**

Stafne in 1948, frst described the adenomatoid odontogenic tumour (AOT) as an odontogenic neoplasm [82]. It was referred as ameloblastic adenomatoid tumour or adenoameloblastoma initially, because it was considered as a variant of ameloblastoma [83]. The term AOT, which is generally accepted today suggested by Philipsen and Birn [84].

#### **28.12.1 Defnition** [85]

A neoplasm of locally invasive nature was characterised by ameloblastoma-like islands of epithelial cells in a mature connective tissue stroma. Aberrant keratinisation may be found in the form of ghost cells in association with varying amounts of dysplastic dentin (WHO).

Three variants of AOT are recognised, i.e. Follicular, Extra follicular and peripheral.

The peripheral type arises from the gingival tissues and is very rare. The follicular type is commonly associated with impacted tooth and found in 75% of cases; on the other hand, the extrafollicular type is located between the roots of adjacent teeth and is not related to an unerupted teeth [86].

#### **28.12.2 Clinical Features**


Radiographically, the most common appearance will be a well-demarcated unilocular radiolucency associated with unerupted tooth. Sometimes, intra-bony cases show scattered radiopacities within the radiolucency. Intra-oral periapical radiographs found to be better than OPG are best suited for showing discrete calcifed deposits [90].

The AOT is usually well-encapsulated tumour so the treatment of choice will be Enucleation and Curettage. The recurrence is extremely rare [91].

#### **28.13 Mixed (Epithelial-Mesenchymal) Origin**

#### **28.13.1 Ameoblastic Fibroma**

Ameloblastic Fibroma (AF) was frst reported by Kruse in 1891 [92]. AF consists of odontogenic ecto-mesenchyme resembling the dental papilla, epithelial strands and nests resembling dental lamina and enamel organ. Dental hard tissues are absent in it. The lesion is referred to as ameloblastic fbro-dentinoma if there is dentin formation. It is a rare odontogenic mixed tumour in which ectomesenchymal and epithelial elements are neoplastic. It accounts only 2% of all odontogenic tumours [93].

#### **28.13.1.1 Clinical Features**

AF occurs in young adults and children with an age range from 1.5 to 42 years, with the average age ranging from 14.5 to 15.5 years [94]. It was occasionally reported in middleaged individuals. There is no gender predilection. More than 50% of patients present with a sign of swelling. Failure of tooth eruption, pain, tenderness and discharge are the other common fndings [95]. Posterior mandible is the commonest site of occurrence and frst permanent molar and second primary molar areas were involved in more than 70% of cases.

#### **28.13.1.2 Radiographic Features**

Multilocular radiolucency with sclerotic margins is the most common radiographic appearance. Unilocular radilolucency is the feature of small tumours, while large tumours extend through the bony cortices. The size typically ranges from 1 to 8 cm [96]. Ameloblastic fbrosarcoma is the differential diagnosis of AF.

Enucleation and curettage of the adjacent bone along with the extraction of affected teeth is the treatment of choice for AF. They occur rarely but required a long-term followup. In order to preserve the teeth involved in the tumour, the chances of recurrence increase after conservative management [97, 98].

The ameloblastic fbro-odontoma is composed of connective tissue characteristic of an ameloblastic fbroma and calcifed tissue identifying the tumour as a complex odontoma. The ameloblastic fbro-odontoma diagnosis is based on the histologic evidence of ameloblastic fbroma with active odontogenic epithelium embedded in an embryonal connective tissue. The differential diagnosis of ameloblastic fbroma and ameloblastic fbro-odontoma is based on the absence (ameloblastic fbroma) and presence (ameloblastic fbroodontoma) of enamel and dentin. A tumour is called ameloblastic fbro-dentinoma when exclusive dentin formation is observed. A tumour is called an ameloblastic fbro-odontoma in the presence of both enamel and dentin. In ameloblastic fbroma, no dental hard tissues are present [99]. AFO is similar to AF described by the WHO, and [they also show inductive changes that lead to both enamel and dentin formations]. Moreover, AFO and AF are defned as hamartomatous lesions and they are believed to be stages of formation of odontoma. That means the above-mentioned lesions should not be considered as distinct entities [100].

#### **28.13.2 Odontoma (Compound, Complex Types)**

In 1866, Broca coined the term 'Odontome' [101]. The term 'Odontoma' was given by Thoma and Goldman, to include tumours that were composed of well-differentiated tooth structure [102]. Odontoma defned as a tumour that differentiated and developed enough to produce dentin, enamel and cementum in varying proportions [103].

Compound odontoma is defned by the WHO as a malformation in which all the dental tissues represented in a more orderly pattern than complex odontoma, so that lesions consist of many tooth-like structures.

Complex odontoma is a type of malformation in which all dental tissues are represented and individual tissues are well formed, but occur in a disorderly pattern [104].

Compound-type odontomas are more common than complex odontomas [105]. According to Regezi, the compound odontomas are 37% and complex odontomas were 30% of all the reported odontogenic tumours [106]. Odontomas occur equally in both sexes. They are rarely associated with deciduous teeth but more frequently associated with permanent teeth. Anterior maxilla is the most common site for the occurrence of compound-type odontome while posterior mandible (Fig. 28.8) is affected more commonly in complex odontomes followed by anterior maxilla [107].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 28.8** OPG showing complex odontome in mandible right molar region

They are small, painless and hard mass. Permanent impacted or retained deciduous teeth are present as a common symptom. The second most common complaint is swelling. Complex odontoma may become large and produce asymmetry with bone expansion [108, 109].

On radiological examination, the lesion consists of densely opaque masses of varying size, usually associated with unerupted or impacted teeth. The radiolucent line surrounds the opaque masses. The collections of tooth-like structures of different shapes and sizes are the features of compound odontomes, the teeth are of diminutive sizes. The complex-type odontomes appear as calcified masses that have consistency the same as the tooth structure.

The treatment of choice for odontomes is surgical excision and recurrence is very rare.

#### **28.14 Mesenchymal Origin Tumours**

#### **28.14.1 Odontogenic Myxoma**

Myxoma is very uncommon. It accounts for 0.5 to 20% of all odontogenic tumours and has a incidence of 0.07/million [110]. It arises from mesenchymal stroma and is a benign, locally aggressive tumour. Bone, soft tissues and most frequently the myocardium are favourite sites for myxomas. Jaws myxomas are both odontogenic and osseous in the origin . Myxoma according to WHO is defned as a locally invasive neoplasm, consisting of angular and rounded cells that lie in an abundant mucoid stroma [111].

#### **28.14.1.1 Clinical Features**

The myxomas have a predilection for molar and premolar regions of mandible and maxilla, however they can occur anywhere in the jaws. One third of myxomas located in the maxilla while two third in mandible. In maxillary myxomas, the cortical expansion and perforation of bone are common and often extend into the sinus [112].

It is reported to have a slight female predilection (1.5:1) while other authors reported equal gender predilection between females and males. Odontogenic myxomas most commonly occur in the second and third decade of life with the average age ranging from 25 to 30 years [113].

The periapical radiographs and OPGs are the frst indicators of myxomas of jaws. Odontogenic myxomas radiographically present as unilocular lesions to large multilocular neoplasms, which often cause displacement of teeth but resorb the roots less frequently. The unilocular lesions are small in size on the other hand multilocular myxomas are greater than 4 cm in size. 5% Myxomas have association with unerupted tooth [114].

#### **28.14.1.2 Treatment and Prognosis**

Surgical excision is the treatment of choice of odontogenic myxomas. The rate of recurrence is quite high, i.e. nearly 25% during frst two years after removal. Atleast 1 cm of medullary bone should be resected along with tumour and always try to involve one tumour-free anatomic barrier at its periphery [78]. Subramaniam S [115] used endoscopes in the resection of pterygoid plates for the complete treatment of odontogenic myxoma. Use of endoscopes eliminates the use of extra-oral incisions.

#### **28.14.2 Cementoblastoma**

Dewy in 1927 frst described Benign cementoblastoma [116]. It is a rare tumour of mesenchymal origin. Cementumlike tissue formation around the roots of the teeth is its important characteristic.

Cementoblastoma has predilection of mandible with 79.5% and most commonly in the premolar and molar region. They rarely occur in maxilla.

The roots of vital erupted permanent tooth are affected by the cementoblastoma. The most common tooth involved is the mandibular frst molar. It has slight male predilection and occurs most commonly in the second and third decade of life. Cementoblastoma can cause teeth displacement, expansion of bone and maxillary sinus invasiveness, and aggressive tumours usually present with the symptoms of swelling and pain [117].

The diagnosis of cementoblastoma is very challenging as hypercementosis is also associated with roots of the teeth, that is the reason why hypercementosis is always included in the differential diagnosis. Cementoblastoma is slow growing, but can cause perforation and expansion of the cortices. The most common symptom is pain [118]. Radiographically the lesion will appear as a radiopaque mass fused with roots of the teeth , surrounded and limited peripherally by a radiolucent halo.

Complete excision of cementoblastoma is the gold standard treatment with extraction of the involved teeth [119]. It must be removed early, otherwise it may continue to grow. Maxillary lesions at times can involve the entire maxillary sinus making the prognosis poor. Recurrence is very rare, however incomplete removal may result in recurrence.

The tooth associated with cementoblastoma may be preserved under the following conditions [120]


#### **28.15 Recent Advances**

Genetic marking has helped identify gene mutations, which may in the future help with histological and clinical management of these lesions. The most promising of these is the BRAF V600E mutation that is present in 90% of ameloblastomas and in the unicystic mural variant, suggesting predisposition to infltrative behaviour. In the future, gene therapy may be possible using this gene marker [121].

The sonic hedgehog (SHH) and PI3K/Akt/Mtor signaling pathways may soon provide non-surgical options for treatment of ameloblastoma. The tumours that depend on active SHH signalling for growth/survival and maintenance may be susceptible targets for combined chemotherapy with SHHspecifc inhibitors together with PI3K, Akt or mTOR blocking agents [122]. Jhamb T and Kramer JM advise to check molecular markers and accordingly decide the treatment plan [123]. Effom OA et al. reported that explanation of molecular factors that arrange pathogenesis and recurrence of ameloblastoma will lead to new targeted drug therapies and diagnostic markers for ameloblastoma [124].

#### **28.16 Case Scenario 5** (Fig. 28.9a–j)

A 25 year old male patient presented with an expanding lesion around the left upper posterior teeth (Fig. 28.9a). Radiographs suggested a cystic lesion and a CT scan confrmed bony destruction by a multilocular lesion extending from the frst molar to the tuberosity (Fig. 29.8b). An incisional biopsy of the lesion confrmed a diagnosis of follicular ameloblastoma.

The patient had excision of the lesion with a posterior partial maxillectomy, with a mandibular split [125] for access (Fig. 28.9c, d). The defect was reconstructed with a temporalis muscle fap (Fig. 28.9e, f, g). The mandibulotomy site was fxed with titanium plates (Fig. 28.9h).

**Fig. 28.9** (**a**) expanding lesion around the left upper posterior teeth. (**b**) CT scan confrmed bony destruction by a multilocular lesion extending from the frst molar to the tuberosity. (**c**) Incision marked for partial maxillectomy via mandibular split access (**d**) left posterior partial maxillectomy being performed (**e**) temporalis muscle fap being

harvested (**f**) temporalis fap being advanced to the partial maxillectomy defect (**g**) Introperative view after suturing of the temporalis fap to cover the defect. (**h**) Fixation done at the mandible split region (**i**) post-operative intra oral view showing good healing (**j**) extra oral view showing good cosmetic and functional result

**Fig. 28.9** (continued)

The healing was uneventful. Pathology reports confrmed the diagnosis of Follicular Ameloblastoma with clear excision margins. He had an excellent intra oral and cosmetic (extra oral) post-operative result (Fig. 28.9i, j).

Maxillectomy through mandibulotomy approach has been followed by author in a series of cases [125].

The readers are advised to refer chapter 85 of this book for detailed reading on access surgeries and osteotomies for the maxillofacial region.

#### **28.17 Conclusion**

Posterior mandible and cuspid areas of maxilla are the most common sites for the odontogenic tumours to occur. However, they can occur anywhere in the tooth-forming apparatus. The detailed history, thorough radiological and clinical evaluation is important in making the probable diagnosis. Conservative and aggressive surgical management has been used according to the size and extent of the tumour. Proper aesthetic reconstruction should be carried out to avoid facial disfgurement. To check for recurrence, patients should be kept on regular follow-up and ensure long-term successful results.

**Acknowledgements** for Figs. 28.4 and 28.6 (case scenarios 2 and 3) to suvy manuel

#### **References**


#### **Additional Reading**

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598

## **Reactive Lesions of Oro-Maxillofacial Region**

Raja Sekhar Gali

### **29.1 Introduction**

The tissues of the oral and maxillofacial region are constantly exposed to a plethora of infammatory stimuli that can be of bacterial, physical, chemical or immunologic in the origin. Chronic/long-standing, low-grade infammatory stimuli can induce a heightened/escalated reparative response in the oral tissues resulting in the occurrence of nonneoplastic, hyperplastic lesions that are collectively referred to as reactive lesions [1].

Though the occurrence of exophytic reactive proliferation in the oral cavity is relatively common, certain malignant (metastatic/primary) and benign tumours, vascular lesions can closely mimic these lesions leading the clinician to misdiagnosis and sub-optimal treatment. A thorough understanding of the clinical presentation, differential diagnosis and the required diagnostic workup is the key to appropriate treatment.

#### **Additional features of the chapter:**


#### **29.2 Classifcation**

These lesions can be peripheral/extra-osseous (Soft tissues-Gingiva, oral mucosa etc.) or Central (intra-osseous) in occurrence.

#### *Peripheral reactive lesions:*

Eversole classifed the common peripheral hyperplastic lesions of gingiva and other oral mucosal sites into the following categories [2, 3].


#### *Central reactive lesions:*

The intra-osseous reactive lesions include the following categories [4, 5].


#### **29.3 Pyogenic Granuloma**

#### **29.3.1 Clinical Features and Aetiopathogenesis**

Pyogenic Granuloma presents as a painless pedunculated or sessile, soft feshy mass that bleeds easily with a normal or occasionally ulcerated overlying surface (Fig. 29.1). Gingiva is the most common intra-oral site, although it can affect lips, mucosa and tongue [3].

It is a localised proliferative mass occurring as a result of an exuberant reparative response to various stimuli such as chronic local irritation (calculus, overhanging restoration, a sharp margin of crown etc.), trauma, hormonal changes (Pregnancy), bone marrow transplants and reac-

R. S. Gali (\*)

Department of Oral and Maxillofacial Surgery, Narayana Dental College and Hospital, Nellore, Andhra Pradesh, India

Medicover Hospital, Nellore, Andhra Pradesh, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 599

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_29

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 29.1** Exophytic gingival growth associated with chronic gingivitis with heavy bands of calculus. The lesion easily bleeds on palpation and can occasionally cause displacement of teeth

tion to grafts. Pulp polyp or hyperplastic pulpitis is also a type of pyogenic granuloma arising in response to lowgrade chronic infection [1]. The term pyogenic granuloma is a misnomer as it does not contain pus and it is not a true granuloma [1, 3].

It can occur across all the age groups and both genders, but with a distinct predominance in females in the 2nd decade of life due to the increased levels of circulating hormones like oestrogen and progesterone [6]. Equal incidence has been reported in both the jaws with a slight predilection to anterior maxilla [1].

#### **29.3.2 Diferential Diagnosis**

Other peripheral reactive lesions that resemble pyogenic granuloma are peripheral giant cell granuloma and peripheral ossifying fbroma [3]. Peripheral ossifying fbroma has a frm consistency and a lesser tendency to bleed. Specifc proliferative malignant lesions can closely mimic pyogenic granuloma misguiding the clinician leading to sub-optimal treatment. These can be primary or metastatic squamous cell carcinomas, fbrosarcoma, Kaposi's sarcoma, oral metastatic deposits from distant primary foci like thyroid, lung kidneys etc [1].

#### **29.3.3 Diagnostic Workup**

*Radiological Features* Appreciable radiological changes are generally not seen in pyogenic granuloma, but occasionally cup-like resorption of underlying alveolar bone can be seen in a peri-apical view or an orthopantomogram. Ruling out the presence of large osteolytic lesions is required to exclude malignant lesions.

*Histopathological Features* Histologically pyogenic granulomas are classifed into two distinct sub-types- the nonlobular capillary haemangioma type (non-LCH type) and Lobular capillary haemangioma (LCH) type [6]. The non-LCH type comprises of highly vascular proliferation that is similar to granulation tissue with foci of fbrous tissue whereas the LCH type shows proliferation of blood vessels that are aggregated in a lobular fashion without any signs of infammation and or reparative response.

#### **29.3.4 Recent Concepts**

Epivatianos A et al. had demonstrated that these two subtypes have a different origin, clinical behaviour and immunohistochemical properties [7]. Their study had shown that non-LCH pyogenic granuloma presented clinically as a pedunculated mass and was mostly associated with identifable aetiologic factors and showed a histological picture of a reparative response. However, LCH pyogenic granuloma presented as a non-ulcerated sessile mass without any identifable aetiology and histological evidence of lobulated vessel pattern and the absence of infammatory reaction. This has led to the concept that LCH pyogenic granuloma represents a benign tumour of the vascular origin that develops due to unknown factors just like other benign tumours.

#### **29.3.5 Treatment**

Surgical excision of the lesion followed by removal of local irritants such as calculus, foreign body etc. is the standard treatment. Excision up to the periosteum is required in gingival lesions followed by either primary closure by mobilisation of adjacent mucoperiosteum, or surgical defect is left to heal by secondary intention by the placement of Coe pack. Brisk bleeding is often encountered during excision that would require electrocoagulation. Other treatment options include electrocautery, cryosurgery, sclerotherapy and laserassisted excision.

#### **29.3.6 Prognosis**

Complete excision of the lesion till the periosteum and removal of local aetiological factors will eliminate the chances of recurrence.

#### **29.4 Peripheral Giant Cell Granuloma**

Peripheral giant cell granuloma is the most commonly encountered giant cell containing lesion of the oral cavity that closely resembles pyogenic granuloma.

#### **29.4.1 Clinical Features and Aetiopathogenesis**

It is thought to originate mainly from the connective tissue of the gingiva or the periosteum of the alveolar ridge. It has been reported in all age groups but with a peak incidence in the 3rd and 4th decades of life with a female predominance [8]. The lesion presents as a soft proliferative mass occurring at gingiva or even at edentulous alveolar ridge. It has a tendency to bleed and may or may not be pedunculated [9].

The term 'reparative' was dropped from its nomenclature as the reparative nature could not be demonstrated histopathologically. The aetiology of this lesion remains unclear, but irritating local factors such as poor restorations, prostheses calculus etc. are thought to contribute to its origin (Fig. 29.2).

#### **29.4.2 Diferential Diagnosis**

Clinically pyogenic granuloma and peripheral giant cell granuloma are indistinguishable. Erosion of cortical bone is more commonly seen with peripheral giant cell granuloma than with pyogenic granuloma.

Histopathologically, the lesion is very similar to central giant cell granuloma, its intra-osseous counterpart [9].

#### **29.4.3 Radiologic Features**

Since the lesion is peripheral in the origin and location, radiologic changes are rarely seen. Longstanding, larger lesions can exhibit superfcial cortical erosion and may also show widening of adjacent periodontal ligament space.

#### **29.4.4 Histopathological Features**

Hyperplasia of fbroblasts with abundant multi-nucleated giant cells, with scattered areas of chronic infammatory cells and neutrophils are seen [9]. Controversy exists about the origin of the giant cells; some believe that they are of the osteoclast origin while others state that they are formed by the fusion of mono-nuclear cells. Irrespective of their origin, they are non-functional in these lesions as they are not involved either in phagocytosis or bone resorption [9].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 29.2** Peripheral giant cell granuloma, presenting as an exophytic gingival growth frm to hard in consistency causing displacement of adjacent teeth

#### **29.4.5 Treatment**

Complete surgical excision including the periosteum or periodontal ligament as applicable followed by the removal of local factors is the optimum treatment for peripheral giant cell granuloma. Recurrences are rare, but have been reported and are believed to be due to non-inclusion of periosteum or periodontal ligament during excision.

#### **29.4.6 Prognosis and Complications**

Recurrence of PGCG is infrequent, ranges as little as 5–11% have been reported. Extensive clearing of the base of the lesion, eradication of the source of irritation prevents recurrence [9].

#### **29.4.7 Recent Advances**

Increasing incidence of peripheral giant cell granulomas occurring in association with dental implants has been reported [10, 11]. Local irritant factors, infammation of peri-implant tissues are the causative factors. Clinically, these proliferations are similar to the classic peripheral giant cell granulomas and usually develop within months to years following placement of dental implants. If early detection and complete surgical excision are not performed, such lesions can lead to peri-implantitis, ultimately leading to failure of the implant necessitating its removal.

#### **29.5 Peripheral Ossifying Fibroma**

The peripheral ossifying fbroma is a reactive gingival proliferation presenting as nodular mass frm in consistency with or without ulceration. It contains fbroblastic cellular tissue with varying amounts of mineralised content that can be either bone, cementum or dystrophic calcifcation.

The term 'peripheral ossifying fbroma' literally means a benign tumour of fbrous connective tissue origin. However, this lesion is a non-neoplastic reactive proliferative lesion, so this term is a misnomer for this pathology [12].

#### **29.5.1 Clinical Features and Aetiopathogenesis**

The lesion presents as a slow-growing solitary gingival growth commonly seen during the second decade of life, predominantly in women in the anterior region of either of the jaws. The lesion is believed to originate from periodontal ligament in response to local irritation or infammation, commonly seen at the inter-dental region as a pedunculated or sessile mass (Fig. 29.3). The exact pathogenesis of peripheral ossifying fbroma is controversial. Some authors believe that it initially develops as a pyogenic granuloma that subsequently undergoes fbrous maturation and calcifcation. It is thought that these two lesions represent progressive stages of the same reactive pathology [13].

#### **29.5.2 Diferential Diagnosis**

Histopathology is the only method by which one can distinguish a peripheral ossifying fbroma from a pyogenic granuloma or peripheral giant cell granuloma [14].

#### **29.5.3 Radiologic Features**

Radiographs may occasionally demonstrate specks of calcifcations in these lesions (Fig. 29.4a–c).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 29.3** Exophytic sessile mass over gingiva at anterior maxilla associated with heavy bands of calculus and is seen to be causing displacement of teeth

#### **29.5.4 Histopathologic Features** (Fig. 29.4c)

The peripheral ossifying fbroma consists of rich fbro-cellular tissue with focal areas of mineralised deposits containing bone, cementum or dystrophic calcifcation. A chronic infammatory cell infltrate is observed at the periphery of the lesion.

#### **29.5.5 Treatment**

Complete surgical excision of the lesion with circumferential margins of 3mm of healthy gingival tissue and deep margins down to the bone, including the adjacent periosteum and periodontal ligament has to be performed to reduce the chances of recurrence [1]. Extraction of the involved teeth is to be considered in the cases of recurrent or multi-focal lesions of peripheral ossifying fbromas.

#### **29.5.6 Prognosis and Complications**

The reported reccurrence rate for peripheral ossifying fbroma is surprisingly high for a reactive proliferation. The recurrence rate has varied from 4 to 75% [15, 16].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 29.4** (**a**) Large peripheral ossifying fbroma of 6 × 7 cm in size, in a 64-year-old female, 5 years duration presenting as frm mass. (**b**) Radio-opacities on the radiograph observed in the excised lesion. (**c**) Histopathological view showing the woven bone (H&E stain, original magnifcation 400×). (Adapted from A rare massive exophytic gingival growth: Suvy Manuel et al.; Clinics and Practice. 2012 Mar 30; 2(2): e38. Open Access DOI https://doi.org/10.4081/cp.2012.e38 , copy right S. Manuel et al, CC BY-NC 3.0, Licensee PAGEPress Italy)

*Pearls, Perils and Pitfalls: Peripheral Reactive Lesions:*


#### **29.6 Central Giant Cell Granuloma** (Figs. 29.5 and 29.6)

*Synonyms* Central giant cell Lesion, Central reparative giant cell granuloma and Giant cell tumour of jaw bones.

#### **29.6.1 Introduction**

The central giant cell granuloma is one of the few maxillofacial pathologies that have generated a signifcant amount of discussion and controversy. The true biological nature of the lesion remains to be understood and the debate about labelling it as a tumour still exists [12].

Initially, it was described as Giant cell 'reparative' granuloma by Jaffe in 1953 [17] suggesting that it was a reactive response to intra-bony haemorrhage and infammation. Later, the term 'reparative' was dropped, as prior traumatic/ infammatory episodes could not be elicited in most cases and clinical progression of disease was inconsistent with the repair process of bone.

The aggressive clinical behaviour of specifc lesions demonstrated by osteolysis, cortical expansion, perforation and extension into soft tissue has led to the view that it is a benign tumour similar to the giant cell tumour of long bones [18]. The exact relationship between these two pathologies remains to be understood. The concept that these lesions represent two points in the spectrum of a single-disease process has been putforth [19, 20]. Considering the variability in clinical presentation, individual authors have classifed it as a rapidly growing & destructive—aggressive form and a slow-growing, incidentally picked up lesion—the nonaggressive form [19, 20].

Since the true neoplastic nature is yet to be established and the histologic features do not represent a true granulomatous lesion, the term central giant cell 'lesion' had been proposed by Whitaker & Waldron [20].

#### **29.6.2 Clinical Features and Aetiopathogenesis**

The lesion can occur in any age group but, children and young adults are more commonly affected and with a female predominance [19]. The anterior mandibular region is the most frequent site of occurrence almost twice as compared to the maxilla. The most common presentation is that of an asymptomatic, slow-growing, bony hard and expansile swelling of the involved jaw [19, 20]. This can be accompanied by progressive displacement/loosening of teeth, paresthesia, nasal obstruction and secondary infection leading to pain (Fig. 29.5a, b).

#### **29.6.3 Diferential Diagnosis**

Histopathologically, central giant cell granulomas and brown tumour of hyperparathyroidism are indistinguishable from each other, and this can be very misguiding to the clinician and the pathologist. Hence, biochemical tests like serum calcium, phosphate and parathormone levels are to be evaluated to rule out brown's tumour. In all cases of multi-focal and or recurrent central giant cell granulomas of jaws, the possibility of primary or secondary hyperparathyroidism is to be ruled out, so that unnecessary surgical procedures and their added morbidity can be avoided.

#### **29.6.4 Radiological Features**

The central giant cell granuloma presents as multi-locular radiolucency with scalloped margins that are usually noncorticated [19]. The cortical expansion, thinning followed by perforation, root resorption and displacement of adjacent teeth can be seen in aggressive variants [20] (Fig. 29.5c, d).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 29.5** (**a**, **b**) Central Giant cell granuloma presenting as hard bony mass over the left body of the mandible with bi-cortical expansion. (**c**) Central Giant cell granuloma presenting as a unilocular osteolytic

#### **29.6.5 Histopathologic Features**

The lesion consists of a proliferation of spindle-shaped fbroblasts in fbrous and fbromyxoid/vascular stroma [20]. Clusters of multi-nucleated giant cells are scattered throughout connective tissue stroma especially around vascular channels. These cells are believed to originate from osteoclasts or by the fusion of mono-nuclear cells [9]. Focal deposits of metaplastic bone are seen. The histological picture is precisely identical to brown's tumour of hyperparathyroidism [1].

#### **29.6.6 Treatment**

The most commonly practised and favoured treatment for central giant cell granuloma has been aggressive surgical

lesion with sclerotic border and thinning of lower border. (**d**) Occlusal radiograph demonstrating bi-cortical expansile lytic lesion with incomplete septae

curettage. Recurrence rates ranging from 20 to 50% have been reported following curettage [21]. Adjuvant treatments to curettage-like peripheral ostectomy or marginal resection have been advocated to reduce the chances of recurrence [22]. Aggressive surgical treatment options such as en bloc resection/segmental mandibulectomy/ maxillectomy are presently reserved for locally advanced lesions & recurrent lesions [22, 23]. Signifcant vascularity and intra-operative bleeding are frequently associated with these lesions. Aggressive surgical resection with 0.5 cm margins of healthy tissue is advocated to reduce the chances of recurrence [24]. However, the morbidity associated with surgical resection such as functional, cosmetic impairment, loss of teeth, teeth buds and neurosensory disturbances questions the need for such aggressive treatments in a benign reactive lesion-like central giant cell granuloma [24].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 29.6** (**a**) Swelling right side face. (**b**) Intra oral view of lesion right posterior maxilla. (**c**) CT axial cut showing changes in posterior right maxilla. (**d**) Intra operative view

*Medical Methods of Treatment* Based on the premise that osteoclastic activity steers the progression of the disease process, medical treatments aimed at antagonising the activity and proliferation of osteoclasts have been used with varying rates of success [25–27].

*Intra-lesional Steroids* Steroids have demonstrated the ability to inhibit bone resorption and induce apoptosis of osteoclasts. Weekly intra-lesional injections of triamcinolone acetonide for six weeks have shown highly variable results from partial shrinkage, in complete remission, to complete resolution leading to hypercalcification of the area [28, 29]. The protocol described involves the use of a 50% mixture of local anaesthetic and 10 mg/ml triamcinolone acetonide. Two ml of this solution has to be used for every 1cc of the lesion visible on orthopantomogram [29, 30].

*Systemic Calcitonin Therapy* Based on the observations that calcitonin receptors were found in the multi-nucleated giant cells of central giant cell granuloma and the role of calcitonin in inhibiting osteoclast function, systemic administration of calcitonin has been practised to treat central giant cell granuloma [31]. Calcitonin is administered through a sub-cutaneous or intra-nasal route. Subcutaneous administration involves 100 units per day for a period of 18–21 months during which sequential radiographs are obtained to monitor the remission of the lesion. Unlike sub-cutaneous administration, the intra-nasal route has better patient compliance but unpredictable absorption rates [31].

Results with calcitonin therapy have been highly variable. In some instances, they have been used to shrink the lesions frst, later to be followed by curettage.

*Interferon Therapy* Owing to the prominent vascular component in central giant cell granuloma, the anti-angiogenic properties of interferon alpha have been used as adjuvant therapy following enucleation/curettage of the lesion. Isolated interferon therapy without prior surgical procedure led to partial resolution of lesions and is of limited value. Kaban et al. had proposed a protocol that involved treatment of aggressive central giant cell granulomas of the mandible by a staged treatment of conservative surgical enucleation (sparing the inferior alveolar nerve and teeth). This is followed by administration of interferon Alpha 2 or beta (3,000,000 units/m2 ) 48–72 h after surgery, given once daily by a sub-cutaneous route for a period of 6 months or till a period when CT scan showed complete regeneration of bony defect [32]. Their study was based on the hypothesis that these lesions are vascular proliferations, thus explaining the high success rate in response to anti-angiogenic therapy in their experience [32].

*Bisphosphonates* Bisphosphonates that have an antagonising effect on the osteoclastic activity. Owing to the virtue of this property, bisphosphonates have been used in conjunction with intra-lesional steroids in central giant cell granuloma with promising results [33].

*Denosumab* Denosumab is a human monoclonal antibody that binds to the RANK ligand located on the surface of osteoclasts and deactivates them. The stromal cells of giant cell tumour have been shown to secrete RANKL and upregulate osteoclast activity and development. Recent Phase-II clinical trials on the use of denosumab in giant cell tumours of long bones showed that it reduces the need for morbid surgeries [34, 35]. A single report on the use of denosumab in central giant cell granulomas of jaws in two patients was recently published and had claimed very promising results involving complete remission of jaw lesions. However, studies involving a larger sample with longer follow-up periods are awaited to know the exact risk-beneft status of this novel treatment option [36].

#### **29.7 Aneurysmal Bone Cyst** (Fig. 29.7a–f)

The aneurysmal bone cyst is a controversial lesion believed to be a non-neoplastic and exaggerated reactive response of vascular tissues of bone. It is a pseudocyst that presents as expansile, osteolytic lesion often characterised by ballooning distension of the cortex, that consists of blood-flled cavernous spaces showing occasional osteoid material and multi-nucleated giant cells [37].

#### **29.7.1 Clinical Features**

The aneurysmal bone cyst generally occurs in patients less than 30 years of age with a reported higher incidence during the second decade of life with almost equal gender predilection. Aneurysmal bone cysts of the jaws are relatively rare comprising of only 1–3% of all aneurysmal bone cysts occurring in the skeleton. The posterior region of the mandible is the preferred site compared to maxilla (6:1).

Most of these lesions present as expansile swellings with or without perforation of the involved jaw bone, causing facial asymmetry or displacement of adjacent teeth and malocclusion. Pain, paresthesia and rapid progression of swelling can be seen occasionally. Dark venous blood is generally obtained on aspiration (Fig. 29.7a–c).

Pulsatile nature, thrill and bruit are generally not seen in these lesions despite the prominent vascular component associated with aneurysmal bone cysts. The presence of these signs in an expansile, osteolytic jaw lesion would rather indicate a high fow vascular malformation. The clinician should recognise this and not mistake it for an aneurysmal bone cyst, because doing an aspiration or incisional biopsy of such high fow vascular malformations can lead to disastrous bleeding and potentially fatal outcomes.

#### **29.7.2 Aetiopathogenesis**

The exact mechanism regarding the origin of aneurysmal bone cysts remains controversial. The reported hypotheses include post-traumatic, reactive malformation, genetic predisposition causing chromosomal translocation and minor vascular injury in a pre-existing bone lesion leading to pooling of blood in the stromal spaces creating bone destruction [38].

This lesion can occur de novo as a primary aneurysmal bone cyst or as a secondary phenomenon arising in preexisting lesions like central giant cell granuloma, ossifying fbroma, fbrous dysplasia, osteosarcoma, fbrosarcoma and other lesions [38]. It has been postulated that injury to the capillary network in these lesions leads to extravasation of blood. The associated capillary blood pressure readily destroys unsupported stroma resulting in a blow out reaction thereby producing the expansile and destructive aneurysmal bone cyst.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 29.7** (**a**) Swelling left side body mandible. (**b**) Intra oral view of swelling left lower posterior buccal cortex. (**c**) Aspirate showing blood tinged fuid. (**d**) OPG showing lesion left body mandible. (**e**) Axial CT

scan showing the expansile lesion. (**f**) 3D CT showing the destruction of bone

#### **29.7.3 Radiologic Features**

Owing to its osteolytic nature, aneurysmal bone cyst presents as unilocular or multi-locular radiolucency often associated with cortical thinning and perforation with resorption of roots seen occasionally. A classic sign commonly seen is the 'ballooning' distension of the thinned out cortex occurring as a result of a thin outline of reactive sub-periosteal bone formation. CT and MRI scans of such lesions often demonstrate blood and free fuid in these cavities (Fig. 29.7d, e, f).

These typical features can sometimes be masked in those aneurysmal bone cysts occurring as secondary phenomena in pre-existing bone lesions. Such aneurysmal bone cysts present as mixed radiolucent-radiopaque lesions.

#### **29.7.4 Histopathological Features**

Histopathologically, it consists of variable amounts of fbrous connective tissue stroma with blood-flled sinusoidal spaces, multi-nucleated giant cells and reactive woven bone/osteoid. Correlating the histopathological and clinical features, three variants of aneurysmal bone cysts were proposed namely, the solid type, vascular type and mixed type [39]. The solid type is associated with a dense stroma, few sinusoidal spaces and blood vessels that correlates with the absence of cortical perforation clinically and minimal bleeding observed intra-operatively. The vascular variant falls into the other end of the spectrum that shows loose fbrous tissue stroma with large blood-flled cavernous spaces causing extensive osteolysis and cortical perforation that is frequently associated with brisk intra-operative bleed. The mixed variant shows characteristics of both these sub-types.

#### **29.7.5 Treatment**

Complete Surgical curettage of the lesion is the most commonly followed treatment modality. Adjuvant therapies like cryosurgery and electrocauterisation have been used to reduce the chances of recurrence. Due to its vascular nature, brisk bleeding is often encountered during surgery that generally ceases after complete removal of the lesion. Preoperative embolisation had been advocated in extensive, vascular variants of aneurysmal bone cysts to reduce intraoperative blood loss.

Resection is generally reserved for aggressive aneurysmal bone cysts that have extensively resorbed the lower border of the mandible or have caused a pathological fracture and lesions that have recurred following conservative therapy. The decision to perform segmental resection is also infuenced by the nature and extent of primary jaw pathology in which the aneurysmal bone cyst has arisen. Segmental resection has been recommended as the treatment option for secondary aneurysmal bone cysts occurring in ossifying fbromas, giant cell granulomas and osteoblastomas [40].

#### **29.7.6 Prognosis and Complications**

Aneurysmal bone cysts have relatively higher recurrence rates compared to central giant cell granuloma [38]. This has been attributed to incomplete removal of the lesion during curettage/marginal mandibulectomy. The multi-locular nature of the lesion can sometimes limit the access leading to residual pathological tissue that causes increased intraoperative bleeding and also gives rise to recurrences usually in the frst year following surgery.

### **29.8 Brown Tumour of Hyperparathyroidism** (Fig. 29.8)

Brown tumour is a misnomer as it is not a true neoplasm, but a localised area of osteolytic defect caused by increased osteoclastic activity and demineralisation of bone that is induced by excessive secretion of parathyroid hormone. It is considered to be an intra-osseous reactive lesion [4].

#### **29.8.1 Etiopathogenesis**

Hypersecretion of parathyroid hormone can occur due to Primary (benign/malignant adenoma of parathyroid gland), secondary (pre-existing kidney disease leads to compensatory overactivity of parathyroid) or tertiary causes (parathyroid tumours arising due to prolonged hyperactivity induced by secondary causes). Irrespective of the origin, the resultant effect is hypercalcaemia (caused by mobilisation of calcium from bone to bloodstream) and altered phosphate levels that give rise to the entire spectrum of signs and symptoms of this disease. These include disturbances in ion metabolism, demineralisation of bone, kidney stones, gastrointestinal disorders and muscle weakness. Hence, hyperparathyroidism is also referred to as the 'disease of bones, stones, abdominal groans and psychic moans' [41].

#### **29.8.2 Clinical Features**

Brown tumour is a localised, lytic bone defect characterised by a mass of reactive fbrous tissue that presents as swelling with cortical expansion, perforation occasionally associated with pain and pathological fracture. The lesion occurs in adults above 50 years of age and has a female to the male pre-dilection of 5:2 and can occur in any bone but more common sites are long bones, pelvis, ribs, maxilla and mandible [42]. Co-existing multiple synchronous lesions in the jaws and at other skeletal sites can also occur posterior maxilla. (**b**) Lesion anterior mandible. (**c**) OPG showing the changes (red circles)

©Association of Oral and Maxillofacial Surgeons of India

[43] (Fig. 29.8a–c). Bone manifestations usually occur in the late stages of hyperparathyroidism, and brown tumours are picked up during the diagnostic work-up for the same. Rarely, brown tumour of the jaw may be the frst manifestation of primary hyper parathyroidism [44, 45]. They can cause signifcant bone destruction leading to facial asymmetry, displacement of teeth, malocclusion pathological fracture etc.

#### **29.8.3 Diagnostic Workup**

Since it is not possible to histopathologically distinguish brown tumour from central giant cell granuloma, biochemical tests are mandatory to confrm its diagnosis. Elevated serum calcium (>10.4 mg/dl), decreased serum phosphate level, elevated parathormone levels, ultrasonography to identify parathyroid adenomas (primary hyperparathyroidism), and renal function tests to rule out renal disease (secondary hyperparathyroidism) constitute the sequence of diagnostic work up to diagnose hyperparathyroidism [45].

#### **29.8.4 Diferential Diagnosis**


#### **29.8.5 Radiographic Features**

It shows a well-defned mono-locular or multi-locular welldemarcated lesion that is purely lytic. There are signifcant root resorption and loss of lamina dura.

#### **29.8.6 Histopathology**

Brown tumour very closely resembles central giant cell granuloma, and these two lesions are indistinguishable on histopathology. Features such as the proliferation of multi-nucleated giant cells, osteoclasts present in a rich fbro-cellular and vascular connective tissue stroma with scattered areas of haemorrhagic foci and haemosiderin pigmentation are seen. The presence of haemosiderin renders this lesion its characteristic brown/brownish yellow colour and hence the name brown tumour.

#### **29.8.7 Treatment**

Spontaneous resolution/remission of brown tumour generally occurs after treatment of the underlying cause of hyperparathyroidism. Primary hyperparathyroidism is treated by excision of parathyroid adenoma/gland. Treatment of renal disease, vitamin D defciency is done in the cases of secondary hyperparathyroidism. Refractory lesions that fail to resolve or incomplete remissions after treatment of underlying cause would require surgical curettage [44, 45].

#### **29.8.8 Prognosis**

Brown tumours are generally slow-growing lesions that can be locally destructive. Invasion into surrounding structures may cause a variety of symptoms. Small lesions usually resolve spontaneously once the underlying condition (hyperparathyroidism) is treated whereas large lesions take about 6–12 months to subside.

#### *Pearls, perils and pitfalls:*


#### **29.9 Chronic Sclerosing Osteomyelitis and Garre's Osteomyelitis**

Chronic sclerosing type of osteomyelitis occurs as a result of low-grade and long-standing infection of the marrow spaces that is characterised by areas of reactive bone sclerosis extending over a larger area (diffuse sclerosing) or localised to one or two teeth (focal sclerosing) [4].

Garre's osteomyelitis also known as proliferative periostitis is a sub-type of osteomyelitis that occurs in children. It is characterised by reactive sub-periosteal bone formation in response to chronic low-grade infection. Predominantly occurring in the posterior region of the mandible, it is best seen on an occlusal radiograph or an axial section CT scan as onion skin-layered appearance of the expanded bony cortex.

Rarely, malignancies like osteosarcoma (juxtacortical and parosteal), chondrosarcoma, fbrosarcoma and others can closely mimic Garre's osteomyelitis leading to a diagnostic dilemma and sub-optimal treatment.

These lesions are discussed in detail in other chapters of the book.

#### **29.10 Conclusion**

A variety of reactive soft tissue and bony pathologies occur in the oro-facial region that arises in response to chronic lowgrade infammation, trauma, metabolic and hormonal infuences. These lesions very closely mimic benign and malignant neoplasms in their clinical, radiological and histological presentations. Knowledge about their etiopathogenesis, clinical behaviour patterns is of paramount importance for providing appropriate treatment.

#### **Case Scenario 1** (Fig. 29.5)

A 53-year-old male patient reported with a chief complaint of bony hard swelling over the left side lower jaw of 8 month duration.

#### **Clinical Examination**

Bony hard swelling over the left body of the mandible was noted with the expansion of buccal and lingual cortical plates (Fig. 29.5a, b).

#### **Pre-operative Diagnostic Work-up**

*Imaging*: Orthopantomogram revealed unilocular radiolucency with a sclerotic border and x-ray occlusal view showed a bicortical expansile, osteolytic lesion at the left body of mandible, with areas of osteosclerosis (Fig. 29.5c, d).

*Incisional Biopsy*: Incisional biopsy done under local anaesthesia proved it to be central giant cell granuloma. Biochemical tests for assessment of serum parathormone, calcium, phosphate levels were performed, and the possibility of brown tumour of hyperparathyroidism was ruled out.

*Diagnosis*: Central Giant cell granuloma of mandibular body. *Surgical Plan*: Considering bi cortical perforation and

thinning of lower border caused by the lesion, segmental mandibulectomy through submandibular approach + mandibular reconstruction plate fxation was performed.

*Postoperative Period*: Post-operative period was uneventful. The patient was last seen three years after surgery and was found to be recurrence-free.

#### **Case Scenario 2** (Fig. 29.6a–d)

A 60-Year-old male with a complaint of an asymptomatic slow-growing swelling in the upper jaw of 10 months duration.

#### **Clinical Examination**

A single frm to hard swelling measuring approximately 4 × 3 cm located over the right maxillary posterior alveolus causing buccolingual expansion, vestibular obliteration was found. It was extending from the mesial aspect of right maxillary 1st molar to the maxillary tuberosity area. The swelling was non-tender, frm to hard in consistency, with normal overlying mucosa. There was associated odontogenic focus of sepsis, but there was grade-II mobility of right maxillary 1st molar.

#### **Pre-operative Diagnostic Work-up**

*Imaging*: A pre-operative CT scan revealed a unilocular radiolucency with scattered areas of radio-opacity located at right maxillary posterior alveolus that was causing buccal cortical expansion, thinning and even perforation with denuding of the roots of the 1st molar. Superiorly the lesion was found to be extending till the body of the zygoma and just abutting the foor of the maxillary sinus.

*Histopathological and Biochemical Evaluation*: An incisional biopsy of the lesion was performed under local anaesthesia, that was reported as a central giant cell granuloma of the maxilla. A thorough biochemical evaluation was done to rule out brown tumour of hyperparathyroidism as both the lesions are indistinguishable histopathologically. Serum calcium, parathormone, and phosphate were within the normal limits.

*Diagnosis*: *Central Giant cell granuloma*—Right maxillary posterior alveolus.

*Surgical Plan*: Extended alveolectomy of the right posterior maxillary alveolus + nasal antrostomy + two-layered closure of the resultant defect with oroantral communication by mobilisation of the buccal fat pad and adjacent Buccopalatal mucoperiosteum. Following excision of the lesion, since maxillary sinus was breached, the resultant defect was packed with ribbon gauzed soaked in whitehead's varnish, and a trans nasal inferior meatal antrostomy was done, through which the tip of the pack was brought outside and knotted for removal on the 12th day. A two-layered watertight closure of the wound was achieved.

*Post-operative Period*: The wound healed uneventfully. The patient was last seen 4 years post-operatively and was free of disease.

#### **Case Scenario 3** (Fig. 29.7)

A 38-year-old female with a complaint of swelling at the left side lower jaw of 1-year duration.

#### **Clinical Examination**

Figure 29.7a A single frm to hard swelling was located over the left body of mandible, non-tender with normal overlying skin & mucosa. On palpation, buccal and lingual cortical plate expansion (Fig. 29.7b) with eggshell crackling signpositive suggestive of expanded and thinned out cortical plates causing microfractures on digital pressure.

#### **Pre-operative Diagnostic Work-up**

*Imaging*: Orthopantomogram revealed a radiolucent lesion in the left body of the mandible with focal radio-opacities located in the anterior aspect of the lesion. The lesion was causing root resorption, thinning of mandibular lower border and was extending from lower left 2nd molar to lower left lateral incisor (Fig. 29.7d).

CT scan confrmed the presence of an expansile, lytic lesion with a characteristic 'ballooning distension of the buccal and lingual cortical plates'. It also showed scattered areas of radio-opacities & multilocularity in the anterior region of the lesion and bi-cortical perforation along its posterior aspect.

'Ballooning distension' of the cortex with scattered areas of radio-opacities within a radiolucency was suggestive of secondary aneurysmal bone cyst arising in a pre-existing lesion (Fig. 29.7e).

Reconstructed CT scan showing bi-cortical perforation and lower border thinning at the mandibular body (Fig. 29.7f).

*Aspiration*: Figure 29.7c Dark venous blood of about 8–10 ml could readily be aspirated from the lesion.

*Incisional Biopsy*: Correlating the bloody venous aspirate, clinical & radiological fndings, a clinical diagnosis of the aneurysmal bone cyst was made. However, owing to the change in radiodensity in the anterior aspect of the lesion (as evident on CT scan), an incisional biopsy was performed to rule out the presence of a hybrid lesion or co-existing pathology.

*Diagnosis*: A histopathological diagnosis of *secondary aneurysmal bone cyst arising in ossifying fbroma* of the mandible has been made.

*Surgical Plan*: Considering the hybrid nature of the lesion, bi-cortical perforation, thinning of lower border, the proposed surgical plan was segmental mandibulectomy and reconstruction.

#### **Case Scenario 4** (Fig. 29.8)

A 40-year-old female patient reported with a complaint of swelling over the lower jaw of 18 months duration and swelling over the right side of the upper jaw of 6 months duration.

#### **Clinical Examination**

A frm to hard swelling was noted in the mandibular anterior dentoalveolar region extending from right lower 2nd premolar to lower left lateral incisor (Fig. 29.8a). There was a displacement of lower anterior teeth. Another similar frm swelling was noted in the right maxillary posterior dentoalveolar region in the region of missing right 1st maxillary molar (Fig. 29.8b). Overlying mucosa appeared normal in both the swellings.

#### **Pre-operative Diagnostic Work-up**

*Imaging*: Figure 29.8c Orthopantomogram revealed a unilocular radiolucency with a sclerotic border located in relation to the periapical region of right lower premolars. A poorly defned mixed lesion (radiolucent lesion with foci of radio opacities) was noted in the right maxillary posterior region.

*Incisional Biopsy*: An incisional biopsy of both the lesions was performed under local anaesthesia. Both the lesions were reported as central giant cell granulomas.

*Biochemical Evaluation*: Since synchronous giant cell granulomas are generally rare and as these lesions are histopathologically similar to browns tumour, biochemical evaluation was performed. Serum parathormone was remarkably elevated along with raised serum calcium levels, while renal function parameters were well within normal limits.

*Ultrasound Evaluation of Neck*: An ultrasound evaluation of neck revealed parathyroid adenoma on the left side.

*Diagnosis*: After correlating the biochemical and sonographic examination, a diagnosis of primary hyperparathyroidism is made. The osteolytic lesions of mandible and

*Surgical Plan*: The patient was advised parathyroidectomy for primary hyperparathyroidism followed by the wait and watch policy for synchronous brown jaw tumours to undergo self-resolution. But spontaneous resolution the jaw lesions was very slow following eight months after parathyroidectomy and the patient wanted surgical removal of the brown jaw tumours. They were treated by marginal mandibulectomy and alveolectomy of posterior maxilla.

#### **References**

#### **Reactive Lesions of Oro-facial Soft Tissues**


#### **Central Giant Cell Granuloma**


#### **Aneurysmal Bone Cyst**


#### **Brown Tumor**


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## **Fibro-osseous Lesions in the Maxillofacial Region**

Taranjit Kaur

Fibro-ossoeus lesions have posed a diagnostic dilemma since the beginning, when frst case was reported in late 19th century. Since then various lesions are included in this group, yet the understanding of the lesions remains obscure for the clinican/surgeon. The main reason for this, is their histological resemblance with one another, where they all show varying degrees of healthy bone replaced by fbrous tissue and some amount of bone/cementum like tissue intermingled in between. This chapter is written with the aim of simplifying these group of bony lesions for its readers and highlighting the key idea of interdisciplinary approach in the management of these lesions where the oral pathologist along with radiologist and clinician play a pivotal role in differentially diagnosing these lesions, for the maxillofacial surgeon to chose and perform her/his duty of managing them, rightfully, for their patients. The spectrum of these lesions have seen several changes during the course of history yet there is still ample scope for ambiguity in identifcation and classifcation of the lesions, hence the authors have chosen few most commonly encountered lesions in Indian subcontinent, for the description and discussion.

#### **30.1 Introduction**

Fibro-osseous lesions (FOLs) are miscellaneous and challenging group of intra-osseous lesions posing a diagnostic dilemma for the clinician as well as the pathologist and this makes them interesting to treat and manage for the surgeon [1]. It was Boyko who frst reported a case of craniofacial fbrous dysplasia, diagnosed at that time as osteofbroma, in 1936, which was called leontiasis ossea, the term frst described by Virchow in 1862, for bony lesions involving upper facial bones resulting in lion-like faces. Clinicians and pathologists have gone through a drastic change in their understanding of these lesions since then yet pathogenesis and progression still needs further investigation [2].

One thing that is common in all these lesions is that normal bone is replaced by connective tissue and fbroblasts; occasional foci of mineralisation is seen, with varying degrees of bone- or cementum-like tissue. The biological behaviour of these lesions ranges from benign and indolent to aggressive, infammatory and neoplastic [1].

The diagnosis is diffcult to obtain on the basis of histopathology alone, clinical history and radiographic details have an important role to play in the decision-making of the management. Most often than not, pathologists may not be able to comment more than just benign fbro-osseous lesion in the absence of additional clinical and radiographic information [1].

Though considered as one of the most confusing and challenging pathological processes, it was the meticulous hard work of Charles A Waldron, an American Oral Pathologist, who was frst to describe these lesions in a systematic way and propose the classifcation, in the year 1985, which was later revised by himself in the year 1993 [3, 4].

With the evolution of technology and a better clinical understanding of the lesions as well as the availability of ample literature, various other classifcations have emerged from time to time [5, 6].

### **30.2 Classifcations**

Fibro-osseous lesions have undergone a turbulent phase with regard to its classifcation and categorisation and in this chapter, it may not be possible to include all the available classifcations, but the major ones have been referred to. The major changes in classifcations are seen in the publications by Waldron [5], Waldron [6], Slootweg [7], WHO [8], Speight

**30**

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K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_30

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_30) contains supplementary material, which is available to authorized users.

T. Kaur (\*)

Department of Oral and Maxillofacial Surgery, Government Dental College and Hospital, Jamnagar, Gujarat, India

and Carlos [9] and Eversole et al. [1]. As all the changes in classifcations have not been included in the chapter, readers are encouraged to refer the concerned publications. Some of the commonly used classifcations are as follows.

#### **30.2.1 Waldron's Classifcation, 1985 [5, 10]**

	- (a) Monostotic
	- (b) Polyostotic
	- (a) Periapical cemental dysplasia
	- (b) Localised fbro-osseous-cemental lesions (presumably reactive in nature)
	- (c) Florid cemento-osseous dysplasia (gigantiform cementoma)
	- (d) Ossifying and cementifying fbroma
	- (a) Cementoblastoma, osteoblastoma and osteoid osteoma.
	- (b) Juvenile active-ossifying fbroma and other so called aggressive-ossifying/cementifying fbromas.

#### **30.2.2 WHO Classifcation of FOLs, 2005 [8]**

At the core of these classifcations is the spectrum of clinicopathological entities in which the diagnosis can only be made by the correlation of clinical, radiological and histological features.

	- (a) Periapical osseous dysplasia
	- (b) Focal osseous dysplasia
	- (c) Florid osseous dysplasia
	- (d) Familial gigantiform cementoma

### **30.2.3 Speight and Carlos Classifcation (2006)** [9]

	- (a) Monostotic FD
	- (b) Polyostotic FD
	- (c) Craniofacial FD
	- (a) Periapical Osseous Dysplasia
	- (b) Focal Osseous Dysplasia
	- (c) Florid Osseous Dysplasia
	- (d) Familial Gigantiform Cementoma
	- (a) Conventional Ossifying Fibroma
	- (b) Juvenile Trabecular-Ossifying Fibroma
	- (c) Juvenile Psammomatoid-Ossifying Fibroma

#### **30.2.4 Eversole Classifcation, 2008 [1]**

In 2008, Eversole et al. gave a comprehensive classifcation by including developmental lesions, neoplastic lesions and infammatory/reactive processes. This classifcation emphasised that fnal diagnosis can be attained by the correlation of microscopy, imaging and clinical features together and not on the basis of histopathological features alone.

	- (a) Fibrous dysplasia
		- (i) Monostotic
		- (ii) Polyostotic
		- (iii) Polyostotic with endocrinopathy (McCune-Albright)
		- (iv) Osteofbrous dysplasia
	- (b) Osteitis deformans or Pagets disease
	- (c) Pagetoid heritable bone dysplasias of childhood
	- (d) Segmental odontomaxillary dysplasia
	- (a) Focal cemento-osseous dysplasia
	- (b) Florid cemento-osseous dysplasia
	- (a) Focal sclerosing osteomyelitis
	- (b) Diffuse sclerosing osteomyelitis
	- (c) Proliferative periostitis
	- (a) Hyperparathyroidism
	- (a) Ossifying fbroma
	- (b) Hyperparathyroidism jaw lesion syndrome
	- (c) Juvenile-ossifying fbroma
		- (i) Trabecular type
		- (ii) Psammomatoid type
	- (d) Gigantiform cementomas

Based on the above-mentioned classifcation systems, author have selected few most commonly occurring BFOLs (Benign fbro-osseous lesions), which will allow a better understanding of these lesions, from a maxillofacial surgeon's point of view.

It is apparent from this wide spectrum of FOL that a diagnosis cannot be made from pathology reports alone and it has to be correlated with the clinical and radiological fndings [11]. BFOL form a wide spectrum of diseases, which occur intra-osseously and is characterised by similar microscopic pictures with hypercellular fbroblastic stroma and varying amounts of bone, cementum and other calcifed structures. El Mofty stated that reactive, dysplastic, developmental and neoplastic processes are included under the broad umbrella of BFOLs and the treatment given varies from case to case [12].

#### **30.3 Fibrous Dysplasia (FD)**

Fibrous Dysplasia is a benign dysplastic disease with a wellapproved genetic cause in GNAS 1 (Guanine nucleotidebinding protein alpha-stimulating activity polypeptide 1) gene. The clinical severity of the disease depends on the stage of foetal life (prenatal/postnatal) at which gene mutation occurs. So far, the identifcation of *GNAS1* mutations are the most useful molecular tool to differentiate fbrous dysplasia from other fbro-osseous lesions [13].

#### **30.3.1 Clinical Features**

There are four main clinical subtypes of FD depending on the time of mutation in GNAS 1


Craniofacial variant will be discussed in detail, as it is the most common FD encountered in the maxillofacial region.

FD is the disease of growing bones and the majority of lesions are diagnosed in frst two decades of life, without any predilection for gender or race. Though mandibular lesions are purely monostotic, but the lesions involving maxilla, which invariably involve zygoma, sphenoid and other adjoining bones of the craniofacial skeleton, are not truly monostotic and hence may be suitably referred to as Craniofacial FD. Since multiple adjoining bones are involved of the same anatomic region, term polyostotic is avoided. Craniofacial FD appears in few commonly seen patterns,

One, involving maxilla-zygoma-sphenoid-frontal-nasal bones. Another, involving frontal-temporal-sphenoid-zygoma bones

Clinically, painless expansion of the affected area with facial asymmetry is the common presentation of FD. Rarely does a lesion expand the bone to cause structural weakening. Thickening of the skull bones and obliteration of the foramina of the base of the skull occasionally can present variously as headache, proptosis, visual loss, anosmia and hearing loss.

#### **30.3.2 Radiographic Features**

Radiographic features vary depending on the stage at which the lesion is diagnosed. Early onset lesions appear radiolucent and later as they age, the classical 'ground glass appearance' (Fig. 30.1) is the identifying feature.

The lesion is ill defned and is radiologically imperceptible from the adjoining normal bone. Ground glass appearance is due to radiodensity caused by abundance of woven bone, which also leads to fuzziness of the boundaries, and strict delineation of lesion from the normal bone is diffcult on the radiograph. Poorly defned borders are the diagnostic clue for FD and also differentiate it from Ossifying fbroma, which has well-defned appearance on the radiograph. Publications have stressed on the importance of CT and CBCT as investigative modalities of FOLs [14].

The clinical case scenarios 1 and 2 are provided for the readers to appreciate the difference in the CT images between early and long-standing lesions

#### *Clinical case scenario 1* (Fig. 30.2a–e)

A 17-year-old male with noted swelling in the upper right maxilla posterior vestibule region and he was aware of the swelling for about 1 month.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 30.1** Occlusal image showing ground glass appearance in a 36-year-old female, who had aymptomatic bilateral body region mandible swelling

618

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 30.2** (**a**) Clinical picture of FD right upper posterior buccal sulcus. (**b**) Occlusal view showing ground glass appearance, no root resoprtion, no root displacement, hazy margins, lamina dura appeared to be lost in IOPA. (**c**) Axial view CT. (**d**) Coronal view CT. (**e**) Sagittal view CT

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 30.3** (**a**) Clinical image. (**b**) Coronal CT showing more dense/opaque appearance of the lesion. (**c**) Axial image

Clinically, the lesion was Ovoid, well defned, non-tender and frm with no palatal expansion, involving the buccal suclus of tooth 13–16 (Fig. 30.2a).

Occlusal X-ray showed ground glass appearance (Fig. 30.2b), There was no root resorption, no root tilting, margins were hazy and lamina dura lost.

CT scan shows well-defned lesion (Fig. 30.3c–e—axial, coronal and sagittal views, respectively).

The Calcium and Phosphorous values were normal.

A bone incision biopsy was done and the fnal diagnosis was that FD. It was decided to observe the lesion till growth is completed; however, the patient was lost for follow up

#### *Clinical case scenario 2* (Fig. 30.3a–c)

This patient in his late thirties was aware of the swelling on the right posterior upper jaw for past 5-6 years. After an initial biopsy proved it to be FD, the lesion was excised completely under GA.

#### **30.3.3 Histological Features**

Histologically, FD shows irregularly shaped trabeculae of immature woven bone dispersed in cellular fbroblastic stroma. The bone trabeculae evolve directly from stroma and assume delicate curvilinear patterns, which appear like 'Chinese letters' [15]. The osteoid is generally not rimmed with osteoblasts and develops into lamellar bone as the lesion matures. Such may not be the case with extra gnathic lesions.

#### **30.3.4 Treatment and Prognosis**

In a large majority of cases, lesions show the tendency of slow growth and eventually stabilise with the cessation of the growth phase. Indications for surgical treatment include functional defcits or signifcant cosmetic deformity. The aim of treatment is to restore function and cosmetic symmetry.

The involvement of the bone may range from minimal to functional and/or esthetic deformity being present. Based on patient's age, the presence/absence of cosmetic and functional defcits and the growth rate, the treatment is currently designed in the following way [16] (Video 30.1).


In the case of minimal involvement, no surgical intervention may be needed but when involvement is more signifcant, surface shaving of excess bone, for cosmetic reasons may be done. Radical surgical approach is preferred in the case of signifcant functional and aesthetic defcit.

A treatment scheme offered by Chen in 1990 [17] is helpful in determining the approach depending on the extent of conditions. The lesions are defned as per the regions, in Zone 1, i.e. frontomaxillofacial are, it is advised that they are completely excised and reconstructed henceforth. In Zone 2, i.e. hair-bearing cranium, observation and conservative or radical approach as and when needed. Whereas in Zone 3, which is central cranial base, more conservative or observational approach is required due to the diffcult location of neurovascular bundle, lastly Zone 4 lesions involving dentate maxilla and mandible are advised conservative treatment in the form of surgical recontouring and shaping. Optic canal decompression was advised on patients with orbital dysplasia and decreasing visual acuity.

Riclade in 2001 in his review article stated that in craniofacial dysplasia, early treatment is advised in progressive sensory disturbances, in order to reduce the problems caused by decompression at a later stage [18].

Non-surgical treatment has a limited role, radiotherapy is contraindicated. Steroids show some effectiveness in reducing bone pain and temporary relief from symptoms due to nerve compression. Calcitonin and pamidronate have shown some promise in recent studies but the results of long term trials are awaited [16].

Monostotic lesions of the craniofacial complex need to be differentiated from other FOLs like cemento-ossifying fbroma (COF) and diffuse-sclerosing osteomyelitis of the mandible [15] while COF most commonly appears in young adults in tooth bearing areas of mandible and maxilla, it is well defned and can be separated or scooped out from the adjoining healthy bone easily.

*Clinical case scenario 3* is a 14-year-old boy who reported with a recurrent lesion on upper left buccal posterior alveolus. The clinical, radiological and surgical fndings were suggestive of a COF; however, the pathology report was that of FD. This case is shown to highlight the varied pathology reports, which can be expected in dealing with lesions under the BFOL spectrum (Fig. 30.4a–d).

*Clinical case scenario 4* (Fig. 30.5a–c) is given to show lesion, which had initial differential diagnosis of FD, but pathology report showed it to be sclerosing osteomyelitis

In 2008, eversole classifcation infammatory reactive process containing focal sclerosing osteomyeliotis/diffuse sclerosing osteomyelitis (DSOM) and proliferative periostitis were categorised under BFOL.

Figure 30.6 is an OPG of a 11-year-old child who presented with recurrent pain and swelling left side body mandible. OPG shows a diffuse ground glass appearance, with changes in the trabecular pattern on the whole of the left ramus and body mandible. A provisional diagnosis of DSOM can be made. Unfortunately, the patient didn't report for further investigations. OPG is included to demonstrate the alteration of the trabecular pattern.

#### **30.4 Ossifying Fibroma/Cementifying Fibroma/Cemento-Ossifying Fibroma (COF) and Juvenile (Aggressive)- Ossifying Fibroma**

#### **30.4.1 Clinical Features**

These were traditionally a group of Fibro-osseous lesions with neoplastic tendencies. COF has had its own share of controversies, being included previously under BFOLs. The recent update in 2018; however, accepts COF as odontogenic in origin and had been placed under mesenchymal odontogenic tumours [19]. Another entity with a similar clinical picture is central odontogenic fbroma, which is also under benign mesenchymal tumours. Lesion that produces cementum including COF and cementoblastoma, thus, currently has found a new place.

In 2017, the consensus group felt that the term cementoossifying fbroma is suitably descriptive and indicates that these lesions are specifc to the tooth-bearing areas of the jaws and can be distinguished from the two juvenile variants of ossifying fbroma. This clearly distinguishes it from ossifying fbromas that are non-odontogenic and are classifed under benign fbro- and chondro-osseous lesions. The three variants are, therefore, defned as cemento-ossifying fbroma, juvenile trabecular-ossifying fbroma and juvenile psammomatoid-ossifying fbroma [20–22].

COF progressive painless buccal and lingual plate expansion. COF affects dentate segment of mandible and maxilla.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 30.4** (**a**) Clinical image of swelling left upper buccal alveolus in a 14-year-old boy. (**b**) Axial CT image showing fecks of radiopacities. (**c**) Shows the lesion exposed, note the gritty nature, which could be

They are slow growing in nature in adults, but show aggressiveness in the younger age group. The teeth are generally displaced. Ossifying Fibromas demonstrate a well delineated or encapsulated cellular fbrous connective tissue with varying amounts of osseous products like bone and cementum (spherical calcifcation).

Lesions are more commonly seen in mandible (77%) especially the molar region and are found exclusively in jaws. The peak age is 3rd and 4th decades of life and very strong female pre-dilection (almost 5:1). The juvenile variant (Juvenile-Ossifying Fibroma), which is also more aggressive, is seen in the younger age group [23].

easily shelled out with relative ease, in this case. (**d**) Intra-operative image where the lesion was shaved out from the alveolar bone via a mucoperiosteal fap approach

#### **30.4.2 Radiological Features**

It is a well-demarcated radiolucent lesion, in the initial stages, separated from the surrounding healthy bone. Usually, a solitary lesion and is unilocular. The well-demarcated radiolucent/radiopaque appearance is the main differentiating consideration with Fibrous Dysplasia. Appearance is dependent on the maturity of the lesion, i.e. purely radiolucent (initial stages); mixed with radiopaque foci or radiopaque. The radiographic presentation of bowing of mandible with thinning and weakening of the lower border, particularly in large expansive lesions, is seen. Resorption or divergence of roots may result due to continued growth.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 30.5** (**a**, **b**) OPG ant coronal CT cuts show evident changes in the right ramus of a 10-year-old girl, who presented with progressing facial asymmetry on the right side ramus region. The provisional diagnosis was of FD, but the bone biopsy (**c**) report was suggestive of sclerosing osteomyelitis

#### **30.4.3 Histologic Features**

Ossifying fbromas of craniofacial skeleton are divided into two categories depending on the cell of origin.

	- 1. Juvenile trabecular-Ossifying Fibroma (JTOF)
	- 2. Juvenile Psammomatoid-ossifying fbroma (JPOF)

#### **30.4.4 Treatment and Prognosis**

COF is a slowly growing benign neoplasm commonly seen in the 3rd to 4th decades of life, if left untreated can enlarge to a signifcant size. Since it is radiographically as well as microscopically well circumscribed and shells out from the surrounding bone with little effort, it is curettage or enucleation a preferred initial treatment option. An important feature is, it is well defned and can be easily shelled out from the adjoining normal bone, grossly the lesion can be separated out in one piece or a few large chunks. The recurrence rate is variable and unpredictable. Surgical curettage is an **Fig. 30.6** OPG in a 11-year-old child showing the diffuse change in the trabecular pattern at the left body/ramus region of mandible

©Association of Oral and Maxillofacial Surgeons of India

**Table 30.1** Comparing the main features of JTOF and JPOF (adapted from Speight and Carlos [9])


acceptable trteatment [27]. Lesions exhibiting more aggressive behaviour and recurrence may need to undergo resection. The anatomical location and age of the patient and aggressiveness of the lesion have a role in deciding the treatment modality of the lesion.

*Clinical case scenario 5* (a case of COF affecting the right side body of the mandible) (Fig. 30.8a–e).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 30.7** (**a**, **b**) Coronal and panoramic CT views in a 26-year-old man with long-standing swelling of the left side maxilla and cheek bone—the case of JOF—lesion flls the left hand side of the nose and paranasal sinuses

623

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 30.8** (**a**) Swelling rt body mandible in 29-year-old female, clinical picture. (**b**) Panoramic image of the CT scan. (**c**) Axial CT image showing the bone destruction. (**d**) Surgical bed after excision of the lesion. (**e**) Cut section of the fbrous lesion

#### **30.5 Cemento-Osseous Dysplasia (Osseous Dysplasia)**

Osseous dysplasia is a non-neoplastic, commonest, least understood fbro-osseous lesion occurring in tooth-bearing areas of the jaws. The cause of misunderstanding lies at the similarities shared at the clinical and histological levels with other fbro-osseous lesions like fbrous dysplasia and ossifying fbroma and even few neoplasias [28].

Since these lesions lie in close association with the periodontal ligaments of the tooth-bearing segment of the jaws, and histopathologically as well, they bear close similarity with PDL, the strong suspicion of the origin in PDL cannot be ruled out.

Two main types are recognised, based on the clinical and radiological features.


Localised variety includes

(a) Periapical cemento osseous dysplasia (PCOD)

(b) Focal cemento osseous dysplasia (FCOD)

Generalised variety includes Florid cemento osseous dysplasia

Ideally, these lesions can be identifed clinically and radiographically without the need for the biopsy, as the presentation is pathognomonic

Su et al. in 1997 have published a series of 316 cases to distinguish the clinical, radiological and pathological features of the cement osseous dyplasias [29, 30].

#### **30.6 Periapical Cemento-Osseous Dysplasia**

#### **30.6.1 Clinical, Radiological and Histological Presentation**

The clinical and radiographic presentation of PCOD is well established. There is a marked predilection for females (14:1) and Afro-Caribbean women [2], and commonly seen in and around the third decade of life, rarely before the age of 20.

Predominantly involves periapical region of anterior mandible, frequently involving more than one tooth at a time though solitary lesions may be occasionally seen.

These are non-expansile asymptomatic lesions and teeth in association are invariably vital and are discovered accidently when radiographs are taken for other purposes.

Radiographically, maturation of the lesion can be appreciated, when examined at various stages.

Initially, they appear as periapical radiolucencies, which can be easily mistaken for a periapical cyst or a granuloma.

Over a period of time, the mixed radiolucent radiopaque picture may emerge and as the lesion matures further, eventually show dense periapical calcifcations at the end stage, which is surrounded by a narrow radiolucent rim. The lesions seldom reach beyond 1–1.5 cm diameter and growth is selflimiting. The lesions remain separated from the periodontal ligament of the tooth throughout their growth phase.

The histological features are coincidental with radiographic fndings and categorised as three stages.

Stage 1: Osteolytic stage/Radiolucent phase


Stage 3: Mature stage/radiopaque phase

Consolidation of bone- or cementum-like tissue.

#### **30.7 Focal Cemento Osseous Dysplasia**

For several years, pathologists were aware of the lesions occurring in the mandibular posterior region, often occurring in the tooth-bearing areas and in relation with recently extracted teeth sockets. Waldron recognised them to be, localised fbro-osseous cemental lesions, supposedly reactive in nature. The present understanding of these lesions is hard work of Summerlin and Tomich, besides naming them as Focal cemento osseous dysplasia, they clinically defned them for a better understanding and differentiation from other lesions especially Ossifying Fibroma [31].

#### **30.7.1 Clinical, Radiological and Histopathological Features**

Focal osseous dysplasia is more commonly seen in Afro-Caribbean females. Male to female preponderance is 1:8. Mainly occurs in the 4th to 5th decades of life with 38 years being an average age of occurrence.

The lesion appears as painless, non-expansile, localised condition especially in posterior mandible, both toothbearing areas as well as edentulous mandible where tooth was extracted in the recent past. A clinical, radiographic and histopathological differential diagnosis of Focal osseous dysplasia is Ossifying fbroma. Since both are more common in posterior mandible and may appear as radiolucent, mixed or radiopaque, well-circumscribed lesions, the clinical and radiological differentiation can be confusing provided one notices the centrifugal growth pattern of and focal osseous dysplasias barely grow beyond 1.5 cm. Radiographically, focal osseous dysplasias tend to be well defned with slightly irregular borders.

On histological examination, one fnds connective tissue stroma comprising of loose collagen fbers, interspersed with irregular shaped cementoid calcifcations. Free haemorrhage is noticed throughout, intermixed with collagen background.

#### **30.8 Florid Cemento-Osseous Dysplasia**

When the lesions, similar in microscopic and radiographic appearance to Focal cemento osseous dysplasia, are found in more than one location in a mandible or in both the quadrants simultaneously, they are identifed as Florid cement osseous dysplasia. Radiographs displayed a spectrum of sclerotic and ground-glass opacities limited to alveolar processes but not to root apices [32]. Chronic osteomyelitis may infrequently complicate the disease. These cases appear to represent the most exuberant manifestation of reactive fbro-osseous jaw disease. Many times, these diseases are an incidental fnding and patient may be asymptomatic (Figs. 30.9 and 30.10)

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 30.10** OPG of a 55-year-old Asian female who reported for dental extractions due to pain. Xray reveals forid COD-like lesions in both jaws

**Fig. 30.9** OPG of a 73-year-old Asian female, who had x-ray taken for removal of lower right third molar. X-ray shows diffuse forid COD-like lesions

#### **30.8.1 Clinical, Radiological and Histological Features**

Florid cemento osseous dysplasia shows predilection for Afro-Caribbean women in the fourth to ffth decades of life, with a mean age of 42 years. The lesion has a propensity for bilateral symmetrical involvement of mandible. Occasional maxillary involvement is not rare.

The patients are usually edentulous and lesions are usually non-expansible, if cortical expansion is present then it is limited in nature.

The diagnosis of Florid OD is mainly clinical and radiographic, Melrose [32] suggests the involvement of two jaw quadrant is imperative for the diagnosis of Florid COD. Radiographically, the lesion undergoes stages of maturation as seen in the other types of OD, initially, the lesions are mainly radiolucent and with time progressively become frst mixed radiolucent radiopaque and then in later stages turn into radiopaque sclerotic masses. Simple bone cyst that appears as sharply defned radiolucent areas may be intermixed with the lesional tissue, is a frequent fnding in Florid OD. The most commonest radiographic presentation is of multiple sclerotic lobular opacities mixed ill defned with radiopaque radiolucent masses involving the alveolar process of mandible and maxilla sparing the lower border of the mandible and vertical rami.

Histologically, the lesion has similar features like other two forms of OD. The lesion specimen consists of cellular mesenchymal connective tissue, with numerous spindleshaped fbroblasts and blood vessels. Multiple haemorrhagic sites are a common fnding in the connective tissue background along with lamellar-, woven- and cementum-like particles. Depending on the extent of maturation of the lesion, they become more sclerotic and the ratio of fbrous connective tissue to mineralised material decreases.

#### **30.8.2 Treatment/Management**

The modifed osseous tissue is prone to infection, hence any local causes of infection-like periapical pathosis, periodontal disease, ill-ftting dentures can lead to osteomyelitis of the underlying altered bone and fstula and sequestra formation. It is recommended to avoid any surgical intervention for diagnostic purposes, as the diagnosis is generally made on clinical and radiographic presentation. As for the treatment of symptomatic lesions like the presence of underlying osteomyelitis, conservative care in the form of removal of sequestra and prolonged antibiotic therapy is recommended. Extractions are not recommended for the same reason, as the socket heals by replacement with cementum-like tissue, which is mainly avascular.

Surgical intervention in terms of the debulking procedures is only recommended where there is obvious facial deformity resulting in reduced quality of life [33].

#### **30.9 Conclusion**

FOLs form a diverse wide spectrum of lesions, which are still evolving; in their classifcations. Maxillofacial surgeons usually come across intra-oral lesions at various stages and many of them can be managed easily by routine surgical modalities. Certain lesions show aggressive nature and involve mid-face and sino-nasal areas. Such cases will need a multi-disciplinary approach for optimal treatment outcomes. Close interaction with the pathologist and adequate radiological investigations are needed to ascertain the diagnosis in many cases. The lack of clarity in classifcation and the similar radiological and histological picture of various lesions add to the diffculty in reaching a diagnosis.

**Acknowledgments** Suvy Manuel for Figures 30.1, 30.2, 30.3, 30.4, 30.5, 30.6, and 30.9 Oommen A Jacob-Figures 30.7, 30.8

Sooraj S- Figure 30.10

#### **References**


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## **Vascular Anomalies of the Oro-Maxillofacial Region**

Sanjiv Nair and Sunil S. Shrof

# **31**

### **31.1 Introduction**

Vascular anomalies are lesions arising from the arterial and/ or venous and/or lymphatic circulation. These have a wide array of histological and clinical features and constitute one of the commonest congenital anomalies in infants and children [1].

In the context of iatrogenic creation of arteriovenous fstulas by phlebotomists, William Hunter in the mid-eighteenth century frst described vascular anomalies. Haemangiomas and vascular malformations are different entities of vascular anomalies and this was frst recognised by James Wardrop in 1818 [2]. In spite of Dr. Wardrop's work, subjective words like 'strawberry hemangioma' and 'salmon patch' were used for a long time. These terms only refected the appearance and did not correlate clinically or histologically [2].

Anomalies presenting in different age groups with varying clinical behaviours needing different treatments were often given the same or overlapping names by clinicians. Commonly used terms are: haemangioma, arterial malformation, venous malformation, capillary malformation and lymphatic malformation.

Haemangioma (Figs. 31.1 and 31.20): Is a benign tumour of blood vessels comprising arterioles with endothelial cells, which are proliferative and hyperplastic in nature.

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**Fig. 31.1** Non-involuting congenital Haemangioma (NICH) of left cheek ((**a**) initial therapy with propanolol 10 days post-birth, (**b**) 6 months following propanolol therapy, (**c**) excision of lesion at 2 years age)

S. Nair (\*) · S. S. Shroff (\*)

Department of Oral and Maxillofacial Surgery, Bhagwan Mahaveer Jain Hospital, Bengaluru, Karnataka, India

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_31

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 629

This terminology has been used by many as a common term for any vascular anomaly especially in childhood. These develop within the initial few weeks of life but often resolve with time. It is necessary for one to be able to differentiate between haemangioma and other vascular anomalies.

Arterial malformation (Fig. 31.2): These are dilated, overlapping and tortuous arteries having a coil-like appearance and/or a collection of arterial loops without any venous component. They are also described as 'high fow lesions'.

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**Fig. 31.2** Arterial malformation ((**a**, **b**) tongue high fow lesion, (**c**) DSA, (**d**) embolisation)

Venous malformation (Fig. 31.3): These are commonest type of vascular malformations caused by ectatic venous channels, also called 'low fow lesions'.

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Capillary malformations (Fig. 31.4): These are commonly known as, *'port wine stain'*. It is a fat, well-defned vascular stain of skin seen early in development when vessels of skin form abnormally which can increase in size and give a nodular appearance as a late presentation.

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**Fig. 31.4** Capillary malformation of lower lip, chin and right cheek

Lymphatic malformation (Fig. 31.5a, b): These are lesions containing fuid-flled spaces or channels, thought to be caused by abnormal development of the lymphatic system.

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**Fig. 31.5** (**a**) Micro-cystic lymphatic malformation of tongue ((i) coronal T2 weighted MRI image, (ii) pre-operative clinical). (**b**) Axial post-contrast image of macro-cystic lymphatic malformation of left Parotid. Copyright: Authors own publication from IJOMS 2018

The above lesions in different combinations make up for 'arteriovenous' (Fig. 31.6) and 'lymphovenous' malformations.

#### **31.2 Pathogenesis**

Histologically, vascular anomalies are seen as a localised increase in vasculature with abnormal tortuosity and enlargement. This is known to be caused by defects in the formation of these vessels during vasculogenesis [3].

'Vasculogenesis' is defned as growth of vessels from precursor cells like, haemangioblasts that further give rise to angioblasts and haemocytoblasts.

Fusion takes place in islands of vasculature leading to the formation of primary capillary plexus, which then extends and matures during angiogenesis. This involves the proliferation of endothelial cells and the recruitment of mural cells to form fully developed and functional lymphatic and vascular trees [4].

Angiogenesis is regulated by factors like VEGFs (vascular endothelial growth factors), FGFs (fbroblast growth factors), PDGF-beta (platelet derived growth factor beta) and ANGPT-1 and ANGPT-2 (angiopoietins). These factors cause activation of precursor cells, leading to migration, proliferation and differentiation of the primary capillary plexus [5].

VEGFs, angiopoietins, and their endothelial tyrosine kinase receptors are known to be the central regulators of vasculogenesis, angiogenesis and lymphangiogenesis [4].

**Haemangiomas** have currently 2 dominant theories [6], although unclear. These are:


Abnormal levels of matrix metalloproteinases (MMP9) and proangiogenic factors (VEGF, b-FGF and TGF-beta 1) are involved in the pathogenesis of haemangioma. Genetic errors involving growth factor receptors are also known to infuence the development of these lesions [6].

There are 3 stages in the life cycle of haemangiomas [7], each characterised by biological markers and processes. These stages are clinically seen and distinguished microscopically and immunohistochemically [8] as,


**Fig. 31.6** Arteriovenous malformation of pinna of right ear ((**a**, **b**) previous Popescu suturing as reported, (**c**) coronal CT angiography image, (**d**) contrast MR angiography image). Copyright: Authors own publication from IJOMS 2018

634

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#### **Fig. 31.6** (continued)

**Venous malformations (VMs)** are known to be autosomally dominant showing high penetrance. Abnormal venous connections cause venous congestion, thrombosis and slow expansion of these lesions. VMs commonly have a sporadic occurrence, but research has suspected a genetic locus to be involved in their development [6]. Chromosome 9p has been localised to cause inherited forms of VMs. The loss of functional mutation on the angioprotein-receptor gene TIE2/TEK and upregulation of many factors like tissue growth factor beta (TGF-beta) and basic fbroblast growth factor (beta-FGF) is seen [6]. Progesterone receptors are also found in VMs, which explains their propensity to enlarge rapidly during hormonal changes.

The pathogenesis of *capillary malformations (CMs)* is not clearly understood. These can be seen anywhere on the body, localised to a dermatome or extensive in nature. A familial pattern has been identifed with a locus on chromosome 5q in a genome-wide linkage analysis [9].

**Lymphatic malformations (LMs)** show a focal pattern of occurrence. The aetiology is not clearly understood. Although most cases are congenital, there is no evidence of associated familial pattern. There have been cases of LMs following trauma or infection. Receptors like VEGFR3 and Prox-1, likely play a role in their development [10].

The pathogenesis of *arterio-venous malformations (AVMs)* is also not clearly understood. A defect in vascular stabilisation is known to potentially cause AVMs. Intracranial AVM is seen most commonly, followed by AVMs involving extracranial head and neck, extremities, trunk and viscera. These are seen at birth and are frequently misdiagnosed as a CM or haemangioma. These lesions have been seen following trauma in adults. Defects in signalling of TGF-Beta and genetic two-hit hypothesis are the existing theories [11, 12].

#### **31.3 Classifcations**

Mulliken and Glowacki [13] in 1982 introduced a biological classifcation, which classifed vascular lesions into two distinct entities: haemangiomas and vascular malformations.

Haemangiomas demonstrate endothelial hyperplasia unlike vascular malformations, which show progressive dilatation of abnormal vessels lined by fat endothelium on a thin basal lamina. A more practical classifcation amalgamating their biological behaviour and fow dynamics was later introduced [14] (Table 31.1).



**Table 31.2** International Society for the study of Vascular Anomalies classifcation system (ISSVA) [15]


This system was later revised and adopted by the ISSVA [15] (*International Society for the study of Vascular anomalies*). This is currently the most widely accepted and divides vascular anomalies into: vascular tumors and vascular malformations (Table 31.2). The online version of the classifcation, is available on the ISSVA website (www.issva.org), contains hypertext links that facilitate the navigation in the classifcation and its appendices. These vascular neoplasms show an increased turnover of endothelial cells, which undergo division by mitosis, unlike vascular malformations. Vascular malformations can be capillary, venous, lymphatic and arterial, which progress in proportion to the child.

We proposed a practical classifcation of vascular lesions based on anatomy and depth of location in the head and neck region [1] (Table 31.3), which helped not only in understanding the extent of lesion but also in determining the surgical approach and reconstruction necessary. This classifcation is found to be most useful for the surgical management of these complex lesions.

**Table 31.3** Anatomical classifcation of Vascular malformations [1] (IJOMS 2011: 40)


Type-I lesions (Fig. 31.7) are superfcial involving the epidermis and dermis. These can be excised in toto and reconstructed with local faps where necessary. Lasers have some use in such surface lesions.

Type-II lesions (Fig. 31.8) involve sub-cutaneous tissue and facial planes. These can be widespread sometimes and approached by meticulously raising a superfcial skin fap. The lesion is either debulked, excised or corseted as necessary (discussed in surgical management).

Type-III lesions (Fig. 31.9) are deeper involving salivary glands, usually parotid and sub-mandibular, demand-raising faps in sub-cutaneous and sub-dermal planes. The lesion is either debulked, excised or corseted as necessary (discussed in surgical management).

Type-IV lesions (Fig. 31.10) involve bone and are either curetted or excised followed by reconstruction. These are usually high-fow lesions and require ECA control or endovascular embolisation to achieve adequate haemostasis (intra-operative dye administration in Fig. 31.10 demonstrates the effcacy of intra-operative ECA control in treating such high-fow vascular lesions).

Type-V lesions (Fig. 31.11) involve deeper visceral spaces like parapharyngeal, retropharyngeal, glottis and laryngeal. These can be rarely excised intoto and require access osteotomies of maxilla, mandible or zygoma (see Chap. 85 on access osteotomies).

#### **31.4 Clinical Findings** (Table 31.4)

A comprehensive and holistic understanding of the true nature of lesion is important to adequately manage these patients. The different types will be discussed according to the ISSVA classifcation for simplicity here, while the surgical management will be discussed according to the anatomical classifcation, as it was found to be more helpful than other available classifcations.

Superfcial *haemangiomas* (Fig. 31.20) can appear as raspberry-coloured birthmarks or reddish discolouration of the skin. The bright red strawberry-like classic appearance may not be seen in deeper lesions involving sub-cutaneous tissues. These deep lesions are wrongly diagnosed as vascular malformation, with normal appearing overlying skin. Superfcial lesions were previously called 'capillary hemangiomas', and deeper lesions 'cavernous hemangiomas'. These terms do not refect the clinical nature or infuence the

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**Fig. 31.7** Type-I vascular lesion ((**a**) pre-operative tongue VM, (**b**) debulking, (**c**) closure and (**d**) post-operative). Copyright: Authors own publications from IJOMS 2011

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**Fig. 31.8** Type-II vascular lesion ((**a**) pre-operative Left cheek VM, (**b**) incision, (**c**) exposure and excision and (**d**) Post-operative)

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**Fig. 31.9** Type-III vascular lesion ((**a**) pre-operative Left parotid AVM, (**b**) incision, (**c**) exposure, (**d**) facial nerve dissection, (**e**) excision specimen and (**f**) post-operative). Copyright: Authors own publications from IJOMS 2011

treatment and should be reserved only for histological description. Compound lesions involving superfcial and deeper tissues are also seen. The clinical appearance may vary depending on the depth of tumour. Growing haemangiomas can show organ involvement and cause ulcerations, bleeding, hearing problems, vision changes, diffculty in mastication, dysphagia and dyspnea.

Congenital haemangiomas are further divided into infantile haemangiomas (IHs), rapidly involuting congenital haemangiomas (RICHs), non-involuting congenital haemangiomas (NICHs) and partially involuting congenital haemangiomas (PICHs) [15, 16].

IHs are commonly seen in infants and occur in 5–10% of children [17]. They appear anywhere between a few days to 3 weeks after birth. 80% of these cutaneous lesions are single and 20% are multiple. They grow rapidly and then enter an inactive phase at about 6 months of age. They then begin to shrink and involute after 1 year of age and sometimes leave behind a residual lesion. These residual lesions take longer to resolve.

RICHs (Fig. 31.20) are present at birth and involute by 6–14 months of age. Occasionally, they cause haematological irregularities like the Kasabach-Merritt phenomenon (KMP).

NICHs (Fig. 31.1) are present at birth and get larger with age. It is best to wait until 1 year of age to differentiate between RICH and NICH by looking at the involution pattern. PICHs initially present as RICH but fail to involute completely and remain as NICH.

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**Fig. 31.10** Type-IV vascular lesion ((**a**) pre-operative AVM right mandible, (**b**) axial post-contrast CT image, (**c**) ECA control and injection of radiopaque dye, (**d**) intra-operative C-arm picture following dye

injection before occluding of ECA, (**e**) intra-operative C-arm picture following dye injection and occlusion of ECA, (**f**) lesion exposure and (**g**) currettage of lesion)

**Fig. 31.11** Type-V vascular lesion ((**a**) pre-operative VM left parotid, (**b**) parapharyngeal extension, (**c**) coronal T1 weighted MRI image, (**d**) exposure, (**e**) lesion exposure with mandibulotomy and ECA control,

(**f**) lesion complete currettage, (**g**) mandibulotomy closure and (**h**) postoperative). © Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 31.11** (continued)


**Table 31.4** Clinical fndings of Vascular anomalies of Head and Neck

**Venous malformations (VMs)** (Fig. 31.3) are most commonly seen vascular malformations, which are slowgrowing, low-fow lesions present at birth and demonstrate a network of serpiginous inter-woven veins. These can grow extensively, become palpable, discoloured or bluish in colour with local blood stasis, which sometimes lead to painful thrombophlebitis. VMs can increase in size, in proportion to the increase in pressure within vessels caused by valsalva manoeuvre, dependency, exercise or agitation. VMs are usually compressible on palpation. They can demonstrate 'pheboliths', which are nothing but small calcifcations formed due to, prolonged intra-vascular coagulation (Fig. 31.12).

Phleboliths are the commonest cause of pain in VMs. There is progressive lamellar fbrosis following intravascular thrombus formation. Calcium phosphate and carbonate are deposited in the core of the thrombus with peripheral mineralisation [18], which slowly increases in size. They are clinically palpable intra-orally, bi-manually in the cheek and over bony prominences. These are present as multiple oval or round laminated bodies (Fig. 31.12) with radiolucent or radiopaque corners, radiologically. Phleboliths can be areas of resistance to injecting sclerosants and should be excised separately.

**Capillary malformations (CMs)** (Fig. 31.4), can be seen in the neonatal period and should not be mistaken with infantile haemangiomas (IHs). They occur in around 0.3% of children presenting with vascular anomalies. CMs usually present congenitally as a fat, red or purple cutaneous patch with asymmetric borders. They are painless and do not bleed spontaneously. They are categorised as 'medial' or 'lateral' lesions, based on their location in head and neck. Lateral lesions involve areas of face along the distribution of trigeminal nerve. They present as portwine stains, usually increase in size to involve deeper sub-cutaneous tissues causing the lesions to become darker, more raised and nodular. CMs may be part of a syndrome, commonly the Sturge-Weber syndrome, which is characterised by CM involving the ophthalmic branch of trigeminal nerve, leptomeningeal angiomatosis and choroid angioma. CMs may also be seen in the Klippel-Trenaunay syndrome with multiple vascular (lymphatic, venous and capillary) abnormalities.

**Lymphatic malformations (LMs)** (Fig. 31.5) are usually congenital and not always detected until later in life. LMs are slow-fow lesions and can be *macro-cystic* (>2 cm) (Fig. 31.5b), *micro-cystic* (<2 cm) (Fig. 31.5a) or *mixed*, depending on the size of predominant cysts within them. Macro-cystic LMs can show expansion and compression of adjacent anatomical structures in the head and neck causing dysphagia, dyspnea and masticatory problems. Micro-cystic LMs were previously called lymphangiomas and demonstrate an infltrative nature. LMs with local haemorrhage and infection can cause signifcant pain. LMs of the head and neck are further described by the *de Serres classifcation scheme* [19], which classifes disease severity based on the location and prognosis.

Fast-fow *arterio-venous malformations* (AVMs) (Fig. 31.6), usually present with a pulsatile local swelling. These AVMs along with some slow-fow lesions are at an increased risk of haematological complications like coagulopathies due to disturbances in haemostasis and thrombosis. Blood pools in abnormal slow-fow vessels, resulting in activation of the coagulation system, resulting in a process known as 'localized intravascular coagulopathy' (LIC), which shows low fbrinogen, elevated D-dimer levels and mild thrombocytopaenia. This can further cause, 'disseminated intravascular coagulopathy' (DIC) and consumption of various coagulation factors.

AVMs are known to behave aggressively in later life, which can be stimulated by pubertal changes, pregnancy or trauma. They may present with throbbing pain, ulceration

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**Fig. 31.12** Left cheek and lower lip VM ((**a**) clinical picture, (**b**, **c**) post-contrast axial and sagittal CT images showing multiple phleboliths)

and bleeding. Signifcant bleeding can sometimes be a cause of cardiac failure, in affected individuals.

A useful clinical staging system was introduced by Schobinger [20] in 1990. This system is widely used for describing the clinical presentation and evolution of AVMs: *Stage I* (quiescence): pink-bluish stain, warmth and arterio-

venous shunting by way of Doppler examination

*Stage II* (expansion): same as stage I, plus enlargement, pulsations, thrill, bruit and tense/tortuous veins


Undiagnosed AVMs of bone are occasionally the cause of increased bleeding during/after extraction of teeth in a dental offce, which can lead to life-threatening airway and haematological problems if not treated immediately (Fig. 31.13). These warrant urgent transfer to a hospital and embolisation or ECA control.

Hereditary haemorrhagic telangiectasia (HHT) is autosomally dominant and presents with the formation of expanding arterio-venous fstulas. These patients usually present with superfcial (skin, mucosal) or deep (visceral) telangiectatic lesions. They may sometimes present with aneurysms causing epistaxis or intra-cranial haemorrhage.

Kaposiform haemangioendotheliomas (KHEs) are large lesions (greater than 5 cm), which are present in the neonatal period. They are extremely rare and have a low incidence of occurrence. Hence, there are no clear guidelines on their management. These are aggressive vascular tumours, which can be complex in their management due to thrombocytopaenia secondary to platelet trapping. This phenomenon is known as KMP (Kasabach-Merritt phenomenon). 70% of patients with KHEs demonstrate this phenomenon [21].

#### **31.5 Radiological Assessment**

Clinical and radiological assessment go hand in hand to accurately diagnose and manage these diverse groups of head and neck vascular anomalies. Selection of the imaging should be tailored according to the indication, advantages, disadvantages and availability of resources. Good knowledge of all the available radiological modalities is essential to treat these lesions.


**US** (Fig. 31.14) is the least invasive modality of imaging available for assessment of vascular anomalies. It is used as a baseline investigation for superfcial head and neck vascular lesions. In addition to the above, the US has a high sensitivity in diagnosing these lesions. The disadvantages of the US are its limitation in detecting deeper soft tissue and bony lesions.

**Doppler ultrasound** (Fig. 31.15) is used to demonstrate high-fow lesions. Flow towards the ultrasound transducer is seen in red and away from the transducer seen in blue. The arterial feeder is usually identifed by increased colour fow, high doppler shift and low resistance.

**CT** (Fig. 31.16) is used to diagnose bony lesions, provide cross-sectional details and detect the presence of calcifcations like phleboliths in venous malformations and haemangiomas. Most scans can be done in less than a minute with quick acquisition time. Reduced imaging time and low cost compared to MRI make contrast CT widely used for diagnosing soft tissue vascular lesions. Surveillance imaging with CT is not recommended due to increased exposure to ionising radiation.

**MRI** (Fig. 31.17) is the most preferred and accepted imaging for diagnosing and monitoring soft-tissue vascular lesions of head and neck. Its superior contrast resolution, indepth soft-tissue assessment and non-exposure to ionising radiation, makes it the investigation of choice for these lesions. Haemangiomas and VMs show intense enhancement with MRI. AVMs and LMs show minimal enhancement.

Fat-suppressed T2-weighted imaging is used to discriminate these lesions among each other. Intense T2-weighted signal is seen with VM's and macro-cystic LM's due to cystic spaces within them and pooling of slow-fowing blood or lymph. Moderate signal intensity is seen with haemangiomas and vascular neoplasms due to their cellular composition. Mild T2-weighted signal is seen with AVM's refecting tissue oedema.

Long acquisition time (at least 30 min) and increased cost of imaging limit its use [22]. Use of sedation or anaesthesia is required for infants, children and uncooperative adults.

**Angiography** (Fig. 31.18) is usually reserved for therapeutic endovascular interventions. Angiography includes arteriography, venography and injection of direct intralesional contrast agent. This provides good resolution (spatial and temporal) of the vascularity and also permits catheter-induced percutaneous therapy. Arteriography is used for the evaluation of high-fow vascular lesions. Its use is limited due to the invasive nature and use of ionising radiation.

**DSA** (Fig. 31.19) should be reserved for patients undergoing endovascular treatment. DSA is used for diagnosis of AVM's where the feeding artery, draining vein, nidus connecting artery and vein can be clearly imaged [23] and simultaneous embolisation can be performed, by an interventional radiologist.

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**Fig. 31.13** Bleeding following dental extraction—Extracorporeal currettage of high-fow bony vascular lesion and fxation of mandible ((**a**) pre-operative, (**b**) intra-oral, (**c**) ligation of main feeder, (**d**) extra-cor-

poreal currettage and excision of diseased bone and (**e**) fxation of mandible as the free graft)

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**Fig. 31.14** Ultrasound image-Venous malformation of submandibular region showing multiple cystic spaces

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**Fig. 31.16** CT with contrast, Right mandible Type-IV lesion

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**Fig. 31.15** Coloured Doppler Ultrasound image of AVM of neck showing multiple cystic spaces flled with colour (fow towards the transducer seen in 'red' and away in 'blue', lighter shades of colour depict higher velocity)

Multi-planar dynamic contrast-enhanced MRI is preferred for extensive vascular malformations of the head and neck, especially in lesions involving aerodigestive tract, neural and vascular structures.

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**Fig. 31.17** T2-weighted MRI, left parapharyngeal venous malformation

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**Fig. 31.18** AVM of right mandible ((**a**) Contrast MR angiography image, (**b**) T2-weighted MRI image). Copyright: Authors own publications from IJOMS 2011

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 31.19** AVM left cheek ((**a**) clinical image, (**b**) DSA image during embolization)

#### **31.6 Medical and Interventional Management**

Correct diagnosis is important for selecting the appropriate therapy for vascular anomalies.

The aim of managing complex vascular lesions should be to relieve acute symptoms like pain, swallowing and airway problems, prevent and treat thromboembolic events and correct the cosmetic impairment caused by them.

The type of vascular anomaly and its fow characteristics, determine the mode of management.

These mostly fall into:


Congenital haemangiomas, low fow venous malformations and lymphangiomas can be considered for treatment with systemic and sclerotherapy. Residual and large lesions are usually treated with surgery. AVM's and high-fow malformations have been mostly treated using embolisation with or without surgical excision/debulking successfully.

The author's wide experience in the surgical management of most low- and high-fow lesions has provided acceptable and predictable results.

In *haemangiomas*, a '*wait and observe'* strategy is preferred. Involution is seen in more than 85% of patients. If a malignant lesion is suspected, a biopsy with a request for GLUT-1 immunostaining is required to confrm its true nature [24]. Active intervention is considered if the lesion is


**Propranolol** (Fig. 31.20) is the frst line of treatment and is best to involve a paediatrician to monitor the dosage and systemic complications associated with it. Propranolol causes vasoconstriction and possibly reduced expression of pro-angiogenic factors of the haemangioma growth phase, leading to apoptosis of capillary endothelial cells.

Treatment during the proliferating phase is given to prevent impending functional or aesthetic complications especially

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**Fig. 31.20** Rapidly involuting congenital Haemangioma (RICH) of right face treated with propanolol therapy ((**a**) pre-treatment, (**b**) post-treatment)

near vital areas like eyes and ear. In the absence of contra-indications to propranolol like sensitivity to beta-blockers, bronchospasm, hypotension or bradycardia and after having a routine haematological and biochemical assessment by the paediatrician, a dose of 1 mg/kg/day in three divided doses may be initiated and titrated up to 2 mg/kg/day. This is given for 12 months or longer according to the response. Meticulous dose adaptation is important to prevent adverse effects. These could be bradycardia, increased airway resistance, bronchial obstruction and hypotension.Long-term effects of propranolol are still not known and other drugs like timolol have been tried for superfcial and peri-ocular lesions. Invasive therapies are almost never required to treat these lesions.

Although propranolol has replaced the use of *systemic steroids* as the frst line therapy for haemangiomas, intralesional therapy for localised lesions with, Triamcinolone may be used with a dose of 2 mg/kg every 4–6 weeks depending on the response. It is known that one-third of patients do not respond to treatment with steroids. Systemic steroids are sometimes given in conjunction with propranolol after consulting with the paediatrician.

Rebound growth being a problem with systemic therapy using propranolol and/or steroids, the dose is always preferred to be tapered-off before discontinuing following resolution of the lesion.

Embolisation is considered in patients with high-output cardiac failure and large-aggressive lesions causing problems with haemostasis.

Surgery is considered between 2 and 4 years of age after having attempted medical treatment to minimise deformity involving eyes, nose and lips and other areas of face.

Pulsed dye laser was used in past for coagulating the surface of ulcerated lesions. This is now used for the treatment of surface residual telangiectasia, usually after 10 years of age (Algorithm 31.1).

**Minimally invasive percutaneous sclerotherapy** is used widely for the treatment of venous malformations. A wide range of agents are known to be used in the literature. There is no consensus on choice of sclerosant to be used. Commonly used sclerosants [25] are pingyangmycin (PYM), absolute ethanol, OK-432 (picibanil), ethanolamine oleate, bleomycin, polidocanol, doxycycline and STS (Sodium tetradecyl sulphate).

**PYM** [25], also known as Bleomycin A5, is the most commonly used single-drug therapy for the treatment of cervicofacial malformations. Transient fever and swelling are commonly seen side effects. Skin ulceration and subcutaneous tissue atrophy are scarcely seen complications.

**Absolute ethanol** [25] causes alteration in cellular proteins and hence damages the endothelium of the vascular wall leading to obliteration of its lumen. Common complications include, nerve injury, necrosis and ulceration of skin.

**OK-432** [25] is a lyophilised preparation of low-virulence bacteria, group A Streptococcus pyogenes, incubated with

**Algorithm 31.1** Management of Haemangioma

benzyl- penicillin. It causes, induction of various cytokines. The infammatory response caused by this remains localised and causes endothelial damage. The complications include local swelling and transient facial nerve palsy.

**Ethanolamine oleate** [25] is an emulsion of fatty acids, which induces thrombosis and damages the endothelium. Complications like ulceration and necrosis of skin are known but infrequently observed.

**Bleomycin** [25] was frst used in the treatment of cystic hygromas (now lymphatic malformation). It is now used widely for management of lymphatic and venous malformations. It inhibits DNA synthesis and has a non-specifc infammatory reaction on the endothelial cells. Adverse effects of bleomycin are minimal and transient, mostly being localised pain and swelling. Skin infections in the area of injection are seen less commonly. Some people report with occasionally severe nausea.

**Polidocanol** [25] is a non-ionic detergent, causes absorption at the cell membrane and leads to lysis of endothelial lining. Superfcial necrosis of skin or mucosa is a known complication with Polidocanol.

**Doxycycline** [25] belongs to the tetracycline group of antibiotics. Its mode of action is not yet clear, but its effects are known to be due to inhibition of matrix metalloproteinases and cell proliferation. It also causes suppression of vascular endothelial growth factor during angiogenesis and lymphangiogenesis. This further leads to dense adhesions and fbrosis due to collagen and fbrin deposition. Macrocystic LM's show a better response to treatment with doxycycline in comparison to micro-cystic LM's. Haemorrhage, cellulitis, pain and transient oedema are commonly seen complications. Scarring, skin excoriation and horner syndrome are seen less commonly. These adverse effects are self-limiting and likely to be related to the sclerosing effect rather than a side effect of the medication itself.

**STS** [25], also known as *sotradecol*, causes denaturation of proteins like clotting factors due to disruption of the normal architecture of the lipid bilayer in cell membranes of endothelial cells. This causes fbrosis and occlusion of vessels. It is not known to have any major complications so far.

*Lymphatic malformations* are treated depending on the type and location in head and neck. As mentioned previously, these lesions can cause pressure on the airway, aerodigestive tract and enlarge due to repeated infection or haemorrhage into the lesion. In the majority of patients with macro-cystic LMs, sclerotherapy with *Picibanil (OK-432)* has shown good results. Patients may develop infammation at the site of injection and fever, which is managed symptomatically. Micro-cystic LMs may require systemic therapy with *Sirolimus* or surgery as they do not always respond to Picibanil. Sirolimus is a natural macrolide secluded from Streptomyces genus (Streptomyces hygroscopicus). It causes a decrease in the vascular endothelial growth factor (VEGF) and is a key regulator in lymphangiogenesis and angiogenesis.

**Bleomycin** is used widely for the treatment of VMs and microcystic LMs. The mechanism of action on micro-cystic disease is not completely understood and may involve derangement of tight junctions between endothelial cells or induction of endothelial mesenchymal transition. The overall response is favourable but complete response is seen in only about 20–57% [25]. The author follows a protocol of intralesional injection of 15 IU Bleomycin in 5 ml of fresh normal saline, administered every 15 days. Most patients show a response in 3–4 sittings (Fig. 31.21). Lymphatic malformations are known to cause sec-

ondary skeletal deformities, which are addressed due to functional or cosmetic reasons as necessary.

**AVMs** are the most challenging type of vascular malformations to manage due to their aggressive nature. They tend to cause progressive facial deformity and pose a signifcant systemic risk. They are high-fow lesions that typically demonstrate a nidus with arterial feeders, arteriovenous connections and enlarged veins. Schobinger's class III and IV demand aggressive management with combined embolisation, surgical excision and reconstructing the residual defect. Trans-arterial and trans-venous catheter angiography are commonly used for assessment, examination of the nidus and location of arterio-venous shunting. A few lesions can be controlled with frequent embolisation. The nidus must be treated to get control over the lesion. *Catheter embolisation causes* obliteration of the nidus in order to prevent a further increase in size and haemorrhagic complications. This can be either *endovascular* (Fig. 31.22) as used for large AVM's with aberrant feeders or *percutaneous* (Fig. 31.23) used for more superfcial lesions. The feeders are sequentially embolised from distant to proximal feeders. Embolisation can be used for pre-surgical occlusion of feeder vessel on the same day of planned surgery to minimise intra-operative blood loss.

Commonly used embolic agents are: Ethanol, Cyanoacrylate (glue), Coils, polyvinyl particles, Onyx—a liquid ethylene vinyl alcohol copolymer.

Kaposiform Haemangioendotheliomas (KHEs) are treated with hematological agents such as *vincristine, steroids or sirolimus*. These systemic medications help in the resolution of KHE and associated KMP (Kasabach Merritt phenomenon). Surgical management of these lesions is usually not required but small lesions can be removed in toto with early intervention.

#### **31.7 Surgical Management**

Unlike in the past, most low- and high-fow vascular anomalies are amenable to surgical management by either excision or debulking. Smaller-sized lesions are almost always excised completely. In contrast, larger-sized lesions are mostly debulked and need multiple procedures. External carotid artery (ECA) control is used to have reasonable control before and during procedures involving high-fow lesions. This is partly because of collateral blood supply from the opposite side.

For simplicity, the author's own anatomical classifcation is followed as it makes the understanding of the surgical approaches and the rationale behind them more lucid and comprehensible. Also, the concept of 'Corset suturing' will be explained, which has been proved to be an asset in management of large low-fow vascular anomalies.

#### **31.7.1 Surgical Anatomy**

An understanding of the different layers and planes of dissection in the head and neck is important to approach and treat these vascular anomalies. The commonest areas involved in the head and neck are cheek, lower and upper lips, eyelids, pre-auricular, mandible, submandibular, submental, upper neck, posterior and lateral oropharynx. The glottis, sub-glottis and lower neck are less commonly involved. Lymphovascular malformations are seen occupying scalp and orbit commonly.

Layers of face from superfcial to deep are—skin, subcutaneous tissue, SMAS layer, parotid fascia (pre-auricular)/ deep cervical fascia (sub-mandibular), salivary gland (parotid and sub-mandibular regions), muscle, periosteum and bone. The scalp has a loose areolar plane and all other tissues attached. The neck has vital structures like the carotid artery, jugular vein, spinal accessory nerve, cervical plexus and other muscles superfcial and deep to them.

#### **31.7.2 Case Selection**

According to the author's classifcation, vascular malformations were categorised into fve types based on their anatomy and depth of location in the head and neck. This is a good guide for selecting the type of surgical management and reconstruction.


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 31.22** Sequential endovascular embolisation of left cheek AVM ((**a**–**d**) progressing blockage of blood supply to AVM, (**e**) 3D reconstructed view of the vascular network)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 31.23** AVM of left supra-orbit ((**a**) pre-operative, (**b**) CT with contrast, (**c**) percutaneous embolisation, (**d**) Surgical excision via haemicoronal approach, (**e**) post-operative)

• Type-V lesions involve deep visceral spaces, such as the parapharyngeal or infra-temporal fossa and usually require mandibular access osteotomy for complete exposure and complete removal of the lesion.

The above procedures can demand either endovascular embolisation, intra-lesional embolisation or ECA control prior to attempting excision or debulking of these lesions.

#### **31.7.3 Technique of External Carotid Artery (ECA) Control** (Fig. 31.24)

The ECA of the involved side is exposed through a cervical incision, which often forms, part of the access for removal of the malformation. The sternocleidomastoid muscle is retracted posteriorly at the level of the greater cornu of the hyoid bone, exposing the carotid sheath. The external carotid distal to the carotid bifurcation is identifed. The vessel is snared with a vascular sling passed through a rubber catheter. Gentle strangulation of the vessel can be accomplished by advancing the catheter. This additional compression of the vessel serves to reduce blood fow to the lesion. In demanding situations, the ECA can be ligated. Many times due to risk of collateral blood supply to these lesions, ECA control is an adjunct to achieving haemostasis along with aggressive local control.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 31.24** ECA control. Copyright: Authors own publications from IJOMS 2011

#### **31.7.4 Corset-Suturing Technique** (Fig. 31.25)

Corset suturing [26] is a proven technique in management of large low-fow venous malformations of head and neck, especially in lesions where complete excision is not practically possible and also those in close proximity to important structures like airway, facial nerve, spinal accessory nerve, internal jugular vein and in medically compromised individuals.

'Corset', is a garment worn to hold and train the torsoin to a desired shape for aesthetic or orthopaedic purposes. The procedure employed is raising a fap in the sub-SMAS or sub-cutaneous plane depending upon the type of lesion followed by placement of a bioresorbable suture (polydiaxanone) that runs in a continuous vertical looping fashion from sub-cutaneous to deep layer and from one end to another, incorporating the lesion within the suture. The suturing is advanced at regular and equidistant intervals to involve the bulk of lesion resulting in compression of the vascular spaces and causing obstruction of the afferent and efferent vessels. This reduces the risk of bleeding, swelling and size of lesion. The blood supply gets interrupted due to obstruction of afferent vessels. In large lesions, this suturing should be done parallel to each other covering the whole lesion from superior to inferior and medial to lateral, which would occlude the regional vascular channels, interrupting and obstructing the blood circulation in the tumour. These sutures must be tightened cautiously, slowly and progressively to achieve gradual and complete strangulation of vascular channels until complete closure of their lumen is assured. This procedure decompresses the lesion completely and reduces the risk of post-operative haemorrhage. The excess skin fap is excised, drains are secured followed by primary closure. The fnal scar is fairly acceptable, as all incisions are originally placed within the skin tension lines.

#### **31.7.5 Approaches and Excision/Debulking**

Superfcial Type-I (Fig. 31.7) lesions mostly derive from the reticular dermis and is treated with direct excision and closure or local-fap reconstruction. Care is taken to place incisions along the skin tension lines of the face and neck to avoid unaesthetic results. It is challenging to select these lines in young individuals and every attempt is made to lay these incisions on prominent skin creases like nasolabial, mentolabial, pre-auricular and lower skin crease of neck.

Type-II (Fig. 31.8) lesions are approached by raising skin faps using the following incisions, commonly—preauricular with either neck skin crease extension or temporal extension, neck crease incision alone, nasolabial skin crease incision, mid-face Weber-fergusson incision and coronal approach. Every attempt is made to maintain a sub-SMAS

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 31.25** Venous malformation right face, lower lip ((**a**) pre-operative, (**b**) post-operative, (**c**) lesion exposure and (**d**) corset suturing of lesion). (Fig. 31.25 a,b,d - copyright authors own publication IJOMS 2018)

plane but vascular anomalies being composite in nature can demand modifcations. There is always a risk of thinning the skin fap excessively and care should be taken to avoid button-holing and avoiding avascular necrosis. The lesion is excised completely or debulked depending on the size. Corseting is used for large low-fow malformations as described above.

Tongue lesions are mostly excised in toto or debulked in a V shaped fashion to achieve primary closure.

Type-III (Fig. 31.9) lesions are approached the same way as Type-II. Being deeper in nature, the gland is sacrifced with some risk of permanent facial nerve damage. Use of 'corseting' in these cases has shown good results with complete recovery of facial nerve weakness over a period of 1 year.

Type-IV (Fig. 31.10) lesions like other types are rarely seen on their own and are usually in combination with Type I, II or V. These lesions are treated with curettage or segmen-

tal resection of bone followed by reconstruction (Fig. 31.13). There are reports of extra-corporeal curettage of segmentally resected lesions and re-fxation to maintain bone continuity.

Type-V (Fig. 31.11) lesions commonly require access to osteotomies like mandibulotomy, segmental or complete Lefort-I, rhinotomy or zygomatic swing osteotomies to gain adequate access. The lesions are uncapsulated and rarely excised completely but improve the quality of life and reduce risk of mortality due to airway obstruction and haemorrhage. In the authors' experience, use of corseting has proven to be benefcial in these cases.

Excess skin fap is always excised to give a near normal appearance. Use of an adequate number of drains and meticulous haemostatic closure is imperative to achieve acceptable and aesthetic results.

Most large lesions require further excision and debulking procedures as the age advances until growth is achieved. Large low-fow lesions have potential to be excised completely secondarily, following prior corset suturing.

Algorithm 31.2 summarises the management of vascular malformations.

#### **31.8 Complications**

Vascular lesions can have complications ranging from none (like in haemangiomas) to bleeding, ulcerations and infection. Superfcial lesions and ulcerations beneft with the use of pulsed-dye laser. Bleeding can usually be managed with compression dressings.

Large venous and lymphatic malformations can cause local swelling, pressure effects on trachea and oesophagus, pain and infection, demanding immediate treatment like embolisation or surgical debulking along with control of airway and infection.

The two common complications of LMs are bleeding within the lesion and infection. Bleeding can be seen spontaneously or as a result of trauma. This further causes immediate and painful enlargement of the lesion with associated ecchymosis. Analgesia and observation usually suffce for symptomatic management. Prophylactic antibiotics can be given in the case of profuse bleeding. Long-term intravenous broad spectrum antibiotics may be necessary covering pathogens of head and neck, especially in high-risk patients. Haemorrhage and infection can sometimes transform a macro-cystic lesion into a micro-cystic type with associated scarring. LMs are known to increase in size in the presence of a viral or bacterial infection. This is usually selflimiting and thought to be due to changes in the lymphatic fow. Bacterial superinfections can be fatal causing ascending cellulitis and septicaemia. Any infection in cervicofacial LMs can cause obstruction of the upper airway and oesophagus causing dyspnea and dysphagia.

Incompletely treated AVMs tend to recur and continue to grow. They should not be underestimated.

#### **31.9 Recent Advances**

Micro-cystic lymphatic malformations have always been challenging cases to be treat, especially involving extra- and intracranial areas of head and neck. Currently available treatments have limited effectiveness and high risk of complications. Techniques using lymphography and idiocyanine green have been used to locate the exact location of afferent and efferent lymphatic fow and performing a lymphatic-venous anastomosis has been described in treating these lesions [27].

Vascular-disrupting agents (VDA's) [28] are a group of 'vascular targeting' agents that show selective activity against tumour vascular networks, causing severe obstruction in their blood fow and subsequent necrosis. These have been investigated for a long time but haven't yet actively been used in the treatment of vascular lesions of the head and neck. Micro-tubule-depolymerising agents are the largest group of small molecular weight VDAs, which include lead compound disodium combretastatin A-4 3-O-phosphate (CA-4-P) [28], and are under clinical development for cancer. VDAs can also interfere with angiogenesis and can be potentially used as novel drugs for the treatment of conditions with excessive angiogenesis, in addition to cancer.

3D remodelling and bioprinting of areas affected by vascular anomalies with their feeder vessels are under study, for training and familiarising one with possible complications during procedures like embolisation and surgery.

#### **31.10 Conclusion**

Vascular anomalies are a diverse group of lesions requiring knowledge and skill to identify, accurately diagnose and treat adequately. Most of these lesions present as a complex problem with a combination of different types and other systemic complicating features. This demands a multi-disciplinary team comprising maxillofacial surgeon, vascular surgeon, pediatrician, reconstructive surgeon, anaesthetist and speech and language therapist with extensive training, understanding and experience to tailor an appropriate treatment plan. Selection of sclerosants should be with caution to minimise their side effects. Surgery has an important role in achieving quicker and long-term stable results in most cases.

#### **References**


tions in the head and neck region. Int J Oral Maxillofac Surg. 2018;47(12):1534–40.


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**Part XII**

**Aesthetic Procedures in Oral and Maxillofacial Region**

## **Non-surgical Modalities of Facial Rejuvenation and Aesthetics**

Arun Kumar Panda and Aarti Chowdhary

#### **32.1 Introduction to Ageing Face**

#### **32.1.1 Facial Changes Due to Ageing**

The Face is a mirror of what we are from inside. It is like an opera that reveals a person's inner self, nature, personality and health. The signs and symptoms of age, illness, defciencies and personality traits show on our faces. A lot can be postulated by just observing the different facial expressions of a person. A minuscule defect on the face engraves an exaggerated long-lasting impression on a person's mind and soul.

Ageing is a process which cannot be defed. With the passage of time, every individual goes through a phenomenon of complex transformations which takes away the youthfulness. The various signs of ageing seen on the face include recession of hairline, wrinkles on the forehead, drooping of the upper eyelid, hollowness in the under-eye area, deepening of nasolabial fold, folds on the face, sagginess of skin at the border of mandible, etc. (Fig. 32.1). Today, with the changing cultures and requirements in the profession, every individual wants to look better than what he or she is.

As the saying goes "Beauty has no age", more and more elderly people also want to have their face rejuvenated. So, today we have a range of patients of vast age variations who want to have a more rejuvenated look. The various modalities for rejuvenating the ageing face require fne skill and artwork combined with scientifc knowledge and understanding of the whole face including scalp, forehead, perior-

A. K. Panda (\*)

Department of Oral & Maxillofacial Surgery,

SD Dental College and Hospital, Parbhani, Maharashtra, India

A. Chowdhary Department of Periodontology, SD Dental College and Hospital,

Parbhani, Maharashtra, India

bital area, perioral area, neck, etc., so as to achieve a more youthful appearance.

Time and technology has evolved. For many years the standard had been chemical peels as the non-invasive procedure to facelift as the invasive modality for face rejuvenation. Today, we have a vast range of procedures and technologies to counter ageing phenomenon and provide a rejuvenated appearance. We shall discuss the various non-surgical modalities in this section which physicians are adopting to treat patients with a wide range of Facial Aesthetic concerns.

The ageing of human face is a highly complex, irreversible and progressive biologic phenomenon that occurs with the ticking of time. The main factors leading to facial ageing include gravity, bone remodelling, subcutaneous fat redistribution and loss, hormonal imbalance, chronic sunlight, pollution and smoking. Other environmental factors that allegedly affect facial appearance include mental stress, nutritional defciencies, work habits, drug abuse and disease. This dynamic process is a synergistic effect of various factors and actually takes place at 4 distinct levels (the 4 S levels): Skin, Subcutaneous tissue, SMAS and facial Skeleton.

#### **32.1.2 Ageing of Skin**

The epidermis contains keratinocytes and dead corneocytes. The basal cells at the stratum basal divide to form keratinocytes, produce keratins and drift upwards as they mature. By the time keratinocytes reach the most superfcial layer, they lose their nucleus and cytoplasmic organelles and are known as corneocytes. In a total period of 40–50 days, the keratinocytes come to the surface and corneocytes exfoliate. This time taken for the process of keratinisation, that is maturation of keratinocytes along with shedding of corneocytes, is known as the turnover time.

The natural process of desquamation sheds off the dry, old, hardened skin cells and gives way to the new cells to

**32**

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_32) contains supplementary material, which is available to authorized users.

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 661

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_32

**Fig. 32.1** Various signs of an ageing face include but not limited to forehead wrinkles, droopy eyelids, under-eye hollowness, deep nasolabial folds, jowl formation, loose neck skin and thin lips

©Association of Oral and Maxillofacial Surgeons of India

come to the surface. This process also eliminates damaged and contaminated cells that carry pollutants and microorganisms from the environment.

The specialised fbroblasts in the dermal layer produce two key proteins-collagen and elastin. Collagen constitutes 80% of the dermis and provides strength and frmness to the skin. While elastin, as the name implies, provides elasticity to the skin and enables the skin to bounce back to its original shape after it is stretched, thus preventing wrinkles.

Skin ageing is a dynamic mechanism that transpires due to two basic factors:


Intrinsic ageing is an inevitable natural ageing process which commences as early as mid-20s. It consists of internal physiological factors that cause inherent degenerative process in the body. Dead corneocytes do not desquamate as swiftly as expected and the turnover of new epidermal cells decreases somewhat. In the dermis, the production of collagen and elastin slows down. The cumulative effect which is seen in case of the inherent ageing includes fne wrinkling, parched, thin and transparent skin and depleted elastic nature of the skin.

Extrinsic ageing is because of the aggregated damage caused by environmental factors such as sun's UV radiation, gravity, sleeping posture, pollution, smoking, exposure to chemicals, etc. These exogenous factors along with the innate factors cause premature ageing of our facial skin. The face, which is most commonly exposed part of the human body to the UV radiations of the sun, undergoes ageing prematurely than any other part. Photoageing with recurrent sun exposure causes the skin to lose its capability to renovate and thereby accumulating damage. Recurrent and continual UV exposure disintegrates collagen and impedes the synthesis of new collagen. Alongside, there is a breakdown of elastin. This causes the facial skin to become slack, wrinkled and leathery much earlier than a sun-protected skin.

Gravity constantly works on different parts of our facial skin. As the skin elasticity reduces with age, the effects become evident. It precipitates jowls, nasolabial fold, drooping of eyelids, elongation of ears, etc. (Fig. 32.2).

Sleep lines are wrinkles that are etched on the facial skin of the people who sleep with the face pressed on the cushion or sleep on the sides.

Cigarette smoking over a period of time causes many biochemical alterations in our body. It has deleterious effects on skin and expedites the ageing process. The nicotine causes vasoconstriction thereby impairing the supply of oxygen and

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 32.2** Infuence of ageing on skin. Facial wrinkling, jowls and droopy eyelids clearly demonstrate the ageing process

important nutrients, such as vitamin A to the skin. Many of the over 7000 chemicals released from the burning cigarettes cause increased production of matrix metalloproteinases (MMP) that causes degradation of collagen and causes abnormal creation of elastosis materials. These cause premature facial skin wrinkling.

#### **32.1.3 Ageing of Subcutaneous Tissue**

The subcutaneous fat gives the volume and shape to the face. As explained by Rohrich and Pessa [1], the subcutaneous fat is distributed throughout the face in a multidimensional fashion and is highly compartmentalised. A youthful face is characterised by a smooth transition between these subcutaneous compartments. The superfcial musculoaponeurotic system (SMAS) divides this fat into superfcial and deep layers. As explained anatomically by Rohrich and Pessa [1], the external recess is in between the skin and SMAS while the internal recess lies under the SMAS and is adherent to the periosteum. The superfcial and deep fat recesses are as explained in Fig. 32.3.

Furnas in 1989 frst described the osteocutaneous ligaments within the cheek that anchor the dermis to the underlying fbro-osseous structures [2]. He outlined the zygomatic ligaments (McGregor's patch), the mandibular ligament, the platysma auricular ligament and the anterior platysmacutaneous ligament that anchor the dermis and also support the midface soft tissue. Two theories explain the characteristic soft tissue changes that are distinguished during the mid-face ageing. The gravitational theory advocates that with the attenuation of the osteocutaneous ligaments, there is vertical descent of facial soft tissue which contributes to the deep creases of the ageing face [3]. The diminished strength of the ligaments is because the age-related elastosis and also because of the repeated animation of the muscles of facial expression.

Donofrio explained the volumetric theory in 2000. He suggested that it's the corresponding volume loss or gain in the adjoining areas of the face is what creates the deep creases of age [4]. This theory was later in 2007 reinforced by Lambros who stated that the ageing process was due to the relative defation of certain fat pads, especially the deep fat pads [5].

#### **32.1.4 Ageing of SMAS**

The superfcial musculoaponeurotic system is a multidimensional scaffold of organised fbrous tissue that connects the facial muscles with the dermis [6]. This fbromuscular layer also segregates the superfcial and deep facial fat pads. Anatomically, the SMAS lies in the midface, inferior to the zygomatic arch and superior to the muscular belly of the platysma. It blends with the superfcial temporal fascia and frontalis muscle superiorly, and with the platysma muscle inferiorly. Since it connects the facial muscles to the dermis, its purpose is to transmit, distribute and amplify the activity of all facial muscles [7].

As we age, and with the continuous use of the muscles of facial expression, the SMAS weakens and the strength diminishes. So, the ability to hold up the muscles, fat and the skin gets impaired. Combined with the effect of gravitational forces, the weakening causes the structures of the face to slump. The youthful appearance of the face changes as jowls are formed, the nasolabial fold deepens and the mandibular line angle becomes ill defned.

#### **32.1.5 Ageing of Facial Skeleton**

The bony skeleton serves as a framework for the soft tissues of the face including the skin, muscles and subcutaneous fat. The facial skeleton keeps changing anatomically throughout life with only degenerative and catabolic changes occurring after adolescence.

With ageing, the facial skeleton keeps resorbing in a very predictable manner and that contributes to the appearance of an aged face. Areas with strong tendency to resorb include the periorbital area, the midface, the perinasal area and the mandible (Fig. 32.4).

**Fig. 32.3** (a, b) (**A**) Infraorbital fat, (**B**) Medial cheek fat, (**C**) Nasolabial fat, (**D**) Medial cheek fat, (**E**) Lateral cheek fat, (**F**) Superior jowl fat, (**G**) Inferior jowl fat, (**H**) Medial sub-orbicularis fat, (**I**) Lateral sub-orbicularis fat, (**J**) Deep medial cheek fat, (**K**) Buccal fat

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 32.4** Various areas of facial skeleton as marked are predominantly destined to resorb contributing to the appearance of aged face

The orbital aperture enlarges with age in all dimensions. The superomedial and inferolateral aspects tend to recede more which imparts the stigmata of periorbital ageing such as increased prominence of the medial fat pad, elevation of the medial brow and lengthening of the lid cheek junction [8].

The midface skeleton is formed by the maxilla medially and the zygoma laterally. With age, the maxilla recedes and the maxillary angle decreases by about 10° between the age of 30 and 60 years [9]. The piriform aperture enlarges with age, as the edges of the nasal bones recede [10]. The anterior nasal spine also retreats which reduces the skeletal support and thereby contributing to retraction of the columella, with a downward rotation of nasal tip and apparent lengthening of the nose [11]. In regards to the mandible, it is well established that the mandibular angle increases, the ramus height and mandibular body height and length decreases with age [12]. The above-mentioned skeletal resorption patterns contribute signifcantly to the appearance of an ageing face.

In the recent years, the demand for facial rejuvenation has increased exponentially. Individuals from every socioeconomic strata and from all age groups today desire a younger and rejuvenated look. Evolution of numerous surgical and non-surgical procedures has led to an increase in patient demands and expectations. Every aesthetic physician should understand the facial anatomy and the facial ageing process well so as to perform the procedures that would best suit the requirement of the individual to deliver the best of the results. The various non-surgical modalities of facial rejuvenation include the use of Botulinum toxin, dermal fllers, thread lifts, platelet concentrates and radiofrequency waves. Botulinum toxin and fllers are elaborated in the subsequent chapter. The following is a detailed description of the role of thread lifts, platelet concentrates and radiofrequency waves in achieving facial rejuvenation.

#### **32.2 Non-surgical Facelift with Threads**

Age-related changes on the face include remodelling in the facial skeleton and reorganisation of musculature, connective tissues, fat and skin. The dynamic process of ageing is unstoppable and it induces an ever-progressing slackness in the soft tissues that leads to a ptotic brow, jowl formation, ill-defned mandibular margin and deep nasolabial folds.

Gravity is an important factor that causes drooping of the upper, mid- and lower-facial soft tissue, which adds to the effect of an aged appearance. The hollowness of the midfacial and infra-orbital area is because of the downward shift of the malar fat pad. To manage this ptotic situation, surgical facelift procedures have been the most effective treatment as they not only excise the redundant tissues but also haul the soft tissue in the opposite vector of ageing process. The other non-invasive procedures cannot be as effective as the facelift procedure. But because of the signifcant downtime, cost and risks involved, facelift is not accepted by patients very readily. To have a way in between the surgical and non-invasive modalities, thread lift has become a popular procedure to manage drooping tissue of the face because of ageing.

#### **32.2.1 Introduction to Thread Lift**

Thread lifting modality is a minimally invasive cosmetic procedure that utilises a biocompatible implant placed into the deeper layers of face to predictably shift and realign tissues in a predetermined direction or vector. When compared to a surgical facelift procedure, this elevates the drooping tissues with least amount of risks and complications, immediate results and rapid recovery.

Historically, Ruff in Durham, North Carolina, in 1992 and Sulamanidze et al. in Moscow, Russia, in 1996 independently developed barbed sutures for correcting facial ptosis. FDA in 2004 approved Ruff's clear, barbed, unidirectional, polypropylene sutures for treating ptotic skin of face and neck [13].

#### **32.2.2 Classifcation**

	- Redefnition of the facial contours—Barbed threads • Induction of collagen production—Mono PDO
		- threads

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 32.5** Various types of polydioxanone threads are mono threads for facial rejuvenation and cogs threads for redefning facial contours

	- Permanent/Non-resorbable threads—Polypropylene threads like Aptos threads, Silhouette lift threads, etc.
	- Resorbable threads—Polydioxanone threads like Alfa aqualift, and Poly-L Lactic acid threads like silhouette soft threads, etc.
	- Anchored: Wherein the thread is anchored to a proximal fxed place like the deep temporal facia or mastoid facia.
	- Free foating: They are not fxed and cause the pull because of the thread design.
	- Barbed
		- Non-barbed

The Barbed threads are of 3 types:


The Non-barbed threads can be:


#### **32.2.3 Mechanism of Action**

From a clinical point of view, the barbed sutures simply work by grasping and mechanically pulling the ptotic skin. These barbs get entangled in the subcutaneous tissues and as the thread is pulled backwards, the tissues get squeezed along the barbs and stay there as the thread outside is cut off.

From a histologic aspect, a basic mechanism of mechanical transduction happens when the polydioxanone threads are placed in the tissues. A torrent of intracellular signals in the surrounding cells through which the polydioxanone threads pass is triggered by the mechanical stresses instigated by the threads thus infuencing the metabolic responses and encouraging cellular growth and survival and modulating tissue morphology and architecture [14].

There are 2 major types of collagen proteins that are found in our skin. The type 1 collagen or the fbrous collagen makes up about 70% of the total collagen while the type 2 collagen or the reticular collagen makes up to about 5–20%. Both of them provide structural support to the skin. Today, most of the aesthetic procedures are aimed at a phenomenon of biostimulation. The main intention is to improve on the plasticity, resilience, fexibility, frmness and turgor of the skin tissues that are normally lost with ageing due to the loss of proteins like collagen and elastin. This is achieved by penetrating the dermis with substances that would encourage the production of these proteins [15]. The biostimulation caused with PDO threads is due to neocollagenesis, i.e. the production of type 1 collagen which is essentially fbrotic in nature. The PDOs resorb in 6 months and till that time it keeps inducing collagen. The fbrotic collagen exhibits a retracted effect improving the skin appearance. Concurrently, the compaction and stiffening of the collagen fbres also determine the functional damage [16].

#### **32.2.4 Indications**

There are 2 major indications for the threads treatment:


Skin rejuvenation can be done with the use of plain polydioxanone threads. It also increases the volume in certain areas where there is minimal volume loss.

The barbed threads are indicated in areas where there is ptosis of the tissues. The barbs work as cogs and by engaging the tissues along its path, it mechanically pulls the tissues upwards thereby reducing the ptosis.

The plain polydioxanone threads can be used for facial rejuvenation and are mostly utilised for the following indications (Fig. 32.6):


The barbed threads can be used to lift the ptotic skin and hence be utilised in the following areas (Fig. 32.8):


#### **32.2.5 Treatment Protocol** [4]

Choosing the ideal procedure for rejuvenation depends on the grade of skin ageing.

(A) Mild skin ageing

	- for a "natural look" lifting—apply PDO cogs along with plain PDO threads.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 32.7** (a, b, c) Mono polydioxanone threads can be used to create the lip borders and also to create a fuller looking lip

	- Rejuvenation—Apply short PDO cogs along with plain PDO threads (Fig. 32.10).
	- Lifting—Not recommended.

#### **32.2.6 Procedure**

The Polydioxanone thread used in facial rejuvenation are basically of 2 types: Mono PDO thread and Cogs PDO thread

(A) The Mono PDO thread—These are 5-0 or 6-0 suture materials which are essentially monoflament and **Fig. 32.8** Various indications of barbed PDO threads for redefning facial contours and lift the ptotic tissues

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 32.9** Mono PDO threads for facial rejuvenation

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 32.10** Cogs thread for lifting nasolabial folds. Note the lifted up right nasolabial fold only as the thread has been applied only on that side. Left side is still untreated

non-barbed. It can also be braided to a spring to provide more tensile strength [17]. The thin suture material forms a V-shape when inserted to a needle of 26–30 g, with one half of the thread inside the calibre of the needle and the other half on the outside. Once the needle with the suture material is inserted into the dermal layer, the thread gets buried into the tissues and at the removal of the needle, the thread stays back intact.

These types of threads are placed in the dermal layer where they cause collagen formation.

EMLA cream must be applied 45 min prior to the procedure. The full face was cleansed with povidone iodine solution. Once ready, the mono PDO threads are placed in the dermal layer making up meshes in the areas of indication. One must keep observing for any threads that stay outside the skin. It must be removed immediately by grasping it with a needle holder so that it doesn't cause any infection or granuloma.


Post-operatively, ice packs are applied to minimise edema and bruising. Oral antibiotics are prescribed for 5 days after the procedure.

Anti-infammatory tablets should be avoided as the more the infammation at the site, the better would be the results. Patients generally do not require anti-infammatory drugs post-surgery. Within the frst 3 weeks after the procedure, the patients are advised against any strenuous movements of the muscles of midface such as yawning, wide smiling and laughing.

#### **32.2.7 Complications and Management**

The various complications that could occur with the PDO barbed threads include:


always a good practice to let the patient seat vertically straight while inserting the barb threads and making the patient participate while retracting the tissues by visualising with a mirror to avoid any potential problems of asymmetry later on.


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 32.11** (**a**, **b**) Placement of cannula with cogs threads along the vectors for nasolabial folds and after removal of cannula the cogs threads in place. (**c**, **d**) Pulling the cogs threads to lift the ptotic nasolabial fold tissues and fnal twisting and snipping the threads just below the skin level

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 32.11** (continued)

#### **32.2.8 Conclusion**

The PDO thread lift is a non-invasive procedure that actually gives a "lifted effect" of the ptotic skin. It has been widely accepted as a standard procedure for patients who do not want to opt for a more aggressive surgical facelift. Patient selection is of prime importance. Only patients with mild to slightly moderate levels of ptosis should be selected for polydioxanone cogs thread lift. The patient should be given a realistic expectation of the lift of no more than 1 cm. Patients who are too chubby or who are too skinny should not be considered for thread lift. Overall, every aesthetic practitioner should have knowledge of thread lift as it is a simple and versatile anti-ageing procedure.

#### **32.3 Biostimulatory Lift with Platelet-Rich Plasma**

Today, Platelet-rich plasma (PRP) has been incorporated in many medical specialities including orthopaedics, general surgery, plastic surgery, dental surgery and dermatology because of its healing capabilities. Its usage in aesthetics and trichology has touched newer horizons as we have come to know about the healing cytokines present in the platelets which can be used for antiageing therapies and therapies for regenerative aesthetics.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 32.12** (**a**, **b**) Damage to frontal branch of the facial nerve during placement of cogs threads

#### **32.3.1 Platelets and Platelet Concentrates**

Platelets, also called thrombocytes, are enucleated fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow, which are released into the circulation. They have a fundamental role in haemostasis and wound healing.

The platelets contain various secretory granules, namely the alpha granules, dense granules and lysosomes. The alpha granules are the most abundant ones and contain the coagulation factors, growth factors, also called cytokines, adhesion molecules, and a variety of other angiogenic factors which effciently encourage the proliferation and activation of cells required for wound healing including fbroblasts, mesenchymal stem cells (MSCs) and facilitates angiogenesis [18].

The growth factors along with their function are listed below [19]:


motility, adhesion and apoptosis as well as causes wound healing and angiogenesis.


These growth factors or the "cytokines" are proteins, each of about 25,000 Daltons molecular weight. In response to the thrombocyte aggregation, as occurs in injury or surgery, the cell membrane activates the alpha granules which in turn unleash these growth factors via active extrusion through the cell membrane. The active secretion begins within 10 min during which 70% of stored growth factors are released and more than 95% of the presynthesised growth factors are secreted within 1 hour. Platelets then synthesise additional amount of growth factors for about 8 days till they die [20].

Platelet concentrate means plentiful amounts of platelets that are concentrated into a small volume of plasma. There are various types of platelet concentrates which can be formulated, all differing in the way they are made [21]. A general classifcation takes 2 key parameters into consideration: the presence of a cell content (mostly leukocytes) and the fbrin architecture.

There are 4 major families:

#### 1. P-PRP

Pure Platelet-rich plasma is a preparation without Leukocytes. It has low-density fbrin network after activation. It is used as liquid solutions or an activated gel form and can be injected. P-PRP is commonly used in sports medicine & aesthetic medicine.

2. L-PRP

Leukocyte and PRP is a preparation with leukocytes in it. Even this has low-density fbrin network after activation. It is used as liquid solutions or an activated gel form and can be injected. L-PRP is used in aesthetic medicine, sports medicine, orthopaedics, trichology, etc.

#### 3. P-PRF

Pure Platelet-rich fbrin is a preparation without leukocytes. It has a high-density fbrin network and exists as a strongly activated gel form. It cannot be injected, but can be handled like a real solid material. It has been very commonly used in dentistry & maxillofacial surgery today.

#### 4. L-PRF

Leukocyte and PRF is a preparation with leukocytes. It has a high density of fbrin network and exists as a strongly activated gel form. It cannot be injected and can be handled as a real solid material. It is today used in implant dentistry, periodontal surgeries, oral surgeries, treatment of skin wound ulcers, etc.

#### **32.3.2 Mechanism of Action of PRP**

PRP can be described as a biologic product derived from autologous blood with the plasma fraction containing platelets at a concentration of more than 3–5 times above baseline.

The scientifc evidence suggests that wound healing enhancement is seen using concentrates of 1,000,000 platelets/μl. Any concentration lower than this cannot be depended on to enhance wound healing, and concentrations far more than this has not been scientifcally proved to help and enhance healing [22].

So, PRP by virtue of its increased concentration of platelets and thereby an infated amount of growth factors or cytokines have been theorised to encourage tissue repair and regeneration by neocollagenesis, neoangiogenesis and much more. It has been embraced as a frontline treatment modality for the management of facial ageing, androgenetic alopecia, acne scarring, etc.

#### **32.3.3 Indications of PRP Therapy in Aesthetic Medicine**


#### **32.3.4 Preparation of PRP**

PRP is derived from autologous blood by using a centrifuge and can be performed under local anaesthesia under aseptic conditions. An anticoagulant, like citrate dextrose solution formula A (ACD-A) or sodium citrate 3.8%, is used to inhibit platelet aggregation.

#### **Manual Double Spin Method** (Figs. 32.13, 32.14, 32.15, and 32.16)

Whole blood is collected by venipuncture from antecubital vein in 15 ml polystyrene tubes under sterile conditions containing 3.8% sodium citrate as an anticoagulant. In each tube, 1 ml of sodium citrate is mixed with 12 ml of whole blood. Eight such tubes are taken to make up a volume of 104 ml. The tubes are slowly turned upside down twice to homogeneously mix the whole blood with the anticoagulant. All the 8 tubes are placed in the centrifuge (Remi 8c) and are centrifuged at 1500 rpm for 10 min. This is called the 'soft spin' which separates the whole blood into 3 layers. The erythrocytes settle at the bottom of the tube because of the highest specifc gravity or density of about 1.090. Just above the erythrocytes, a hazy layer is seen which contains the leucocytes with a specifc gravity of 1.060 and platelets with a specifc gravity around 1.040. At the top, we fnd the clear plasma with the lowest concentration of platelets with a specifc gravity of around 1.020.

The buffy coat is separated along with some amount of plasma and placed in a separate tube. At this time, if the buffy coat is separated along with the slightest superfcial erythrocyte layer, it is referred to as L-PRP (leukocyte-PRP) and if it

is taken above the layer of erythrocytes, it is referred to as P-PRP (pure-PRP) depending on the kind of PRP preparation, i.e. with or without leukocytes. About 10 ml of these are taken in 2 tubes and placed in the centrifuge for a second spin called the 'hard spin' at 2500 rpm for 15 min. At the end of the spin, a platelet plug is found at the bottom of the tube. The top 3 quarter of the platelet poor plasma was discarded and the lowest quarter with the platelet plug was mixed and used as the PRP. This gives us a viable platelet count of 5 times the baseline. This was activated by mixing with calcium gluconate at a ratio of 9:1 in an insulin syringe and injected immediately.

### **Automated Devices** (Fig. 32.17)

Numerous commercial devices of varying standards are now available for the preparation of PRP. Although time saving, these adapted kits can be quite expensive as compared to the manual process.

In general, a PRP tube typically contains sodium citrate as an anticoagulant along with a separating gel. This gel has a density of about 1.070, which is in between the erythrocytes and platelets.

20 ml of Whole blood is collected by venipuncture and added into two of these PRP tubes. The blood is homogeneously mixed with the anticoagulant by gently turning the tube upside down twice. The tubes are then placed in the centrifuge and spun at 3700 rpm for 9 min. The erythrocytes because of the higher density than the separating gel settle down below the gel, while the plasma along with leucocytes and platelets segregate above the gel. The superfcial platelet poor plasma is discarded leaving behind 2–3 ml of plasma above the gel. The tubes can be turned upside down to mix the platelets as they get entangled in the gel. This would give a uniform concentration of platelets throughout. It is now mixed with calcium gluconate as an activator and injected immediately.

©Association of Oral and Maxillofacial Surgeons of India

#### **32.3.5 PRP Injections for Facial Rejuvenation, Biostimulatory Lift and Acne Scar**

Studies have shown that PRP by inducing neocollagenesis through activation of fbroblasts and by removing photodamaged extracellular matrix (ECM) components amplifes dermal elasticity via following molecular mechanisms [23, 24]:


PRP can be injected using an insulin syringe that has 31 g needle. Local anaesthetic in the form of nerve blocks should be given prior to the session. The facial skin should be cleansed with povidone iodine solution. Multiple intradermal injections of PRP after activating it are given all over the face including the infraorbital area. Three sessions each at a gap of 1 month of PRP therapy along with micro-needling (collagen induction therapy) with derma pen with a needle depth of 0.7–1 mm has been shown to give very good results for rejuvenating the aged skin and acne scars. Histologically, the treated skin showed improved length of dermo-epidermal junction, increased quantity of collagen and fbroblasts.

Post-operatively, patients are advised to apply ice on the face. Sun exposure should be avoided. Patient should be advised not to take anti-infammatory tablets as the more the infammation, the better the results are going to be. Most of the times, patients experience very mild post-operative discomfort.

PRP therapy can also be combined with CO2 fractional resurfacing to achieve excellent results in treating acne scars.

PRP has also shown excellent results in infraorbital rejuvenation where the skin is very thin and shows initial signs of ageing [25].

**Fig. 32.15** (**a**, **b**, **c**) Platelet plug formed after the second spin during the preparation of L-PRP

### **32.3.6 Contraindications to PRP Therapy** [26]

Absolute contraindications:


Relative contraindications:


### **32.3.7 Conclusion**

The use of cytokines derived from platelet-rich plasma (PRP) is an effective modality to promote tissue regeneration and hence can be used in regenerative medicine including facial aesthetics and trichology.

PRP therapy is an inexpensive procedure as it does not require complex and voluminous equipment or extensive training for its execution. Furthermore, since the product is primarily autologous in origin, the patient's apprehension regarding the immunogenic reactions or disease transmission is abolished. Over three decades of its application to various felds and the multitude of studies with enormous positive results, PRP therapy today has become a gold standard for facial rejuvenation and hair loss therapy. The release of bioactive cytokines that help in neocollagenesis which takes care of the ageing process of wrinkle formation has made it a versatile tool for many anti-ageing therapies on the face.

**Fig. 32.16** (**a**, **b**, **c**) Platelet-rich plasma needs to be activated for release of cytokines from the alpha granules

#### **32.4 Face Tightening with HIFU (High Intensity Focussed Ultrasound)**

Facial wrinkles, reduced elasticity of the facial skin and sagging parts of the face are the most common concerns today an aesthetic surgeon encounters from the patients. In the present social scenario, facial skin laxity is considered highly disgraceful and has a great impact on a person's psychology and quality of life [27]. The natural process of ageing which is inevitable and the other external factors like sun's UV radiations, stress and worry, smoking, unhealthy diet, etc. are the major factors which cause the wrinkles and sagginess. We are aware that the loss of the important proteins viz collagen and elastin, which gives the strength, resilience and elasticity to the skin is the reason behind the loose skin and wrinkles.

Various treatment modalities have been utilised to manage these concerns of the face. Surgical excision of the redundant skin via facelift surgery defnitely gives the best results. But with the increasing concerns over the complications and the downtime, the focus of therapeutic modalities is shifting towards non-surgical aspects.

Non-surgical treatment modalities like microdermabrasion, chemical peels, fractional lasers, etc. have been advocated in the past. In recent times, newer modalities like the HIFU and RF have come into limelight due to their noninvasiveness and low or no downtime for the treatment of sagging skin.

#### **32.4.1 Introduction to HIFU**

Ultrasound was introduced for its diagnostic ability. The capability of the focussed ultrasound energy to cause tissue regression and ablation has been well utilised today as a noninvasive modality to treat solid tumours and also being used to treat both primary and metastatic tumours as these can precisely locate the mass for ablation [28].

More recently this intense focussed ultrasound has also been utilised in many painful conditions including neuropathic pain and musculoskeletal degeneration [29].

**Fig. 32.17** (**a**, **b**, **c**) Preparation of Platelet-rich plasma with the help of PRP tubes containing anticoagulants and the separating gel

HIFU or high intensity focussed ultrasound was introduced into the feld of facial aesthetics very recently to manage the facial wrinkles and periorbital rejuvenation.

FDA in 2009 approved the use of HIFU in brow lifting as the frst dermatologic and aesthetic indication following the report by White et al. [30] in 2008. It was later in 2014 cleared as an indication to improve lines and wrinkles of the upper chest and neckline (décolletage). Currently, its use for facial rejuvenation, skin lifting and tightening and body contouring is considered 'off-label'.

#### **32.4.2 Mechanism of Action**

High intensity focussed ultrasound or HIFU embodies a piezoelectric transducer which produces focussed ultrasound beams. This transducer releases ultrasound waves over a length of around 2.5 cm which are focussed at 1.5, 3 or 4.5 mm depth. The 1.5 mm focusses the superfcial or papillary dermis, while the 3 mm focusses the deep or reticular dermis and the 4.5 mm focusses the SMAS layer. Like a magnifying glass, the transducer focusses the ultrasound to the desired depth and at the focal spot, there is a swift rise in temperature to 60–80°C within a very short period (typically 1–20 s). This causes an immediate contraction of native collagen which is subsequently followed by cell injury and tissue shattering due to both coagulation necrosis and protein denaturation. These events occur at the deeper focussed zones, while the superfcial tissues are left safe and unaffected [31] (Fig. 32.18).

The focussed ultrasound energy is absorbed by the tissues and this causes the molecules to vibrate rapidly. The friction due to molecular oscillations results in heat generation and a rapid rise of temperature at the focal zone. This thermomechanical process causes tissue injury at the site of focus. Supplemental to this, the ultrasound waves that propagate through the tissues cause continuous compressions and rarefactions that result in powerful shear forces. This microscopic but mighty shearing motion results in frictional heating [32]. Once tissue destruction is done, the infammatory phase (in frst 48 h) sets in wherein the damaged cells are removed and the WBCs, growth factors and enzymes create swelling, heat, pain and redness.

**Fig. 32.18** Mechanism of high-intensity focussed ultrasound. Thermal coagulation zones are created due to the extreme heat produced by the ultrasound focussed to a particular depth

©Association of Oral and Maxillofacial Surgeons of India

In the next proliferative phase (up to 6 weeks), there is tissue contracture due to the myofbroblasts which are built. New tissues made up of collagen and extracellular matrix are formed.

The last maturation phase (from 3 weeks to 6 months) shows collagen is remodelling from type III to type I. The collagen which was laid down during the proliferative phase is now aligned along the tension lines and also there is cross-linking of the collagen. A histological evaluation post HIFU treatment exhibited signifcantly regenerated and proliferated quantity of dermal collagen and elastic fbres [33]. This causes skin tightening over a period of time. The results keep improving and the best fnal results are seen by 6 months.

#### **32.4.3 Armamentarium**

The HIFU machine basically consists of 2 parts: the body and the transducer (Fig. 32.19).

The screen in the body keeps monitoring the number of shots, depth of shots, length of release of ultrasound waves and the energy of the ultrasound in real time. The transducer releases the focussed ultrasound waves. The following are the 3 transducers usually used on the face:

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 32.19** High-intensity focussed ultrasound device


### **32.4.4 Indications and Contraindications in Facial Aesthetics**

The numerous indications of HIFU are given below.


The contraindications are the following;


#### **32.4.5 Procedure for Face Tightening**

#### **32.4.5.1 Facial Rejuvenation - HIFU** (Video 32.1)

The sequence for HIFU application includes the following:


### **32.4.6 Adverse Efects**

Severe adverse effects of HIFU are very rare and hence considered a very safe procedure to perform on an outpatient basis. The adverse effects that have been described may be:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 32.20** (a, b) Lifting of nasolabial fold with HIFU


#### **32.4.7 Conclusion**

HIFU can be considered as a very effective, non-invasive and safe procedure for tightening the facial skin. The advantages over a surgical facelift are hard to deny. There are no incisions, no scarring and no downtime. Of course, it is much less expensive than a surgical facelift. If patients are chosen carefully, like patients with mild to moderate skin laxity, facial wrinkles, lower eyelid laxity, etc., HIFU can be an excellent option for facial skin tightening.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 32.21** Complication during HIFU—erythema and skin burn

**Fig. 32.22** Mechanism of action of non-ablative radiofrequency. Collagen remodelling takes place because of the heat generated due to the tissue resistance to radiofrequency energy

#### **32.5 Skin Tightening with Radiofrequency**

Non-ablative radiofrequency or RF is another non-surgical and non-invasive modality of skin tightening. The selective and controlled rise in tissue temperature is because of a highfrequency alternating current (0.3–10 MHz). The amount of energy applied and the tissue resistance determine the amount of temperature and the depth of heating [34].

Since electrical current produces the RF energy, the tissue damage like a laser is minimised and neither is the epidermal melanin compromised to cause hyperpigmentation.

RF therapy was frst FDA approved as a non-invasive treatment modality in periorbital rhytids in 2002. Subsequently in 2004 it was cleared for full face. Since then, it has become a very popular non-invasive treatment modality for the facial skin tightening.

#### **32.5.1 Principle of Action**

High frequency (0.3–10 MHz) alternating current is utilised in a RF therapy. Intrinsic tissue resistance (impedance) to the passage of electrons converts the electric current to thermal energy causing heat generation. Ohm's Law relationships state that:

Power a ( ) *P I* = ´ *R E* nd Energy( ) = ´ *P T* <sup>2</sup>

Hence, Energy (*E*) = *I*<sup>2</sup> × *R* × *T* (where *I* = current, *R* = tissue impedance and *T* = time of application). The level of energy of the alternating current and tissue resistance determines the amount of rise in temperature and the depth of heating. High tissue resistance as demonstrated by subcutaneous fat generate more heat [35]. The thermal damage thus caused stimulates the alterations in collagen confguration and produces neocollagenesis in deep layers of skin and subcutaneous tissue (Fig. 32.22).

Signifcant results can be observed 2 months postapplication of radiofrequency energy. Histological pictures after each session demonstrated expansion of the papillary dermis due to oedema and vascular congestion, followed by accumulation of intercellular substance. Post 2 months treatment histological pictures showed escalated amount of collagen, elastic fbres and mucopolysaccharides [36].

#### **32.5.2 Armamentarium**

There are 2 major components of the RF machine: the RF generator and the handheld tips (Fig. 32.23). The membrane electrode functions by dispersing energy uniformly across the skin surface by a mechanism termed as capacitive coupling that creates a zone of raised temperature at depths of 3–6 mm [37]. The energy transmitted to the skin is by utilising the capacitive method (bipolar, tripolar or multipolar electrode). Montesi et al. (2007) described the main difference between the inductive and the capacitive method. It depends on the confguration of the electrodes that are applied to the skin that infuences the energy transmission in the tissues.

The inductive method (monopolar electrode) uses an active and a passive electrode, in which the passive electrode acts as a grounding electrode. The active electrode transmits power to the tissue via a single point of contact. This enhances the penetration of the generated current.

In the capacitive method (bipolar, tripolar or multipolar electrode), energy alternates between 2 electrodes situated at a short distance from one another. In the tripolar and multipolar devices, bipolar energy switches between dif-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 32.23** Non-ablative radiofrequency device

ferent poles at any given point of time. The energy is concentrated at the site of treatment and the achieved depth is half of the distance between the two electrodes [38].

Parameters utilised by the device includes frequency ranging from 1 to 6 MHz and the power ranging from 40 to 240 W. All the parameters can be modifed during the treatment. Throughout the procedure, the temperature of epidermis is maintained at 40 °C, whereas that of dermis rises to about 50–75 °C. This heating up of the dermis causes new collagen and elastin production.

#### **32.5.3 Indications**

The various indications of RF include the following:

	- 5. Nasolabial folds (Fig. 32.24)
	- 6. Perioral fne lines
	- 7. Undefned jaw line

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 32.24** (**a**, **b**) Nonablative radiofrequency for tightening nasolabial folds

#### **32.5.4 Advantages**

The biggest advantage of RF is unlike lasers, the energy does not disturb the epidermal melanocytes and thus can be used for all skin types, i.e. type 1–6. The procedure can be performed frequently as per requirement without any adverse effect and different depths of tissue can be treated, allowing for ultimate collagen contraction and production of new collagen.

#### **32.5.5 Procedure of RF for Face**

Application of RF is done systematically and the various steps involved are mentioned below.


#### **Box 32.1 Side Efects of RF Treatment**


#### **32.6 Conclusion**

Non-ablative radiofrequency is an effective and non-invasive modality for tightening and rejuvenating wrinkled, photoaged facial skin and contour facial skin laxity. It works on the principle of stimulation repair process by producing new collagen and elastin and by reversing the clinical and the histopathological signs of ageing. The procedure has an added advantage of being relatively risk-free with little or no downtime.

Disclosure Authors have no fnancial conficts to disclose.

#### **32.7 Case Scenarios**

#### **32.7.1 Patient 1** (Fig. 32.25a–d)

A 48-year female approached us with complaints of sagging skin. She wasn't happy with her deepening nasolabial folds, loose skin in her neck and the fne wrinkling on her face.

Treatment options included surgical facelift, thread lift therapy and non-invasive therapies like HIFU and RF. The patient consented to undergo non-invasive treatment which included a session of High intensity focussed ultrasound (HIFU).

After cleansing the face, proper markings were made. The treatment was performed with sequential transducers of 4.5, 3 and 1.5 mm with number of shot as recommended, area wise. The patient was evaluated post-operatively and patient's satisfaction was recorded. Post-operative instructions were given before discharging. Patient was recalled for revaluation after 1 month.

#### **32.7.2 Patient 2** (Fig. 32.26a–g)

A 52-year male approached us with complaints of loose skin on the face. His main concern was the deepening nasolabial folds and the fne wrinkling on the face. The treatment options included surgical facelift and thread lift therapy. The patient consented to get a thread lift procedure done. It was decided to use 3 COG threads along with 20 mono PDO threads on either side.

After cleansing the face with povidone iodine, vectors were marked to lift the nasolabial folds. Lignocaine with adrenalin was used as local anaesthetic agent. The thread lift procedure with COGS thread was performed with placement of the COGS in the subcutaneous layer for the proper lift and

**d**

**Fig. 32.26** Case Scenario 2. (**a**) Pre-op photograph. (**b**) Marking of vectors. (**c**) 3 cogs in place at subcutaneous layer. (**d**) The traction on threads lifts the nasolabials. (**e**) Placement of mono PDOS. (**f**, **g**) Post-op photograph (also see Fig. 32.10)

**Fig. 32.26** (continued)

the mono PDO at the dermal layer for rejuvenation and fne lines.

The patient was evaluated post-operatively and patient's satisfaction was recorded. Post-operative instructions were given before discharging. Patient was recalled for revaluation after 3 days and after 1 month.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Botulinum Toxin and Fillers for Maxillofacial Esthetics**

Sainath Matsa

#### **33.1 Introduction**

#### **33.1.1 Facial Aesthetics**

The feld of cosmetology has steadily progressed over the past decade, and cosmetic procedures are moving towards a new era [1]. People are becoming more aware of the way they look, especially the face and are turning to medical and dental professionals to improve their appearance. Attractive facial aesthetics at any age has social and psychological benefts. Facial skin constitutes a major part in contributing to facial aesthetics. The skin is a refection of several body characteristics, of which gender is a prominent one [1]. Age, genetic, hormonal and exogenous factors can affect both skin structure and function and are responsible for differences between different men and women. This chapter gives the basics and advances in the feld of facial cosmetic and functional correction using Neurotoxins (Botulinum toxin) and Dermal Fillers.

#### **33.1.2 Facial Skin Physiology, Muscular Anatomy and Mechanical Properties**

In humans, skin including the epidermis and dermis is 1.428 times thicker in men than in women across 5–90 years of age [1]. However, women tend to have thicker subcutaneous fat. It has been found that, in men, it gradually becomes thinner with advancing age (12–93 years), whereas in women, the

S. Matsa (\*) Praseedha Clinic for Maxillofacial Cosmetic Surgery, Chennai, Tamil Nadu, India

skin thickness remains constant till the ffth decade, after which it tends to decrease [2].

Gender plays an important role in facial wrinkling. In men, the incidence of forehead wrinkles is higher than in women. However, the incidence of upper eyelid wrinkles does not appear to be infuenced by gender. Wrinkles in other parts of the face are found to be greater in men than in women, except above 65 years of age, when the incidence appears to equalise [3]. One study evaluated the skin morphology, elasticity and areas of sagging using photographs and a cutometer. The authors found that these were similar in both genders in the cheek region, but in the lower eyelids, sagging was more severe in males after middle age [4, 5].

#### **33.1.3 Facial Muscles and Their Actions**  (Fig. 33.1)

A good understanding of the action of the various facial muscles is important for precise application of botulinum toxin. The muscles and their actions are tabulated (Table 33.1).

### **33.2 Botulinum Toxin**

#### **33.2.1 Botulinum Toxin-Type A**

Botulinum Toxin type A was frst used on the face by Carruthers and Carruthers in the late 1980s [6]. Following studies in the 1990s about its cosmetic use, botulinum toxin was approved by the USA Food and Drug Administration (FDA). This led to a revolution in treating ageing skin in recent years [1].

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 691

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_33

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_33) contains supplementary material, which is available to authorized users.

©Association of Oral and Maxillofacial Surgeons of India

#### **Table 33.1** Facial Muscles and Their Actions

*Frontalis*—Raising the eyebrows; transverse wrinkling of the forehead

*Corrugator*—Vertical/oblique wrinkling of the forehead; draws the eyebrows together

*Procerus*—Pulls the glabellar skin in an inferior direction and causes transverse wrinkles

*Depressor Supercilii*—Pulls the eyebrow downwards on the medial canthal region

*Orbicularis Oculi*—Controls the sphincter of the eye

*Risorius*—Lateral movement of the corner of the mouth

*Orbicularis Oris*—Opening and closing of the mouth (sphincter action)

*Levator Labii Superioris*—Pulls the upper lip superiorly

*Depressor Anguli Oris*—Draws the corner of the mouth inferiorly *Depressor Labii Inferioris*—Pulls the lower lip downwards *Modiolus*—It's a union of muscles, situated lateral to the external

commissure of the mouth, allowing symmetrical perioral expression.

#### **33.2.2 Pharmacology and Mechanism of Action**

Clostridium botulinum produces an exotoxin. It is an anaerobic gram positive bacillus (Fig. 33.2) which forms spores. It has eight types of strains which are labelled alphabetically: A, B, C, D, E, F, G, and H [7].

Two types of strains, A and B, are available currently. These result from the modifcation of the protein structure that has been used for a variety of medical and cosmetic purpose. Botulinum Neurotoxin causes denervation of the motor neuron temporarily, in the treated muscle and selectively inactivates the nerve terminals by blocking the release of acetylcholine and the target protein SNAP25, [8] leading to a temporary and reversible blockade of cholinergic transmission. In the neuromuscular junction, the blockade of the release of acetylcholine promotes muscle relaxation to muscular palsy [9] (Fig. 33.3a, b, c).

#### **Reconstitution, Dilution and Dose:**

Botulinum Toxin Type-A is available as lyophilised powder that must be stored frozen −4 °C or lower. Reconstitution of the powder may be done using 0.9% Normal Saline solution, which is isotonic. Once reconstituted, the solution must be used within 4–8 h, after which the potency of the drug may be lost, and contamination of the vials may occur.

900kD BoNT/A complex contains:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 33.2** Chemical structure


Many commercial brands are available for Botulinum Neurotoxin–A, like Siax®, Botox®, Xeomin® and Dysport® and every brand has variation in its dilution.

#### **33.2.3 Indications**

Botulinum toxin injections may be used in the clinical scenarios highlighted in Box 33.1.

#### **Box 33.1 Indications of Botulinum Toxin**

	- cranial, lower facial, cervical, oromandibular.

#### **33.2.3.1 Contraindications** [10]

The use of Botulinum toxin injections is contraindicated in the following clinical situations:


#### **Patient Selection:**

In the present era, patients have increased awareness and knowledge about their health and skin conditions. They may be very ambitious and optimistic about the procedure and are likely to expect a high level of satisfaction with their personal appearance after the treatment. The goal of treatment is to achieve a better looking and natural appearance. The patients' psychological aspects and expectations should be understood and evaluated prior to the start of any cosmetic treatment.

#### **33.2.4 Injection Techniques** (Video 33.1)

The following techniques are used for injecting botulinum toxin into various areas of the face.


©Association of Oral and Maxillofacial Surgeons of India

5 U per point of the middle aspect of the muscle, represented in a big dots as given below in the fgure. Frontal injections and glabellar injections must preferably be done together, to avoid increased compensatory use of glabellar muscle, which are mainly depressors [12, 13]. The dose of the injections must be kept small enough to just weaken the muscle instead of producing total paralysis. This is because the frontalis is responsible for facial expressiveness, and total paralysis would cause brow ptosis [14, 15]. It is also important to preserve at least some frontal is muscle movement, responsible for facial expression and lift of the eyelids and brows.

(c) *Crow feet wrinkles Injection technique* (Fig. 33.6a, b): Three to four injections of Botulinum toxin-A may be

©Association of Oral and Maxillofacial Surgeons of India

Do not inject within 1 cm of the supraorbital rim ©Association of Oral and Maxillofacial Surgeons of India

administered lateral to the eye, in the 'crow's feet' region that radiates out from the lateral canthi. Around 8–20 U may be administered on each side [16]. The injection must be placed 1 cm lateral to the orbital rim and must be above the canthal angle, to avoid upper lateral lag. To achieve this, one can place a guiding fnger of the other hand at the lateral orbital rim. Owing to the superfcial location of the muscle, the needle need not be advanced deep into the subcutaneous tissue. Botulinum Toxin has a wide zone of effect, and therefore a superfcial dermal injection will minimise bruising, but will still give good clinical results [16].

(d) *Elevating Oral commissures and Smile line Injection technique* (Fig. 33.7): Depressor anguli oris is the muscle to be elevated for improving the smile lines. It is indicated in patients with inverted smile line (reverse smile line), which is caused by pulling the corner of the mouth inferiorly. To identify the depressor anguli oris muscle, the patient must frown and the muscle must be simultaneously palpated 1 cm lateral and inferior to the oral

Superficial veins ©Association of Oral and Maxillofacial Surgeons of India

**Fig. 33.6** (**a**, **b**) Crow feet wrinkles injection technique

commissure. Inject approximately 2–5 U deeply into the muscle on either side [16].


Do not inject < 1cm from the lateral orbital rim

Orbicularis oculi Lateral orbital rim

Alternative technique: Inject inferiorly on mandibular ramus ©Association of Oral and Maxillofacial Surgeons of India

**Fig. 33.7** Smile line correction

Levator labi superioris alaeque nasi

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 33.8** Gummy smile correction

placed along the lower border of the mandible, one fnger along the posterior border and one at mandibular angle. This may be done with the patient clenching, as

Intradermal injection ©Association of Oral and Maxillofacial Surgeons of India

**Fig. 33.9** Platysmal banding

this marks the perimeter of the muscle. While injecting bone should be felt by the needle and withdrawn slightly just above the bone and deposit 4–5 U along the marked lines. Depending on the volume of hypertrophy, around 20 U may be injected [16]. Over-injection at the masseter region may result in problems with bite or chewing.

(h) *Frey's Syndrome or Gustatory sweating Injection Technique* (Fig. 33.11): This is a condition in which mild to profuse sweating occurs in the cheek or malar area while eating. A diagnostic test called "*starch-iodine test*" [16] can be performed prior to injection of Botulinum toxin. Povidone iodine is applied over the cheek and corn starch is sprinkled. The patient is advised to eat, to stimulate the salivary gland and left to dry for a few minutes. The corn starch turns black in the area of sweating [16], and a grid is drawn along this area. Once the test is confrmed, usually 30–50 U is injected along the grid as shown. The botulinum toxin blocks acetylcholine, which is the neurotransmitter that stimulates sweating.

#### **33.2.5 Complications and Recommendations While Using Botulinum Toxin**


Masseter ©Association of Oral and Maxillofacial Surgeons of India

**Fig. 33.10** Masseteric hypertrophy

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 33.11** Frey's Syndrome


#### **33.3 Dermal Fillers**

#### **33.3.1 Role of Fillers in Facial Aesthetics**

Throughout the past decades, there have been major changes and advancements in the injectable preparations used for soft tissue augmentation. Introduced by Dr. Arnold Klein [1] in the 1980s, for lip augmentation, collagen has progressed to the broader concept of volumising the face and to correct the subcutaneous atrophy due to ageing and fat loss.

Following extensive clinical trials in the late 1970s, the FDA frst approved the use of bovine collagen in 1981, which greatly advanced the feld of soft-tissue augmentation. Over the past 10 years, several types of facial fllers have been approved in the United States and Europe, and there is a constantly evolving and expanding assortment of the dermal fller materials and devices for soft tissue augmentation [18].

Hyaluronic Acid (HA), which was introduced as a facial fller in 2003, brought about a much needed change from the allergies being reported due to bovine collagen [18]. Hyaluronic Acid is a member of the glycosaminoglycan family and a natural component of human connective tissue. The HA molecule is identical across all species and lacks a protein component, thus it has little to no potential for immunologic reaction in humans. It is composed of repeating disaccharide units, stabilised with cross-linked hydroxyl groups that bind water to create volume. This gives a plumped appearance to the skin. HA in the skin decreases with age and sun exposure, reducing the skin's water-binding capacity and turgor, ultimately leading to skin wrinkling and sagging [19]. HA can absorb up to 1000 times its molecular weight of water, and Hyaluronic Acid fllers volumise the face by replacing body Hyaluronic Acid and restoring hydration [5]. Studies have shown that hyaluronic acid requires less injection volume as compared to bovine collagen for optimal cosmetic results, and HA is also found to be more effective at maintaining the cosmetic correction [20, 21].

The U.S. Food and Drug Administration (FDA) has now approved various types of Hyaluronic acids, bio-stimulatory products like calcium hydroxyapatite and poly-l lactic acid, as well as polymethylmethacrylate as a substitute for fllers.

Fillers are categorised as permanent, semi-permanent and temporary. The majority of injectable fllers are temporary, lasting from several weeks to several months, although some reportedly last 9–12 months. Many of these processes require ongoing treatment to maintain the desired appearance [22].

#### **33.3.2 Classifcation of Fillers**

Based on their duration of action, fllers may be classifed as follows:

*Temporary (3–12 Months)* These are mainly used to replace collagen in the skin, which weakens with age and loses its elasticity. Collagen has three main sources—bovine, porcine and human. Bovine collagen is very similar to the human molecule and is widely used. It only has specifc differences in the end peptides (telopeptides), which are removed in processing, leaving a core protein similar to that of a humans [23]. Hyaluronic acid is the most commonly used Filler material of this category.

*Semi-Permanent (1–5 Years)* Calcium hydroxyapatite is one of the commonest semi-permanent fllers. It creates a stable scaffold for soft tissues to grow. Calcium hydroxylapatite may be injected into the deep dermis, where the microspheres are held in place until they are resorbed and collagen deposition occurs. This results in formation of non-scar-tissue type of collagen, which provides volume in the area under treatment [24].

*Permanent (>5 Years)* These are mostly synthetic implants, which are made of Polymethylmethacrylate (PMMA) microspheres. PMMA microspheres may be mixed with denatured bovine collagen and lidocaine, and suspended in a phosphatebuffered saline solution. Since PMMA is inert, it is well tolerated by the body and does not induce allergic reactions [25, 26].

#### **Preparation of the Patient before Injection of Fillers:**

The patient's face is washed gently to dry and disinfect the skin. This is done using propanol solution. Since the dermal fllers are very painful while injecting, application of the topical anaesthesia around the area of injection using EMLA (Eutectic Mixture of Local Anaesthesia) for 30–45 min prior or particular branch of Maxillary division or Mandibular division of the trigeminal nerve is anaesthetised using 2% Lignocaine as a local anaesthetic injection.

©Association of Oral and Maxillofacial Surgeons of India

#### **33.3.3 Dermal Filler Injection Methods** (Fig. 33.12)

Hyaluronic acid is available in syringes in a sterile packed container. These have 26–30 gauge needle, with a length of 1–1½ inches.

These are injected at the subdermal planes in various fashion which are mentioned in Box 33.2.

The following is a description of various techniques.

**Linear Threading:** In this technique, fllers are injected in a needle and thread fashion. The needle is inserted and withdrawn repeatedly along a straight line. It has two types.

1. *Anterograde Injection:* The fller is injected while the needle is being advanced, and the fller is therefore easily tracked in the front of the needle.

#### **Box 33.2 Dermal Filler Injection Methods**


**Depot:** In this technique, a small amount of the fller is deposited in the correct plane.

**Serial Puncture:** In a single wrinkle or fold, multiple closely spaced depot injections are placed.

**Fanning:** It is done through one point of entry and the needle is rotated like a fan in multiple directions, and the fllers are deposited in a retrograde way. It is important to stop injecting as the needle comes close to the insertion site in order to avoid build-up of fllers at the point of entry.

**Cross Hatching:** Injecting as multiple linear thread deposited in an X-shaped fashion.

**Grid:** It is injected as linear threads intersecting perpendicular to each other point of entry.

**Ferning: [16]** This is similar to retrograde injection. The needle is inserted on either side of the central tract, and the fllers are deposited in a branch-like fashion almost like the branches of a fern.

#### **33.3.4 Injection Techniques**

(a) *Glabellar and Forehead region* (Fig. 33.13a,b): The Glabellar region is the most prominent site for wrinkling and very well shown even in a mild expression. There are vertical lines of wrinkling, which result from contraction of the corrugator supercilii muscles, and horizontal lines which occur due to contraction of the procerus muscle. Before injecting, the patient should frown the brow and the needle is inserted at the subdermal plane and injected in a linear fashion and it is also deposited deep and parallel to the wrinkle. Small depots or serial puncture fashion of fllers are injected along the line of the wrinkles throughout its entire length. Gentle

Supraorbital artery and nerve

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 33.13** (**a**, **b)** Glabellar & forehead wrinkles

rub or massaging to be done to distribute the fller uniformly. In the case of bruising, icepacks can be used. Injecting into a vessel must be avoided as this can lead to the formation of emboli.


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 33.14** (**a**, **b)** Nasolabial fold injection technique

move within it along the entire lip margin. Dermal fllers injected in the body of the lips can augment, rejuvenate and improve the symmetry of the lips. Philtral columns can get fattened with age. These can be accentuated by injecting along the border of the vermilion and philtral region to give a more prominent philtrum and cupids bow with eversion of the lip. The philtrum may be pinched after injection to accentuate the ridges. Injections are generally placed superfcially in to the subcutaneous plane. Massaging or a gentle rub after injection helps to distribute the fller evenly. Injection may be performed in an anterograde fashion, from lateral to medial, and the fller can be tracked along the vermillion.

(d) *Tear Trough Deformity* (Fig. 33.16): Tear Trough is usually referred to as the crease at the medial segment of the inferior orbital region. As ageing occurs, the infraorbital rim becomes more skeletonised and depressed. To correct this sunken appearance, HA may be injected into the semicircular depression under the eyes. Normally a 30-gauge needle, 2.5 cm long, is used to inject in the dermal layer of the lower eyelid to avoid bruising, as this area is highly vascularised. The needle is then inserted upwards at an angle, till it reaches the top of the orbital rim. The fnger of the opposite hand may be used to direct the needle by positioning it at this point. The tip of the needle must touch the bone and its precise location must be verifed prior to injection. The fller is injected slowly and deeply into this area. Massaging may be done at the injected area to avoid irregularities. If the HA is deposited too deep, a "*Tyndall effect*" [16] may be observed. Hyaluronic Acid can occasionally increase fuid retention around the periocular area, and lead to infraorbital swelling, edema or discolouration in the medial portion of the orbicularis muscle. If this occurs, subcutaneous hyaluronidase injections may lyse the Hyaluronic Acid and reduce the swelling.

(e) *Injection technique to increase the cheek volume* (Fig. 33.17): In some patients, fat loss or volume defcit can cause cheek hollowing. The loss of buccal pad of fat causes wrinkled cheeks, exaggeration of nasolabial folds and jowling of the skin at the lower border of the mandible. The submalar region (below the zygomatic arch) and buccal region (lateral to the nasolabial fold) are areas that need attention. The injection technique should be administered in a grid or fanning pattern. The injections must be administered at the dermal–subcutaneous plane. Massaging after injection can help smoothen irregularities.

#### **33.3.5 Contraindication** [22]

Some of the most common conditions to be avoided for fllers include:


#### **33.4 Conclusion**

Botulinum Toxin Type A and Hyaluronic acid dermal fllers are very safe and effective under a trained physician or surgeon for therapeutic and cosmetic use. Wrinkles especially those which are located in the face and some asymmetries, mainly caused or worsened by the repeated contraction of facial muscles and ageing process can be effectively treated by these methods.

Proper knowledge of the anatomy of facial muscles and proper techniques are important to achieve predictable results and avoid complications. Informed consent for the procedure must be obtained from the patient after explaining the risks and the outcome, before commencing the treatment. Though Botulinum toxin and dermal Fillers give temporary results, they are safe and very effective in achieving aesthetic outcome.

**Disclosure** Author has no fnancial conficts to disclose.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 33.15** Injection technique for philtrum, lip line and the body of the lip. (**a**) anterograde flling (**b**) retrograde flling (**c**) both anterograde and retrograde flling (**d**) antero retrograde with fanning if necessary (**e**) depot and serial puncture flling (**f**) anterograde retrograde serial and depot flling

Pre periosteal filler along orbital rim

Tear trough deformity ©Association of Oral and Maxillofacial Surgeons of India

**Fig. 33.16** Tear trough deformity

Nasolabial fold ©Association of Oral and Maxillofacial Surgeons of India

**Fig. 33.17** Injection technique for hollowing cheeks

#### **Case Scenarios**

#### **Case 1** (Fig. 33.18a,b,c)

A 43-year-old female complaining of excessive tooth and gingival exposure on smiling. Clinical features (Fig. 33.18a): excessive gingival show on smiling normal lip length and normal size of the tooth. Treatment Plan (Fig. 33.18b1, b2, b3 and b4): locating the levator labii superioris muscle and injecting Botulinum toxin Type A with a dose of 5 U on both the sides. The injection point is located at the junction between lip and the ala of the nose. Post-operative fndings (Fig. 33.18c): no gingival show on smiling.

**Fig. 33.18** (**a**) Clinical features with excessive Gingival show. (**b1, b2, b3, b4**) Intraoperative. (**c**) Postoperative, absence of Gingival show

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 33.19** (**a**) Clinical feature with forehead wrinkling. (**b1, b2**) Intraoperative. (**c**) Post-operative, absence of Wrinkling

#### **Case 2** (Fig. 33.19a,b,c)

A 47-year-old male, complaining of excessive wrinkling in the forehead on looking upwards and frowning with ageing appearance. Clinical features (Fig. 33.19a): wrinkling and folds found on the forehead on upward starring and frowning. Treatment Plan (Fig. 33.19b1, b2): locating the frontalis muscle and injecting Botulinum toxin Type A with a dose of 5 U on both the sides at 3 different points marked and above 1 cm from the supraorbital margin. The injection point is located midway between supraorbital margin and frontal hairline. Post-operative fndings (Fig. 33.19c): absence of wrinkling.

#### **References**

1. Baran R, Maibach HI. DorisHexel Textbook of cosmetic dermatology. 5th edn; Chap 1,50,51—Skin size and Parameters, Botulinum Toxin, Soft tissue Augmentation Chap; Pg – 3,459,473.


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## **Hair Transplantation**

Sreedhar Reddy Pothula and B. S. Jayanth

#### **34.1 Introduction**

In the past few decades, maxillofacial surgeons have played a pivotal role in enhancing the aesthetic value of the face through many surgical and non-surgical procedures, with hair transplantation being one of the popular choices which has seen an exponential demand in the last decade. Though hair restoration procedures were being performed for many decades ever since Dr. Norman Orentreich in 1959 published them in the annals of the New York Academy of Sciences, there has been many advances to the originally described punch grafting which has become obsolete and has been replaced by the so-called micrografts via the two basic techniques of follicular unit transplantation (FUT) and follicular unit extraction (FUE). The success of the above techniques is in part attributed to the theory of donor dominance which postulates that the hair taken from the donor area of the posterior scalp will continue to grow without getting hit by factors which were responsible for the thinning out of hair in the frontal areas [1].

Apart from hair transplant being a promising procedure for male pattern and female pattern alopecia, it has been applied to other causes of hair loss too; traumatic and burn scars on hair bearing areas, alopecia following surgical procedures (i.e. Craniotomy, rhytidectomy procedures), redo hair transplantation, congenital reasons like cleft lip scenario. Currently the scope for hair transplantation is expanding with the demand from patients who want to strengthen a

S. R. Pothula (\*)

B. S. Jayanth (\*) ABMSS, Bengaluru, Karnataka, India

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_34

weak hairline, desire to lower the hairline or fx missing facial hair on the moustache, beard, eyebrow or eyelashes.

As the feld of hair transplantation continues to evolve at a breakneck speed with specialists from multiple specialities performing this scientifc artistry, it's all the more pertinent that we as maxillofacial surgeons are abreast of the current principles and practice of this hair restorative surgery.

#### **34.2 Surgical Anatomy**

An understanding of the surgical anatomy of the scalp is necessary to avoid complications and to optimise your performance for hair transplantation.

Scalp consists of fve distinct layers with the most superfcial layer being the skin which comprises of epidermal and dermal layers. These layers contain hair follicles, sebaceous and sweat glands with rich vascular supply. The second layer of scalp is made up of connective tissue, which is well vascularised and heavily innervated by sensory nerves. The deepest portion of the hair follicle, bulb and papilla, may extend through the skin into this layer (Fig. 34.1a). Thus, when obtaining donor grafts, effort should be made to incorporate the upper part of dermal layer to obtain the entire hair follicle. The third layer also called galea aponeurotica is a tendinous tissue connecting the two bellies of the occipitalis and frontal muscles. Loose areolar connective tissue is the next layer which contains numerous potential spaces, capable of great distension thus allowing for exceptional mobility of scalp. Unfortunately, these spaces are also capable of potential space for haematoma collection and spread of infections. The deepest layer of the scalp defnes the pericranium, which is analogous to periosteum throughout the body.

**34**

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_34) contains supplementary material, which is available to authorized users.

Oral and Maxillofacial Surgery, Pioneer Advanced Hair Transplant Centre, Bengaluru, Karnataka, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 707

708

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.1** (**a**) Hair follicle extending into dermis; note the layers of the scalp. (**b**) Arteriovenous supply of the scalp with sensory innervation. (**c**) Zones of the scalp

#### **34.2.1 Blood Supply and Sensory Innervation**

The arterial supply to the scalp arrives from branches of both external and internal carotid arteries. Branches of the external carotid artery in order from posterior to the anterior include the occipital, posterior auricular and superfcial temporal arteries. The supratrochlear and supraorbital arteries are branches of the internal carotid artery. The veins of the scalp follow the same basic network of the arteries and drain into the jugular veins (Fig. 34.1b). All of these vessels freely anastomose in the connective tissue layer of the scalp. Awareness and approximate location of the main branches are very important during the hair transplant surgery not only to avoid haemorrhage or haematoma but also to prevent ischemia to the follicles. Occipital artery which enters the scalp immediately above the external occipital protuberance at the superior nuchal line can easily be injured if depth control is not maintained. If arterial haemorrhage is encountered, electro cautery and suture ligation are adequate to secure homeostasis. Damage to vessels could likely lead to the formation of donor area scar.

Sensory innervation of the scalp arises from all three branches of trigeminal nerve antero-laterally with the forehead getting its supply from the supraorbital and supratrochlear branches of the ophthalmic division, while the anterior temporal scalp is supplied by the maxillary division and the mandibular division goes onto supply the temporoparietal zone of the scalp through its auriculotemporal nerve. The spinal cutaneous nerves of the cervical plexus (c2 and c3) come to supply the area posterior to the auricle via the greater and lesser occipital nerves. These nerves are found in the connective tissue just superior to the galea.

#### **34.2.2 Zones of the Scalp**

Typically, the areas of male pattern hair loss are horseshoe shaped and are divided into three zones [2] (Fig. 34.1c)


The temporal fringe is the lateral hair zone present on the sides of the scalp anterior to the tragus of the ear and posterior to this is the parietal fringe.

The frontotemporal apex is the area usually devoid of hair at the junction of the lateral frontal hairline and temporal fringe. This coincides with the deepest point of the recession on the forehead and is aligned with the lateral canthus of the eye.

#### **34.2.3 Microanatomy of Hair**

Hair consists of a living part under the skin extending into the dermis known as follicle and a non-living keratinised part above the skin, the so-called hair shaft (Fig. 34.2). The shaft has three further layers namely the outer protective cuticle, inner cortex and in certain cases the medulla forms the core, and they mainly help in protection and anchorage of the hair.

The growing structure of the hair is the follicle with the upper part being constant and consists of the top infundibulum at the opening of sebaceous gland and isthmus in the middle where the piloerector muscle comes to insert. The lower part of the follicle known as the bulb is very vital as it's the one involved with regeneration and most of the stem cells are located here. Hence, while implanting holding, the graft above or beside the bulb is vital to ensure sustenance of regenerative potential.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.2** Microanatomy of the hair

#### **34.3 Terminology**

The unique language of hair transplant surgeons consist of a few common words to communicate within the speciality [3] (Box 34.1).

#### **Box 34.1 Hair Transplant Surgery: Terminology**

*Follicular unit graft (FU)*: The natural Bundle of hair strands consisting of one, two or three hairs woven within a single unit and held by connective tissue elements as the follicle. The graft containing two or three follicular units becomes a multi follicular unit graft.

*Micrograft*: The follicular unit which has single hair graft within it is referred to as a micrograft, and the same is preferred for frontal hairline implantation.

*Minigraft*: The follicular unit which has more than a single hair graft and houses four to six hair grafts prior to cutting with microscopes are minigrafts.

*Follicular unit density*: It's the number of follicular units per cm2 .

*Hair density*: It's the number of hairs per cm2 .

*FUT*: The grafts are obtained from the harvested strip through slivering and dissection of individual follicles under magnifcation.

*FUE*: The grafts are obtained individually in the donor area one at a time utilising a punch and handheld extractor.

*Stick and place implantation*: Refers to implantation made immediately as the recipient site slit is made with a needle or blade.

*Pre slit implantation*: Refers to implantation made after all the recipient site slits are made with a blade or needle.

*Coronal slits*: Refers to slits oriented along coronal from side to side.

*Sagittal slits*: Refers to slits oriented along sagittal plane from front to back.

#### **34.4 Growth Cycle and Hair Loss**

Hair is cylindrical, outgrowths on the skin made up of keratinous flaments. The normal human scalp contains between 100,000 and 140,000 follicles with hair being arranged in follicular units, small groups of 1–4 hairs each. There are approximately 50,000–60,000 follicular units on the human scalp.

Testosterone is the main regulator of hair growth with the androgens binding to receptors in the dermal papilla infuencing the growth. Human hair does not grow constantly and evenly but grows in phases and in cycles which are reproducible. Anagen is the growing phase of hair that accounts for 85% of the hair growth, during which hair grows at 0.5 inch per month for up to 10 cm per year with adequate blood supply providing nutrients and minerals to the hair. This phase lasts for anywhere between 3 and 6 years. As long as this phase persists, the hair stays on the scalp and is genetically determined. Anagen is followed by catagen and the later phase onset signals the end of active hair growth. During this transitional phase which lasts for 1–2 weeks, the production of hair stop and hair follicle start to shrink in size and nearly 2–3% of the hairs are in this phase. Telogen is the fnal phase of the hair cycle where the aged hair fall out and new ones push themselves out of the skin. This fnal phase lasts for nearly 3 months with around hundred hairs being shed per day and nearly 10–15% of the hairs are in this phase at any point in time (Fig. 34.3).

People often confuse with hair fall to hair loss. Hair fall is common in every individual. Around 10–20% of total hair will be under shedding process. That hair will grow back in 3 months. On average 80–60 hair strands fall is considered as normal.

Male pattern hair loss or androgenetic alopecia as the word suggests is a result of both androgens and genetic factors which work together causing the clinical effect of baldness [4]. Though there are many reasons for hair loss, androgenetic alopecia is the most common reason and accounts for 95%. Fortunately, it can be treated with hair transplant surgery. The diagnosis of androgenetic alopecia is supported by a family history of hair loss, although a positive history is not always identifed. There is a slightly greater incidence of having a positive history on the mother's side but the inheritance of male pattern hair loss can come from either side of the family.

In androgenetic alopecia, there is change of hair from terminal hair to vellus hair. There happens to be a gradual evolution of this pattern, with each subsequent cycle of the new hair being fne and thin leading eventually to various grades of alopecia. It initially starts with the frontal hairline recession and regression, followed by loss of more temporal hair and simultaneous thinning of the vertex hair. Norwood classifed approximately 7 different types of male pattern hair loss. Identifcation of these types is key to an understanding of proper planning of hair transplant surgery.

Testosterone gets converted to dihydrotestosterone (dht) both systemically and in the process of intrafollicular conversion under the infuence of the enzyme 5-alpha reductase leading to its binding with androgen receptors of the follicular cells in genetically predisposed men leading to inhibition of protein synthesis by shortening the anagen phase, thereby producing fner hairs with shaft becoming thinner; this stunted hair follicle growth leads to miniaturisation of follicles till they become extinct establishing balding [5].

#### **Box 34.2 Basic Requirements for Hair Regrowth**


Clinical studies have given us an understanding that hair can be grown back if the following four things are ensured (Box 34.2):

Hair loss is not a disease but a condition where anagen or the growth phase reduces and the telogen or fall phase is extended. This forms the basis of hair loss in alopecia conditions other than androgenetic alopecia. The factors leading to hair loss could stem from internal/external factors.

*Internal Factors* There are many factors which internally lead to defcient states harming the hair growth. A few of them which are relevant today are iron defciency, calcium defciency, zinc defciency, general debility, anaemia, hypothyroidism, defciency of the fat soluble vitamins, thyroid problems, insulin resistance, metabolic disorders like gout and PCOD, prolonged illness, emotional turmoil following surgery and individuals with seborrheic scalp.

*External Factors* The lifestyle and environmental factors do infuence the hair health and growth cycle. The common causes are smoking including passive smoking, stress, alcohol intake, lack of sleep, crash dieting, fad diets, high-protein diet, exposure to extremes of heat or cold, less intake of fuids, poor scalp hygiene, dust, pollution, fumes and exposure to endocrine disrupting chemicals.

#### **34.5 Classifcation**

The most popular classifcation of the male pattern hair loss is the Norwood classifcation system (1975) which is a refned version of the original Hamilton system (1941) [6].

#### **34.5.1 Norwood Classifcation** (Fig. 34.4)


Basically, in the above classifcation, the two areas of hair loss—a bitemporal recession and thinning crown gradually enlarge and coalesce until the entire front, top and crown of the scalp are bald.

**Fig. 34.4** Norwood classifcation of male pattern alopecia

To regain the crowning glory, medical treatment gives good results up to type 3 patients while hair transplantation is the only choice for patients between types 4 and 6.

Routinely, clinicians come across variations of the classifcation which fall outside the Norwood classifcation, they are as follows: Differential use pattern alopecia, diffuse and patent alopecia.

#### **34.5.2 Classifcation of Hair Loss in Women**

The Ludwig classifcation (1977) uses three stages to describe female pattern genetic hair loss (Fig. 34.5).

Type I (mild), type II (moderate) and type III (extensive). In all three Ludwig stages, there is hair loss on the front and top of the scalp with relative preservation of the frontal hairline. The back and sides may or may not be involved.

In Ludwig type I, there is early thinning that can be easily camoufaged with proper grooming. Type I patients have too little hair loss to consider surgical hair restoration.

Women with type II hair loss have signifcant widening of the midline part and noticeably decreased volume. Hair transplantation may be indicated if the donor area in the back and sides of the scalp is stable.

In Ludwig type III, there is a thin, see-through look to the top of the scalp. This is often associated with generalised thinning over the entire scalp. Often patients that have progressed to this stage have too little donor hair to make surgical hair restoration worthwhile.

All women experiencing hair loss should have an accurate diagnosis made, preferably by an experienced dermatologist. This is particularly important since the diffuse hair loss that women typically develop, can occasionally be caused by a number of treatable medical conditions. Regardless of the extent or cause of hair loss, only women with stable hair on the back and sides of the scalp are candidates for hair transplantation.

Other infrequent alopecias observed among the patients visiting hair clinics are as follows:

*Alopecia areta*: it's an autoimmune disorder which starts with small round and punched out areas with no hair. Lesion has very smooth skin and not even a single hair is present in the lesion.

*Alopecia totalis*: there is total loss of scalp hair.

*Alopecia universalis*: there is total hair loss in the body including the eyebrows.

**Fig. 34.5** Ludwig classifcation for hair loss in women.

©Association of Oral and Maxillofacial Surgeons of India


#### **34.6 Medications for Hair Loss**

Only 2 drugs have been approved by FDA and have proven their effcacy in the management of hair loss with good success.

#### **34.6.1 Minoxidil**

This is a direct hypertrichotic drug, which was initially approved as an antihypertensive agent and was found to have side effect of hypertrichosis. Today, it is available as an over the counter drug with 2% formulation for women and 5–10% formulation for men as topical solution and gel. It improves hair count, weight and growth of hair. Post transplantation too it has been found to decrease the shedding of hair and enhanced the time to onset for hair growth. According to few studies, minoxidil acts as a vasodilator by opening up the potassium channels and thereby enhances the vascularity of the hair bulb which in turn promotes hair growth. However, the exact mechanism is unknown. This topical product needs to be applied to the scalp and not the hair and patients need to be informed about the initial increased shedding of weak hair in the frst 4–8 weeks. Further, the patients need to be counselled to apply the product twice a day to maximise the effcacy and to wait for a timeframe of at least 4–5 months prior to seeing the results.

#### **34.6.2 Finasteride**

Finasteride is a drug which is used only in men for reversal of miniaturised hair follicles. This drug is a competitive inhibitor of the enzyme 5-alpha reductase which blocks the conversion of male hormone testosterone to dihydrotestosterone, and thereby works on the pathogenesis of androgenetic alopecia. It is to be taken orally once a day daily at 1 mg. Finasteride can cause loss of libido and oligospermia in few individuals. However, this side effect is reversible once the drug is discontinued.

Other medicines like Dutasteride though being a potent inhibitor of 5-alpha reductase is not that popular in the market as it has got adverse effects. Few natural products like saw palmatto can be used in young individuals who refuse to take fnasteride.

#### **34.6.3 Cyclical Therapy**

It entails giving vitamins with calcium supplements on a single day, followed by iron and mineral combination product on one other day of the week and fnally amino acid blend; the three regiments are also advocated that their intake be on alternative days as different nutrients and the daily dosing is avoided. The basis of this therapy is that hair requires nutritional support during their anagen growth phase and also for its maintenance; without nutrients, hair cannot get support and the stimulated hair growth to demonstrate disappointing outcomes. This therapy is the result of pioneering work on the role of nutritional supplements in hair growth.

Platelet-rich plasma (PRP) is an autologous biological modifer which has many concentrated growth factors in it and has demonstrated good results in reducing hair loss and has shown to enhance hair counts. It is prepared in a threestep process where blood is drawn, processed and injected into the scalp. It is injected into the scalp once every fortnight for 4–6 sittings and this can be combined with the standard therapy.

#### **34.7 Clinical Consultation**

It is important to begin the consultation by knowing the general health of the patient with a focus on endocrinal conditions affecting hair namely the thyroid disease, any uncontrolled diabetes, polycystic ovarian disease in the case of females and also enquiring specifcally about family history of hair loss, past medical management, understanding personal hair care regimen and any past hair transplants done.

The next focus of the clinician during consultations should be on the expectations and motivation levels of the patient trying to drive home the message that it's a progressive condition especially in younger patients who are demanding and want a low hairline. It's important to have a family member during consultation and ensure that they understand that any future hair loss is understood and you are only trying to frame the face. The pattern of the hair loss also needs to be well documented.

The donor site assessment will verify the presence of any white hair, check the elasticity of the scalp, the density of the hair follicles per square centimetre, note the calibre of the hair (thick vs. thin), presence of curly or straight hair, rule out any existing scars and skin pathology including dandruff and infections.

The assessment of the recipient site will focus on the quality and quantity of remaining hair, ascertaining the grade of balding and the pattern of hair loss, previous results of hair transplantation, the skin to hair contrast, direction of the existing hair and existing skin condition. Based on the priorities of the case and having assessed the areas requiring hair transplantation, the number of follicular units required per square centimetre (around 30/cm2 ) is calculated to arrive at the number of follicular units to harvest.

#### **34.8 Concept of Hair Transplantation**

Hair transplantation as performed today is basically microfollicular unit transplantation and few clinicians call it as hair restoration as there are many methods to achieve the results.

In the early days, hair transplant concept started with fap rotation techniques requiring procedures to be performed under general anaesthesia. These invasive techniques did not gain popularity as the results were not satisfying and the procedures left disfgurement in few individuals. Later on during the evolution of techniques, macro and micrografts being 5–6 mm in size were introduced which were harvested with biopsy punches and the resulting grafts were implanted. These plug like grafts being unnatural in appearance gave a classical doll's hair appearance after growth and got phased out with further refnement of hair transplant procedures.

By around 1963, follicular unit transplantation or strip technique was introduced which became a workhorse of hair transplantation until recently and is still considered to be the gold standard method for hair restoration. In the year 2002, Rossman and Bernstein refned the punch method of harvesting the follicles and named it follicular unit extraction which has seen an exponential growth in the recent years and is today the most popular technique of hair transplantation.

The principle behind hair transplantation is quite simple. The hair that grows on the back and sides of the scalp tends to be permanent in most of the individuals. These occipital and parietal hairs are resistant to androgenic alopecia and are used to implant into the frontal or vertex area which will continue to grow as long as occipital hair grow, but in few individuals with advanced grades even these donor hairs can be miniaturised and lost. That's the reason as to why anticipating the future hair loss is most important factor while planning hair transplant procedure.

Hair transplant as a procedure is successful only when hair loss is stabilised, as it will not stop further hair loss. We as surgeons can only relocate and transfer few strong follicles from donor area to recipient area without increasing any new follicle per se. Many young patients who are frustrated by taking medicines over a period of time will seek hair transplant procedure as a remedy, which is an absolutely wrong decision for the clinicians to encourage. It is imperative on the part of the clinician to stabilise any ongoing hair loss before embarking on the hair transplantation, with individuals below the age of 25 years being denied the scope of the procedure.

Hair transplant surgery demands good planning, great surgical skill and good aesthetic sense on the part of the clinician, as hairs grow in specifc direction and angulations for the given area of the scalp, and grafts should be placed in a way which should look natural and cover the scalp gaps thus achieving good density.

Most of the patients would like to know if the results are permanent with guaranteed results. Here, it's the astute clinician who should make all efforts to ensure that patient understands the concept of the hair transplant and the future consequences too, rather than simply promising the results.

The basic concept in hair transplant surgery is one of camoufaging technique which makes them look better rather than taking them back to their crowning glory days of their past during their younger days.

Patient should understand that he may still loose hair further and get worse with his genetic predilection to go bald and it's a progressive process. Hair transplant will only help him to maintain hairs which are aesthetically acceptable for his age and few individuals may require future sessions too.

#### **Preparation Prior to Hair Transplantation**

Routine blood test consisting of Complete blood count, glycaemic levels, prothrombin time and serology are done for every case. In patients with any underlying medical conditions, further investigations as deemed necessary for the case are done and a medical ftness is obtained from the physician.

All patients are advised to stop topical minoxidil at least a week prior to transplant to avoid bleeding hampering the progress of the case.

Photographs and consent for the procedure are obtained as a part of standard operating procedure for hair transplantation.

Consenting for the procedure should focus on detailed information of the procedure with clarity given on the results that can be obtained explaining the pros and cons of the procedure, their complications and outcomes. Alternative suggestions should also be given including no surgery, use of camoufage techniques and patients being on only medicines. Adequate time should be given to discuss and understand the proposed procedures. Finally, the proposed treatment plan with the fees proposed should be mentioned in the consent along with written preoperative and post-operative instructions.

The treatment plan formulated needs to account for the quantum of hair to be transplanted, the hairline design, the areas of high priority on the scalp, patient commitment and compliance.

#### **34.9 Techniques and Description**

#### **34.9.1 Follicular Unit Transplantation (FUT)**  (Box 34.3) (Video 34.1)

FUT is also called strip method or stitch method. It's a gold standard method in hair transplant procedures till date though it's an old method [7]. The modern-day FUT is mainly harvesting a single strip, though earlier few doctors practised with multiple blades to obtain multiple strips which are obsolete now.

Strip method includes taking or harvesting a strip of the skin layer from the donor area usually from the occipital area of the head below the occipital protuberance and above the nape of the neck in the so-called safe zone for harvesting.

Strip measurements are variable with 30 cm being the maximum length and 1–2 cm width depending on skin laxity of the patient. However, the length and width are variable according to planning arrived at during the consultation with the patient as per the indication of the case. At times we have to limit strip width to 1 cm if the skin laxity is limited. Usually a strip of 30 cm in length and 1.5 cm in width will give around 2000–3000 grafts depending on the hair density of the individual.

#### **Box 34.3 FUT**


#### **34.9.1.1 Assessment of the Donor Hair**

Hair transplant outcomes will greatly depend on the donor hair quality and quantity [8]. The important factors that the clinician has to bear in mind are as follows:

1. The number of grafts that are present per square centimetre

Few individuals have thick density being good or best donors (Fig. 34.6a) while a few have sparse density being poor donors (Fig. 34.6b) with the number of grafts per sq cm varying between 25 and 65 grafts on an average in healthy Indian adults. It further varies from person to person and sometimes from area to area in the same individual. Usually, occipital area has thick density whereas parietal area has less density. Good observation of the grafts in the donor area is most important for the surgeon to achieve good results.

2. Number of follicles present per graft

This is highly variable with 2, 3 or 4 follicles being present in Indian adults whereas a few have only one or two follicles per graft. The presence of reducing follicles per graft is a sign of the progressive nature of the blading process.

3. Donor skin area

Few individuals have large donor area as their scalp size is larger while a few individuals have donor bearing area which is smaller (Fig. 34.7a, b). This entity will decide the number of grafts that is available for harvesting.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.6** (**a**) Good/best donor area based on hair follicular density. (**b**) Poor donor area based on hair follicular density. (**c**) Donor area skin laxity testing to ascertain the strip width planned for FUT

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.7** (**a**) Large head with more surface area at donor zone. (**b**) Small head with lesser surface area at donor zone

#### 4. Shaft diameter

Individuals with thick shaft diameter will have better density and the outcome of the results is enhanced.

5. Skin laxity (Fig. 34.6c)

In individuals with better skin laxity, we can harvest more grafts by FUT method by going for wider strips in a single session, whereas the same skin laxity may not have any signifcance with the FUE method.

Patients who present with straight hair end up optically having less density because light can pass through hair strands and skin becomes visible especially if the hair is black and is contrasting against a fair skin background. Whereas presence of curly and course hair in an individual with dark complexion can give the illusion of thick density.

#### **34.9.1.2 Donor Site Preparation and Anaesthesia**

Trimming is essential in the donor site to harvest the strip and the team member in charge of the preparation can ensure trimming the hair to 3 mm all over the scalp. Few surgeons prefer the procedure without trimming so as to reduce the downtime for the patient's social acceptability. But trimming will ensure better visibility and accessibility to the surgeon while performing the suturing with attention to detail to ensure minimal scarring along the strip harvest. Following the trimming, the next step is to wash the scalp with betadine solution. The clinician should ensure that preoperative photos, consent for the procedure, recording of baseline vitals of the patient and his weight is recorded prior to the preparation of the donor site.

The harvesting of the strip is done with the patient in prone posture following the standards of care with an iv line, monitoring of the vitals with a 3 parameter monitor, and following a dose of prophylactic antibiotic under aseptic conditions. Next, the donor area strip length and width to be harvested are marked out based on the skin laxity tests and depending on the individual's follicular density per square cm.

Once the marking is done, local anaesthesia is administered to the donor area, usually preferring feld block in that area. Injecting the local anaesthetic in the lower border of the strip would provide suffcient anaesthesia to the feld above.

#### **34.9.1.3 Preparation of Local Anaesthesia**

Hair transplant procedure is time taking and lasts around 6–8 h. Lidocaine usually is a very safe anaesthetic with a duration of action lasting between 90 and 120 min and therefore we need to add a long-acting drug-like bupivacaine for hair transplant procedure. Combination of the above would work better for 8–10 h and the overall dosage should not exceed the maximum permissible as per the weight of the individual. The local anaesthetic solution used is typically as follows:


#### **34.9.1.4 Instruments for the Strip Procedure**

Variscore blade (Fig. 34.8) is useful to have control on the dimensions of the strip and it gives the option to adjust the strip width by adding or reducing the metal spacer plates. Each metal spacer plate comes with thickness of 2 mm and 1 mm and, for example, if we need a strip with width of 1.3 cm, then we need to add 6 plates of 2 mm and 1 plate of 1 mm. The variscore blade has added advantage of depth control while making incision and can accommodate two surgical blades. Usually, for scalp, we can use number 15 surgical blades.

Prior to the incision marking, the strip dimensions are done. Most of the surgeons make straight incision, which may lead to scar. It's always better to follow Langer lines of the skin which ensures less scars with the strip incision looking like a crescent shape with the end tapering off. Strips which are as long as 30 cm (Fig. 34.9) in length run from above one ear to the other ear. It's always recommended to

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.8** Variscore blade -popular blade handle for FUT

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.9** Strip harvested prior to slivering

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.10** Wound margins prepared for trichophytic closure

place the incision at or just below the external occiput area as the follicles here are considered permanent. It is indeed not good to go too low below the external occiput as we may end up in big blood vessels. After the initial indentation of the incision is done with variscore blade, it is later followed up by the use of BP blade number 15 and the incisions are made very carefully to reach up to 3 mm beneath the follicular depth with some amount of subcuticular fat around it, while we ensure that we do not cut the galea. While making the incisions, care is taken to prevent slicing of the follicles at the skin margins and the fap is raised from one end to the other using gentle yet deft strokes with the blade.

Good illumination and haemostasis can help to raise strip with minimal damage to both the follicles and vessels in the vicinity. Damage to the vessels is most common if proper tumescence is not attained and can lead to bigger scar and shock loss of hair in the donor area. Any adventure into the galeal layer can lead to haematoma and chances of spreading infections through emissary veins.

Haemostasis is achieved prior to closure by using bipolar diathermy; the scalp wound is irrigated with normal saline and a double layer closure is performed with vicryl 2.0 (TS 2404, 3/8 circle, cutting edge) for the inside and a prolene 3.0 (nw800, 3/8 circle cutting edge) for the outer skin (Fig. 34.11a, b). The strip that is harvested is preserved in cold saline on a petri dish at 4 °C.

#### **34.9.1.5 Trichophytic Closure**

Trichophytic closure (Fig. 34.10) involves trimming of the upper and lower edges of the skin which facilitates the hair to emerge through the scar ensuring that we will give aesthetically acceptable scar to the patient (Fig. 34.12b) Wound closure done without the above clinical manoeuvre leads to poor scar (Fig. 34.12a), which is quite obvious.

Post-operative care of the wound is important. Antiseptic creams are optional if the donor site wound is washed with clean water or ns on a daily basis. In our experience, suture removal is recommended on 11th post-operative day to avoid wound gaping or wound dehiscence.

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

#### **Variable Strip Technique**

This will help us to get maximum grafts with less tension along the scar leading to a better scar. Most of the individuals have thick density in the occipital area and lesser density in the parietal area and any misjudgement will lead to poor wide scar in the parietal areas. Here, by using variable dimensions of the strip technique (Fig. 34.13), we can target for more grafts with least possible scar. In this technique, the strip width is more in the occipital area than compared to the parietal area as illustrated in the image below.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.13** Variable dimensions of the strip marked out for harvesting

#### **34.9.1.6 Slivering**

Slivering is a process where the strip is sliced into small bits of tissues with rows of hair follicles in them, through meticulous deft handwork akin to the baker slicing the bread loaf into thin slices. It is the frst step of the separation of grafts from the strip while avoiding any transection of the graft. Higher magnifcations should be used to perform this important step for which a few clinics are using stereoscopic microscopes while the others manage with normal 10× magnifcation. It should be done simultaneously while the surgeon performs the wound suturing to save the crucial graft holding time of around 6 h.

At the end of this step, we get slivers which are ready for the separation process (Fig. 34.14). The separation process is separating individual grafts from the sliver. For the separation process, we need more trained technicians as it is cumbersome exercise and needs great attention to detail to avoid any form of trauma to the graft being obtained with an obvious fght against time.

For the separation process, we need to use 3× magnifcation which can be done on a sterilised wooden spatula or an acrylic illuminated sheet.

Wooden spatula would give us good resistance to cut the grafts whereas acrylic sheets will be slippery. Advantage of the acrylic sheet is we can illuminate from below, which is easy for separating the grafts. The separation process is noth-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.14** Slivering and separation of grafts from the strip in FUT

ing but getting rid of the excess fat around the grafts and making the grafts slender in a pear shape or tear drop shape. Care is to be taken to ensure that we do not denude the roots and little fat is left behind for survival of the graft through plasma imbibition. All skin has to be trimmed and removed from the graft and fnally these prepared grafts are preserved in cold normal saline around 4–8 °C temperature.

While separating the grafts, we would get single, double, triple follicular unit grafts, and care is exercised to maintain the follicular unit (Figs. 34.15 and 34.17a), as it is natural to ensure better survival. These are segregated further in different bowls and are used up for implanting starting with single units for the frontal hairline and progressing onto multiple follicular units as we go posteriorly in a progressive manner.

#### **34.9.2 Follicular Unit Extraction (FUE)**  (Box 34.4) (Video 34.2)

In this technique, we extract the individual follicles one graft at a time with the help of small punches. Also known as no stitch and no cut method, it's minimally invasive procedure

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.15** Separated follicular units

compared to the FUT. FUE gained popularity in recent years because of its ease of doing and being less invasive with minimal downtime for the patient. Initially, FUE was introduced with manual punches which was more tedious and time consuming limiting the number of grafts that could be done in a session [9]. Current advances with motorised punch have improved the pace and its effectiveness in harvesting more grafts. Though many different motors and punches are available in the market, normal dental micromotor with straight hand piece would suffce to perform FUE (Fig. 34.16a, b).

Punches are made up of either titanium or stainless steel with the diameter of the punch ranging from 0.6 to 1 mm, with 0.9 mm being suitable for Indian scalp. The advent of FUE has expended the scope of harvesting follicles from other sites of the body wherein 0.6 or 0.7 mm punches are useful for beard site and 0.8 or 0.9 mm punches have been suitable for chest hair harvesting, respectively.

#### **Box 34.4 FUE**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.16** (**a**, **b**) FUE instruments: micromotor, straight handpiece and punches

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.17** (**a**) Follicular units and their natural arrangements. (**b**) Comparison – FUE grafts on the left which are lean and slender versus FUT grafts on to the right which are bulkier

Punches are available as dull, sharp, serrated and oscillating type. Normal dull or sharp punched would be suffcient to perform FUE. On an average one punch can be used to harvest around 1000–1500 grafts.

This latest motorised technology has made surgeons' job easy and in experienced hands we can harvest around 800– 1000 grafts in 1 h, provided patient's skin is favourable.

Being a blind procedure, this is technique sensitive and is associated with a steep learning curve requiring more concentration. It is performed under 3× magnifcation controlling the punching around the hair graft while maintaining depth and angulation which is very vital to harvesting the grafts. The punch should get down to epidermis and dermis junction not going beyond 4 mm from the skin. Surgeon should always analyse the angle of exit of the hair and be parallel it prior to the punching. Acute angles of the grafts would lead to diffculty in punching and lead to not only bigger punch holes but higher transaction rates. Most of the Indian skin is favourable for FUE procedure because of thicker skin types. The follicles obtained by FUE are comparatively slender and devoid of extra adventitious tissue in comparison to the FUT follicles (Fig. 34.17b).

#### **34.9.2.1 Blades**

They can vary in size and shape from being thin sharp blade to having a pointed chisel as in the case of sp90 which is one of the popular blades for pre slit technique. Today, the surgeons have a choice of customising the blade with commercially available tools and can use a square or tapered blade as per their choice.

#### **34.9.2.2 Needles**

Standard 19 gauge hypodermic needle is preferred for making the graft recipient sites while the same can be achieved with solid core needles eliminating epidermal implantation.

#### **34.9.2.3 Limitations of Follicular Unit Extraction**

FUE has an important role to play in hair transplant because it can reach the areas where strip cannot reach to harvest grafts. When we plan second session, FUT may not be possible in unyielding skin types. In poor candidates where donor areas of the scalp have poor hair quality, FUE can be used to target beard and body hairs. FUE like any other procedure is associated with a few disadvantages like comparatively more GTR (graft transection rate), especially in curly hair types and in these few cases graft yield is abysmally low wherein the surgeon will have to convert the case to strip technique. Follicular splay is another situation where hair roots are placed apart which causes diffcult extraction. In case of scattered grafts too, the punch may tend to damage more grafts while harvesting and would not be an ideal situation to continue harvesting with high graft transection.

#### **34.9.2.4 Hairline** (Fig. 34.18a, b)

The hairline design and location are the most critical factors in the success of hair transplantation, for which one should understand the concept of facial thirds. Till the age of third decade of life, the anterior hairline at the midline is located at a distance equal to the middle third height of the face from the glabella, adding additional 1 cm in length to it with each passing decade of life to take the hairline upwards and backwards to give a matured look to face considering the progressive nature of hair loss. The frontotemporal apex is the deepest point of the anterior hairline laterally as it merges with the temporal hairline and is located along the lateral canthus of the eye [10].

It is to be borne in mind that the hairline anteriorly is not a straight line but an irregular one having peaks and troughs making it look like a coastline with the front two rows made

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.18** (**a**, **b**) Hairline design and natural looks

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.19** Recipient site slits

up of single follicular units and gradually it progresses to double and triple follicular units to give the density. The central core or frontal tuft area gets the maximum density of hairs implanted to enhance the strength and aesthetic value of the hairline thus created.

#### **34.9.2.5 The Recipient Sites Preparation and Implantation**

Recipient sites are prepared (Fig. 34.19) to receive the grafts by making slits in the skin with either 19 gauge hypodermic needles or sp 90 blades (Fig. 34.20) or other microblades which are of 1–1.1 mm in width. This step could be done

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.20** sp 90 blade used for recipient site preparation

prior to implantation for all the grafts (pre-slit method) or individually for each graft while simultaneously implanting it (stick and place method).

Slits made with blades tend to give more natural looks when compared to needle implantation (Table 34.1). As a prerequisite to facilitate implantation, the site needs to be trimmed short while the remaining hairs guide us in the direction and angulation of the implantation. Proper tumescence will allow us to expand scalp so that we can place more grafts in the given area while also reducing any damage to the neurovascular bundle and enhances visibility.

The slits are performed in the area with proper direction (converging forwards), depth (follicular length for the given patient) and angulation (15° in the front −45° as we approach the crown part of the scalp).

Once the slits are done, implantation is done by using jeweller's forceps (Fig. 34.21), which are pressure graded. This is also called 2 forceps technique as one forcep is used to locate the slit while the other one is used to implant the graft into the slit. The grafts are to be held above the bulb or beside it where the dermal fat is held.

Implantation of 3000 grafts by forceps would need around 3–3.5 h approximately (Fig. 34.22a).

#### **34.9.2.6 Implanters**

Few surgeons use implanters (Fig. 34.22b) which can hold the graft in it and all you have to do is to eject them into the site at the desired direction and angulation. Technicians will preload the graft into the implanter. Implanter can be used

**Table 34.1** Advantages and disadvantages of blade versus needle for slit creation


with pre slits or without pre slits made in the scalp. However, implanters tend to create a circular slit which may lead to pitting kind of scars at the base of the graft after growth. They need extra hands for the procedure and come at an extra cost too.

#### **34.9.3 Combi Technique** (Fig. 34.23)

This is a combination of FUT and FUE in a single session. Combi technique is recommended when we need more grafts as in anything over and above 3500 follicles in a single session. In this technique, the strip is frst harvested

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**Fig. 34.21** Jeweller's forceps used for implantation

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**Fig. 34.22** (**a**) Immediate view of a case post implantation. (**b**) Implanters used for implantation

and then the FUE is performed above and below the strips in the same sitting before implanting. Advantages of this procedure are that the surgeon can reduce the strip length and still can obtain more grafts thereby reducing the strip length and the resulting scar. However, it requires an experienced surgeon and well-trained team to execute the procedure.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.23** Combi technique post-operative view

#### **34.10 Post-operative Care**

Immediately after the procedure, the heaviness, numbness or tightness may be there for a few hours. There is also some swelling on the forehead and temple area due to the tumescence and surgical insult and the resulting swelling is normal. Patients are allowed to sleep on the back or on the sides but are not allowed to sleep on their tummy as otherwise the swelling tends to gravitate onto face and eyes. Patients should be asked to massage the forehead from the middle to the sides for 5 min every hour for frst few days. Rarely some patients may feel momentary dizziness especially while standing up from the lying down position on the procedure table.

There is some oozing of blood-stained fuid from grafted site as well as in donor area (both in case of strip or FUE). Bending forward of the neck can stretch the stitches and can initiate some more oozing from the stitches therefore keeping the chin up is recommended.

Patients are restricted to perform any contact sports/gymming for a period of 12 days and should avoid swimming for up to 3 weeks. They should also not get to feld work under the sun for frst 3 weeks. Patients who ride a bike are allowed to wear a helmet after a period of 4 weeks. Topical minoxidil can be restarted in the transplanted site after a waiting period of about 15 days post-operatively. Patients are also forbidden from riding a bike or driving in an open vehicle for up to 2 weeks.

After the procedure, antibiotics and analgesics are provided for 5 days. The donor and recipient sites may or may not be bandaged. If bandaging is preferred, a non-adhering betadine pad is placed over the operative sites with several layers of fattened gauze sponges over them to hold the betadine pad in place as the scalp is wrapped with clean bandage using to two to three 4-inch gauze rolls. Crepe bandage can

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**Fig. 34.24** (**a**–**d**) Outcome following hair transplantation

be used over it. The dressing is removed the following morning, and the scalp and each graft are clean meticulously by gently dabbing with a cotton swab with normal saline. Patients are advised to sprinkle or spray normal saline over the grafts every 3–4 h for 8–10 days. Suture removal is performed on 11th day and is not applicable for FUE. Initially for 10 days the grafted area should be washed without rubbing the grafts. Whereas after the above period, grafted area can be washed and patients can rub the grafts. Most of the grafts will be shed by 12–20 days which is a common phenomenon, one need not to worry about it falling off.

#### **Regrowth and Results** (Fig. 34.24a–d)

Summary of events following a hair transplant.

Immediate after a hair transplant, there will be mild blood excretion and oozing.

1st day scabs (nothing but dried blood) will form and continue forming for the next few days.

After 4 to 10 days you will notice itching. This is normal, but do not scratch or pick on the transplanted areas.

After 10 days your scalp will be cleared of all scabs.

After 11–20 days your new implanted hair will shed. Now your new follicles are in its dormant (sleeping) stage. It's time to watch and wait.

Pt must be aware that a lag phage exists before hair growth is initiated. After approximately 4 months, the telogen phase to the implanted grafts ends and anagen begins. Complete growth can be seen only after 8 months and hair continue to grow until 12–14 months.

#### **34.11 Complications**

Able professionals should manage any adverse outcomes by minimising the damage and help achieve the desired outcomes with low morbidity. Fortunately, today the follicular unit hair transplantation is a safe procedure with low rates of complication when performed with care [11].

#### **34.11.1 Complications in Preoperative Phase**

Overexpectations of the patients are the major cause of complications and arise due to hasty or incomplete consultation and is better addressed with more than one consultation to assimilate the requisite information with the help of informative brochures, websites and discussions with the clinician to arrive at realistic outcomes especially in the younger patients who happen to be unclear and lack maturity for comprehending the results; in such cases, it's better to keep them on medical line of treatment till they become practical in accepting the results. Any individual with body dysmorphic disorder and Norwood vii patients where you would not make much difference would count as poor patient selection by the clinician. In case of ongoing hair loss, the clinicians should not be tempted to promise full coverage or high density infuenced by the advent of current medicines as the patients may change their minds and stop the intake of medicines over a long period of time, eventually resulting in inappropriate placement pattern and lack of donor site for harvesting. Clinicians should not be further infuenced by the patients' demand for low unaesthetic hairline, or be drawn into performing mega sessions arising out of patients' demand and be careful in choosing the donor material in the middle of the back and sides of the permanent fringe avoiding any slanted scars or scars visible in scanty donor hair bearing areas.

#### **34.11.2 Complications in Surgical Phase**

1. Pain:

Patients who are counselled appropriately and are provided with a relaxing ambience generally experience minimal discomfort. In-depth local anaesthesia achieved through precise nerve blocks and ring blocks administered with a long-acting drug-like sensorcaine and taking help of vibrating devices while injecting the solution slowly will go a long way in enhancing the comfort levels. Anxiolytics should be prescribed by the clinicians to patients who are apprehensive about the procedure.

2. Bleeding and popping:

Optimising the health of the patient prior to the surgery results in blood pressures being within normal limits. Adequate tumescence consisting of saline and epinephrine has to be injected below the dermis to allow the surgical feld to be lifted away from the bleed vessels and then the clinician has started the procedure after 15 min will have minimal bleeding. Too much of tumescent in the recipient site can be a cause of popping, though clinician cannot eliminate popping as pre slit technique can minimise the issue.

3. Bad hair direction:

Clinicians should plan appropriately to maintain the direction and exit angle of the hair that mimics the natural growth. Keeping the grafts with a few millimetres of hair will allow the clinician to ascertain the angle during implantation.

4. Hiccups:

Due to the irritation of the aberrant branch of the vagus nerve, patients can have hiccups through the procedure.

5. Poor graft quality:

A good team leader will constantly supervise to ensure proper handling of the follicles, which will minimise trauma to the follicle resulting from transaction, manipulation, desiccation, oxygen starvation and crushing of the graft [12].

#### **34.11.3 Post Surgical Complications**

#### 1. Donor site effuvium:

Hair in the growth phase can fall rapidly post transplantation due to temporary lack of oxygen during surgery resulting in loss of hair variably along to suture line when signifcant blood vessels are cut. Any such hair loss will be noticeable around the third week postoperatively and leads to embarrassment to the surgeon. If the donor area can be raised above the blood vessels with good volume of tumescence, the above complication is rarely encountered.

2. Infection:

This is a very rare complication seen today given the standard asepsis precautions followed and is rarely encountered where the patients are not given adequate post-operative instructions especially in cases of tight donor area closure and in patients with compromised immunity.

3. Dehiscence:

A poor surgical technique associated with bad suturing, harvesting wide strips, performing tight closures or resulting infections and necrosis can lead to dehiscence.

4. Dysesthesias:

Today it's no longer a complication thanks to adequate use of tumescence which will lift the hair follicles above the neurovascular bundles.

5. Scars:

This unavoidable outcome can be prevented by following the basic principles of surgery with accurate approximation, closure without tension, by using double layered closure, trichophytic technique and avoiding resolvable suture for closing the skin. Donor scars also occur due to improper donor assessment prior to the surgery. Skin laxity test will help us to evaluate the skin laxity so that we can limit the strip width. At times we may need to consider variable width dimension to reduce the tension in the wound, usually where occipital area skin laxity is more and parietal area skin laxity is less. So we can consider more width at occipital area and less width at parietal area. If skin has less laxity, we can consider FUE.

Any hypertrophic scar can be managed with steroid or injection and later implanting hairs with FUE.

6. Forehead swelling and ecchymosis:

Based on the laxity of the skin in the frontal area and the trauma induced by the slit making process, swelling occurring at 3–4 days post hair transplantation can be mitigated by including some steroids in the la solution, applying pressure bandage and some digital massage across the forehead.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.25** Folliculitis post hair transplantation

7. Surgical effuvium:

This is similar to the donor site effuvium which results in the anagen hairs going into telogen phase and falling out around the second or third post-operative week and regrowing with the grafts. Preoperative use of minoxidil solution tried 1 month prior to the procedure is recommended to prevent the above complication.


It's very important to avoid the above complication in the frontal hairline which could otherwise be unacceptable and are easily preventable by avoiding deep placement of the grafts as in the case of pitting and too superfcial placement of the grafts as in the case of tenting.

10. Poor growth:

This can be attributed to poor handling of the grafts resulting in physical and biological trauma to the grafts associated with dehydration of the follicle, crushing of the follicle during implantation, thermal insult and prolonged holding time outside the body.

The incidence of complications may be reduced by avoiding mistakes by the team in general (Box 34.5) and those related to the technique, specifcally graft survival (Box 34.6).

#### **Box 34.5 Frequently Made Mistakes Made by Team**


#### **Box 34.6 Factors Afecting Graft Survival**


#### **34.12 Current Advances**

Futuristic developments in the feld of hair transplant need to focus on the current lacunae in the procedure and revolves around the availability of limited donor supply and the duration of the procedure.

Low-level laser light therapy has been approved by FDA as a device to stimulate the hair growth in the 650–800 nm spectrum. Home-use scalp brush or helmets with laser technology are available which use the pain-free technology to stimulate epidermal stem cells in the hair follicle to move the follicles into anagen phase.

Automation of the FUE process with the use of robotics has shown to reduce the follicular transaction rates and improve the harvest speed, resolving the issue of skills possessed by practitioners. Artas and neo-graft are devices which have glamorised the feld by involving robotic technology, but the running expenses and need to create sites and manually implant follicles need to be solved in the coming days.

If hair can be cultured from the scalp biopsy, then the patient would not need to donate hair by going through a painful procedure, by cloning hair we can create unlimited supply of follicles and avoid ration of hair. Current state-ofthe-art research promises that the technology would get transferred from bench side to the bedside in a few years from now.

#### **34.13 Role of a Maxillofacial Surgeon**

A maxillofacial surgeon makes a good hair transplant surgeon as they are well trained in surgical anatomy of the head and neck with a detailed knowledge of fap design and through in-depth working knowledge of the local anaesthesia management. They have a great aesthetic sense with artistic hands and are well versed with cephalometric analysis which comes handy in judging facial proportions and hairline placements, further most of them are very well adapted to handling the rotary handpiece from their formative training. Maxillofacial surgeons are well trained exclusively in head and neck surgery for 3 years and are competent at managing wounds and infections, thus justifying their qualifcations to perform hair transplantation alongside plastic surgeons and dermatologists.

#### **34.14 Conclusion**

Surgeons who deal with aesthetic surgeries on the face need to have a good range of skills to deal with all aspects of beauty which are defned by the individual elements. The most important of them all being framing of the face like a photo frame with hair transplantation which will allow us to focus our vision on the fner elements of the facial beauty be it the nose, lips, eyes, teeth, jawline or a good smile. If surgeons follow the principles of hair transplantation surgery, they will create patients with high degree of satisfaction using the micrografts of FUE or FUT procedure. This sophisticated form of art will bring a sense of gratifcation to oral and maxillofacial surgeons by embracing it as a tool along with all other tools at his disposal.

#### **34.15 Case Scenarios**

#### **Case Scenario 1** (Fig. 34.26)

Figure 34.26: male pattern baldness—Norwood classifcation 4.

Treatment: FUT method with 2850 plus microfollicular grafts transplanted.

#### **Case Scenario 2** (Fig. 34.27)

Figure 34.27: male pattern baldness class 5.

Treatment: 4000 follicular units transplantation done through Combi technique involving both FUT and FUE in the same session.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 34.26** (**a**–**f**) Case scenario 1

**Fig. 34.27** (**a**–**d**) Case scenario 2

©Association of Oral and Maxillofacial Surgeons of India

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Ear Reconstruction**

Paritkumar Ladani

#### **35.1 Introduction**

The human ear is a vital and distinctive feature of the face, and therefore, its deformity confers a signifcant impact on self-esteem and mental development in affected patients. Microtia is the commonest congenital ear malformation. The management of ear malformations can be challenging, because of its complex 3D structure. To achieve proper reconstructive results, it is frst essential to understand the basic anatomy and architecture of the ear [1]. Materials used for reconstruction of the ear include autogenous cartilage, alloplasts like silicone, Medpor, and osseointegrated materials. Surgical reconstruction of the ear with autogenous grafts is a unique marriage of science and art [2]. Good results depend not only on surgical skill but also on conforming to the basics of plastic surgical principles and tissue transfer. The gold standard for external ear reconstruction even today is the use of autogenous cartilage frameworks.

#### **35.2 Incidence and Etiology**

The incidence of microtia is around 1 in 10,000 live births. It appears to be more frequent at higher altitudes, especially above 2000 m, due to the low oxygen levels. The condition is 2.5 times more common in boys than in girls and more commonly affects the right ear. Unilateral cases are four times as common as bilateral ones. Aural atresia is found with microtia in 75% of cases. Microtia usually occurs if there in an abnormality in the embryologic development of the six auricular hillocks. These develop at 4–12 weeks of

P. Ladani (\*)

Oral and Maxillofacial Surgery, Swiss Cleft and Craniofacial Centre, BSES MG Hospital, Mumbai, India

gestation. Microtia may be associated with other birth defects. The exact cause behind the abnormal embryologic development remains unknown. However, certain teratogens like isotretinoin and thalidomide have also been implicated in this [3].

Microtia may occur in association with other malformations, including facial nerve weakness, cardiac defects, urogenital defects, hemifacial macrosomia, and spine defects. It has also been associated with syndromes like Goldenhar syndrome and Treacher-Collins syndrome [4].

#### **35.3 Surgical Anatomy**

It is crucial to understand the external auricular anatomy and architecture before proceeding with reconstruction (Fig. 35.1a). The ear has certain defnite structural elements. The overall outline of the ear is oval shaped and is slightly fattened posteroinferiorly. A distinct line can be made out that defnes the helical rim, arising from its root and ending at the crus helicis. Another line forms the concha, which consists of the tragus and antitragus. The fossa triangularis is the fnal defning structure that defnes the ear (Fig. 35.1b). A complete understanding of these structures allows the microtia surgeon to use these basic components to reconstruct the complex three-dimensional structure.

When viewed in the horizontal plane, the ear is divided into three parts. The superior portion starts at the top of the helical rim and ends at the helical root at the superior border of the concha cymba. The midportion starts at the upper border of the concha cymba and ends at the upper aspect of the antitragus. The lowest portion extends from the tip of the lobule to the superior border of the antitragus. The length of the ear is defned as the distance between the highest point (supraaurale) and the lowest point (subaurale). This may vary between patients in accordance with the differences in the shape of the patient's face and their lobule characteristics. For instance, the ear lengths vary from 55 mm to 65 mm, with a

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_35

**35**

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_35) contains supplementary material, which is available to authorized users.

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 731

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 35.1** Normal external auricular anatomy and architecture

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 35.2** Relation of ear to nose and facial plane

mean of 62.4 mm in males and a mean of 58.4 mm in females. The width is approximately 55% of the ear length and is around 35.5 mm in males and 33.4 mm in females. The protrusion of the ear, also called the auriculocephalic angle, ranges from 15° to 20°. This is the angle between the mastoid skin and the posterior surface of the auricle. Again, this may show variation between patients. However, this angle should remain the same in both the normal and the reconstructed ears [3]. The angle between the vertical axis of the face and the longitudinal axis of the ear is referred to as the ear inclination. It must be measured with the patient oriented to the Frankfort horizontal position. This is around 24° with the face, but is 32° in relation to the nasal dorsum (Fig. 35.2).

#### **35.4 Classifcation**

There are four grades of microtia, depending on the severity. These are as follows:


There is another simplifed classifcation, in which microtia is divided into the lobular type (ear remnant and lobule **Fig. 35.3** (**a**) Lobule-type and (**b**) conchal-type microtia

©Association of Oral and Maxillofacial Surgeons of India

are present) or conchal type (presence of concha, external canal, and tragus with lobule) (Fig. 35.3).

#### **35.5 Evaluation and Management**

The management of a child with microtia should ideally be discussed with parents shortly after birth, to reduce parenteral stress and offer them reassurance. The audiologic testing should be performed before discharge. In cases of unilateral microtia, treatment is not urgent because the other side will have normal hearing. Treatment can be thoughtfully planned after consulting with relevant specialists. However, in bilateral cases, brainstem auditory-evoked response testing must be performed as soon as possible so that the child can be ftted with a bone-conduction headband. The microtia surgeon can discuss about all the possible option with the family, including observation, autologous costal cartilage, alloplasts, and prosthetics. Each method of management has a different timing, and therefore, all optins must be discussed at an early stage. In addition, the microtia surgeon must also coordinate ear reconstruction with auditory management, so that the timing of the hearing correction may be optimized [4].

#### **35.6 Timing**

Timing of repair is governed by both physical growth and psychological consideration. The ears reach much of their mature size by age 7. Generally, by the age of 6, cartilage is suffciently developed to provide an optimal primary framework. However, the older the child, the more cartilage is available for reconstruction. On the other hand, waiting for cartilage growth must be weighed against the psychological and social effects of the missing ear on the child. Studies show that psychological effects usually manifest only around the age of 7–10. However, by age 6, most children are aware of the problem and want to get it corrected [3]. The timing can also depend on the method of reconstruction chosen. The Brent method, which requires less cartilage, may be performed as early as 6–7 years of age. On the other hand, the Nagata method can be done only after 10 years of age, when the chest measures at least 60 cm at the xiphisternum. This is because it needs larger amounts of cartilage [1].

#### **35.7 History**

Tanzer et al. frst established the technique for total auricular reconstruction. The technique was modifed by Brent, who utilized more defned surgical techniques such as fabrication of the framework and reconstruction of the tragus using composite chondrocutaneous grafts. These techniques were three stages and four stages, respectively. Nagata and Park outlined techniques that involved just one or two stages for ear reconstruction [5]. Allolastic implants were tried since the 1960s. Initially, silicone implants were used, but these were associated with complications such as implant failure following minor trauma or abrasions. In 1993, Wellisz reintroduced the prefabricated alloplastic implant for microtia reconstruction. This was constructed from PHDPE [6].

#### **35.8 Principle and Planning** (Video 35.1)

The Microtia surgeon should begin with proper planning and achievable goals for successful auricular reconstruction. It is important to discuss the details of surgical procedure and limitation of surgical repair with the family during preoperative consultation. The surgeon must prepare the family for multiple stages, long preoperative and postoperative care, and complications. The reconstructed ear will possess some defcits as compared to the normal ear and will be less fexible and elastic. The reconstructed ear can also be prone to complications, including hematoma, poor healing, infection, or skin breakdown. These complications can compromise the defnition and contour of the reconstructed ear [3].

If the patient has coexisting anomalies, such as clefts, early surgery must be done frst to correct these. For instance, in cases of Treacher Collins syndrome and other frst and second branchial arch defects (craniofacial microsomia, Goldenhar's syndrome, etc.), the bone reconstruction must be achieved frst, with scars peripheral to the proposed ear [7].

The precise positioning and dimensions of the reconstructed framework will defne the end result of the surgery. The reconstruction must be symmetrical to the contralateral ear in the unilateral case. In bilateral cases, the parent's ear is used as a reference. Visual examination may not be reliable, and it is essential to make exact measurements, after properly positioning the patient. For an ideal position, the superior extent of the ear must be placed parallel to the Frankfort's horizontal plane, at the level of the lateral brow (Fig. 35.4). The root of the helix may be positioned at the level of the subnasale, approximately one ear-length behind the lateral brow. Measurements must be taken carefully, particularly from the lower one-third of the face, in cases of facial asymmetry (seen in about 88% of patients with microtia). The asymmetries can range from mild differences in gonial posiP. Ladani

tion to full-blown hemifacial macrosomia and can lead to inaccuracies in measurement [3].

The fnal outcome also depends on the skin quality around the ear area. If the skin is scarred, natural expansion cannot take place, and the fnal ear may have a poor defnition. In such cases, supplemental tissue in the form of faps (e.g., temporoparietal fascia fap) may be considered to augment the supple skin envelope. In general, skin elasticity varies for each individual, and this can infuence the fnal defnition of the ear [8]. In cases of tight skin, a lower-profle 3D framework (1 mm) may be created, to avoid strain on the skin.

#### **35.9 Simulation Training**

The surgeon must obtain enough training in plastic and reconstructive surgery, including skills such as gentle fap dissection, delicate wound closures, and skin grafting, to achieve optimal outcomes. In addition, surgeons must be familiar with precise carving that is required for forming the 3D framework for the ear. Potato, carrot, or pumpkin can be used to learn and perfect the art of sculpting a framework [8]. Silicone dental impression material provides a convenient replica of costal cartilage, as it has the same consistency and texture. An exact replica of the rib cartilage and a precise template of the ear will allow the simulation to mimic the clinical situation. Creating the framework can be done using wood carving instruments. These techniques aid the novice surgeon in improving their results during the actual surgery [9].

**Fig. 35.4** Future position and size of ear

©Association of Oral and Maxillofacial Surgeons of India

#### **35.10 Template**

Preoperative photographs should be obtained, and measurements of the normal ear must be obtained when the patient is awake. The surgical template is prepared from radiograph flm using normal ear as a guide. In the beginning, an outline of the helical rim, lobule, antitragus, tragus, and conchal bowl is created from the opposing ear as the frst template [3]. This template needs to be reversed to plan the ipsilateral ear. Another mirror image template is created based on the frst one, which is smaller in dimension. This would allow for the extra thickness following insertion of cartilage under the skin (Fig. 35.5). The inferior pole on the framework is created much smaller in size, to accommodate the transposition of the earlobe. If the patient does not have usable earlobe tissue, this can be carved into the lower end of the framework. A second template is created, this time minus the helical rim. This template is used as a guide for creating the base of the framework from the sixth and seventh ribs, after which

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 35.5** Final surgical template of ear made from x-ray flm

the rim of the helix can be added. The templates must be chemically sterilized prior to intraoperative use. A third template, made along with the frst, has markings at the lateral canthus of the eye and commissure of the mouth. This allows ideal framework positioning and orientation. The distances marked on the template must be verifed by measuring the distance between the lateral canthus and the root of the helix [3].

#### **35.11 Auricular Reconstruction Using Autologous Rib Cartilage**

#### **35.11.1 Harvesting Rib Cartilage**

For harvesting the rib cartilage, an incision, 4–5 cm long, is placed obliquely on the ipsilateral side, at the level of the synchondrosis of the sixth and seventh ribs [10]. The incision is carried down through the muscle, to expose the costal cartilages. It is safer to harvest the cartilage without perichondrium because leaving the perichondrium behind offers one more layer of protection to pleura. The perichondrium also allows for the regeneration of the cartilage/bone matrix. Removing perichondrium can not only offer less protection but also lead to signifcant depressive chest deformities [8]. After harvesting is complete, intercostal nerve blocks may be administered. Closure of the muscle and deep fascial layers is done, and a large piece of cartilage may be banked in a subcutaneous pocket for the second stage [10]. Smaller cartilage pieces may be diced and placed inside the sutured perichondrial pocket, where it can aid in cartilage regeneration (Fig. 35.6).

#### **35.11.2 Framework**

The supporting framework is a living sculpture that serves as the foundation for the repair. Rather than carving the framework to exactly mimic auricular cartilage, the surgeon must make allowances for the abnormal skin coverage that is present. These limitations include skin-volume shortage and greater skin thickness, both of which produce excess skin tension. To prevent the fattening of the ear's rim that this tension might cause, one must carve a somewhat thicker and more substantial helix. This exaggeration of the cartilaginous framework will compensate for the thickness of the overlying skin. The 3D framework must be at least 9.5–10.0 mm high in the case of primary reconstruction and further augmented by 1.0–2.0 mm for secondary reconstruction [8].

©Association of Oral and Maxillofacial Surgeons of India

The cartilaginous framework is constructed from the synchondrosis of the sixth and seventh ribs (Fig. 35.7b, c, d). Cartilage wedges from these ribs are used to create the helical sulcus and the triangular fossa. The helix itself is formed from the eighth rib because it is longer. If additional length is required, the ninth rib can also be harvested (Fig. 35.7e) [10]. While carving the helix, it must be ensured that superior portion is higher than the inferior portion. The part of the helix that will be continuous with the lobule must be trimmed at the lower end, until it is long enough to receive the lobule attachment. The constructed helix is then affxed to the basal cartilage. On doing this, an outward inclination of 10–15° is maintained, at the middle one-third of the ear. The entire length of the lower part of the basal cartilage, at the outer end, is trimmed [5]. The foating rib cartilage that is used to create the helix must be thinned on its outer convex surface. This causes the cartilage to warp in a favorable direction and creates an acute angle that resembles the helix. This cartilage is then fastened to the body of the framework with 5-0 Stainless steel suture. The thickest parts of the remaining segments of cartilage are used to create the rest of the auricle, namely, the antihelix and antitragus-tragus complex, which surround the conchal bowl (Fig. 35.7f). The highest point of the antihelix is the middle, and this slowly tapers down to the helix. The superior and inferior crura are created, at the slope toward the lowest portion of the base frame. Enough space must be secured between the upper helix and superior and inferior crura, in order to accommodate the skin envelope. Otherwise, an effect of continuity between 2 crura and helix is created, which is undesirable [8]. The components of the framework are then assembled and secured together using 5-0 stainless steel wires. To achieve a snug ft, a small incision is placed in the cartilage and the wire is pulled gently toward the incision without burying it [10]. The position of the antihelix within the antitragus must be high, and trimming must be done at a lower level toward the superior and the inferior crura. In order to augment the antihelix, cartilage may be added in a vertical manner near the conchal area.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 35.7** (**a**) Armamentarium for carving, (**b**–**d**) preparation of base of the cartilaginous framework from the synchondrosis of the sixth and seventh ribs, (**e**) helix prepared from eighth rib cartilage, (**f**) antihelix and tragus, and (**g**) Final framework

This gives an effect of deepening of the concha. The antihelix is also trimmed in the region of the scaphoid fossa, so that it develops a slight inclination that resembles the natural convolution. Finally, the surfaces of the entire framework must be tapered smoothly tapered, and block-like corners must be removed, to ensure that the covering skin fts on smoothly (Fig. 35.7g). Throughout the process, isotonic saline solution is used to irrigate the cartilaginous framework. This helps preserve chondrocytes. The use of rotary and power tools must be avoided to prevent chondrocyte damage [7].

#### **35.11.3 Skin Pocket**

A pocket must be created within the skin in a meticulous fashion. This will provide proper vascular covering to receive the framework. As per the level of the lobular remnant, the level of the incision line for rotating the lobule may be determined. A small part of the lobular remnant is transposed posteriorly and separated from the microtic remnant. Then, the lobule is dissected and rotated to create a pocket that will accommodate the caudal end of the cartilage framework. This causes the lobule to be brought down and results in a smooth interface between the lobule and the framework. Creation of the skin pocket preserves the subdermal vascular plexus. The amount of dissection (at least 2 cm beyond the outline) must be wide enough to allow proper draping of the skin faps over the framework with minimal tension. Any cartilage, if present in the vestigial remnant, is removed. Meticulous hemostasis must be achieved [5]. An incision is placed at the posteroinferior border of the vestigial remnant, and the cartilaginous framework is placed in the subcutaneous pocket. The tail end of the framework is inserted into the lobule frst, followed by suturing of the outer incision. In order to let the skin adhere to the framework, two polyethylene drains with multiple perforators must be inserted beneath the framework. These are secured to the skin using 5/0 nylon sutures. A syringe (50-cc) may be connected to the drain. After fnal suturing of the subcutaneous pocket, the skin fap is approximated, and the piston of the syringe may be fxed in activated position using two wooden tongue depressors (Fig. 35.8) [5]. If skin blanching is noticed at this stage, the pocket must either be enlarged or the framework must be inserted at a lower position. The use of pressure dressings must be avoided as these can compromise the vascular supply. The entire reconstructed ear must be layered in petrolatum gauze, which must be placed loosely and left in place for 3 days [3]. The syringe with the activated piston may be changed frequently in the postoperative perio, ensuring that proper tension is maintained. The drains may be removed on the fourth or ffth postoperative, provided that the volume of fuid drained is less than 1-cc. Petrolatum gauze may be left in place until suture removal, on the sixth postoperative day [5].

©Association of Oral and Maxillofacial Surgeons of India

#### **35.11.4 Second Stage**

The second stage of surgery involves elevating the auricle from the head, which creates the auriculocephalic angle. This procedure should ideally be performed 6–9 months following the frst stage. In the conventional method, the incision lies several millimeters away from the margin, and reconstructed ear is gently lifted from the base. Care must be taken to preserve connective tissue on the undersurface of the ear, as well as on the bony foor. The posterior part of the auricle and the skin defect overlying the mastoid are grafted with skin. Since the ear lacks skeletal support, it contacts the mastoid skin and is not elevated. This creates a narrow space, which may be diffcult for the patient to clean [8].

In the Nagata technique, the second stage is more complex than the conventional one. This involves the following steps: (1) separation of the auricle from the mastoid, (2) The banked subcutaneous rib cartilage or an alloplast is used to create a wedge-shaped block, which is placed underneath the auricle, (3) A temporoparietal fascia (TPF) fap is then harvested to cover the posterior part of the auricle, and (4) A split skin graft harvested from the scalp to cover the fascial fap. Scalp skin is preferred as it has better color match as compared to groin skin (Figs. 35.9 and 35.10) [8].

#### **35.11.5 Complications**

• During the harvest of Rib Cartilage

The two commonest complications at this stage are pneumothorax and atelectasis. If detected intraoperatively, pneumothorax can be easily treated and may not require chest tube placement. Positive pressure ventilation is used after irrigating the wound to see if there is any leak. If there is no leak, the wound is closed in layers. If a leak is seen, it indicates the presence of pneumothorax. In this case, a red rubber catheter is inserted into the pleural opening to which a syringe is attached to this to evacuate residual air. Following this, the chest may be closed and an intraoperative chest radiograph is asked for to rule out residual pneumothorax. If this is absent, the wound may be closed, the catheter may be removed and follow-up may be done with serial flms [3]. Atelectasis is best prevented by frank preoperative preparation of the patient and vigorous postoperative respiratory therapy.

• Skin Flap Necrosis

The frst 10 postoperative days are critical to check for any skin fap necrosis. It is essential to achieve a balance between the thickness of the skin fap and the size of the pocket with the contouring of the cartilage framework. To prevent skin necrosis, it is advisable to minimize or completely avoid the use of epinephrine in the fap. The status of vascular supply can be tested by placing the framework in the pocket, activating the suction drain, and observing any for blanching along the rim of the helix. If blanching is present (indicating vascular compromise), the size of the pocket may be enlarged until blanching disappears. If needed, the skin supply may be increased by placing a tissue expander 2 months prior to insertion of the framework and skin adhesion [1]. If skin necrosis is observed, it must be attended to immediately, as it can cause infection of the underlying cartilage **Fig. 35.9** Ear reconstruction in hemifacial microsomia associated with microtia. (**a**) Preop and (**b**) Postop

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**Fig. 35.10** Ear reconstruction after traumatic amputation of upper half of ear. (**a**) Preop and (**a**) Post op

©Association of Oral and Maxillofacial Surgeons of India

and framework resorption. The damage can be minimized by covering with a local skin fap or fascial fap (Fig. 35.11).

• Infection

This is uncommon in the autologous reconstruction. If it occurs, along with appropriate systemic antibiotics, vigorous irrigation of the surgical site must be done.

• Cartilage Resorption

If there is either ischemia or infection, there are chances that the cartilaginous framework can get resorbed or deformed. This can also occur if the skin envelope is too tight, especially at the hairline border. To avoid this, dissection of the skin pocket around the hairline must be done carefully. Any tight fbrous band that exists along the hairline must be released.

• Wire Extrusion

If any wires extrude from the framework, they can easily be removed at the outpatient facility. It is necessary that the wire must be removed as soon as extrusion is noticed, and the patient/family must be educated accordingly. Otherwise, there are chances that the exposed wires can cause resorption of cartilage around the wire.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 35.11** (**a**) Necrosis of skin at near suture line, (**b**) debridement and marking for local fap, and (**c**) fap in situ

#### **35.12 Auricular Reconstruction Using Alloplast**

The material used for creating framework has been a subject of debate and research. Autologous costal cartilage is still the most preferred material in microtia repair. However, some surgeons consider using alloplasts because of the following advantages.


The ideal alloplast for auricular reconstruction should have the following features: cost-effectiveness, ability to be implanted safely, ability to resist infection, and capability to undergo customization to resemble the contralateral normal ear. To date, more than 40 different materials have been used for creating the auricular framework. These include ivory, nylon, wire mesh, and silicone. Silicone was thought to show good results since it could mimic the fexibility and form of the native ear cartilage. However, it had a high rejection rate, especially when placed under thin skin faps. pHDPE (Fig. 35.12) is a modestly fexible, robust enough to withstand microtrauma, and easily shapable and allows soft tissue ingrowth. This permits it to be protected against extrusion and infection. It also allows targeted drug delivery to the implant [11].

#### **35.12.1 Technique**

It is crucial to assess the age of patient, dimension of contralateral ear in the case of unilateral microtia, and the dimensions of their gender-matched parent's ear preoperatively for achieving equal dimensions between the normal ear and the reconstructed pHDPE ear. The ear created must be adult sized as the alloplast does not increase in size.

The vascular Doppler is used for marking superfcial temporal artery. The incision is given in the postauricular area few millimeters behind the new helical rim of the microtic ear to approach TPF fap. Incision is extended in a curvilinear fashion over the TPF fap to improve the exposure and also helps to harvest the distal fap of recommended length. Other approaches may be used, including an Y incision (Fig. 35.13a), which extends superiorly from the mastoid area, and the Z incision, (Fig. 35.13b) which exposes the TPF. These approaches also allow better access to the fascia.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 35.12** Porous high-density polyethylene (PHDPE) framework for auricular reconstruction

However, they increase the risk of alopecia at the incision lines and at the apex of a triangular fap.

An anteriorly based skin fap of minimum thickness is elevated meticulously, and microtic cartilage is excised. Usually, the inferior portion of the fap is attached initially to the lobular remnant. If this is malpositioned, this skin fap may be removed and used as a free graft to improve skin coverage. A TPF fap, based inferiorly, of approximately 10.5 by 13.0 cm is raised off the deep temporal fascia and periosteum beneath, superior to the level of the temporal line. The base of the fap is made wide (around 6 cm) to include additional vascular supply (branches of the occipital artery, postauricular artery, and the mastoid emissary vein), and the base of the fap is made wide, around 6 cm. The fap must be made as robust as possible, and loose areolar tissue on the deep surface of the TPF must be included in it. This tissue, which lies deep to the skin graft, allows the skin to slide over the underlying tissue. This resists surface trauma and implant exposure. The pHDPE framework is then sculpted, fused, and matched to contralateral ear. Prior to implant placement, two fat suction drains are inserted through the skin of the mastoid. One drain lies deep to the pHDPE, while the second lies in the posterior part of the donor site on the scalp. The implant is placed over the mastoid area and covered with the TPF fap after checking its anatomic orientation, projection, and axis. The fap is made to wrap tightly around the implant by the negative pressure generated by the frst drain. The second drain functions to remove any serous exudate from the donor site. The skin fap, which is based anteriorly, is draped over the TPF. It may also be removed and used as a free skin graft. Sometimes, the skin at the ipsilateral mastoid may not be suffcient to cover the surface of the reconstructed ear entirely. In such cases, a full-thickness skin graft may be harvested from the opposing side postauricular region. A graft taken from this region would provide the best color and texture match. To cover the back of the ear, a larger skin graft may be required, which can be harvested from the inguinal region. After activating the drains, the ear may be coated with a layer of antibiotic cream and the concave regions may be dressed with gauze. The entire ear is then covered in a customized cast made of silicone. This cast prevents seroma, hematoma, or shearing trauma, which may compromise the viability of the skin graft. This cast should not be under pressure. A pressure dressing to prevent seromas can be applied over the donor site. All suction drains may be removed following extubation [11].

#### **35.12.2 Complications**

The complications of this procedure may be minor, such as a simple wound infection, or major, such as total fap necrosis with exposure of the Medpor framework beneath. In case the implant is exposed or infected, removal may rarely be required. Late complications include traumatic excoriations to the re-constructed ear, which should be managed with good wound toileting or with local skin faps if required.

#### **35.13 Prosthetic Ear**

Certain traumatic, congenital, or surgical defects may beneft from auricular prostheses. The choice between surgical and prosthetic reconstruction is controversial, particularly for patients. The ideal age for prosthetic treatment is the same as the age for surgical reconstruction, namely, between 6 and 9 years. The child must be capable of caring for the prosthesis. In cases of unsuccessful surgical outcome, the prosthetic ear is one of the options. Prosthetic ear is a suitable option for the ear defects caused by trauma and disease in adult populations.

**Fig. 35.13** Approach for temporoparietal fap. (**a**) Y shape Incision. (**b**) Large Z incision

©Association of Oral and Maxillofacial Surgeons of India

#### **35.13.1 Retention of the Prosthesis**

Tissue adhesives are used conventionally for ear prosthesis retention because of their low cost and quick results. Tissue adhesive is an old method and causes skin reaction. It is diffcult to wear and take off adhesive while bathing and swimming. Osseointegrated implant is superior option for retention, and because of nature sense of prosthesis, ease of use, long lifetime and retention during daily activities, it is accepted by patients. An implant-retained prosthesis is preferred when there is hair on the surface of the defect or when the patient has excessively oily and perspiring skin. The prosthesis may be attached to the implant screws using precision attachments or magnets. Osseointegrated implants are contraindicated during radiation therapy, as the bone is demineralized and prone to hard tissue vasculitis, fbrosis, persistent infections, reduced tissue perfusion, and oxygenation. Osseointegration in such patients is diffcult, but may be attained with hyperbaric oxygen treatment [12].

#### **35.13.2 Prosthetic Technique**

Impressions are made of both the defect and contralateral normal ear. Usually, rubber silicone material is used and plaster models are prepared. The plaster models of contralateral side are used as a reference to sculpt the framework. This is done using wax or clay. Next, a negative mold is obtained when the wax is removed, leaving behind a void. Medicalgrade silicone usually of clear shade is mixed with pigments to create the skin colors of the individual patient. This silicone is packed into the void and cured. After removal from the mold, the texture and the color of the skin can be reproduced to match the contralateral side and adjacent skin [12].

#### **35.14 Future**

Regardless of the method used, ear reconstruction cannot provide an appearance that equals auricular prostheses. Future techniques must focus on emerging tissue engineering technologies that can create bone, cartilage, skin, and blood vessels. This can provide a novel direction for the treatment of patients with microtia. The creation of a natural ear using cultured chondrocytes on a prefabricated cartilaginous framework is an area of active research, but still holds some challenge [1]. Creating functional and durable tissue through tissue engineering can remove the need for donor sites and revolutionize reconstructive surgery.

#### **35.15 Conclusion**

The human ear is a unique structure that is diffcult to replicate owing to its complex cartilaginous structure and thin overlying skin. The ultimate goal of total ear reconstruction should be creation of an auricle that closely matches the normal ear in appearance. Several surgical techniques are available for ear reconstruction. Since microtia is a rare condition, cases are limited, but at the same time, only a high case volume can improve success rates. The learning curve is long and might be at the expense of the patient. Although this learning curve is unavoidable, it is imperative to curtail its steepness. Prior to embarking on ear reconstruction, surgeons must be familiar with the principles and techniques involved. It is important to remember that repetition helps us master the technique.

**Disclosure** Authors have no fnancial conficts to disclose.

#### **35.16 Case Scenarios**

#### **Case 1** (Fig. 35.14a–g)

24 year-old male with Unilateral Left side Grade 3 or Lobule type microtia. On audiometry testing, hearing was normal with conductive hearing on left side. External auditory meatus is absent. He was planned for auricular reconstruction using autologous costal cartilage. Costal cartilage was harvested from ipsilateral side. Synchondrotic junction and foating rib were harvested from the seventh, eighth, and ninth rib. Framework was prepared as shown in photo (b). Tragal component is added in framework. Skin pocket was prepared, and lobule was transposed posteriorly. Framework was inserted in pocket, and suction was applied for close adaptation of skin to framework. Stage II surgery was done after 1 year. Ear was elevated, and cartilage graft was placed for support. Graft was covered with temporoparietal fascia fap and skin grafting done. 6 months postop shows symmetric projection of both ears.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 35.14** (**a**) Preop, (**b**) Framework, (**c**) Postop, (**d**) 3 months postop, (**e**) and (**f**) Comparison between normal and reconstructed ear after elevation of ear, and (**g**) Projection of reconstructed ear

#### **Case 2** (Fig. 35.15a–f)

21 year-old male with Unilateral Left side Grade 4 or Anotia. On audiometry testing, hearing was normal with conductive hearing on left side. He was planned for auricular reconstruction using autologous costal cartilage. Costal cartilage was harvested from ipsilateral side. Synchondrotic junction and foating rib were harvested from seventh, eighth, and ninth rib. Simple Framework was prepared as shown in photo (b). Skin pocket was prepared using Z-plasty incision. Framework was inserted in pocket, and suction was applied for close adaptation of skin to framework. Stage II surgery was done after 1 year. Ear was elevated, and cartilage graft was placed for support. Graft was covered with temporoparietal fascia fap and skin grafting done. 8 months postop shows symmetric projection of both ears.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 35.15** (**a**) Preop, (**b**) Framework, (**c**) Postop, (**d**) 3 months postop, (**e**) and (**f**) Comparison between normal and reconstructed ear after elevation of ear

#### **References**


#### **Additional Reading**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Management of Facial Scars**

Velupillai Ilankovan and Anna Sayan

#### **36.1 Introduction**

When the body sustains injury, the process of wound healing will commence. Scar formation is a part of wound healing. These are described as primary, secondary and tertiary intention processes [1]. In primary, there is close approximation of the wound edges, and in the secondary, the edges could not be approximated. The wound is left open, and the defect is slowly flled with connective tissue. In the tertiary, however, there is infection or contamination and there is a delay until the offending items are removed. This is followed by primary intention healing.

An ideal scar is a thin line or lines in parallel to the relaxed skin tension lines (RSTLs) described by Borges [2]. This should have a natural contour, colour and no distortion of the surrounding structures.

The scar particularly the facial is not aesthetically pleasing and can cause psychological distress to patients, resulting in poor body image, reduced self-esteem, generally loss of confdence and at times certain social stigma.

Prevention of an unsightly scar is primarily important requirement to any Surgeons but particularly important to Facial Plastics and Aesthetic Surgeons.

The origin of the word scar comes from Greek termed "iskharo" and in French "eschori" and interestingly was frst used in the English language in the fourteenth century.

The primary aim in the management of scar is to produce an invisible line.

Less than ideal scars demonstrate features that are highlighted in Box 36.1.

Multiple causes can play a role in unsightly scar formation. Non-clear wound edges cannot give an aesthetically pleasing outcome. Nutritional status, co-morbidities such as diabetes, previously radiotherapy feld and habits such as smoking have a detrimental effect in wound healing and thus

#### **Box 36.1 Characteristics of less than ideal scars**


imperfect scars. The most important factor is also the surgical competence of the operator.

### **36.2 Pathophysiology**

The pathophysiology of wound healing and scar formation is very complicated [3].

The wound healing is characterised by four separate but overlapping phases (Box 36.2).

Haemostasis and infammation occur during the frst 4–6 days. During the frst few minutes after surgery, there are vascular contraction and formation of fbrin clot. The ruptured cell membranes result in the release of infammatory factors in order to cause vasoconstriction, which will last for 5–10 min, and then the vessel dilatation starts. This process can take up to 20 min. The vessel dilatation is caused by histamine, which, in turns, allows infammatory cells to arrive at the wound site. The platelets also adhere to the site of injury. Subsequently, the coagulation cascade will be activated. The structure of the clot will be a fbrin protein network flled with platelets and its contents. The main infammatory mediators released by the platelets are the prostaglandins, leukotrienes, interleukins, growth factors and cytokines. During the infammatory phase, there is also the arrival of neutrophils, macrophages and lymphocytes. The main function of the neutrophils is the removal

V. Ilankovan (\*) · A. Sayan

Oral and Maxillofacial Surgery, Poole Hospital NHS Foundation Trust, Poole, UK

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 747

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_36

#### **Box 36.2 Phases of wound healing**


of the invading materials such as the microbes and products from the cell death. The macrophages are, however, responsible for inducing and clearing dying cells, which will result in improvement of infammation. The apoptotic cells are cleaned by the macrophages, and the reparative stage begins. During this stage, there is migration of the epithelial cells usually after 48 hours and this process continues until the tenth day. Fibroblasts promote collagen synthesis. The epidermis is thickened in layers, and the collagen fbres promote dermal strength. The collagen deposition takes 2–3 weeks, and at this time, the remodelling phase begins. The collagen fbres will become rearranged during this period, and the cross-linked will be aligned along the tension lines. Largely, the maturation phase can take up to a year or longer depending on the type and site of wound. Therefore, the infammatory process plays a major role in scar formation with the resultant fbroblast proliferation migration and differentiation.

The formal scar can be made better by using scar and scar reducing agents such as non-steroidal anti-infammatory drugs (NSAIDs), minocycline and gene therapy. The main recognised scar reducing agents are transforming growth factor (TGF), TGF beta 3, COX-2 inhibitors and angiotensin receptor blockers [4]. The TGF beta modulating agents are still undergoing phase 2 trials in order to fnd out ideal scar modulating topical or intralesional agents.

Microfat grafting [5] is a technique with great potential in scar management where fat can be used intralesionally using a small 0.7 mm diameter cannula. It has been shown to be even more effective in placing fat in deep dermal layer of the skin using a 23-gauge needle in a treatment called sharp needle intradermal fat (SNIF) grafting. However, the work carried out by Tonnard et al. [6] in emulsifying the fat fltered until a liquid suspension was obtained, called Nanofat, which is injected using a 27-gauge needle, which conveys excellent outcome.

The ideal scar is an invisible line. There was increased interest in the recent past on intrauterine surgery to improve craniofacial clefts with some success and large failures. The extrauterine scars can present as stretched to depressed, hypertrophic or at times keloid. The stretched and depressed scars are as a result of inadequate primary intention management. The differences between a hypertrophic scar and keloid scar are highlighted in Box 36.3.

#### **Box 36.3 Hypertrophic scar vs Keloid**


#### **36.3 Scar Management**

#### **36.3.1 General Principles**

Scar management includes prevention, pre-injury treatments during the healing period and defnitive treatment once the scar is established.

It is essential to take accurate history about any previous scar formation. If it is known, extra precautions should be taken, patients should be alerted and incisions along the susceptible sites should be omitted.

For example, when doing blepharoplasty with a history of previous hypertrophic scar, we should avoid a subciliary incision and the treatment should be carried out via a transconjunctival approach. Avoidance of treatment should be practised, for example, a patient who had keloid on previous ear-piercing episodes.

Limiting skin stretching during wound healing, facilitating appropriate wound resting and preventive exercises in certain sites such as chest and suprapubic areas are observed. Atkinson et al. [7] reported a randomised control trial of the effect of tape fxation and the prevention of hypertrophic scars post-caesarean section with signifcant scar reduction.

Therefore, scar reduction therapies are classifed into:


The latest progress in scar management includes treatment with lasers to reduce angiogenesis, subcision and intradermal fllers. The emulsifed fat (NanoFat) with stromal vascular fraction (SVF) and plasma rich protein (PRP) usage is the current trend in the non-surgical outcome of scar management.

#### **Box 36.4 Non-surgical remedies**


#### **36.3.2 Non-surgical Remedies**

The non-surgical modalities of scar management are highlighted in Box 36.4, and the description of each is as follows:

#### • *Steroid*

Triamcinolone is the mostly used steroid for scars. The mode of action when used as an intralesional therapy is in inhibition of the infammatory mediators, inhibition of fbroblast proliferation, collagen synthesis and inhibition of TGF—BETA 1 and BETA 2—and enhancement of collagen degradation and collagenase action in keratinocytes [8].

The published reports, however, give varying outcomes with dose-dependent side effects such as hypopigmentation, telangiectasia and dermal atrophy [9]. There is an encouraging outcome, however, in combination therapy when the dosage is reduced.

The suggested mode of action is an inhibition of fbroblast proliferation and TGF-BETA 1-induced collagen synthesis [10]. Anecdotal results are positive; however, trials lack adequate controls. Nonetheless, the effect is encouraging in combination therapy with steroid and pulse dye lasers. Much work is required in controlled studies.

#### • *Bleomycin*

It is an antibiotic and has been used intralesionally in vascular malformation with good outcome [11].

The mode of action is in reduction of collagen synthesis and increased destruction of collagen by inhibiting Lysyl Oxidase such as TGF-B1 [12]. Much work is needed in its defnitive usage.

• *Lasers*

Lasers target three chromophores such as water, melanin and haemoglobin. Laser-induced tissue hypoxia results in the breakdown of disulphide bonds of the collagen fbrils. Pulse Dye Laser (PDL), KTP laser and Nd YAG lasers have affnity to haemoglobin, leading to collagen necrosis, and results in reduction of proliferation of fbroblast and deposition of collagen type 3. Ablative lasers remove the scar layer by layer with minimal thermal injury [13].

• *Dermabrasion*

This technique is still used in treating irregular scars such as ice pick scars of acne. The aim is to abrade up to the reticular dermis, allowing epithelialisation to take place. This treatment causes erythema for a long time, and the symmetrical outcome is not guaranteed.

Microdermabrasion is an advancement where there is high-speed pressurised aspiration-compression system. The beneft is that it minimises deep thermal injury [14].

Carbon Dioxide (CO2) and Erbium laser resurfacing supersedes microdermabrasion with minimal thermal damage. Laser resurfacing acts in a different way compared to the vascular lasers. The vascular laser action is as a nonablative principle, whereas CO2 and Erbium cause ablation.

Vascular lasers decrease the prominence by destroying the blood vessels and stimulating collagen remodelling, thus softening the scar, whereas the ablative lasers such as CO2 and Erbium ablate or vaporise the excessive tissues. CO2 can induce more collagen remodellation and promote wound contraction [15].

The vascular lasers are used in hypertrophic and keloid scars. CO2 and Erbium are useful in stretched, asymmetric and irregular scars. There is a restriction as it is not effective in all skin types as resurfacing can result in excessive pigmentation in dark, Asian and African skins.

#### • *Subcision*

It is a technique where depressed scars are elevated, and the controlled trauma can aid in formation of new connective

<sup>•</sup> *5FU*

tissue. This is carried out by custom-made subcision knives or 20 gauge needles. It can be combined with autologous fat injection to the subcised areas flling in the space and simultaneous laser resurfacing [16].

#### • *Fillers*

Synthetic Hyaluronic acid, calcium hydroxylapatite and bovine collagen are used in aesthetic surgery for voluminisation. They can be used in treating depressed scars. However, these agents cannot be used in a larger quantity as they will cause subcutaneous nodules and infammation, and in bovine collagen, there is 3% incidence of allergic history. There is also a need for repeat injection. Autologous fat has taken over as a material of choice for flling in scar management.

#### • *Silicone gel sheets*

These sheets are used prophylactically in known patients for bad scars as well as therapeutically. However, the outcome for hypertrophic scars is still questionable and inconclusive.

It appears that controlled studies have shown signifcant benefcial outcome in scar volume when the silicone sheets are used or not used in mirror image wounds. A Cochrane review of 13 trials involving 559 patients, however, concludes weak evidence in preventing hypertrophic scars in susceptible patients [17].

The mechanism of action is in producing hydration to the scars by occlusion.

#### • *Pressure therapy*

It is a perceived therapy that there is positive evidence in the literature. The largest randomised trial showed no signifcant difference in scar reduction with pressure therapy when compared to the controlled group [18].

#### • *Cryotherapy*

A large uncontrolled study of 135 patients with 166 keloids demonstrated 79.5% response rate with 80% reduction in scar volume. However, the results are not reproducible. This treatment causes atrophic, depressed scars with residual hypopigmentation [19].

Therefore, the usage of cryotherapy particularly on the face should be discouraged as a modality.

• *Radiation*

It is an effective adjuvant to surgical excision particularly to keloid. The effect is caused by inhibition of proliferation

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 36.1** (**a**) Keloid Scar right ear lobule. (**b**) Postoperative photograph following scar excision and one dose of radiotherapy

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 36.2** (**a**) Keloid Scar post-auricular region. (**b**) Post-operative photograph following scar excision and one dose of radiotherapy

of fbroblasts and neo-vascular blood formation, resulting in decreased collagen production [20].

The highest cure rate is described in a single dose within 24 hours after surgical excision; however, further studies are needed to evaluate the dosage and to obtain optimum results (Figs. 36.1 and 36.2).

#### • *Emulsifed fat for scar rejuvenation*

The fat tissue is accepted not only as a simple layer of insulation and as a storage for energy but also as a complex endocrine organ, which is intrinsically involved in metabolism and immunomodulatory activities and can provide multi-source resources for stem cells and other undifferentiated cell population, which is essential for regeneration.

In addition to the adipocytes in the fat tissue, there are other cell groups that are functionally very important such as stromal vascular fraction (SVF) and cell-assisted lipotransfer (CAL). The SVF of adipose tissue is a rich source of epithelial progenitor cells, T cells, B cells and adipose tissue macrophages [21]. Separation of SVF is a time-consuming and expensive process requiring collagenase treatment and centrifugation. The recent clinical results obtained with Nanofat grafting where the cells are emulsifed show greater value than the components of SVF used separately.

In Nanografting, a 23 gauge needle is used as a sharp needle for subdermal fat injection technique (SNIF) followed by a 27 gauge needle to superfcial layers. In order to do this, the fat should be emulsifed and takes the name, thus, Nanofat [6].

This now emerges to the forefront in regenerative medicine due to its ability to differentiate into a variety of different cells of cell lineage and the anti-apoptotic, antiinfammatory, pro-angiogenic immunomodulators and antiscarring properties.

Nanofat has shown to improve the aesthetics of hypertrophic and keloid scars by improving the texture of the scars in addition to improving the symptoms of pain and itching [22].

Fat is used in voluminisation initially as foundation micrograft just above the periosteum. The second layer is subdermal graft followed by subcision and lastly Nanofat injection using SNIF technique with 23-gauge needle followed by superfcial needle injection using 27-gauge needle. This process is to treat depressed scars. Intralesional Nanofat injection improves hypertrophic and keloid scars. This can be combined with other modalities such as laser resurfacing.

#### **36.4 Surgical Scar Management**

#### **36.4.1 Basic Principles**

As described above, an ideal scar should be an imperceptible line parallel to RSTL. The only exception is scar along the lower lid due to the possibility of ectropion, if incisions are made in parallel to RSTL.

The aim of scar revision is to re-orientate the scar to follow the RSTLs and correction of adjacent structure distortion.

Patient understanding, nutrition, expectation and the psychological stability are paramount factors to implement preoperatively prior to any scar revision exercises particularly in burn scars. The timing of the revision is also important as the remodelling may take up to 12 months.

Nutritional status and the medical history are important pre-operative considerations. It has been described with certain evidence that the use of vitamins A, C and E and zinc have benefcial effects and, at the same time, some herbal supplements such as arnica, garlic, ginseng and saw palmetto can impair wound healing [22]. Systemic conditions such as diabetes and immunosuppression can adversely affect wound healing. Smoking has proven to cause perilous effect on healing and wound repair.

Vitamin E refers to a group of ten lipid soluble compounds that include both Tocotrienols and Tocopherols as a fat soluble antioxidant; it stops the production of reactive oxygen species formed when fat undergoes oxidation [23]. It has been identifed that alpha-tocopherol, the most biologically active form of vitamin E, has anti-infammatory effects by decreasing plasma C-reactive protein (CRP) levels and release of pro-infammatory cytokines. The CRP, a downstream marker of infammation in addition to being a risk marker for cardiovascular disease, could contribute to atherosclerosis. Alpha-Tocopherol has been shown to decrease CRP level in patients and has a positive effect in scar reduction. Topical vitamin E application has been practised in managing scar 10 days post-suture removal. Anecdotally, in the last 25 years, good scar outcome has been observed.

#### **36.4.2 Surgical Technique**

In most circumstances, incisions should be made parallel to the skin surface. A number 11 or 15 blade is ideal. Tissue handling must be atraumatic. The skin faps should be held with non-toothed forceps, and the tooth forceps should only be used to handle tissues subdermally. Undermining and constant hydration of edges are essential. In stretched scars, preservation of the dermis by de-epithelialisation will provide extra support in correcting the depression. Haemostasis should be achieved using a bipolar diathermy again minimising thermal injury to the surrounding areas.

Suturing is done in layers. In areas where supportive tension is required, resorbable round body needle sutures are useful. Depending on the site and the extent of the scar, short- or long-term resorbable sutures could be selected. With deep suturing as much as possible, the knot should be buried with skin approximation to achieve 'eversion'. Simple-interrupted sutures are preferable in a majority of areas; however, subcutaneous running sutures could be used where only gentle approximation is needed.

#### 1. *Z plasty* (Fig. 36.3)

This is a common technique used in scar revision to either change the direction of the scar or lengthen the scar. Contracted scars can be corrected by plating multiple simultaneous Z plasties.

The Z plasty is created by using the original scar as a central portion, and triangular faps are raised. Multiple variations are in Z plasty. In the classical Z plasty, all the limbs are of equal length and the angle between the faps is 60°. The scar will lengthen by 75%. A 30° angle will lengthen by 25%, and 45° will lengthen by 50%. Multiple Z plasties are useful in long scars, which can be divided into separate segments, and the angles are contoured or modifed depending on the sites.

#### 2. *W plasty* (Fig. 36.4)

This technique is used to irregularise scars so that dimensions of the scar are not perceived by the naked eye. A series of consecutive triangles are made. It is mirror image on the opposite side. The arm length should be around 5 mm, and the angle in-between the fap should be maximum 90°. One side of the triangle should be in parallel to our RSTL. The

**a b c**

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 36.4** W plasty— (**a**) scar revision. (**b**) post-operative

**Fig. 36.5** V-Y scar

lengthening correction. (**a**) V incision. (**b**) Triangular faps raised. (**c**) Y closure

triangle are excised, undermined and closed with interdigitation. This technique is very useful in correcting unsightly hairline scars such as revision of face lift.

#### 3. *Geometric broken line closure (GBLC)*

This is another technique to minimise the perception of a long scar. Here, random geometric designs are planned with corresponding mirror images. The length of the limbs should be 3–6 mm and at the angle near to 90°, and a W plasty could be done at the end of the design.

#### 4. *V-Y and Y-V advancement*

V-Y scar correction (Fig. 36.5a–c) is utilised when there is an indication on scar lengthening in contracted scars with 'trap door deformity'. In contrast, Y-V technique is utilised where the scar is shortened, removing the 'Y 'extension (Fig. 36.6a–c).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 36.6** Y-V scar shortening correction. (**a**) Y incision. (**b**) Triangular faps raised. (**c**) V closure

©Association of Oral and Maxillofacial Surgeons of India

Flaps can be used to revise large scars. "Doggy ear" and "trap door deformities"could be improved by excising the excess. For passive scar settlement, selective bulking and simultaneous multiple 'Z' and 'W' plasties are useful adjuncts.

#### **Clinical tip**

When repairing wounds in patients who are prone to develop hypertrophic scars, deep sutures should be placed using round bodied needles. The suture removal is delayed by an extra 3–4 days. Applying steri strips after removal of the sutures adds extra support, and this should be incorporated to achieve the best result.

Prophylactic intralesional steroids in patients prone to hypertrophic scars should be considered. Obliteration of the dead space by appropriate sutures or pressure dressings with or without drains should be considered to prevent haematoma formation. If not, haematoma on its own will spoil the good work of scar revision.

#### **36.5 Future**

Extrauterine scarless surgery is not possible. Therefore, careful patient factor and scar characteristics should be studied to prevent unsightly scar formation and to correct perceptible scars.

General health and optimising comorbidities are important requirements to achieve good scars. Both non-surgical and surgical options should be available in the armamentarium to the Surgeon.

Nanofat has very positive potential in scar management. The research on gene therapy using adenovirus as a mediator to deliver dermal fbroblast is encouraging [24].

**Fig. 36.7** Algorithm for scar management

Although infammatory response is traditionally believed to be a key event for wound healing in adult skin, studies of foetal wound healing suggest that a high level of infammation might prevent good scar formation rather than enhancing the wound healing process. Therefore, further studies are needed to confrm if really infammation is necessary for wound healing in adult skin. However, at present, we need to follow the infammatory process and available evidence of therapeutic modulators of scar formation.

Furthermore, it is paramount to consider that there are clinical, histological, biochemical and molecular differences between hypertrophic and keloid scars. There is marked difference in the proliferative and apoptotic cell deaths between the scars, resulting in variable response of different treatments. This should be taken into account in treatment planning process.

It is also essential to avoid excessive movements that can stretch the wound and for avoidance of the scar to direct mechanical forces such as friction and scratching and particularly earlobe wounds, to minimise the contact with pillows and wound hygiene.

Not least the patient's involvement plays a vital role in the management of scars. Variable scales in the literature exist for reliable and reproducible scar management, for both the observer, i.e. surgeon, and the patient. The observer opinion is always infuenced by vascularisation, thickness and pigmentation. The patient opinion, on the other hand, is infuenced by action of itching sensation and thickness of the scar. Out of the available assessment scales, the patient and observer scar management described by Draaigers L et al. is an informative tool in documentation of the progress in the management of scar, which should be addressed [25].

In summary, a surgeon should have an algorithm to follow on how to manage scars in normal patients as well as patients who are prone for hypertrophic and keloid scars (Fig. 36.7).

#### **36.6 Conclusion**

Scar formation is a part of wound healing process. Facial scars can be aesthetically detrimental and affect social stigma. As facial surgeons, we need to achieve ideal scars with natural contour, colour and limited distortion. It is paramount to remember that scar management includes prevention, treatments during the healing period and defnitive management once the scar has been established. We have, in this chapter, included all the different available treatments separating them into non-surgical remedies and surgical techniques. The algorithm, in this chapter, allows a very easy review process for surgeons who manage stretched, **Fig. 36.8** (**a**) Pre-operative. (**b**) Post-"microfat grafting" and laser resurfacing

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depressed, hypertrophic and keloid scars.DisclosureAuthors have no fnancial conficts to disclose.

#### **36.7 Case Scenarios**

#### **Case Scenario 1** (Fig. 36.1)

A 27-year-old female patient of Asian ethnicity had an extra ear piercing to the right earlobe. Within 4 months, she started to develop a very painful hard lump at the pierced site. Within the following 6 weeks, it developed into an irregular mass involving the whole of the earlobe.

Her medical history was unremarkable, and she was not on any medication.

On examination (Fig. 36.1a), there was an unsightly thick lumpy scar along the right earlobe. A diagnosis of keloid was made.

Under a local anaesthetic, the keloid scar was excised and the earlobe was reconstructed. The next post-operative day she underwent single dose of radiotherapy (10 Gy) as an outpatient.

On review, 6 months post-treatment (Fig. 36.1b), she had no recurrence and on palpation, the skin was soft and non-tender.

#### **Case Scenario 2** (Fig. 36.8)

A 48-year-old Caucasian patient who had a considerable amount of sun exposure presented with an unhappy peri-oral aesthetics (Fig. 36.8a).

Her medical history was unremarkable, and she was not on any medication.

In one examination, she had loss of volume along the peri-oral site mainly along the upper lip. The vermillion border had lost its defnition. She had multiple small vertical subdermal lines, which were crossing the vermillion border. She also had epidermal thinning.

A diagnosis of aging of the peri-oral area, particularly upper lip, was made. She, in fact, had epidermal thinning, subdermal scaring and loss of inter- and intramuscular fat.

She underwent "microfat" grafting to restore the volume, subdermal "emulsifed fat" to restore the subdermal structure and an "erbium laser resurfacing" (fuence 500 mJ, mode: SP, spot 3 mm, frequency 20 Hz).

The post-operative appearance 4 months later (Fig. 36.8b) showed excellent volume restoration, much improvement in the subdermal scaring, better vermillion defnition and a new regenerative skin.

This combination technique is very useful in burn scar management.

#### **References**


16. Orientreich DS, Orientreich N. Subcutaneous incisionless (subcision)surgery for the correction of depressed scars and wrinkles. Dermatol Surg. 1995;21:543–9.

2002;28:714–9.


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**37**

## **Surgical Facelift**

Velupillai Ilankovan and Tian Ee Seah

#### **37.1 Introduction**

An ancient Chinese proverb "岁月不饶人" observed that "no one is spared from the ravages of ageing". A combination of age, gravity, physiologic contraction of facial muscles and solar (sun) and chemical (smoking) insults results in intrinsic and extrinsic changes to the skeleton, muscles and skin [1]. Preservation of one's youthful looks has been a goal of humans regardless of cultures and ethnicities. The search for this elixir of youth was found unexpectedly in the hands of cosmetic surgeons. Even with the recent advent of skin peels, botulinum toxin injections, lasers and injectable fller injections, the century-old facelift still possesses the most dramatic improvement to the moderate to severe ageing lower face when done well.

Facelift or rhytidectomy as its name suggests is a procedure to partially eliminate folds, creases and wrinkles (rhytids) caused by gravity and degeneration. In effect, the creation of two large cervicofacial faps, which, after suspension and trimming, produces an overall tightening of the skin and the fascial envelope of the face and neck, results in restored anatomical structure. Facelift can help to negate some of these gravitational problems and produce some intrinsic improvement.

### **37.2 Historical Perspective**

Historically, rhytidectomy was limited to skin elliptical excisions and tightening. The German surgeon, Eugen Höllander, frst described being persuaded by his patient to remove excessive skin in the temporal, preauricular and postauricular regions in 1901. With cosmetic surgery frowned upon in

V. Ilankovan (\*)

T. E. Seah TES Clinic for Face and Jaw, Singapore, Singapore those times, he did not report his surgery immediately but only recounted retrospectively that the iatrogenic wounds when approximated resulted in some tightening in 1912 [2]. The initial reports of rhytidectomy were dominated by a slew of American surgeons such as Cantrell (1902), Miller (1907) and German surgeons, Lexer (1906) and Joseph (1912) [3]. The French surgeon Passot wrote an important paper "La chirugie esthétique des rides du visage" in 1919 where he illustrated strategically placed forehead, malar, cheek and submental elliptical incisions to tighten the face for aesthetic purposes, thus heralding the concept of short scar rhytidectomy (Fig. 37.1).

©Association of Oral and Maxillofacial Surgeons of India

Oral and Maxillofacial Surgery, Poole Hospital NHS Foundation Trust, Poole, UK

**Fig. 37.1** Illustration showing Passot's principles on facelift through elliptical excisions

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_37

However, with limited undermining, wounds were closed under tension, resulting in unsightly scarring. To circumvent this problem, skin fap only procedures during which only the skin was raised, undermined for a short distance and tightened were introduced (Bames 1927) [4].

The results of skin fap only facelift were short term with limited correction of the ageing face, forcing surgeons to search for better alternatives. In 1974, Tord Skoog, a Swedish surgeon, revolutionized facelift concepts by describing the dissection, elevation and tightening of the superfcial fascia of the face in addition to removing excess skin. He expounded the importance of retro-positioning the "buccal fascia" and the platysma for better results. The importance of this technique was later cemented when the superfcial fascia of the face was clarifed as the "superfcial muscular aponeurotic system" (SMAS) by Mitz and Peyronie in a landmark paper in 1976 [5]. Manipulation of the SMAS layer in a superior or superolateral vector became an important part of modern facelift. Soon, a furry of papers on the modifcations to facelift procedures concentrated on the management of the SMAS.

Treatment of the SMAS layer could be broadly categorized into three methods. They were plication, elevation, imbrication and SMASectomy [6]. The most conservative of these methods was plication of the SMAS layer, as it did not actually involve dissecting the SMAS layer but instead used sutures to fold the SMAS and achieve a tightening effect [7]. More aggressive management of the SMAS included imbrication, which involved the elevation and repositioning of the SMAS in a superior or superolateral vector [8]. In standard SMAS elevation, the SMAS was dissected, lifted off the parotid fascia and secured to the underlying zygomatic soft tissues or the deep temporal fascia (Fig. 37.2).

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©Association of Oral and Maxillofacial Surgeons of India

**Fig. 37.3** SMASectomy. 1–2 cm of the SMAS is excised superfcial to the anterior border of the parotid

SMASectomy was later described [9]. This required excision of approximately 1–2 cm strip of the SMAS, superfcial to the underlying parotid fascia, and then tightening were carried out by suturing the opposing two cut SMAS margins [6] (Fig. 37.3).

It soon became obvious to the surgeons that skin excision and SMAS manipulation were only effective in treating the lower face but not as effective in treating midface ageing. In particular, the nasolabial fold proved to be a stubborn adversary. The spotlight turned towards the high density, retaining ligaments such as the zygomatic retaining ligaments, which prevent effective rejuvenation of the midface using the aforementioned procedures.

The deep plane facelift was described by Hamra to include the malar fat pad [10]. In this, the dissection and elevation of the SMAS layer were carried out further to release the zygomatic retaining ligaments so that more traction could be obtained from the midface. The orbicularis oculi and later septal reset were included to improve midface aesthetics, and the term composite facelift was coined by Hamra [11].

As the facelift landscape progressed, efforts turned almost full circle towards smaller incisions. Comparisons of different published facelifts were unable to reveal an optimal technique [12] although complications were signifcant higher in extensive SMAS procedures.

Attention turned towards having minimal excision, limited dissection and SMASectomy with imbrication, and in 2001, Saylon and later Fulton et al. described the S-lift [13]. In this technique, the preauricular skin was excised in a predetermined S-shape followed by purse-string plication of the mobile SMAS using a U-shaped purse string suture and an O-shaped purse string suture. Both sutures were anchored into the periosteum of the zygoma.

Tonard et al. later introduced the minimal access cranial suspension (MACS) as a modifcation to the S-lift [14] (Fig. 37.4).

In this procedure, he described suspending the sagging SMAS tissues with cranially directed purse string sutures via limited incisions that extend from the sideburn to the inferior helical attachment. Four main differences lie between the "S" lift and the 'MACS' lift. First, the S-Lift pre-empted the amount of excess skin and excised it via an S-shaped incision. The MAC lift redraped the excessive skin and removed it according to the margin. The second difference lies between point of anchorage as the 'S-lift' anchored to the periosteum of the zygoma, while the 'MACS lift' anchors to the superfcial layer of the deep temporal fascia. Third, during the S-lift, SMASectomy and imbrication were carried out, while during the MACS lift, only plication was performed. Fourth, besides the two O and U-shaped sutures, the MACS lift utilizes a third vertical suspension suture that suspended the malar fat pad, thus reducing the depth of the nasolabial fold. This area is accessed by extending the temporal hairline incision, and Tonard and Verpaele called this the extended MACS lift.

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#### **37.3 Anatomy of Ageing Face**

Some of the gravitational changes include lateral brow ptosis, tear trough, malar palpebral groove, SOOF descent, malar fat descent, deepening of the nasolabial groove, buccal fat pad herniation, marionette lines, jowls, loss of neck defnition, submental fat and excess skin [1].

With ageing, a combination of gravitational forces, laxity of the skin due to loss of elasticity, decreased dermal thickness and loss of dermal appendages results in ptotic, hanging skin.

The mid cheek's fat is divided into three compartments [15] (Fig. 37.5). It is thinnest at the lid-cheek segment and is thickest in the nasolabial region. The malar fat is also moderately thick although not as thick as the nasolabial region.

Accumulation of fat in the cervical region results in loss of neck defnition and submental fat.

Superfcial fat and deep fat are separated by SMAS layer. The superfcial fat is separated into fve compartments, namely, the nasolabial, medial cheek, middle cheek,

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 37.5** Cheek fat is divided into three compartments. They are lidcheek segment (Orange), Malar segment (red) and nasolabial region (yellow). (Figure adapted and redrawn from Aesthetic Plastic Surgery 2009, Chapter 6 by Mendelson BC)

**Fig. 37.4** MACS Lift

lateral temporoparietal and inferior orbital fat. Deep fat is divided into the deep medial fat and suborbicularis oculi fat (SOOF) [16].

The superfcial musculoaponeurotic system (SMAS) is a fbrous sheath, which was described in a classical paper by Mitz and Peyronie [5] in 1976, and starts from the galea superiorly. Superolaterally, it is continuous with the superfcial temporal fascia also known as the temporoparietal fascia. In the central upper face, deep into the superfcial fat, the SMAS layer is invested by the muscles of facial expression, derived from the embryonic second branchial arch: frontalis, orbicularis oculi, corrugator supercilii, depressor supercilii and the procerus. In the middle third, the SMAS is invested by the nasalis muscles, zygomaticus major, minor, levator labii superioris alaeque nasi and levator labii superioris. Laterally, the SMAS is superfcial to the parotid fascia and extends inferiorly to include the platysma muscles. Inferomedial, the SMAS is invested by the orbicularis oris, risorius, depressor anguli oris, depressor labii inferioris and mentalis and is continuous with the platysma.

With the exception of the levator anguli oris and mentalis, the facial nerve travels deep into the SMAS layer and innervates the muscles of facial expression, making dissection above the SMAS during facelift safe [16].

An analogy of the retaining ligaments is that they are rooted in a tree into the periosteum and deep fascial thickening, and as it approaches the SMAS, it divides into numerous branches and inserts into the dermis called retinacular cutis [15] (Fig. 37.6).

Stuzin [17] and Furnas et al. [18] described the retaining ligaments [17]. The partitioning of separate fascial spaces and compartments is caused by these retaining ligaments, which are classifed into osteocutaneous and fasciocutaneous retaining ligaments.

Osteocutaneous retaining ligaments originate from the periosteum and include the zygomatic and mandibular cutaneous ligaments. Stout zygomatic retaining ligaments originate from the inferior border of the zygomatic arch towards the junction between the arch and the body and insert into the dermis of the skin as fbrous septa. It is posterior to the zygomaticus major muscle, approximately 3 mm in width, 0.5 mm in thickness and 4.5 cm anterior to the tragus [18]. Loss of support results in malar fat descent.

The mandibular ligament originates from the periosteum 10 mm above the mandibular border, extends along the anterior one third of the mandibular body and inserts into the dermis [19] (Fig. 37.7). It coincides with the anterior margin of the jowl.

Fasciocutaneous retaining ligaments include the masseteric and parotid cutaneous ligaments also known as the platysma auricular ligament and coalesce between the superfcial and deep fascia of the face [1].

Masseteric ligaments originate from the parotidomasseteric cutaneous ligaments, and. loss of support results in

V. Ilankovan and T. E. Seah

**Fig. 37.6** Retaining ligaments (RLs) insert into the subcutaneous layer as retinacular cutis. It is likened to a tree by Mendelson BC [15]. (Figure adapted and redrawn from Aesthetic Plastic Surgery 2009, Chapter 6 by Mendelson BC)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 37.7** Osteocutaneous ligaments comprising the zygomatic retaining ligaments (ZRLs) and the mandibular retaining ligaments (MRLs)

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**Fig. 37.8** Fasciocutaneous retaining ligaments comprising the masseteric retaining ligaments (MasRLs) and the parotid cutaneous ligaments also known as platysma auricular retaining ligaments (PARLs)

facial jowling. Parotid cutaneous ligaments are formed by the posterior border of the platysma, which had receded into fascial condensation. It is fused with the parotid fascia, is attached to the overlying skin and provides frm anchorage between the platysma and the dermis in the inferior auricular region (Fig. 37.8).

#### **37.4 Standard Facelift**

Surgery can be carried out either under general anaesthesia or under local anaesthetic with or without sedation.

Local anaesthesia comprising Lidocaine 2% with adrenaline 1:80,000 is infltrated in the zygomaticofacial region, infraorbital, mental, greater auricular (Fig. 37.9) and the lesser occipital nerves.

Tumescent solution reconstituted with 1 L of saline, 50 mL of 1% lidocaine, 1 mL of adrenaline 1:1000 and 6 mL of 8.4% Sodium Bicarbonate is then injected subcutaneously after stab incisions are placed in the temporal, preauricular, postauricular and submental regions. Approximately 300 mL of tumescent solution in all is injected.

In both approaches, infltration of Tumescent solution in a subcutaneous plane is essential to carry out atraumatic dissection. In our practice, 95% of standard facelift are carried out with simultaneous neck lift, as we feel it would be impossible to mobilize the attenuated soft tissue to achieve symmetry and an unoperated look of the midface without bringing attention to the neck aesthetics.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 37.9** Greater auricular nerve block

#### **37.4.1 Incision**

The incision lines are divided into four sections: temporal, preauricular, postauricular and scalp extension. The temporal component is either into the hairline or just at the hairline/ sideburn border. The latter has the advantage of not moving the sideburn position; however, it would give a telltale sign of a visible scar. In the former approach, the sideburn area may get lifted into the temporal area and the scar will be hidden. This position should be made in conjunction with discussion with the patient, and suitability of the incision should be selected.

The preauricular marking could be a pre-tragal, intratragal or post-tragal. The latter can distort the tragal projection, and the pre-tragal will give a visible scar. We prefer an intra-tragal approach and obtain the tragal projection by placing a subcutaneous anchor suture before the fnal closure in order to maintain the natural concavity and simultaneously achieve an invisible scar (Figs. 37.10 and 37.11).

The postauricular incision should be a few millimetres into the postauricular area from the sulcus so that postoperatively the scar will settle down comfortably into the sulcus. The scalp extension is carried out by multiple W or Z plasty type incisions in a trichophytic fashion to minimize hair loss and to have an invisible scar (Fig. 37.12).

A 2.5 cm curvilinear incision parallel to the mandibular contour is the submental incision to the neck lift section in order to expose the anterior border of the platysma and the platysmal dissection.

#### **37.4.2 Dissection**

The submental fap dissection is carried out at frst to expose the platysma muscle as much as possible (Fig. 37.13).

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**Fig. 37.10** Temporal to preauricular incision (red). Occipital or scalp extension (broken line)

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**Fig. 37.12** Illustration showing the postauricular and occipital or scalp extension

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**Fig. 37.11** Hairline to tragal incision (red). Occipital or scalp extension (broken line)

Next, the scalp and postauricular dissection is carried out. The anterior border of the sternocleidomastoid muscle and posterior border of the platysma are exposed, and a cavity of the neck is connected anteriorly and posteriorly (Fig. 37.14). The next step is to focus on the temporal and preauricular dissection. In the temporal, the deep part of deep temporal

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**Fig. 37.13** Dissection is in the supraplatysma plane

fascia is exposed, which we use as an anchor point to the SMAS suturing (Fig. 37.15). The preauricular dissection will expose the zygomatic ligaments, lateral end of the orbicularis oculi and the anterior border of the parotid–masseteric fascia with careful attention towards the buccal branch of the facial nerve (Fig. 37.16).

The preauricular, neck and postauricular dissection should now be in one cavity.

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**Fig. 37.14** The postauricular fap is then connected to the cervical fap and the submental region made previously

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**Fig. 37.15** Deep layer of the deep temporal fascia exposed

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**Fig. 37.16** After the deep temporal fascia is exposed, dissection is carried out in a different plane subcutaneously to raise a skin fap

#### **37.4.3 SMAS and Platysmal Elevation and Plication**

SMAS elevation and management are carried out in various forms. We elevate the SMAS in an inverted L fashion (Fig. 37.17) starting at the preauricular plane, and the superior limit is at the lateral end of the zygomatic arch. The anterior dissection passes to the parotid-masseteric fascia (Fig. 37.18). The inferior dissection is to join the subplatys-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 37.17** An inverted L shape incision (blue lines) is made on the SMAS stopping short of the parotid fascia. The shorter limb is just below the zygomatic arch, while the longer limb is in the preauricular region

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 37.18** Cut SMAS peeled anteriorly to show underlying parotid. Facial nerve exits the parotid deep into the SMAS. Deep into these are the masseter muscles followed by the buccinator muscles with horizontal muscle striations

mal plane at the angle of the jaw with consideration to avoid damage to the two or three cervical branches. In our practice, the elevated SMAS is anchored in a superior direction to the deep part of the deep temporal fascia (Fig. 37.19).

Our platysma dissection and plication are in four steps. The anterior border of the platysma is sutured in the midline [20] (Fig. 37.20). In some patients with short neck, the platysmal suturing needs to be hitched to the body of the hyloid bone. In some patients, a release of the inferior border of the platysma muscle at this area could also be considered. Then,

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 37.19** The cut SMAS is then advanced superiorly and sutured to the deep temporal fascia with 3/0 Polygluconate (Maxon, Tyco Health UK Ltd., Gosport PO130AS, UK) (blue line)

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**Fig. 37.20** The medial edges of the platysma are sutured to each other at the midline in a corset manner

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**Fig. 37.21** A submental incision is made (white outline). Corset sutures are done twice, and the suture is plicated to the mastoid fascia on both sides

the lateral border of the platysma muscle is sutured to the anterior border of the sternocleidomastoid muscle. The third step is in platysmal plication is placing a cinch suture, which is placed joining the two anterior borders of the muscles in the midline and, after catching the platysma muscle in two or three areas, hitched the sternocleidomastoid muscle and the fnal anchor into the mastoid periosteum (Fig. 37.21). Depending on the neck anatomy, we sometimes place a second cinch suture about 5–6 mm below the frst to avoid bulging of the submandibular gland.

#### **37.4.4 Closure**

Meticulous haemostasis is done with bipolar electrocautery throughout the procedure. The cervicofacial faps are draped over the margins in a superolateral vector with much emphasis on the superior than the lateral direction (Fig. 37.22). Final anchoring is done with two key sutures that are placed along the helical attachment and the superior aspect of the postauricular incision. Cuts are made on the excess skin, perpendicular to the fap margin, stopping just short of it (Fig. 37.23). This allows the margins to be visualized when trimming the excess skin. If a tragal incision was made, the skin can be thinned and trimmed to mimic tragal shape and skin during closure at the tragus. Dog ears are preferably removed at the apex rather than in the ear lobe region. The ear lobe is then replaced 15° posterior to the vertical position to reduce the telltale signs of facelift procedures. Layered repaired is then carried out in the fnal closure.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 37.22** Excess skin is draped in a superolateral vector over the margins and excised

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**Fig. 37.23** Cuts are made perpendicular to the fap margin stopping short of the margins and then excised accordingly

#### **37.4.5 Support Dressings**

There are different ways of providing this fnal exercise. We apply antibiotic topical ointment followed by non-sticky dressing to the pre- and postauricular area and an adjustable Velcro band. In the literature, however, various pressure dressings are applied.

#### **37.5 Post-operative Management**

Velcro bands are removed on a daily fashion. Wounds are cleaned followed by topical ointment and reapplication of the Velcro band.

The medications are taken on a prescribed fashion.

The patient is placed on antibiotics and painkillers for a week. Sleeping is done with the head elevated by 2–3 pillows. The patient is seen on the day after the surgery to ensure that there is no haematoma. If drains are placed, they are removed during this time.

Facial bandages are placed between 2 and 5 days. Sutures are removed 7–10 days later. The wounds are kept moist with antibiotic ointment such as Tetracycline 3% or Mupirocin ointment 2% (Figs. 37.24a, b and 37.25a, b).

#### **37.6 Complications and Management**

Post-operative complications of facelifts include postoperative haematoma, skin necrosis, sensory and motor disturbances, obvious scarring, seroma, alopecia, auricular deformity and dyspigmentation [21]. Detailed informed consent should be obtained from patients prior to the surgery.

#### **37.6.1 Haematoma**

A thorough medical history is needed prior to surgery. Antiplatelet medications such as Aspirin, Clopidogrel, Dipyridamole and powerful anticoagulation drugs such as warfarin will have to be stopped after consultation with the patient's prescribing physicians. Patients on herbal or traditional Chinese medications such as ginkgo biloba and Cordyceps will also need to be stopped before surgery.

Haematoma formation is by far the most common complication with some papers reporting up to 15% [21]. Expanding haematoma usually happens in the frst 24 hours and must be evacuated. Smaller haematoma can be aspirated, and pressure bandage is placed for pressure haemostasis. Meticulous haemostasis with bipolar diathermy is mandatory for facelift procedures. The fap and the underlying bed should be scrutinized for bleeding spots with a good head light or fbre optic light attached to a retractor. Brisk bleeding from larger vessels should be ligated. Adjunctive measures including fbrin glue [22, 23] and platelet gel and facelift bandages have been explored.

Large haematoma are a cause for concern and need to be evacuated. They can cause problems in healing including skin ischaemia.

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**Fig. 37.24** (**a**) Pre-operative profle view showing excess loose skin, jowling, submental fat and deep nasolabial fold. (**b**) Post-operative profle view after facelift and platysma plication. Excessive skin had been

#### **37.6.2 Skin Ischaemia and Necrosis**

Ischaemic changes and fap necrosis can occur due to circulatory disturbances. This can happen when the fap is too thin or had underwent extensive undermining and exuberant cautery, closed under excessive tension or compromised by excessively tight bandage compression. The incidence ranges between 1.1 and 3% [24]. Venous congestion or arterial obstruction can result in skin ischaemia and necrosis. Large unevacuated haematoma separates the fap off the underlying resected, jowls had been corrected and there was improved cervicomental defnition

bed during which perfusion is only by the vessels supplying the fap. This causes the areas furthest away from the perfusing vessels to be at risk of ischaemia.

Necrosis of the skin is more common in the postauricular than the preauricular region.

Application of nitroglycerin paste may help to encourage vasodilation when done in the early stages [25]. Conservative treatment to allow healing via secondary intention followed by laser, excision of the scar with repair via rotation faps can be carried out at a later stage.

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**Fig. 37.25** (a) Pre-operative profle view showing excess skin, slight jowling, submental fat and severe loss of neck defnition. (**b**) Post-operative profle view after facelift and platysma plication

#### **37.6.3 Obvious Scarring**

Scarring can occur when the wounds are closed under excessive tension or if the incisions are placed at an inappropriate position due to poor design. Skin slough and necrosis of the fap can lead to severe scarring. Patients who are more prone to hypertrophic scarring or keloids should be warned. Wound tension can develop and cause scarring if there is excessive removal of skin or if undermining of the fap is inadequate.

Treatment of scarring includes conservative treatment with antibiotic ointment such as Tetracycline cream 3% or Bactroban cream. This is followed by steroid injections such as triamcinolone acetate, application of silicone sheet or gel dressing. As the scar improves and stabilizes, it can be lasered, excised and revised.

#### **37.6.4 Sensory Disturbances**

Sensory disturbances occur invariably due to the dissection and separation of the facial planes during the facelift procedure, but this usually occurs temporarily and resolves in 1 year.

The most common sensory disturbance occurs to the great auricular nerve. The greater auricular nerve crosses the sternocleidomastoid muscle at approximately 6.5 cm inferior to the external auditory meatus and travels superiorly to supply the postauricular region.

Injury to this nerve can be temporary or permanent due to dissection over the postauricular, mastoid region and to a lesser extent in the cervical region. This results in numbness of the ear lobe and postauricular area.

Other forms of numbness can be found in preauricular region.

#### **37.6.5 Motor Nerve Disturbances**

Keeping away from the planes that the facial nerve travels in is the safest method to avoid motor nerve problems. The facial nerve branches course through the parotid gland and exits the parotid gland to travel deep to the SMAS layer before innervating the muscles of facial expression. Care

Facial nerve injury ranges from 0.4 to 2.6% [21]. The most common motor nerve damage is the marginal mandibular nerve followed by the temporal nerve and then the buccal branch. Neuropraxia from exuberant retraction, cautery heat and compression can result in temporary or permanent loss of the motor function. The marginal mandibular branch courses in the superfcial layer of the deep cervical fascia, deep into the platysmal layer, and may be damaged when dissecting in this region. The temporal branch of the facial nerve courses just deep to the superfcial temporal fascia and travels 0.5 cm anterior to the tragus and then obliquely to 1.5 cm above the lateral edge of the eyebrows.

#### **37.6.6 Ear Lobe Irregularities**

"Pixie or elf-like" ear is a stigma of facelift. The ear lobe should be repositioned in a tensionless fashion, and the ear lobe should be placed 15° posterior to the vertical axis of the pinna [6]. Over resection of the fap at the base of the auricle as well as failure to place subcutaneous stay sutures on the facial fap at the ear base can result in the ear being pulled inferiorly.

Pixie ears can be revised by releasing the base of the auricle and creating a new ear lobe.

#### **37.7 Conclusion**

The facelift remains the single most powerful method in facial rejuvenation for the moderate to advanced ageing face. It has developed from small elliptical incisions and closure to full facelift with simultaneous neck lift. A variety of techniques have been described contributing to its evolution including SMAS layer management, standard facelifts, composite facelifts, platysmal plication and smaller faps such as the MACS lift and S-lifts. The standard face and simultaneous neck lift can treat most of the problems of the mid and lower face as well as the neck. An intimate understanding of the anatomy of the face, appropriate choice of the facelift design and meticulous execution are paramount in giving the patient an ideal outcome while avoiding the possible complications.

**Disclosure** Authors have no fnancial conficts to disclose.

#### **37.8 Case Scenarios**

#### **Case Scenario 1** (Fig. 37.26)

A 67-year-old Caucasian lady presented with unhappy aesthetics of her face. She had had a considerable amount of sun exposure over the years. Her medical history was unremarkable.

Clinical features:

On examination she had multiple minor and major wrinkles on her face. On examination of the mid face, she showed descending SOOF and malar fat pads. She had prominent folding of the nasolabial fold and loss of mandibular border defnition. Her neck was a good shape for her age (Fig. 37.26a, b).

Treatment:

She underwent a standard facelift without a neck lift and simultaneous autologous fat augmentation malar, chin and perioral areas.

Post-operative fndings:

The post-operative profle shows aesthetically pleasing contour with an unoperated look (Fig. 37.26c, d). A majority of ageing changes have been removed. She ideally should undergo perioral laser resurfacing to improve the skin quality.

#### **Case Scenario 2** (Fig. 37.27)

A 73-old lady presented with ageing changes and was unhappy with the mid and lower face. She was concerned about the aesthetics of her neck (Fig. 37.27a, b).

She is an insulin-dependent diabetic and takes medication for hypertension.

Clinical features:

On examination, the mid face showed malar fat descent with prominent nasolabial fold. She had marked marionette lines, pre-jowl sulcus and prominent jowls. Examination of the lower face showed platysmal bands and loss of mandibular neck defnition with submental fat projection.

Treatment:

She underwent a standard face and neck lift with platysmal and SMAS plication.

Post-operative fndings:

Three month post-operative photograph shows correction for the ageing changes and a pleasing facial and neck profle (Fig. 37.27c, d).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 37.26** Standard face and neck lift with platysmal and SMAS plication. (**a**, **b**) Pre-operative appearance demonstrating wrinkles in frontal and profle view. (**c**, **d**) Post-operative appearance demonstrating wrinkles in frontal and profle view

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 37.27** Standard face and neck lift with platysmal and SMAS plication. (**a**, **b**) Pre-operative appearance demonstrating wrinkles in frontal and profle view. (**c**, **d**) Post-operative appearance demonstrating wrinkles in frontal and profle view

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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## **Rhinoplasty**

Nasir A. Nasser

#### **38.1 Introduction**

The nose occupies the centre of the face and receives enormous attention as a key aesthetic element. It is also an important organ contributing to vital functions of breathing and olfaction. A nose with ideal proportions creates a harmonious balance of aesthetic and psychological wellness. Whilst a rhinoplasty can signifcantly improve the quality of life of patients, there may be associated complications and undesirable outcomes. It is imperative that the surgeon desiring to practise the art and science of rhinoplasty should be familiar with the essential basics before embarking on this journey.

The aim of this chapter is to provide a clinical overview of the spectrum of rhinoplasty in an easily comprehensible manner. The primary section is focussed on the key elements of anatomy, diagnosis and documentation prior to any surgical procedure on the nose. Basic operative techniques including approaches, septoplasty, osteotomies and grafts are described in the next section. The management of most common nasal deformities is covered in the last section.

#### **38.2 Surgical Anatomy of the Nose**

The nose is a complex anatomic unit composed of skin, subcutaneous tissue and fbro-fatty tissue draped over a complex osteocartilaginous framework [1]. Understanding its overall morphology along with other characteristics helps in accurate diagnosis and management of various deformities. Based on the framework, the nose can be divided into exter-

N. A. Nasser (\*)

nal nose and internal nose. The important landmarks (Figs. 38.1A, B and 38.2) related to nasal anatomy are highlighted in Box 38.1.

#### **38.2.1 External Nose**

A. **Skin and underlying tissues**: The features of nasal skin including color, consistency and thickness can vary between patients and are important determinants of outcome of rhinoplasty. Skin thickness varies in different parts of the nose and at different stages of life. The average skin thickness is the greatest at the radix (measuring 1.25 mm) and the least at the Rhinion (0.6 mm) [2]. The supratip area has abundant sebaceous glands especially in adolescent males. Skin thickness is reduced in the columella and mid-alar area and increased in the alar base area. Both the thickness of the skin and the presence of sebaceous glands in the caudal half of the nose make it diffcult to achieve an ideal result in a predictable manner.

Beneath the skin and above the underlying osseocartilaginous framework are the layers of the superfcial musculoaponeurotic system (SMAS), fbromuscular layer, deep fatty layer, and periosteum/perichondrium [3]. The SMAS of the nose is the continuation of the sheath that extends across the entire upper half of the face with adipose tissues, vertical fbres and septi, extending to the skin. Under the SMAS is a layer of thin fbrofatty tissue that divides the superfcial and deep muscles of the nose [4]. The deep fatty layer separates the fbromuscular layer from the underlying nasal framework. Major blood vessels, lymphatics and nerves run within it. Deep to this layer is the periosteum of the nasal bones and the perichondrium of the cartilaginous frame. The avascular plane of dissection is in the supra perichondrial plane just below the fbrofatty SMAS layer.

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_38) contains supplementary material, which is available to authorized users.

Barts & London NHS Trust, Whipps Cross University Hospital, London, UK

**Fig. 38.1** Nasal anatomy landmarks—frontal view. (**A**) Clinical picture, (**B**) Line diagram: (**a**) Radix, (**b**) Dorsum, (**c**) Tip lobule, (**d**) Alar lobule, (**e**) Tip, (**f**) Alar base, (**g**) Columella, (**h**) Philtrum

©Association of Oral and Maxillofacial Surgeons of India

#### B. **External Vault**

The nose is divided topographically into thirds as shown in Figs. 38.3 and 38.4.

*Upper third:* The nasal bones constitute the upper one third. This part of the nose is pyramidal in shape, the narrowest portion being at the intercanthal line. Nasal bones vary in length and become thinner as they extend caudally toward the Rhinion. The nasal bones are attached to the frontal bone above at the radix which forms the frontonasal angle. They articulate with the ascending process of the maxilla. Caudally, the nasal bones overlap the upper lateral cartilages [Keystone area] [5].

*Middle third:* This contains the paired upper lateral cartilages (ULCs) and is referred to as the cartilaginous vault. The ULCs are fxed above to the under-surface of the nasal bones and fused with the septum, and they separate from the septum as they extend inferiorly. An important surface landmark in this region is the external lateral triangle; bounded above by the upper lateral cartilages, laterally by the frontal process of the maxilla, and caudally the cephalic border of the lower lateral cartilage. The angle between the caudal border of the upper lateral cartilage and the septum is usually 10–15° and constitutes the internal nasal valve (Fig. 38.5a, b).

*Lower Third:* The lower third or lobule of the nose is further subdivided into the tip, supra tip and infra tip regions. These specifc areas of the lobule are formed by variations in the shape, size, and angles of the lower lateral cartilages (LLCs). The form of the lobule is defned by the tip or apex of the nose. The area defning the overlap of the LLC and the caudal aspect of the ULC is called the "scroll" area and has a fbrous attachment. The size of the scroll area along with the slope of the lateral crus contributes to the bulbosity of the lobule.

The lower lateral cartilages have four essential components: the medial crus, intermediate crus, dome and the lateral crus (Fig. 38.6a, b, c): The cephalic edge of the domal segment of the intermediate crus is responsible for the aesthetic point known as the pronasale. The supra tip is immediately cephalic to the pronasale. The infra tip is located between the pronasale and the apex of the nostrils. The infra tip region should have a gentle curve that

#### **Box 38.1 Rhinoplasty landmarks**



©Association of Oral and Maxillofacial Surgeons of India

#### **Fig. 38.3** External vault—lateral view

slightly projects inferiorly to the alar margins. The medial-lateral crura complex forms a tripod that is an essential concept to understand for correction of tip deformities. The lateral crura form the two cephalic lateral legs while the medial along with the intermediate crus form the caudal leg of the tripod (Fig. 38.7a, b, c).

*Medial crus:* The medial crus has two distinct segments: the footplate and the columella. The footplate varies in size and in the degree of lateral angulation, which governs the width of the columellar base.

*Intermediate crus:* It extends between the medial crus and the lateral crus. The length and width of the intermediate crus control the confguration of the infra-tip lobule.

*Dome:* The domal segment is the narrowest and thinnest portion of the lower lateral cartilage, yet is the most important in relation to the tip shape. In an ideal nose, the cephalic edges of the paradomal segments are in close approximation and the caudal portions are divergent. Whenever the cephalic margins diverge, they result in widening of the nasal tip. A wide domal angle with increased interdomal width results in a boxy tip.

*Lateral Crus:* It constitutes the larger component of the nasal lobule. It is narrow anteriorly, widens in the mid-portion and narrows again laterally. The anterior portion of this cartilage can curve with different angulations and controls the convexity of the ala. The lateral crus also provides support to the anterior half of the alar rim. This cartilage is usually oriented at a 45° angle to the vertical facial plane. Narrowing of the angle between the dorsum and the long axis of the lower lateral cartilage **Fig. 38.4** External vault—lateral view. Line diagram showing the three divisions

N. A. Nasser

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 38.5** Nasal valve; (**a1**, **a2**) line diagram, (**b**) clinical photograph

may cause dysmorphology of the tip called cephalic malposition or 'parenthesis deformity'.

Several fbrous attachments exist joining the cartilages to each other, namely, lower lateral cartilages to the upper lateral cartilage, from one lateral crus to the opposite in the supratip area (the Pitanguy ligament), dense fbrous bands between the caudal septum & the medial crura and between the medial crura themselves [6].

**Muscles** (Fig. 38.8): The muscles of the nose are divided by their functions into four categories; elevators, depressors, compressors, and dilators. The procerus, levator labii superioris alaeque nasi, elevates and shortens the nose. These muscles are important because they assist in opening the nasal valves. The depressor muscles consist of the nasalis and depressor septi. On contraction, this group of muscles adversely affect the tip rotation by displacing it inferiorly and elevating the lip superiorly [5]. The transverse nasalis muscle forms the compressor, while the dilator naris has the opposite function.

**Blood Supply and innervation**: Both external and internal carotid arteries contribute to the vasculature of the external nose (Fig. 38.9). The major blood supply is from

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 38.6** Lower lateral cartilage (**a1**, **a2**) Diagrammatic representation and (**b**, **c**) clinical pictures

three vessels: the dorsal nasal artery—a terminal branch of the ophthalmic artery, the angular and superior labial arteries from the facial artery. The lateral nasal artery (branch of the angular artery) forms a plexus with the dorsal nasal artery, branches of infra-trochlear artery, and the external branches of the anterior ethmoidal artery. A small contribution is also received from the lateral branches of the infraorbital artery.

Sensory innervation to the nose is provided by the maxillary and ophthalmic branches of the ffth cranial nerve [7].

#### **38.2.2 Internal Anatomy**

The internal nose is divided by the "midline" nasal septum. Anteriorly, the septum forms the medial boundary of the nasal vestibule whose lateral wall is formed by the lower lateral cartilages and their attachment to the pyriform rim.

The deeper part of the nasal cavity is bounded laterally by the medial wall of the antrum, medially by the osseocartilaginous septum, superiorly by the ethmoid and the sphenoid bones and inferiorly by the palatal process of the maxilla and

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 38.7** Nasal tripod; (**a**) clinical photograph, (**b**) line diagram showing medial crus (yellow), intermediate crus (red) and lateral crus (grey) (**c**) line diagram showing basal view

the palatine bones. There are thin, curved, bony prominences in the lateral wall called the inferior, middle, and superior concha. The cephalic portion of the lateral nasal wall is bound with the ethmoid cells, interposed between the lateral wall of the nasal cavity and the medial wall of the orbit.

#### **38.2.3 Nasal Septum**

The septum is partly cartilaginous and partly bony. The ethmoid perpendicular plate forms the upper bony septum and is continuous with the frontal bone and the cribriform plate. The lower bony septum is composed of the vomer and nasal crest of the maxilla (Fig. 38.10a, b).

The cartilaginous septum is formed by the quadrangular cartilage that extends from Rhinion to the supratip area and supports the dorsum and the tip complex. Inferiorly, the cartilagenous septum is attached frmly to the anterior nasal spine and the maxillary crest. The junction between the dorsal and caudal portion of the cartilaginous septum is called the "anterior septal angle". There is tenuous attachment of the perichondrium and periosteum at the junction of the bony and cartilaginous septum. The membranous septum lies above the cephalic margins of the paired medial crura. It encases fbrous bands between two layers of soft tissue covering and the depressor septi muscle.

**Fig. 38.10** (**a**) Anatomy of nasal septum, (**b**) line diagram with landmarks


#### **38.2.4 Lateral Nasal Wall**

The lateral aspect of the nasal cavity is composed of three anatomic structures: the inferior, middle, and superior turbinates. The inferior turbinate forms a boundary of the internal nasal valve, where its specially adapted erectile tissues regulate the air fow and facilitate heat and moisture exchange.

Branches of the anterior ethmoidal artery accompany the external nasal branch of the anterior ethmoid nerve, passing between the nasal bone and upper lateral cartilages, and supply the soft tissues of the dorsum and tip of the nose. The posterior ethmoidal branches supply the smaller area above the superior concha on the lateral wall and a corresponding area high on the septum [8]. The posterior part of the internal nose is supplied by branches of the sphenopalatine ganglion of the second division of the trigeminal nerve (the long sphenopalatine, the nasopalatine and part of the greater palatine nerves).

#### **38.3 Clinical Examination**

Clinical examination should be comprehensive and include the assessment of systemic diseases (Box 38.2) [9].

General examination would include ruling out any syndromic deformities [9]. Obtaining correct history of systemic disease and bleeding disorders are of paramount importance. The extensive vascular network in the nose, in the presence of a coagulation disorder, may predispose the patient to severe haemorrhage in the intra- or post-operative period.

Existing breathing diffculty or any allergy-related symptoms such as rhinorrhea, sneezing, watery eyes, itching and loss of sense of smell and taste are observed. Majority of successful rhinoplasties are reductive in nature; an undetected or uncorrected underlying airway compromise may cause further deterioration and convert an aesthetic concern to a functional predicament. If the presence of any sinus infections and headaches is not recorded preoperatively, the patient may attribute these conditions to rhinoplasty [10].

#### **38.3.1 Examination of the Face**

The face in the frontal view is divided into thirds and ffths for assessment of proportion and harmony of various structures (Fig. 38.11a, b, c). In the upper third, the intercanthal distance and interpupillary distance is important in assessing the nasal bones, dorsum and radix. For a proper facial balance, the malar bone, maxilla, mandible and the nasal bones should be in an optimum spatial relationship. The length of the upper lip, its position during rest and smile, upper incisor show and its proportion in relation to the rest of the face are also assessed. The nose and chin may have a paradoxical relationship whereby a patient may have an overprojected nose and at the same time an underprojected chin and vice versa.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 38.11** (**a**)–(**c**) Examination of face and nose; frontal, lateral, basal. (**b1**) Ni - Ideal nasion, Ti Ideal tip. (**b2**) STB - Supra Tip Break, CLA - Columella Labial Angle. (**b3**) Nasal Length is measured from nasal radix to nasal tip (A–B), Nasal projection (C–B) is length from Naso-labial junction to nasal tip. The ratio between AB and CB (Goode's Ratio) should be ideally 0.55 to 0.60

#### **38.3.2 Examination of the Nose**

Visual analysis of the nose along with careful palpation allows the surgeon to assess the morphology and thickness of the skin and soft tissue envelope.

Frontal, profle and basal views should be used to assess the various components of the nose discussed above, individually.

#### **38.3.3 Photographic Assessment**

Patient's photographs are an important component of preoperative analysis and planning of the procedure. In addition, pre- and post-operative photographs are crucial for outcome monitoring and are indispensable from a medicolegal point of view [11]. With the advent of 3D imaging, image fusion and photogrammetry, preoperative and postoperative features can be compared in all dimensions [12].

There are four important photographic views that are used for analysis of the nose, namely, frontal, basal, lateral (at rest and smiling) and oblique views (Fig. 38.12). Photographs are standardised in relation to the Frankfurt horizontal plane. All four views are evaluated for the assessment of the facial horizontal thirds and vertical ffths. The quality of skin (thickness and Fitzpatrick type) and facial symmetry are also studied using all the views. The basic focus lies in the study of the loco-regional anatomy and the inter-relationships of the structures. The pictures are evaluated to assess any discrepancies in size, deviations or dorsal hump that may be immediately evident and recordable.

#### • **Frontal view**

The length, width and the tip characteristics are well observed on the frontal views. The width is individually assessed in the upper, middle and lower thirds of the nose. Frontal views also show a straight or a crooked nose. The presence of a dorsal hump or a saddle deformity is noted as these may provide an illusion of the nose being narrow or wide, respectively. The presence of a truly wide nose may also demonstrate features of pseudo/true hypertelorism.

The dorsal aesthetic lines should be studied in detail. They follow the eyebrows across the radix and along the dorsum to end at the tip defning points on either side.

©Association of Oral and Maxillofacial Surgeons of India

The lines should be almost parallel with a smooth divergence at the brow but without any visible or perceptible breaks.

The nasal tip is assessed for symmetry and defnition. The tip is also assessed for features of boxy appearance, bulbosity or bifdity. The alar base, ala and columella are also evaluated. The formation of a gentle "gull in fight" form should be appreciated for the relationship of the ala and the infratip lobule. An exaggerated curve may be indicative of a retracted ala or a plunging lobule. The position and insertion of both ala and their symmetry and direction are also noted.

#### • **Basal view**

Assessment should include the study of lobule, columella, ala and the alar base. Emphasis should be placed on the evaluation of the triangular shape of the nasal base, symmetry and the ratios, namely, the columella/lobule ratio and the lobule to ala ratios. The nasal base should present as an isosceles triangle with a rounded apex. The alar sidewalls should demonstrate a gentle fare. Poor triangular form or a trapezoidal form is indicative of a broad dome. Nostril symmetry and the angulations are studied next. The nostrils are angulated at 30–45° to the midline and are pear shaped. The caudal septum is assessed for straightness and its position in relation to the maxillary crest and anterior nasal spine. The alar base width, fare and insertions are also assessed in this view.

#### • **Profle view**

Key points that need to be evaluated from the lateral view include (1) a dorsal profle that may demonstrate a saddle/ hump and the supratip break, (2) evaluation of the chin and mentolabial sulcus, (3) projection and rotation of the nasal tip, (4) nasal length, (5) assessment of the radix and (6) columellar show with double break.

The ratio of nasal projection is evaluated by the method of Goode. The ideal ratio between the line joining the tip defning point and alar-facial groove tangent, to the line dropped from the nasion to the alar facial groove should be between 0.55 and 0.60. Rotation of the nasal tip is approximately considered 90o in Caucasian males and between 90 and 95° in Caucasian females.

The length of the nose is relative to the person's facial profle and general stature. It may be categorized as the central nose length from the nasion to the nasal tip and lateral length from the nasion to the alar rims. A short or long lateral length may refect as retracted or hooded ala, respectively. The nose may also show a relative increase or decrease in length depending on the depth of the radix. A deep radix may make the nose look short while a shallow radix makes the nose appear long.

The columella is also assessed for over- and undervisibility with the evaluation of a columellar double break that is formed by the junction of the medial and intermediate crus.

#### • **Oblique view assesses the volume of the tip lobule and Brow tip aesthetic line.**

Assessment of the oblique view may not provide objective details. However, the nose is most viewed at this angle thus making it an important view to assess the aesthetic balance of the face and nose. Important features that need to be assessed in this view include soft tissue facets, lateral aspect of the nasal bones, nasal length, dorsal contour and tip projection.

#### **38.3.4 Investigations**


#### **38.4 General Operative Techniques**

#### **38.4.1 Surgical Approaches for Rhinoplasty**

Rhinoplastic approaches: (1) open approach or the open structure rhinoplasty approach and (2) closed or the endonasal approach.

Open approach involves an external cutaneous incision while the closed approach involves intranasal incisions only (Fig. 38.13a, b).

Closed (**b**) approach

©Association of Oral and Maxillofacial Surgeons of India

Choice of incision is based on the clinical problem to be corrected and the exposure required. The ideal incision must enable adequate and easy access to the nasal architecture without compromising the nasal structures. The differences between the different types of incisions are highlighted in Table 38.1.

#### A. **Open structure rhinoplasty**

The open structure approach is employed when extensive reconstruction is required. There is more emphasis on the preservation and realignment of structures of the lower third of the nose and also achieving balance of the nasal "tripod".

The open approach involves the use of a marginal and mid-columellar incision (Fig. 38.14b)

	- Rethi transcolumellar incision 1931 (across the apex of the nostril aperture)
	- Sercer "nasal decortication" approach—1957
	- Bardach columellar base incision extending into prolabium (reserved for cleft rhinoplasty)

The **indications** for the open structure approach are highlighted in Box 38.3.

#### B. **The endonasal approach** (Fig. 38.14a)

Nondelivery/Partial delivery and delivery approaches (Fig. 38.16a, b).

1. **Nondelivery approaches are employed when** minimal reduction of the lateral crus or mild cephalic rotation of the tip complex is indicated.

The technique in turn may involve either the cartilage splitting approach or the retrograde eversion approach.




©Association of Oral and Maxillofacial Surgeons of India

then dissected off the overlying SSTE permitting the delivery of the LLC chondrocutaneous unit as a bipedicled fap. Improperly positioned intercartilaginous incision may predispose to scarring at the valve area.

#### **Incisions for the endonasal approach**

	- Hemi-transfxion
	- Bilateral transfxion—partial/full

788

©Association of Oral and Maxillofacial Surgeons of India

#### **Box 38.3 Indications for open Rhinoplasty**


#### **Indications for the endonasal approach**


The endonasal approach is, however, unsuited for the novice surgeon and does depend on the surgeon's experience and prior training in Rhinoplasty for optimal outcomes.

#### **38.4.2 Grafting in Rhinoplasty**

Reduction rhinoplasty can weaken the underlying nasal tip framework with subsequent buckling and late structural deformity. Cartilage grafting during primary and revision procedures helps to prevent such a secondary deformity [14–17]. An open technique is preferred as it offers better visualization for placement of grafts. The grafts used in rhinoplasty can be summarised as follows (Fig. 38.17a, b) (Tables 38.2 and 38.3):

#### **38.4.3 Septoplasty**

#### **38.4.3.1 Deformities of Nasal Septum**

Deformities of the nasal septum may either be congenital or acquired. They are classifed as shown in Box 38.4.

Septal deformities depend on alterations in the growth and direction of growth of the septal cartilage.

Deformities of the nasal septum may present clinically (Fig. 38.18a, b).


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 38.17** Sources of cartilage graft; (**a**) septal cartilage graft (**a1**) anatomy of septum (**a2**) marking for cartilage harvest preserving L shaped dorsal strut (**a3**) incision for cartilage harvest (**a4**) harvested cartilage (**a5**) carving of harvested cartilage and (**b**) Harvest of auricular cartilage; (**b**)- marking on the ear (**b2**)- incision (**b3**)- refection of sub perichondrial fap to expose cartilage (**b4**) cartilage harvest (**b5**) closure of donor site

#### **Table 38.2** Autologous graft materials


#### **Table 38.3** Alloplastic graft materials


	- Cleft lip and palate

#### **Acquired:**

	- Incorrect or aggressive rhino/septal surgery. Lefort I maxillary impaction with inadequate trimming of septum

#### **38.4.3.2 Sequencing for Treatment**

The sequence to be followed for planning a proper septoplasty includes


#### **38.4.3.3 Surgical Approaches**

Septoplasty may be performed in conjunction with a formal rhinoplasty using an open or closed approach.

Closed approaches for septoplasty include;


#### **38.4.3.4 Surgical Technique** (Fig. 38.19a, b, c)

The local anaesthetic solution is infltrated with adrenaline for optimal haemostasis. This not only provides a clear feld for surgery but also aids in developing planes by the process of hydrodissection. An incision is made at the caudal margin of the septal cartilage, which may be unilateral or bilateral. Cautious, careful, unhurried dissection in the correct anatomical plane is done, using sharp precise instrumentation (Cottle/Masing, Freer or Joseph's elevator). It is imperative to identify and stay in a bloodless sub-mucoperichondrial plane. The light blue colour of the septal cartilage ensures the correct plane of dissection. An anterior tunnel is frst made, followed by an inferior tunnel to expose the entire septum. The plane is then expanded and separated further with a Killian forceps. This offers bilateral exposure of the dissected tunnel and the septum. Sharp curvatures, angles and fracture lines are negotiated carefully also bearing in mind that the transition zone between the mucoperichondrium and the mucoperiosteum is an area vulnerable to tears. Tears over the mucoperichondrium require careful repair with vicryl sutures on a round body needle. However, tears in the inferior tunnel overlying bone need not be sutured and may act as drains. The fap elevation is extended posterior to chondrovomerine and chondroethmoid junctions for complete exposure of the bony septum.

Bony spurs or angulations and bends are identifed, which may contribute to airway block. The osteocartilaginous junction is then separated to free the septum in the posterior aspect. Takayashu forceps are used to nibble away any bony/cartilage spurs. This may also be performed using thin chisels and osteotomes. Buckling of the septum may be corrected by resection of overhanging cartilage in the caudal aspect. Adequate relief thus allows the passive return of the septum to midline. Measures such as scoring, suturing or the use of PDS sheets/cartilage grafts may be required to correct and straighten residual curvatures. Harvest of septal cartilage may be performed at this juncture and should be done posterior to the key area (imaginary vertical line joining the tip of the nasal bone and the anterior nasal spine). Stabilisation to the midline is achieved by the use of a PDS suture anchoring the dissected septum to the anterior nasal spine. The faps are reapposed with one or two transfxion sutures to prevent septal haematoma. Nasal packing is outdated and has been replaced by silastic sheets and intra-operative control with Merocel packs.

Advantages of the endonasal approach include


**Fig. 38.18** Deformities of nasal septum; (**a**) tension nose and (**b**) saddle nose

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Disadvantages of the endonasal approach are


7. Increased risk for secondary deformities like saddling

#### **38.4.4 Nasal Osteotomies**

Nasal osteotomies are often required during correction of deformities of the nose as well as an adjunct to procedures which involve correction of the osseocartilaginous vault.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 38.19** Septoplasty intra-operative steps. (**a**) the part of the septum anterior to the line dropped from the tip of nasal bone (NB) to the anterior nasal spine (ANS) has tobe preserved. (**b**) Dysjunction of the cartilaginous septum from the bony septum. (**c**) Septal repositioning with sutures to the midline crest of the maxilla

#### **38.4.4.1 Indications for Nasal Osteotomies**


Different types of nasal osteotomies (Fig. 38.20a, b) are utilised for a variety of clinical indications [21, 22]. They are enumerated in Box 38.5.

#### **38.4.4.2 Armamentarium for Nasal Osteotomies**

	- Straight osteotomes—2 mm microosteotome
	- Curved osteotomes
	- Guarded osteotomes—Nievert, Silver
	- Angled blade osteotomes—Murray-Parkes
	- Notched osteotomes—Walter
	- Oscillating/reciprocating saws
	- Piezo saw

#### **38.4.4.3 Surgical Technique**

The different techniques for performing nasal osteotomies are (1) endonasal, (2) percutaneous, (3) endoral and (4)

nasofrontal

#### **Percutaneous technique** (Fig. 38.21a, b, c)

The percutaneous technique involves the completion of a lateral osteotomy and a transverse root(superior) osteotomy. The local anaesthetic solution is infltrated with adrenaline 10–15 min earlier for good haemostasis.

The sites of the lateral and superior osteotomies are marked on the skin. The cephalic end of the cross-over of these two osteotomies should be kept no higher than the level of the intercanthal line.

A small 2–3 mm stab incision is made on the skin at the middle of the lateral osteotomy marking. The incision is deepened down and to bone. The osteotome is swept along the entire length of the marking to provide good release of the skin and subcutaneous tissue and keep the angular artery away from the line of osteotomy. The osteotome is then positioned supraperiosteally at 2 mm intervals and struck with a mallet to produce an interrupted line of punch holes. The osteotomies are started at the pyriform rim and continued superiorly to the nasofrontal junction. The same technique is followed for the transverse root(superior) osteotomy. The contra-lateral nasal wall is osteotomised in a similar

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 38.20** Types of osteotomies. (**a**) Endonasal and (**b**) Percutaneous

#### **Box 38.5 Osteotomies types**

	- Low to high
	- Low to low
	- Fading paramedian
	- True median
	- Vertical
	- Horizontal

fashion. Once this is completed, the nasal bones are held with frm/controlled pressure between the thumb and the fore-fngers of both hands over a gauze square and then fractured along the already osteotomised punch holes. Moderate pressure over the wound helps with haemostasis and prevention of ecchymosis. No sutures are required and the skin is dressed with a Steri-Strip.

**Complications** include comminution, unpredictable fracture line, loss of lateral wall support, avulsion/displacement of upper laterals, step deformity, residual deformity and failure to in fracture/mobilise nasal bones.

**Fig. 38.21** Steps in nasal osteotomy. (**a**) Start of the lateral osteotomy. (**b**) Osteotomy marking on skull. (**c**) Movement of the osteotome for lateral osteotomy

©Association of Oral and Maxillofacial Surgeons of India

#### **38.5 Surgical Management of Basic Nasal Deformities**

#### **38.5.1 Dorsal Hump Deformity**

The dorsal hump is the most common problem for which a patient may seek rhinoplasty. Based on the anatomical units involved, three main types of dorsal hump may be identifed [23, 24];


#### **38.5.1.1 Types of Dorsal Humps**

Dorsal humps can also be categorised as true and pseudohumps. True humps may occur isolated or may occur in conjunction with other nasal deformities. The pseudohump may produce a relative appearance of a dorsal hump, while in reality, the appearance may be due to a high anterior septal angle, supratip prominence or tip ptosis (Box 38.6).

#### **38.5.1.2 Clinical Assessment of a Dorsal Hump**  (Fig. 38.22a–d)


#### **38.5.1.3 Armamentarium for Dorsal Hump Reduction**

The armamentarium required for dorsal hump reduction are shown in Box 38.7.

#### **Box 38.6. True vs. Pseudo humps**


#### **38.5.1.4 Dorsal Hump Reduction (Profle Lowering)**

The procedure for dorsal hump reduction (profle lowering) is facilitated by two important steps, namely, (1) bony hump removal and (2) cartilaginous hump removal.

#### **Bony hump removal** (Fig. 38.23A–K)

En-bloc bony or cartilaginous hump removal requires experience as there is a high risk of excessive reduction when the surgeon may be inexperienced. The procedure begins with infltration of lidocaine 2% with 1 in 100,000 adrenaline.

After exposure of the osteocartilaginous vault is completed, the osteotome is engaged at the caudal edge of the nasal hump (osteocartilaginous junction) and the bone is removed using an osteotome and mallet (18 oz Heath mallet) with frm blows to follow a careful alignment. It is better to always under-reduce, rather than over-reduce as it may cause severely compromised results. The dorsal edges can then be rasped down to the desired extent. Care is taken not to rasp the cartilage as it may produce irregularities, tears or avulsions.

When separation of a large hump is desired, placement of a superior stop-cut as described by Tardy allows precise and clear separation at the desired level. Diamond rasps are used to smooth irregularities at the dorsal edge of the nasal bones. Removal of an osteocartilagenous hump results in an open roof deformity of the nasal dorsum, which needs to be closed with an osteotomy [23].

#### **38.5.1.5 Complications**

	- Bony saddle
	- Loss of support to ULC

#### **Box 38.7. Bony vs. Cartilaginous hump, (Armamentarium)**


	- Residual hump

carbide rasps (Rees) • Pull rasp/push rasp (Daniel)

• Diamond rasps Power saw • Rhinobur (Toriumi) • Piezoelectric saw

– Failure to follow dorsal line: superior bony spur

#### **38.5.1.6 Preservation Technique of Hump Removal (Regnault & Daniel)**

This technique advocates aggressive removal of the large hump with osteotome. The under-surface of the hump is then reduced extracorporeally with a bur. The reduced hump is replaced in the dorsal defect. This obviates the need for nasal osteotomy and provides optimal results of a corrected dorsum.

#### **38.5.2 Saddle Nose Deformity**

A saddle nose deformity is defned as a wide and fat nose with a concavity on the nasal dorsum.

Classical clinical presenting features of this deformity are


#### **38.5.2.1 Classifcation**

Saddle nose deformity can be classifed based on the underlying structural problem into

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**Fig. 38.22** Dorsal hump - clinical presentation. (**a**) Profle and (**b**) frontal pictures of patient 1. (**c**) Profle and (**d**) frontal pictures of patient 2


The causes responsible for saddle nose deformity are many, namely, septal hematoma following trauma, iatrogenic—inappropriate surgery to the septum, bony vault &

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 38.23** Hump reduction technique: Armamentarium (**A**, **B** & **C**). Surgical technique (**D**, **E** & **F**) Removal of the dorsal hump with the osteotome, (**G**–**K**) Preparation of the "open roof" deformity for closure

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 38.23** (Continued)

middle vault and substance abuse (cocaine), diseases like congenital syphilis/leprosy and racial predisposition— African, Afro-American, and Asian.

#### **38.5.2.2 Clinical Features**

The salient features (Fig. 38.24) demonstrable on a patient with saddle nose deformity are enumerated in Box 38.8.

The septum may exhibit deformity with twisting/defciency or at times may be totally absent.

The skin and soft tissue envelope may show a "concertina" effect due to loss of structural support.

#### **38.5.2.3 Surgical Management** (Fig. 38.25a, b)

Surgery for the correction of saddle nose deformity may be planned in a staged manner with the frst stage involving the correction of the foundation of the nose and the second stage involving the aesthetic makeover [25, 26]. The aim of the procedure is to re-establish the tension between the nasal tip

#### **Box 38.8 Features of saddle nose deformity**

#### **Frontal:**


#### **Profle:**


#### **Basal:**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 38.24** Saddle nose clinical photo

complex and the dorsum, which has been lost due to the concertina effect.

Surgical correction involves three essential steps that are independent of each other.


This procedure involves the use of strong and robust cartilage grafts. The eighth rib provides an adequate amount of cartilage which is ideal for this situation. Ear cartilage lacks rigidity, while banked cartilage tends to undergo resorption.

#### **38.5.3 Correction of the Deviated Nose**

Deviated noses can be of two types


#### **38.5.3.1 Aetiology**

The most common causes of a deviated nose


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 38.25** Saddle nose-intra op. (**a**) intra-operative pictures demonstrating use of rib cartilage for dorsal nasal reconstruction. (**b**) Landmarks for rib harvest

#### **38.5.3.2 Clinical Features**

Clinical features of a deviated, bent or crooked nose include both functional and aesthetic issues

	- (a) Frontal
		- Deformity of the nasal pyramid
		- Twisting or angulation of the nose
		- Constriction or bulge at the middle vault
		- Bending of the nose showing midline discrepancy
		- Unequal height of the nasal bones
		- Tip deformity secondary to the loss of septal support/angulation
	- (b) Profle
		- Patient may present with a dorsal hump or a saddle deformity
		- Loss of tip projection
		- Nasal tip ptosis
		- Retraction of the columella

#### (c) Basal


#### **38.5.3.3 Treatment** (Fig. 38.26a–g)

Septorhinoplasty is required to correct the deformity. Some prefer single-stage correction, while others may choose staged procedures (frst stage septoplasty followed by a second stage external deformity correction). However, a singlestage correction is preferred. This is usually performed using an open structure approach with exposure and separation of the septum from the upper lateral cartilages. Straightening of the septal cartilage is performed by excision and/or partial division of the cartilage and may be followed by scoring or sutures as indicated. Some surgeons prefer the use of a PDS sheet to splint the corrected septum. However, costal cartilage may be harvested for reinforcement of the straightening

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 38.26** Techniques of reduction of crooked nose deformity with twisting/angulation of septum, (**a**) differential reduction of hump prior to ostetotomy, (**b**) septal repositioning, (**c**) digital reduction/manipulation after osteotomy, (**d**) line diagram of "low-to-low" osteotomy, (**e**) intraoperative picture with osteotome positioning (low-to-low), (**f**) line diagram of "nasal bone osteotomy", (**g**) intra-operative picture with osteotome positioning (nasal bone osteotomy)

and to provide a spreader effect to correct the nasal valve simultaneously. Osteotomy of the nasal bones is often required to correct the angular deformity of the bony vault. A tip plasty may be necessary in most cases to correct the nasal tip tripod deformity secondary to nasal deviation.

It is to be borne in mind that the results for the correction of deviated noses are not always satisfactory. There is a possibility of residual deformity, recurrent deformity, loss of tip support and saddling.

#### **38.5.4 Tip Plasty**

The nasal tip is the centre of focus for both nasal anatomy and aesthetics. It is a very important anatomical subunit and can be most challenging to refne surgically.

Nasal tip deformities may show varied morphology and diverse clinical presentations (Fig. 38.27a–f). They may occur in isolation or concomitant with deformities of the dorsum or septum.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 38.27** Types of tip deformity. (**a**) Wide bulbous tip, (**b**) ball-ended amorphous tip, (**c**) plunging infra-tip lobule, (**d**) amorphous bulbous tip with deviation and constriction of right lower middle vault, (**e**) over-projection of nasal tip owing to prominent ANS & overtly long lower lateral cartilage with normal naso-labial angle, and (**f**) nasal tip over-projection with upward over-rotation

Tip deformities can be enumerated as follows as in Box 38.9.

#### **38.5.4.1 Wide Nasal Tip**

A tip is considered abnormally wide when the width of the tip is greater than the width of the dorsum. Normally, the tip width is equal to the width of the dorsum.

This can be further subclassifed as mild, moderate or severe.

A wide nasal tip may be caused due to three morphological alterations:


#### **Box 38.9 Types of tip deformities**


#### **Surgical management**

Surgery for the nasal tip can be performed either through a closed or open structure rhinoplasty approach. This may depend on the clinical indications involved as well as the skill and experience of the operating surgeon. Steps for correction of a wide nasal tip include reduction of the interdomal width by placing a permanent interdomal suture with 5-0 prolene or 5-0 PDS (semipermanent). This is followed by the creation of a new domal angle (transdomal suture followed by the interdomal suture). One should also consider surgical removal/excision of a segment of the intermediate crus for better tip defnition (Fig. 38.28a, b).

#### **38.5.4.2 Bulbous/Boxy Tip** (Fig. 38.29)

Bulbous tips have problems associated with thick SSTE (skin & soft tissue envelope), excessive subcutaneous fat, strong convex and bulky lateral crura and a concertina effect of a shortened nose in general.

#### **Surgical management**

This involves careful degloving of the SSTE leaving the subcutaneous fbrofatty tissue on the lateral crura. Careful defattening and thinning of the subcutaneous plane should be performed. A modest cephalic trim is performed to correct the large and bulky lateral crura. As this is a more general deformity involving not only the tip but also the associated SSTE, a careful distribution of volume to produce balance may be required. This helps camoufage the deformity to a great extent while improving outcomes.

Excessive or injudicious defattening of the nasal tip may cause ischemia/necrosis of the skin of the nasal tip,

©Association of Oral and Maxillofacial Surgeons of India

blanching of the tip skin with exposure to cold, contour irregularities of the underlying cartilage to become visible and may also lead to the skin pores communicating to the underlying tissues.

#### **38.5.4.3 Overprojected Nasal Tip** (Fig. 38.30a–c)

Nasal projection is defned as the distance along a perpendicular line from the vertical facial plane to the anterior most point on the nasal tip. The nose when not in normal facial balance can either be overprojected or underprojected.

The key to correction of the overprojected nasal tip is to establish the cause. This may be due to the increased length

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 38.29** Bulbous tip clinical

(**a**) profle of patient 1, (**b)** profle of paitent 2 at repose and (**c**) profle

of patient 2, smiling

of the anterior nasal spine, excess caudal septal height or overtly long alar cartilages.

#### **Surgical management**

Surgery for the overprojected nose should be performed through a full bilateral septal transfxion incision with the aim of deprojecting the nose by 4–5 mm. The anterior nasal spine is reduced judiciously followed by the resuspension of the upper lip to the ANS. The anterior septal angle is lowered to achieve further deprojection. Deformities of the alar cartilage may be varied and may require division and overlap of the medial crura, division or resection of the medial footplates. A lateral crural overlap with resection of a segment is performed 1 cm from the dome. Domal resections are to be avoided as they may produce secondary deformities: irregularities, angulation, and bossa formation. They may produce a sharp angulation with a pointed tip (pinched nose), which may require a shield graft for tip camoufage. Care should be taken to avoid/prevent loss of tip support during these manoeuvres.

#### **38.5.4.4 Underprojected Tip** (Fig. 38.31a, b)

It is important to establish the cause for underprojection prior to treatment. Causes of underprojection may include


©Association of Oral and Maxillofacial Surgeons of India


#### **Surgical management**

Surgery for the underprojected nose should follow the sequence provided below: the columella is strengthened with a strut graft, a transdomal suture is placed to project the dome. A shield, cap or an umbrella graft may be used to increase tip projection. A caudal septal extension graft is added to strengthen the septal support and increase projection. Finally, a transcolumellar suture is performed through the medial foot-plates. In patients with the defciency of the premaxilla or the total bony maxilla (cleft maxillary hypoplasia) where loss of bone support contributes to the loss of nasal projection, advancement of the maxilla or Onlay grafting of the premaxillary segment may offer the correct solutions.

#### **38.5.4.5 Over-Rotated Tip (Piggy Nose)**  (Fig. 38.32b)

Tip rotation denotes the angle formed by the columella to the upper lip. The point of reference here is the nasolabial angle. Deformities of the nasal tip related to the rotation can be either over-rotation or under-rotation (ptotic nose).

Over-rotation of the nose may arise due to various causes: post-traumatic (caudocephalic impact to the nose) or an inherently short nose. Over-rotation may also be a complication of prior rhinoplastic procedures due to overzealous caudal septal reduction, excessive cephalic trim of the lateral crura or injudicious lowering of the anterior septal angle.

#### **Surgical management**

Surgery for the correction of over-rotation of the nasal tip should include techniques for de-rotation of the nose like placement of a caudal septal extension graft and/or extension of the dorsal graft beyond the domes. These procedures require extensive cartilage grafting to lengthen the shortened nose.

#### **38.5.4.6 Under-Rotated Tip (Ptotic Nasal Tip)**  (Fig. 38.32a)

Under-rotation denotes cephalocaudal rotation of the nasal tip, which makes the tip point downward. This needs to be differentiated from an underprojected tip. However, occasionally both problems may co-exist. It is also important to identify the presence of pseudo-ptosis in which the tip is normal but a more prominent anterior septal angle makes the tip appear ptotic.

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**Fig. 38.31** Underprojected tip. (**a**) Clinical picture and (**b**) diagrammatic representation

Ptotic tips need to be examined both at rest and dynamically. The dynamic inferior movement of the nasal tip may occur due to the downward pull of a strong depressor septi muscle. Care should also be taken to look for any other associated deformities.

Causes for an under-rotated or ptotic tip may be hereditary as in the noses of people from the Mediterranean countries, developmental due to heavy SSTE and weak cartilages or the presence of excessive skin in the membranous columella. Patients with bilateral cleft lip deformities are predisposed to have underprojected and under-rotated noses due to columellar defciency.

Iatrogenic causes for tip ptosis include: poorly planned and executed septorhinoplasty with loss of septal support, inadequate maintenance of tip support or reattachment of the tip support structures. It may also be a complication following (1) prolonged intubation with the nasotracheal tube not anchored well and (2) tumour ablations with inadequate reconstruction.

#### **Surgical management**

Correction of the ptotic tip should be based on the anatomy involved. It is best to follow an algorithm for planning the surgical procedure. The structures contributing will enable us to plan and perform the correct procedure.


#### **38.5.5 Managing the Wide Ala**

The normal width of the ala falls within or just beyond an imaginary vertical line dropped from the medial canthus to the upper lip. The ala may be either narrow or wide. A wide

ala compromises facial aesthetics and is often a complaint for which the patient seeks help.

#### **38.5.5.1 Causes of Variations in Alar Base Width**

A wide alar base may be a characteristic of racial variations, for example, African and Asian races exhibit increased width of the alar base. It may also be wide in patients with congenital anomalies like cleft lip and palate. Wide alar base may also be due to iatrogenic causes like


#### **38.5.5.2 Clinical Features**

Patients with a wide alar base exhibit a nose that looks fat and broad; the alar columellar line may be straight and they may have an associated wide nasal tip. In the basal view, the nose presents with reduced tip projection and short or distorted columella. The alar side walls show increased bulk and increased fare, and the alar insertion into the nasolabial area may be horizontal or oblique. The alar sill

**Fig. 38.33** Wide ala surgery techniques. (**a**) Traditional Weir excision (leaves a notch deformity) and (**b**) modifed excision incorporating a lateral advancement which prevents notch deformity and restores continuity of alar rim

width may also show an increase. The premaxillary base that supports the alar complex may be normal, defcient or asymmetric.

#### **38.5.5.3 Evaluation**

The nose should be evaluated for the cause of alar widening. This is the basis on which the treatment may be planned. When there is a doubt regarding the width of the ala, it may be wise to abandon the idea during a primary rhinoplasty and perform the alar correction as an isolated secondary procedure.

#### **38.5.5.4 Surgical Treatment** (Fig. 38.33a, b)

Surgery for the wide ala needs to be sequenced after assessment of the cause; this may be a wide ala demonstrating


©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 38.34** Wedge technique for alar base reduction

of the scar. A medial fap excision technique as described by Sheen may also be a good alternative to this. The decision regarding medial repositioning of the alar base should be in accordance with Sheen, who recommends it only in cases of extreme lateral divergence.


#### **38.5.6 Septal Perforations**

Septal perforations are pathological defects in the nasal septum which form communications between the right and the left sides of the nasal cavity. These may present as anterior, mid-septal or posterior perforations (Fig. 38.35a, b).

The most common aetiological factors producing septal perforations are


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 38.35** Septal perforation; (**a**) clinical presentation, (**b**) intra-operative picture

#### **38.5.6.1 Clinical Features**

The occurrence of septal perforations also leads to a variety of sequelae that produce secondary deformities of not only the nose but also signifcantly affect the face and the oral structures. The nose may show a saddle deformity, columellar retraction and narrowing of the nasal valve. Furthermore, the loss of nasal cartilage and bony framework may lead to a concertina deformity of the skin envelope. Perforations may expand in an inferior direction with associated necrosis of the vomer and maxillary crest, thus causing a palatal fstula. Other symptoms include nasal airway block, nasal discharge, crusting, epistaxis, midfacial pain, and a characteristic whistling noise.

#### **38.5.6.2 Investigations**

Investigations for perforations of the nasal septum include a thorough clinical evaluation of the nasal cavity, oral cavity and the face for accurate diagnosis. The patient is also subjected to a rhinoscopy and a nasendoscopy for assessment of the intranasal deformity. This is followed by a biopsy from the margins of the perforation. A swab may also be performed for culture and sensitivity when there are signs of acute infection of the region.

#### **38.5.6.3 Treatment**

810

Treatment is initiated in a conservative form with counselling, wound care and topical medication. This involves abstinence from cocaine use with rehabilitation under supervised care. Regular inspection of the nasal cavity and nasal toileting with seawater douches. Topical administration of Naseptin cream alternating every 2 weeks with Bactroban (Mupirocin) ointment is mandatory prior to surgical intervention.

Surgical management (Fig. 38.36a, b, c) for septal perforations is extremely challenging and often give disappointing results. Any treatment is bound to be compromised due to resurgence of the cocaine addiction and poor vascular status of the involved anatomy resulting in a high incidence of residual defects after surgery.

There are also risks of total failure of procedures with secondary donor site deformities, adding to the post-surgical morbidity in these patients.

#### **38.5.7 Nasal Valve Problems**

To understand the problems associated with the nasal valve, it is important to see the distinction between the "nasal valve area" or the internal nasal valve, the "nasal valve" and the external nasal valve: The nasal valve area is the empty triangular space that is bounded medially by the nasal septum, laterally and superiorly by the caudal margin of the upper lateral cartilage and its attachment to the pyriform rim and inferiorly by the bony nasal foor. The nasal valve specifcally denotes the slit that is seen between the caudal end of the upper lateral cartilage and the nasal septum. Physiologically, the internal nasal valve is the area offering the highest resistance to airfow, and any deformities of this region may compromise the air-fow dynamics.

#### **38.5.7.1 Anatomy of the Nasal Valves**

The components of internal and external valves are projected in Box 38.10.

The aetiology of nasal valve problems are enumerated in Table 38.4.

#### **Box 38.10. Components of nasal valves**


#### **Table 38.4** Etiology of nasal valve problems


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**Fig. 38.36** (**a**–**c**) Septal perforation surgical technique

#### **38.5.7.2 Clinical Examination of Nasal Valve Problems**

It is extremely important to identify the exact location of the nasal obstruction to obtain the best surgical outcomes. This can be accomplished using


#### **38.5.7.3 Surgical Management**

Sequencing of treatment for the management of nasal valve problems should include certain empirical steps. The frst step is to perform an optimal septoplasty to relocate the septum to the midline. This is followed by straightening and strengthening of the alar sidewall using alar batten grafts and rim grafts. Narrowing of the columellar base may be performed in cases of true columellar widening. Collapse of the nasal valve can be corrected by the use of spreader grafts that help in widening. In certain cases, there may be webbing or scarring along the nasal valve area. This may need a "Z" plasty for release and correction. Finally, judicious removal of the inferior turbinate may be contemplated in indicated patients after due consultation with the ENT surgeon.

#### **38.6 Complications Following Rhinoplasty**

A sequela may be defned as a natural consequence following a disease process or a surgical procedure while a complication implies undesirable sequelae or process following surgery.

This section with dwell on the common sequelae and complications that may occur following rhinoplasty and will help providing tips for reducing or preventing complications.

Common sequelae following rhinoplasty may be tabulated as early and late in Box 38.11.


#### **Box 38.11. Complications of Rhinoplasty**

Most sequelae are self-limiting and may not require any active intervention. However, it is imperative to follow certain steps to minimise or avoid complications as discussed below.

The key to minimising or preventing unfavourable outcomes depends on proper case selection after a thorough evaluation of the patient both physically and psychologically (perceived complaint vs objective deformity). A good clinical examination should follow with optimal documentation (clinical analysis and photographs). The subsequent consultation should include obtaining informed consent from the patients after discussion of the indications and anticipated complications associated with the surgical procedure. It is important to understand our limitations and accept them while not refraining from seeking professional help/support when needed.

Complications in rhinoplasty may depend on the area of surgery and the procedure performed as indicated below:


The skin and soft tissue envelope may also show scarring, ischemia/discolouration and at times telangiectasia.

Management of complications may be necessary when the deformity is visible to both the surgeon and the patient. This necessitates revision or secondary surgery which may be indicated in about 5–8% of the patients. Even when indicated, it is better to wait for a year prior to attempting revisions or secondary interventions. This is to facilitate a careful assessment of long-term changes following the procedure and the fnal outcome prior to intervention.

#### **38.7 Conclusion**

Rhinoplasty in most realms is considered as the epitome of aesthetic surgical skill. This burdens the surgeon with the responsibility of performing the surgery with accurate planning and prediction of outcomes. It is also important for both the young surgeon and the patient to understand that the fnal outcome of the surgery is not in the immediate future but is a culmination of all the surgical manoeuvres and their response over a period of time. This is the same fact that makes rhinoplasty among the most diffcult to master. Rhinoplasty has transgressed from the early procedures of sole nasal reduction to encompassing not only the aesthetics of the nasal complex but also improvement of the function and establishing a balance for today's patient. This chapter is aimed to provide the reader with the basics of surgical techniques. Perhaps, this is one surgical skill where the surgeon still holds all the cards while the others are losing the battle to technology.

#### **References**


#### **Additional Reading**

Mladina R. The role of maxillar morphology in the development of pathological septal deformities. Rhinology. 1987;25(3):199–205.

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**Part XIII**

**Advances in Oral and Maxillofacial Surgery**

## **Lasers in Oral and Maxillofacial Surgery**

Shravan Renapurkar and Robert A. Strauss

#### **39.1 Introduction**

The frst successful demonstration of laser was performed by Maiman in 1960 who also predicted one of its uses to be in medical science [1, 2]. Decades after the frst medical use in the oral cavity and face, lasers are not just an adjunctive tool today but are an integral part of an Oral and Maxillofacial Surgeon's (OMS) armamentarium. Although CO2 laser has been the traditional workhorse for an OMS, advancement in the capabilities of CO2 lasers, as well as the development of other types of lasers, has helped grow their utility. Increasing use of lasers in turn has created greater evidence of its effcacy and safety record. Use of lasers has not only added advantages to conventional OMS procedures, as opposed to a scalpel, it has also given rise to newer procedures, which were not possible with conventional tissue-cutting tools.

### **39.2 Laser Physics**

Modern lasers are simple to use but a lack of knowledge on the physics of lasers, inadequate training and caution in handling lasers, can give rise to potential adverse outcomes and unwanted complications. The term "laser" stands for light amplifcation by stimulated emission of radiation and was frst used by Gordon Gould in 1957 [3]. The laser, as opposed to a regular light source, is composed of monochromatic, coherent and collimated beams, which, when they strike a suitable target, create photoacoustic, photochemical, photoablative, and photothermal effects. Laser light energy can undergo absorption, refection, transmission, and scattering based on the optical properties of the target tissue or matter. For surgeons, the most desirable action is absorption into the

Commonwealth University Medical Center, Richmond, VA, USA e-mail: srenapurkar@vcu.edu; rastrauss@vcu.edu

tissue, which creates the predictable photothermal outcome of coagulation and then vaporization of tissues [4].

The basic component of a laser unit includes a "laser cavity" where the laser beam is produced via the phenomenon of stimulated emission as postulated by Albert Einstein. The laser cavity is composed of an active medium, an excitation source acting as a pumping mechanism, and an optical resonator (Fig. 39.1). The active medium is the chemical (gas/ liquid/solid) that the type of laser is named after and is the material that undergoes stimulated emission. The photons of energy produced are collimated and amplifed to produce the laser beam, which is then delivered to the target tissues via an appropriate delivery mechanism, either a fexible fberoptic system, semifexible hollow waveguides, or articulated mirrored arms (Fig. 39.2a–c). Lenses focus the active laser beam to create a "focal point," the point at which the energy is condensed to the smallest area to create the maximum effect. Some fberoptic laser systems utilize a quartz or sapphire crystal at the tip of the fber to enable the beam to be absorbed by this crystal and allow contact with tissues at the tip of the fber, while others are used in a noncontact mode. A laser beam is an electromagnetic beam of radiation, which can fall anywhere in the spectrum of visible or invisible light. Nd:YAG, CO2, and erbium lasers fall into the infrared invisible spectrum; hence, they are often accompanied by a visible aiming beam, which helps the surgeon to know the point in the tissues where laser beam hits the target tissues. Aiming beams can be another low power laser or a regular light source [4] (Fig. 39.3).

The factors related to the use of lasers that are under control of the surgeon include the spot size, power, and time on target. The spot size of the laser is the width of the laser beam on target. At the focal point, the maximum energy is focused to produce the smallest spot size or the thinnest possible incision but to the greatest depth. When the tip of the laser delivery system is moved away from the tissues, the laser beam diverges causing a bigger spot size and the energy is then distributed over a larger area and the related depth is

**39**

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 817

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_39

S. Renapurkar (\*) · R. A. Strauss Department of Oral and Maxillofacial Surgery, Virginia

**Fig. 39.2** (**a**) Fiberoptic laser. (**b**) Hollow waveguide laser. (**c**) Articulated arm laser

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 39.2** (continued)

decreased [5]. Laser emission modes and the surgeon's hand speed can affect the temperature rise and effect in the tissues. Lasers can be emitted in "continuous-wave" mode or in a "pulsed mode." Lasers used in pulsed mode allow time for tissues to cool before the next pulse of laser radiation is started while continuous wave mode of laser must be stopped manually to allow the tissues to cool. The time between pulses can help avoid thermal effects on surrounding tissues or excessive thermal effect on target tissues. The lasers with pulsed mode of emission can be of two types, "gated pulsed" or "true pulsed." True-pulsed lasers are pulsed by a mechanism within the laser cavity, while the gated-pulsed lasers have a shutter-like mechanism outside the laser cavity [4].

#### **39.2.1 Advantages of Laser**

Lasers have obvious advantages, which make them superior to conventional cutting tools. An ability to provide better hemostasis is a great advantage for surgeons to maintain visibility and reduce blood loss. Since spot size, power, and time on

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 39.3** Low-level laser-aiming beam

target are regulated by the surgeon, lasers provide better control of desired tissue changes, which enhances the precision of surgery. Increased precision of the depth of tissue damage along with fewer myofbroblasts in laser wounds compared to scalpel wounds, allow for improved tissue healing and decreased scarring. The mentioned advantages are presumed to decrease postoperative pain with the use of lasers, although the pathophysiology for this effect is not well understood.

#### **39.2.2 Disadvantages of Laser**

Despite several advantages of lasers in surgery, the provider should make sure the benefts outweigh the risks and disadvantages. Hard-tissue lasers such as Er:YAG and Er:CR:YSGG do not match the speed of bone or tooth cutting as do conventional tools such as burs or saws. Soft-tissue healing after laser-assisted incision or excision is slower (although with decreased scarring) than tissue healing using scalpels. The associated learning curve and costs of the laser equipment add to the drawbacks of using lasers.

#### **39.3 Selection of Lasers**

The type of laser to be used is based on the laser's physical characteristics, interaction with the target tissues, and the goals of the procedure. For example, CO2 laser's excellent affnity for water, which is the main component of soft tissues, makes it the most widely used laser for soft-tissue surgical applications. The most commonly used CO2 laser is the 10,600-nm wavelength, although 9600-nm and other wavelength variants of this laser exist. The CO2 laser is currently the most ideal laser used for most intraoral and extraoral soft-tissue procedures. The absorbed energy causes vaporization of the intracellular fuid causing tissue vaporization, while lateral heat conduction causes contraction of collagen and closure of blood vessels of approximately 500 μ or less in diameter. High-power CO2 lasers are generally delivered via articulating arms, but new hollow waveguide systems suitable for offce use provide increased accessibility intraorally along with their ease of use [6, 7].

Other lasers include the Nd:YAG (a crystal of Ytrrium, Aluminum, and Garnet doped with the rare earth element Neodymium) laser, which functions in the near-infrared electromagnetic spectrum at 1064 nm, and has minimal water and superfcial tissue absorption leading to deeper tissue penetration. Hence, the Nd:YAG can be used for coagulation of deeper and larger (2–3 mm) diameter vessels. These qualities of Nd:YAG have led to its use in treating angiomatous or vascular tissue lesions, although this same lack of water absorption limits its utility for the OMS. Depending on the desired effect, the Nd:YAG laser can be used both in contact and noncontact modes [8–10].

The Er:YAG laser works at a 2940-nm wavelength and is even more highly absorbed in water than the CO2 laser leading to rapid absorption by the superfcial layers of tissue and minimal penetration. This can be an advantage in some cases but also means that this laser is less effective on tissue than the CO2 laser. As an example, when used for cosmetic skin resurfacing it shows much more superfcial effects, which heal quite quickly, but also shows much less of a result than CO2 laser does. For this reason, it has fallen somewhat out of favor for this purpose [11–15]. Owing to limitation of its thermal effects mostly in superfcial layers of soft and hard tissue, Er:YAG laser has become popular in implant dentistry. It can be used on both soft and hard tissues and fnds its application in bone preparation, second-stage surgery, treatment of peri-implantitis. Being refected off the surface, it has minimal or no apparent adverse effects on dental implants [16].

The Holmium:YAG laser is generated at a 2100-nm wavelength, which enables it to be delivered in contact mode via fberoptic cable also demonstrates very little water absorption but is well absorbed by other tissue components [17]. This allows it to be transmitted through water-rich environments while having similar tissue effects as the CO2. Minimal lateral thermal damage, precise depth of cut, and good coag-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 39.4** Diode laser

ulation combined with its ability to be used in presence of saline/lactated Ringer's solution makes it the preferred laser for operative TMJ arthroscopy [18].

Diode lasers at wavelengths between 805 and 980 nm have been reported to be compact, inexpensive, and easy to use in OMS procedures (Fig. 39.4). These can be used in continuous or pulse modes with contact or noncontact handpieces. However, it should be understood that these wavelengths are not well absorbed by soft tissues (although pigmented tissue will absorb it the most), the use of this laser wavelength would lead to very limited effects on surface tissue and very deep, poorly controlled, and undesirable tissue penetration. This is bypassed by using a material on the tip of the fber that absorbs these wavelengths (either pigmented material such as ink paper or a suitable crystal material) and creates a red hot thermal tip, which is then used in surgery. In reality, the laser wavelength produced is not actually used for surgery; it is only absorbed by the fber tip to essentially produce a thermal cautery. Although diodes are cheap and easy to use due to their fberoptic contact tip, this thermal cautery effect rather than the use of the actual laser beam is very ineffcient for surgery and severely limits its use by the OMS [19].

### **39.4 Applications of Lasers in Oral and Maxillofacial Surgery**

Three basic categories of application of lasers in OMS can be classifed as follows:


**Fig. 39.5** Focused vs. defocused beam

Incisional procedures require a precise thin cut with careful control of the depth of the cut. The thickness or thinness of the cut with a laser is controlled by the spot size (usually 0.1–0.4 mm). The laser beam's focal length is usually between 1 mm and 1 cm, depending on the delivery system, and is where the smallest spot size can be achieved with maximum power density. This is called "focused mode" (Fig. 39.5). The laser can be controlled by a foot pedal, but it is often useful to limit time on tissue to speeds faster than a foot control allows. Hence, a "gated/pulsed mode" can be used to generate 2–20 pulses per second to create or mark a dotted outline with lesser depth and allow careful delineation of the margins of the excision. This is then followed by a continuous mode (using the foot pedal) to "connect the dots" and complete the excision. The settings to obtain a desired depth of cut vary from one tissue to another due their different water content and absorption coupled with the surgeoncontrolled factors as mentioned earlier. It is not possible to have standard laser parameters for all types of tissues or lesions. The smallest spot size possible with 4–10 W power can be a good initial setting. The initial cut then gives the surgeon ability to observe the clinical effect and depth of incision, which then can be used to lead to adjustments of the power and time on target to achieve the desired changes. Common soft-tissue lesions that can be incised or excised using lasers include fbromas, mucoceles, epulis fssuratum, mucosal or gingival lesions, papillomas, etc. Wound closure after a laser-assisted incisional biopsy or excisional procedure is often unnecessary due to the limited scarring and excellent hemostasis and is up to the surgeon's discretion, as healing is excellent regardless of closure. Closure does not usually effect hemostasis or pain relief (Fig. 39.6a–c) [5].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 39.6** (**a**) Lesion of tongue. (**b**) Tongue after laser excision with no closure. (**c**) Excellent healing

Ablative or vaporization procedures are done when the surgeon wants to remove only a superfcial layer of the tissue. Lasers, cryotherapy, chemical peeling, and scalpel can be used for this purpose, but the precision of cut and control of the depth of tissue changes along with excellent hemostasis make lasers the preferred tool for vaporization procedures. Lasers, when used for vaporization procedures, are used defocused so as to decrease the power density (the energy per unit area) and limit the depth of effect while increasing the area of the tissue ablation. The spot size used for vaporization ranges from 1.5 to 3 mm and allows large surface areas to be removed very superfcially (literally cell layers at a time if desired). This is ideal for large but fat and superfcial lesions such as hyperkeratosis, dysplasia, lichen planus, etc. The laser is again used in gated mode to carefully and precisely outline the margins. This is followed by passing the laser in overlapping "U"-shaped patterns to cover the entire area. The parameters can be adjusted by the surgeon, just as in incision cases, after the frst pass is done at 4–10 W power. As implied by vaporization, there is no tissue available for biopsy in these cases. Hence, a defnitive diagnosis should be established prior to performing ablative or vaporization procedures on mucosal lesions (Fig. 39.7a–c).

Due to the ability of CO2 lasers to constrict blood vessels rather than coagulate blood, it can be an excellent tool to obtain hemostasis in most surgical wounds where the vessels are smaller than the thermal effect of the laser in tissue (about 500 μ). The lateral thermal effect of the laser beam should be equal to or greater than the diameter of the bleeding vessels. If the vessel is of larger diameter, conventional hemostatic techniques should be used. For small superfcial vascular lesions, the CO2 laser can be used to excise the lesion (since the feeding vessels are usually smaller than 500 μ), while deeper or larger vascular lesions are best treated using lasers that are specifcally absorbed by hemoglobin, leading to true coagulation of the lesion itself [6].

#### **39.5 Specifc Examples of Application of Lasers in Oral and Maxillofacial Surgery**

#### 1. *Cosmetic facial surgery:*

The use of lasers in cosmetic surgery has changed these procedures signifcantly over the years. The advantages of lasers as previously described, including the capability of lasers to only affect the superfcial layers of skin with precise depth control, turned out to be its critical advantage. Lasers in cosmetic facial surgery can be used both for incisional or ablation procedures based on indication [20].

Lasers used for laser skin resurfacing (removal of superfcial skin wrinkles from the face) are an example of ablation or vaporization procedure. In skin resurfacing procedures, the superfcial layers of the epidermis and

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 39.7** (**a**) Hyperkeratosis of lateral tongue. (**b**) Laser ablation of tongue. (**c**) Healing after laser ablation

papillary dermis are removed while leaving behind the reticular layer of the dermis with its adnexal structures. This layer, if intact, provides epithelial cells that are required for rapid re-epithelialization of skin in a uniform

©Association of Oral and Maxillofacial Surgeons of India

#### **Fig. 39.8** Laser cosmetic skin resurfacing of face

manner. As opposed to chemical peels or dermabrasion, lasers offer more precise depth control, which is crucial in uniform healing and improved outcomes. CO2 and the Er:YAG are the commonly used lasers for skin resurfacing, although recent improvements in the way CO2 is used to improve results with lessened postoperative healing time, have severely diminished the use of the Er:YAG. Although the CO2 laser is most commonly used and is more effective, it can be associated with long-term erythema and greater risk of scarring if exposure is done too deeply. Since CO2 is a continuous-wave beam, which means that even at a short "pulse" the laser would be on tissue too long and lead to scarring, it must be electronically "pseudopulsed" at high powers to obtain the short times needed to reduce risk from lateral thermal damage to the unintended underlying dermis (roughly less than 1000 μs). On the contrary, the Er:YAG laser has less penetration in skin owing to its higher affnity to water in tissue. It is also a true pulsed laser and hence it allows higher power with shorter pulse duration. Although this is an advantage of Er:YAG laser, which helps reduce risk of excessive ablation and scarring, as mentioned before, it also decreases the effectiveness and results of the Er:YAG laser and most surgeons have abandoned its use in favor of newer CO2 lasers that create very deep but thin vertical columns in the skin, allowing for tissue contraction with quick healing and less chance of scarring [21].

In skin resurfacing, as opposed to ablation of intraoral mucosal pathology, the passes of laser should not be overlapping to avoid excessive tissue ablation (Fig. 39.8). Computer pattern generator handpieces (CPG) can be used, which automatically create a uniform pattern of coverage on the skin (Fig. 39.9a, b) [22].

Skin resurfacing principles are also used in scar revision procedures. The prominence or visibility of a scar is mainly affected by the surface depression or elevation. The CO2 and Er:YAG lasers can be used to reduce the elevation of the scar tissue or decrease the elevation of the surrounding skin to make a depressed scar tissue blend well with it (Fig. 39.10a–c). Healing scars can also have hypervascularity as evidence by prolonged erythema. This can be managed by decreasing the vascularity within the scar by use of vascular-specifc lasers such as 532-nm KTP:YAG or Pulsed Dye Lasers (PDL) lasers [23].

In blepharoplasty, the CO2 laser can be used to make a transconjunctival incision on the lower eyelid as well as the skin incision for the upper eyelid blepharoplasty. The use of laser to then excise muscle or fat with excellent hemostasis provides great visualization and tissue control (Fig. 39.11).

In endoscopic brow lift techniques, lasers are passed through either fexible fberoptic cables or through small diameter hollow waveguide extensions in order to be used for incisions made within the optic cavity. The advantage of using lasers in endoscopic procedures is to provide precise incisions with excellent hemostasis, which aids in better visualization. Laser is used to incise the periosteum and/or muscle attachments. CO2 laser is a commonly used laser for this purpose.

#### 2. *Intraoral mucosal surgery:*

Lasers have been extensively used in intraoral mucosal surgeries. Common applications include incisional/excisional biopsy of intraoral soft-tissue lesions (Fig. 39.12a– c), frenectomy (Fig. 39.13a, b), ablation of premalignant lesions, preprosthetic procedures such as vestibuloplasty and excision of epulis fssuratum (Fig. 39.14a–d). As mentioned previously in this chapter, advantages of lasers stand superior compared to traditional scalpels in terms of wound healing, tissue handling, and hemostasis, which ultimately help improve patient experience when used for intraoral procedures as well. Vaporization or ablation of tissues intraorally is usually performed on premalignant lesions, commonly for white lesions such as hyperkeratosis or mild epithelial dysplasia. More severe dysplasias are best excised with the laser to allow for margin control. Defnitive diagnosis with the help of a biopsy is a precursor for management of premalignant lesions with laser vaporization since there will be no specimen to biopsy [24].

Although diode, ND:YAG, Er:YAG and CO2 lasers can be used for intraoral mucosal surgeries CO2 lasers stand out as the workhorse and most studied laser over the

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 39.9** (**a**) Computerized pattern generator (CPG) for laser skin resurfacing. (**b**) Optional patterns for CPG

past four decades. When using lasers intraorally on intended soft tissues, care must be exercised to protect adjacent hard/soft tissue from inadvertent damage or devitalization due to pulpal damage. This is done with either a moist gauze, a mouth guard, a wet tongue blade, or nonrefective plastic instrumentation [25]. The use of lasers as compared to scalpel is presumed to also provide a decreased chance for lymphatic and hematogenous seeding as an added advantage in the management of premalignant or malignant lesions. Principles and technique of incision and ablation have been detailed elsewhere in the chapter.

#### 3. *Implant surgery:*

Lasers are also useful in the management of periimplant soft tissues. 10,600-nm wavelength CO2 laser and 980-nm diode are the commonly used soft-tissue lasers in implant surgery. ND:YAG laser, due to its inherent high depth of penetration and risk for damage to adjacent tissue and implant surface, is considered unsafe for use on implants. Er:YAG laser, which has been approved for use on hard tissues, has been used in uncovering a thin layer of bone in second-stage implant uncovering and initiating the implant osteotomy, but there is need for further data on the use of Er:YAG for complete preparation of implant osteotomy. 9300-nm CO2 laser has been used for hardtissue applications, but more data on its safety and effcacy are needed. Advantages of using lasers in implant surgery include the precision, atraumatic tissue handling, bloodless feld of view, and decreased bacterial contamination. Lasers have been used for several indications in implant surgery, including implant site preparation procedures such as the release of frenal attachment, excision of redundant tissue, and incision placement prior to bony osteotomy. Placement of incisions with lasers as opposed to scalpel creates less infammation, swelling, and postoperative discomfort to the patient as well as added property of tissue sterilization from antibacterial effect. They can also be used for second-stage surgery, including removal of soft tissue and, in the case of Erbium lasers and 9300 nm CO2 lasers, bone covering the implant [26].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 39.10** (**a**) Depressed scar of face. (**b**) Blending of scar using CO2 laser. (**c**) Results of laser scar revision

Treatment of mucositis and peri-implantitis around implants is a challenging problem in implant surgery with limited effcacy when managed via conventional treatment protocols. If an implant with signs of peri-implanti-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 39.11** Laser blepharoplasty

tis is deemed stable without severe bone loss and/or mobility, then treatment is attempted to salvage. Treatment of choice includes debridement of the granulation tissue accompanied by the administration of antibiotics around the implant for the eradication of as much bacteria as possible followed by bone graft of any defect created. Traditional tools include plastic instruments, citric acid, chlorhexidine, and topical Tetracycline. A laser-assisted algorithm for management of peri-implantitis includes obtaining access to the implant in question via a laser incision and refection of fap leading to exposure of implant and surrounding bone. Then, the pathologic tissue is vaporized by laser energy and the implant surface and bony defect are decontaminated by the laser, which is accomplished by ablating the surface at low energies to kill off any bacteria on the surface as well as any attached soft tissue. Bone grafting, if necessary, can then be performed. Data have shown signifcantly better outcomes in cases of peri-implantitis as compared to conventional tools. As in other laser-assisted surgeries, healing is enhanced because of reduced infammation and decreased postoperative pain as opposed to conventional tools [26] (Fig. 39.15a, b).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 39.12** (**a**) Outlining a small tongue cancer for laser excision. (**b**) Excision of lesion with CO2 laser. (**c**) Lesion excised and allowed to heal with no closure

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 39.13** (**a**) Laser frenectomy with CO2 laser. (**b**) After laser frenectomy

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 39.14** (**a**) Epulis fssuratum of maxilla. (**b**) Excision of epulis with CO2 laser. (**c**, **d**) Supraperiosteal dissection allowed to secondary heal

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 39.15** (**a**, **b**) Implant uncovering with CO2 laser

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 39.16** TMJ arthoscopy with Holmium YAG laser

#### 4. *Temporomandibular joint surgery (TMJ):*

Arthroscopic TMJ surgeries have been proven to be effcacious, minimally invasive, and effcient procedures to treat and manage several aspects of temporomandibular joint disorders. Arthroscopic surgery utilizes various modifed cutting instruments, which are passed through a narrow trocar to be able to release the disc attachments, remove redundant infamed tissues, and/or perform synovial biopsies. These conventional cutting tools are diffcult to maneuver, increase the risk of bleeding, which creates a poor visual feld and a higher risk of complications. Use of lasers administered via narrowdiameter fberoptic cables adds advantages in maneuverability, which makes it easier to sweep through the small-sized TMJ and make precise incisions and ablation with better hemostasis in a noncontact mode. Due to their high water absorption, CO2 and Er:YAG lasers cannot be used for this purpose. Ho:YAG is the commonly used laser for the purpose of TMJ arthroscopy. With low water absorption, it is less affected by the presence of the synovial and lavage fuids, while low penetration (~0.5 mm) decreases the risk of damage to adjacent tissues. Other TMJ procedures such as disk repositioning and removal have been described with the use of arthroscopic techniques and laser assistance with signifcant success (Fig. 39.16) [17, 18].

#### **39.6 Safety Concerns with Use of Lasers**

Effcient and safe use of lasers starts with operator's familiarity with details of the laser system in use. All laser systems come with a user's manual, which lists all required technical details as well as recommended indications for use of that laser system. Common safety issues with lasers happen with accidental exposure of surrounding tissues.

#### 1. *Personnel protection:*

Patients, providers, and the assistants are all at risk of inadvertent irradiation with lasers. Any refective surface in the area of laser target can divert the beam away from the intended area and potentially cause harm. Use of special protective glasses (that are matched to the specifc wavelength of the laser) can help avoid injury to eyes of patients or personnel in the operatory. Everyone in the operatory should be familiar with the basic functioning of the laser equipment and nonrefective tools should be used and refective surfaces intraorally such as crowns be protected with a wet sponge or nonrefective retractors. Posting a "danger" sign for use of laser on the door of the operatory in order to avoid unprotected personnel from entering the room, while laser is in use could avoid accidental injuries as well (Fig. 39.17a, b) [6].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 39.17** (**a**) Wavelength-specifc eyewear for protection of operator, patient, and assistants. (**b**) "Danger" sign outside the operatory along with closure of any see-through glass panels on the door

#### 2. *Fire hazard:*

Lasers in an oxygen-rich environmental such as the oral cavity of a patient being provided supplemental oxygen, or inside an endotracheal tube, can pose a signifcant fre risk. To avoid fre, supplemental O2 concentration should be kept to a minimum required level or use of room air is recommended. For endotracheal tubes, compressed air can be substituted for oxygen to keep the inspired concentrations of oxygen to below 30% [6].

#### 3. *Laser plume:*

When a laser is used for incision or vaporization procedures, the tissue that is being handled will create a "plume," which consists of potentially hazardous particulate debris, which is considered infectious. There are studies, which showed the presence of viral DNA in the plume, but to date there hasn't been any clinical signifcance or transmission proven. Nevertheless, for protection of the provider/staff, high fow suction made of a nonrefective material such as plastic should be used to remove the plume. Wearing masks and other personal protective barriers such as eyeglasses will help avoid infection transmission as well [27–29].

#### **39.7 Conclusion**

Lasers have changed the OMS practice signifcantly to a point that it is today an essential surgical tool in many ways. Development of lasers in future may overcome current disadvantages and increase utility and safety. Use of lasers in hard tissue is still somewhat limited in comparison to softtissue applications. Further research and development could help improve this aspect of laser.DisclosureAuthors have no fnancial conficts to disclose.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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**40**

## **Piezosurgery in Oral and Maxillofacial Surgery**

Shravan Renapurkar and Sowjanya Nagamalla

#### **40.1 Introduction**

The term "piezo" has been derived from the word "Piezien," which implies pressure in the Greek language. Piezoelectric effect was frst described by Jacques and Pierre Curie in 1880 and involves the appearance of an electric charge across certain crystals when they are under mechanical pressure. Inversely, when an electric current is applied across them, they deform. This phenomenon of deformation when under alternating current creates microvibrations or oscillations of ultrasonic frequency [1]. Although ultrasonic microvibration technology was experimentally used earlier, it was in 1988 that Italian oral surgeon Tomaso Vercellotti developed the frst commercially available Mectron® piezoelectric bone surgery unit to cut bone tissue while minimizing the limitations of conventional tools [2, 3]. The frst use of piezoelectric surgery was for osteotomies by oral and maxillofacial surgeons and later on used for neurosurgical and orthopedic procedures. This revolutionary tool not only lowers the chance of damage to adjacent vital soft-tissue structures such as nerves and vessels during osteotomies, but also preserves osteocytes, which in turn complements bone healing [4, 5].

#### **40.2 Equipment and Principles of Use**

Piezoelectric surgery devices are generally small portable units comprising a handpiece with a working tip and a foot control switch, which are connected to the main powergenerating unit. The main power unit also features holders for the handpiece and irrigating/cooling fuid (Fig. 40.1a–c). The handpiece is the critical part of this device, containing within it the ceramic chips where the microvibrations are created and later transmitted to the working tip. Commonly

Commonwealth University Medical Center, Richmond, VA, USA e-mail: srenapurkar@vcu.edu; nagamallas@vcu.edu

used ceramic chips in Piezoelectric surgery units are Barium Titanate or an equivalent material. The amount of deformation in the crystals within the handpiece and resultant vibrations in the insert depend on the power applied [6].

The working tips of a piezoelectric system used for surgical purposes are interchangeable inserts, which can be of different shapes, sizes, and cutting edges based on the intended clinical applications. These inserts can be made of different materials and be coated with titanium or a diamond layer to improve the cutting effciency. To create a cutting effect rather than a debriding effect, the vibrations of the insert enter into a resonance with the ceramic chips, which increases the energy output. This, combined with the form of the insert, acts like a micrometric oscillating saw. The main energy unit has an interactive touchpad, which allows the operator to control the frequency of vibrations, power of the unit, and the amount of irrigating or coolant fuid. The pressure applied on the insert can also be manually controlled by the operator and can affect the frequency delivered to the target tissue, which in turn affects the cutting effciency. When higher pressure is applied at the tip, it impedes the cutting effciency of the insert and releases the energy as heat, which is detrimental to the bone as well as adjacent soft tissue [6, 7].

The Piezoelectric unit also allows for election of modes of operation, which are preset power modes with varying frequencies to match the clinical application. The frequency is usually set between 25 and 29 kHz, which can create microoscillations of 60–210 μm amplitude, providing the handpiece with power exceeding 5 W. The vibrations produced in the "Low mode" result from average ultrasonic powers, without frequency overmodulation, and allow the operator to perform endodontic procedures. On the contrary side, the "high mode" and the "boosted mode" are characterized by vibrations with higher ultrasonic power and frequency overmodulation, which allows cutting of mineralized tissue. The "boosted mode" has frequency overmodulation with an increased rate that is most effcient for osteotomy and osteoplasties in surgical procedures, while the "high mode" is less

S. Renapurkar (\*) · S. Nagamalla

Department of Oral and Maxillofacial Surgery, Virginia

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 831

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_40

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 40.1** (**a**) The Piezosurgery® unit from Mectron® is made of a power supply unit, a handpiece, its holder, an irrigant solution holder, foot control switch. (**b**, **c**) Inserts or working tips of a piezosurgery unit. (**b**) shows working tips for Sinus lift and (**c**) shows osteotomy tips

effcient but more helpful in periodontal procedures and bone smoothening [6–8].

The device includes an irrigating system for cooling that creates an adjustable jet of coolant solution through a peristaltic pump at rates between 0 and 60 ml/min and helps remove debris from the cut surface and helps maintain hemostasis because of its cavitation effect. This enhances visibility, particularly in diffcult-to-reach anatomical zones, by scattering coolant liquid as an aerosol. The irrigation liquid should be refrigerated at 4 °C for effectual cooling [6, 8, 9].

For optimal use and maximum effciency, the operator could select the proper power based on the surgical tissue, apply light pressure with the tip, and adjust the rate of delivery of the irrigating solution to avoid overheating the tissue and decrease the chance of damage to soft tissues. Although the device has a safe frequency range along with the cooling irrigation liquid, there is a possibility of damage to soft tissues due to high pressure and overheating [10].

#### **40.3 Advantages**

Used in many therapeutic surgical procedures, piezosurgery has several advantages when compared to traditional methods of surgical instrumentation used for osteotomies or osteoplasty. These are as follows:


#### **40.4 Disadvantages/Limitations**

Although piezosurgery has numerous advantages as listed here, it is associated with some drawbacks as follows:

• *Low effciency/increased operating time*: One of the major drawbacks with ultrasonic/piezo surgery osteotomes is the increased time required for the procedure. The cutting effciency of a piezosurgery device has been reported to be 3–4 times less than that of conventional osteotomes for some procedures [12, 13]. For example, in a randomized prospective crossover clinical study done by Stefano Sivolella, piezoelectric osteotomy of a lower third molar took 9.4 min longer than rotary tools to complete [14].


#### **40.5 Applications for Piezosurgery**

#### **40.5.1 Dentoalveolar Procedures**

Piezosurgery can be applied toward multiple dentoalveolar procedures where there is a requirement for meticulous bone preparation, atraumatic tooth extraction/exposure, and when the location of the surgical site is in proximity to vital anatomical structures. Example of applications in dentoalveolar surgery include ankylotic tooth root extraction, impacted third molar extraction, surgical exposure of impacted teeth, and extractions in patients with a thin periodontal biotype. In all of these indications, piezosurgery has the potential to limit bone loss and maximize maintenance of alveolar bone integrity, especially when the alveolar bone is thin and the procedure requires a high degree of precision. A split-mouth design, randomized, clinical trial conducted by Mantovani et al. studied differences in postoperative pain, orofacial swelling and duration of the procedure when using a rotary bur for third molar ostectomy versus a piezosurgery device. They found that, although the duration of the procedure was longer, the postoperative pain and swelling were less in the piezosurgery group [16].

#### **40.5.2 Dental Implant Surgery**

#### **40.5.2.1 Sinus Floor Elevation**

Perforation of the Schneiderian membrane during lateral wall osteotomy, and/or while raising the maxillary sinus foor manually, is a common complication, which can affect the bone grafting procedure. Use of piezosurgery in sinus lift procedures not only minimizes the chance of perforation during osteotomy but also eases the separation of the membrane as well (Fig. 40.2a–c). In the commonly used lateral approach technique for sinus lift, piezoelectric devices have a superior action in each technique or step compared to traditional instruments. The chance of membrane perforation with conventional techniques is reported to be 14–56%, while studies on the use of piezosurgery devices report it to be 5–7% [8, 17, 18].


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 40.2** (**a**) Piezosurgery insert used to perform outline of the lateral wall osteotomy to thin the wall. (**b**) Blunt piezosurgery insert used to infracture the window wall and initiate the separation of the schneiderian membrane from the sinus wall. (**c**) After the lateral sinus wall osteotomy completed, membrane separation initiated a third insert shaped as an elevator used to continue the separation of the membrane to create required space for the bone graft for augmentation

anatomy with decreased chance of membrane perforation.

• Sinus membrane separation: Most commercially available piezosurgery devices have special inserts that make the separation around the perimeter of bony window easier and decrease chance of tear or perforation during the manual lifting process.

#### **40.5.2.2 Implant Site Preparation**

Implant site healing and ultimate osseointegration of implants is negatively infuenced by the high temperatures created during site preparation. Results of an in vitro study done by Heinemann et al. in 2012 on porcine jaws comparing piezosurgery, Sonicfex®, and rotary instruments showed the highest temperature rise with use of piezosurgery, although the trabecular bone and osteocytes were still intact [19]. On the contrary, a recent randomized, controlled clinical trial by Da Silva Neto et al. in 2014 compared implant stability at various times postoperatively in osteotomies performed by conventional rotary instruments versus piezosurgery devices, and found implant stability to be higher with Piezosurgery [20]. The use of piezoelectric devices facilitates the use of selective enlargement of only one socket wall and Vercellotti called this: "differential ultrasonic socket preparation." [4].

#### **40.5.2.3 Alveolar Ridge Splitting**

Ridge-splitting techniques for alveolar augmentation is indicated when there is adequate height of bone for implant placement but inadequate ridge thickness. The conventional ridge-splitting procedure uses chisels, rotary instruments, or saws, all of which have a high risk for damage to soft tissue, undesired propagation of the osteotomy and bone fracture, as well as prolonging treatment time due to the need for secondstage surgery to place the implants. (Fig. 40.3a, b) With use of piezosurgery, one can decrease the chance of the damage to adjacent structures during the osteotomy as well as reduce the risk of bone thermonecrosis, while simultaneously providing better control of propagation of the ridge split osteotomy. Although ridge splitting was traditionally used in the maxillary arch, piezoelectric bone surgery allows ridge expansion even in highly mineralized tissues like the mandible with ease [21, 22]. Blus et al. conducted a study on ridge splitting for more than 200 implants placed in 57 patients and reported 96.5% success rate with a 36-month follow up [23].

#### **40.5.2.4 Lateralization of the Inferior Alveolar Nerve**

In order to place implants in atrophic edentulous mandibles, IAN lateralization can be used as an alternative to bone augmentation procedures (Fig. 40.4a–c). Bovi, in 2005, frst reported a technique for IAN mobilization with simultaneous implant placement utilizing a piezoelectric device. He reported that IAN mobilization with a piezoelectric device minimizes the risk of irreversible damage to the IAN and enables the surgeon to make a smaller bony window, which, in turn, decreases overstretching of the mental nerve [24]. In an in vitro study, Metzger compared transposition of the IAN with use of a piezoelectric device versus conventional burs. His study also supported the lower rate of nerve injury from use of piezosurgery [25].

#### **40.5.3 Bone Graft Harvesting**

For bone augmentation, bone grafts in the form of chips or blocks can be used. Bone chips are primarily indicated in guided bone regeneration where the stabilization of the graft is not an issue, such as multiwalled defects. On the other hand, when the bony defect is large or stabilization is diff-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 40.3** (**a**, **b**) Ridge split technique with piezo surgery. Bony osteotomies performed with piezoelectric device then ridge expanded to desired dimensions. From: Tarun Kumar, A., Triveni, B., Priyadharshini, M., & Mehta, G. (2016). Staged Ridge Split Procedure in the Management of Horizontal Ridge Defciency Utilizing Piezosurgery. *Journal of Maxillofacial and Oral Surgery, 15*(4), 542–546 (Springer)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 40.4** (**a**–**c**) Inferior alveolar nerve (IAN) lateralization for placement of implant

cult, block grafts must be utilized to augment vertical or horizontal dimension. Piezosurgery is used for harvesting all types of bone grafts, including autologous free block grafts, microvascular free faps, and bone chips.

For example, piezosurgery is commonly used to harvest mandibular ramus block grafts. This requires use of two types of piezosurgery inserts. One is the standard saw-shaped right angle insert, which is used in an area, which can be viewed directly to make the depth cut and vertical cuts, while a second, dual-angled, insert is used specifcally to make the inferior horizontal bone cut. In bone graft harvesting, piezosurgery allows better visibility, precise cuts, and good adaptation of the grafts along with better survival of bone cells. In a study by Happe in 2007 on 40 patients, bone grafts harvested from the mandibular ramus by piezosurgery resulted in 93% uneventfully healed donor sites and 96% uneventfully healed graft sites [26]. There was also minimal resorption of the graft. Shaping of block grafts can be better controlled with piezosurgery, although this can take longer than rotary instruments. In microvascular free bone faps harvested with piezosurgery, the surgeon can decrease the chance of injury to the vascular bundle along the surface of bone. With the use of piezoelectric surgery, the clinician can cautiously osteotomize the fbula or other bone without any periosteal/pedicle dissection. In addition, the piezoelectric method also allows shaping and handling the pedicle while it is still attached to the donor site.

#### **40.5.4 Orthognathic Surgery**

Piezoelectric devices are increasingly being used in orthognathic surgery due to its precise cutting and lower risk of damage to adjacent teeth and nerves. Landes et al. performed a large study on 90 patients in whom orthognathic surgery was performed with piezosurgery. This study demonstrated decreased blood loss compared to conventional surgery but no signifcant difference in surgical times. Lefort I osteotomy only required the use of chisels in about 33% of cases [5, 27, 28]. In the same study, among patients who underwent bilateral sagittal split osteotomy (BSSO), inferior alveolar nerve sensitivity at 3-month follow up was retained in 98% of the cases, compared with 84% after conventional BSSO (Fig. 40.5). When performing surgically assisted rapid maxillary expansion (SARME), the advantage of using piezoelectric surgery is that it minimizes potential damage to the descending palatine artery while separating the pterygomaxillary junction, the nasopalatine artery while making the midline maxillary cut, and it lowers indirect thermal damage to the bony surfaces and adjacent structures, including teeth [29].

#### **40.5.5 Aesthetic Facial Surgery**

Conventionally, chisels are used for osteotomy of the lateral nasal bone during rhinoplasty, which transmit signifcant force to the surrounding soft tissues in a blind manner, and increases the risk for bleeding from injury to the adjacent vasculature. A study done by Robiony et al. assessed use of chisels versus piezosurgery and found a decreased risk of injury to adjacent soft tissues with use of piezosurgery. Use of chisels also may create inaccuracy due to blind use and the unguarded nature of the instrument. On the other hand, use of piezo will not incur this issue and gives the operator more control and accuracy [30].

#### **40.5.6 Distraction Osteogenesis**

Distraction osteogenesis (DO) is indicated when there is a need for signifcant amounts of bone augmentation or lengthening, or when the soft tissues that cover the bone will not

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**Fig. 40.5** (**a**, **b**) Orthognathic surgery using Piezo. Figure shows steps in a BSSO. Variations in the blade design can be used based on desired osteotomy

allow for osseous augmentation. The use of piezosurgery permits the initial osteotomy to be made delicately and accurately while minimizing injury to the soft-tissue fap and surrounding hard tissue, allowing maintenance of the vascularity needed for successful new bone formation [31]. Distraction Osteogenesis (DO) can be used for distraction of either the alveolar bone or the basal jawbone. DO with a piezoelectric device ensures the preservation of original bone structures, specifcally the cancellous bone, which favors the healing process due to its high healing potential. In a recent article, DO with microdistractors using a piezoelectric device has shown favorable results in patients with Pierre Robin Sequence [32].

#### **40.5.7 Temporomandibular Joint Surgeries**

Osteotomies and osteoplasty in the temporomandibular joint (TMJ) region involves risk to the facial nerve as well as major vessels such as the internal maxillary artery and the masseteric artery. Due to anatomical complexity, the use of conventional bone-cutting tools such as burs and saws may put these vital structures at risk of injury or permanent damage. Given the advantages of piezosurgery as discussed previously in the chapter, its use in this specialized surgery is reasonable and advisable. In 2014, Anson Jose observed less bleeding along with minimal postoperative complications while treating TMJ ankylosis with piezosurgery [33].

#### **40.5.8 Inferior Alveolar Nerve Preservation**

The IAN is at risk whenever there is the need to extract impacted mandibular molars, enucleate large cysts, or remove benign mandibular tumors. In 2009, Dr. Kagan Degerliyurt presented an article describing a procedure called the "bone lid technique," which is performed by using a piezosurgery device when there is a defnitive risk of damage to IAN [34, 35].

#### **40.5.9 Trauma**

Piezoelectric devices can be used for reconstruction in multiple trauma cases, such as comminuted frontal bar fractures, to cut and shape the inner table of a calvarial bone graft, to osteotomize a healing fracture while reducing the chance of adjacent tissue injury. Using piezosurgery in post-traumatic cases can help preserve bone, protect adjacent soft tissues, decrease blood loss, improve visibility, and ensure a better overall outcome [36].

#### **40.6 Conclusion**

Piezosurgery is a promising surgical tool for safe and effective use in various surgeries. For an oral and maxillofacial surgeon, piezosurgery allows safer and effective osteotomy or osteoplasty compared to conventional rotating instruments such as burs and saw blades, even in complex anatomical areas. Over the past decade, it has not only been increasingly used in OMFS but has been adapted for use in neurosurgery, orthopedic surgery, and otorhinolaryngology. In addition to the surgical advantages, it helps the patient by reducing procedural stress, postoperative swelling, pain and overall improves the surgical experience. The major drawback of piezosurgery is the lack of effciency or cutting speed, which can be balanced by improved clinical outcomes. Future generations of ultrasonic devices may bring about better effciency and ultimately replace all conventional cutting tools.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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**41**

## **Computer-Assisted Navigation Surgery in Oral and Maxillofacial Surgery**

Shintaro Sukegawa and Takahiro Kanno

#### **41.1 Introduction**

The anatomy of the oral and facial region is complex, having many vital organs and structures, including an intricate network of blood vessels and nerves as well as the brain, eyes, nose, and vital teeth. Plain radiography can be used for screening because of its simplicity, but it cannot characterize detailed anatomical relationships. Currently, imaging diagnosis must be performed with computed tomography (CT) and/or magnetic resonance imaging (MRI) before surgery to characterize the surgical area and surrounding anatomical structures. Recent developments in imaging technology have allowed for rapid processing and visualization of signifcant amounts of data yielded from a variety of digital imaging modalities. Prerequisites have been established for threedimensional (3D) visualization as well as programs for the computer-assisted 3D planning of surgical procedures, and these image sources are now available to assist the surgeon in the operating room [1].

Today, surgeons can use computer-aided design and computer-aided modeling (CAD/CAM) software to assist with the planning and implementation of complex maxillofacial surgical procedures [2]. CAD/CAM software allows the clinician to import two-dimensional (2D) CT data in DICOM format (Digital Imaging and Communications in Medicine) to a computer workstation and create accurate 3D representations of the facial skeleton and related soft tissues. The data can then be used either to print a stereolithographic (STL) model or for virtual manipulation of the generated 3D model by segmentation, refection (mirroring), insertion, or repositioning of 3D objects for treatment planning [3].

Stereolithographic 3D models are useful for maxillomandibular reconstruction indicators such as


Not only are they useful in visualizing and planning, but also for providing haptic support to the surgeon for perceived excellent tactile feedback during virtual surgery. They also prove to be very useful in creating a more predictable workfow for the intended surgical intervention. Unfortunately, there is no single prediction method where the surgical plan as performed on the model can be directly transferred to the patient.

Computer-assisted surgery (CAS) uses data from image processing, and can be divided into two major categories:


Computer-assisted presurgical planning involves preoperative surgical simulation using physical or virtual 3D images or models, and helps the surgeon to appreciate the underlying skeletal anatomy in a more precise manner. The application of preoperative surgical simulations is being used in the feld of dental implantology for determining the appropriate positions and sizes of implants as well as evalu-

S. Sukegawa

Division of Oral and Maxillofacial Surgery, Kagawa Prefectural Central Hospital, Takamatsu, Kagawa, Japan

T. Kanno (\*)

Department of Oral and Maxillofacial Surgery, Shimane University Faculty of Medicine, Izumo, Shimane, Japan e-mail: tkanno@med.shimane-u.ac.jp

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 841

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_41

ating and planning for bone augmentation when needed, and in the feld orthognathic surgery for assessing the amount and direction of movement of the jaws.

The process of intraoperative navigation was developed to improve the sequence of "diagnosis-surgical planningsurgery," allowing surgeons to accurately visualize the positions of surgical instruments and guides in real time on a display of patient CT and/or MRI data. Intraoperative navigation systems integrate diagnostic imaging with the actual surgical feld, allowing simultaneous visualization of the surgical site and the analogous image counterpart with the help of a sensor that enables more precise access and manipulation for areas with sensitive anatomy. These navigation systems have now evolved greatly to minimize invasiveness while improving accuracy. The development of intraoperative navigation surgery has enabled improvement in execution and predictability for greater precision during oral-maxillofacial surgery.

This section presents an overview of currently available navigation systems and their applications, focusing on clinical utility and solutions they offer for problems and challenges in the feld of oral and maxillofacial surgery.

#### **41.2 Medical Navigation Technology**

"Navigation-assisted surgery" is a broad term and can be interpreted in various ways.

Besides these questions, navigation-assisted surgery may also be used as an "information center" to provide surgeons with accurate and effciently retrievable information. Navigation systems used for surgery are very similar to a global positioning system (GPS), as is commonly found in automobiles.

It comprises three principal components: (1) a localizer, which is analogous to a satellite; (2) a "hand-held" probe, which corresponds to the track waves emitted by the GPS unit; and (3) the CT scan data of the patient, which is analogous to a road map.

Intraoperative navigation systems were initially developed for use in neurosurgery, but they are now commonly used in surgery of the craniomaxillofacial region due to their high accuracy and reliability [1, 4] (Fig. 41.1).

**Fig. 41.1** Components of a surgical navigation system. A surgical navigation system is comparable to a global positioning system (GPS) as is commonly used in automobiles, and is composed of three primary components: a localizer, which is analogous to a satellite in space; an instrument or surgical probe, which represents the track waves emitted by the GPS unit in the vehicle; and a CT scan data set, which is analogous to a road map

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#### **41.2.1 Diferences Between Optical and Electromagnetic Tracking Systems**

Two main technologies are currently available for intraoperative navigation, including optical and electromagnetic (Fig. 41.2), and they share the same function. However, they use very different technologies to relay position information to the surgeon. Two major components of the optical navigation system are measured using an infrared camera. These include the position of the reference frame, which is the optical point of reference for navigation and is also called the patient tracker, and a surgical probe with light refectors. This enables the position of the surgical probe to be displayed on the CT or MRI image in real time. Care should be taken to ensure that both the tracker and the probe are detected by the infrared camera of the navigation system to track the instrument position within the surgical feld [5]. By contrast, the electromagnetic system utilizes electromagnetic felds and reference points on a patient borne device, along with a wired instrument for the surgeon to manipulate within the surgical feld. The system functions by creating a magnetic feld of known intensity and then using microsensors in key instruments to allow the system to determine where the instrument is located relative to the patient's anatomy [6]. In contrast to an optical system, an electromagnetic system does not require a clear line of vision between the IR camera and the sensors, allowing equipment and objects to be placed between the sensors and the IR camera. However, the accuracy of this system is compromised when using ferromagnetic instruments.

#### **41.2.2 Registration Techniques**

Registration is the task of obtaining the mutual transformation matrix by calculating the relationship between the coordinates of the actual patient space and the coordinates of the medical image. In other words, this procedure involves the alignment of the patient and the image, and it is the most important process when performing surgical navigation.

Registration techniques are categorized into two major types: (1) marker-based [7] and (2) markerfree [8] (Fig. 41.3).

In the marker-based technique, registration requires identifable markers to be placed within preoperative images that can be easily detected on the patient during the surgery. These markers include dental splints [9], skin adhesive reference markers, and bone-implanted screws [10]. In contrast, the marker-free technique is based on the patient's regional anatomy. This can be performed by registering easily identifable soft tissue or bony structures on the patient's preoperative scans. Another technique for marker-free registration is laser surface scanning, which is used to match random points on the surface of facial skin to corresponding points on CT or MRI images. More recently, hybrid registration combining methods have been used that combine point registration and surface registration [11].

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**Fig. 41.2** There are two main types of navigation systems currently available: (**a**) optical and (**b**) electromagnetic systems

844

©Association of Oral and Maxillofacial Surgeons of India

Marker-based registration Marker-free registration

**Fig. 41.3** Registration techniques for navigation preparation can be categorized into two main groups: marker-based and marker-free. Marker-based registration requires markers that are apparent on preoperative images and that are easily detectable on the patient during the procedure, such as (**a**) skin adhesive reference markers or (**b**) a referencing dental splint (**c**) Marker-free registration relies on the patient's craniomaxillofacial anatomy. Laser surface scanning is applied in a distinct marker-free registration technique, where random points on the facial skin surface are matched to corresponding points on the soft tissues in preoperative computed tomography/magnetic resonance imaging (CT/MRI) images

#### **41.2.3 Application to Oral-Maxillofacial Surgery**

#### **41.2.3.1 Application to the Maxilla and Midface**

The use of navigation systems signifcantly improves the degree of intraoperative precision and accuracy that can be predictably transferred from the planning stages to the actual surgery. However, navigational accuracy is limited by the type of system used, the method of procuring imaging data, and the intraoperative synchronization of the imaging data with the patient's actual position. The systems currently in use for maxillary and midface surgery are relatively reliable, as most have been modifed from their neurosurgical counterparts [12]. Because the maxilla and midface are immovable, unlike the mandible, the position of the skull relative to the reference is stable, and the registration procedure directly refects this. Therefore, navigation-assisted surgery is the best option at the maxilla and midface.

#### **41.2.3.2 Application to the Mandible**

The use of navigation systems is not currently approved for mandibular surgery. This is due to the nature of the mandible to move on its joint (Fig. 41.4), resulting in the registration not being refected accurately in the navigation of the mandible. However, it may be possible if the position of the mandible is held identical to its intraoperative position during image acquisition.

At present, solutions exist for the application of navigation systems to mandibular surgery. One such option is the use of a dynamic reference frame mounted to the mandible that enables the continuous tracking of mandibular movement during surgery [13]. This method utilizes a sensor frame and mandible/teeth supported markers for the direct tracking of the mandible during surgery. This permits free intraoperative movement of the mandible. The second option is to maintain an immobile intercuspation position, such as using a maxillamandibular fxation to maintain intraoperative synchronization [14]. Unfortunately, this is impossible to achieve in most intraoral procedures. Therefore, a third strategy has been developed in which the mandible is placed in a reproducible position against the maxilla using an occlusal splint. This method appears to produce no additional error.

#### **41.3 Clinical Signifcance in Oral and Maxillofacial Surgery**

There are numerous clinical applications for CAS and intraoperative navigation in oral and maxillofacial surgery. This is reiterated by literature support available over the last decade supporting its use.

#### **41.3.1 Application for Oral-Maxillofacial Trauma**

Computer-based surgery is a rapidly emerging approach used in some surgical disciplines, and can be used both as a research tool and to improve healthcare. Computer-based surgery, in combination with the use of a navigation system, has been shown to reduce overall operation time in complex anatomic areas, such as maxillofacial trauma surgery (e.g., orbital trauma reconstruction surgery), making surgery more reliable. Using 3D models based on CAS is suitable for preoperative preparation of reconstruction material for bone defects caused by trauma. On the other hand, navigation surgery is most suitable for intraoperative anatomical evaluation [15]. By combining these techniques, safer and minimally

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 41.4** The positional relationship between the reference and the target becomes unstable due to the free mobility of the mandible. If the mandible were maintained in an identical position during image acquisition and the surgical procedure, then all structures within the image could be fxed in an identical position, thereby ensuring the accuracy of the navigation surgery

invasive surgery is possible. Maxillofacial trauma may be an important indicator suggesting the use of navigation systems (Figs. 41.5, 41.6, 41.7 and 41.8). Unilateral midfacial and orbital trauma surgery may also be indicators, and are normally treated with open reduction and fxation with navigation assistance.

The largest sample sizes for navigation surgery were found in the feld of craniomaxillofacial trauma, offering signifcant positive results for orbital fracture treatment through navigation-assisted surgery. Midfacial trauma, and particularly unilateral midfacial trauma, was most common example of maxillofacial trauma available in the literature. Some of these reports described the treatment of patients with delayed zygomatic fractures requiring osteotomies to reposition the abnormally healed bones. This results in added complexity for the surgeon due to the lack of known anatomical landmarks. He et al. presented a protocol for the creation of artifcial landmarks on the surface of the zygoma [16]. The technique involved the registration being performed with rigidly fxed, light-refecting spheres placed on the patient's skull. Subsequent soft tissue surface scanning was performed using a laser pointer to complete the process.

Another challenging facet of oral and maxillofacial surgery is the management of orbital fractures. This can prove to be demanding even for the most experienced of surgeons. Literature indicates that intraoperative navigation is a very useful tool in post-traumatic orbital reconstruction. Another rising trend is the use of patient-specifc implants (PSIs). A recently published literature also discusses the use of PSIs with navigation guidance [17]. A control group was treated with navigation using prebent titanium mesh. Several signifcant factors were reported favoring the study group. PSIs are poised to make a signifcant change in the management of orbital trauma.

Innovations such as intraoperative navigation and computer-assisted surgical planning have been shown to improve the effcacy, accuracy, and predictability of surgical procedures. The 3D reconstruction abilities of software could be used to virtually display the patient's anatomy throughout the case, allowing for stereotactic navigation. During the surgery, the intraoperative navigation system helps surgeons to control the positions of implants or of repositioned bone, and assists in verifying the fnal location. A navigation system enhances the surgeon's ability to measure the extent of resection and to confrm the orientation of bone grafts used for reconstruction. Using this approach, it is possible to minimize the human error factor by increasing the adherence to a pre-

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**Fig. 41.5** A 17-year-old male undergoing a large orbital foor to medial orbital fracture reconstruction. Surgeons frst created a threedimensional model that was mirrored by CAS, and determined the angle and form of reconstruction material using third-generation bioactive/bioresorbable materials, the SuperFIXORB-MX® (OsteotransMS®) system; TEIJIN Medical Technologies Co., Ltd, Osaka, Japan, according to the shape of the orbits to be reconstructed

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 41.6** (**a**–**h**) A 17-year-old male undergoing a large orbital foor to medial orbital fracture reconstruction. Navigation will determine the exact intraoperative anatomical form. Reconstruction material before CAS was positioned at the reconstruction site. We then confrmed the exact position of the reconstruction material and reconstructed the orbital shape using the navigation system

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 41.7** (**a**) The bioresorbable mesh plate was positioned to support the orbital globe. (**b**) The reconstructed site was confrmed to match the mirror image using a tip pointer with a navigation system. (**c**) Intraoperative navigation system screenshot showing a multiplane view of the position of the surgeon's navigation probe in relation to the orbital foor defect region at the time of localization. (**d**) Shows the reconstruction plan image, created using the mirroring technique

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**Fig. 41.8** (**a**, **b**) A 33-year-old male undergoing a nasoorbitoethmoidal (NOE) and maxillary fractures open treatment, including a large orbital foor to medial orbital walls fractures reconstruction. We, maxillofacial surgeons, frst created a three-dimensional (3D) precise preorbit to orbital groove model that was mirrored by computer-assisted simulation, and determined the anatomical form of reconstruction for autogenous bone harvested from calvaria using Piezosurgery® according to the 3D shape of the orbits to be reconstructed (produced by Yasojima Proceed Co., Ltd. Osaka, Japan). Navigation will determine the exact intraoperative 3D anatomical form. (**c**) The fractured deep medial orbital wall was precisely reduced under an endoscopic-assisted navigation-guided surgery by otorhinolaryngology-head and neck surgeons. (**d**, **e**) We then reconstructed the large orbital foor and confrmed the exact position of the autogenous calvarial bone for accurate reconstruction of the orbit using the navigation system, followed by fxation using titanium screws. (**f**) The use of intraoperative CT in the hybrid operation room can provide rapid CT data during surgery for the fnal 3D confrmation of complex orbital reconstruction cases

operative plan. Furthermore, this also helps in reducing the incidence of postoperative complications due to improperly positioned or oriented bone grafts, plates, or fxation screws. Virtual surgical planning (VSP) combined with 3D printing technology has improved surgical effciency and precision through the generation of 3D surgical models, implants, and guides [18]. This increases the number of indicators suggesting the use of VSP by the surgeon, as it offers additional tools in preoperative planning and intraoperative decision making. Both VSP and 3D models may be used to plan the optimal reconstruction material in terms of the volume, shape, and dimensions required. They can also be used to produce templates for resective surgery to accurately demarcate the boundaries for resection and/or to plan more effcient and accurate reconstructive strategies. A further advantage of using 3D models is a reduction in total operative time and the elimination of potential complications from prolonged surgery.

#### **41.3.2 Application for Oral-Maxillofacial Tumor/Cancer**

Computer-assisted navigational surgery is a proven method for reducing operating time and increasing reliability in complex surgical procedures of the infratemporal fossa and the periorbital region [19] (Fig. 41.9). Navigation-assisted surgery was introduced in the feld of oral, head, and neck tumors more than 20 years ago. The use of navigation in the management of benign and malignant lesions is discussed later.

Malignant lesions of the head and neck have a high rate of recurrence (25–48%). Tumor control essentially depends on the extent of the tumor, its location, and the margins of resection, with the latter being a very important prognostic factor in cancer surgery. Feichtinger et al. [20] used navigation systems to evaluate the resection margins in the treatment of six patients with carcinomas in the nasal cavity, maxillary sinus, and oral cavity. In four patients, further resection had to be performed after an assessment with a navigation system

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**Fig. 41.9** A 79-year-old male with recurrent ameloblastoma of maxilla-infratemporal fossa. Because of the complexity of the local anatomy, tumors in the infratemporal fossa present a challenge to oral and maxillofacial surgeons. Recurrent malignant tumors in this area are particularly diffcult to resect because scars from previous operations may dislocate important structures. A navigation technique has been introduced to resect infratemporal fossa tumors and was successfully applied for the resection of recurrent malignant tumors. The visible navigation during surgery could increase the accuracy and safety of the operations and enhance surgeon confdence

using positron emission tomography (PET)-CT scans proved the initial resection to be unsatisfactory. This demonstrates that navigation surgery based on PET-CT image fusion is an excellent tool for improving the local control of advanced head and neck cancer.

Navigation-assisted surgery has also been successfully used in the management of benign tumors of the maxillofacial region [21]. This was performed with features such as mirroring and side-to-side comparisons, and was applied with successful results. Use of customized hydroxy-apatite prosthesis with pre-embedded titanium implants was used for reconstruction. Optimal positioning is secured using navigation. Some interesting techniques for reconstruction are discussed now.

It is important to remember that navigation is an excellent tool when it comes to its use in the skull base [22], the midface [23], and the neck [24]. However, its use in mandibular tumors is limited due to the possibility of changes in the spatial orientation of the lower jaw, as described earlier.

#### **41.3.3 Application for Orthognathic Surgery**

The primary determinants of success in orthognathic surgery include an accurate diagnosis, meticulous treatment planning, and the ability to transfer the plan precisely to the patient intraoperatively. In earlier years, this was performed by a process of model surgery in a laboratory using articulators on plaster casts, which were then transferred to the patient using acrylic splints during the surgical procedure (Figs. 41.10 and 41.11). The procedure was error prone at multiple levels within the sequence. Literature reports an error of up to 5 mm using this type of treatment sequence. With the advent and routine usage of CAD/CAM technology

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 41.10** Optimal treatment planning and preparation using 3D models. CAS for cleft lip and palate-related severe maxillary hypoplasia deformity patients using maxillary distraction osteogenesis. (**a**–**c**) A 17 year old male undergoing maxillary distraction for cleft-related midfacial retrusion. (**d**) Detailed computer simulation for maxillary distraction surgery in a patient with severe maxillary hypoplasia deformity was used to determine the optimal treatment plan, such as the distraction direction and degree of advancement. (**e**, **f**) A 3D printed skeletal model was used to prepare for a maxillary semi-custom-made distractor setting with fabrication

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 41.11** A 17-year-old male undergoing maxillary distraction for cleft-related midfacial retrusion. (**a**–**d**) Accurate transfer of the treatment plan to the patient in the operating room was acheived. Using the navigation system, precise placement of the maxillary distraction planned pre-

operatively at the set position was performed. The surgeon then confrmed the same distraction direction that was preoperatively planned by the intraoperative navigation. (**e**–**g**) Shows the radiographs during and post treatment. (**h**) Shows the fnal post surgical result of the patient

and virtual surgical planning, the workfow of treatment planning in orthognathic surgery has undergone a paradigm shift. The conventional workfow of model surgery and splint fabrications is slowly paving the way for VSP and custom printed 3D splints and guides.

Although the degree of inaccuracies associated with treatment planning is reduced using this approach, certain drawbacks such as autorotation of the mandible and lack of control on the vertical position of the maxilla are still prevalent.

There are three methods by which CAS is used in the practice of orthognathic surgery: (1) using real-time intraoperative guidance with surgical navigation for the repositioning of the maxilla and mandible; (2) use of 3D printed cutting guides for precise osteotomy and repositioning, with or without customized 3D printed osteosynthesis plates; and (3) the use of wafer-less surgical planning where the printed implant doubles as both a cutting guide for the osteotomy and as the fxation devices. Many clinical studies have evaluated the effcacy of these methods with promising results.

Mazzoni et al. were the frst to report the use of intraoperative navigation in orthognathic surgery, in 2010 [25]. They calculated the overlap error to assess the accuracy of the technique after surface matching the virtually planned model and the postoperative CT scan. The accuracy was reported for the entire facial skeleton, rather than for each component individually (maxilla, mandible, chin), with a mean match error for each patient ranging from 0.28 to 1.99 mm. Repeatability (<2 mm) in the face area ranged from 77.5% to 96.2% between patients, with a mean reproducibility of 86.5%.

Zinser et al. published a clinical controlled trial study in 2013 that compared the navigation technique with conventional technique, using 3D surgical guides and intermaxillary splints [26]. The highest accuracy for transfer of the maxillary plan to the patient was observed when a 3D surgical guide was used, and no signifcant linear differences between the planned virtual model and the postoperative results were present in any direction. The navigation technique only showed a signifcant mean linear difference in the vertical dimension, and differences in angulation were not signifcant in either group. In contrast, signifcant linear differences were shown for the classic intermaxillary splints between the planning results and the actual results in the sagittal and vertical dimensions. Differences in plane angulations when using an interocclusal splint were also signifcant. The usefulness of navigation-assisted surgery for orthognathic surgery was supported based on previous reports.

Published literature demonstrates that all studies have met the 2-mm success criterion, which refers to a maximum difference of 2 mm between the virtual planning performed and the actual surgical outcome. Zinser et al. reported the only prospective controlled clinical trial comparing CAD-CAM splints, navigation surgery, and intermaxillary splints for the transfer of maxillary planning [26]. The CAD-CAM splints, patented by the authors, were used for maintaining the mandibular condyles (TMJ) in their centric relation. Mandibular positioning still poses a challenge during orthognathic surgery, with none of the solutions having attained "goldstandard" status.

An important clinical limitation for the use of navigation is the increase in operating time [27]. Though there is ample support for increased accuracy levels with the use of navigation, the prolonged operating time still remains a deterrent for the routine use of intraoperative navigation in orthognathic surgery. A recent study indicates that dynamic navigation systems have an entry error of approximately 0.4 mm [28] and an angular deviation error of approximately 4° [29]. Further technological developments can be expected in the feld of orthognathic surgery, and an appropriate update for surgeons is required.

#### **41.3.4 Application for Preimplant Bone Augmentation/Dental Implants**

Loss of teeth and supporting structures is a common occurrence in the feld of oral and maxillofacial surgery for patients who have suffered extensive alveolar bone defects caused by cysts, tumors, facial trauma, or severe periodontal disease [30]. Comprehensive reconstruction methods, including rehabilitation with multiple dental implants, are commonly required to restore function in these patients.

Issues like atrophic jaws, where dental implants cannot be placed due to the loss of bone corpus, are managed by regenerative procedures. Although bone augmentation at the mandibular posterior area is important for occlusion reconstruction using dental implants, it is diffcult due to anatomical limitations arising from the inferior alveolar nerve (IAN) and the mandibular bone. However, bone augmentation at the mandibular posterior area can be performed safely and reliably using CAS with 3D modeling and navigation systems (Figs. 41.12 and 41.13).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 41.12** (**a**–**d**) Computer simulation based on preoperative CT data will determine the bone augmentation method for implantation. In this case, we chose bone augmentation using the sandwich technique. The necessary bone augmentation volume and position of the anatomically

important inferior alveolar nerve (IAN) were confrmed using computer simulation. Based on this information, we will determine a safe bone cutting line. Surgeons then created a surgical guide using a 3D model based on simulation

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 41.13** (**a**–**d**) This is a continuation of Fig. 41.12. While confrming the position of the IAN in real time based on intraoperative navigation, the surgeon cut the alveolar bone with reference to the surgical guide created before surgery. (**e**) The surgeon then inserted autologous

bone taken from the donor and increased the alveolar bone vertically. The most important goal in this surgery is to acquire alveolar bone height as planned before surgery. (**f**) The bone height can be confrmed in real time based on intraoperative navigation

Traditionally, implants have been placed freehand or with the use of laboratory-fabricated guidance stents. The use of CT-guided 3D printed stents with coordinated drill sequencing has minimized errors to a level of less than 2 mm for crestal and apical deviations, and to less than 5° in angulations. Dynamic navigation systems use a time-effective method to accurately place implants with equivalent implant placement error. Currently the Image-Guided Implantology system (Navident; HERMANS Corp., Tokyo, Japan) is the only dynamic image navigation system (DINS) available for in-offce dental procedures in Japan. Its counterpart in the United States is the passive optical dynamic navigation in implantology (X-Nav Technologies, Inc., Lansdale, PA, USA).

Navigation in dental implantology can add the following advantages: (1) precise depth control and reduced risk of IAN damage [31]; (2) help in planning for fapless surgery or limited fap elevation surgery with reduced postoperative morbidity [32]; and (3) accurate spacing and implant angulation compared to using a freehand approach.

The use of virtual implant planning and intraoperative navigation allows for prosthodontic and surgical coordination due to its planning accuracy and implementation in actual surgical scenarios.

Dynamic navigation methods have similar advantages, including high accuracy, time- and cost-effectiveness, minimally invasive techniques, and fexibility in changing the implant size, system, and location during the surgical procedure [33]. An additional advantage is comfort provided the surgeon in the form of posture, facilitating reduced bending of the neck and back. For example, dynamic navigation allows implant placement for patients with a limited mouth opening, or requiring an implant at a second molar site with reduced access, by relying on a navigation screen to guide the drill sequence without direct visualization of the patient's mouth.

#### **41.3.5 Clinical Applications for the Removal of Foreign Bodies**

Retrieval of foreign bodies in the craniomaxillofacial region is often extremely dangerous due to the proximity to various vital structures within a limited anatomical space [34]. This may be made more complex by the presence of deep foreign bodies secondary to severe trauma such as gunshot wounds or blast injuries, which signifcantly alter the anatomy. Precise location of the foreign body is the frst step in the retrieval process, and this may be accomplished with preoperative scans and 3D image rendering. The intraoperative step is next, and is more challenging, as the exact location of the foreign body within the surgical feld must be ascertained. Traditional methods utilize a stereotactic "double needle" method with venipuncture needles for triangulation

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 41.14** (**a**–**g**) A 65-year-old female with a foreign body due to dental instrument breakage in the mandible, occurring during an endodontic treatment for a restorative dental procedure. (**a**, **b**) Fracture of root canal instruments, with a fractured piece protruding beyond the apex, is a troublesome incident during endodontic treatment. Locating and retrieving these objects represents a challenge for maxillofacial surgeons because they are diffcult to access due to the proximity between the foreign body and vital structures. Using the navigation system for mandible treatment is diffcult as the mobile nature of the mandible complicates its synchronization with the preoperative imaging data during surgery. (**c**) The broken dental instrument was removed using a

of the foreign body using plain radiographs [35]. This involved the two reference needles being sequentially placed until both met the foreign body on radiographs. Through blunt dissection, one of the needles is made to contact the foreign body and locate it. It is important to understand that it may be diffcult to distinguish small changes in position on plain radiographs. The use of C-arm digital fuoroscopy was a signifcant advancement for this method, providing rapid radiography [36]. However, as with plain flms, fuoroscopic images are 2D, which imposes limitations when locating

minimally invasive approach with a surgical navigation system and an interocclusal splint for stable, identically repeatable positioning of the mandible. (**d**, **e**) Based on the 3D position of the navigation probe, a location that best approximated and the most anterior extent of the fragment was selected. (**f**) A minimal vestibular incision was made at this location, a subperiosteal refection was performed, and the foreign body location was confrmed using the navigation system. (**g**) The instrument was carefully visualized and extruded from the apical to the tooth crown side and was then removed using mosquito forceps through the medullary cavity of the crown side of the tooth

objects in a 3D space. The use of intraoperative ultrasound imaging has also been proposed to localize foreign bodies. However, the precision involved in positioning may be questionable, and its use in the oral cavity may also be limited by the size of the instrument.

Intraoperative navigation systems could allow a foreign body to be accurately located in 3D space; these systems are very effective for removing a foreign body during facial surgery [37] (Figs. 41.14 and 41.15). One limitation of navigation is the incapability of the system to account for

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 41.15** A 78-year-old female with a small foreign body in the maxilla. Accurate determination of the position of the foreign body in the maxillofacial region can be challenging. This may be due to a smallsized foreign body or a limited infammatory response. Navigation systems are helpful in identifying the location of the foreign body, determining the optimal approach, and performing the surgical proce-

dure using a minimally invasive surgical strategy. In this case, registration could be reliably performed before surgery using an optical navigation system that facilitates the process, utilizing splints with embedded reference points. This method can decrease the operation time

intraoperative soft-tissue changes. The use of navigation techniques superfcial tissues or to minimize soft-tissue manipulation may help us overcome this to an extent.

#### **41.3.6 Application for Dentoalveolar Surgery**

Dynamic computer-based image navigation technology is a good method for increasing accuracy while minimizing the invasiveness of surgery. It has the additional advantage of real-time access to intraoperative radiographs, which enable us to perform complex dentoalveolar procedures with relative ease. Currently, the Image-Guided Implantology system (Navident; HERMANS Corp.) is the only dynamic image navigation system (DINS) available for in-office dental procedures in Japan. This is an ultraviolet-based optical system, which was approved by the US Food and Drug Administration for the placement of dental implants. However, its use for other dentoalveolar procedures is not approved. Its advantages in the field of dental implantology have already been discussed earlier. The use of dynamic navigation when applied to complex dentoalveolar procedures, such as the surgical removal of third molars, is similar to its use for dental implants, helping the surgeon prevent inadvertent damage to key structures like the IAN, roots of adjacent teeth, or the lingual plate of the mandible [38]. Common indications for the use of navigation in dentoalveolar surgery include third molar extractions and the location and extraction of supernumerary [39] or malposed teeth (Fig. 41.16), as well as teeth, which get iatrogenically displaced into the sinus, the sublingual pouch, or even the infra temporal fossa.

The use of CAS in oral and maxillofacial surgery has been enhanced with the increasing availability of CBCT. This in turn has promoted the use of Dynamic Image Navigation. As described earlier, the use of DINS during surgical extraction improves visualization of the regional anatomy, preventing or minimizing complications secondary to dentoalveolar surgery. In addition, improved instrument control allows for reduced bone removal, minimization of the surgical access size, and an overall reduction in the morbidity of the procedure. As discussed earlier, this technology also allows for improvement of the ergonomics involved during the surgery. Lastly, dynamic guidance can serve as an effective teaching tool for young surgeons by displaying the surgery and the locations of vital structures on screen.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 41.16** (**a**–**i**) A 24-year-old female with an impacted maxillary canine tooth. Bone lid surgery involves cutting a window into the cortical bone and removing a portion thereof; this portion is subsequently returned to its original position at the end of surgery. Bone lid surgery is a minimally invasive technique designed to avoid secondary large bone defects during osteotomies. However, because jaw bone lesions are completely covered with cortical bone, it can be diffcult to accurately determine the position of the lesion from the outside. As a potential solution, we used navigation-assisted bone lid surgery. Using navigation, surgeons could confrm the state of the impacted tooth and surrounding tissue from above the covered bone. We were also able to establish a safe and reliable bone cutting line. In addition, the removed cortical bone was returned to the same (i.e., presurgical) position. Navigation-assisted bone lid surgery for the removal of impacted teeth increases surgical accuracy, minimizes invasion, and allows the bone to be returned to its original position (**a**, **b**)-pre operative OPG and CT (**c**–**e**)-shows intra operative navigation. (**f**) outline of canine marked (**g**, **h**) impacted canine being removed (**i**) the bone lid placed back in position

Wang reported the following advantages of surgical navigation in complicated extractions: (1) localization of teeth for accurate access planning and minimal bone removal; (2) differentiation of impacted teeth from erupting tooth germs; (3) ensured transfer of the preoperative plan to the surgical procedure; and (4) the marking of safety margins while preserving adjacent structures, to avoid complications [40].

### **41.3.7 Application for Temporomandibular Joint and Skull Base Surgery**

The TMJ and surrounding anatomy, including the skull base, are extremely complex and require a cautious approach during surgery. Intraoperative navigation can play an important role for surgeries such as the removal of an ankylotic bony mass, tumor resection, and gap arthroplasty [41]. Successful treatment outcomes have been reported by studies for the use of navigation assistance in unilateral surgery for the TMJ. Other publications report that navigation is helpful and increases safety in TMJ surgery. A recent publication used navigation to compare prospectively treated groups of patients with recurrent malignant tumors of the infratemporal fossa. Although the results are not independently signifcant, they yielded a beneft to the navigation cohort. The authors concluded that surgeon confdence and safety during the operations improved, but the navigation system alone did not determine patient outcomes.

Management of tumors at the skull base or of end-stage degenerative TMJ disorders requires thorough knowledge of the regional anatomy and precise 3D planning of the resection margins with attention of vital structures in the immediate vicinity (Fig. 41.17). The location, invasion, and extent of the tumor are key determinants in deciding the surgical approach. In the past, malignant tumors that had infltrated into the infratemporal fossa or the middle of the skull base were considered inoperable due to the compromised access and inability to achieve predictable tumor control or hemostasis.

The use of surgical navigation for skull base surgery offers the following advantages: (1) ensuring safer and quicker skull base access through a dynamic display of the precise operating site and the extent of bone drilling, thereby signifcantly reducing intraoperative risk; (2) mapping the anatomical structures and important landmarks such as the foramen ovale and rotundum; and (3) the incorporation of allied imaging modalities, such as 3D CT angiography and MRI, into the intraoperative navigation planning, increasing our understanding of the skull base anatomy and the internal carotid artery region.

As surgery of the skull base is not affected by the shifting brain, use of navigation in this feld is more precise than in other neurosurgical procedures. The use of a navigation system for the resection of tumors of the skull base or of TMJ lesions increases surgical predictability while reducing the surgical duration.

#### **41.3.8 Other Applications**

Another application of intraoperative navigation is in surgery for the management of Eagle's syndrome, which may be due to the elongation of the styloid process of calcifcation of the stylomandibular ligament [42]. This condition involves a group of symptoms, including throat pain and foreign body sensation on the affected side, refex otalgia, head and neck pain, and hypersalivation. Surgical treatment was indicated for patients with no symptomatic improvement following conservative treatment.

The surgery may be performed by two different approaches: (1) transcervical and (2) transoral. The cervical approach provides better surgical exposure of the area, but has the major disadvantage of an external incision. The transoral approach is cosmetically favorable, and is more commonly used. However, this approach offers very limited access. This may affect the management of intraoperative complications, including hemorrhage or diffculty in identifying the styloid process. Several methods have been advocated recently to overcome these problems. One report suggests an endoscopically assisted transoral approach for achieving better exposure and visibility of the feld. Another method proposes a combination of piezoelectric surgery and surgical navigation for a transcervical approach to remove the styloid. This technique offers a safe and effective method for the treatment of Eagle's syndrome (Fig. 41.18).

#### **41.4 Recent Advances**

#### **41.4.1 Navigation Using Intraoperatively Updated Images**

The accuracy of surgical navigation in recent years has been augmented by the induction of intraoperative imaging modalities like the intraoperative CBCT, C-arm, and O-arm systems [43]. These offer intraoperative multiplanar reconstruction capabilities, which enable the improvement of surgical outcomes in demanding surgeries such as surgery of the orbital walls. Furthermore, the popularization of hybrid operating rooms (Fig. 41.19) equipped with both intraoperative imaging and navigation systems has revolutionized surgery of the maxillofacial region. It is now possible to continuously update intraoperative images to determine the best sequence to follow during surgeries (Fig. 41.20). The effectiveness of a navigation system using intraoperative CT images has been already demonstrated in orthopedic surgery and maxillofacial operations, which involve bone movement, such as trauma surgery and orthognathic surgery. Intraoperative CT images have allowed for rapid intraoperative evaluations, which when coupled with surgical navigation, may allow for performing more complicated maxillofacial surgery with increased accuracy.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 41.17** A 70-year-old female with temporomandibular joint (TMJ) ankylosis. Ankylosis surgery is used for gap arthroplasty and mobilization of the joints. (**a**–**c**) However, removal of the bony ankylosis and creation of a gap between the ramus of the mandible and the base of the skull can be diffcult because of the size of the ankylosis and the anatomy on the inner aspect of the mandible. Virtual planning is useful in conjunction with surgical navigation to remove the ankylosis. (**d**) First, a computer simulation based on preoperative CT data was performed for the virtual surgery. (**e**, **f**) Once the virtual surgery was completed, templates were constructed using rapid prototyping techniques from the virtual plan and applied at the time of surgery to facilitate the bony cuts. (**g**, **h**) Using the intraoperative navigation system, the surgeon can see the medial aspect of the mandible on the navigation station CT and protect important structures on the medial side. (**i**–**l**) This visualization prevents signifcant bleeding from the vessels on the medial side of the mandible and prevents penetration into the middle cranial fossa during release of the ankylosis. The temporalis fap was used for prevention of reankylosis

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 41.18** (**a**, **b**) A 45-year-old male with elongated styloid process syndrome (Eagle's syndrome). A minimally invasive approach with an intraoperative navigation system was used. (**c**) Preoperative preparation involved a custom interocclusal splint to produce the mouth opening conditions required during surgery. In this case, since the transoral approach was employed, it was important to reproduce the same mouthopening conditions when obtaining the preoperative images required during surgery, because the position of the styloid process and the blood vessels may change depending on the position of the mandible during the mouth opening. Since it is diffcult to implement the locational fndings from the preoperative imaging data while performing surgery owing to the mobile nature of the mandible, a custom interocclusal splint for repeated maximum opening in the same mandibular position,

#### **41.4.2 Wearable Mount Display for Navigation-Assisted Surgery**

Although intraoperative navigation yields helpful information on anatomical features, it is used in conjunction while enabling surgical access, was used. (**d**) The patient was taken to the operating room, where the custom interocclusal splint was reinserted. (**e**) To perform patient-to-CT and MRI data registration, the instrumentation navigation probe was used to trace the reference array and soft tissue landmarks of the face. (**f**) Using the 3D position of the navigation probe, the location of the elongated styloid process was identifed. (**g**, **h**) After confrmation of the resection location via the transoral approach, the styloid process was dissected using piezoelectric surgery. Follow-up examination showed an uneventful recovery with no associated complications. (The resection of the styloid process using an intraoperative navigation system and a custom interocclusal splint during a transoral approach, together with a piezoelectric cutting device, is safe and effective for the treatment of Eagle's syndrome)

with a monitor. Generally, the direction of the monitor from the surgeon and operator is different from that the surgical field. Therefore, to see the navigation image, the surgeon and the operator must look up, which is stressful for the operator. It is important to minimize muscle tension and allow the surgeon to perform the operation in a

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 41.19** A hybrid operating room is a surgical theater equipped with advanced medical imaging devices, such as fxed C-arm and angiographic systems. Intraoperative CT imaging is convenient because the

CT is installed in the hybrid operating room. Furthermore, recent advances in technology have made it possible to edit and use images simultaneously with intraoperative CT imaging

relaxed position. Moving the head to look at the monitor can result in considerable misalignment of the eye-handtarget axis during task execution, significantly affecting postural comfort and interventional safety. In recent years, head-mounted display monitors have been developed to address this problem. Such wearable displays can provide high-quality images [44]. Using a head-mounted display monitor, surgeons can finish the surgery without moving their head to check the navigation image. The head-mounted device also allows both the surgeon and the assistant to view both the navigation image and the surgical field without interrupting the flow of surgery. This contributes to rapid surgical operation, resulting in minimally invasive surgery. Navigation-assisted surgery with a head-mounted display is a revolutionary technique. In the future, head-mounted displays will be wearable devices that promote the use of navigation (Fig. 41.21).

#### **41.5 Conclusions and Perspectives**

CAS and navigation offers signifcant improvements in patient orientation and safety in every facet of maxillofacial surgery. Ranging from precisely planned orthognathic procedures to the removal of foreign bodies requiring

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 41.20** (**a**) A 19-year-old male with a complex facial fracture and orbital fracture. Navigation surgery is diffcult to apply for treating a complex facial fracture with orbital fracture. (**b**) Since reconstruction of the buttress of the facial bone is performed prior to the treatment of the orbital fracture, preoperative CT data and the actual state of the facial bone are different. Therefore, a navigation system using preoperative

extremely fexible surgical options, and from minimally invasive dental implantology procedures to radical tumor resections of the skull base, they have made their mark improving procedure safety, predictability, and accuracy of surgery while also improving options for intraoperative adaptations. In the future, the application of CAS is expected to further reduce operative risks and surgery CT data cannot be employed. (**c**) Using CT data obtained after facial fracture reduction, (**d**) it is possible to use a navigation system refecting the updated patient condition. The use of CT in the hybrid room can provide rapid CT data during surgery. (**e**) The orbital foor defect has been repaired. (**f**) Post operative CT showing the accurate reduction of fractures

time, accompanied by a considerable decrease in patient stress.

Navigation systems are effective for delicate and accurate oral and maxillofacial surgery and neurosurgery, as well as for otolaryngology and orthopedic surgery. In the future, we expect to develop more convenient and reliable navigation systems using new technologies and devices.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 41.21** The head-mounted display can provide high-quality images with wearable technology. The head-mounted display unit was composed of a head-mount image processor unit (HMM-3000MT; Sony Corporation, Tokyo, Japan) and a head-mounted display monitor. Although the navigation system provides helpful information, it is used in conjunction with a monitor. Generally, the direction of the monitor differs from the surgical feld. Therefore, to see the navigation image, the surgeon and the operator have to look up, which is stressful for the operator. Using a head-mounted display monitor, we could fnish surgery without moving the head position. The surgeon must perform not only the surgery but also intraoperative systemic management. Multimodality patient information is important in such cases. Multimodality medical information fusion and processing have been developed in recent years. This head-mounted display system allows the integration of preoperative radiological fndings with monitoring of navigation images and patient vital signs. Using the head-mounted display system, the surgeon can see multiple images in one view using a split screen, regardless of the head position. This technology facilitates safe surgical management with the navigation system

#### **References**


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**Part XIV**

**Practice Management in Oral and Maxillofacial Surgery**

## **Human Factors Recognition to Enhance Team Working and Safer Patient Care**

Peter A. Brennan and Rachel S. Oeppen

#### **42.1 Introduction**

Human error and organisational mistakes are a signifcant cause of morbidity for patients. It is important to recognise and address human factors (HF) in the context of our own performance optimisation, enhancing team working to improve patient safety, and better working lives for clinicians across surgery and medicine.

Medical errors are usually multi-factorial rather than the direct fault of any one individual. Organisational issues, poor team working and other HF are often at the root of many incidents and errors. The Surgical Checklist produced by the World Health Organization (WHO), and aviation-styled communication training initiatives have been advocated to optimise surgical performance by reducing human fallibility and misinterpretation between team members. Brief and debriefng processes and other performance improvement practices have been positively rated when incorporated into healthcare. Ergonomics and other factors such as stress and fatigue, emotional status, hunger, dehydration and situational awareness can all lead to human error, but these are often under-appreciated and in some cases even disregarded.

The aims of this chapter are to raise colleague awareness of both individual human factors and those relevant to organisations and to highlight relatively simple methods to actively reduce error in healthcare.

#### **42.2 The Scale of the Problem**

Over 70% of plane crashes are due to a human mistake rather than a failure of the aircraft itself. Issues with communication can occur in up to 80% of air disasters. Recognition of factors leading to human error, including tiredness, stress, and repetitive tasks, and an acceptance that a certain degree of failure is almost inevitable, has improved air safety. These factors are being increasingly recognised by healthcare professionals [1]. The American Institute of Medicine report entitled "To Err Is Human" published in 1999 and subsequent work has found death from preventable medical errors, with those in surgery second only to medication errors as the most common reasons for death from medical error [2]. Recent estimates place avoidable patient deaths in USA hospitals at over 400,000 per year, with preventable harm in the top three causes of death [3].

While the authors were not able to source any statistics for the Indian sub-continent, death in UK hospitals from medical error is estimated to be about 4000 per year, with a disproportionate amount of harm caused by errors in surgery. To put this into context, this would be the equivalent of more than one A320 fatal airbus (Fig. 42.1) crashes occurring twice a month. Incidentally, the A320 is the aircraft involved in the widespread media coverage after an emergency landing on the River Hudson in January 2009 by Captain 'Sully' Sullenerger, subsequently dramatized in the well-known movie, Sully. Despite the WHO checklist, which is widely used throughout the modern world, the number of 'never events'—those that should never happen, including wrong site surgery and retained instruments or swabs—is increasing [4]. Although doctor-induced mistakes are quite rare, a near miss occurs far more commonly in the hospital environment. An investigation and detailed cause analysis following any incident can help organisations learn, prevent and reduce the chance of such errors occurring again in the future.

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_42

**42**

P. A. Brennan (\*)

Maxillofacial Unit, Queen Alexandria Hospital, Portsmouth, UK e-mail: peter.brennan@porthosp.nhs.uk

R. S. Oeppen Consultant Radiologist, University Hospital Southampton, Southampton, UK e-mail: Rachel.oeppen@uhs.nhs.uk

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 42.1** The fight deck of an Airbus A320 being confgured for departure

#### **42.3 How Do Human Errors Arise?**

Recognition and understanding of those relevant HF involved in potential error is vital for improving patient safety. These factors include fatigue and tiredness, stress, communication style, effective team working, and good leadership. The wellknown 'Swiss cheese model' of error (Reason [5]) is illustrated in Fig. 42.2. Organisational failures contributing to medical error could include pressures on individuals to meet hospital targets, having too many patients on an operating list than is deemed safe, too many patients in an outpatient clinic, working very long hours without taking a break or being expected to operate the following day after having being disturbed overnight with on-call emergencies.

#### **42.3.1 Senior Management Support Is Essential in Helping to Reduce Medical Error**

Senior management commitment is essential in ensuring safety across any organisation. An open culture has to be key in any hospital agenda and strategy. Poor leadership together with a 'blame culture' led to more than 35 deaths in the Bristol paediatric cardiac surgery service. As a result, a large number of changes were implemented to limit future preventable surgical incidents. Pilots, aircraft ground engineers and other aviation safety staff are encouraged to actively question any safety issues related to their aeroplane, and their employer must investigate concerns, even if this means stopping a fight from taking off. In healthcare, we should be following this safety model with higher hospital management and surgical team leaders creating a safe environment

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 42.2** Schematic representation of the Swiss cheese model of human error. Each of the cheese slices acts as a barrier to an error occurring with the fnal chance for stopping the error being the elimination of the unsafe act itself. Error has its origin in organisation infuences (latent failure) and those caused by individuals and teams (active failures)

**Table 42.1** Avoiding human error traps


**Table 42.2** Take special care—recognise situations in which error/ harm is more likely


to report and action possible error. The surgical team has to endorse the use of evidence-based best practices, including use of the WHO Surgical Checklist, avoiding human error traps (Table 42.1) and early identifcation of those situations in which harm or error is more likely to occur (Table 42.2).

While a surgeon's life or limb is not at stake during an operation (unlike an air disaster when a mistake made by an airline pilot might result in the death of all those on board, including the crew), the psychological effects of a major surgical incident or error can be devastating to both individuals and teams [6].

#### **42.3.2 Human Factors That We Should Be Thinking About**

There are many personal human factors that can cause error, including tiredness and fatigue, nutritional status, anger and stress, multitasking and loss of our own situational awareness. However, all too often as individuals we sometimes imagine that these factors do not apply to us, and therefore we might choose to ignore them (such as missing lunch, working for many hours without taking a break) signifcantly raising the risk of patient harm and potentially damaging our own health and well-being.

#### **42.3.2.1 Fatigue and Tiredness**

These are known in aviation and other high-risk organisations (HROs) as signifcant factors that can cause human error. As a result, strict guidelines have been put in place in these HRO, with for example fight crews only being working a defned number of hours in any given month. Many airlines have a policy in place to make sure that one pilot is as refreshed as possible for the most dangerous aspects of fying such as the landing. Intense concentration can only be maintained for about 20–30 min. For example, one pilot will take over the actual landing when the other has done the frststage descent. The effect of these personal factors in surgical performance is less understood than in aviation though tiredness will affect decision making, as well as doing complex tasks. Situational awareness will also be affected even if surgeons behave as if they are immune and operate for many hours without taking a break. The ability for sleep deprivation to degrade performance is dramatically under-estimated by healthcare providers [7].

With reference to the Swiss cheese analogy, tiredness, emotional factors and stressful surgery can all align together to raise the risk of serious error. Table 42.2 shows some of these high-risk situations. Good communication and team working and the ability to question decisions with a phrase such as 'can I check that I've got this correct' can be useful. Other phrases like 'I am not happy' and 'I am going to take over' can also be used in situations where an error might happen.

#### **42.3.2.2 Nutritional Status and Hydration**

These factors signifcantly affect HF and our performance in a demanding operating room setting. Even modest levels of dehydration are known to impair cognitive function and performance [8]. Meals that contain protein, carbohydrates and fats such as those derived from olive oil, fsh and avocado as well as certain nuts are considered to be best for optimal nutrition. Simple sugars (such as chocolate bars) and processed food do not readily support long-term concentration and the endurance that is needed in the operating theatre [8].

The authors recommend taking a short break of 10–15 min every 2–3 h when at work, especially if performing complex tasks or surgery. Of course, the procedure can continue if there is suitable expertise within the team, but each team member should plan to take a regular break, which can be staggered. Even a short time spent away from operating can help provide a fresh outlook, improve morale, and enable a toilet and food/water break. Recovery is aided through regular sleep, which is positively linked to healthy eating and drinking. Certain nutritional supplements may also support performance [9].

#### **42.3.2.3 Stress and Emotions While We Are Working**

Emotional and psychological issues can affect performance. While these emotions can often be hidden, a trigger or socalled sentinel event that results in upset or even anger can occur, during times of high mental workload or in those stressful situations that we all will be familiar with. Many of us will have witnessed others (or ourselves) having an emotional outburst, including shouting at other team members. During these events, error is much more likely to occur. In these situations, visible anger usually results from additional hidden factors that others do not see in the so-called anger triangle (Fig. 42.3).

A simple thing to remember, **HALT** (Table 42.3), reminds us of sometimes overlooked personal issues and to ensure we stop to take a break. The importance of a short rest cannot be emphasised enough if it is safe, especially when these HALT

**Fig. 42.3** Anger triangle: many emotions may be hidden from others until a sentinel event causes an outburst of anger. During this time, error is much more likely

**Table 42.3** Try to stop or inform a member of the team when experiencing or witnessing these HALT factors


issues becomes apparent, and may prevent something serious from occurring.

Management strategies such as increasing our own emotional awareness and learning how to deal with personal stress may also be useful.

Effective communication with the rest of the team and questioning decisions where there might be some doubt by saying something like 'can I check that I have got this right?' is paramount. Other words such as 'I'm not happy' and 'I'm going to take over' can also be used in situations where potential errors are deemed more likely.

#### **42.4 What About WHO and Other Checklists and Team Working Dynamics on Surgical Performance?**

The WHO Surgical checklist has resulted in signifcant decreases to post-operative mortality and morbidity on a worldwide scale, yet errors persist and recur. While checklists, including WHO's, cannot address all aspects of medical and surgical practice, good team working with effective briefng can help to optimise team performance. There are many situations in surgery and other medical specialities when mental or physical workloads increase suddenly or dramatically (for example, during complex microvascular reconstruction) and these can have an adverse effect on performance. In such cases, team dynamics and an understanding of each individual's role within the wider team are crucial. Airlines enforce a 'sterile cockpit' policy in which noise is kept to only essential conversation below 10,000 ft (during high-risk procedures such as landing and take-off) and only essential conversation relating solely to procedure is permitted. The sterile fight deck concept is being advocated for reducing error in anaesthesia and surgery [10]. This should be discussed with all team members at the pre-operative briefng so that all know the need to stop non-essential communications at certain times. Poor team working has had tragic consequences on many occasions. In one well-known UK case (Elaine Bromiley), the airway was lost following induction of anaesthesia for a routine ENT procedure. The anaesthetists made repeated attempts to secure an airway, and had 'tunnel vision' about this rather than seeking assistance from surgeons or others for an emergency needle cricothyroidotomy.

Ancillary staff were well aware of the patient's prolonged hypoxic state but felt reluctant to assert themselves or state the need for alternative intervention. No individual took a leadership decision role and the team did not have designated roles during a diffcult airway situation. As a result, the patient died when she could so easily have been saved. Lack of leadership, poor communication, inability to challenge hierarchy, and many other HF failings were to blame for this tragedy.

Effective team working is also valuable in promoting a sense of shared responsibility for patient safety. Team performance is often improved when front line staff actively monitor important performance criteria such as blood loss, regular swab counts, and needle and instrument checks.

The WHO checklist and other team tools have helped with theatre safety; however, never events still continue to occur [4]. Much more is needed around safer team interactions. The team brief, coupled to a debriefng after the day's operating, can enhance patient care, team working and feeling valued by all.

Airline pilots discuss the 'what if?' scenario in pre-fight briefngs and know who will be doing what if something doesn't go well (Fig. 42.4). Some clinicians even go as far as to ask team members 'how could we kill this patient today?' Table 42.4 summarises items that could be included in a good briefng and debriefng. The nominated team leader can summarise what has been discussed and repeat back as necessary to confrm to everyone that there is shared understanding. We also suggest monitoring each other for signs of loss of situation awareness as well as looking for features of tiredness and fatigue.

An open culture and respect by all team members are crucial for better team working and enhancing patient safety. Even the most inexperienced pilot will question decisions of senior Captains without fear. While a hierarchal gradient between trainees and their boss is needed, this should be suffciently fat to allow and encourage them to speak up when something does not seem right. At all times, this needs to be done in an environment where there is no fear of retribution for speaking up about something that may appear trivial.

This concept is important in the team brief so that students, trainees, and nurses all feel valued. We need to be aiming for a 'smooth and enjoyable fight' in our workplaces, even if the view isn't as exciting as from the fight deck.

#### **42.5 Situational Awareness**

An important HF principle is recognising and understanding how we relate and behave and how changes over time. Surgeons can sometimes develop tunnel vision during long procedures. This can be confounded by indicators that they recognise confrm their behaviour, and thus may need to rely

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 42.4** The three key elements that comprise situational awareness (SA)

#### **Table 42.4** Things to consider at a team brief

A well-prepared team knows their role, looks out for each other and helps all to feel valued.

#### *Briefng*

Introductions, transparent culture, 'anyone can speak if concerned' Team working and leadership

Identify major parts of surgery and who is going to do what

Ask 'What am **I** going to do if something goes wrong?'

Situation awareness—how can I intervene when something doesn't seem quite right

Decision-making skills

*Debriefng*


on other team members to identify a problem. Losing track of time is one factor, which can lead to catastrophic consequences as highlighted by the Elaine Bromiley incident mentioned earlier. An otherwise competent team lost their situational awareness as critical minutes passed by during failed intubation attempts. Her husband Martin (airline pilot) knew about the same tunnel vision from a fatal plane crash, where a prolonged attempt to troubleshoot a landing light warning and a crew member's failure to assertively communicate led to the plane running out of fuel.

A lack of situation awareness causes many diving accidents. Recognising it for ourselves is important for developing surgical skill and where possible stopping what we are doing when things do not seem quite right. A well-briefed team will be able to recognise at a much earlier stage when something is not quite right [11].

A simple diagram showing the three key components of situational awareness is shown in Fig. 42.4.

#### **42.6 HF Training When Not in the Operating Theatre**

Technology developments have led surgeons to perform increasing minimally invasive procedures. Physicians also do more invasive procedures such as interventional radiology (IR), percutaneous coronary techniques and gastrointestinal endoscopic surgery. The lessons learnt from surgery and team briefs, WHO checklists and other HF training initiatives should be applied to other parts of the hospital.

Medicine is a challenging activity and patients are far more complex than aircraft. Greater control is needed wherever possible to minimise the risk of harm to others as a result of human error. HF training can readily be taught across medical practice leading to widespread improvements in safety. It is clear that any HF training includes important safety concepts, including better communication in teams, a culture of open reporting without blame, regular safety briefings and leadership skills. Aviation-based 'Crew Resource Management CRM' training has improved reduction in wrong site surgery. Hospitals need to recognise that they can infuence attitudes, culture and values towards patient safety. HF training is simple, cost-effective and deliverable way of getting all staff members involved.

#### **42.7 Conclusion**

HF and better team working, as well as commitment towards continual performance improvement, are increasingly recognised as essential aspects of patient safety. Despite this, serious medical errors have not been abolished. Many errors can be prevented by recognising and using simple measures in our clinical practice. An appreciation of those factors that affect each of us as being potential contributors to error is a great step towards improving safety for our patients.

We believe and advocate that HF training is essential for medical staff as it is for airline employees. Since the introduction of compulsory HF training in the early 1990s, there has not been a single death on a UK-based airline due to human error in more than 3 billion passenger journeys. An individual would have to fy every day for 38,000 years before experiencing a human error–related aviation catastrophe. Surely we owe it to our patients to do everything we can to improve their safety too?

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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## **De Novo Practice of Oral and Maxillofacial Surgery**

Srinivas Gosla Reddy and Avni Pandey Acharya

# **43**

#### **43.1 Introduction**

The exhilarating and exciting emotion of starting your own practice can also be a daunting experience to a freshly passed out maxillofacial surgeon. Student loans taken during the course of one's studies also play a signifcant role in determining one's ability to take on any additional fnancial burden.

As oral and Maxillofacial surgery is a bridge between medicine and dentistry, there is a continual national debate regarding the need to pursue a dual degree. The option to pursue a condensed medical degree as part of the current syllabus is still not available in India. Thus, new residents should always strive to do additional training [residency, fellowship and diplomas] in their felds of interest to expand their expertise prior to starting their own set-ups [1]. It is a well-known fact that it is easier to gain knowledge and skills during the starting of one's career rather than later in life. The goal is to aim high by keeping one's feet grounded in the soil of academics.

The fre of determination and passion should always be kept alive in order to truly succeed and excel in our feld. The truly successful surgeon is the one who has thrived against all the odds and taken advantage of every opportunity that has come his or her way. This chapter aims to guide the freshly passed out maxillofacial surgeon regarding further avenues of learning and about the establishment and expansion of one's surgical practice.

### **43.2 Professional Skill and Learning**

For the freshly passed out maxillofacial surgeon, the option of acquiring fnancial stability always appears alluring. However, it is a well-known fact that enhanced surgical skills

S. G. Reddy (\*) · A. P. Acharya

and strong academic knowledge cannot be traded for the fnancial gains obtained by prematurely starting one's surgical practice. Thus, it is always advisable to pursue additional training in the form of a fellowship, residency or diploma in one's area of interests [2, 3]. This trend will help the surgeon establish a niche practice where they specialize in a particular domain of oral and maxillofacial surgery, which eventually leads to improved surgical results and credibility for our profession. This kind of surgical practice will also help to create an edge over the plastic surgeon and the otolaryngologist and establish a distinguishable specialty offering an unequivocal service to patients. Despite the prevailing circumstances governing one's decision to enter practice immediately or continue training, everyone will eventually contribute to the OMFS feld with their skills and knowledge.

Laskin [4] made an organized attempt to tackle this problem by dividing the scope of oral and maxillofacial surgery into three categories: areas of expertise, competence, and familiarity. To be addressed as an oral and maxillofacial surgeon, one needs to include the areas of expertise and competence in their work profle.


The frst step in learning a skill is to know how a skill is learned. Educationists have constructed many models attempting to outline the learning process. The most widely accepted was frst documented by Noel Bunch and was subsequently re-worked by Abraham Maslow (Figs. 43.1 and

GSR Institute of Cranio-maxillofacial & Facial Plastic Surgery, Hyderabad, Telangana, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 871

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_43

43.2). In the beginning, a student is in the 'unconsciously incompetent' phase. An undergraduate dental student in their third year would have no idea about administering local anaesthesia. After working on the skill for some time, they move on to the 'consciously incompetent' phase. Here, they have attempted different ways of anaesthetizing teeth and are now keenly aware of the various ways to give local anaesthesia along with their shortcomings in certain regional nerve blocks.

Most of our trainees will arrive somewhere between these two steps of knowing what they can and cannot perform. Educators must help them overcome their limitations. Once they are aware of their shortcomings, they can actively

**Fig. 43.1** Gradation of maxillofacial surgery and importance of super specialization

The obstacle to a meticulous 'ability preparation' is that most of our instructors perform numerous components at an unknown and advanced skilled dimension, while the students are frequently unmindful of numerous components of what they have to learn. The individuals who have overlooked the subtleties of an expertise are entrusted with showing people who don't know about what abilities they are unequipped for performing. The initial step for an ace instructor is to perceive that the educator and understudy live at inverse fnishes of the authority. Perception, readiness, practice and tolerance are the key components of learning in any skill [6].

Hierarchy of Competence

©Association of Oral and Maxillofacial Surgeons of India

Such a great amount of training with an expertise that it has moved toward becoming "second nature" and can be performed effectively. The expertise can be performed while executing another

Comprehends or realizes how to accomplish something. Showing the expertise or information requires fixation. May be separated into steps, and there is overwhelming conscious involvement in executing the new skill

Does not comprehend or realize how to accomplish

Does not perceive the shortfall or value of the ability. Perceive their own ineptitude and estimation of the new

Does not comprehend or realize how to accomplish something, Hierarchy of Competence Recognizes the shortage, just as the estimation of another

ability intending to the shortfall.

Creation of slip-ups can be basic to the learning procedure at this stage

#### **43.2.1 Kolb's Learning Cycle** [7]

David Kolb is renowned in educational circles for his Learning Style Inventory. In Kolb's speculation, the drive for the headway of new thoughts is given by new experiences. "Learning is the technique whereby data is made through the difference in comprehension" [7]. Kolb's experiential learning style theory is conventionally addressed by a four-stage learning cycle in which the understudy contacts all of the bases (Fig. 43.3). Along these lines, everyone responds to and needs the improvement of a wide scope of learning styles.

Here are brief depictions of the four Kolb learning styles:

#### • *Diverging (feeling and watching—CE/RO)*

These individuals can take a gander at things from alternate points of view. They are touchy. They want to observe as opposed to doing, tending to accumulate data and use creative ability to tackle issues. They are best at reviewing solid circumstances from unique perspectives.

Kolb called this style 'separating' in light of the fact that these individuals perform better in circumstances that require thoughts, for instance, conceptualizing. Individuals with a wandering learning style have wide social premiums and like to assemble data.

They are keen individuals, will in general be inventive and enthusiastic, and will be solid in expressions of the human experience. Individuals with the veering style like to work in gatherings, to tune in with a receptive outlook and to get individual criticism.

• *Assimilating (watching and thinking—AC/RO)*

**Fig. 43.3** Kolb's Experiential learning cycle

The Assimilating learning inclination is for a compact, sensible methodology. These individuals require clear clarifcation as opposed to pragmatic chance. They exceed expectations at seeing wide-going data and sorting out it in a reasonable coherent confguration.

This learning style is essential for viability in data and science vocations. In formal learning circumstances, individuals with this style incline toward readings, addresses, investigating diagnostic models, and need room to thoroughly consider things.

#### • *Converging (doing and thinking—AC/AE)*

Individuals with this combining learning style can tackle issues and will utilize their fguring out ability to discover answers for reasonable issues. They lean toward specialized assignments and are less worried about individuals and relational angles.

Individuals with a combining learning style are more pulled into specialized errands and issues than social or relational issues. A meeting learning style empowers expert and innovation capacities. Individuals with a meeting style like to try different things with new thoughts, to recreate, and to work with handy applications.

#### • *Accommodating (doing and feeling—CE/AE)*

The Accommodating learning style is 'hands-on' and depends on instinct as opposed to rationale. These individuals utilize other individuals' examination and want to take a viable, experiential methodology. They are pulled in to new diffculties and encounters. They usually follow up on 'gut' nature as opposed to sensible examination.

Individuals with an obliging learning style will in general depend on others for data than complete their own examination. This learning style is common inside the all-inclusive community. To become familiar with specifc, careful abilities, an understudy needs to go intensively through every one of the styles of learning. First, we have to observe, think and feel pursued by experimentation on models to learn the aptitude to do medical procedure on humans.

#### **43.2.2 Transformative Learning Way**

Transformative learning is the procedure by which we digest and decipher data based on our own encounters to date, to deal with ace Surgical aptitudes. This can be seen in a case of a boss helping a careful student with his or her frst case. One of the key issues is for the chief to be accessible if for no other explanation other than to counsel, whenever required, and guarantee that things go easily. Grown-up students need to realize that they have the director's certainty and support and that they will be permitted to extend their range of abilities to attempt to take care of any issues they may experience, before the chief strides in.

The following enquiries of destinations and points can give understanding into the learner's self-appraisal capacity or trainee's self-assessment:


#### **43.2.3 Intra-operative Educating**


The teacher must attempt to 'dominate', if important to help the patient yet this positively doesn't imply that boss should hinder in each progression and make the student uncertain.

#### **Post-operative questioning**

This can begin to happen as the student is concluding the case; however, a few learners may discover this diverting, which may hamper their execution.

The chief should plan to question in a peaceful domain.


progressed nicely, yet on the off chance that they don't convey, the student may feel that some perspective was not progressed admirably. Strong correspondence is critical [8].

#### **43.3 Career Goals**

Oral and maxillofacial surgery gives a wide range of alternatives from a conventional private minor oral surgery practice to specialist maxillofacial surgery in trauma, temporomandibular surgeries, orthognathic surgeries, implantology, oncology, aesthetic surgery and cleft and craniofacial surgery [9]. The following are the alternatives, which can be taken by a newly passed oral and maxillofacial surgeon:


• *De novo Practice*—Opening one's own OMFS offce from the ground up is an extremely tough task that is not for the weak hearted. It has been rightly said the war feld ought not be entered without a weapon and thus one need to be confdent in their surgical skills and also have a basic understanding of the administration involved with running one's own practice [10].

#### **43.4 De Novo Practice**

#### **43.4.1 Requirements**


• *Marketing strategy*: Health care associations actualize business techniques through projects and administrations, and achievement relies upon program structure and execution. Beginning a business adventure without an arrangement is out and out welcoming a fasco and human services is no exemption for this standard. Since we are specialist co-ops, we ought to dependably remember that this feld is certifably not a "high pay" creating feld except if we are managing corporate divisions. That is the reason why practical objectives ought to be set to keep ourselves as well as other people away from the rat race of cash. This positively doesn't imply that you ought not dream about a sensible way of life.

#### **43.4.2 Types of Practice**

There are four different ways by which medical practices can be organized:


Additionally, you can work under the umbrella of some settled specialist and eventually move toward becoming a partner in the not-so-distant future [15].


#### **43.4.3 Qualities Needed**

#### **43.4.3.1 Strategic Planning**

Due to the contingent nature of the decision of essential structure be it sole owner or in affliation, Strategic arranging is required. It is a defnite methodical report demonstrating the manner in which it intends to advance from its present circumstance to the ideal future situation [16].

The SP procedure is isolated into progressive stages. The writing gives diverse names to unmistakable stages yet we are adopting established strategy, distinguishing fve values simultaneously. The Mission, Vision and Values ought to be institutionalized amid the underlying stages.


#### **43.4.3.2 Technique Formulation**

The accompanying fve phases ought to be considered

	- Resources: It incorporates individuals, monetary spending plans, consumable and non-consumable supplies and their level of obsolescence.
	- Licensure—Legal parts of drug store, radiations, and different licenses with respect to specifc region ought to be taken already relying upon the standards of the region.
	- Analysis of clinical and research work, action and spending plan ought to dependably be kept aside [16].

#### **TOWS Matrix Analysis**

The TOWS Matrix is aimed at developing strategic options from an external-internal analysis. TOWS idea is frmly identifed with SWOT investigation. Whereas SWOT Analysis starts with an internal analysis, the TOWS Matrix starts the other way around, with an external environment analysis; the threats and opportunities are examined frst. As indicated by H. Weihrich (1982) [19], Dangers, Opportunities, Weaknesses, Strengths (of the association) ought to be examined in a specifc order, as a critical thinking succession during the time spent on the procedure plan. To streamline, let's use TOWS examination in beginning an oral and maxillofacial medical procedure set-up:

Inner Strengths: The accompanying could be qualities of the endeavour:


#### Inward Weaknesses


Individual shortcomings (inside negative factors or challenge) like defcient abilities, terrible work propensities or attributes like poor relational abilities, poor systems administration, ineffectual authority characteristics, absence of specialized mastery, absence of IT information, absence of comprehension of statistical surveying, absence of promoting skill and so on because of which wrong choices are generally taken.

The following stage is the planning of TOWS 'Matrix of key' choices, which empowers determination of supportable, open door, simpler, and quantifable results. '*Inward'* are the shortcomings and qualities and '*outer'* are the dangers and shortcomings. Four quadrants with various vital circumstances are created as pursued:

*S-O*—How can the organization employ the expertise of its own professionals to respond to the needs of centres? By partnering up, the organization can convince the institutions that there is enough capacity, knowledge and experience to train young people to independent professionals at all levels of surgery.

• *SO circumstance*—*maxi-maxi system.* This circumstance compares to the maxi-maxi methodology whereby it is conceivable to have solid extension and broadened advancement. In such cases, if the cost is utilized as to prepare individuals and keep them on minimal effort at frst to give complete consideration by the prime specialist will prompt bringing down of beginning costs. Along these lines, more income is produced amid starting days just to have the capacity to rise as market pioneer.

*S-T*—How can the organization use its skilled staff to compete with cheaper workers employed by competitors? A smart approach for the organization would be to communicate to the outside world that their staff has accredited diplomas and that it's important for health care centres to comply with legal requirements and safety standards.

• *ST circumstance*—*maxi-little system*. The wellspring of troubles in development and improvement are ominous outer conditions (predominance of dangers) like a lot of swarming of good oral specialists in the zone, or patients paying limit is low, and so on. The procedure should utilize vast interior qualities in endeavour to defeat dangers from environment. The technique of reaching and catching patient ought to be connected through free camps, minimal effort medications contrasted with encompassing zones and catching exchange out specialists. On the off chance that the ability of the prime specialist is awesome, settle on troublesome cases left by different specialists with the dread of disappointment. In addition more up-to-date methods and medical procedures ought to be aced by the specialist in such cases.

*W-O*—How can partnerships with other centres help the organization to improve itself and put more effort into patient acquisition? By presenting itself as an accredited apprenticeship provider, the organization will put itself on the market again and its shows that adapt to changing times and wants to offer different kinds of treatments.

• This circumstance has more vulnerabilities—shortcomings, yet its condition gives more open doors like less number of oral specialists in the town and so forth. The procedure ought to incorporate the utilization of these chances while decreasing or amending shortcomings inside. Executing the arrangement step by step is required in such cases. The emphasis ought to be on improving the patient experience by great work by prime specialist, less staff and nearly not all that extravagant set-up amid introductory stage. Along these lines, cost cutting should be possible successfully without settling on the treatment plan. As the patient information and OPD increments, further advances can be taken for extension.

*W-T*—How can the organization better position itself in the market and thus reduce the threat posed by competitors? By presenting itself as an accredited apprenticeship provider, the organization can claim that they are a serious competitor and can possibly offer healthcare services by apprentices at reduced rates, with the work still being done by the prime specialists.

• WT circumstance—smaller than usual little methodology. This circumstance is without any advancement openings. It works in antagonistic situations, and its potential for change is little. It doesn't have huge qualities, which could withstand dangers. Scaled-down smaller-than-expected technique comes down to a negative rendition of the shut down or in idealistic circumstance—to take a stab at survival keeping in mind the desire of restoration. Advertising is the key in such cases alongside advancement of uncommon careful just as relational abilities of the prime specialist. Additionally, creating specialty brands are of signifcance as the abilities are not present with basic maxillofacial specialists. These brands include clefts, oral oncology, all out TMJ substitution and so on [17].

	- Does the plan give a key suggestion that will lead the setup to a truly remarkable position thinking about the challenge?
	- Does it offer an incentive in an alternate manner?
	- Are the key decisions that have been made substantial in the long haul?

On the off chance that there are negative answers, the detailing ought to be looked into to check whether, rather than shaping a key arrangement, an arrangement has been made with a progressively restricted scope [16].

#### **43.4.3.3 Operational Planning**

The point of operational arranging is to make the arrangement totally explicit, viable and unmistakable. The Operation destinations unite the accompanying attributes:


• Each Objective must have the fnancing and different assets (staff time, gear and so forth.) important to accomplish the goals.

When all the OOs are detailed, the execution has to be incorporated with that of the others inside a course of events of activities that incorporates every one of them and gives an outline of the connections, timing and succession of errands, just as the joined endeavours that the HO needs to perform at each stage.

#### **43.4.3.4 Assessment of Results**

Auspicious evaluation of results ought to be done, which is dependent on development of number of patients, nature of administrations, nature of medical procedure, income age and work fulflment. This should be possible by fguring the development charge. Arbitrary overviews on the web or discontent ought to be fnished with the assistance of patients to keep up the pace of association and know the dimension of fulflment of the patient with the health care providers, i.e. the head and the staffs. Likewise, number of patient waiting ought to dependably increase steadily for a feasible growth [16].

### **43.4.3.5 Marketing Oral and Maxillofacial Surgery** [20]


### **43.4.3.6 Staf Hiring**

The staff should be skilled in their work and maintain a humble and empathetic attitude. Always hire and maintain the correct staff


#### **43.4.3.7 Communication**

Communication or Correspondence is most imperative for achieving the great name as an expert. Thinking from the patients' point of view and attempting to clarify in straightforward however non-phobic words about the method will help in building up the trust of patient for the specialist. This will likewise spare the legitimate ramifcations if there should be an occurrence of adversity, which can emerge by not disclosing the intricacies appropriately to the patients. The way toward relieving a patient requires an allencompassing methodology, which includes contemplations post treating a malady. It warrants a few aptitudes in a specialist along with the specialized ability. Studies have showed great correspondence ability in a specialist improves patient's consistence and general fulflment. There are fundamental standards of rehearsing great correspondence. Persistent tuning in, compassion, and focusing on the para verbal and non-verbal parts of the correspondence are the essential steps that are often disregarded. Appropriate data about the nature, course and forecast of the infection are essential. Additionally, patients and orderlies ought to be clarifed about the need and yield of costly examinations and dangers/benefts engaged with obtrusive strategies. One ought to be mindful while overseeing troublesome experiences and breaking awful news. Formal preparation of the specialists in improving relational abilities is vital and has demonstrated to improve outcomes. Furthermore, it is additionally helpful in overseeing diffcult clinical experiences. This way diminishes the disappointment of both the specialist and the patient or chaperon in circumstances of enthusiastic upheavals. It has also appeared to diminish work pressure and increase work fulfllment [22].

#### **43.4.3.8 Record Keeping**

Record keeping is vital to a successful practice especially in view of the legal implications that come along with a failure to maintain the same. One should maintain both a hard copy and a virtual copy of their records as backups are most essential. Informed consent forms should clearly record possible complications in a language understood by the patient. Photographic records at the preop, intraop, and postop phases need to be maintained and become especially important when a patient has unrealistic expectations. It is also important to maintain well-documented out-patient records and operative notes. Never forget the seventh principle of the Caldicott report, an NHS report on patient information, which says '*the duty to share*  *information can be as important as the duty to protect patient confdentiality*' [23].

#### **43.4.3.9 Reformulating the Strategy**

If at any point of time you come to realize that your practice is unable to achieve patient needs or fnancial goals, it is time to reconsider your strategy [16].

#### **43.4.3.10 Professional and Financial Growth in Career**

Nothing is permanent in life and in one's career. You can run your profession for a particular timeframe to be trailed by slow decrease in the training with age. Wellbeing and prosperity play a vital depiction to build the life span of the training (Fig. 43.4a). Till 45 years, there is a tendency to achieve followed by continuous decrease in the feld. The thought is to augment the achievement with slow decrease. A specialist can viably work till the age 55–60, which can be expanded till 65–70 with great wellbeing and consistent learning. It is the duty of old specialists to offer approach to novel specialists for the improvement of feld. Supportable model can be made to prepare novice specialists followed by naming them as partners.

#### **43.4.3.11 Time Management** (Fig. 43.4b)

Time is the most essential commodity that we have in our lives. Digitalization of many facets of hospital management has helped save time. This time can be re-invested in various other aspects of your clinical practice like discussion regarding treatment planning and discussion of various cases. Make sure you plan your day daily and weekly so that you are aware of the time that you have and be able to invest it wisely [24].

#### **43.4.3.12 Management of Finances** (Fig. 43.4c)

One must learn how to handle fnances appropriately; unnecessary and exorbitant spending at the earlier stages is not a wise idea and can lead to a sudden fnancial crisis, which can even lead to the premature end of one's career. As mentioned before, expansion and modernization of the practice should follow a well-thought-out long-term incremental approach. Similarly, it is wise to slowly create an alternate source of income to help tide over any fnancial crises that one may face throughout the course of their career [25].

#### **43.5 Conclusion**

Oral and maxillofacial surgery is gaining popularity as a feld and general awareness is increasing in India. It is the responsibility of new surgeons to contribute their best to the feld in order to get the maximum out of their careers

**Fig. 43.4** (**a**) Professional life cycle of oral and maxillofacial surgeon. (**b**) Time management in the life of a maxillofacial surgeon. (**c**) Finances management in the life of a maxillofacial surgeon

and life. As is said 'Do good and it will come back in unexpected ways to you'. Never lose your principles and ethics in this competitive world as it will only tarnish your reputation. Everyone has a specifc purpose in this world. The aim is to fnd that purpose and work upon it with the help of the skills and knowledge you have gathered. These were my rules for success that I stumbled up on while achieving my goals. The newer generation is getting smarter and sharper and will surely contribute to a new set of rules and redefne success.

'Those are my principles, and if you don't like them, well, I have others'—Groucho Marx

**Disclosure** Authors have no fnancial conficts to disclose.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

**44**

## **Medicolegal Issues in Maxillofacial Surgery**

George Paul and Manjunath Rai

#### **44.1 Introduction**

In the modern world, human activity is governed by a set of rules and regulations collectively referred to as law. All professions must follow legal requirements and this is especially important while practising health care, including maxillofacial surgery. Doctors must be aware of their duties, rights and scope of practice within the framework of the laws governing their respective countries or states. This is especially important for maxillofacial surgeons, who straddle the line between medicine and dentistry. This chapter aims to outline the various legal issues that pertain to the maxillofacial surgeon. The laws referenced are mostly India centric, but the general principles are not very different from international laws.

#### **44.2 What Are the Legal Issues That Must Concern the Maxillofacial Surgeon?**

Since the role of a maxillofacial surgeon acts as a link between the medical and dental professions, the scope of practice has always been controversial. Maxillofacial surgeons have moved from beyond the oral cavity to the head and neck region, and even to distant body parts for procedures such as fap harvesting. All maxillofacial surgeons must be aware of what procedures they are allowed to practice under the law and what they must avoid.

During any procedure, legal documentation is of utmost importance. These include informed consent and fling medico-legal reports. Informed consent is a legal necessity to prove that a patient is willing to undergo a procedure.

M. Rai

Medico-legal reports must be fled when one treats a case that could potentially become a legal issue. Maxillofacial surgeons may be called upon to testify as expert witnesses in legal cases such as assault and road traffc accidents. They should therefore be aware of procedures required to document evidence in these cases.

Finally, all medical professionals are vulnerable to malpractice suits. The surgeon must be aware of what actions could put them at risks for facing such suits and what procedure must be followed if one ever faces a malpractice litigation.

#### **44.3 Scope of Practice of Maxillofacial Surgery as per the Indian Law**

#### **44.3.1 Historical Perspective**

Oral and Maxillofacial Surgery has a unique place in the health care systems around the world. It is a stand-alone speciality in modern medicine that has its provenance in dentistry. However, when one realizes that modern medical systems are barely more than a century old, it is not long ago that the treatments of dental and oral diseases were a part of an integral system that encompassed holistic health care.

Dentistry as a separate autonomous specialty is an accident and an aberration in the history of modern medicine. In fact, the frst dentists were medical doctors or surgeons like Pierre Fauchard in France who had a special interest in treating dental and oral conditions [1] and John Hunter [2] in England.

In the late nineteenth and early part of the twentieth centuries, dental schools and curriculums were established as courses separate from medical courses and the bifurcation became an established practice in different countries in almost all continents [3, 4].

It is through this prism that we need to view the speciality of OMFS and its future as a complex and distinct part of health care. In fact, training to become a maxillofacial

G. Paul (\*)

Kerala University of Health Sciences, Thrissur, Kerala, India

Dr MGR Medical University, Chennai, Tamil Nadu, India

Department of OMFS, A. J. Institute of Dental Sciences, Mangalore, Karnataka, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 883

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_44

surgeon through the route of dental surgery is unique when compared to other distinct regional specialties, which emerge as a post-medical qualifcation, e.g. ophthalmology, otolaryngology, or gastroenterology.

Realizing the need for adequate training in surgery, substantial additions were made to the dental and oral and maxillofacial surgery curricula by including several basic medical sciences and clinical medical subjects in the undergraduate and post-graduate level, to help meet the medical training requirements of a surgeon.

The impetus for the evolution of OMFS was provided by the two World Wars of the twentieth century and other armed conficts, where dental and oral surgeons were found to be invaluable in the treatment of facial bone fractures. Thus, Oral and Maxillofacial Surgery was born as a speciality of dentistry and went on to encompass a wide range of surgical work, including pathologies of the mouth and jaws, TMJ surgeries, surgical corrections of dento-facial deformities and cosmetic surgery of the face.

In many countries, including those in Europe, this resulted in the concept of dual degrees (medical as well as dental degrees) to better address surgery in a complicated region of the body where one needed a clear understanding of surgical principles as well as sound dental concepts. Duality is often mistaken for an additional medical degree. In fact, duality includes the need for a dental degree for those with a medical background. In countries like USA, India and several Asian countries, oral and maxillofacial surgery continues to be a surgical speciality of dentistry, although some surgeons chose to do medicine as additional qualifcation to further their interests and knowledge [5]. Similarly, dentistry was offered as an additional degree for those with medical qualifcations only. Dentistry was however an essential pre-qualifcation to become a maxillofacial surgeon. It must be remembered that 90% of the world population is still serviced by OMFS with a single dental qualifcation re-enforced by rigorous surgical training as part of their post-graduate curriculum. This includes the USA, Canada, Latin America and the Caribbean, Africa, China, Russia, Central Asia, South Asia, Middle East Asia, South West Asia, Japan, and Far East Asia [6–12]. Starting in the 1970s, several countries also offered integrated 6–7 year residencies leading to OMFS that provide an additional Medical or Dental degree depending on their original background.

The curriculum for Oral and Maxillofacial Surgery in India and several other countries has been suitably modifed for patient safety and competence. In India, the speciality of OMFS is regulated by the Dentist Act of 1948 as more than 90% of OMFS are dental-qualifed surgical specialists [13]. OMFS has been included as a recognized speciality with distinct privileges in the medical health care system and has been included in signifcant legislations at the national and state levels, including the Clinical Establishment Act of 2012.

#### **44.3.2 Current Legal Privileges**

Oral and Maxillofacial Surgery is a recognized department in most multi-specialty hospitals and they are given privileges such as admissions and autonomous departments within the surgical or dental services.

The Dentist Act has defned Oral and Maxillofacial Surgery as a surgical branch of dentistry dealing with diseases affecting the mouth, jaws, and face. The updated curriculum of OMFS is a focused training in surgical management of diseases, injuries and deformities of the face and gnathic system. Training includes interdisciplinary rotation with allied surgical specialities and standard competence in dealing with complex surgical situations in the mouth, jaws and face.

In an increasingly competitive surgical arena, different surgical specialities compete for ownership of procedures based on their diverse backgrounds. It is therefore expected that OMFS, as an emerging surgical specialty, is sometimes in confict with other specialities.

The legal competence to perform procedures is dictated by the qualifcation and training received as part of the curriculum set up by the respective statutory bodies through due process of law.

The legal remit and privileges of OMFS in India are based on the training received as part of the curriculum of the master's degree in Oral and Maxillofacial Surgery as outlined by the Dental Council of India in its regulation issued from time to time. The current syllabus, curriculum and training equip the specialist to deal with a wide range of surgical procedures in the face, jaws, oral cavity and teeth. This includes comprehensive management of defects or deformities of dento-facial region caused by congenital anomalies, injuries or surgical ablation. However increased competence, like in any other surgical speciality, is achieved through experience and continuous training in the form of fellowships and structured courses.

Oral and Maxillofacial Surgery falls into a grey area, overlapped by several other surgical specialities. However, competence is defned by the scope offered by legally approved training within the framework set out by the statutory bodies in the respective countries. In India, OMFS is an advanced surgical specialty of dentistry and its remit is regulated by the Dental Council of India.

#### **44.4 Legal Requirements to Be Followed When Dealing With a Patient**

#### **44.4.1 Informed Consent**

Consent to medical treatment as an ethical and moral principle is probably as old as medical science. It is inconceivable that a medical practitioner at any point in history would have treated or operated on a patient without his or her permission. However, consent to treat as a legally binding entity is of recent origin. Today, it is validated by multiple principles drawn from social and behavioural sciences, moral philosophy, human rights, ethics and laws of a particular country. One of the main guiding principles of Informed consent involves the rights of patients to make clear assertions of what can or cannot be done to their bodies based on unbiased and full disclosure of the benefts and risks that will ensue from treatment. While most diagnostic treatment procedures are today performed only with a clear informed consent, there are some which attract particular attention in the matter of informed consent, e.g., HIV testing and high-dose radiation in vulnerable patients.

#### **44.4.1.1 Defnition and Principles of Informed Consent**

Farlex's free online dictionary [14] has a simple defnition of Informed Consent. It is "Consent by a patient to a surgical or medical procedure or participation in a clinical study after achieving an understanding of the relevant medical facts and the risks involved." A more descriptive defnition is sometimes employed to capture the nuances of informed consent. It may thus be defned as "Consent given by a patient after understanding his/her condition, procedure, risks and alternatives based on unbiased information by the medical professional in a language and manner which is unambiguous, lucid."

#### **44.4.1.2 History and Theory of Informed Consent** [15]

The key historical signposts in the evolution of the Informed Consent as a valid legal document can be traced to cases from the US judicial system, though the basic principles fnd their roots in English Common law.


Canterbury Vs Spence Case (1972) [16]. Thereafter, not obtaining informed consent became legal violation, equivalent to assault or "battery".


#### **44.4.1.3 Types of Informed Consent** [17]

Informed consent may be of two types:

	- Implied Consent: It is given by the behaviour of the patient, such as entering the clinic and opening the mouth to be examined, etc.
	- Oral Consent: It is acceptable for inconsequential procedures such as examination, taking of impressions, or even routine low-exposure X Rays, etc.
	- Written Consent: While oral consent is an acceptable consent, it can often be challenged and the consent cannot often be proved or validated. It is therefore more binding to give a written informed consent.

#### **44.4.1.4 Informed Consent in Oral and Maxillofacial Surgery**

Informed Consent for orthognathic surgery is particularly important because of the nature of the procedure. It is an elective procedure and the patient often seeks treatment for enhancement of aesthetics and function. The expectations are high and therefore the scope for disillusionment as well.

Orthognathic surgery is a highly skilled procedure in a complex anatomical area. Treatment often involves multiple specialists, including orthodontists, anaesthetists, general dentists, and other surgical specialists like neurosurgeons, otolaryngologists, or plastic surgeons. In addition to results falling below expectations, which are largely subjective, patients may also have morbidity in the form of neurological defcit, infections, occlusal discrepancy, TMJ problems, and in rare situations excessive exsanguinations and even death.

Maxillofacial Surgery is a unique speciality of dentistry and medicine and involves complex procedures and outcomes. Some of the procedures are cosmetic whereas others are ablative. Being a surgical procedure involving the mouth, jaws and face, there are several issues of deformity and disability.

The informed consent should include the following (Box 44.1):

#### **Box 44.1. Components of Informed consent for surgery**


Irrespective of whether the surgery is a minor dento-alveolar extraction or major reconstructive procedure, it may be cautious to take an informed Consent, which includes chance of injury or consequences that have disutility for the patient. While operating as a team there are decisions that can be taken jointly by the other members in the treatment process, e.g., Neurosurgeons or orthodontists. For instance, in orthognathic surgery, the Informed Consent Document may have several distinct parts. Gasparini G, Boniello R et al. suggest a threepart informed consent to include pre-op orthodontics, orthognathic surgery and post-op orthodontic treatment [17].

The informed Consent document may need to include the following principles and the surgeon and his team can make appropriate changes to accommodate them. These have been enunciated by Lord Scarman in the case of Sidaway v Board of Governors of Bethlehem Royal Hospital [18].


In addition to this, in the Indian context:


Recent concerns have suggested that informed consent should also cover diagnostic tests. It is a common practice in some countries, including India, to do a routine HIV testing. These can be undertaken only with an informed consent, including pretesting counselling. Many countries also insist on informed consent for multiple high-dose radiation, especially with the use of CT scan.

\*\*A standard Informed Consent form is attached and can be used as a template. Any change depending on local conditions can be added (addendum).

#### **44.4.1.5 Informed Consent and Negligence in Oral and Maxillofacial Surgery**

Informed consent regulations today are largely governed by the principles of medical negligence rather than the tort of battery as in the early days. Any injury, even expected, may be considered a negligent act if there is no informed consent, e.g., paresthesia following Impactions or BSSO. The situation can be defended if the patient was informed and consent obtained. The civil liability for the same will be similar to the liability for medical negligence.

Similarly, Informed consent does not absolve the surgeon from liability for negligence, if it is proved that it could have been avoided if the surgeon had exercised reasonable care.

In short, liability for negligence can be mitigated by an informed consent, but informed consent cannot totally absolve a surgeon for an obvious negligent act.

#### **Defence for non-information**

Sometimes, the surgeon may encounter a non-reported or rarely reported complication despite reasonable care. In these situations, they can take defence in the principle of "Act of God!!" These are complications or sequels that may not have been anticipated by a reasonable surgeon.

#### **Exceptions for the use of Informed consent**


#### **44.4.1.6 Informed Consent for Clinical Trials and New Techniques**

Informed consent has to be obtained if the patient undergoing the surgery is the subject of a new device, implant, or technique which is not a standard one. In India, devices are not covered by the DCGI (Drug Controller General of India). New techniques on an experimental basis, particularly in teaching institutions, must be communicated to the patient and should be cleared by an Institutional Review Board (IRB) or Independent Ethics Committee (IEC). The ICD requirements for research are clearly enunciated in India by the ICMR.

In conclusion, Informed Consent Documentation is an important and critical part of all treatment plans and often includes invasive or potentially harmful investigations. A proper informed consent that is realistic and involves full disclosure, if the patient is exposed to a chance of injury for which he has no utility, is a necessary part of all treatment protocols. Informed consent documents respect the right of patients to take a decision on how their body is treated based on all available information. It is a moral, ethical and legal obligation to obtain a consent based on credible information. It also provides a safety net for the surgeon when unexpected adverse complications occur.

#### **44.4.2 Dentist/Maxillofacial Surgeons as Expert Witnesses**

Dentists and maxillofacial Surgeons are often called upon to give evidence in case of civil or criminal cases. When surgeons are called upon to give evidence as part of forensic evidence, they need to have a grasp of the subject. Forensic medicine and odontology have been used in many sensational cases in India, the Rajiv Gandhi assassination being one of the better-known ones.

Surgeons are often called upon in other more common situations as well.


Expert witnesses are issued summons as discussed earlier in the chapter. The surgeon is obliged to present himself before the court at the appointed time. He may be questioned by the lawyers of the prosecution, defence or the insurance company, as to the nature of injury and the quantum of disability. The surgeon is to clearly state his/her opinion without ambiguity and should remain non-committal about subjects that they are not sure about. If the surgeon has issued a wound certifcate, the copy of the same will be given to him for reference at the time of testifying. The witness is to merely state the facts. They are not expected to involve themselves with the law on the subject, e.g., Loss of teeth, fracture of jaw, etc. They may answer truthfully to any other question pertaining to the same.

Today, there are only a few quantifed disability criteria for dental and maxillofacial impairment in India. They include "The Manual for Permanent Disability" brought out by the CGHS, WHO, and AIIMS in 1981. A compendium of suggested dental and maxillofacial deformities/disabilities has been suggested by Paul G and Thomas S in the published book *Medical Law for the Dental Surgeon* [19]. It has been extensively used in courts of law. If unsure, the surgeon may state if the injury is grievous or not. He may also elaborate on the actual disability that the defect might cause.

Examples of grievous injuries are:


#### **Duties of Witness**

Failure to appear in court without valid reasons after warrant has been issued can invite contempt of court.

Exaggeration or false statements given under oath are not only unethical, but can invite punishment under sec.181, sec.193.

#### **44.5 Medical Negligence in Maxillofacial Surgery**

#### **44.5.1 What Is Negligence?**

Negligence is usually a civil wrong or tort. It is the single most important issue in medical law pertaining to litigation for damages.

By defnition, negligent torts (civil wrongs) are not deliberate but rather a failure to act as a reasonable person should in the conduct of duties to someone whom he or she owes a duty to.

The liability for negligence can however also be criminal or statutory.

#### **Negligence as Tort (Civil liability)**

It has several formal defnitions, but a convenient one by Alderson explains it rather lucidly as "the omission to do something which a reasonable man, guided upon those considerations which ordinarily regulate the conduct of human affairs, would do, or doing something which a prudent and reasonable man would not do."

For an act to be considered negligent, the following aspects must be present, in regard to a surgeon (Box 44.2).

#### **Box 44.2. Features of a Negligent act**


#### **Exceptions to negligence**

Normally, carelessness is neither culpable nor a ground for legal liability, as there is no wrongful intention. However, in medical negligence, the outcomes have serious implications on the patient in particular and the public in general. The consequences of negligence by a surgeon who owes a duty of care are enormous and the law has imposed a duty of carefulness on the doctor or health worker in the interest of safe practices. However, there are several situations, which do not conform to the strict defnition of negligence. In India, several judicial orders have placed many actions by doctors outside the ambit of negligence.

A review of Consumer cases (Under the Consumer Protection Act) shows that some of the situations mentioned here do not come under medical negligence.


#### **44.5.2 Duty of Care**

#### **Minimum standard of care**

The degree of carelessness for a particular profession depends on the risk that it poses to the person who is exposed to it.

Professional standard of care is therefore that standard of care or skill that is laid down by a body of professionals on behalf of the medical profession and which a surgeon or physician is expected to bring to his duty.

If skill and knowledge fall below this established standard, it will be considered to be negligent. A body of professionals can establish this standard by publication in books, reports of scientifc studies, or by protocols established by them, e.g., text books, journals and protocols created by professional associations. Today, evidence-based science is the hallmark of best practices and is defned by the quality of evidence established through Randomized Clinical Trials (RCT) and meta-analysis of peer-reviewed publications.

When there is a difference of opinion on technical matters, an alternate method recognized by another body of professionals will be acceptable as a valid procedure and will not be considered as negligence. This is ascertained by the application of Bolam's law [20], which recognizes reasonable difference of opinion based on credible evidence or experience among peer professional groups.

The Bolitho test uses a different legal parameter and has undermined the usual dependence on the Bolam test. The Bolitho test goes beyond dependence on just two opinions and looks at credible scientifc evidence as more important than mere difference of opinions.

In this context, it is important to discuss the semantics of customary and acceptable.

A professional cannot adopt a procedure merely because it is customary. Customary standards have been looked at critically because it does not provide incentive to adopt better practices. Because a particular procedure has been done for many years does not make it an acceptable practice. An acceptable practice, on the other hand, is not only time tested but also scientifcally sound. An acceptable practice is usually the product of evidencebased science as opposed to customary practice, which is either anecdotal or proven to be inadequate or irrelevant by scientifc scrutiny.

An often-quoted legal principle is that "The skill, diligence, knowledge, means and methods are not those that are ordinarily or generally or customarily exercised or employed, but those that are reasonably exercised or applied, negligence cannot be excused on the ground that others practice the same kind of negligence."

It may therefore be said that a "health worker is under a duty to use that degree of skill which is expected of a reasonable competent practitioner in the same class to which he belongs, acting in the same or similar circumstances." The Supreme Court has defned this duty in the case of Indian Medical Association Vs V.P. Shanta [21] as "In general a professional man owes to his client a duty in tort (civil wrong) as well as in contract to exercise reasonable care in giving advice or performing services."

Importantly, the court held that this standard should be outlined by the medical profession and it is not the duty of the "lay courts" to decide on what constitutes "standard" care. Negligence, in these situations, may be dependent on the locality, availability of facilities, specialization of the doctor, proximity to specialists and advanced technology. However, it is important to remember the dictum "no man is bound in law to be a good surgeon, but all men are bound *not to act* as a surgeon until he is good and capable as such."

The foregoing dictum indicates that a physician or surgeon should not venture to do a procedure unless he is trained and competent in performing it. Merely admitting that he had inadequate experience is no legal remedy. In other words, it is not legally wrong to be ignorant, but it is legally wrong to act in ignorance.

#### **44.5.3 The Test of Negligence**

#### **The Bolam Test**

This is a classical test widely used in the United Kingdom. The Bolam test is an acceptable test used by the National Health Service of the U.K. when a situation of negligence presents itself as observed in the landmark case of *Bolam Vs Friern Hospital managing committee. (1957) 2 AIIER 118.*

The Bolam test establishes that standard procedures be the basis of treatment. Importantly, it provides for alternate management protocols. If there is more than one school of thought, both alternates will be acceptable as a standard.

#### **Bolitho Test**

In a minority judgment comments in Bolitho, it was emphasized that the word "responsible" in the traditional formulation of the Bolam test meant that responsible practice is that which withstands the scrutiny of "logical analysis" from a judicial perspective. Today, courts are increasingly scrutinizing risk analysis from a patient view point, which undermines the traditional view point of only the care giver.

#### **Negligence—Carelessness vs. Recklessness**

While both words have almost the same meaning, there is a small difference. A careless person may not think of the eventuality while being careless. On the other hand, the reckless person is fully cognizant of the injury that his act may cause, but still takes the risk of possible injury. The former is passive, whereas the latter is an active act. Both acts are however are *not intentional* and is therefore often used to describe negligence.

#### **Standards of Care in Hospitals**

Legal standards applicable to hospitals are somewhat similar to those required of doctors or other health workers.

The hospitals are bound to maintain standards in two ways.


In addition, the hospitals may be answerable for the negligence of their doctors, nurses and other health workers through what is called vicarious liability.

#### **44.5.4 Contributory Negligence**

In some situations, negligence arises fully or in part due to the patients or the complainant's fault. As the patient, wholly or partly, contributes to the negligent act, it is called contributory negligence.

The standard to be adopted to assess contributory negligence is somewhat similar to the standard adopted for the doctor. It may be said that 'contributory negligence is when a competent adult (patient) may be negligent by contribution when his conduct falls short of the degree of care that society expects a reasonable person to do or not to do for his own safety'. This would obviously preclude children and mentally incapacitated adult.

Examples


#### **44.5.5 Remedy for Negligence Under the Indian Legal Systems**

Negligence can be


The punishment under the law of Tort (Tortious liability) is unliquidated damages, i.e. whatever damages the judge wishes to award depending on injury, circumstances and other consid-

erations like age, earning potential, profession, etc. If an implied agreement was made between doctor and patient, then the remedy would be as specifed in the contract. The judge may order a specifc performance to do or not do something he has agreed to. However, guarantees for treatment are against ethical guidelines for treatment and it is not applicable in medical law.

If the complainant seeks punitive action against the doctor, he may fle a criminal case under the relevant statutes. The Indian Penal Code for example, has provisions to punish doctors for death or disability. The remedy under criminal law is always in the form of a punishment (Penal). It may involve imprisonment or fne or both. Rarely, the court can order compensation or specifc performance as well. Criminal law sees negligence as a crime against the state and not just against the plaintiff.

Doctors may also be liable under professional statutory laws governing the practice of the profession. In India, statutory bodies such as the Medical Council of India or the Dental Council of India can prescribe punitive action in accordance with laid down laws. The laws can be initiated only against persons registered under the particular statutory body. The Medical Council of India, for instance, cannot take action against a dental-qualifed maxillofacial surgeon.

In some instances, a doctor may not have to answer for his negligence directly. The hospital or establishment employing him may have to answer to the allegation to negligence. This is called vicarious liability and is usually relevant to salaried employees who work for a contract of services and not a contract for services.

However, in practice, for the sake of regularity, it may be said that all permanently or part-time employed doctors are only vicariously liable. However, if the patient is admitted by a doctor in his personal capacity, then the doctor will be personally liable.

#### **Contractual nature of liability**

In a doctor patient relationship, an implied contract is established when a doctor accepts a patient for treatment. A breach of any aspect of this implied contract may amount to negligence when the doctor is under duty to


This may be considered the contractual nature of medical liability. However, Medical ethics does not provide for a written contract, which can be violated as in the case of a commercial transaction. So any liability based on breach of an implied contract will essentially lie within the realm of tortious liability.

Written contracts with promise to cure, failing which a refund is assured is against the ethics of medical or dental practice. It is this author's view that such contracts can be technically void, considering the ethical and legal issues involved.

Tortious Liability is usually dealt with in Civil Courts. In India, medical negligence comes within the ambit of the Consumer Protection Laws established to provide speedy relief to plaintiffs seeking redressals for goods and services that fall short of standards. The Consumer Protection Act defnes medical care as contract for services, which makes doctors and hospitals liable under the Consumer Protection Act of 1986. The Consumer Courts are quasi-judicial legal redressal forums established for speedy justice. They are tiered under the District, State and National Forums depending on the place of the cause of action and the pecuniary jurisdiction (amount claimed as damages).

#### **Criminal Liability**

This liability normally lies with an identifable individual or groups of individuals. However, recent trends indicate that Hospitals also may be held vicariously liable just as in civil liabilities.

Criminal liability is penal and involves punishment in the form of imprisonment or fne or both. Criminal negligence is considered to be a crime against society and not just the aggrieved party and is in violation of penal codes of countries. In India, it is a violation of various sections of the Indian Penal Code 1868 (amended several times).

The important offences inviting criminal liability with regard to negligence are:


While these are the common sections under which a doctor may be liable, other sections also apply. Any offence against the human body (Sec 299 to Sec 377) or offences against property (Sec 378–462) can be used against doctors, e.g. abetting suicide, causing miscarriage sec 312–316 (subject to exemption from the Medical Termination of pregnancy Act 1971), etc.

Sections 78, 80, 81, 87, 88 are directly or indirectly relevant to the medical practitioner. Some can be used in defence of the doctor accused of negligence. Section 88 for instance is an act done in good faith not intended to cause death. It is a good defence in emergency care. Sections 86 and 87 IPC are in respect to harm or death caused by an act not intended to cause harm or death and is done with consent in the best interest of patients. Section 499 deals with defamation. It can be used by doctors to counter malicious charges by patients intending to spoil the good name of the doctor by frivolous or vexatious charges. It can also be used by patients as a criminal violation of confdentiality statutes. For example, revealing HIV status when the patient is not likely to be a public health hazard.

It is important to understand some terms in connection with criminal liability (Box 44.3).

#### **Box 44.3. Terms related to criminal liability**


It is important for the surgeon to be aware of these liabilities. It is also important for him to understand his rights. For example, bail is a matter of right in the foregoing situations and it is to be given by the police offcer attempting to arrest a medical professional. Bail is granted on the surety given by the doctor or a colleague. A doctor can give surety on his own reputation. The burden of providing reasons for refusing bail rests on the police offcer and he will have to give convincing reasons for *not granting bail*.

#### **Representations to amend Criminal procedures for arresting Doctors**

Doctors cannot be arrested arbitrarily.

In a landmark case referred to as the Jacob Mathew Case (2002), the Supreme Court of India has prevented arbitrary arrest and detention of doctors even in case of death or serious disability, as a part of treatment. Criminal liability and arrest can only be made on the basis of a credible Medical Board opinion duly constituted or recognized by the Government.

#### **Statutory Liability**

A doctor or nursing home is liable if there is any infringement of Statutes (rules). They then become accountable to a statutory body. The liability depends on the kind of infringement and the provisions in the statute to deal with it. There are many statutes dealing with practice of Doctors and Dentists, as well as Hospitals. Recently, the newly legislated Clinical Establishment Act provides guidelines for the whole of India.

Doctors and dentists may also be liable to other statutory laws such as The Pollution Control Board and the Drugs and Cosmetics Act, etc.

#### **44.5.6 Legal Procedure and Evidentiary Requirements**

(With special reference to medical/dental Negligence)

Legal Procedure (Procedural Law) Relevant to Medical/ Dental Negligence.

It is important for the doctor/dentist to know the legal procedure involved in medical negligence. The legal procedure is slightly different for civil negligence, criminal negligence, and negligence under the Consumer Protection Act.

To understand legal procedures, one must be familiar with some of the procedural laws. They are,


#### **The Evidence Act**

It is a very important procedural law. There are three concepts in Evidentiary Law.


The facts are the material evidence.

The "facts in issue" are those that have to be explicitly proved. The facts in issue are proved by bringing into evidence the relevant facts. Sections 6–55 deal with these relevant facts.

There are also other rules in Evidence Law.

• *Who needs to bring in Evidence?*

The person who has to legally bring in evidence to prove or disprove a fact is said to have the 'burden of proof'". When one has the burden of proof he has:


The general rule (with some exception) is that the onus of proving any particular fact lies with the party who alleges it and not with the party who denies it. In other words, the onus of proof lies with the complainant and not with the defendant.

Negligence can be proved by

	- Another aspect of evidentiary law is *standard of proof*.

The standard of proof in civil cases can be based on probability and circumstantial evidence. However in a criminal case, the standard of proof is more stringent and should be beyond reasonable doubt as sanction in criminal law is more severe and penal in nature.

• The limitation act (1963)

It is the statute dealing with the time limit for various suits, appeals, bail application and other legal actions.

• *Cause of Action*:

This refers to the incident, which has necessitated a legal process. Limitation period begins as soon as the cause of action takes place. The period of time varies according to the suit and it is given in the schedule of limitations.

#### **Appeals/Application for leave of appeals**

For appeals, the day of judgment marks the beginning of limitation period after giving time for obtaining the copy of decree (Judgment Order). This will not include 'writs' as the limitation Act does not apply to them.

If a suit or appeal is made after the statutory limitation period, the court may reject the petition on grounds of being barred by limitation. The court may however accept a petition even if it is barred by limitation, if it is satisfed that the delay was unavoidable. However, in criminal cases, the Act does not provide a period of limitation. Criminal proceedings can be instituted at any time after the offence has been committed. However, as per the guidelines given in Section 468 of CrPC, the limitation periods run thus:


If the limitation period ends on a day when the court is closed, then the next working day is included as the limitation period. It may therefore be said that a suit should be fled as soon as the cause of action occurs.

#### **Court Fees Act (Varies from State to State)**

Any party who wishes to approach a court with litigation has to pay a court fees with some exceptions like the Consumer Court. Each state may have a different court fee structure. In a suit for money, the fee is usually computed based on the amount claimed by the plaintiff. Court fees are paid in the form of Stamps, which may be adhesive or impressed or both.

#### **44.6 Conclusion**

This chapter is unique as most textbooks do not address issues pertaining to law and ethics in practice.

The maxillofacial surgeon is often confronted with questions on their remit and scope of work as it overlaps with several other specialties and is constantly in confict with issues of qualifcation and areas of competence. The sections on these issues will throw light on their practice privileges in addition to dealing with litigation for medical negligence, which has become all pervasive.

**Disclosure** Authors have no fnancial conficts to disclose.

#### **Annexures**

**A.1 AOMSI—Informed Consent Forms for All Procedures https://www.aomsi.com/ WebPages/downloads.aspx**

#### **1. Health questionnaire**















#### **2. Medication questionnaire**


#### **3. Consent for Minor oral surgery**




#### **4. Consent for Implant**


#### **5. Consent for Orthognathic surgery**


	-
	-
	-



#### **6. Consent for TMJ**







#### **7. Consent for Trauma**



#### **8. Requisites for translation of "informed consent" to vernacular languages**

#### **9. Informed refusal of treatment**


#### **A.2 Quantifcation of Disability**

#### **A.2.1 Quantifcation of Dento-facial Disability/ Deformity: A Proposal** [19]

Form and function are the quintessence of human life. Disability and deformity are interruptions to this harmony. Disability/deformity may be congenital or acquired. Governments have a social responsibility to mitigate such affictions by creating an environment for re integrating them into normal social life. Most welfare states provide benefts for persons with disability.

Disability can also be caused by accidents, interpersonal violence and iatrogenic causes. These situations have legal overtones and often require compensation in some form. Benefts and compensation can only be calculated if the disability is quantifed. Orthopedic disabilities in Civil and Military life have been calibrated and quantifed. Similarly other disabilities involving loco motor, neurological, visual and hearing defcit have also been quantifed. Unfortunately the maxillofacial region has not been adequately addressed in any of these quantifcation charts.

Quantifcation of the maxillofacial region is unique on account of the fact that there are two criteria to be evaluated— Disability and Deformity. While disability is more readily calculated, deformity is highly subjective and therefore any award for the latter is bound to be arbitrary. However it is not possible to ignore the importance of deformity to the face, and an attempt is made to establish a broad parameter in which it can be assessed.

#### **Review of Quantifcation Criteria**

Quantifcation of orthopedic disability is well established and has been in use for social benefts, rehabilitation, assistance and percentage reservations in labour market placement of disabled people. It has also been in use for legal and insurance compensations due to accidents, interpersonal violence and occupational diseases. The Phulhems profle by the Canadian Army was established as early as 1943. The McBrides criteria was the established reference in India till 1980. It did cover some aspects of the maxillofacial region and was generally accepted for dental injuries and dental loss. The McBrides criteria (1955) was replaced in India by the "Manual for Doctors to Evaluate Permanent Physical Impairment" (1981). Unfortunately the impairment and disability of the face is covered rather incomprehensively and inadequately, relegating the whole area of the face to one half of a chapter, with hardly 30 points being allocated to the face. Not one maxillofacial surgeon sat on the expert committee of 45 advisors. In the realm of physical rehabilitation and orthopedics, numerous references are available. Kessler (1970) covered various aspects of upper and lower extremity disabilities. The American Academy of Orthopedic Surgeons Manual (1966) discusses the concept of permanent impairment through a series of questions that reveal the permanency of the defcit. The Govt. of India notifcation (1986) covers visual disabilities, locomotor disabilities and hearing and speech disabilities. It recommends that Kessler's formula can be taken as a general guideline.

Signifcantly the only other Indian guideline for Maxillofacial region comes through a Government of Tamilnadu notifcation (1974) where complete facial disfgurement is dealt with. It simply awards a 50% for total facial disfgurement. No break up fgures is given for type or severity of disfgurement.

The American Association of Oral and maxillofacial Surgeons and American Medical Association have given guidelines for assessment of maxillofacial injuries and disabilities. They however need modifcation to suit our population and needs.

The authors have depended on two major sources while making this evaluation.


The authors have modifed the guidelines of the above sources to arrive at the recommendations.

The general aim of the exercise was to evolve quantifcation criteria for disabilities and deformities of the Maxillofacial region taking into account the special features of the problems encountered in India. It also endeavours to simplify the percentages awarded by eliminating complex variables. **The evaluation adopts a position of awarding a 100% to the face to be divided between deformity (50%) and disability (50%). It does not try to evaluate facial impairment as a part of the total body as it would signifcantly reduce the quantum of impairment and thus defeat the purpose of this exercise.** Consider a situation where 100% has to be divided between cardiovascular, alimentary, central nervous and locomotor systems in addition to sexual dysfunction, liver dysfunction, renal, endocrine and metabolic dysfunctions. Further distribution amongst visual, hearing, etc. will certainly minimize any help of giving value to the face.

The evaluation has also eliminated the need to go into variables like age, sex and occupation, which will modify the award percentages. These will rest within the realm of the government agencies, judiciary or insurance agents.

The criteria formulated shall simply make a statement of disability/deformity based on standards established within the purview of the 100% for the face—equally divided amongst the various structures and functions. **The total of these shall remain within hundred utilizing the formula**

$$\mathbf{A} + \frac{\mathbf{B} \left(\mathbf{100} - \mathbf{A}\right)}{100}$$

**where, A = higher value and B = lower value.**

Defnitions

Based on Govt. of India Gazette Part I section 1 No. 4-2/83— HW III Ministry of Welfare, 1986.8


Recommended Quantifcation for the Dento-facial Region Areas of Deformity Evaluation—Hard Tissues:

#### A. **Loss of Teeth:**


Though these are disabilities and deformities that can be replaced, it deserves the above percentile as the strength and function of false teeth are not considered equal to natural teeth. Orthopedic deformities are evaluated even if prosthesis is given.

Posteriors Disability

– Excluding third molars and including premolars.


**Loss of teeth due to progressive dental pathology (e.g. Periodontitis, caries) are not considered.** The dental surgeon will have to make an assessment based on the condition of remaining teeth or preexisting records.

#### B. **Loss of Bone** (Disability/Deformity)


#### C. **Mal-united Facial Bones: (Depending on extent of Disability/Deformity)**

Malunited facial bones 10–20%

– Occlusion to be combined whenever affected.

This is an incomplete quantifcation and will have to be assessed by the surgeon on the basis of the degree of disability/deformity caused by the malunion.

#### D. **Orbital Deformity (excluding visual feld assessment)**

Subjective evaluation based on: Bony orbit : 5–10% Soft tissue e.g.) etropian, scar etc : 5–10% Composite deformities including Telecanthus etc : 15–25%

#### Areas of Deformity Evaluation—Soft Tissue

A. **Soft Tissue**—**Non-reversible** Single linear scar : 5% Multiple or deforming scars Including Keloids : 10–30% Signifcant loss of soft tissue E.g. Loss of nose, ear, lips etc : 20–50%

#### B. **Facial Sensory Impairment (Ramar)** Face has 34% sensory innervations of whole body.

Ophthalmic : 8% Maxillary : 8% Mandibular : 8%

Tongue : 10%

#### C. **Impairment Rate for Mouth Opening (Ramar)**

Impairment rate for interincisor distance of 4 cm : 0% Impairment rate for interincisor distance of 3 cm : 10% Impairment rate for interincisor distance of 2 cm : 20% Impairment rate for interincisor distance of 1 cm : 30% Impairment rate for interincisor distance of 0 cm : 50%

D. **Motor Disability (RAMAR)** Jaw muscles (masticatory) : 5% right side, 5% left side

Tongue muscles : 15% either side.

E. **Facial Nerve Impairment**

Single branch : 05% Five branches: 25% Zygomaticotemporal : 10%

Bilateral problems are not addressed.

#### F. **Disfgurement criteria (AAOMS and AMA guidelines 1997 and 2002)**


This criteria appears logical and it signifcantly simplifes an otherwise complex quantifcation of facial disfgurement. However we would encourage its use with the other mentioned parameters. The multiple percentages can be resolved with the Kessler's formula.

In multiple disabilities and deformities or when there is a combination of the two the Kessler's Formula A B A <sup>+</sup> ( ) <sup>100</sup> - <sup>100</sup> can be used, where A= the higher and B= lower value

Another formula has also been used by Ramar as per the Government of India notifcation: A B A <sup>+</sup> ( ) <sup>90</sup> - <sup>90</sup> again A being the higher value and B being the lower value.

The formula can be used in a few mock situations.

1. X has an injury resulting in the fracture of the mandible and loss of four incisors. He also develops a pareisis of the marginal mandibular nerve following surgery. His total percentile may be calculated thus: A = 15% and B = 5%.

15 5 100 15 100 <sup>+</sup> 19 25 ( ) - <sup>=</sup> . , whereas the sum of both would have been 20%.

2. Y has an injury resulting in the fracture of both condyles causing subsequent total bony ankylosis. He also has a large scar with keloid on his right cheek. His percentage is calculated thus:

50 20 100 50 100 <sup>+</sup> <sup>60</sup> ( ) - <sup>=</sup> whereas the sum of two injuries would have been 70. Please note that the value adjusts itself as the percentiles go up.

#### Discussion

Quantifying all kinds of disabilities/deformities is an enormous task. This paper attempts to deal with only those disabilities resulting from accidents. Congenital disabilities/ deformities such as those found in cleft—craniofacial anomalies will require a more extensive analysis. Similarly disabilities and deformities caused by aggressive tumours and cancers of the head and neck comprise a wide range of problems, which are not necessarily regional. Cancer in particular may have numerous associated problems ranging from donor site morbidity to psychological impact affecting quality of life and mental depression.

Dental injuries and their resultant disability/deformity are closely linked to aesthetics and mastication. For the purpose of awarding percentiles, the anterior teeth were considered for aesthetics and the posterior teeth for masticatory function. The awards are arbitrary and based on the relative dysfunction caused by the absence of teeth in the masticatory apparatus. The American Association of Oral and Maxillofacial Surgery (AAOMS) guidelines award percentages for the complete masticatory apparatus. It awards 24% for a person who is restricted to liquid diet (40–60% if tube feeding is necessary) and 5–19% if person is restricted to semisolids (includes those with ability to wear dentures). We have taken the liberty of awarding points for individual teeth. However if the whole masticatory apparatus is to be evaluated, one may separately evaluate absence of teeth, occlusal disharmony, TMJ movement (craniomandibular articulation), muscle power etc and arrive at a fgure by using the Kessler's formula of A B A <sup>+</sup> ( ) <sup>100</sup> - <sup>100</sup> .

This appears as a reasonable formula, which accounts for individual disabilities within the framework of the masticatory apparatus.

Further the AAOMS guidelines classifes the percentiles into two categories (1) Percentage of normal. (2) Percentage impairment of whole person. The dichotomy does not seem reasonable and is likely to cause further confusion. Finer details such as lateral excursion etc which, have been dealt with in the AAOMS guidelines have been ignored.

Similarly the concept of deformity and disfgurement has been dealt with differently in the AAOMS and the AMA guidelines. The matter of disfgurement is complicated by issues such as personality crisis and the impact of social acceptance. As suggested earlier this criteria can be incorporated into Kessler's formula, thus resolving the issue of multiple disabilities and deformities.

Finally the question of who can give a disability certifcate. The Indian sources are silent in the matter of maxillofacial injuries. However the law in many American states clearly provides for the role of a Board qualifed Oral Surgeon or maxillofacial Surgeon to issue disability certifcation for the maxillofacial region.

Contrary to general perception, it is not necessary that these criteria need to be made by statutory bodies. General usage can give legal legitimacy. It would of course be in the best interest of the Surgeon, patient and the public if these suggestions can be scrutinized, amended and enlarged to accommodate a larger spectrum of disabilities and deformities.

#### **A.2.1.2 Duties of Witness**

Failure to appear in court without valid reasons after warrant has been issued can invite contempt of court.

Exaggeration or false statements given under oath is not only unethical, but can invite punishment under sec. 181, Sec. 193.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Research and Publishing in Oral and Maxillofacial Surgery**

George Dimitroulis

#### **45.1 Introduction**

We have all been too quick to make up our minds and too slow to change them. In Oral and Maxillofacial Surgery, our opinions are slaves to our prior experience. Ignorant confdence is what defned early Surgery as there was a distinct lack of interest in proving and promoting what was effective. The "God complex" among early Surgeons meant that what they thought was true did not need scientifc evidence. It is only in more recent times that Surgical practice has embraced evidence to guard against rumour, bias, misconceptions and misunderstandings. Indeed, just in the last few decades we have witnessed the gradual evolution of Surgery from eminence-based practice, the idea that senior experienced Surgeons held all the knowledge, to evidence-based practice, where fair tests are employed to compare one treatment against the other in order to fnd what works best. History has taught us that clinical research leads to reforms in the practice of Surgery while basic research leads to revolutions in Medicine.

Like in most other scientifc disciplines, Surgical research is used to confrm facts, reaffrm the results of previous work, solve existing problems and ultimately develop new ideas of practical value. If you can understand more, you can make better decisions rather than blind guesses which is the hallmark of successful clinical practice. Judgements, predictions and plans are based on the latest available information and should be constantly updated in the light of new information derived from good research. The late British Economist John Maynard Keynes once said "when the facts change, I change my mind". So too, a good Surgeon must be open to new ideas and techniques which are essential to the progress and evolution of each surgical specialty, as change is only possible when key opinion leaders lead the charge.

G. Dimitroulis (\*)

Maxillofacial Unit, St. Vincent's Hospital – University of Melbourne, Melbourne, Australia

Essentially, the greatest discoveries in Surgery are those that force us to rethink our beliefs about human disorders and our role in managing it. Research builds our core knowledge, and the most useful knowledge is one that changes the behaviour and practice of Surgeons. The simple idea of washing your hands before handling patients met with immense resistance from the established medical community in the nineteenth century until the scientifc evidence supporting microbial infection became too overwhelming to ignore. Knowledge increases your ability to predict the outcomes, and the knowledge of bacterial infections was one of the greatest breakthroughs in modern medicine that signifcantly reduced the mortality and morbidity of even the simplest of surgical procedures. Research has been pivotal to the success of surgery over the last two centuries and will continue to be an integral part of all future progress, especially in the rapidly expanding feld of Oral and Maxillofacial Surgery.

Progress doesn't occur in a vacuum; it almost always builds on existing ideas with a series of incremental improvements. That is why most research is used to develop further knowledge on a topic by reaffrming the results, theories and problems of past work in the feld. Occasionally, when trying to solve an existing problem, research may lead to the discovery of new problems, ideas and theories which makes the science of Surgery a dynamic process of knowledge acquisition that has no endpoint.

#### **45.2 The Science of Research**

The word Science comes from the Latin "scienta" which means knowledge or skill. Science is about new ideas and testing these in the most transparent way. What launched the Scientifc revolution was the realization that we do not have the answers to their most important questions. To fnd the answers, experiments are what people devised when they weren't sure of the truth. Ignorance is the starting point of all

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K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_45

science, and curiosity about the world around us is what drives science. The more that is unknown, the greater the opportunity to discover, and that is how research has become an essential tool of discovery.

The word Research is derived from an old French term referring to seeking or searching. Research is all about the ability to test, reproduce, quantify and falsify an idea before it can be fully accepted as scientifc fact. In research we learn more from the unexpected results than from those we anticipate. Understanding the research process helps generate new research questions. The trick is to ensure the right methods are used to answer the right questions. For example, when we are seeking verifcation, we must ask ourselves "Did I build the system right?", while if we want to validate something, we then ask "Did I build the right system?".

Scientifc research is a systematic way of explaining things by collecting evidence which make practical applications possible. The goal of research is not only to yield new knowledge but also to make us better understand existing issues or topics. There are three main forms of Research; Exploratory research helps to identify a problem, while Constructive research proposes solutions to the problem. The third is Empirical research which tests the feasibility of the solution using either qualitative or quantitative methods. Qualitative research collects data in the form of words, images and video which is largely confned to the social sciences but may also have applications in Surgical techniques. The difference between quantitative (numbers) and qualitative (descriptions) research is well summarized by the famous scientist, Albert Einstein, who once said that "Not everything that matters can be measured, and not everything that can be measured matters". The world cannot be understood without numbers, and equally, it cannot be understood with numbers alone.

In Surgery, quantitative research is most often used to establish the existence of causal relationships between variables by collecting and analysing numerical data. By relying on random sampling, the quantitative research method allows for experimental, correlational and descriptive (i.e. survey) results that are easy to summarize, compare and generalize using statistics to determine the relationship between variables. For example, if the research question is about best mandibular reconstruction following tumour resection, the patients may be randomly assigned to different groups, each representing a different mode of reconstruction. If this is not feasible, the researcher may collect data related to the patient's demographics and situational characteristics to statistically control for their infuence on the degree of morbidity following their particular mandibular reconstruction. Often the intent of the surgical research is to generalize from the study participants to a larger population which will require the researcher to employ probability sampling to select the study participants.

**Table 45.1** The scientifc research method


#### **45.3 The Scientifc Research Method**  (Table 45.1)

Scientifc research follows a structured process. Successful research is only possible when asking the right questions, engaging in the right observations, running the right experiments and networking with the right people to elicit ideas and feedback. The core principle of science and research are precision and transparency—being clear about your methods and honest with your results. Transparency is what gives science credibility. World-changing ideas and technology were built from a protracted process of trial and error. Experiments are designed to show what does work and what doesn't. It is by testing that we gain access to the feedback that drives progress. Formal research has a well-established pathway that follows the basic steps set out below.

#### **45.3.1 Observation**

Many people simply watch the world around them (on autopilot). Few people observe. An astute observer will see the problem only when they're not vested in the way things have been. Their ability to imagine how things should be is what drives change and progress. The hardest part of solving a problem is seeing it, and many surgeons blindly follow procedures that do more harm than good for the patient because they have failed to question the surgical technique they have been taught. In surgery, very few surgeons have ever asked the pivotal question—"Is there a better way?" Curiosity and an open mind is what drives progress, and unfortunately, most surgeons have achieved their chosen profession by not rocking the boat and adhering to conventional practices.

Many of the things we accept as objective truths are themselves assumptions based on uncertainty, even in the world of Surgery. No surgical concept or technique has an absolute and permanent value. Time, experience and better experimental tools give rise to new ideas that supplant the old ideas. In other words, all existing surgical ideas and techniques are sooner or later supplanted by new ideas and techniques which means surgery is a never ending marvel of evolution.

Before embarking on any kind of research, the frst step is to look for any idea or technique that has not been adequately explained or supported by evidence. When looking to a topic or issue as a potential subject for research, the hierarchy of deliberation begins with (1) "Where is the evidence?", (2) "How sound is the evidence?" and (3) "Has the evidence been properly interpreted?". Once you have selected the appropriate subject or topic you would like to explore, the next step is to fnd out what the literature has to say and look for gaps in the existing knowledge.

#### **45.3.2 Literature Review**

All the world's information is now at our fngertips, and to access scientifc publications is a matter of a few keystrokes. Search engines like Google Scholar and PubMed have opened up a whole new digital world of scientifc literature that even the largest University libraries could never hope to subscribe to. Access to the world's scientifc literature has never been simpler than it is today, and subscriptions to University libraries also allow students digital access to a wide range of local and international journals.

Once the research topic has been selected, a thorough review of the literature is required to establish what is already known. It is best to begin with the most recent peer-reviewed articles on the topic which will often summarize the existing body of knowledge. Meta-analysis papers, especially those that follow the PRISMA guidelines, are becoming more common, and these papers can form the foundation of your research topic. Good journal papers will commonly highlight the gaps in our knowledge, the weakness in the current evidence available, and what further research is required that will conveniently point you in the right direction.

#### **45.3.3 Purpose of Research**

Once you have gathered all the pertinent information from the literature review, the next step is to crystalize in your own mind why you are embarking on this research. The faws or holes in previous research are identifed so that the gaps in the literature will provide justifcation for the new research being proposed. Look for clues in the literature where there may be a defciency in the evidence surrounding published statements, particularly those that make generalizations that are not adequately backed by evidence. Indeed, many Cochrane reviews have consistently concluded that the vast majority of clinical papers fail to provide the level of evidence required to make any frm conclusions. The aim or purpose of the research is pivotal to the whole project as it dictates the methodology required to adequately address the aims. It is also the main driver in funding applications and recruiting study participants.

#### **45.3.4 Hypothesis**

Science grows with every new piece of evidence with the hypothesis as the compass that directs the inquiries. Scientifc theories have to make testable predictions that can be validated in experiments. Science is not just about confrmation; it is also about falsifcation. If a theory cannot be tested, then it's logically impossible to ever falsify it. Karl Popper said "if it is not falsifable, it's not scientifc". If a theory cannot be tested with experiments, then it falls in the realm of religion or philosophy or pure speculation. Questions that generate the greatest emotional response are a great indicator of challenging the way things are.

The gap in the literature creates a research question which is otherwise referred to as the Hypothesis. The Hypothesis is a prediction which is set out as a statement that defnes the relationship between two or more variables. In research, it is the hypothesis that is being tested as to whether it is true or false. If the hypothesis turns out to be consistent with the observations, then it is said to be supported rather than proven as it is still subject to further scrutiny. But if it is rejected, then support is claimed for an alternative hypothesis. The Null hypothesis is when there is no relationship between the variables being investigated.

#### **45.3.5 Defne the Variables**

In the hypothesis statement, there will be two or more variables that will be the focus of the study. The study is designed to establish the relationship between the variables. However, before commencing the study, the variables must be clearly defned so that there is no doubt as to what each variable represents. Without clear defnitions of the variables, studies cannot be repeated and hence impossible to validate.

#### **45.3.6 Data Collection**

What isn't measured can't be managed. Without data, we cannot make informed decisions. We gather data to collect information that becomes knowledge which is fnally displayed as wisdom. Data has to be collected, processed and analysed for it to become information which can be used to make better decisions. Ultimately, the answer is only as good as the quality of the data fed into it.

Apart from feld studies such as surveys and clinical audits, OMF Surgeons also conduct experiments that involve laboratory controlled conditions, often by recruiting the resources of other medical specialities such as pathology, microbiology, radiology, biochemistry, pharmacology and haematology. Data collection is easiest when data points can be quantifed or represented with numerical fgures. Even descriptive surveys can be quantifed provided the responses can be listed on a sliding scale ranging from good to bad, high to low or positive to negative. A typical example is the visual analogue scale used by OMF Surgery researchers to quantify pain scales, chewing ability and quality of life outcomes before and after jaw surgery.

In Medicine, randomized trials where the patients and experimenters are blinded are least vulnerable to bias than observational studies, which are most prone to bias. Unfortunately, randomized trials are more expensive than observational studies and require a lot more manpower and resources to properly execute. In surgery, we most commonly rely on observational studies as the best evidence we have to go on for two reasons. Firstly, control groups with which to compare treatment outcomes, unlike a placebo sugar drug, are rare as it is ethically impossible to undertake sham operations. And secondly, it is practically impossible to blind surgeons and patients when it comes to evaluating surgical procedures. Evidence in the feld of Oral and Maxillofacial Surgery therefore relies largely on observational studies derived from surveys and clinical audits of case series.

#### **45.3.7 Data Analysis**

Data science is about understanding the world by spotting patterns and predicting how one variable will affect another. While our instincts may give us a reasonable sense of how the world works, we need data to sharpen the picture as we can be easily blinded by our own experiences and prejudices.

Data shows us there is more to OMF Surgery than we think we see. Good data science can often demonstrate counterintuitive results—what you least expected to see. Selection biases are distortions of the results introduced either by the data collecting tools or by the method of data accumulation.

Statistics is a valuable tool that helps determine whether the results you have found are likely to be due to a chance rather than a true fnding. Make sure the data is collected on an Excel spreadsheet, and work out what level of confdence you will accept as statistically signifcant which, in clinical research, is often the 95% confdence level (i.e. *P* value <0.05). In statistics, the smaller the sample, the lower the likelihood that it would mirror the broader population. Large samples yield more precise results, while small samples are more susceptible to extreme results. As sample sizes get larger, the statistical calculations from that sample get more precise. Small differences (1%) between two populations being measured require bigger sample numbers than large differences (25%) for the true value to emerge. This is called the power calculation which is an important measure to consider before embarking on any study. Statistics is a complex affair and beyond the scope of this chapter, so the services of an expert statistician may well be useful when it comes to crunching the data.

#### **45.3.8 Data Interpretation**

Information is interpreted by different people in different ways. People can look at the same set of facts and disagree. Data can be manipulated to support any argument. You don't always need a ton of data to fnd important insights. What you need is the right data. Numbers can be seductive. We can grow fxated with them, and in doing so, we can lose sight of more important considerations. When looking at data, it is not the raw crunching power you have that matters most, but what you do with it that is most important. Behind every statistic there is a certain set of assumptions and prejudices. Minds crave certainty, and when they don't fnd it, they impose it so we must keep an open mind when the data does not yield the results we expected to see.

#### **45.3.9 Test or Revision of Hypothesis**

Your judgement call about how the results support your hypothesis is essential to your conclusions. If the data does not support your hypothesis, then it is essential to state an alternate hypothesis that fts with what has been observed. The scientifc method is tailor-made for cherry picking because of its hypotheses and caveats and refusal to embrace certainty. Even in Science, certainty still relies on the assumptions, interpretations and theories of researchers based on what they see. Nothing is defnite, for doubt is an essential operating principle of science. This means that doubt still has a place in all scientifc proofs, so that all evidence is provisional and not fnal. In other words, what you have ascertained in your research is not defnite proof but rather tacit support for an idea.

#### **45.3.10 Conclusions and Recommendations**

The conclusion is a summary of the entire experiment or study that simply states the outcomes observed which must be clear, concise and to the point. Any ambiguity should be highlighted and recommendations made as to how future studies should be conducted to minimize the uncertainty. It may simply be a numbers game where more patients are required, or additional groups such as control patients which may provide a clearer outcome. For example, the effectiveness of Botox in Myofascial Pain (TMD) can never be properly evaluated if there are no control groups (i.e. that have normal saline injected) with which to compare.

The conclusion is the most sought after piece of information that others will frst look at when reviewing your research. Although it sounds rather obvious, the conclusion(s) must be supported by the data; otherwise, the research makes no sense. The onus is on the researcher to make sure the conclusions also fulfl the goals and aims of the study. Recommendations based on the conclusions are essential in providing a practical guide to surgical practice. Research is what drives clinical advances in Surgery, and the change in behaviour of Surgeons can only be achieved with evidence.

#### **45.3.11 Reporting/Communicating/ Publishing Findings**

Research is useless if it is not shared with the outside world. All humanity is now connected by digital technology which has rendered distance, time and costs irrelevant to the distribution and exchange of ideas. The digital world has made recording, storage and dissemination of information, research and ideas virtually free with costless reproduction and instantaneous global distribution. Reporting and publishing research fndings is described in detail in Sect. 5.

#### **45.4 Constraints in Surgical Research**

Cultures that fail to encourage questioning also fail to come up with new ideas. Great institutions should teach us how to ask hard questions and where to look for answers. Knowing all the answers does not distinguish someone's intelligence rather, the ability to ask the right questions and linking the unconnected is the mark of a true genius. Generally, it is considered a weakness and a sign of vulnerability for clinicians to appear unsure. Confdence in medicine is valued over uncertainty, but science is all about uncertainty which drives progress. If we knew it all, there would not be a need for research.

Nothing is as powerful as an idea whose time has come. New ideas are what drive behavioural change and innovation. A new behaviour needs social approval before others are likely to pick up the habit as their own. Only the curious, who are open to learning, have a much greater chance of creating a truly novel solution. Unfortunately, originality is not always embraced by the surgical profession who are generally conservative by nature.

It is much easier for Surgeons to accept familiar ideas than totally original ones because if the ideas are too original, then it may be too hard for the Surgeon to accept or understand. The goal is to push the envelope, not to tear the envelope. Radical ideas are best presented in a way that is less shocking and more appealing to mainstream surgical practice by planting the seeds of a simple idea before revealing the larger idea. If you want your ideas to be accepted by your peers, make your ideas more appealing by connecting it with other ideas that are already understood by your colleagues. Other constraints related to research involve ethics, funding and bias which are discussed below.

#### **45.4.1 Ethics**

There has been a push in recent years by institutions and clinical journals to have all animal and human research activities sanctioned by appropriate ethics review boards or panels attached to hospitals or Universities. Without ethics approval or clearance, it may be impossible to conduct even the simplest of clinical studies, including basic surveys. Some Journals now request a copy of the ethics clearance letter before the paper can even be put out to review.

Unlike pharmaceutical research, the level of evidence in clinical surgery is hampered by the fact that control subjects are often missing because you cannot ethically perform sham operations in humans. Therefore, when designing surgical experiments, consider whether animal, laboratory or cadaver studies may be useful instead. Otherwise, you are limited to clinical audits which provide useful information which may not be scientifcally valid. For example, a hospital which boasts 100% survival of its patients achieves this by turning away the sickest patients. Or a hospital which has the worst outcomes may well be a tertiary referral centre that only treats the most complex of cases that other hospitals turn away. So, while clinical audits provide a snapshot of the Hospital Unit's activities, it tells us very little else as far as science, progress and innovation is concerned.

We must be suspicious of therapeutic claims that have not been properly tested. Equally, we must be even more suspicious of research results that cannot be replicated. Many people are driven by a deep human desire for recognition and affrmation of work well done. Sometimes it is possible to build an academic career by sounding clever, rather than being clever. Most academics chase large numbers of trivial publications instead of investing their energies in new frontiers. In other words, why search for something new when you can collect rents on everything that has already been done. Sadly, there are small numbers of academics and researchers who have built their careers on falsifcation and plagiarism. The desire for recognition and the need for promotion when combined with the pressure to publish can tip some academics, clinicians and scientists towards fraudulent activities where data is made up and text is plagiarized in order to churn out the maximum number of "scientifc" papers. In science and surgery, reputation takes many years of hard dedication to build up and an instant to destroy when you're suspected of scientifc fraud.

#### **45.4.2 Funding**

Scientists have an innate desire to innovate, share, collaborate and be recognized for it regardless of the fnancial incentives. Hence, good research requires funding from external sources. Unfortunately, the spirit of open scientifc enquiry can sometimes be hijacked by the combination of self-interest and money, especially when industry offer to bankroll the study. Industry rely on proftable enterprises which grow shareholder value. Scientifc support behind a product is perhaps the ultimate value-adding marketing tool, so industry are always looking out for research that shows positive outcomes related to their products. Furthermore, industry never leave anything to chance so they want control of scientifc research through fnancial rewards to various research institutions. By directly funding research, industry have control over what is published (i.e. the positive results) and what stays buried in a locked cupboard (i.e. the negative results).

Therefore, the most respectable research is that which is funded by government or not-for-proft organizations such as Medical Societies and disease interest groups like the Heart Foundation or the Cancer Council and so on. Funding from non-industry groups are much more competitive as there is always a limited amount of money available for research so applications must be of high quality. Furthermore, the nonindustry funding bodies give free reign to the scientists on how the data is used and published. Industry funding, on the other hand, have simpler applications but more control of the data which remains their property. Most importantly, industry insist on the fnal veto on whether or not the results are published.

#### **45.4.3 Confrmation Bias**

Confrmation bias is one of the shortcomings of science because the human mind is bad at seeing things it did not expect to see and a bit too eager to see what it expected to see. It is basically seeing what you want to see and ignoring everything else. In essence, confrmation bias is when you flter reality through biases by eagerly accepting evidence that confrms what you believe and ignoring evidence that refutes or challenges what you believe. Once we adopt a particular hypothesis or interpretation, we fnd it diffcult to see things any other way. People will accept any explanation as long as it fts with their own understanding of the facts.

#### **45.4.4 Cognitive Dissonance**

Cognitive dissonance is another impediment to scientifc progress that affects many people. It is simply a feeling of discomfort that people experience when presented with information that is inconsistent with their beliefs. When we are confronted with evidence that challenges our deeply held beliefs, we are more likely to reframe the evidence than we are to alter our beliefs. In most cases, instead of acknowledging an error in judgement, people tend to reformulate their views in a way that justifes their old opinions. We simply invent new reasons, new justifcations, or new explanations or ignore it altogether. Some people go to absurd lengths to justify their beliefs or judgement even when confronted with clear contrary evidence. The more committed we are to a certain opinion, the less likely we are to relinquish it, even when confronted with massive or overwhelming contradictory evidence. As an example, the introduction of microvascular venous couplers in microsurgery was developed by those who could see the obvious benefts of speed and patency of the anastomosis, and yet was resisted by those who felt the skill of micro-suturing tiny veins would be lost, regardless of the benefts of reduced thrombosis and improved fap survival.

#### **45.5 Publishing**

Research cannot thrive without publishing. All research projects are conceived with publication as the end game. The excessively competitive feld of research creates a tendency to rush to conclusions and publish results that have not been properly validated. Valid conclusions can only be drawn from reproducible data sets because results that initially look promising aren't always repeatable. It is little wonder that remarkably few published breakthroughs have ever led to any useful treatments.

There are numerous media that researchers can use to propagate their experimental fndings which are discussed below.

#### **45.5.1 Electronic Media**

Digital technology has not only transformed but has revolutionized the way we live. The merger of the personal computer and the Internet allowed networking to blossom on a massive scale, and so surgeons and scientist are not wholly reliant on print media to propagate their ideas. Websites like ResearchGate encourage scientists and clinicians to upload their research, both published and unpublished, onto a digital platform for all to see and to foster collaboration between research groups across the world.

Digital media platforms like YouTube are fast becoming a quick, easy and virtually cost-free way of publishing your novel ideas and surgical techniques on the Internet for all to see. More and more Surgeons are bypassing the heavily fortifed realm of print media for the highly accessible digital media which not only offers a global audience but also facilitates immediate upload of content with virtually no delay. The disadvantage is of course the lack of scrutiny which suggests the content has not been vetted by experts. Hence, the scientifc value of the video post is virtually zero. While you may have a wide audience, it may not necessarily be the people you want to impress.

#### **45.5.2 Magazines**

Glossy magazines that specifcally target general medical/ dental practitioners are supported by lots of industry advertising which is interspersed with clinical articles that have not been peer-reviewed, but rather submitted on the invitation of the magazine editor. The articles, which often have more clinical pictures than text, are written by clinicians and academics as a general interest piece that provides the reader with an update of what is current clinical practice that is aimed at the non-specialist practicing clinician. Authors are generally paid for their contributions. These articles are of little value to the specialist trainee or clinician wanting to fnd out more about their own specialty.

#### **45.5.3 Textbooks**

Textbooks contain information that is current practice and accepted by the profession. Unfortunately, by the time a textbook is commissioned, written, published and fnally released, the information is often about 2 years out of date. Therefore, the strength of textbooks is in the basic principle of surgical practice, and the weakness lies in the distinct lack of new information. Digital technology is gradually changing the need for printed textbooks as students are gravitating to knowledge that is presented in discrete digital packages with hyperlinks that cross-reference important concepts similar to "Wikipedia". While university and hospital libraries still purchase textbooks for student consumption, today's students are fnding the expense of textbooks prohibitive and so seek other means of accessing surgical information and knowledge through the Internet, which is often up to date as long as they know what to look for and are able to critically evaluate the credibility of the information source.

#### **45.5.4 Peer-Reviewed Journals**

There are over 1 million academic papers published every year in over 24,000 academic journals where gaps in our knowledge are discussed and new experiments are conducted that might resolve these gaps. Unfortunately, published scientifc papers tend to be biased towards reporting positive results. Negative results do not make headlines so they are rarely published. Publication in a journal is not a mark of truth but merely that the research has passed a certain standard that warrants entering the formal literature and further discussion.

Scientifc journals sell scholarship back to the same universities whose scientists had produced, written, peer reviewed and edited largely for free. Hence the cost of producing scientifc journals is kept as low as possible in order to facilitate as wide a distribution as possible. Unlike magazines, peer-reviewed journals with few exceptions keep industry advertising to a minimum as they are supposed to be impartial to avoid confict of interest when reporting studies that may confict with the interests of a big advertiser.

Peer-reviewed journals are the platform we use to announce new discoveries, to comment on or criticize the discovery of others and to synthesize and seek to build consensus about what is known. In Oral and Maxillofacial Surgery, case reports and technical notes account for about one-third of journal publications, while less than one in ten are randomized control (Level 2 evidence) or non-randomized control (Level 3 evidence) studies (Table 45.2). Because of the diffculty in performing high-level randomized control trials in surgery, Surgeons are more accepting of lower-level evidence which is based on observation. Indeed, it is unlikely to extract any high-level evidence research from surgical departments who rely on surgical trainees for their research output.

**Table 45.2** Levels of evidence (Oxford Centre for Evidence-Based Medicine)


the evidence levels of the papers being reviewed. If all the papers are Level 3 evidence, the systematic review will also be Level 3 evidence

**Table 45.3** Factors to consider in the design of a clinical study


**Table 45.4** Criteria for a good surgical manuscript


**Table 45.5** Anatomy of a poor surgical manuscript


All journals subscribe to the IMRD layout which means all submissions must have an Introduction, Methods, Results and Discussion sections. The introduction builds the case for why you pursued the line of research and the fnal sentence is always the statement of the aim(s) of your study. The Methods section describes how the study was performed in terms of setting (e.g. Hospital or Laboratory), subjects (i.e. animals or humans), recruitment (e.g. inclusion/exclusion criteria), data collection (e.g. Surveys, measurements), variables being compared (experimental vs. control) and data analysis (statistics used) (Table 45.3). The Results section simply states the summary of the outcomes as depicted in the tables and graphs, while the Discussion critically analyses and compares the results in light of what has already been previously published on the topic. The discussion must include references that both agree and disagree with your fndings so that a balanced argument can be presented which will add weight to the study.

#### **Table 45.6** Guidelines for formatting papers for publication


The fnal paragraph in the discussion is a summary of the research results with mention of any practical clinical applications that may arise from the study.

Authors must keep in mind that originality and a clear message are essential in getting their papers published in the highly competitive world of scientifc journal publishing (Table 45.4). The high impact factor journals generally attract articles with high evidence levels so it is imperative to select a journal that caters to the subject and evidence levels of your particular study to avoid rejection and delays in publication of your paper. Original contributions that add new information to the existing body of knowledge are more likely to be considered for publication. However, wild or fanciful ideas are unlikely to garner support from journal editors who are looking for papers that lend respectability to their journal.

Unlike works of fction, good scientifc communication is based on clear and concise wording with short titles and tightly controlled sentences that describe complex ideas in the simplest language possible. Poor grammar, emotive language and long-winded descriptive wording must be avoided so that the ideas being conveyed are not buried in a convoluted tangle of discourse (Table 45.5). When evaluating the importance and relevance of published articles, surgeons and scientists look for the facts, not fancy prose.

To improve the acceptability of your paper for publication in a peer-reviewed journal, there are general guidelines available online that help you set out your paper in a format that is recognized and accepted throughout the world (Table 45.6). By following the guidelines, you improve the chances of your paper being accepted for publication. For instance, if you want to submit an observational case cohort study, then the "STROBE" statement will guide you in how to properly format your paper. If it is a case report then it is worth checking out the "SCARE" guidelines. Alternatively, if you want to undertake a systematic review of a topic, the "PRISMA" statement is essential.

#### **45.6 Conclusion**

In Surgery there is no greater accomplishment than being the frst to successfully implement a successful treatment that changes the history of medicine. However, the person with the frst idea is usually not the one recognized by history. Credit often goes to the person who convinces the world, not to the one with the original idea, because the credibility of all new ideas requires convincing evidence. If you make a claim about something, you provide the evidence, or at least a reference to the evidence that backs your claim. Research is the essential tool that builds the evidence which provides a better understanding of how and why things worked or failed. Good surgical practice must be based on evidence.

Surgical innovation is a constant work in progress because any new ideas or techniques are quickly supplanted by an even better ideas and techniques. Gaps in the literature are what fuel research, and the journey of discovery is paved with potholes that need to be flled. To paraphrase the great scientist Sir Isaac Newton, if you want to see further than anyone else has seen before, you need to stand on the shoulders of giants. Your voyage of discovery begins once you have secured your footing on the shoulders of the surgeons and scientists who have gone before you, so you can see the path they have built for you to follow.

#### **Further Reading**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

**Part XV**

**Salivary Gland Pathologies**

## **Salivary Gland Pathologies**

Nisheet Anant Agni

#### **46.1 Introduction**

The salivary glands secrete saliva which has lubricating, immunologic, digestive, and cleansing functions. They are affected by systemic and local infammatory conditions, obstructive pathologies, as well as neoplasms. Most of the tumors are parenchymal in origin, whereas few could be interstitial. Majority of tumors affecting major glands are benign, but those affecting minor salivary glands are more often than not, malignant. The disorders that involve these glands can either be acute or chronic infammatory lesions, congenital abnormalities, systemic disorders, or benign and malignant tumors. However the most, common disorders affecting salivary glands are tumors and infections.

#### **46.2 Surgical Anatomy**

#### **46.2.1 Parotid Gland**

The gland lies in the retromandibular fossa bound medially by the styloid process and superiorly by external acoustic meatus and mastoid process, and it touches the medial pterygoid muscle and mandibular ramus (Fig. 46.1). A part of the gland may also cover the TMJ in front of the ear but never extends beyond the zygomatic arch. The parotid capsule is a dense, adherent fbrous condensation of deep cervical fascia which is tough and unyielding. Hence parotid space infections show minimal swelling but are severely painful. Incision and drainage is needed early on, without a frank fuctuant abscess to relieve the pressure within the capsule to

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_46) contains supplementary material, which is available to authorized users.

N. A. Agni (\*)

prevent pressure necrosis of the parenchyma. Due to weakness in the capsule covering the deep surface of the gland, parotid abscess may spread into the lateral pharyngeal space, if not drained promptly [1]. Benign tumors grow slowly and hence take a longer time to manifest as external bulges. Parotid gland has a superfcial lobe (80%) and a deep lobe (20%) connected by an isthmus with the facial nerve passing between the two lobes.

The facial nerve is related to the parotid gland in a number of ways [2].

	- (b) An isthmus uniting the two lobes.
	- (c) Combination of (a) and (b)

The intratemporal and intraparotid facial nerve has varied pattern of branching which is of immense surgical importance and might show bifurcation and trifurcation of the main trunk within the mastoid segment (Fig. 46.2). This intratemporal division of the facial nerve is associated with congenital abnormalities of the pinna or inner ear (Table 46.1).

Parotid duct or the Stensen's duct crosses the masseter about a fnger breadth below the zygomatic arch. It then takes a sharp turn medially at the anterior border of the masseter further traversing through the buccal fat pad and buccinator muscle. It then runs obliquely between the buccinator and oral mucosa to open on the parotid papilla, opposite the second maxillary molar. The obliquity of the duct in between the buccinator and mucosa acts like a valve to prevent infation of the duct while blowing air. The duct lies between the upper and lower buccal branches of the facial nerve. Its caliber is about 3 mm, but at the point where it penetrates the buccinator muscle, an isthmus narrows down the duct to 1.2 mm, and at the orifce (ostium), it is 0.5 mm.

**46**

Department of Oral and Maxillofacial Surgery, SMBT Institute of Dental Sciences and Research, Nashik, India

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_46

©Association of Oral and Maxillofacial Surgeons of India

Structures traversing the parotid gland from lateral to medial (superfcial to deep) include the facial nerve, retromandibular vein, and external carotid artery. Few parotid lymph nodes are also present within the gland.

Parasympathetic secretomotor fbers from the inferior salivary nucleus of the ninth cranial nerve supply the gland. Nerve fbers pass to the otic ganglion via the tympanic branch of the glossopharyngeal nerve and the lesser petrosal nerve. Postganglionic parasympathetic fbers reach the parotid gland via the auriculotemporal nerve, which lies in contact with the deep surface of the gland. Postganglionic sympathetic fbers reach the gland as a plexus of nerves around the external carotid artery [4].

#### **46.2.1.1 Identifcation of the Facial Nerve** [5, 6]

The facial nerve identifcation can be done either proximally or distally. Proximally the main trunk of the nerve is identifed before it enters the gland. Distally it is identifed as branches after the nerve leaves the gland (Table 46.2).

There are four facial nerve pointers at the stylomastoid foramen. However more techniques have been added later on by various authors. They are as follows:

1. The cartilaginous pointer of Conley (1978) is created at its anterior inferior border and is the least reliable one. The backward pull on the cartilage causes the meatus to assume the shape of a horn, the curved extremity of which allegedly points to the position of the facial nerve. The nerve is located medial and inferior to the pointer (Fig. 46.3).


©Association of Oral and Maxillofacial Surgeons of India

#### **Table 46.1** Katz-Catalano classifcation


**Table 46.2** Facial nerve identifcation


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.3** Showing relation of cartilaginous pointer and facial nerve main trunk

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.4** Showing relation of the posterior belly of the digastric muscle and main trunk of the facial nerve (muscle pointed by mosquito forceps)

the second drawn line along the posterior border of the ramus (angle c). The facial nerve trunk is often found within this triangle just above the angle b formed by the frst and the third line if gentle and blunt dissection is carried out at this point. The mean distance of nerve trunk from the angle b is 12.18 ± 2 mm within a range of 9–15 mm [7] [Fig. 46.5—https://www.ncbi.nlm.nih. gov/pmc/articles/PMC6126203/. doi: https://doi. org/10.1016/j.jobcr.2018.08.004. *(open access)*].

**Fig. 46.5** Borle's triangle. *Line 1: Started from mastoid process tip and running along the superior border of posterior belly of the digastric muscle. Line 2: At the posterior border of ramus of the mandible. Line 3: Starts from the tip of the mastoid process running anteriorly till it joins the second line. Angle a: Lines 1 and 2 intersect with each other forming the apex of triangle. Angle b: Is the base of the triangle. Angle c: Is the angle where third line meets second line*

When identifcation of facial nerve trunk is diffcult using the above said pointers due to distorted anatomy due to the tumor, a retrograde approach can be used by identifying a peripheral branch of the nerve and tracing it proximally. The easiest branch to locate is the marginal mandibular nerve. Baker et al. have reported that the marginal mandibular nerve is located 1–2 cm below the inferior border of the mandible. The marginal mandibular branch can be used to trace the facial nerve in a retrograde direction by identifying it at the point of emergence of the retromandibular vein and then carrying out a proximal dissection. By working backward along the nerve, the two divisions, the other branches, and the main trunk can be found [8].

Figure 46.6 represents the average distance of facial nerve pointers from the surrounding landmarks (Table 46.3).

Intraoperative facial nerve monitoring using electromyographic techniques can also be used for identifcation of the main branch or the peripheral branches in centripetal or retrograde approach. In pediatric population the facial nerve trunk **Fig. 46.6** Distance from facial nerve pointers

©Association of Oral and Maxillofacial Surgeons of India

**Table 46.3** Distance of the facial nerve pointers from the surrounding landmarks [10]


exits the stylomastoid foramen and is found approximately 1 cm anterior to mastoid process and 1.5 cm posterior to the ramus of the mandible. The parotid does not extend posterior to the ramus of the mandible in the newborn infant and consequently covers only the lower distal branches of the nerve [9].

#### **46.2.1.2 Facial Nerve Monitoring**

There are two types of facial nerve monitoring:


Facial nerve monitoring is performed with a nerve stimulator which can either be monopolar or bipolar. The monopolar stimulator is more useful for identifying the nerve, while the bipolar is more useful if the nerve course is evident. However, a bipolar stimulator is more precise.

#### **46.2.2 Submandibular Glands**

It is a U-shaped gland with a smaller deep lobe and larger superfcial lobe enveloping the mylohyoid muscle. Hence during surgical removal, the mylohyoid has to be retracted anteriorly to expose the deep lobe and the Wharton's duct. The capsule is loosely attached to the gland substance, and hence the gland can be shelled out easily.

Since the submandibular group of lymph nodes are in contact with the gland or embedded in it, it is essential to clear the nodes along with the gland during a neck dissection.

The facial artery loops around the submandibular gland. The facial artery is visualized by retracting the posterior belly of the digastric muscle inferiorly. Hence, during excision of the submandibular gland, the facial artery and vein were customarily ligated. However, during neck dissection, the current standard is to try and save it so that it can be used for anastomosis during a free fap reconstruction.

The facial artery is ligated away from the external carotid artery, so that in case the vessel retracts into the tissue, it can be located and religated and bleeding can be controlled. In case the ligature slips and the facial artery retracts, the posterior belly of the digastric muscle is divided for easy location of the bleeding vessel.

The lingual nerve passes below the duct and forms a loop around its outer aspect before inserting into the tongue mucosa. It is at risk when the deep part of the gland is being mobilized. The submandibular duct or Warton's duct is longer and has a tortous, uphill course. Thus the secretions have to be emptied against gravity, and there are increased chances of retention. Also, the mineral content of the secretion is high, especially calcium content which along with increased retention of secretions results into higher incidence of calculus formation and infammatory pathologies in the submandibular gland and duct.

Figure 46.7a, b shows the relations of the submandibular gland.

**Fig. 46.7** (**a**, **b**) Relations of submandibular gland

#### **46.2.3 Sublingual Glands**

They are located beneath the mucosa of the foor of the mouth and appear as an elevation in the foor of the mouth. The excretory ducts of the sublingual glands are very superfcially located and open in the foor of mouth at a superior level than the gland. Hence, they easily get damaged, and any trauma or infection of the ducts leads to salivary retention and formation of a mucous retention cyst which is called "ranula" due to its bluish color resembling the belly of a frog. The international statistical classifcation of diseases and related health problems shown in Table 46.4.


**Table 46.4** International statistical classifcation of diseases and related health problems

10th Revision (Version for 2003) [11]

#### **46.3 Diagnosis and Diagnostic Aids**

A thorough history followed by meticulous examination holds the key to proper diagnosis of salivary gland pathologies. Salivary gland neoplasms are usually slow growing and non-tender. A slow-growing swelling of the salivary gland is suggestive of a neoplasm, whereas a sudden, painful swelling is suggestive of an infective pathology although it can sometimes indicate a malignant tumor with secondary infection. Nerve weakness and skin infltration are always associated with malignant tumors which have already infltrated the nerve or skin although the vice versa is not always true.

Major salivary glands are palpated, and secretions milked out to check fow, quantity, and quality of secretion. A turbid salivary discharge may indicate an infection, whereas reduced salivary fow could indicate either less secretion or obstruction to fow. Function of facial nerve should be checked and documented during parotid examination. On inspection submandibular gland swelling can be easily identifed and compared with the contralateral side; however the submandibular glands are bimanually palpated (Figs. 46.8 and 46.9).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.8** Clinical photo showing submandibular gland enlargement, right side

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.9** Bimanual palpation

Various diagnostic aids for investigating salivary gland diseases are as follows:

	- (a) Routine radiographs: It is useful only for diagnosing sialoliths and parenchymal calcifcations. Radiopaque salivary calculi in the gland or duct can be picked up on plain flms such as occlusal X-ray for submandibular gland and duct and a posteroanterior (PA) skull with blown-out cheeks for parotid calculi.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.10** USG of submandibular gland

Procedure: The duct orifce is enlarged using a lacrimal probe and cannulated with a 22 gauge cannula after infltrating local anesthetic (Fig. 46.11a, b). The selected dye is injected into the ductal system using a Luer lock syringe with gentle continuous pressure with simultaneous massage of the gland. Once the patient feels some discomfort, dye injection is stopped. X-rays are taken during the flling phase and emptying phase as well.

The X-rays show different patterns:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.11** (**a**, **b**) Sialography technique

©Association of Oral and Maxillofacial Surgeons of India

(h) Positron emission tomography (PET): Uptake of radiotracer fuorodeoxyglucose used with PET scans by salivary glands makes this diagnostic technique useful for salivary gland tumors. Although this is an expensive technique, measurement of metabolic activity makes it more reliable than CT and MRI scans. It can be used to diagnose recurrences, tumor hypoxia, and proliferation rates [15].

©Association of Oral and Maxillofacial Surgeons of India

#### **Fig. 46.13** CT scan showing parotid tumor

2. Histopathology: The gold standard of diagnosis for neoplasms will always be histopathology (HPE). However, as the major salivary glands are deeper structures, an FNAC (fne-needle aspiration cytology) is considered as a standard of care for diagnosis to avoid tumor seeding, which might follow an open biopsy. An open biopsy can be considered for minor salivary gland tumors or malignant tumors affecting major salivary glands with skin infltration, needing skin excision to achieve surgical clearance. HPE for salivary gland

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.14** MRI showing parotid tumor, right side

pathologies is very challenging, and hence diagnosing lesions on FNAC is more diffcult. It is important to distinguish benign and malignant pathologies on FNAC even if the exact malignant variant is missed, because except adenoid cystic carcinoma which has perineurial spread, the surgery doesn't change for any other malignant tumor variant.


#### **46.4 Non-neoplastic Diseases** (Table 46.5)

#### **46.4.1 Acute Bacterial Sialadenitis**

Parotitis (Fig. 46.15) occurs secondary to decreased salivary secretions, and various reasons are attributed.

**Table 46.5** Important terminologies in relation to salivary gland diseases

*Sialadenitis:* Sialadenitis is infammation of the gland parenchyma. It could either be suppurative (with pus) or nonsuppurative (without pus). It can also be classifed as acute, subacute, or chronic. *Sialodochitis:* This refers to infammation of the salivary gland duct. It may be associated with duct strictures and/or sialoliths.

*Sialectasis:* This refers to cystic dilatation of the ducts due to either a sialolith or ductal strictures. It is most commonly seen in parotid gland infections. It can occur due to any condition causing chronic infammation of the gland.

*Sialorrhea:* This refers to excessive secretion of saliva or drooling of saliva. It is most commonly seen in patients with cerebral palsy and neuro-degenerative disorders.

*Sialosis*: It is defned as an asymptomatic, non-neoplastic, noninfammatory parenchymal salivary gland disease which manifests as persistent painless bilateral salivary gland swelling, most commonly involving the parotid gland [16].

*Sialodochoplasty*: It is repair of the salivary gland duct usually by translocating the ductal opening.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.15** Parotitis left side

The common etiologic factors for parotitis are reduced salivary fow due to severe dehydration, in patients with debilitating diseases, old age, post-operative patients, post radiotherapy for head and neck cancers, poor oral hygiene leading to recurrent infection, mechanical obstruction to fow, compromised host resistance due to systemic illnesses like Diabetes Mellitus, renal failure, HIV, post transplant immunosuppresants. The drugs which induce systemic dehydration such as antihypertensives, diuretics, tricyclic antidepressants , phenothiazines, barbiturates, anticholinergics and betablockers also lead to reduced salivary fow rate [17].

©Association of Oral and Maxillofacial Surgeons of India

It may be retrograde contamination of salivary ducts and parenchymal tissues by oral microfora providing a bacterial source of infection. Stasis of salivary fow through the ducts and parenchyma may also promote acute suppurative infection. There is a higher risk of sialolith in the submandibular duct causing secondary suppurative sialadenitis (Fig. 46.16 showing submandibular sialadenitis).

#### **46.4.1.1 Clinical Features**


Routine blood count to rule out impending sepsis in addition to a plain radiograph or USG to rule out a sialolith in the duct is indicated. Sialography is contraindicated in cases of acute infections and also sialoliths. Aspiration might not yield frank pus.

#### **46.4.1.2 Management**

Treatment is managing underlying cause and adequate hydration and systemic antibiotics. If swelling doesn't subside with medical management in 2 days or shows an increasing trend, an incision and drainage is indicated. The cellulitic phase may not yield any frank pus, but toxic fuid is drained and it releases the pressure over the gland and prevents pressure necrosis of the gland parenchyma. Parotid space abscess has the tendency to spread into the pharyngeal spaces and cause respiratory distress and descending mediastinitis or burst into the auditory canal or TMJ and cause septic arthritis of the TMJ.

#### **46.4.2 Chronic Bacterial Sialadenitis** [18]

It is a recurrent sialadenitis with episodic relapsing swellings of the salivary glands, most commonly seen in the parotid gland. Salivary retention and stasis are the main predisposing factor. It might be preceded by an acute sialadenitis. Strictures may also form in the ducts leading to salivary stasis and eventually chronic sialadenitis. Generalized constitutional symptoms may be low grade, and salivary gland milking may yield scanty saliva. MRI is more specifc than CT scan.

#### **46.4.2.1 Management**

Management consists of short-term corticosteroids to eliminate glandular infammation followed by use of sialogogues to increase salivation and fush the debris. Sialoendoscopy can play a role in increasing the salivary fow.

The sialoendoscope is advanced slowly into the duct with continuous saline irrigation to help visualize the system and also dilating the strictures with help of the sialoballoon. This is followed up by placing a stent into the duct for 4 weeks.

Superfcial parotidectomy with facial nerve preservation can also be considered in case of chronic pain, provided imaging studies determine the involvement of superfcial lobe.

Chronic recurrent parotitis if left untreated may lead to benign lymphoepithelial lesion which can progress to lymphoproliferative disorders like non-Hodgkin's lymphoma, carcinoma, or pseudolymphoma.

#### **46.4.3 Obstructive Disorders** (Video 46.1)

Sialolithiasis or salivary calculi are most commonly seen in the submandibular gland and duct (Fig. 46.17a, b). Symptomatic calculi are much lesser in occurrence. Only those cases with superadded infection and infammation of the gland and duct result into pain.

#### **46.4.3.1 Etiology**

Salivary stasis is a major etiologic factor for formation of sialolith. The right-angle bend of the Stenson's duct where it pierces the buccinator and the 90° bend of the Wharton's duct at the border of the mylohyoid is the common location for sialoliths. They can also result from chronic sialadenitis. Systemic abnormalities of calcium metabolism are not associated with any increased risk of salivary stone formations. Gout is the only systemic illness known to predispose to salivary stone formation [19].

Salivary stasis changes the mucoid element of saliva to a gel framework for deposition of salts and organic substances creating a stone. Unknown metabolic phenomenon increases salivary bicarbonate content altering the calcium phosphate solubility and leading to precipitation of calcium and phosphate ions [20]. Wharton's duct is longer than the Stenson's duct, and the submandibular gland is situated at a lower level than the opening of the duct. Hence the duct has to follow an uphill, tortuous course and drain against gravity. So stagnation of secretions is more common than parotid gland.

In the submandibular gland, the calculus results in sialadenitis, whereas in the parotid gland, sialadenitis causes calculus formation. In the parotid gland, stones are most commonly located at the hilum or parenchyma, whereas submandibular sialoliths develop in the duct [21]. Sometimes typically the sialolith is expelled out of the gland through the duct and is seen at the duct orifce.

#### **46.4.3.2 Diagnosis and Management**

Sialography can be used for diagnosis of sialoliths but is contraindicated if the calculus is already diagnosed on plain radiographs. Smaller stones can be expelled out through the

**Fig. 46.17** (**a**, **b**) Left—Submandibular duct calculus (**a**). Right—Calculus after surgical removal (**b**). (**c**) Submandibular gland specimen showing calculus at the gene

duct opening using local massage, sialogogues, and adequate hydration. Larger stones are managed surgically according to its location in the duct and gland.

If the stone is palpable in the oral course of the duct, the duct is dilated with a lacrimal probe and cut open to retrieve the stone. The duct margins are sutured to the adjacent mucosa to avoid stricture formation. A stay suture can be placed around the duct proximal to the stone to avoid accidental pushing of the stone into deeper inaccessible part of the duct. In submandibular stones which are at the genu of the duct or deeper into the gland, a sialadenectomy is needed (Fig. 46.17c).

If the sialolith is posterior in the duct, a suture is placed behind the stone to prevent slippage of stone into the duct. The incision is placed over the duct to extract the stone, and the duct is left without suturing (Fig. 46.18a, b).

Sialodochoplasty is a procedure wherein the incised duct margins are sutured with adjacent mucosa leading to a translocation of duct orifce [22, 23].

In the case of parotid sialoliths, only those in the duct distal to the masseter muscle can be accessed transorally and removed. All deeper stones warrant a parotidectomy.

Extracorporeal shock wave lithotripsy and use of sialoendoscopy are newer modalities to manage sialoliths. Lithotripsy reduces calculi to small fragments that are then fushed out of the duct with spontaneous salivation or use of sialogogue [24]. The primary requirement for salivary stone lithotripsy is a functional gland which produces saliva which will clear the fragmented stone. A "gum test" which involves chewing of a sour gum can be done to test the functionality of the salivary gland. If the salivary secretions are normal, a visible swelling in the region of the gland will be noticed. If the test is negative, the patient cannot be taken up for lithotripsy.

#### **46.5 Viral Infections of Salivary Glands**

#### **46.5.1 Mumps**

Mumps is an acute nonsuppurative viral parotitis caused by paramyxovirus also known as epidemic parotitis. The term "mumps" is derived from the Danish word "Mompen" which means mumbling (like an old man) and describes the diffculty with speech because of infammation and trismus [17].

#### **46.5.1.1 Pathogenesis**

It is an endemic disease and spreads by airborne droplet dissemination. It has an incubation of 2–3 weeks followed by 3–5-day viremia. The virus localizes to the salivary glands,

**Fig. 46.18** (**a**, **b**) Technique of sialolith removal from submandibular duct

germinal tissues, and CNS [25]. The infection has a strong predilection for the parotid gland. It is highly contagious and occurs in children below 15 years of age with peak incidence being in the 4- to 6-year-old group of children [26]. Adults are rarely infected due to the immunity because of childhood exposure or due to the MMR vaccine [17].

#### **46.5.1.2 Clinical Features**

Prodromal symptoms include headache, myalgias, arthralgias, anorexia, and malaise prior to development of parotitis. It starts with an earache, pain around the gland, trismus, and dysphagia. Pain is exacerbated by salivary stimulation during meals. The parotid papilla may be infamed and puffy. Palpation of the gland reveals a swelling of the gland which may be tense, rubbery, and frm with non-pitting-type edema. The overlying skin is tensed and shiny without erythema or increased local temperature. Swelling lasts for 1–5 days and can displace the pinna. Seventy-fve percent cases result in bilateral involvement of parotid gland. However, it begins as a unilateral swelling and involves the contralateral gland after a period of 1–5 days [25].

Diagnosis is primarily clinical, but a blood count shows leukocytopenia with relative lymphocytosis. Serum amylase levels are also raised. It peaks during the frst week and starts declining in the second or third week and comes back to normal later [25].

"S" or soluble antibodies directed against the nucleoprotein core of the virus appear within the frst week of infection and peak within 2 weeks and disappear within 8–9 months. "V" or viral antibodies directed against the outer surface hemagglutinin appear several weeks after the "S" antibodies and persist at low levels for approximately 5 years following exposure. A fourfold rise in antibody titer is diagnostic of active infection. Mumps skin test is not useful in the diagnosis of acute infection because dermal hypersensitivity does not develop until 3 or 4 weeks following viral exposure.

#### **46.5.1.3 Treatment**

The disease is self-limiting, and treatment is primarily supportive such as rest, adequate hydration, antipyretics, and anti-infammatory medicines.

Live attenuated Jerry Lynn vaccine is given combined with measles and rubella as MMR vaccine after 12 months of age. Immunized population is less likely to get the disease but may be infected with a nonparamyxovirus.

#### **46.5.1.4 Complications**

Orchitis and oophoritis can occur as systemic manifestations and rarely lead to complete sterility. Mastitis has been associated with decreased lactation. Aseptic meningitis occurs in 10% of cases, and asymptomatic meningeal infammation is more common. Five percent patients are affected by acute pancreatitis, wherein serum lipase levels are also increased. Sensorineural hearing loss complicates 0.05–4% of patients and may be permanent and profound [26]. Tinnitus, aural fullness, and vertigo are associated symptoms, but they resolve over a period of few weeks. Additional complications include myocarditis, polyarthritis, hemolytic anemia, plasmacytosis, lymphocytic leukemoid reactions, and thrombocytopenia [12]. These conditions are self-limiting or resolve with or without steroid therapy.

#### **46.5.2 HIV Parotitis**

HIV-associated salivary gland disease is the term used to describe the diffuse enlargement of the salivary glands that affects HIV patients throughout all stages of the disease. In fact, HIV-SGD may be the frst presenting sign of HIV. Like most of the salivary diseases, the parotid gland is the most frequently affected. Clinically, HIV-infected individuals show reduced salivary fow rates. Parotid gland enlargement is reported to occur in 1–10% of the HIV-infected population. It is usually secondary to development of benign lymphoepithelial cysts within the parotid gland [25].

#### **46.5.2.1 Management**

Antiretroviral therapy with zidovudine, maintenance of oral hygiene, and use of sialogogues form the mainstay of management.

#### **46.6 Noninfectious Infammatory Diseases**

Mikulicz' disease and Sjögren's syndrome are closely related to each other and are autoimmune in origin, wherein the salivary tissue itself becomes antigenic [27].

#### **46.6.1 Mikulicz' Disease**

#### **46.6.1.1 Clinical Features** [28]

Middle-aged females are affected commonly. It behaves like an infammatory as well as a neoplastic disease. Presenting symptoms may be diffuse, poorly outlined, unilateral or bilateral enlargement of the parotid or submandibular glands with an occasional increase or decrease in size of the swelling. There is mild local discomfort, occasional pain, and xerostomia. Fever, upper respiratory tract infection, tooth extraction, or some other local infammatory disorder may precede the disease. Sometimes the lacrimal glands may be enlarged. FNAC can help diagnose the condition.

#### **46.6.1.2 Management**

Mild cases once diagnosed do not warrant any treatment. In some cases, the swelling might regress spontaneously. Persistent cases can be managed by sialadenectomy [28].

#### **46.6.2 Sjögren's Syndrome**

Sjögren's syndrome or Sicca syndrome is a chronic autoimmune disorder of the exocrine glands involving multiple extraglandular sites and can even evolve into a lymphoid malignancy. Sjögren's syndrome shows a triad of symptoms—keratoconjunctivitis sicca, xerostomia, and a systemic disease, usually but not always rheumatoid arthritis. Primary Sjögren's syndrome also known as Sicca complex presents with only dry eyes and dry mouth. Secondary Sjögren's syndrome has in addition to the above features systemic manifestations such as systemic lupus erythematosus, polyarteritis nodosa, polymyositis or scleroderma, and rheumatoid arthritis [28].

Arthritis is the most frequent frst complaint, followed by ocular complaints and then xerostomia which leads to diffculty in chewing and swallowing, sore mouth, recurrent dental caries, and fungal infections in the oral cavity. The tongue appears bald with loss of fliform papillae and fssuring of tongue. The saliva is usually cloudy due to pus and abnormally viscous due to gel-like consistency. Parotid gland enlargement is seen in 25–66% cases of primary Sjögren's syndrome but is uncommon in secondary cases. Xeropthalmia leads to chronic irritation and destruction of the corneal and bulbar conjunctival epithelium, referred to as keratoconjunctivitis sicca. The patient complains of redness, itchiness, or burning sensation in the eye, rope-like secretions, dryness, and a foreign body sensation in the eye and may not be able to tolerate smoke, air draft, or light [27].

Schirmer's test is used to confrm lacrimal secretions. Patients complain of easy fatigue, general malaise, lowgrade fever, myalgias, and arthralgias. Respiratory tract symptoms range from dry cough due to xerotrachea to dyspnea due to interstitial disease or even airway obstruction. High-resolution CT scan shows bronchial and peribronchial thickening, whereas transbronchial biopsies show bronchiolar lymphoid infltrates and follicular bronchiolitis [29]. Sensorineural hearing loss is associated with Sjögren's syndrome in 21–46% of cases [30]. Dysphagia results from drying of the pharynx and esophagus. Other complications include renal disease, Raynaud's disease, infammatory vascular disease, peripheral sensory or sensorimotor polyneuropathy or mononeuritis multiplex, skin dryness, vasculitis, and frequent allergic reactions. Labial salivary gland biopsy is used as a means of assessment of salivary pathology in Sjögren's syndrome.

#### **46.6.2.1 Management**

Xerostomia and keratoconjunctivitis sicca are managed by use of 0.5% methylcellulose artifcial saliva and tears. Preventive dental care and fuoride application and maintenance of general hygiene are necessary. Eye patching and boric acid ointment can be used for corneal ulcers. Pilocarpine hydrochloride can be used as a secretagouge for management of xeropthalmia and xerostomia. Systemic corticosteroids can be used for systemic complications such as vasculitis, glomerulonephritis, and interstitial lung disease.

#### **46.6.3 Mucoceles** (Video 46.2)

Mucous retention cyst arises from ductal obstruction in a minor or accessory salivary gland due to traumatic severance of the duct due to biting of the lips, cheeks, and tongue or due to injury due to lip pinching during extraction. Majority of cases are an extravasation type of cysts which result from collection of salivary secretions in the soft tissues due to traumatic injury to the gland or duct. Lower lip was affected in 44–79% of cases. It occurs in any age with no gender predilection [31].

#### **46.6.3.1 Clinical Features**

Superfcial lesions appear like a circumscribed, raised vesicle with a bluish translucent hue due to the thin overlying mucosa. However, deeper lesions being covered by normal mucosa have a normal color and texture. Mucoceles may get traumatized and rupture spontaneously and may recur later.

#### **46.6.3.2 Management**

Surgical excision of the mucocele along with a few normal minor salivary glands is the procedure of choice. Care should be taken to avoid creation of any other partially transected minor salivary glands which might give rise to the recurrent mucocele.

Mucocele can be excised by giving an elliptical incision around the lesion and closure (Fig. 46.19a–d), [32] or as the case requires, an incision may be given over the mucocele; lesion can be excised carefully without rupture and closure attained (Fig. 46.19e–h).

Huang I et al. [33] recommended use of carbon dioxide laser vaporization to treat the lower lip mucocele with good results and less complications.

#### **46.6.4 Ranula**

Ranula is a mucocele arising from the sublingual salivary gland in the floor of the mouth (Fig. 46.20). It presents as a large blue, tense vesicle in the floor of the mouth. The appearance is of that of a frog's belly, hence the term ranula (frog belongs to genus Rana). It is firm on palpation. The cyst is usually present above the mylohyoid curtain, but when it presents in the upper part of the neck, it is called as a "plunging ranula." Plunging ranulas may grow to a sufficient size so as to compromise respiration and swallowing and may also extend into mediastinum [32].

#### **46.6.4.1 Management**

Excision of the ranula and entire sublingual gland through a transoral approach is management of choice taking care to avoid damage to the lingual nerve. The incision is made through the mucosa in the lingual fold from the second molar to canine tooth. Blunt dissection is done up to the mylohyoid muscle. The gland is dissected free from the surrounding soft tissues and the Wharton's duct. The gland can be retracted using holding sutures, and blunt dissection is carried out till the lingual nerve is identifed as it crosses the Wharton's duct. The gland is delivered once it is dissected free from the entire surrounding soft tissues taking care to prevent damaging the submandibular duct and lingual nerve [34].

Marsupialization can be used as an alternative modality wherein the ranula is deroofed and the mucosa sutured to the cystic lining followed by open packing of the cyst and sequentially reducing the size of the pack till it heals completely.

**Fig. 46.19** (**a**)–(**d**) Figure showing surgical removal of mucocele by elliptical incision. (**e**)–(**h**) Figure showing excising mucocele by incision directly over the lesion

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.19** (continued)

Higher recurrence rate (61–85%) has been reported with simple marsupialization and ranula excision. To lower the rate of recurrence, total sublingual excision is the treatment of choice [35].

Kono et al. [36] recommended an injection of sclerosing agent, OK-432 (Picibanil), as a safe and effective method of treating intraoral ranulas. The number of injections used was 1–4 (mean 1.70) in their study.

#### **46.7 Salivary Gland Tumors**

#### **46.7.1 Etiology**

Although no specifc etiology has been attributed to occurrence of salivary gland tumors, its association with radiations, viruses, hormones, lifestyle, or occupation and like factors can't be denied.


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.20** Ranula in the foor of the mouth


#### **46.7.2 Incidence**

Salivary gland tumors occur rarely both among Indian population and around the world. Incidence of benign and malignant salivary gland tumors in major portion of the world ranges from 1 to 2 cases per 100,000 people per year [41]. There is no specifc predilection of occurrence of these tumors in any particular gender, although Warthin's tumor is more common in males and acinic cell tumor in females. Site wise incidence varies for both benign and malignant tumors. Seventy-fve to eighty percent of benign tumors occur in the parotid glands, 5–10% in submandibular glands, and only 1–2% in sublingual glands. Malignant tumors are more common in sublingual glands (80%) and least in parotid glands (17–20%). Benign tumors affect a mean age group of 40 years, and malignant tumors affect an age group of 55 years. Both benign and malignant tumors by large resemble each other clinically. Hence, histopathologic examination is pivotal to establish a correct diagnosis.

#### **46.7.3 TNM Staging of Salivary Gland Tumors According to American Joint Commission on Cancer (AJCC) 2002** [42]

	- N2a: The cancer has spread to a single lymph node on the same side as the primary tumor and is larger than 3 cm but smaller than 6 cm.
	- N2b: The cancer has spread to more than one lymph node on the same side as the primary tumor, and none measures larger than 6 cm.
	- N2c: The cancer has spread to more than one lymph node on either side of the body, and none measures larger than 6 cm.

#### **46.7.4 Classifcation of Salivary Gland Tumors**

Salivary gland tumors were frst classifed by WHO in 1972. It was later modifed in 1991 wherein the term "tumor" was replaced by "carcinoma" to denote acinic cell carcinoma and mucoepidermoid carcinoma [43]. It was further revised in 1997, and a greater number of entities of adenomas (myoepithelial adenoma, basal cell adenoma, canalicular adenoma) and carcinomas (acinic cell carcinoma, mucoepidermoid carcinoma, polymorphous low-grade adenocarcinoma, salivary duct carcinoma, myoepithelial carcinoma) were redefned with emphasis on the prognosis and therapy [44]. A revised classifcation was put forth by WHO in 2005 also. The latest classifcation of WHO which was given in 2017 consisted of the following changes:


#### **46.7.5 Pleomorphic Adenoma**

"Pleomorphic adenoma" suggested by Willis closely resembles the unusual histologic pattern of the lesion [28]. The tumor derives its name from the Greek words Pleos = many and morphus = form because of the heterogeneous nature of its histologic appearance [46].

#### **46.7.5.1 Clinical Features**

Most frequently found in the superfcial lobe of the parotid gland, it presents as a frm, slow-growing asymptomatic mass which is smooth, rounded, lobular, and mobile with a rubbery consistency causing ear lobule to be raised (Fig. 46.21a). If the tumor involves both the superfcial and deep lobes of parotid, it is classically referred to as dumbbell tumor. Incidence of the tumor except those found in the pharynx is more in females than males, and they are often seen in the fourth and ffth decade. A bilateral tumor occurrence rate is estimated at 1 in 40,000 [47].

**Table 46.6** Revised classifcation of salivary gland tumors (2017) [45]


They are encapsulated and do not show fxity to the deeper tissues or the overlying skin in major salivary gland tumors, which can be confrmed on an MRI (Fig. 46.21b), but in the case of the minor salivary glands of the palate, it may appear to be fxed to the underlying palatal bone but does not invade or erode the bone. Pain is uncommon but 50% patients experience a pressure sensation. Accumulation of mucus can occur so that elastic swellings or frankly fuctuant cysts may form in the tumors.

In the case of the submandibular gland, palpation of the mass both extraorally and bimanually helps in localizing it and differentiating it from a lymph node, but FNAC is always needed to differentiate it from sialadenitis.

#### **46.7.5.2 Histopathology** [48]

On light microscopy morphologically complex and diverse cellular elements are seen. Both epithelial and myoepithelial elements are present. Based on cellular types, Foote and Frazel [49] have classifed pleomorphic adenomas as follows:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.21** (**a**) Parotid tumor showing elevation of ear lobule (pathognomonic sign). (**b**) MRI axial view showing the tumor

#### **46.7.5.3 Management**

Surgical excision is the treatment of choice. Historically, enucleation was practiced which resulted in inadequate surgery and recurrences [50]. Superfcial parotidectomy is the most widely accepted technique in the treatment of pleomorphic adenomas in the superfcial lobe of the parotid gland, and total gland excision with facial nerve preservation is carried out. Tumors of the submandibular gland are usually contained within the gland, and their resection is usually confned to the gland and surrounding fat or lymph nodes until the neoplasm is a malignant and invasive tumor. As with the parotid gland, most neoplasms are asymptomatic. Small palatal pleomorphic adenomas usually cause pressure resorption of the palate but do not invade the bone. A disk of palatal mucosa is outlined well clear of the visible swelling because the tumor is fattened owing to the toughness of the palatal tissues. The tumor along with the periosteum of the palate is excised in continuity with each other. In case the pleomorphic adenoma invades the palate or proliferates into the foor of the maxillary sinus, a partial maxillectomy or total maxillectomy depending on the extension of the tumor has to be performed.

Although pleomorphic adenoma is a benign tumor, it may cause problems in clinical management due to its tendency to recur and risk of malignant transformation.

#### **46.7.6 Monomorphic Adenoma**

The WHO classifcation subdivides the monomorphic adenomas into three groups [45]:


A number of other classifcations of monomorphic adenomas have been put forth, but there is no unanimity. Two main histologic patterns have evolved:


#### **46.7.7 Warthin's Tumor**

Warthin's tumor, also known as papillary cystadenoma lymphomatosum and adenolymphoma, is the second most common benign tumor of the salivary glands, around 5% of neoplasms [51].

It was frst described by Hildebrand in 1895 as a form of congenital cyst of the neck. It is known as Warthin's tumor in recognition of the pathologist who frst described it in the USA in 1929. He described two cases and also coined the term papillary cystadenoma lymphomatosum [52].

#### **46.7.7.1 Clinical Features**

The majority of the tumors arise in the parotid gland, more often bilaterally, in the elderly and occurs in the ffth and sixth decades of life. A predilection for male sex is seen, more in Caucasians. Both tumors do not occur simultaneously but are metachronous in their manifestation. A concept of multicentric and multifocal disease has been put forth to explain this. It is a solitary, nodular, slowly enlarging swelling, most commonly located in the inferior pole of the parotid next to the angle of the mandible. It varies from moderately frm to fuctuant on palpation and is asymptomatic. It is not as discrete as the mixed tumor. Very few patients present with complain of pain, pressure, or rapid increase in the tumor size. Scintigraphy may be helpful due to its increased uptake of technetium-99m pertechnetate. It appears as a smooth-margined, radiopositive "hot" nodule in contrast to the mixed tumors, nonfunctioning malignant tumors, and metastatic tumors which appear as a "cold" nodule in scintigraphy. Positive scintigraphy with 123I is indicative of Warthin's tumor but may also signify presence of ectopic thyroid or metastatic thyroid tumor.

#### **46.7.7.2 Management**

Surgical removal is the established treatment for Warthin's tumor. As the tumor is superfcial in the parotid gland, it is easily removed with minimal loss of glandular function and with preservation of the facial nerve.

Treatment philosophies given are:


Local excision of the tumor is preferred to enucleation of the tumor because lymph nodes at the posteroinferior part of the gland cannot be cleared by enucleation. Preoperative diagnosis of Warthin's tumor must be confrmed by coordinating the clinical fndings with imaging and fne-needle aspiration biopsy reports before local excision is carried out. If there is associated chronic obstructive parotitis, superfcial parotidectomy is essential. Similarly, if the tumor is located in front of the ear, a superfcial parotidectomy is the treatment of choice.

#### **46.7.8 Oncocytoma**

An oncocytoma is a tumor characterized by large epithelial cells, i.e., oncocytes that contain a brightly eosinophilic, granular cytoplasm. The oncocyte is derived from the Greek word "onkousthai" meaning swollen or enlarged and was described in 1897 by Schaffer who observed this tumor in ductal and acinar elements of salivary glands in the tongue, pharynx, and esophagus. Jaffe was the frst to introduce the term oncocytoma [53]. However, he had termed Warthin's tumor as oncocytoma. The other terminologies used to describe this tumor are oxyphilic adenoma and acidophilic adenoma.

#### **46.7.8.1 Clinical Features**

There is no race predilection for occurrence of this tumor. Oncocytoma is predominantly a tumor of the major salivary glands, parotid being the most common. Bilateral occurrence is also known. Among minor salivary glands, which are rarely affected, palatal mucosa followed by buccal mucosa and tongue is affected.

The oncocytoma is a small benign lesion which generally does not attain a great size. It most frequently presents as an indolent, single, often multi-lobulated, frm, solid, and mobile mass in the superfcial lobe of the parotid gland. It can also be located in the deep lobe of the parotid gland and may be insinuated between the branches of the facial nerve. However, it does not cause any symptoms of pain or paresthesia unless the branches of the facial nerve are compromised. Tumor size varies with the duration of the lesion but generally does not increase beyond 4.0 cm. Intraoral tumors do not exhibit any special characteristic diagnostic features. However, their overlying mucosa may become ulcerated due to trauma [53].

#### **46.7.8.2 Management**

Partial parotidectomy with facial nerve preservation whenever possible is the treatment of choice. It ensures complete removal of the tumor and reduces the rate of recurrence. Curettage or simple enucleation of the tumor is to be avoided to avoid recurrence. Complete sialadenectomy is the treatment of choice in cases of submandibular gland oncocytomas. In the case of minor gland tumors, local excision of the tumor with a margin of normal tumor-free tissue is carried out. Radiation therapy after surgery has been tried but it has shown to be ineffective.

#### **46.7.9 Basal Cell Adenoma**

It was frst reported as a separate entity by Kleinsasser and Klein in 1967 [28].

#### **46.7.9.1 Clinical Features**

Basal cell adenomas occur between the third and ninth decade, but the peak incidence is in the sixth decade with a slight male predilection of 5:1 [28]. They are clinically indistinguishable from mixed tumors and occur in the superfcial portion of the parotid gland. They are slow-growing, painless, round or ovoid, well-circumscribed, and freely mobile masses with a smooth-surfaced capsule and a soft to moderately frm consistency. They may be mistaken for a hyperplastic lymph node because of their encapsulation, size, and color.

Clinically basal cell carcinoma of skin, ameloblastoma, pleomorphic adenoma, and adenoid cystic carcinoma can be considered in the differential diagnosis.

On the basis of histopathologic appearance, they may be divided into four subtypes:


#### **46.7.9.2 Management**

Surgical excision with a suffcient clear margin of normal tissue is the treatment of choice.

#### **46.7.10 Canalicular Adenoma**

#### **46.7.10.1 Clinical Features**

It is seen between the fourth and ninth decade, highest incidence being in the seventh decade with a female/male ratio of 1.7 to 1.0 and a higher incidence in Caucasians. It is seen more commonly in the minor salivary glands of the lip and cheek and rarely affects the major salivary gland [54].

It presents as a non-ulcerated, painless, mobile nodule that exhibits slow growth unless it is traumatized, wherein there is presence of ulceration. Clinical appearance is similar to that of a mucocele [54]. The overlying mucosa may be normal colored or bluish.

In the case of upper lip lesion, a sialolith, mucocele, mucous retention cyst, and pleomorphic adenoma can be considered in the differential diagnosis.

#### **46.7.10.2 Management**

Surgical excision, enucleation, or limited extracapsular excisions have been used as treatment modalities in these tumors with success.

#### **46.7.11 Sialadenoma Papilleferum**

First described by Abrams and Finck in 1969, it was termed sialadenoma papilleferum because of its histologic similarity to syringocystadenoma papilleferum of skin adnexal origin [55].

#### **46.7.11.1 Clinical Features**

Sialadenoma papilleferum presents as a subcentimetric, asymptomatic, exophytic, papillary surface lesion which can be confused with squamous papilloma. The most common site of occurrence is the minor salivary glands at the junction of soft and hard palate with the tumor located on one side of the midline. This tumor occurs at an average age of 56 years, cases being reported from 2 years to 87 years. Male predilection is seen in the ratio of 1.5 to 1. However, there is no racial predominance [55].

Clinically it resembles a squamous papilloma, and a differential diagnosis of verrucous carcinoma or a warty dyskeratoma needs to be considered.

#### **46.7.11.2 Management**

Being small, these tumors are easily excised usually with a clinical diagnosis of a squamous papilloma. However, recurrence is rare.

#### **46.7.12 Inverted Ductal Papilloma**

Inverted ductal papilloma is a rare tumor and was frst described by White et al. in 1982 when they reported four cases [56].

#### **46.7.12.1 Clinical Features** [56]

It occurs as a frm, asymptomatic, discrete nodule of 1–1.5 cm beneath the normal mucosa which in some cases may be contiguous with a small surface pore. The mean age of occurrence is 50 years without any sex predilection. The sites usually involved are the lower lip and buccal vestibular mucosa in descending order with occasional cases reported in the upper lip, foor of mouth, and soft palate.

#### **46.7.12.2 Treatment and Prognosis**

It is treated by simple surgical excision as it is not known to recur.

#### **46.7.13 Intraductal Papilloma**

It is a rare tumor. These tumors present as asymptomatic, submucosal swellings that vary in size from less than 1 to 1.5 cm in the minor salivary glands. The ages of patients range from 29 to 77 years, with a mean age of 54 years. Men and women are equally affected.

#### **46.7.13.1 Treatment and Prognosis**

Excision is curative, and these tumors are not known to recur. In case the tumors are small, all types of papillomas of the minor salivary glands, including intraductal, inverted, and sialadenoma papilliferum, can be excised in the dental offce or the clinic under local anesthesia [55].

#### **46.7.14 Mucoepidermoid Carcinoma**

Mucoepidermoid carcinoma is the most common malignant salivary gland neoplasm. They are classifed as grade I (low grade) which are well differentiated, grade II (intermediate grade) which are moderately differentiated, and grade III (high grade) which are poorly differentiated tumors.

#### **46.7.14.1 Clinical Features**

Mucoepidermoid carcinomas occur more commonly in the minor salivary glands with a female predilection [57]. It occurs as a painless, circumscribed, mobile solitary enlargement of the body or tail of the parotid or the submandibular region with over a year duration generally. Pain, facial paralysis, and fxation to the overlying skin are usually suggestive of high-grade lesions [57]. Minor salivary gland lesions present as a bluish or red-purple, fuctuant, smooth-surfaced mass that is often clinically mistaken for a mucocele or hemangioma [57]. Large lesions at the base of the tongue or in the oropharynx may cause dysphagia. Aggressive tumors show ulceration. Numbness of the teeth may occur when the bone is involved. Histopathologically, mucoepidermoid carcinomas are graded as low-grade, intermediate-grade, and high-grade carcinomas. They are generally partially encapsulated and don't show adequate circumscription.

#### **46.7.14.2 Management**

Complete, adequate, and radical surgical excision is the treatment of choice for all grades of mucoepidermoid carcinomas [58]. In the case of stage I and stage II mucoepidermoid carcinomas of the parotid gland, conservative excision with preservation of the facial nerve, if possible, is recommended. The affected submandibular gland should be removed entirely. Radical neck dissection is performed in patients with clinical evidence of cervical node metastasis and is considered in any patient with a T3 lesion. In the case of facial nerve involvement, total parotidectomy with facial nerve sacrifice up to histologically tumor-negative nerve trunk is done. The 5-year disease-free rate in patients receiving this aggressive treatment was about 60% [58].

Treatment of minor salivary gland mucoepidermoid carcinomas entails a wide surgical excision with the bone if involved, to achieve a negative margin, and the wound is left to heal secondarily [59]. For small low-grade tumors in the absence of bone involvement, wide excision down to periosteum with 1 or 2 cm tumor-free lateral margins is adequate therapy [59]. High-grade and advanced stage tumors must be treated aggressively at any site. The overall recurrence rate of mucoepidermoid carcinomas is approximately 25%. Better survival is seen among younger patients and among females. Tumors in the submandibular gland and in the base of the tongue generally have a poorer outlook than those at other major and minor salivary gland sites. Also invasion into bone signifes a poorer prognosis. Survival is closely related to the clinical stage and the histologic grade.

#### **46.7.15 Adenoid Cystic Carcinoma**

Adenoid cystic carcinoma (ACC) is a highly aggressive, destructive, and clinically unpredictable tumor of the head and neck region [60]. The other terms used for ACC used in the past are cylindroma and adenomyoepithelioma. Foote and Frazell [49] proposed the currently accepted term adenoid cystic carcinoma in their classic paper in 1953 and in their fascicle on major salivary gland tumors in 1954.

#### **46.7.15.1 Clinical Features**

Adenoid cystic carcinoma occurs in adults between 50 and 70 years of age with equal prevalence in males and females [61]. The most frequent locations of this tumor are the parotid, submandibular, and palatal salivary glands [62]. They are only rarely observed in the sublingual gland [61].

Clinically adenoid cystic carcinoma manifests in the major and intraoral accessory salivary glands as a slowgrowing swelling or mass. Pain and fixation to skin as well as surrounding deeper structures generally occur during the course of tumor growth. An ominous feature of adenoid cystic carcinoma of the parotid gland is paralysis of the facial nerve. Radiographic examination is valuable in assessing the extent of osseous destruction. Symptoms may have been present for months or years and are generally of longer duration than those associated with squamous carcinoma, which is the most frequent malignancy of this location. Adenoid cystic carcinomas of the maxillary antrum, nasal cavity, and ear canal produce symptoms of pain, obstruction, and deafness, respectively.

Histopathologically, ACC are classifed into cribriform pattern, tubular pattern, and solid pattern. A major microscopic feature in most adenoid cystic carcinomas is the propensity for the tumor to involve peripheral nerves, reported to occur in 20–80% of the patients. Although perineural invasion is characteristic of adenoid cystic carcinoma, it is not unique to the tumor.

#### **46.7.15.2 Management of Adenoid Cystic Carcinoma**

Complete excision like all other tumors is the treatment of choice. Elective regional lymph node dissection is not indicated, because distant metastasis is more common than cervical (regional) node involvement. According to Maciejewski et al., radical surgical excision with histologically proven negative margins with postoperative radiotherapy for all cases should be the treatment of choice. Lymph node dissection is recommended only in cases of histologically proven positive lymph nodes [60]. A frozen section diagnosis to achieve tumor-free safe margins is necessary to specifcally look for safe perineural margins because ACC is known to spread quickly along the nerve.

The slow biologic growth of adenoid cystic carcinoma along with a late metastasis of the disease results in relatively favorable 5-year survival rates. Factors that indicate a poor prognosis include failure to achieve clear margins at frst surgery, a solid pattern histologically, recurrent disease, and distant metastasis [63].

In a study by Witten et al., local recurrences have been seen in almost 32% of the cases [63]. The risk of distant metastasis is also high, approximately 40%, and can occur in less than 8 years after treatment.

#### **46.7.16 Clear Cell Carcinoma**

Clear cell neoplasms of salivary glands have been classifed as both adenomas and carcinomas [64].

#### **46.7.16.1 Clinical Features**

It occurs predominantly in the palatal minor salivary glands followed by parotid and submandibular glands without any sexual or racial predilection. It occurs between the ages of 18 and 86 years, mean 56 years. Clinical manifestation is of a swelling similar to other tumors. It may be confused with mucoepidermoid and acinic cell carcinoma as well as metastatic renal cell carcinoma. A positive reaction to mucicarmine would preclude the possibility of renal cell carcinoma.

#### **46.7.16.2 Management**

Due to their infltrative growth and the incidence of recurrence and regional lymph node metastases, it is appropriate to consider them low-grade adenocarcinomas. Hence surgical treatment is the mainstay of management.

#### **46.7.17 Epithelial-Myoepithelial Carcinoma**

The epithelial-myoepithelial carcinoma of intercalated duct origin is a rare biphasic type of low-grade salivary gland carcinoma that constitutes less than 1% of salivary gland neoplasms.

#### **46.7.17.1 Clinical Features**

It occurs more commonly in females around 60–70 years of age. Parotid gland is the most frequently affected [65]. Patients present with an asymptomatic or painful salivary gland swelling with a history of steady increase in size over an extended period of time and may also present with facial paralysis [66]. In patients with maxillary involvement, nasal obstruction and facial deformity may be the presenting complaints. Differential diagnosis includes pleomorphic adenoma, acinic cell adenocarcinoma, adenoid cystic carcinoma, mucoepidermoid carcinoma, sebaceous carcinoma, and oncocytoma.

#### **46.7.17.2 Management**

Surgery is considered the primary mode of treatment. Total parotidectomy with facial nerve preservation is advocated for tumors in the parotid gland unless the nerve is involved by the tumor. Recurrences and distant metastasis are a known complication.

#### **46.7.18 Carcinosarcoma**

Carcinosarcoma, also known as true malignant mixed tumor, shows malignant cells in both the stromal and epithelial components [67]. When these tumors metastasize, both components metastasize together.

#### **46.7.18.1 Clinical Features**

Carcinosarcomas are rare tumors with an average incidence of 0.4% in major salivary glands and 1% in minor salivary glands. It occurs between 25 and 85 years of age (average 58.5 years) with the frequency of occurrence being more in parotid than submandibular gland and then minor glands in palate and tongue [67].

It presents as an enlarging mass with a rapid increase in size and may be associated with pain and facial nerve paralysis. Rarely, patients present with metastases or experience diffculty in swallowing or breathing. A patient with a central nervous system metastasis has been reported to present with headaches [67].

#### **46.7.18.2 Management**

The data available is insuffcient to recommend one type of therapy as defnitive. However radical surgical excision, together with radiation therapy and lymph node dissection for palpable disease, seems to be the most prudent form of therapy. Radiotherapy as the only means of therapy has not proved effective. Tumor metastasis is most frequent to the lungs followed by hilar and cervical lymph nodes. Distant metastasis is also rarely found [67].

#### **46.7.19 Undiferentiated Carcinomas**

This group includes three distinct entities:


#### **46.7.20 Squamous Cell Carcinoma**

The diagnosis of primary squamous cell carcinoma is limited to the major glands because distinction between possible minor salivary gland primary tumors and those originating from mucosal surface epithelium is generally not possible.

#### **46.7.20.1 Clinical Features**

It occurs between 7 and 95 years of age, the mean age being 60.5 years with a male predilection of 2:1. Parotid gland is the most commonly involved followed by submandibular and sublingual glands [68]. It presents as an asymptomatic mass with occasional pain and facial nerve palsy. This tumor often replaces the entire gland with fxation to underlying structures and skin.

Ductal squamous metaplasia, high-grade mucoepidermoid carcinoma, and lymphoepithelial carcinoma should be considered in the differential diagnosis of squamous cell carcinoma of the salivary gland.

#### **46.7.20.2 Management**

Surgical management is the mainstay of treatment. Parotidectomy with or without facial nerve preservation depending on the case is needed for parotid tumors. Submandibular sialadenectomy is needed for submandibular gland tumors. A neck dissection is done in clinically positive necks at the slightest suspicion. Locoregional failure is the most signifcant problem, and hence a composite resection in larger submandibular malignancies might be needed. Postoperative radiotherapy when combined with surgery may improve the locoregional control [68].

#### **46.8 Surgical Management of Parotid Tumors** (Video 46.3)

The following procedures are performed:


#### **46.8.1 Skin Incisions for Parotidectomy** [69]

The ideal incision should combine good exposure with the best ultimate cosmetic result. This part of the procedure is common to all the resection procedures unless skin is being excised because it is involved by the tumor.

Gutierrez (1903)—The incision had a temporal extension, a preauricular component, and a limb extending onto the neck in one of the skin creases (Fig. 46.22). The chief drawback of this incisions was esthetics in case of development of a keloid.

Redon and Vaillant and Laudenbach—The incision line is similar to that proposed by Adson (Fig. 46.23).

Adson and Ott have described a "Y"-shaped incision with a preauricular part, a postauricular part, and a cervical incision line that splits off from the site of union of the frst two branches (Fig. 46.24). The advantage of this incision is improved esthetics because it lacks a temporal incision line, but the drawback is that it impairs dissection. Also, one section of the incision is located in the carotid region.

Samengo (1961)—The incision has a preauricular, a postauricular, and a neck extension in the incision line (Fig. 46.25).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.22** Gutierrez incision

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.23** Redon and Valliant and Laudenbach incision

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.24** Adson and Ott incision

Appiani (1967)—The incision within the lower portion of the scalp is hidden by the hair instead of the vertical incision line. The beneft of this incision is better esthetics. However, the temporal extension of this incision is short, and this impairs access to the anterior portion of the gland (Fig. 46.26).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.25** Samengo incision

Ferreria JL et al. [69] modifed Appiani's incision by extending the temporal incision line but not beyond the hairline. It provides a better access to the anterior portion of the parotid gland without compromising esthetics. Also, the angles are rounded off where the incision line changes direction reducing dehiscence and salivary fstula formation.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.26** Appiani's incision

Farrior et al. recommended a single curved incision 1.5–2.0 cm below the mandible and extending over the mastoid region 1.5 cm behind the postauricular crease in

children. The preauricular crease used in adults is avoided because of the superfcial location of the facial nerve and possibility of facial nerve damage during fap elevation [68] (Fig. 46.27).

The Blair incision is an S-shaped incision that starts from the preauricular region and extends in the neck. The major disadvantage of the Blair incision is a visible scar in the neck that may cause facial or cervical disfgurement causing patients dissatisfaction [70].

The standard incision is a modifed Blair incision (Fig. 46.28) wherein the skin incision is placed in a preauricular crease and doesn't extend beyond the level of the root of the helix. It extends inferiorly around the ear lobule over the mastoid tip. It gently curves down along the sternocleidomastoid muscle and then slightly forward in a natural crease in the upper neck [71].

A facelift incision can be used to avoid the hollowing after parotidectomy, and the defect can be flled with SMAS advancement fap (Bananno and Casson [72], 1992). However, the SMAS-lifting technique is not a routine procedure for many surgeons [73].

Rai A et al. [74] advocated use of posterior belly of the diagastric muscle fap (PBDMF) for reconstruction of the surgical defect after superfcial parotidectomy. PBDM inserts very close to stylomastoid foramen, and it is considered as an

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.27** Modifed Blair incision in pediatric patient

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.28** Modifed Blair incision in adults

important landmark in the identifcation of facial nerve main trunk. The harvesting and dissection of PBDMF becomes easier as it lies in the surgical site, and no extra incision is required to harvest it. It can be used in thin and young patients with good esthetic results.

#### **46.8.2 Identifcation of the Facial Nerve**

This has been previously described in the section on applied anatomy of the parotid gland.

#### **46.8.3 Surgical Management**

The selection of type of procedure for surgical management of parotid tumors depends on the site, size and clinicohistopathologic features. The various procedures are described briefy as under:

#### **46.8.3.1 Local Excision of Parotid Gland**

This technique is used for management of a small tumor in the tail of the parotid gland less than 3.5 cm. Due to small tumor size, most of the functional gland along with the duct can be preserved.

#### **46.8.3.2 Parotidectomy with Preservation of the Facial Nerve** [75]

After marking the incision, infltration is usually done with Saline Plus 1 in 200,000 parts adrenaline instead of lignocaine with adrenaline to avoid blocking the facial nerve fbers. In case lignocaine is used, care should be taken to avoid deep injections. Care should be taken to avoid extending the incision too far posterior beneath the ear lobe to avoid persistent edema [75].

The incision in the neck crease is deepened to raise a fap in the subplatysmal plane (Fig. 46.29). The greater auricular nerve is identifed and preserved. It branches over the surface of the gland where two or more branches should be followed and then divided.

Once the deep fascia has been identifed, rest of the wound is deepened to this level and skin refected forward from it. At the zygomatic bone, some subcutaneous fat should be left on the fascia to avoid damaging the branches of facial nerve which lie more superfcially as they emerge from the upper part of the parotid. The main trunk of the nerve is found by frst separating the lower pole of the gland from the anterior border of the sternomastoid and then from the mastoid process and the cartilaginous part of the external auditory meatus (Fig. 46.30). The wound is deepened anterior to the margin of the sternomastoid, and the lower pole is dissected free as far forward as the external jugular, uncovering the posterior belly of the digastric muscle. The vein should not be divided and tied at this stage because this will increase the venous engorgement of the parotid and the ooze from its divided tissues.

Neither should the lower pole be raised further forward because the branches of the facial nerve often pass superfcial to the vein and emerge from the gland anterior to it. The parotid is retracted forward as the dissection proceeds and

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.29** Flap raised in the sub platysmal plane exposing the superfcial surface of tumor

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.30** Representing facial nerve main trunk

the pointed, lower extremity of the tragal cartilage (pointer) will be uncovered. Where possible, the edge of the fascia should be raised and the underlying tissue separated by blunt dissection until the nerve is seen as white cords some 2–3 mm thick.

The stylomastoid branch of the posterior auricular artery passes superfcial to the nerve to enter the stylomastoid foramen. Damage to this vessel should be avoided as bleeding may hamper vision, and also it supplies a nutrient branch to the nerve. The curved mosquito forceps are used for dissection by opening the blades a little at a time to stretch the tissues and raise it, so as to lift the gland substance off the surface of the nerve, and then expose it by cutting through the gland with scissors. At all times when a cut is made, the adjacent nerve must be seen clearly.

Almost immediately the nerve trunk starts to travel laterally within the parotid, and just below the neck of the condyle, it splits into an upper temporofacial and a lower cervicofacial division. Follow the lower division frst, and trace the cervical or the marginal mandibular branch anteriorly to a point in front of the parotid to mobilize the lower pole completely. Then by progressing upward, branch by branch further mobilization can be achieved (Fig. 46.31). Some tissue should always be left on the tumor to ensure complete removal.

In general, the nerves pass superfcial to the retromandibular vein, but some may pass deep to it. Careful mobilization of both nerve and vein with division and ligation of the latter is necessary. Tiny vessels should be sealed with bipolar diathermy avoiding damage to adjacent nerves.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.31** Parotidectomy with preservation of the facial nerve

#### **46.8.3.3 Functional Superfcial Parotidectomy**  [76]

This is superfcial parotidectomy where gland function is preserved by preservation of the Stenson's duct. If the duct is superfcial to the buccal branch, its preservation is contraindicated as it will obstruct the surgical procedure. After raising the skin fap and exposing the parotid gland, the duct is identifed passing on the masseter muscle. Stenson's duct is located; dissection and ligation of the duct are avoided unless it is located superfcial to the buccal branches of the facial nerve. Rest of the procedure is similar to superfcial parotidectomy.

#### **Advantages**


It decreases postoperative complications.

#### **46.8.3.4 Partial Superfcial Parotidectomy**

This is similar to local excision of parotid gland. Maximum healthy tissue is left behind without compromising on the clearance. The advantage of this procedure over superfcial parotidectomy is relatively low incidence of Frey's syndrome. The reported incidence of this complication is 4.8% [77]. In addition, better gland function is preserved due to more parenchyma that is left back [78].

#### **46.8.3.5 Intraoral Deep Lobe Tumor Excision** [79]

It is a transoral approach used in removal of few benign tumors of the deep lobe, which are easily visible displacing the superior portion of the tonsil and soft palate medially. An incision is made with cautery or knife over the most prominent aspect of the swelling in the tonsil and palate area, extending above and below the apparent location of the tumor. The constrictor muscle is identifed, and dissection is continued through thinned constrictor muscle by dividing it above and below the tumor. Pressure on the neck often assists in removal of the tumor. Fascial connections from the tumor into the adjacent bed are removed with blunt dissection, and the tumor is delivered into the mouth. Any vascular connections to the tumor should be cauterized, and meticulous hemostasis should be achieved. The superior and inferior portions of the wound are closed with interrupted sutures. The middle portion of the wound is left open to heal secondarily.

#### **Complications**


#### **46.8.3.6 Total Parotidectomy with or Without Facial Nerve Preservation**

It is usually indicated in tumors affecting the deep lobe. A neoplasm of the deep part of the parotid enters the soft palate through the interval between the styloid process and the back of the mandible and is often of dumbbell shape with the isthmus lying in this gap. After raising a skin fap, the facial nerve is identifed and dissected out leaving a layer of glandular tissue on it. An access osteotomy either in the form of vertical subsigmoid or mandibular body distal to the mental foramen is used to open up the interval between the mandible and the styloid process through which the tumor has passed. The stylohyoid muscle may be divided close to the styloid process and turned forward. The external carotid artery will be encountered emerging above the muscles and should be divided. The origin of the facial artery should be identifed to check the identity of the vessel.

As the parotid gland and the tumor are freed, it may be raised up between the two nerve bundles or below both bundles. Next entry is made intraorally over the tumor, and under direct vision tissues are divided to deliver the mass. Care is taken to avoid damaging the internal jugular vein and internal carotid artery which lie deep to styloid process. Following removal of the mass, the wound is irrigated, and the oral tissues closed with care using resorbable suture. The drapes are replaced over the mouth, gloves changed, and the mandibular fragments fxed together and the wound closed in the normal way.

#### **46.8.3.7 Parotidectomy Using SMAS Plane for Dissection** [73]

The advantages of this fap are that exposure of the gland is suffcient and the dissection is easy to perform. There is no donor-site morbidity, minimum additional operating time, and no extra cost. It seems to decrease the incidence of Frey's syndrome. The speed of the recovery of the facial nerve has been highlighted in the literature. It is more satisfactory from the patient's point of view.

#### **46.8.3.8 Parotidomandibulectomy and Temporoparotidectomy** [80]

Parotidomandibulectomy is indicated where there is invasion of the mandible by a malignant neoplasm.

In temporoparatidectomy, small-scale resection of the external auditory canal may be included with the excision of the pinna and overlying skin of the parotid where these structures are involved. The defciency may be made good with a deltopectoral or other suitable fap.

#### **46.8.4 Parotidectomy in Continuity with Neck Dissection**

In the case of lymph node metastasis as stated in surgical pathology, neck dissection can be done in continuity with parotidectomy by increasing the neck skin crease incision and clearing the lymphatic structures.

#### **46.8.5 Complications of Parotid Surgery**


#### **46.9 Surgical Management of Submandibular and Sublingual Gland Tumors**

Small tumors confned to the gland are treated by sialadenectomy, and tumors spreading beyond the confnes of the gland are treated with a wider en bloc excision, which may include resection of the foor of mouth and mandible depending on extent of tumor. The neurotropic tumors might involve the lingual, hypoglossal, mylohyoid, and marginal mandibular nerve leading to a perineurial spread which can be confrmed on frozen section. Thickening and nodularity of the nerves may indicate perineural involvement [81].

#### **46.9.1 Incision**

For submandibular sialadenectomy, a skin crease incision below 3 cm from the lower border of mandible is taken to avoid damaging the marginal mandibular nerve which loops below the lower border of the mandible (Fig. 46.32).

For simple excision of the sublingual gland, an incision is made in the foor of the mouth lateral to the submandibular

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.32** Submandibular incision

duct taking care to limit it up to premolar region, as at the molar region, there is a chance to damage the lingual nerve. When sublingual gland excision is necessary for a tumor, it should be removed with a wide margin including a rim resection of the mandible.

#### **46.9.2 Extracapsular Excision of the Submandibular Salivary Gland** [82]

After making an incision in the neck crease, skin fap is raised in the subplatysmal plane (Fig. 46.33). The capsule of the gland should be left intact when the sialadenectomy is being done for a tumor, which might compromise the marginal mandibular nerve. The facial artery and nerve are identifed as close to the gland as possible. After transection, they are elevated superiorly to identify and refect the marginal mandibular nerve. Nowadays the facial artery is spared during surgery to allow free fap anastomosis during oncosurgeries (Fig. 46.34). The investing fascia is then divided at the lower border of mandible, and the gland is delivered out from between the anterior and posterior bellies of the digastric muscle. Anteriorly the gland is separated from the mylohyoid muscle, and lingual nerve, hypoglossal nerve, and Wharton's duct are identifed. The lingual nerve shares the same facial sheath as the gland at the upper pole. This attachment of the lingual nerve to the gland represents its parasympathetic supply. The Wharton's duct is inferior to lingual nerve and is often surrounded by sublingual glands. As fascia and gland are mobilized upward from the surface of the hyoglossus, the hypoglossal nerve is identifed more inferiorly. It is accompanied by ranine vein. Posteriorly the angular tract

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.33** Submandibular gland exposure with subplatysmal dissection

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.34** Facial artery preservation in submandibular sialadenectomy

of fascia has to be cut with scissors to allow the gland in its fascial envelope to be drawn down without grasping the gland with instruments. Where necessary the upper pole may be mobilized via the mouth. An assistant can then depress the gland toward the submandibular wound to enable the operation to be concluded.

The duct and the branch of the lingual nerve supplying the submandibular gland are ligated and transected. The duct is divided close behind the papilla. During excision for infammatory disease, the nerve is always separated from the gland with knife or scissors. However, if the nerve appears to be involved in a tumor, it is sectioned in front of and behind the gland and the cut ends sutured. The wound is closed in layers with drainage in the usual way.

#### **46.10 Management of Minor Salivary Gland Tumors**

Surgical resection of minor salivary gland tumors depends on the site of origin and extent of disease. This may range from a wide local excision of localized low-grade tumors to more radical excision, including marginal or segmental mandibulectomy and/or partial or total resection of the hard or soft palate, partial or total maxillectomy, infratemporal fossa dissection, and/or anterior craniofacial resection for larger and/or high-grade tumors. The V2 and V3 divisions of the trigeminal nerve are at potential risk for perineural spread of minor salivary gland malignancy and may facilitate an early skull base metastasis. Resection of the cranial base may be required in some cases to eradicate the tumor and obtain negative surgical margins [81].

#### **46.10.1 Excision of Palatal Pleomorphic Adenomas** [83]

Small pleomorphic adenomas on the palate can cause pressure resorption of the bone but do not cause true bony invasion. They are managed by local excision along with the periosteum. In the case of involvement of greater palatine foramen area, the lesion is freed until it can be drawn down, and the vessels clamped and cauterized under direct vision. If not, the vessel retracts into the canal and causes irritating bleeding. The wound is left to granulate secondarily.

#### **46.10.2 Excision of Palatal Mucoepidermoid Carcinoma** [83]

Low-grade mucoepidermoid carcinomas may be treated by the excision of a full-thickness disk of palate, including palatal and alveolar bone. Nasal and oral mucous membranes are sutured together around the defect in the soft palate. Primary reconstruction is avoided and an obturator is used instead (Fig. 46.35a, b).

#### **46.10.3 Excision of Palatal Adenoid Cystic Carcinoma** [83]

Spread along the perineurial tissues makes an inadequate surgical margin very likely after surgical management of ACC. A combination of surgery and radiotherapy is best. Surgical excision should be generous. Hemimaxillectomy including the orbital foor is a minimum, unless there is very good evidence that less will be suffcient. Where the soft palate and pterygoid region are involved, extended maxillectomy approach is essential to ensure adequate excision under direct vision.

#### **46.10.4 Excision of Neoplasms of the Cheek and Lips**

A primary excision with a margin of normal adjacent tissue can be used, but if there is any doubt, it can be preceded by a biopsy. Re-operation following incomplete extirpation

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 46.35** (**a**) CT scan showing mucoepidermoid carcinoma of palate (red arrow). (**b**) Surgical excision of tumor using standard Weber-Ferguson incision

could mean the unnecessary sacrifce of tissue to ensure an adequate margin on the second occasion. Clinically aggressive neoplasms must be biopsied, since adequate treatment may involve radiotherapy and full-thickness excision and repair.

More aggressive tumors affecting the palatal salivary glands are managed by partial maxillectomy or total maxillectomy or extended maxillectomy based on the extent of disease.

#### **46.10.5 Complications**


Sensory abnormalities associated with greater auricular nerve sacrifce, refect as sensory defcit in the lower third of pinna including earlobe as well as adjacent preauricular and postauricular skin.

#### **46.11 Recent Advances** [84]

Robotic sialadenectomy of the submandibular gland has been done via a modifed face lift approach. Virgilio et al. performed robotic sialadenectomy of the submandibular gland in fve patients (two patients each with sialolithiasis and pleomorphic adenoma and one patient of ranula) with success. They used three robotic arms, two operative arms, and a facedown 30° endoscopic arm. The operative left arm is equipped with Maryland forceps and right arm with harmonic scalpel.

#### **46.12 Conclusion**

Salivary gland pathologies may be neoplastic, non-neoplastic, infammatory, or non-infammatory. Early surgical intervention after a good clinical, radiological, and histopathological diagnosis is need of an hour to minimize the postoperative complications. Early diagnosis and management with recent advanced technologies is the key factor in achieving excellent prognosis of the disease.

**Acknowledgment** Author wishes to thank Dr. Anshul Rai for Figs. 46.3, 46.4, 46.9, 46.13, 46.17a, b, and 46.20.

Author wishes to thank Dr. Kedar Saraf, Professor, Dept. of OMDR, SMBT Institute of Dental Sciences, Sangamner, Maharashtra, for Figs. 46.11a, b, and 46.12.

#### **References**


#### **Additional Reading**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Obstructive Salivary Gland Disease and Sialendoscopy**

**47**

Prithvi S. Bachalli and Aditya Moorthy

#### **47.1 Introduction**

Salivary gland diseases have been described in the literature for centuries. From the time of Hippocrates to the descriptions of parotid tumours in the sixteenth century and the anatomical descriptions of the ductal systems of the major salivary glands in the seventeenth century, we have assimilated knowledge of anatomy and pathology of these glands [1].

The conventional approach to infections of the salivary glands is medical management, occasional expression of the stone through the papilla, marsupialisation of the duct following removal of sialolith. Failing all, removal of the involved gland [2].

Minimally invasive surgery especially those in which endoscopes are utilized has gradually become popular over the last three decades. As a whole, the trend in surgery is to improve function and hasten recovery. To achieve these ends, a combination of technology and smaller incisions has been crucial. Hence there is an increasing interest to manage salivary gland diseases endoscopically [3].

Sialendoscopy is the endoscopic management of obstructive salivary ductal disease and has rapidly become the procedure of choice for such conditions.

#### **47.2 Obstructive Salivary Diseases**

Salivary gland diseases can broadly be classifed into ductal and parenchymal disorders.

P. S. Bachalli (\*) · A. Moorthy

Department of Oral and Maxillofacial Surgery, Rangadore Memorial Hospital, Apollo Hospitals, Bangalore, Karnataka, India

Some conditions, such as Sjögren's syndrome and juvenile recurrent parotitis, tend to have an overlapping component and thus are diffcult to segregate.

Ductal obstructions can be commonly attributed to-


The majority of obstructive salivary gland disease can be attributed to the presence of stones or sialoliths. Almost 60–70% of reported obstructive salivary disease comprises of sialolithiasis [4], which occurs in about 1.2% of the population. Amongst the major salivary glands, the submandibular is most affected (87%) , then the parotid (10%), and the sublingual (3%) to a much lesser extent [5].

Although sialolithiasis has been reported as the most common cause of salivary ductal obstructions, strictures, mucous plugs and the rare foreign body can cause signifcant obstruction to ductal fow.

#### **47.3 Sialendoscopy**

Sialendoscopy is a minimally invasive technique which makes use of miniature endoscopes to diagnose and treat salivary gland pathologies, including sialolithiasis, sialadenitis and strictures.

It is fast becoming the investigating procedure of choice for such conditions. Sialendoscopy has grown as a subspeciality in the last three decades, since the frst attempts to retrieve salivary stones endoscopically were carried out. It is slowly gaining popularity and awareness in the last decade and a half.

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_47) contains supplementary material, which is available to authorized users.

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 975

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_47

#### **47.4 Evolution of Sialendoscopy**

It took a few centuries, after the discovery of the ductal systems, for the frst endoscopy to be reported. In 1990, Konigsberger et al. reported the frst successful salivary endoscopy using a 0.8-mm fexible endoscope. Katz removed a stone with a fexible scope using blind passage of a basket in 1991, and for over a decade, both Nahlieli et al. and Marchal described various types of sialendoscopy instruments and approaches [3].

The last decade and a half has witnessed signifcant development of minimally invasive techniques for diagnosing and treating salivary ductal obstructions. Like with other surgical felds, this has led to a paradigm shift from open procedures to minimally invasive and endoscopic techniques with the emphasis on gland preservation and restoration of function. The miniaturization of endoscopes and advancing technology have made exploration and visualization of salivary ductal system possible using sialendoscopes [4].

#### **47.5 Indications and Contraindications**

As mentioned previously, sialolithiasis is the most common obstructive condition affecting the salivary duct and therefore is where sialendoscopic/sialendoscopy-assisted retrieval of sialoliths is most indicated.

Ductal strictures which may be secondary to calculi or those at the papilla opening can be very effectively treated by serial dilatation with sialendoscopes of increasing diameter [4].

Juvenile recurrent parotitis (JRP) is an infammatory condition affecting the parotid gland and is the second most common condition in children after mumps [6, 7]. The condition affects the paediatric population primarily especially the ages between 3 and 6 years and occasionally persists in adolescence [8]. As the cause is unknown, management has generally been conservative. Anatomical aberrations, such as kinks in the duct, dehydration and possible ascending bacterial infection, have been hypothesised as causes.

Dilatation and lavage as a consequence of performing sialendoscopy has provided relief from symptoms and reduction in the frequency of attacks, even though the mechanism is not fully understood. This condition has a tendency of spontaneous cessation at puberty.

Although in Sjogren's syndrome, where the parenchyma of the parotid gland is primarily affected, there is also an associated ductal pathology, namely, strictures. Here too dilatation via sialendoscopy can provide symptomatic relief.

Acute infammation of salivary glands and ducts is a contraindication to performing sialendoscopy. The duct is essentially a condensation of surrounding epithelium and not a rigid structure. In such an infamed state, the risk of creating a false passage or perforating the duct is signifcantly higher [4].

Management in such situations is conservative, mainly with the use of appropriate antibiotics and analgesics, incision and drainage of a collection, and removal of cause, such as a sialolith, if easily visible or accessible, to allow acute symptoms to settle before a formal sialendoscopy is carried out.

Trismus is a relative contraindication to performing sialendoscopy, as naturally, reduction in mouth opening makes it both diffcult to introduce and manoeuvre the scopes.

#### **47.6 Investigations**

A simple ultrasound in the hands of an experienced sonologist usually provides adequate information prior to sialendoscopy. It is a non-invasive, economical investigation which can determine the presence and size of sialoliths, strictures, dilatation or fbrosis of the duct. Alternatively a CT scan can be considered to achieve the same result.

MR sialograms are particularly useful in identifying strictures or areas of stenosis. However, like conventional sialography the papilla needs to be dilated and cannulated to inject the dye. In the hands of an inexperienced operator, damage to papilla might make performing sialendoscopy impossible.

#### **47.7 Armamentarium**

The sialendoscope can be divided very simply into two systems: the Marchal All-in-one (Fig. 47.1) and the Modular system (Fig. 47.2).

As the name suggests, the all-in-one has an irrigation port, a working channel through which various instruments can be introduced, and fbre optics in the same unit. This scope serves as both diagnostic and as an interventional tool.

The modular sialoendoscope consists only of a telescope, attached fbre-optic cable and an eyepiece. Interchangeable sheaths of various diameters are available which ft onto the basic telescope [6]. This scope with the appropriate sheaths can be used for both diagnostic and interventional purposes.

The sheaths used in the modular system make it rigid and unfortunately also bulky; thus signifcant dilatation of the papilla is required to introduce the scope [6].

Unlike other endoscopes, sialendoscopes come with only a zero-degree viewing angle. The all-in-one is semirigid, with a 5–15-degree angulation at the tip to facilitate manoeuvrability especially while exploring branches of the duct.

Diagnostic scopes come with only an irrigation port, whereas a working channel is also provided in therapeutic scopes to introduce instruments such as wire baskets and graspers for entrapping stones, balloons for stricture dilation

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 47.1** Marchal All-in-one sialendoscope

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 47.3** Armamentarium. (1) Conic dilators, (2) Lacrimal probes, (3) Sialendoscopes, (4) Guide wire, (5) Sheaths for Modular sialendoscope, (6) hollow dilators, (7) vascular forceps, (8) papillotomy scissors

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 47.2** Modular sialendoscope with sheaths

and a holmium laser fbre or a micro drill to fragment sialoliths [6].

Diameter of available scopes range from 0.9 to 1.6 mm, the smallest purely diagnostic and others having various sizes of the working channel to allow certain instruments only. This is a disadvantage of the all-in-one system in that the entire scope has to be changed if a larger instrument is required, whereas in the modular only the sheath can be changed [6].

Preliminary instruments, those that are used to dilate the papilla to facilitate the introduction of the scope, are also available. These include two types of dilators, papillotomy scissors, guide wires and hollow dilators [6] (Fig. 47.3).

#### **47.8 Anaesthesia and Technique**

Anaesthetic of choice depends on the clinical and radiologically fndings and the anticipated diffculty of the procedure. Local anaesthetic, with or without sedation, is usually adequate for a diagnostic procedure. In cases where sialolith retrieval is planned, either endoscopically or with a combined approach, general anaesthetic is usually preferable. Antisecretory agents like atropine and glycopyrrolate are avoided [6].

#### **47.8.1 Positioning**

Patient is placed supine with head fxed on a head rest and turned towards the surgeon. Shoulder extension is preferable. The monitor is placed opposite the surgeon. The assistant is next to the surgeon [6].

#### **47.8.2 Identifcation, Cannulation and Dilatation of Punctum**

The Wharton's duct punctum is comparatively more diffcult to locate given the position is quite variable. There may even be a 'hood' of tissue obscuring the opening. In such situations, local anaesthetic can be infltrated around the area which stiffens the opening, thereby aiding in location. Occasionally an incision might need to be placed on the foor of the mouth accompanied by minimal dissection to locate the duct. The Stensen's duct opening is far easier to identify. It is located on the buccal mucosa opposite upper second molar. Once the punctum is identifed, the opening is serially dilated with conical dilator and probes of various sizes [6].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 47.4** Normal duct with vascular markings

#### **47.8.3 Sialendoscopic Evaluation**

Once the punctum is adequately dilated, the appropriate sialendoscope is introduced into the duct. The duct is normally a collapsed structure, and irrigation fluid is required to keep the lumen open to visualise the duct and to advance the scope (Fig. 47.4). Normal saline is the preferred choice of irrigant solution and is diluted with local anaesthetic if the patient is awake for the procedure.

The irrigant also serves an additional purpose as this also performs lavage of the duct, thereby washing out debris and mucous plugs which might be accumulated [6].

The endoscope is slowly and gently passed from the punctum till branches are identifed and explored if possible. This point of division of the duct is known as the hilum and is considered the end point of sialendoscopy. Alternatively, the presence of pathology such as a sialolith or stricture may prevent complete exploration of the duct (Figs. 47.5 and 47.6). It is important to note that once the pathology has been treated, the entire duct must be explored so as to ensure there are no further causes of obstruction, including the withdrawal of the scope under vision [6].

As the scope is guided through the primary and secondary ducts, the colour and texture of the mucosa are noted which are an indicator of the presence of infammation. In relation to sialoliths, the size, shape and position need to be assessed as these will determine the method of retrieval [6].

Between the submandibular and the parotid duct, the Stensen's duct is comparatively more diffcult to navigate due to the presence of the masseteric bend.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 47.5** Sialolith

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 47.6** Stricture

#### **47.9 Diagnostic vs. Interventional Sialendoscopy**

Indications for a diagnostic procedure include clinical symptoms, yet an unremarkable ultrasound and stricture at the papilla opening, to assess size and position of sialoliths.

Diagnostic sialendoscopy is a low morbidity, minimally invasive technique, which becomes the investigational procedure of choice for salivary duct pathologies in all age groups. Sialendoscopy has the advantage of offering a realtime ductal view. Diagnostic endoscopy is occasionally therapeutic, in minor obstructions caused by mucous plugs which can be relieved by lavage.

Interventional sialendoscopy makes use of a wide array of armamentarium including wire baskets (Fig. 47.7), balloon catheters and holmium laser to assist in sialolith retrieval (Fig. 47.8).

Sialoliths with sizes ranging between 3 and 4 mm are amenable for endoscopic retrieval. Here they may be

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 47.7** Sialolith entrapped within wire basket

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 47.8** Laser lithotripsy

entrapped and retrieved by use of a wire basket or dragged to the punctual opening where a small incision is placed to facilitate removal.

Larger stones require a combined approach, whereby the position of the sialolith is identifed and marked endoscopically and retrieved with an open surgical approach. The open approaches for submandibular sialoliths may be as small as a papillotomy or an extensive dissection of the foor of the mouth. The lingual nerve and iatrogenic ranula formation are important considerations when operating in this region. Large parotid stones require a SMAS fap, for the identifcation and protection of facial nerve branches and the duct, as well as reconstruction post-retrieval. Sialocele formation is an important consideration.

Hollow bougies of increasing diameter can threaded over a guide wire to widen strictures at the papillae. Balloons are another means of treating ductal strictures and once introduced through the working channel of the sialendoscope are infated to dilate narrowed areas of the duct wall.

Stents are placed to maintain the patency of the duct and also to allow an incised duct to heal over with the aim of preventing stenosis. These stents are generally kept in place for up to 3 weeks. The authors have devised a salivary stent (Moorthy-Bachalli stent), made of polyurethane. These stents are available in sizes ranging from 3.5 French (diameter, 1 Fr = 0.3 mm) to 8 French and lengths from 5 to 7 cm with markings every centimetre. The stents also have a fange with prefabricated suture holes to facilitate suturing to the surrounding mucosa. An Ethilon 4-0 suture is preferred by the authors.

#### **47.10 Complications**

Like any other surgical procedure, open or endoscopic, sialendoscopy has its fair share of complications (Table 47.1).

#### **Table 47.1** Complications of sialendoscopy


#### **47.11 Summary**

When compared to other medical specialities, particularly otorhinolaryngologists, maxillofacial surgery is still in a primitive stage as far as the use of endovision is concerned. Hopefully an interest in areas like endoscopic management of salivary gland and temporomandibular joint diseases will narrow this gap.

Sialendoscopy is still in its infancy, in many parts of the world. Despite the challenges, growing awareness and the added attraction of minimally invasive surgery is steadily making it a popular choice for managing salivary ductal disease.

#### **References**

1. Marchal F. Sialendoscopy: the endoscopic approach to salivary gland ductal pathologies. Endo Press: Tuttlingen; 2012. pp 8.


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

**Part XVI**

**Maxillofacial Traumatology**

## **Primary Assessment and Care in Maxillofacial Trauma**

Saurabh Saigal and Manal M. Khan

#### **48.1 Introduction** [1, 2]

Maxillofacial injuries are common in polytrauma patients, and spectrum can be minor to life-threatening injuries. Primary assessment and management can be very important. They can involve facial soft tissues, facial bones, or both. Maxillofacial injuries can be due to various causes including road traffc accidents, assaults, and fall from height, industrial injuries, animal bites, sports injuries, burns, and war injuries. Lifethreatening maxillofacial injuries can complicate the initial management of a trauma patient due to presence of concomitant injuries to airway, head, or cervical spine.

The mechanism for this injury is exemplifed by an unbelted automobile passenger who is thrown into the windshield and dashboard. Trauma to midface can produce fractures and dislocations that compromise the nasopharynx and oropharynx. Facial fractures can be associated with hemorrhage, increased secretion, and dislodged teeth. Fractures of mandible, especially bilateral body fractures, can cause loss of normal airway and structural support. Airway obstruction can result if the patient is in supine position.

The term "golden hour" has to be kept in mind while handling the trauma patient which indicates that the injured patient has 1 h (60 min) from the time of injury to receive defnitive care. After that there will be signifcant increase in the morbidity and mortality of the patient. "Chances of survival of the critically injured patient will largerly determine after the frst hour" [3].

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_48) contains supplementary material, which is available to authorized users.

S. Saigal (\*)

Department of Anaesthesiology, AIIMS Bhopal, Bhopal, Madhya Pradesh, India e-mail: saurabh.criticalcare@aiimsbhopal.edu.in

#### M. M. Khan

Department of Burns and Plastic Surgery, AIIMS Bhopal, Bhopal, Madhya Pradesh, India

#### **48.2 Triage** [4]

Sorting of patients based on their need for treatment and the available resources to provide the treatment is triage. This sorting may be carried out by the paramedic team at the accident scene or receiving hospital who decides what level of care is required. It may be based on which patients need immediate, lifesaving interventions, which can wait and which are, in fact, beyond saving. Depending on the urgency of treatment required, maxillofacial injuries can be broadly placed into one of four groups (Table 48.1).

Appropriate triage and prompt evaluation, using the Advanced Trauma Life Support (ATLS) system, beneft patients [5].

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_48

**48**


#### **Table 48.1** Triage color coding

#### **48.2.1 Glasgow Coma Scale (Please Refer Table 7.5 in Chap. 7 of this book)**

There are three variables used with the scale:

Best motor response (level of central nervous system function) Best verbal response (ability of CNS to integrate information) Eye opening (brainstem activity)

#### **48.3 Primary Survey and Resuscitation** [6]

The primary survey is a rapid, reproducible physical examination to evaluate every trauma patient and is designed to diagnose and treat immediately life-threatening conditions frst. All patients are evaluated for physiologic or anatomic derangements that could lead to early mortality and morbidity. Treatment of problems identifed during the primary survey begins without delay, before the survey is completed.

The sequence of primary survey is ABCDE:


Patient monitoring (pulse oximetry, electrocardiogram (ECG), blood pressure (BP), blood results, chest and pelvic radiographs) should run in parallel with the primary survey. Team approach is crucial for primary survey.

#### **48.3.1 Airway with Cervical Spine Control**

Airway assessment is frst and foremost priority of primary survey. Patients with maxillofacial and head injuries are at high risk of compromised airway.

Causes of upper airway obstruction


Maxillofacial injuries can cause airway obstruction because of:


The chin lift or jaw-thrust maneuver is recommended to achieve patency of airway. The patient's head and neck should not be hyperextended, hyperflexed, or rotated to establish and maintain the airway. There may be associated cervical spine injury; all the cases are treated as they are having cervical spine injury unless diagnosed otherwise. Hence, cervical spine stabilization should be done.

#### **48.3.2 Airway and Ventilatory Problems in Maxillofacial Trauma (Please Refer Chap. 7 of this book)**

Early preventable deaths from airway problem after maxillofacial trauma often result from:


#### **48.3.3 Airway and Ventilation Are the First Priorities**

Airway compromise may be sudden and complete, insidious and partial, and/or progressive and recurrent. The early sign of airway or ventilator compromise is tachypnea or inability to speak words or sentences. "Talking patient" provides reassurance for that period of time that the airway is patent and not compromised. Failure to respond or an inappropriate response suggests an altered level of consciousness, airway and ventilator compromise, or both. Patient with the altered level of consciousness is at particular risk for airway compromise and aspiration, so he requires defnite airway.

#### **48.3.4 Objective Signs of Airway Obstruction**


#### **48.3.5 Airway Management** [7, 8]

To assess airway patency and adequate ventilation quickly and accurately, pulse oximetry and end-tidal CO2 measurement are essential. There are some measures to improve the oxygenation including airway maintenance techniques, defnitive airway measures, or surgical airways. Because abovementioned measures include some movement of the neck, it is important to maintain cervical spine protection in all patients of trauma.

High-fow oxygen is required both before and immediately after airway management measures are instituted. A rigid suction device is essential and should be readily available. Nasal route for endotracheal route should not be chosen in patients with facial injury and midface injury. Patients who are wearing helmet and require airway management need their head and neck held in a neutral position. For this two-person procedure, one person provides manual inline stabilization from below, while the second person expands the helmet laterally and removes it from above. Then inline stabilization is re-established from above. And patient's head and neck are secured during airway management. Removal of the helmet using a cast cutter while stabilizing the head and neck can minimize cervical spine (C spine) motion in

*Tracheostomy - Video 48.1*.

patients with known C spine injury [9].

#### **Box 48.2 Need for Airway Protection**

	- Neck hematoma
	- Laryngeal or trachea
	- Stridor
	- (i) Bleeding
	- (ii) Vomiting

#### **Box 48.3 Need for Ventilation or Oxygenation**

	- Tachypnea
	- Hypoxia
	- Hypercapnia
	- Cyanosis
	- Neuromuscular paralysis
	- Unconscious

#### **48.3.6 Breathing with Ventilation**

Next, the patient's breathing, ventilation, and oxygenation should be assessed, and any life-threatening derangements must be treated. Physical examination, pulse oximetry, and continuous end-tidal carbon dioxide monitoring should be used. For proper ventilation the lungs, chest wall, and diaphragm must all function adequately.

The most common interventions performed during the primary survey to support breathing are supplemental oxygen delivery, assisted or mechanical ventilation, and tube thoracotomy or chest tube insertion.

#### **48.3.7 Ventilation**

Sometimes it will happen that airway of the patient will be patent but ventilation will be inadequate, so look for the objective signs of inadequate ventilation**.** Ventilation may be compromised by airway obstruction, altered ventilatory mechanics, and central nervous system depression.

Following are the conditions where the ventilation may be compromised:


#### **48.3.8 Objective Signs of Inadequate Ventilation**


injury. Beware of rapid respiratory rate—tachypnea can indicate respiratory distress.

3. Use a pulse oximeter: This device provides information regarding patient's oxygen saturation and peripheral perfusion.

#### **48.3.9 Circulation and Hemorrhage Control**

Circulation must be assessed to determine the presence or absence of shock after addressing the highest priorities in the primary survey (airway and breathing). Shock is defned as inadequate organ perfusion and tissue oxygenation. In the trauma patient, shock is assumed to be hypovolemic/hemorrhagic, and resuscitation begins as soon as vascular access can be obtained. The possibility of neurogenic shock (e.g., spinal cord injury) or cardiogenic shock (e.g., pericardial tamponade) should also be considered. The focus of this segment of the primary survey should be assessing for the presence of shock, determining the cause (usually blood loss), and beginning resuscitation.

Signs of poor perfusion include a weak pulse, cool or clammy extremities, dry mucous membranes, pale skin, and confusion. A normal mental status examination confrms the presence of acceptable cerebral perfusion. The goal of resuscitation is to maintain tissue perfusion and homeostasis.

#### **48.3.10 Bleeding**

External or internal bleeding source should be identifed. External hemorrhage is identifed and controlled during the primary survey. Rapid external blood loss is managed:


Internal hemorrhage areas are chest, abdomen, retroperitoneum, pelvis, and long bones. Chest X-ray, pelvic X-ray, or focused assessment sonography in trauma (FAST) can be done to identify the source of bleeding.

#### **48.3.11 Disability Management**

The primary focus is on rapidly determining a patient's mental status and neurologic function via physical examination. The Glasgow Coma Scale (GCS) is a rapid and reliable way to quantify a patient's level of consciousness (Table 7.5). The GCS score allows for quick communication among clinicians about a patient's current mental status and can be important for decision-making. The neurologic assessment also includes an examination of the cranial nerves, pupils, and sensory and motor function.

#### **48.3.12 Exposure with Environment Control**

Exposure and environment are the fnal components of the primary survey. While lowering priority, they are still vital to the successful management of the trauma patient. The patients should be completely exposed so that injuries can be fully assessed. Decontamination may also be needed, depending on the nature of the trauma. Protection from hypothermia and continuous temperature monitoring are essential.

#### **48.3.13 Monitoring of Adequacy of Oxygenation**

Oxygenated inspired air is best provided via tight-ftting oxygen reservoir face mask with a fow rate of at least 11 L/ min. Other methods (e.g., nasal catheter and non-breather mask) can improve the inspired oxygen concentration. Pulse oximetry is a noninvasive method of continuously measuring the oxygen saturation (O2 sat) of arterial blood. It does not measure the partial pressure of oxygen (PaO2), and depending upon the position of oxy-hemoglobin dissociation curve, the PaO2 can vary widely. However a measured saturation of 95% or greater by pulse oximetry strongly suggests adequate peripheral artery oxygenation (PaO2 > 70 mmHg).

Pulse oximetry requires intact peripheral perfusion and can't distinguish oxy-hemoglobin from carboxy-hemoglobin or methemoglobin, which limits its usefulness in patients with severe vasoconstriction and those with carbon monoxide poisoning. Profound anemia (Hb > 5 g/dL) and hypothermia (<30 °C) decrease the reliability of the technique. However, in most patient pulse oximetry is useful as the continuous monitoring of oxygen saturation provides an immediate assessment of therapeutic intervention.

#### **48.3.14 Electrocardiographic (ECG) Monitoring**

ECG monitoring of trauma patient is important.


#### **48.3.15 Fluid Resuscitation**

Warm resuscitation fuids should be given. IV fuid therapy with crystalloids should be initiated. A bolus of 1–2 L of an isotonic solution may be required to achieve an appropriate response in adult patient.

#### **48.3.16 Urinary and Gastric Catheters**

Urine output monitoring is important to manage the fuid therapy. Urine output refects renal perfusion, and it is accomplished by insertion of indwelling bladder catheter.

Contraindications to the placement of Foley catheter and urethral injury should be suspected in the presence of:


A gastric tube is indicated to:


#### **48.4 Secondary Survey** [10–12]

Once the primary survey is completed, secondary survey is started. If additional personnel is available, then part of secondary survey can be conducted along with primary survey; however, it should be made sure that it does not interfere with primary survey, as primary survey is the frst priority.

Secondary survey is a complete head to toe examination of the trauma patient which includes complete history taking and physical examination. During secondary survey, a complete neurologic examination is conducted. Patient's GCS score is identified, radiographs are obtained, and laboratory studies are conducted as indicated.

#### **48.4.1 History Taking**

A complete medical assessment includes history taking and understanding the mechanism of the injury. Often, patient is not in a condition to provide this history. In such cases, it should be obtained from the family members. The history taking involves identification of various allergies, present medications, past history of any illness, pregnancy, last meal taken, and the event of trauma. The mechanism of injury must be understood whether it's inflicted by a penetrating or blunt trauma or if the injury is thermal injury or due to hazardous environment.

#### **48.4.2 Physical Examination**

During physical examination in secondary survey, a sequence has to be followed, which is examination of head, maxillofacial structures, cervical spine and neck, chest, abdomen, perineum/rectum/vagina, musculoskeletal system, and neurologic system.

#### **48.4.3 Four-Person Logroll**

To examine the patient's back and remove the spine board, at least four persons are required for logrolling:


#### **48.4.4 Head**

Secondary survey starts with examination of head which involves identifcation of injuries. The complete scalp should be examined for lacerations, contusions, and evidence of fractures. Other than these injuries, visual acuity, pupillary size, hemorrhage of conjunctiva and/or fundi, and ocular entrapment must be examined. These aspects must be re-evaluated once the periocular edema subsides.

Visual acuity examination must be done by asking the patient to read printed material such as handheld Snellen chart. To exclude ocular entrapment, ocular movement must be checked.

#### **48.4.4.1 Classifcation of Brain Injury**


Intracranial lesions may be classifed as diffuse or focal. The focal lesions include epidural hematomas, subdural hematomas, contusions, and intracerebral hematomas.

Signs of skull base fracture:


Computed tomography (CT) scan of the head should be carried out to accurately assess the neurologic injuries and detect mass lesions. CT scan helps in diagnosing:


In a comatose patient, motor responses may be elicited by pinching the trapezius muscle or with nail bed or supraorbital pressure. Testing for doll's eye movements (oculocephalic) the caloric test with ice water (oculovestibular) and testing of corneal responses are deferred to a neurosurgeon.

#### **48.4.5 Maxillofacial Structures**

Maxillofacial examination includes examination of soft tissue, palpation of all the bony structures, checking of occlusion, and intraoral examination. Trauma to the maxillofacial region not associated with airway obstruction should be treated once the patient is stabilized after the management of life-threatening injuries.

#### **48.4.6 Cervical Spine and Neck**

Patients with maxillofacial trauma must be presumed to have an unstable cervical spine injury unless it is proven otherwise. The absence of any neurologic defcit does not exclude the presence of any C spine injury. A complete cervical spine radiographs and CT scan should be done to evaluate C spine injury. The patient wearing any kind of helmet must be removed with extreme care.

C spine injuries can result from one or a combination of the following mechanism of injury:


A complete examination of neck includes inspection, palpation, and auscultation. Inspection should be done to note any blunt injury over the neck. Carotid arteries should be palpated and auscultated for bruits. Penetrating injuries of neck are potentially fatal. If the wound is deep, they should not be explored in emergency department [13].

A cervical collar can be applied to the patients suspecting the cervical spinal injury. Its role is to immobilize the C spine. Cervical collars are divided into two groups: soft and rigid collars. Soft collars are generally used for whiplash injury; some surgeons prefer rigid collars. Rigid collars provide excellent immobilization in transverse and sagittal planes compared with soft collars. However patient's comfort is to be taken into consideration in selecting the collars. The Philadelphia collar is available in two pieces having front and back pieces; it is held together by Velcro straps to support the neck [14].

#### **48.4.7 Chest**

Chest examination includes inspection, palpation, percussion, and auscultation. Inspection of anterior and posterior chest can identify conditions like open pneumothorax and large fail segments. Contusions and hematoma over chest suggest occult injury. Palpation of entire rib cage, clavicle, and sternum helps in diagnosing fractures. Signifcant injury may present with pain, dyspnea, and hypoxia.

Auscultation of high anterior chest helps in diagnosis of pneumothorax, whereas posterior base auscultation reveals hemothorax. Cardiac tamponade can be identifed by the presence of distant heart sounds and decreased pulse pressure. Presence of distended neck veins suggests cardiac tamponade and tension pneumothorax. A chest radiograph may confrm the presence of hemothorax or simple pneumothorax.

#### **48.4.7.1 Classifcation of Chest Trauma**

Immediate life-threatening chest injuries are to be identifed and treated during primary survey.

These six life-threatening chest injuries include:


#### **48.4.7.2 Managing Chest Trauma** [15]

The basic principles of management remain the same with the universal sequence of airway, breathing, and circulation to be treated in that sequence.

#### **48.4.7.3 Airway**

It is necessary to recognize and address major injuries affecting the airway during the primary survey. Airway patency and air exchange should be assessed by listening for air movement at the patient's nose, mouth, and lung felds; inspecting the oropharynx for foreign body obstruction; and observing for intercostal and supraclavicular muscle retractions. Laryngeal injury can accompany major thoracic trauma. Although the clinical presentation is occasionally delayed, acute airway obstruction from laryngeal trauma is a life-threatening injury. Injury to the upper chest can create a palpable defect in the region of the sternoclavicular joint, with posterior dislocation of the clavicular head, which causes upper airway obstruction. Identifcation of this injury is made by listening for upper airway obstruction (stridor) or a marked change in the expected voice quality, if the patient is able to talk. Management consists of a closed reduction of the injury, which can be performed by extending the shoulders or grasping the clavicle with a pointed instrument, such as a towel clamp, and manually reducing the fracture. Once reduced, this injury is usually stable if the patient remains in the supine position.

#### **48.4.7.4 Breathing**

The patient's chest and neck should be completely exposed to allow for assessment of breathing and the neck veins. This may require temporarily releasing the front of the cervical collar following blunt trauma. In this case, cervical spine immobilization should always be actively maintained by holding the patient's head while the collar is loose. Respiratory movement and quality of respirations are assessed by observing, palpating, and listening. Important, yet often subtle, signs of chest injury or hypoxia include an increased respiratory rate and change in the breathing pattern, which is often manifested by progressively shallower respirations. Cyanosis is a late sign of hypoxia in trauma patients. However, the absence of cyanosis does not necessarily indicate adequate tissue oxygenation or an adequate airway. The major thoracic injuries that affect breathing and that must be recognized and addressed during the primary survey include tension pneumothorax, open pneumothorax (sucking chest wound), fail chest and pulmonary contusion, and massive hemothorax.

*Important***:** After intubation, one of the common reasons for loss of breath sounds in the left thorax is a right mainstem intubation. During the reassessment, be sure to check the position of the endotracheal tube before assuming that the change in physical examination is due to a pneumothorax or hemothorax.

#### **48.4.7.5 Tension Pneumothorax**

A tension pneumothorax develops when a "one-way valve" air leak occurs from the lung or through the chest wall. Air is forced into the pleural space without any means of escape, eventually completely collapsing the affected lung. The mediastinum is displaced to the opposite side, decreasing venous return and compressing the opposite lung. Shock results from the marked decrease in venous return causing a reduction in cardiac output and is often classifed as obstructive shock (Fig. 48.1). The most common cause of tension pneumothorax is mechanical ventilation with positivepressure ventilation in patients with visceral pleural injury. However, a tension pneumothorax can complicate a simple pneumothorax following penetrating or blunt chest trauma in which a parenchymal lung injury fails to seal or after a mis-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 48.1** Tension pneumothorax

guided attempt at subclavian or internal jugular venous catheter insertion. Occasionally, traumatic defects in the chest wall also can cause a tension pneumothorax if incorrectly covered with occlusive dressings or if the defect itself constitutes a fap-valve mechanism. Tension pneumothorax rarely occurs from markedly displaced thoracic spine fractures. Tension pneumothorax is a clinical diagnosis refecting air under pressure in the affected pleural space. Treatment should not be delayed to wait for radiologic confrmation.

Tension pneumothorax is characterized by some or all of the following signs and symptoms:

Chest pain Air hunger Respiratory distress Tachycardia Hypotension Tracheal deviation away from the side of injury Unilateral absence of breath sounds Elevated hemithorax without respiratory movement Neck vein distention Cyanosis (late manifestation)

Because of the similarity in their signs, tension pneumothorax can be confused initially with cardiac tamponade. Differentiation is made by a hyper-resonant note on percussion, deviated trachea, and absent breath sounds over the affected hemithorax, which are signs of tension pneumothorax. Tension pneumothorax requires immediate decompression and may be managed initially by rapidly inserting a large-caliber needle into the second intercostal space in the midclavicular line of the affected hemithorax. However, due to variable thickness of the chest wall, kinking of the catheter, and other technical or anatomic complications, this maneuver may not be successful [16].

When successful, this maneuver converts the injury to a simple pneumothorax; however, the possibility of subsequent pneumothorax as a result of the needle stick now exists, so repeated reassessment of the patient is necessary. Chest wall thickness infuences the likelihood of success with needle decompression. Recent evidence suggests that a 5 cm needle will reach the pleural space >50% of the time, whereas an 8 cm needle will reach the pleural space >90% of the time. Even with a needle of the appropriate size, the maneuver will not always be successful. Defnitive treatment requires the insertion of a chest tube into the ffth intercostal space (usually at the nipple level), just anterior to the midaxillary line.

In a tension pneumothorax, air from a ruptured lung enters the pleural cavity without a means of escape. As air pressure builds up, the affected lung is compressed, and all of the mediastinal tissues are displaced to the opposite side of the chest.

#### **48.4.7.6 Open Pneumothorax (Sucking Chest Wound)**

Large defects of the chest wall that remain open can result in an open pneumothorax, which is also known as a sucking chest wound. Equilibration between intrathoracic pressure and atmospheric pressure is immediate. Air tends to follow the path of least resistance; as such, if the opening in the chest wall is approximately two-thirds of the diameter of the trachea or greater, air passes preferentially through the chest wall defect with each respiratory effort. Effective ventilation is thereby impaired, leading to hypoxia and hypercarbia. Initial management of an open pneumothorax is accomplished by promptly closing the defect with a sterile occlusive dressing. The dressing should be large enough to overlap the wound's edges and then taped securely on three sides in order to provide a futter-type valve effect. As the patient breathes in, the dressing occludes the wound, preventing air from entering. During exhalation, the open end of the dressing allows air to escape from the pleural space. A chest tube remote from the wound should be placed as soon as possible. Securely taping all edges of the dressing can cause air to accumulate in the thoracic cavity, resulting in a tension pneumothorax unless a chest tube is in place. Any occlusive dressing (e.g., plastic wrap or petrolatum gauze) may be used as a temporary measure so that rapid assessment can continue. Subsequent defnitive surgical closure of the defect is frequently required [17].

A fail chest occurs when a segment of the chest wall does not have bony continuity with the rest of the thoracic cage. This condition usually results from trauma associated with multiple rib fractures, that is, two or more adjacent ribs fractured in two or more places (Fig. 48.2). The presence of a fail chest segment results in disruption of normal chest wall movement. Although chest wall instability can lead to paradoxical motion of the chest wall during inspiration and expiration, this defect alone does not cause hypoxia. The major diffculty in fail chest stems from the injury to the underlying lung (pulmonary contusion). If the injury to the underlying lung is signifcant, serious hypoxia can result. Restricted chest wall movement associated with pain and underlying lung injury is major causes of hypoxia. Flail chest may not be apparent initially if a patient's chest wall has been splinted, in which case he or she will move air poorly and movement of the thorax will be asymmetrical and uncoordinated. Palpation of abnormal respiratory motion and crepitation of rib or cartilage fractures can aid the diagnosis. A satisfactory chest X-ray may suggest multiple rib fractures but may not show costochondral separation. Initial treatment of fail chest includes adequate ventilation, administration of humidifed oxygen, and fuid resuscitation. In the absence of systemic hypotension, the administration of crystalloid intravenous solutions should be carefully controlled to prevent volume overload, which can further compromise the patient's respiratory status.

The defnitive treatment is to ensure adequate oxygenation, administer fuids judiciously, and provide analgesia to improve ventilation. The latter can be achieved with intravenous narcotics or local anesthetic administration, which

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 48.2** Flail chest with pulmonary contusion

avoids the potential respiratory depression common with systemic narcotics. The options for administration of local anesthetics include intermittent intercostal nerve block(s) and intrapleural, extrapleural, or epidural anesthesia. When used properly, local anesthetic agents can provide excellent analgesia and prevent the need for intubation. However, prevention of hypoxia is of paramount importance for trauma patients, and a short period of intubation and ventilation may be necessary until diagnosis of the entire injury pattern is complete. A careful assessment of the respiratory rate, arterial oxygen tension, and work of breathing will indicate appropriate timing for intubation and ventilation [18].

#### **48.4.7.8 Massive Hemothorax**

Massive hemothorax results from the rapid accumulation of more than 1500 mL of blood or one-third or more of the patient's blood volume in the chest cavity (Fig. 48.3). It is most commonly caused by a penetrating wound that disrupts the systemic or hilar vessels. However, massive hemothorax can also result from blunt trauma. In patients with massive hemothorax, the neck veins may be fat as a result of severe hypovolemia, or they may be distended if there is an associated tension pneumothorax. Rarely will the mechanical effects of massive intrathoracic blood shift the mediastinum enough to cause distended neck veins. A massive hemothorax is suggested when shock is associated with the absence of breath sounds or dullness to percussion on one side of the chest. This blood loss is complicated by hypoxia. Massive hemothorax is initially managed by the simultaneous restoration of blood volume and decompression of the chest cavity.

©Association of Oral and Maxillofacial Surgeons of India

Large-caliber intravenous lines and a rapid crystalloid infusion are begun, and type-specifc blood is administered as soon as possible. Blood from the chest tube should be collected in a device suitable for autotransfusion. A single chest tube (36 or 40 French) is inserted, usually at the nipple level, just anterior to the midaxillary line, and rapid restoration of volume continues as decompression of the chest cavity is completed. When massive hemothorax is suspected, prepare for autotransfusion. If 1500 mL of fuid is immediately evacuated, early thoracotomy is almost always required. Patients who have an initial output of less than 1500 mL of fuid, but continue to bleed, may also require thoracotomy. This decision is not based solely on the rate of continuing blood loss (200 mL/h for 2–4 h) but also on the patient's physiologic status. The persistent need for blood transfusions is an indication for thoracotomy. During patient resuscitation, the volume of blood initially drained from the chest tube and the rate of continuing blood loss must be factored into the amount of intravenous fuid required for replacement. The color of the blood (indicating an arterial or venous source) is a poor indicator of the necessity for thoracotomy. Penetrating anterior chest wounds medial to the nipple line and posterior wounds medial to the scapula should alert the practitioner to the possible need for thoracotomy because of potential damage to the great vessels, hilar structures, and the heart, with the associated potential for cardiac tamponade. Thoracotomy is not indicated unless a surgeon, qualifed by training and experience, is present.

#### **48.4.7.9 Cardiac Tamponade**

Cardiac tamponade (Fig. 48.4) most commonly results from penetrating injuries. However, blunt injury also can cause the pericardium to fll with blood from the heart, great vessels, or pericardial vessel. The human pericardial sac is a fxed fbrous structure; a relatively small amount of blood can restrict cardiac activity and interfere with cardiac flling. Cardiac tamponade may develop slowly, allowing for a less urgent evaluation, or may occur rapidly, requiring rapid diagnosis and treatment. The diagnosis of cardiac tamponade can be diffcult in the setting of a busy trauma or emergency room. Cardiac tamponade is indicated by the presence of the classic diagnostic Beck's triad: venous pressure elevation (distended neck veins), decline in arterial blood pressure, and muffed heart sounds. However, muffed heart tones are diffcult to assess in the noisy examination area, and distended neck veins may be absent due to hypovolemia. Additionally, tension pneumothorax, particularly on the left side, can mimic cardiac tamponade. Kussmaul's sign (a rise in venous pressure with inspiration when breathing spontaneously) is a true paradoxical venous pressure abnormality associated with tamponade. Pulseless electrical activity (PEA) is suggestive of cardiac tamponade but can have other causes, as listed above [19]. Insertion of a central venous line with measurement of central venous pressure (CVP) may aid diagnosis, but CVP can be elevated for a

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 48.4** Cardiac tamponade

variety of reasons. Additional diagnostic methods include echocardiogram, focused assessment sonography in trauma (FAST), or pericardial window. In hemodynamically abnormal patients with blunt or penetrating trauma and suspected cardiac tamponade, an examination of the pericardial sac for the presence of fuid should be obtained as part of a focused ultrasound examination performed by a properly trained provider in the emergency department (ED). FAST is a rapid and accurate method of imaging the heart and pericardium. It is 90–95% accurate for the presence of pericardial fuid for the experienced operator. Concomitant hemothorax may account for both false-positive and false-negative ultrasound exams. Prompt diagnosis and evacuation of pericardial blood are indicated for patients who do not respond to the usual measures of resuscitation for hemorrhagic shock and in whom cardiac tamponade is suspected. The diagnosis can usually be made with the FAST exam. If a qualifed surgeon is present, surgery should be performed to relieve the tamponade. This is best performed in the operating room if the patient's condition allows. If surgical intervention is not possible, pericardiocentesis can be diagnostic as well as therapeutic, but it is not a defnitive treatment for cardiac tamponade. However all patients with acute tamponade and a positive pericardiocentesis will require surgery to examine the heart and repair the injury. Pericardiocentesis may not be diagnostic or therapeutic when the blood in the pericardial sac has clotted. Preparation to transfer such a patient to an appropriate facility for defnitive care is always necessary. Pericardiotomy via thoracotomy is indicated only when a qualifed surgeon is available.

#### **48.4.8 Abdomen** [20]

Abdominal injuries must be identifed and managed aggressively. It is not as important to arrive at a specifc diagnosis as it is to recognize the injury which requires a surgical intervention. It is important to closely observe and re-evaluate the abdomen to identify the blunt injury. The safest management of penetrating wounds is a laparotomy.


The diagnostic peritoneal lavage (DPL) was used to diagnose blunt and occasionally penetrating abdominal trauma, but its use was decreased with the advancement of CT and USG. Focused assessment sonography in trauma (FAST) is very helpful to detect the presence of hemoperitoneum.

#### **48.4.8.1 Focused Assessment Sonography in Trauma (FAST)** [22]

The ultrasound machine and water-based gel are necessary to perform FAST.

Fast includes the following views:


#### **48.4.9 Perineum/Rectum/Vagina**

Contusions, hematomas, lacerations, and urethral bleedings should be examined in the perineal area. The presence of blood at urethral meatus suggests urethral injury. Inspect the scrotum and perineum for ecchymosis or hematoma, also suggestive of injury to the urethra. In patients with perineal hematoma or high-riding prostate, Foley catheters should be avoided.

Rectal examination can be done to evaluate the presence of blood within the bowel lumen. In patients with the risk of vaginal injury, vaginal examination should be carried out. Pelvic compressions should be carried out to identify any pelvic fractures. Pelvic fractures can be suspected by the presence of ecchymosis over iliac wings, pubis, scrotum, or labia. The pelvic fracture can be divided into closed, open book, and vertical shear fracture. Hemorrhage control and fuid resuscitation will be in the initial management of major pelvic disruption associated with hemorrhage. Pelvic binder or sheet can apply suffcient stability for the unstable pelvis at the level of greater trochanters of the femur bone.

#### **48.4.10 Musculoskeletal System**

The patient must be completely undressed for adequate examination. Extremities should be inspected for deformities, abrasion, and contusions. Presence of tenderness on palpation of bones and abnormal movement helps in identifcation of occult fractures. Signifcant injuries of extremities can exist without fracture being evident. Ligament ruptures and a muscle tendon unit injury interferes with active motions. The musculoskeletal examination is incomplete without examination of the back of the patient.

Musculoskeletal injuries are a potential source of blood loss in patients with hemodynamic abnormalities. The proper splint application helps in blood loss control, reducing pain, and preventing further soft tissue injury. Splinting is required in the patients with joint dislocations.

*Crush syndrome*: it refers to the injured muscle which if left untreated can lead to acute renal failure. Traumatic rhabdomyolysis ranges from asymptomatic illness with elevation of creatine kinase level to a life-threatening condition associated with acute renal failure and disseminated intravascular coagulation (DIC). Early and aggressive fuid therapy protects the kidneys and prevents renal failure in patients with rhabdomyolysis.

*Compartment syndrome*: develops when the pressure within an osteofascial compartment of muscle causes ischemia and subsequent necrosis. Sometimes fasciotomy is required to manage the condition.

#### **48.5 Conclusion**

Management of airway is challenging in patients with maxillofacial trauma. Securing airway in these patients is dependent on the clinical status and the features of trauma. Before initiation of airway management, a series of steps are to be planned. For optimal care, one must have adequate knowledge of the specifc attributes of diffcult airway. Also, the expertise in techniques for managing the diffcult airway, familiarity with devices, and recognition of failed airway are necessary. A multidisciplinary approach involving anesthesiologist, maxillofacial surgeon, and a trauma expert must be a practice for better outcome (please refer Chap. 7 for further reading).

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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## **Management of Soft Tissue Injuries in the Maxillofacial Region**

**49**

Abhay Datarkar and Shikha Tayal

#### **49.1 Introduction**

Soft tissue injuries are one of the most commonly encountered injuries in head and neck region and present especially in the emergency department or surgical casualty. They can be isolated soft tissue injuries, or injuries having concomitant skeletal trauma. The frequent facial soft tissue injuries include simple lacerations, abrasions, contusions, bites, avulsions, and burns. These injuries are complicated by presence of vital anatomical structures like vessels, ducts, nerves, and muscles. Presence of foreign debris and hematoma further complicates the soft tissue injuries. The face is a region of high esthetics and functional importance. Hence, there are many factors that help to manage such injuries.

Factors that guide facial soft tissue injury management are:


Disclosure: Authors have no fnancial conficts to disclose.

primarily closed as soon as they are seen and as long as active infection is not present.

To achieve this, the surgeon needs to understand the etiopathogenesis, surgical anatomy, biomechanics of tissue wound, biology of wound healing, and the art of soft tissue repair.

#### **49.2 Etiology**

The most common etiology of facial soft tissue injuries varies according to the age, sex, and geographical distribution of the population. Facial soft tissue trauma tends to occur in certain areas of the head depending on the causative mechanism. It typically includes the T-shaped area that includes forehead, nose, lips, and chin, followed by the occiput and anterior temporal areas.


A. Datarkar (\*) · S. Tayal

Department of Oral and Maxillofacial Surgery, Government Dental College and Hospital, Medical College Premises, Nagpur, Maharashtra, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 997

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_49


### **49.3 Classifcation of Soft Tissue Injuries**

Soft tissue injuries can be classifed into multiple categories:

#### (A) **Based on mechanism of injuries**

	- When injury is caused due to blunt force:
	- 1. Incised wounds
	- 2. Chop wounds
	- 3. Stab/punctured wounds
	- Due to excessive cold: e.g., frostbite

#### (B) **Legal classifcation**


**Box 49.1 Classifcation of Soft Tissue Injuries**

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 49.1** (**a**) Showing open wound where fractured left clavicle is visible from the wound surface. (**b**) Open wound of maxillofacial region where underlying mandible is visible

#### (C) **Based on the communication of the injury with the external environment**

**Closed wound**: Only the underlying tissue and/or structures are damaged without breaking the skin. Examples of closed wounds include hematomas, contusions, and crush injuries. These types of wounds are not contaminated and, hence, heal on their own without any sequelae.

**Open wounds**: There is a break in the skin, which exposes the underlying structures to the external environment. Open wounds include simple and complex lacerations, avulsions, punctures, abrasions, accidental tattooing, and retained foreign body with a tendency to heal with scarring. These injuries require extensive exploration and debridement followed by a course of antibiotic regimen for uneventful healing (Fig. 49.1).

(D) **According to the facial subunit(s) involved**. The major esthetic subunits on the face are the scalp, forehead, nose, periorbital region, cheek, perioral region, auricle, and neck [4].

> These major facial esthetic subunits are further divided into smaller subunits by location. The individual subunits must be reconstructed individually one by one in order to attain good esthetics (Fig. 49.2).

	- (a) **Injuries to nerve**—The nerve injuries are most commonly encountered in cases of open wounds.

The nerve injuries are further classifed into neuropraxia, axonotmesis, and neurotmesis (Seddon's classifcation of nerve injuries [5]). Sunderland [6] further revised this classifcation of nerve injuries based on the histologic degree of nerve damage. There should be careful evaluation of sensory and motor components of the nerves in the involved region for proper treatment. The most commonly encountered nerve injuries in maxillofacial region are the facial nerve and trigeminal nerve.


#### (F) **Rank and Wakefeld classifcation** [7] **of wounds**

(a) **Tidy wounds**—The wounds that are inficted by sharp instruments like surgical blades and contain

A. Datarkar and S. Tayal

©Association of Oral and Maxillofacial Surgeons of India

no devitalized tissue are called tidy. These wounds are closed primarily. Examples are surgical incisions, cuts from glass, and knife wounds.

(b) **Untidy wounds**—Untidy wounds result from crushing, tearing, avulsion, vascular injury, or burns and contain devitalized tissue. Such wounds must be managed by wound excision. The devitalized tissue is excised, and the untidy wound is converted into the tidy wound before proper closure is achieved. The chances of infection are high if inadequately managed.

#### (G) **CDC classifcation of surgical wounds**

A **surgical wound** is a wound created by incisions and placement of drains during surgeries.

Surgical wounds can be classifed into four different categories depending on the bacterial load, the risk of infection, and where the wound is located on the body.

**Class I**: **Clean wounds**. They show no signs of infection or infammation. They often involve the eye, skin, or vascular system. It is often due to nonpenetrating (blunt) trauma.

**Class II**: **Clean-contaminated wounds**. Although the wound may not show signs of infection, it is at an increased risk of becoming infected because of its location. For example, surgical wounds in the respiratory tract like oropharynx and gastrointestinal tract may be at a high risk of becoming infected.

**Class III**: **Contaminated wound**. A surgical wound in which an outside object has come into contact with the skin and has a high risk of infection. For example, a gunshot wound may contaminate the skin around where the surgical repair occurs.

**Class IV**: **Dirty-contaminated or infected wounds**.

The wounds that have been exposed to fecal material and have a high bacterial load.

This wound classifcation guides in choosing appropriate treatment as well as helps in predicting post-repair form and function.

#### **49.3.1 Common Soft Tissue Injuries**

The common clinical presentation of soft tissue injuries included abrasions, contusions, and lacerations.

1. **Abrasions**—(also known as gravel rash) (Fig. 49.3)—It is destruction of the superfcial layer of skin only. It is caused by frictional forces that are light enough to erode only the superfcial layer of epidermis. It can be scratches

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 49.3** Showing multiple abrasions over face involving the supraorbital region, nose, upper lip, and chin

or linear type of abrasion, graze or sliding abrasion, pressure abrasions, and impact abrasions.

The healing of abrasions takes place from the periphery of the wound towards the center by new growth of epithelial cells. The wound is bright red in color for the frst 12–24 h due to extravasation of blood which dries up to form a red scab. After 2–3 days, a reddish-brown scab is formed. After 4–7 days, epithelium grows and covers the defect under the scab, which gives it a dark brown to brownish-black appearance. After 7 days, the scab dries and ultimately falls off, leaving depigmented bright pinkish area underneath, which attains its normal pigmentation gradually over a period.

2. **Contusions (bruising)** (Figs. 49.4 and 49.5)—This is effusion of blood into the tissues, due to the rupture of small blood vessels at the site of impact. There is no destruction of the superfcial layer of skin. The subtypes are (a) intradermal, (b) subcutaneous, and (c) deep.

A bruise heals by disintegration of extravasated blood. The red cells in the wound are hemolyzed, and the hemoglobin molecule is broken down into hemosiderin, hematoidin, and bilirubin by the action of enzymes.

This type of injury demonstrates a change in the color of the wound according to the time lapsed after injury: red at the time of injury, blue within few hours to 3 days, and

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 49.4** Showing contusion wound over right cheek and periorbital ecchymosis of the right eye. The color changes can be appreciated intraorally

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 49.5** Showing bilateral periorbital ecchymosis (raccoon eyes)

bluish-black to brown color due to deposition of hemosiderin from the extravasated RBCs, by the 4th day. In 5–6 days, the wound appears greenish due to disintegration of hemoglobin to hemosiderin. Between 7 and 12 days, the wound appears yellow due to the presence of bilirubin which is the fnal disintegrated product from hemoglobin. The wound appears normal by 2 weeks. The various factors affecting the color of contusion include the depth of the bleeding, amount of extravasated blood, and overlying skin color.

3. **Lacerations**—It is the tear or split of skin, mucous membrane, muscle, or internal organs produced by the application of blunt force to a broad surface area, which

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 49.6** Showing split lacerated wound over the nose, columella, lower lip, and chin

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 49.7** Cut laceration having sharp clean cut edges

crushed or stretched tissues beyond the limits of their elasticity. They can be split lacerations (Fig. 49.6), stretch lacerations, shearing lacerations, and cut lacerations (Fig. 49.7).


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 49.8** Showing incised wound extending from dorsum of the nose till pre-auricular region; caused by knife in a case of assault

object, such as knife, sword, chisel, scissors, nail, needle, spear, arrow, screw driver, etc. into the depths of the body. This type of wound is deeper than its length and width. These can be of the following types:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 49.9** Showing penetrating wound. (**a**) Only the entry site is seen over the right temporal region. (**b**) The object remains dislodged within the body cavities

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 49.10** Showing gunshot wound injuries. (**a**) Picture showing entry wound over pre-auricular region. (**b**) Showing exit wound over right infraorbital region on opposite side

9. **Burn injuries**—Burns are injuries to tissues caused by heat, friction, electricity, radiation, or chemicals. Most burns are from hot objects (including fuids) and fre. Burns cause severe skin damage where the cells die. Burns are highly painful injuries which require specifc treatment as distinct from other injuries depending on the degree of burn.

The clinical presentation of burns depends largely on the depth of injury. Superfcial burns (frst degree) are confned to the epidermis. They are characterized by severe pain, dryness, and redness of skin. Superfcial partialthickness (second degree) burns extend into the papillary dermis. The skin is moist and red and blanches with pressure. Blisters are common in this type of injury. Deep partial-thickness burns extend into the reticular dermis. The skin is dry and appears yellow or white with minimal blistering. Full-thickness burns extending to the entire depth of dermis are classifed as 3rd degree. These are very severe injuries. The skin is stiff, leathery, and brown, but pain is not a common feature. Fourth-degree burns involve charring of skin and affect the deeper structures like fat and muscle. The skin is dry, black, and painless.

#### **49.4 Initial Evaluation and Assessment**

All trauma patients should be assessed and managed initially according to the principles of Advanced Trauma Life Support. Soft tissue injuries of the head and neck region can be accompanied by signifcant swelling and bleeding leading to airway compromise. The patient also should be assessed for associated ophthalmologic, intracranial, and cervical spine injuries.

#### **49.5 History and Examination**

Once the patient has been evaluated for life-threatening injuries and stabilized as necessary, a thorough and focused history and physical examination of the head and neck should be performed. History includes timing and mechanism of injury.

Early treatment of soft tissue injuries is associated with optimal esthetic outcomes. Determining the mechanism of injury may help the surgeon in managing the wounds with special consideration. For example, crush injuries may result in a larger area of compromised tissue than appreciated on initial examination. Tissue that appears healthy initially may subsequently necrose and may require serial debridement.

The site(s), depth, and nature of all wounds should be noted. Presence of nonviable tissue, gross contamination, and any foreign body like dirt and debris are important to discern.

Palpation helps to identify the presence of underlying bony injuries. Palpation can be done through the open wound itself.

#### **49.6 Management of Soft Tissue Injuries**

The principles of management of soft tissue injuries include the control of bleeding, copious irrigation of the wound, debridement of devitalized tissue, and removal of foreign bodies before closure.


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 49.11** Showing wound excision and serial debridement of an extensive untidy wound gradually healing secondarily

excised using sharp scissors, and the wound margins are freshened up. The toilet of any wound should be done in a systematic layer-wise manner from superfcial to deep (Fig. 49.11).

(f) **Closure**—Ideally, facial soft tissue injuries should be closed as early as possible. Primary closure of a wound should be completed within 8 h of injury when possible [9]. Early intervention and closure decreases the risk of infection as well as optimizes the functional and cosmetic result. Basic principles of suturing should be met, which include precise approximation and eversion of the skin edges, avoidance of excessive tension, and layerwise closure to prevent dead space and fuid accumulation.

If gaping of the lacerated margins or tissue loss is present that cannot be closed primarily, the tissue can be managed by regular dressing and allowed to heal secondarily. Revision surgeries to improve esthetics and function are performed after minimum of 9 months.

(g) **Reconstruction** [10]—Done in cases of extensive degloving injuries. There are several options for soft tissue reconstruction using faps. Starting from local, regional, distant faps and free microvascular faps, depending on the type, location, and extent of the injury (Box 49.2).

#### **49.7 Wound Dressings**

Wound dressings are sterile pads used to cover the wounds. Lister [11] introduced antiseptic dressings by soaking gauze in carbolic acid. The dressings should be clean and provide a warm and moist environment for the successful wound healing. The dressings should be frequently changed in order to keep the wound free from bacterial load. Antibacterial ointments must be applied over the wound to keep it lubricated and free from bacteria. The dressings are selected on the basis of two concepts: occlusion and absorption. The reasons for placing a wound dressing are enumerated in Box 49.3.

#### **Box 49.3 Purposes of Dressings**

*Purposes of applying dressings over wounds*


*In selected cases, the dressing is modifed to achieve additional purposes such as*


Studies [12] have demonstrated that the rate of epithelialization under a moist occlusive dressing is twice that of a wound that is left uncovered and allowed to dry. An occlusive dressing provides a mildly acidic pH and low oxygen tension on the wound surface, which is conducive for fbroblast proliferation and formation of granulation tissue.

However, wounds that produce signifcant amounts of exudate or have high bacterial counts require a dressing that is absorptive and prevents maceration of the surrounding skin. These dressings also need to reduce the bacterial load while absorbing the exudate produced. Placement of a pure occlusive dressing without bactericidal properties would allow bacterial overgrowth and worsen the infection.

The various types of dressings [13] can be enumerated as in Table 49.1.

#### **49.8 Other Therapies**

1. **Hyperbaric oxygen therapy**—uses oxygen as a drug and the hyperbaric chamber as a delivery system to increase PO2 at the target area. It involves inhalation of 100% oxygen at 1.9–2.5 atm, for sessions of 90–120 min each. Treatments are given once daily, fve to six times per week and should be given as an adjunct to surgical or medical therapies. Clinical evidence of wound improvement should be noted after 15–20 treatments.

**Table 49.1** Types of wound dressing materials


**Mechanism of action**—HBO therapy can increase tissue PO2 ten times higher than usual. The higher PaO2 is suffcient to supply the tissue with all its metabolic requirements even in the absence of hemoglobin. This elevated level lasts for 2–4 h after termination of HBO therapy and induces synthesis of endothelial cell NO synthase as well as angiogenesis. Oxygen stimulates angiogenesis, enhances fbroblast and leukocyte function, and normalizes cutaneous microvascular refexes, thus aiding in healing of chronic, complicated, non-healing wounds.

2. **Negative pressure-assisted wound therapy**—Argenta [14] and associates originally described the use of negative pressure to assist in wound closure in 1997. By applying subatmospheric pressure to wounds, they demonstrated removal of chronic edema, an increase in local blood fow, and stimulation of granulation tissue. This technique may be used on acute, subacute, and chronic wounds. The wound is flled with a foam substance. A drainage tube is inserted into, or laid on, the foam, and the part is then covered with impermeable flm. Suction is applied at around 125 mmHg between changes of dressing.

#### **49.9 Necrotizing Fasciitis**

It is a rapidly spreading necrotizing soft tissue infection, also known as fesh-eating disease. It is one of the most challenging infections faced by the maxillofacial surgeons due to its diagnosis and management. The most common bacteria responsible for the fascial necrosis are hemolytic *Streptococcus* and *Staphylococcus*.

It is foul-smelling with loss of skin and superfcial subcutaneous tissue, having patchy blackish necrosis and frank pus along with the raw surface of the wound, margins of which are pale and spreading in nature. If it involves the skin of scrotum, it is known as Fournier's gangrene.

The prompt diagnosis and aggressive treatment is the key to manage this complicated condition. Removal of the offending factors like carious tooth and infected foreign material is the prime step followed by aggressive debridement and desloughing involving the normal tissue margins under the antibiotic coverage and adequate anesthesia. Once the wound is free of the active infection, showing healing margins with no evidence of pus, it is reconstructed with the skin grafts (Fig. 49.12).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 49.12** Depicting a case of necrotizing fasciitis of the right side of the neck due to infection from right mandibular third molar. The patient was promptly and aggressively managed by sequential debridement followed by anterolateral thigh skin graft

#### **Table 49.2** Phases of wound healing


#### **49.10 Principles of Soft Tissue Healing**

The three phases of repair in soft tissue wounds are overlapping and include


Any alteration in the local environment of the wounds or the systemic status of the patients can infuence the normal process of wound healing.

#### **49.11 Types of Wound Healing**

The various types of wound healing include:


#### **Table 49.3** Factors that negatively infuence wound healing


3. **Secondary intention**—healing is by natural biologic processes without surgical intervention, and it usually occurs in large wounds associated with soft tissue loss or avulsion. It involves epithelialization and collagen deposition for wound healing. Contraction is the most important phenomenon in the spontaneous closure of large open wounds.

#### **49.12 Complications in Wound Healing**

Complications in the normal process of wound healing may occur due to presence of various local and systemic factors which exert a negative impact (Table 49.3).

One of the frequently observed complications is "abnormal wound healing" which presents in different forms such as keloids and hypertrophic scars. These are proliferative scars characterized by excessive net collagen deposition. Keloids and hypertrophic scars (Fig. 49.13) differ histologically from normal scars. The clinical appearance of the two types of scar is described in Table 49.4.

Keloids and hypertrophic scars contain collagen bundles aligned in the same plane as the epidermis. Tension

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 49.13** Showing. (**a**) keloid type of scar and (**b**) hypertrophic scar healing



over the edges of the wound signals the formation of activated fbroblasts resulting in excessive collagen deposition.

Scars perpendicular to the underlying muscle fibers tend to be flatter and narrower, with less collagen formation than when they are parallel to the underlying muscle fibers. As muscle fibers contract, the wound edges become reapproximated when they are perpendicular to the underlying muscle and tend to gape if placed parallel to it, leading to greater wound tension and scar formation.

#### **49.12.1 Prevention of Hypertrophic or Keloid Scars**

The four strategies that reduce adverse scarring immediately after wound closure are:


Postsurgical taping of the wound for 3 months can reduce scarring. Moisturizing lotions and moisture-retentive dressings (silicone sheets and gels) can reduce the thickness, discomfort, and itching and improve the appearance of the scar.

#### **49.13 Recent Advances in Soft Tissue Management**


They include—*Bioengineered Skin substitutes vis* [15]


(c) *Bilayer substitutes*—Integra, developed in 1981, was the frst acellular bilayer and has been used successfully to treat burns and chronic wound patients.

#### **49.14 Conclusion**

Proper assessment and classifcation of soft tissue injuries is the primary step in management. Early intervention and closure of soft tissue injuries is associated with optimal functional and esthetic outcomes as well as decreases the risk of complications. The basic principles of management of soft tissue injuries include the control of bleeding, copious irrigation of the wound, debridement of devitalized tissue, and removal of foreign bodies before closure. Administration of antibiotics and tetanus prophylaxis play a vital role in management of contaminated wounds. Wound dressings are mandatory to protect wounds postoperatively and facilitate ideal healing. Soft tissue injuries resulting in loss of tissue must be reconstructed using faps which may be local, regional, distant, or free microvascular faps, depending on the type, location, and extent of the injury. Innovative options such as growth factors, stem cell therapy, and bioengineered skin substitutes may be considered.

#### **49.15 Case Scenarios**

#### **Case Scenario 1**

A 23-year-old male patient met with a road traffc accident and suffered from a perforating injury over the nose, extending to right infra-orbital region. After initial resuscitating of the patient and ruling out the head injury component, the patient was taken up for the management of soft tissue and hard tissue injuries under general anesthesia. Through the existing lacerated wound, open reduction and internal fxation was done within 48 h of the trauma. Simultaneously, the soft tissue closure was performed layer-wise. Closure of the muscle layer was performed followed by the subcutaneous tissue and fnally the skin (Fig. 49.14a–e).

#### **Case Scenario 2**

A case scenario of a 67-year-old male patient who reported to the department of Oral and Maxillofacial Surgery. He was a victim of ballistic injury while he was working in a marketplace. The penetrating pathway of the bullet could be traced

**Fig. 49.14** Case scenario 1(a–e): Soft tissue management of a road traffc accident victim

having an entry site over left cheek. An extensive and careful exploration was performed in the OT under general anesthesia after the sections of 3D CT face were obtained (Fig. 49.15a–g). The comminuted fracture of the mandible was reconstructed using reconstruction plate. The bullet was found to be lodged in the carotid triangle just above the bifurcation of the common carotid artery.

Soft tissue management in such type of ballistic injuries becomes very critical. Since the bullet is a foreign material, it has to be removed from the soft tissues. The approach could either be through the entry wound but due to deep seating of the bullet into the neck and proximity of vital structures, one should always think of an extensive approach. The neck dissection was carried out in this case to remove the bullet from the bifurcation of common carotid artery in as atraumatic manner as possible. Bidigital palpation is a crucial step to locate the foreign body in this region. One interesting fact about such injuries is that though they are extensive with crushed and comminuted fractures and they are sterile due to the heat generated by the velocity of the bullet along its path. Such injuries are less prone to infection.

**Fig. 49.15** (a–g) Case Scenario 2: Soft tissue management in a ballistic injury

Proper surgical toilet with wound irrigation followed by careful debridement remains the mainstay of treatment of all types of soft tissue injuries.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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## **Dentoalveolar Injuries and Wiring Techniques**

Omkar Anand Shetye

#### **50.1 Defnition**

Dentoalveolar fracture is defned as a fracture in the bone surrounding the teeth without any extension to the basal bones of the maxilla or mandible [1, 2].

### **50.2 Incidence**

Dentoalveolar injuries commonly occur in the age group of 8–12 years. They generally involve teeth, soft tissues, and/or associated bone. Traumatic dental injuries account for a total of 92% of maxillofacial injuries of which 92% involves only the soft tissues and 8% involve the maxillofacial bones [2].

### **50.3 Introduction**

Trauma is the foremost etiological factor that leads to a loss of signifcant number of teeth annually. The recent advancements in the feld of preventive dentistry as well as the development of myriad evidence-based techniques to restore the lost form and function of teeth have made it possible for the dental surgeon to successfully facilitate the improvement in the quality of life of trauma-afficted patients. Time elapsed post-trauma plays a major factor in determining the outcome of the intervention. Apart from reestablishing the premorbid position of the traumatized tooth in its socket, the goal of the treatment is directed toward achieving the pre-traumatic occlusion and intra-arch contour [3].

O. A. Shetye (\*)

### **50.4 Diagnosis and Treatment Planning**

The foundation of diagnosis and management of traumatic dental injuries solely lies on the pillars of a detailed patient history and a clinical examination. **When, Where, and How** forms the "Trauma Triad" of history taking in traumatic dental injuries [4].


History of immediate local measures employed to reduce the severity of injury helps in eliciting information regarding the original condition of the injured area [6].

History of any systemic disorders that may interfere with treatment or post-operative healing including a history of tetanus vaccination has to be obtained before starting the treatment [7].

"Outside-in" examination (examining the facial structure in three concentric rings paying more attention to the innermost ring) helps in achieving the desired management protocol. Level of consciousness should be assessed prior to the clinical examination [6].

The potential for aspiration, airway compromise, and neurosensory defcit warrants the need for a thorough evaluation of all maxillofacial injuries before managing dental injuries [3].

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1013

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_50

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_50) contains supplementary material, which is available to authorized users.

Department of Oral and Maxillofacial Surgery, Goa Dental College and Hospital, Bambolim, Goa, India

In a patient with missing tooth fragment or prosthesis, a chest radiograph and abdominal radiograph may be helpful in locating the missing structures and their management. Owing to its anatomic position, the right bronchus is often the site of foreign body dislodgement [3, 6].

#### **50.5 Clinical Examination**

Clinical examination of the patient has to be divided into the following subsets [8]:


#### **50.5.1 Extra-oral**

Asymmetry of the face following trauma could be due to injury to the facial skeleton or swelling. Areas of ecchymosis and hematoma may indicate fracture of the underlying osseous structure. Laceration, contusion, and abrasion of the overlying skin are common with dentoalveolar injuries (Figs. 50.1, 50.2, and 50.3). Mild antiseptic soap should be used to clean the extra-oral abrasions or a saline wash can be used while being careful to not inoculate injury site further with debris or foreign body [4, 8].

#### **50.5.2 Intra-oral**

Buccal mucosa lacerations should raise suspicion for a Stensen's duct injury. The lips, foor of the mouth, and tongue are areas which are at a risk of being penetrated or sites for secondary injuries [3].

#### **50.5.3 Jaws and Alveolar Bone**

Bimanual palpation of the maxillary and mandibular dentition and evaluation of occlusion should reveal areas of discrepancy or mobility. The direction of dislocation of the apex of primary tooth should be diagnosed since these teeth are in close approximation to the succedaneous teeth. Palpating from the vestibular approach makes this diagnosis easier. Sublingual ecchymosis/hematoma (Coleman's sign) at the foor of the

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.1** Mandibular anterior lingually displaced dentoalveolar fracture with degloving vestibular wound and ragged lip lacerations

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.2** Maxillary anterior palatally displaced and extruded dentoalveolar fracture with associated upper lip injury. Note incisal fractures of the upper lateral incisors (see also Fig. 50.8)

mouth is suggestive of underlying mandibular fractures. Step deformity, crepitation, malocclusion, and gingival lacerations raise suspicion for possible bone defects [7, 9].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.3** Maxillary anterior teeth complete avulsion with associated upper lip injury

#### **50.5.4 Percussion and Pulp Testing**

Percussion test is performed with the end of the handle of an examination mirror. Pain to percussion of a tooth is indicative of damage to the periodontal ligament. Dullness to percussion in one or several adjacent teeth can be indicative of partially luxated teeth or en bloc fracture of tooth or alveolar bone. The percussion test should be started on a non-injured tooth to ensure a reliable response through visual analogue scale [6, 8].

To evaluate the tooth injury thoroughly, pulp vitality is a must. A positive response indicates that the pulp is alive, whereas a negative response indicates that the pulp is dead. Following injury, the tooth may be in a state of shock and may give a false response. Hence pulp testing should also be performed during the subsequent visits to acknowledge the change in response [5].

Electric vitality testing depends on a number of factors including the stage of eruption of tooth, the presence of a restoration or decay, and the ability to isolate the tooth and keep the area clear of blood and saliva [8].

Laser Doppler fowmetry (LDF) is a relatively new pulp testing apparatus. It employs a laser beam directed at the

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.4** Coronal CT image showing left maxillary high dentoalveolar fracture

coronal-labial aspect of the pulp which is scattered by pulp blood cells that in turn produce a Doppler frequency shift. The fraction of light scattered back is detected and processed to elicit a signal. The basic theory is that the pulp revascularization process can be monitored. Studies have shown that in cases in which electrometric tests were negative and LDF displayed vascular perfusion, the LDF accuracy of pulp vitality reached 100% [3].

All the teeth should be tested for abnormal mobility both horizontally and vertically. It should be remembered that primary teeth undergoing physiologic root resorption and therefore always exhibit a certain degree of mobility. The typical sign of an alveolar fracture is the movement of adjacent teeth when the mobility of a single tooth is tested [6].

#### **50.6 Radiographic Examination**

Radiographic techniques are available to evaluate dentoalveolar trauma.

Radiographic examination is essential to determine damage to underlying structures and should include intraoral periapical (IOPA), occlusal, panoramic radiographs (OPG), and cone-beam computed tomography (CBCT) imaging [3, 4].

If conventional CT imaging is done as part of the trauma series, fne axial and coronal cuts will also show the dentoalveolar injuries (Fig. 50.4)

IOPA radiograph provides vital information about root fracture and dislocation of teeth. At times it is diffcult to adequately evaluate a fracture on an IOPA radiograph, due to variations in tube-tooth-flm geometry. Post-treatment radiographs can confrm the proper repositioning of avulsed or luxated tooth into alveolar bone.

Occlusal radiographs provide a larger feld of view, and a steep occlusal exposure is of special value in the diagnosis of root fracture and lateral luxations with displacement of crown [8].

OPG is a useful screening tool and can demonstrate fractures of the mandible and maxilla as well as fractures of alveolar ridges and teeth.

Radiographic evaluation of foreign bodies within soft tissues of the lips and cheeks is done by taking radiographs with the flm placed labial to the alveolus. A reduced radiographic exposure time (approximately 1/3rd of the normal) is used.

CBCT scanning is extremely useful in diagnosis of maxillofacial, alveolar bone, and teeth fractures with the advantage of high-resolution three-dimensional images with low radiation.

The etiology of pediatric and adult dentoalveolar injuries were shown in Box 50.1 and Box 50.2 respectively. Box 50.3 and Box 50.4 represents the classifcation of alveolar bone fracture and classifcation of alveolar bone fracture based on location and displacement respectively.

#### **Box 50.1: Etiology of Pediatric Dentoalveolar Injuries Pediatric patients** [9]


#### **Box 50.2: Etiology of Adult Dentoalveolar Injuries Adult patients**


#### **Box 50.3: Classifcation of Alveolar Bone Fracture: Traumatic alveolar bone** [9]

Type I: Areas surrounding a single tooth

Type II: Entire dentoalveolar segment dislocation

### **Box 50.4 Alveolar fracture can be classifed by their specifc location and movement of displacement** [10]


#### **Box 50.5: Classifcation of Dental Injuries and Surrounding Structure**

#### **Classifcation based on level of involvement** [11]


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.5** (**a**–**c**) Clinical images showing tooth (a) intrusion, (b) extrusion, and (c) avulsion

#### **Box 50.6: Management of Intruded Tooth (Fig. 50.6) Diangelis et al.** [12, 13]

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.6** IOPA showing an intruded upper right canine

#### *Permanent Teeth*

	- Intrusion <3 mm—allow eruption
	- Intrusion between 3 and 7 mm—surgical or orthodontic repositioning
	- Intrusion >7 m m
		- (a) Surgical extrusion with fexible splint for 4–8 weeks
		- (b) RCT using Ca (OH)2 medicament 2–3 weeks after surgical extrusion
	- (a) Wait till the tooth erupts for 3 months
	- (b) Place an orthodontic extruding appliance

#### *Primary Teeth*

Treatment is debatable Immediate extraction of the involved tooth or More conservative approach

#### **50.6.1 Storage and Transportation Media**

If the tooth cannot be reimplanted within 5 min, it should be stored in a medium that will maintain its vitality and periodontal ligament fbers [14–16].

#### **Box 50.7: Principle of Avulsion**


#### **Box 50.8: Primary Management of Avulsion by the Patient**

What the patient can do:


What the patient should not do:

• No effort should be made to mechanically cleanse the root of the tooth because this would damage the remaining periodontal ligament.

Transportation media for avulsed teeth include


Commercial products are designed especially for storing avulsed teeth. It has shelf life of 2 years without refrigeration (Box 50.9).

3. Milk: is a readily available medium. It is the medium of choice in the absence of hanks balanced salt solution or viaspan. Milk will only prevent further cellular demise and is used specifcally when the teeth has been outside the oral cavity for less than 20 min.

#### **Box 50.9: HBSS Contents**

Contents of Hanks balanced salt solution [19]


*Morus rubra* (red mulberry), egg white, coconut water, rehydrating solution like Gatorade and ricetral, lens solution, probiotic solutions, saliva offcinalis, honey milk, and ascorbic acid have been used as a transportation medium for avulsed tooth.

#### **50.7 Treatment at the Clinic**

Traumatically avulsed teeth when out of the mouth for a short period should be reimplanted as soon as possible.

#### **Box 50.10: Reagent for Root Surface Therapy**

Agents used for root surface treatment to prevent resorption


After normal reattachment, survival is prolonged. Avulsed teeth which remain out of the mouth for more than 2–3 h generally resorb rapidly and should not be reimplanted indiscriminately.

The outcome of replantation depends on the stage of root development and extra-oral time. If the avulsed tooth has a closed apex and extra-oral time is less than 60 min (early replantation), the reimplanted tooth will have the best prognosis. The ideal time to begin root canal treatment is within 10–14 days post-replantation and before splint removal.

There is a statistically signifcant association between extirpation within 14 days and an increased likelihood of successful periodontal healing and prevention of external infammatory root resorption.

It is generally agreed that Ca (OH)2 has a benefcial effect in the outcome because of its antibacterial properties, ability to dissolve necrotic tissue, and its ability to prevent or control infammatory resorption. The anti-infammatory and antibacterial action may decrease root resorption by directly inhibiting resorptive cells (Box 50.10).

#### **50.7.1 Delayed Replantation (more than 60 min)**

Delayed replantation of avulsed tooth with closed apex has a poor long-term prognosis. The periodontal ligament gets necrotic and healing is delayed. The goal of delayed replantation is to promote alveolar bone growth so as to encapsulate the reimplanted tooth. The eventual outcome is ankylosis.

In children below age of 15 years, if ankylosis occurs and when the infra position of the tooth crown is more than 1 mm, decoronation is recommended to preserve the contour of the alveolar bone.

Root canal treatment (RCT) can be carried out on a tooth prior to reimplantation or it can be carried out within 14 days of reimplantation. The tooth is immersed in 2% sodium fuoride solution for a minimum of 5 min up to 20 min.

Avulsed teeth having open apices and extra-oral time less than 60 min are also reimplanted and stabilized for 7–10 days and up to 2 weeks. The goal of reimplanting developing (immature) teeth in children is to allow for possible revascularization of the tooth pulp.

If there is evidence of the pulpal infection or infammatory response, the pulp should be removed and Ca (OH)2 placed immediately, aiming to stimulate apexifcation and halt the infammatory process.

It is believed that delayed replantation of avulsed teeth with open apices have a poor long-term prognosis. The periodontal ligament gets necrotic and is not expected to heal. Osseous replacement, resorption, or ankylosis will occur. Therefore some authors have concluded that such teeth should not be reimplanted.

The recent guidelines recommend replantation to maintain alveolar ridge contour as ankylosed roots get transformed to bone during the remodeling process. RCT can be performed on the tooth prior to replantation through an open apex (Fig. 50.7a–c).

#### **50.7.2 Stabilization**

**b**

Stabilization of an avulsed tooth can be achieved using a variety of materials like wires, arch bar wired to the teeth,

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.7** (**a**–**c**) Shows a case of avulsed upper right central incisor in a 24-year-old man, which presented after few hours of avulsion. The tooth was transported in milk by the relatives. A RCT was carried out and the tooth reimplanted and stabilized with wire and composite splint (**a**, IOPA showing avulsed incisor; **b**, IOPA with tooth reimplanted; **c**, shows the clinical image after splinting)

**a**

**c**

orthodontic band and brackets attached by acid etch technique, combined with orthodontic band and acrylic appliance, or periodontal pack.

They are generally maintained for 7–10 days after replantation to allow gingival reattachment.

Studies by Andreason [20] (1985) have shown that prolonged splinting may be inadvisable because it enhances ankylosis.

The socket should be left undisturbed before replantation. If the alveolar bone has collapsed, a blunt instrument should be inserted carefully into the socket in an attempt to reposition the wall. It should be lightly aspirated if a blood clot is present.

In general, stabilization for reimplanted teeth is required for 7–14 days. The periodontal ligament fbers should have healed suffciently after the frst week to remove the splint. However, the patient should be advised not to bite directly on the reimplanted tooth for 3–4 weeks after injury.

#### **50.7.3 Technique**

#### **50.7.3.1 Wire Acid Etch Composite Splint**

A wire of moderate stiffness (round 0.030 in. stainless steel) is adapted to the facial surface at least one or more stable teeth on either side of the reimplanted teeth.

The physiologic movement imparted to the reimplanted tooth during function is increased when fewer teeth are included in stabilization of the avulsed tooth.

The facial surface of the avulsed and adjacent teeth is acid etched, and wire is cemented to them with composite.

The wire is generally curved along the middle third of the labial surface of the teeth. 90° terminal bends toward the gingiva are made at the labiodistal angles of the most posterior teeth to be splinted in order to avoid sharp edges and stability. The terminal ends should be about **2 mm** long to reduce the possibility of lateral displacement of the wire [21, 22].

#### **Splinting periods for traumatic dental injuries** [6]


#### **50.7.4 Complications**

	- (a) Surface replacement
	- (b) Replacement resorption (ankylosis)
	- (c) Soft tissue replacement [23]

#### **50.8 Alveolar Process Fracture**

Fracture of the alveolar process usually involves the teeth.

Open reduction/ raise the fap if reduction not possible (Fig. 50.9 a, b)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.8** Shows the case in Fig. 50.2, which has undergone closed reduction and fxation by arch bar. Full intrusion and reduction was not achieved. The occlusal discrepancy was planned to be corrected later by RCT and necessary prosthetic work

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.9** (**a**, **b**) Shows a case of high alveolar process fracture segment in the maxillary right side with associated split between central incisors. Under GA, the extruded displaced alveolar segment was repositioned after placement of split arch bars and bridle wiring between the central incisors. The segment was fxed with mini plate and screws, taking care not to injure the tooth roots. Due to root anatomy, only a single plate was fxed after reduction. Post-operative IMF was given for 2 weeks, for additional stability and to help the healing process

### **50.9 Management of Dentoalveolar Fracture**

The goals of treatment should be:


#### **50.9.1 Treatment Options**


Model surgery on the plaster models is performed to recreate the normal anatomic relationship of the fractured segment and allow fabrication of accurate splint [9].

#### **50.9.2 Specifc Treatment Options**

Class I fractures that involve a non-displaced, edentulous alveolar segment often do not require treatment other than a soft diet and observation. If there is concern about the stability of the fracture during the healing process, stabilization may be used.

Class II fractures that involve a displaced dentulous segment and need reduction may require a great deal of force to realign the fractured segment. Posterior fragments are always displaced to the lingual area. Large forceps may be helpful to apply a force suitable to reduce the bony fragment. Reduced fragments are held in place by MMF or splints.

Class III fractures of a moderately or severely displaced dentulous segment may be too diffcult to reduce adequately. There may be scant room into which the irregular, displaced segment needs to be replaced. It may be necessary to burr or rasp down the displaced segment or the opening in the remaining bone to successfully reduce the fracture. This is usually accomplished by use of a power drill with a suitable size bur or a fne rhinoplasty rasp. The amount of tissue that is removed should be limited so that the suffcient bone to bone contact remains for bony union as the fracture heals. Maintenance of class III fractures in a reduced fashion may be accomplished with arch bars, MMF, and/or variety of splints.

Class IV fractures that extend into one or more non alveolar fracture lines are usually less challenging than class III fractures because (1) the bone segments are larger, (2) the treatment of the associated fractures gives excellent exposure, and (3) usually no barrier exists to reduction. Plates, screws, arch bars, MMF, and/or variety of splints may be used [7].

#### **50.9.3 Wiring Techniques**

In MMF, wires are passed interdentally between teeth in both the jaws followed by tightening of these wires together in a cross arch fashion which serves to stabilize the fracture segments.

Over the period of last century, MMF techniques have evolved dramatically, and more recently, many more easier and effective methods have been introduced like MMF screws, eyelet wiring, and Erich arch bars to name a few. Although it is a quick and effcient way of securing MMF, yet, this technique is criticized for extended periods the patient needs to be closed mouth, diffculty in maintaining oral hygiene, lack or defcient nutritional support via oral route and inability to use this treatment modality in medically compromised patients like epileptics or in immediate post-operative period due to increased risk of aspiration.

#### **50.9.4 Armamentarium and Principles**  (Fig. 50.10)

A soft stainless steel wire of 0.35–0.5 mm diameter is utilized and pre-stretched to 10% of its original length to prevent loosening of wire once tightened. Overstretching beyond this point should be avoided as this will make the wire brittle and susceptible to breakage.

#### **50.9.5 Principles**

Basic principles to be followed are [25]:


#### **50.9.6 Technique**

#### **50.9.6.1 Bridle Wire** [26, 27]

First advocated by Hippocrates, bridle wire remains one of the oldest yet a conventional method of treating mandibular fractures. This technique represents a temporary way of stabilizing the fractured segments, preventing them from faying apart.

Advantages include stabilization of the two fractured segments preventing further damage to the adjacent soft tissues, maintenance of the airway patency (especially advan-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.10** Armamentarium for wiring

tageous for the fractures of the anterior mandible), decrease pain, and reducing damage to the neurovascular bundle from immobilizing the fractured fragments, thereby preventing gross movements and also decreasing muscle cramping.

#### **Technique**

Following administration of local anesthesia , a 24–26 gauge wire is passed around the neck of the teeth adjacent to the fracture site on either side (Fig. 50.11a). With both ends being secured in the wire holder (Fig. 50.11b), the fractured segments are manually reduced anatomically, and the wire is tightened in a clockwise fashion till further reduction is achieved (Fig. 50.11c), and the fracture is stabilized

## **50.9.6.2 Gilmer's Direct Interdental Wiring**

[26, 27]

This technique represents an easy and fastest method of immobilization.

#### **Technique**

A 15 cm pre-stretched wire is passed through the interdental embrasure of the tooth on one side from buccal to lingual. This wire will pass around the tooth and emerge out buccally through the interdental embrasure from the other side. Both ends are held together and twisted to achieve a 3 cm tail (Fig. 50.12a–c). Multiple teeth (at least 5–6) in either jaw are utilized. Following manual fracture reduction and placement of teeth with premorbid occlusion, the tails from opposite arch are twisted together in a cross arch or zigzag fashion to achieve immobilization (Fig. 50.12d). The cut ends of the tail are secured into the interdental spaces. Once all the wires/tails are twisted, complete immobilization is achieved.

The only drawback of this technique is that, in cases of broken /loose wire, all the cross arch wires will have to be removed and redone post placement of twisted wire.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.11** Shows sequential steps bridel wiring. (**a**) Passing of the wire through the tooth embrasure. (**b**) Formation of the wire loop assuming the fracture line is between the two premolars. (**c**) Twisting of both the ends to stabilize the fracture

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.12** (**a**–**d**) Shows technique of direct Gilmer wiring. Formation of the loop around the tooth in the lower and upper arch followed by twisting both the wires together in order to achieve MMF

#### **50.9.6.3 Interdental Eyelet Wiring (Ivy Loop Method)** [26, 27] (Video 50.1)

Yet another easy and quick method of securing MMF was advocated and popularized by Dr. Robert H.Ivy, Philadelphia, USA.

#### **Technique**

A pre-stretched 26 gauge/0.35 mm diameter wire was made into an Ivy loop utilizing the middle segment of the wire by twisting it around a metallic rod of 3 mm diameter. 3–4 turns are given to achieve adequate stability to the loop. Both the ends of the wire are then cut in an oblique fashion (Fig. 50.13a).

Both the ends are passed through the interdental space to emerge lingually/palatally so that the loop lies buccally (Fig. 50.13b). Following this, one end of the wire is passed from distal interdental space of the same tooth to emerge buccally. This same wire is passed through the loop and secured to the other end of the wire which is passed mesially from the lingual/palatal side to the buccal side of the adjacent tooth side (Fig. 50.13c,d) . Both the ends are tightened (Fig. 50.13e), and the tail end cut short and secured into the dental space mesially to prevent damage to the adjacent soft tissues.

Stability of the MMF is based on the adequate number of Ivy loops placed in both the arches and secured.

In the maxillary arch, loops can be placed between two molars, two premolars, or between lateral incisor and canine or two central incisors. In the mandibular arch, loops are best placed between two molars, two premolars, or between lateral incisor and canine.

#### **Modifcations**

1. In 1975, Hallam modifed the Ivy loop by addition of another loop proximal to the frst for the purpose of ligature/tie wire (Fig. 50.14)

Although an interesting modifcation yet the disadvantage observed was that due to increase in length and in patients with short vertical dimension, both the proximal loops would meet one another making the placement of MMF extremely diffcult.

2. **Clove hitch**

This technique helps in placement of an Ivy loop in cases of missing teeth or a single isolated tooth. It is the easiest way to secure MMF where placement of an arch bar or any other technique of securing MMF is diffcult due to lack of supporting teeth.

#### **Technique of Clove Hitch**

The one end of the wire that has an Ivy loop forms a loop around the lone-standing tooth (Fig. 50.15a) . Continue the wire around the tooth forming another loop for the second time (Fig. 50.15b) . The end of the wire is under the frst loop (Fig. 50.15c), and both the ends of the wire are pulled together and tightened (Fig. 50.15d).

#### **50.9.6.4 Continuous or Multiple Loop Wiring**  [26, 27]

It was frst described by Col. Stout in 1943. It represents an easy and simple technique which requires minimal instrumentation. This technique utilizes multiple loops on the buccal surface of the tooth which can be used for both MMF using wire as well as elastic traction for the purpose of fracture reduction. One major advantage of this technique is the use of differential traction force that can be achieved and applied for fracture reduction before securing it with wires for MMF.

#### **Technique**

A 30 cm-long pre-stretched wire is placed on the buccal side of the teeth with the anterior end placed as anteriorly as possible while the posterior end extending up to the last tooth to be used. The wire is passed through the interdental space of the posterior most teeth and emerged through its mesial side. The wire is then passed over the buccal wire and passed back into the same interdental space. A 3 mm diameter rod can be used parallel to the buccal wire for adequate loop diameter as well as uniformity of the loop (Fig. 50.16a). Once the wire is passed back through the same interdental space, it then emerges out from the mesial interdental space of adjacent tooth (Fig. 50.16b). This continues till the anterior most teeth where both the ends of the wire are twisted together, cut, and placed into the interdental space (Fig. 50.16c,d). Each loop is then twisted, and loops are made of uniform diameter. In cases of securing MMF, the loops are turned toward the occlusal surfaces of the teeth, but in cases of elastic traction, they are turned in the opposite direction toward the gingiva [27].

#### **Modifcation**

This technique needs modifcation when some teeth are missing. Herein, once the loop at the mesial end of the tooth adjacent to the missing tooth is formed, both of the free ends of the wires are held together and twisted till the distal end of the next tooth. Once the desired length is achieved, the loop is again formed at the distal end, and the looping continues till the anterior most teeth.

#### **50.9.6.5 Risdon's Wiring** [26, 27]

#### **Indications**

It is an alternative to an arch bar for a fractured mandible that needs fxation.

#### **Technique**

A 25 cm-long wire is passed through the posterior most tooth in the quadrant to emerge bucally, followed by twist-

**Fig. 50.13** Shows steps in Ivy loop technique. (**a**) Photograph of an Ivy loop. (**b**) Both the ends are held together an passed through the tooth embrasure of the premolar and molar. (**c**) One end passed is passed through the mesial of premolar and other through the distal of

molar to emerge buccally. (**d**) Distal end is passed through the loop on the buccal side to emerge mesially. (**e**) Both the ends of the wire are held together and twisted

©Association of Oral and Maxillofacial Surgeons of India

```
Fig. 50.13 (continued)
```
©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.14** Shows a modifcation of Ivy loop

ing the wire up to its full length till the midline (Fig. 50.17a). Another wire is passed from the opposite quadrant of the same arch and twisted in a similar manner. Both the ends of this twisted wire are tightened at the midline after reducing the fracture segments (Fig. 50.17b,c). Once anatomic reduction is achieved, additional wires are used to stabilize this long wires by passing around the embrasures of the teeth and looping around the wire segment (Fig. 50.17d) [26, 27].

#### **50.9.6.6 Obwegeser Wiring** [26, 27] **Technique**

This technique utilizes a 30 cm-long wire that is bent into a continuous "W" arcade form as depicted in Fig. 50.18a. The elevated portion of the arcade acts to form the loop, whereas the depressed portion adapts to the contour of the teeth palatally or lingually. The distal end of the wire arcade is kept long enough so that it will follow the buccal contour of the arch, when it is passed through the interdental space of the most posterior tooth from lingual/palatal to buccal side. The elevated ends of the

**Fig. 50.15** Showing clove hitch technique. (**a**–**c**) Single loop is passed around the lone-standing tooth followed by second loop under the frst one, pulling both the ends together. (**d**) Showing clove hitch wiring technique

arcade have a ligature wire attached to it (Fig. 50.18b), which only suffices the arcade to be pulled through to the interdental space to emerge buccally (Fig. 50.18c,d). The long wire is then passed through this loop (Fig. 50.18e), and a modified hemostat is used to twist this wire to form uniform loops. At the mesial end, both the ends of the wire are held together and twisted (Fig. 50.18f). The loops can be used for both elastic traction and wires for securing MMF.

The disadvantage of this technique is that it is very cumbersome and adequate expertise is needed to carry out this technique.

**Fig. 50.16** (**a**, **b**) Showing continuous or multiple loop wiring technique, a rod is held parallel to the buccal surface of the teeth, and the wire is passed through the distal most tooth embrasure to emerge buccally and looping around the rod. (**c**, **d**) Continuous loops till the midline are made followed by pulling the buccal rod out to achieve loops

#### 50 Dentoalveolar Injuries and Wiring Techniques

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.17** (**a**, **b**) Showing steps in fabrication of Risdon wiring. Distal most tooth is used to loop the wire and twist it. (17c) Showing twisted wire in the midline. (**d**, **e**) Showing wires passed through teeth embrasure to loop around the main wire. (**f**) Alternate method of securing the long wire

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.18** (**a**, **b**) Showing fabricated W arcade used in Obwegeser technique. (**c**) Showing ligature wire pulled from the palatal/lingual side to buccal side. (**d**–**f**) Showing wire from the distal most end passing though the loops to be twisted at the most medial end of the arcade

#### **50.9.6.7 Arch Bar** [26, 27] (Video 50.2)

Commercially available arch bars are usually customized or prefabricated. In most clinical scenarios, prefabricated arch bars like Erich's, Jelenko, Winter's, or Schuchardt's suffce the need for placement.

#### **Indications**


#### **Technique**

Ideal placement is as close to the interdental spaces, which are then secured with 26 gauge wire. This close placement helps to reduce the arch bar to tooth contact and allows for better adaptability of the arch bar to the arch contour, thereby reducing loosening of arch bar.

In most cases, arch bars are placed from distal of frst molar, in one quadrant to the other, maintaining a minimum of two teeth on either side of the fracture line in a dentate patient.

The wire is passed from one interdental space and moved around the tooth to emerge buccally from the other side (Fig. 50.19a). Placement of arch bar by securing it with wire begins (Fig. 50.19b) usually at the midline and proceeds posteriorly or from one end (molar) to another (Fig. 50.19c,d) in order to avoid excess in the center and to achieve uniformity throughout the length of the arch bar. The wires are usually twisted in between the cleats and placed into the interdental space to avoid damage to surrounding soft tissues.

The cleats of the arch bar always face gingivally. MMF is usually secured using 24 gauze wires in box pattern.

Figure 50.19e is showing a model with upper and lower arch bar placement secured with wires, while Fig. 50.19f is showing a clinical photograph of arch bar placement.

#### **Advantages**


#### **Disadvantages**

• One of the major drawbacks is the lack of vertical stop in the anterior region when an arch bar is used. In the posterior region, the opposing teeth act as a vertical stop for occluding teeth which isn't the case with anterior region as the anterior upper teeth may slide over the lower when elastics are stretched between the maxillary and mandibular teeth resulting in extrusion of anterior teeth. This problem can be circumvented, by drilling a hole using a bur in the gingival area apical to the mucogingival junction through the buccal and lingual cortices.

An additional 24 gauze wire is passed from the buccal side of this hole to emerge lingually. The lingual end of the wire is then passed through the interdental space of the tooth to emerge buccally. Both the ends of the wire are then twisted to prevent extrusion.

In the anterior maxilla, anterior nasal spine can be used for additional suspension of the arch bar to prevent downward pull exerted by the elastics.


#### **Complications**

Post reduction of the dentoalveolar fracture, the incisal edges of the fractured teeth bearing segment will remain above the normal occlusal plane. This discrepancy can be corrected by application of apical pressure to this segment through MMF, circummandibular wiring, suspension from ANS, lateral piriform, buttress, or using the eye of the maxillomandibular fxation screw.

#### **50.10 Maxillomandibular Fixation (MMF) Screws** [28] (Video 50.3)

#### **50.10.1 Introduction**

A self-drilling or tapping maxillomandibular fxation screws by Arthur et al. [29] in 1989 reduced the intra and postoperative problem associated with the arch bars.

#### **50.10.2 First Generation**

Screws were modifed monocortical self-tapping screws that were kept at 4–5 mm above the mucosa for subsequent wire

**Fig. 50.19** (**a**–**d**) Showing technique of arch bar placement. The wire is passed through the embrasure or emerge buccally. The wire on the mesial side of the tooth is passed above the arch bar, where as the distal end wire

is passed below the arch bar to secure it by twisting. (**e**) Showing a model with upper and lower arch bar placement secured with wires. (**f**) representing a clinical photograph of arch bar placement

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.19** (continued)

splinting. Surgical preparation of the site needed prior to insertion. They were usually wider in diameter with grooves/ futes.

#### **50.10.3 Second Generation**

Screws were self-drilling or self-tapping screws which were spool shaped. The central part of the screw head is perforated with one of two channels perpendicular to its axis aiding in the passage of ligature wires. The top of the screw heads is smoothly fnished at the contact zone with overlying mucosa.

Clinician should consider fracture location, dentition, surgical exposure, and the quantity of bone for placement of these IMF screws.

Ideal radiographic images obtained are orthopantomogram and CT axial scan to analyze and plan placement of these screws.

Sites include anterior vestibule and anterolateral (canine and premolar regions) as they provide suffcient bone depth, clearance from adjacent tooth, and easy accessibility. Screws should be placed above the root apices as subapical placement leads to mucosal overgrowth (Fig. 50.20a–d).

Ideally one screw should be placed on either side of the fracture line. However, in severely displaced cases, it is advisable to use multiple screws on either side to achieve vectors in different directions.

#### **50.10.4 Advantages**


#### **50.10.5 Disadvantages**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 50.20** (**a**–**d**) Showing clinical steps in placement of MMF screw. Technique for placement of MMF screws. Marking is done between the root apices followed by drilling and placement of MMF screw, one in each quadrant. The wire is passed through the eye of the opposing arch and secured to achieve intermaxillary fxation

#### **50.11 Conclusion**

Dentoalveolar fracture mostly involves teeth, soft tissues, and associated bones. With the recent advancements in the feld of dentistry, the oral and maxillofacial surgeon can restore the lost form and function of teeth to facilitate the improvement in quality of life in traumaafficted patients.

**Acknowledgments** For Figs. 50.1, 50.2, 50.3, 50.4, 50.6, 50.7, 50.8 and 50.9 to Suvy Manuel.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Principles of Internal Fixation in Maxillofacial Surgery**

Abhilasha Yadav

### **51.1 Introduction**

Road traffc accidents (RTA) are one of the primary etiologies of craniomaxillofacial fractures. Open reduction and internal fxation (ORIF) is the most important treatment modality to restore the compromised form and function. Adequate reduction and fxation with miniplate osteosynthesis is the essential component of management.

### **51.1.1 Association of Osteosynthesis (AO Principles)**

The following are guidelines for internal fxation based on the four basic principles formulated by AO in 1958.


### **51.2 History**


According to him, there was a need for compression between the fragments of fractures. He used a plate called coaptens to achieve this goal, which increased stability and suppressed interfragmentary motion. The mode of healing initiated by this is called soudure autogene (autogenous welding) now known as primary bone healing.

6. In 1967, mandibular compression screw (MCS) was used in oral and maxillofacial surgery (OMFS) in edentulous fractured mandible while performing frst compression osteosynthesis. Self-tightening/automatic MCS plate was developed by Luhr in 1968. Later, dynamic plates were advocated for surgery of long bones with subsequent application in mandibular fractures.

**51**

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1039 K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_51

A. Yadav (\*)

Department of Oral & Maxillofacial Surgery, Awadh Dental College & Hospital, Jamshedpur, Jharkhand, India

1881 Glimer On either sides of the fracture, two heavy rods 1886 Hansmann Retrievable bone plates 1945 Christiansen In mandibular fracture-tantalum plates 1956 Bagby First compression plate 1960 Luhr and Mittlmeir Improved mandibular compression plates 1969 AO/ASIF Dynamic compression plates (DCP) 1970s Brons and Boeriing Lag screws 1973 Schmoker and Spiessel (EDCP) eccentric dynamic compression plates 1973 Michelete Miniplates 1975 Champy Monocortical screws principal for fxation 1977 Luhr Compression plates for the frst time in management of fracture mandible 1977 Spiessel For mandible fracture advocated AO/ASIF principle 1989 Bos Resorbable plates and screws 1994 Dynamic compression plate with locking compression plate 2011 Development of locking compression plate with combination holes

**Table 51.1** History of development of fracture management modalities

#### **51.2.1 Evolution of Fixation Methods**

History of development of fracture management modalities [2–4] (Table 51.1)

#### **51.3 Concept of Bone Healing**

#### **51.3.1 Secondary Bone Healing** (Fig. 51.1)

#### **51.3.1.1 Stage I: Infammation Induction**

Immediately after fracture, hematoma formation occurs; hematoma plays a vital role in the angiogenesis of the healing fracture. Subsequently, infammatory cells, stem cells, and fbroblasts initiate infammatory response and enhance angiogenesis. Cytokines which helps in bone repair are released in this phase and hematoma is removed. Within 3 days, thin layer of fbrous tissue covers the periosteal surface of fractured bone. The cortical bone adjacent to fracture site becomes necrotic which later gets remolded by multinucleated osteoclast.

#### **51.3.1.2 Stage II: Fibrocartilaginous (Soft) Callus Formation**

Dense fbrous tissue, cartilage, and fbrocartilage formation occurs due to organization of subperiosteal hematoma; soft callus is composed of internal (endosteum of marrow cavity and lining of Haversian canal) and external components (periosteum and organizing hematoma) and continued proliferation of osteoblasts; fbrocartilaginous tissue begin to calcify as the periosteal and endosteal circulation develops. The conversion of chondrocytes to osteocytes occur and the entire callus is converted to immature woven bone.

#### **51.3.1.3 Stage III: Hard Callus Formation**

After 3–4 weeks of fracture, the hard callus begins to form and osseous union of the fractured cortical bone starts.

#### **51.3.1.4 Stage IV: Remodeling**

The trabeculae orient themselves in the direction of functional pressures after bone formation.

#### **51.3.2 Primary Bone Healing (Contact and Gap Healing)**

Healing without callus formation is called as primary bone healing. When there is direct apposition of cortical bone surfaces, contact healing occurs. Osteoclasts widen the Haversian canals on either side of the fracture and move toward each other. The cortical bridging occurs in 8 weeks and is usually completed in 16 weeks. In gap healing also primary bone healing occurs; gap as wide as 100 μm can be flled with mature lamellar bone (Fig 51.2).

#### **51.4 Biomechanics of Facial Skeleton** [5]

#### **51.4.1 Mandible Fractures**

The mandible is a class III lever with:


Simple beam mechanics described the traditional biomechanical properties of mandible, which represents compression at inferior border and tensile forces on the superior border with an applied anterior load (Fig. 51.3). The "neutral axis" is the line of zero stress where the tensile forces become compressive, and it is approximately at the level of the inferior alveolar canal. Compression and tension will be produced in symphysis region due to torsional forces.

The muscles inserting on the mandible and forces exerted by these muscles during function, determine the tension and compression zone in cases of fracture mandible.

The direction of the muscular forces acting on the mandible by temporalis, lateral pterygoid, pterygomasseteric sling, and suprahyoid musculature is shown by arrows in Fig. 51.4. For successful treatment of facial fractures in the form of rigid fxation, the understanding of biomechanics of facial injury is very important.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 51.2** Contact and gap healing (arrow denotes contact healing)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 51.3** Tensile and compressive force mechanism

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 51.4** Direction of muscular forces

#### **51.4.2 Midface Fractures**

Midface generally does not show muscle forces acting on them except for zygomatic bone, on which masseter exerts the primary force which can create notable bony displacement causing inferior and medial displacement especially in the presence of temporalis fascia disruption (Table 51.2).

**Table 51.2** The four articulations of zygoma with their functions in management of fracture


#### **51.5 Functions of Plates**

#### **51.5.1 Compression**

Compressing together the main fragments of a single plane fracture can result in absolute stability, i.e., the complete abolition of interfragmentary movement. Interfragmentary compression in single plane, as in diaphyseal fractures, can be achieved by exploiting the eccentric loading capabilities of the dynamic compression family of plates.

The screw is inserted in a neutral mode, and plate was fxed to the right-hand fragment. In an eccentric (load) mode, a screw is then inserted into the left-hand fragment. As the load screw is fully inserted, it engages and slides down the sloping surface of the plate hole, and the screw and bone move toward the fracture, compressing it.

If the plate that exerts axial compression is exactly contoured to the anatomically reduced fracture surface, there will be some gapping of the opposite cortex when the plate is tensioned by tightening the load screw. This is due to the compression being maximal immediately beneath the plate and not evenly distributed over the whole area of the fracture plane. The solution to this problem is to "overbend" the plate so that its center stands off 1–2 mm from the anatomically reduced fracture surface. Slight gaping of the cortex will occur directly underneath the plate when the neutral side plate is applied to the bone. The tightening of load screw causes tension in the plate and compresses the fracture evenly across the full diameter of the bone.

#### **51.5.2 Neutralization**

A primary lag screw fxation, exerting interfragmentary compression, can be vulnerable to disruption by physiological bending and/or rotational forces. Such a primary fxation is usually protected by the use of a plate, spanning from one main fragment to the other—this "neutralizes" the disruptive forces. All such forces are then transmitted via the plate and bypass the primary lag screw fxation.

#### **51.5.3 Tension Band**

If a body with a fracture is loaded at each end, over a bending point (fulcrum), tension (distraction) forces are generated, maximal on the side opposite the fulcrum, and angulation occurs. However, if an inelastic band, such as a plate, is anchored to the tension side of the body, same load will generate compression across the fracture interface. This is known as the tension band principle.

#### **51.6 Fixation Methods and Devices** [6] (Table 51.3)

Commonly used devices used for fxation are wires, staples, pins, and screws [6].

#### **51.6.1 Material**

Most commonly used materials are titanium (Ti-6Al-4V) and stainless steel (316L). Stainless steel has been used because of its greater biocompatibility and corrosion resistance. Since 1980 titanium was used in maxillofacial surgery.

#### **51.6.2 Rigid Fixation**

The internal fxation is defned as the placement of wires, plates, screws, rods, pins, and other hardware to stabilize the fracture fragments.

#### **51.6.2.1 Rigid Internal Fixation (RIF)**

RIF is defned as "bone fxation of any form in which biomechanical forces are either countered or used to stabilize the fragments of fracture and permits loading of bone to permit active action" [7].

#### **51.6.2.2 Examples of RIF**

Examples of RIF are the use of bone plates and screws, two lag screws, and use of reconstruction plate with three screws on each side of the fracture fragment. Use of long compression plate is also included in the rigid internal fxation examples.



*Healing*: In the rigid internal fxation, no callus formation is formed during bone healing. The fracture bones heal by a process of Haversian remodeling. This primary or direct bone union requires immaculate immobilization between osseous fragments, i.e., minimum gap between the rigid fxation. Examples of rigid fxation for fracture mandible are shown in Fig. 51.5a,b.

#### **51.6.3 Nonrigid Internal Fixation**

It is a kind of fxation that is not strong enough to prevent interfragmentary motion completely. Thus interfragmentary motion is the differentiating factor between rigid and nonrigid fxation. Any mobility between fragments stabilized through internal fxation on active usage of skeletal structure signifes nonrigid fxation.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 51.5** (**a**, **b**) Techniques of rigid fxation for mandibular fracture. (**a**) Fixation with single miniplate and tension band; (**b**) fxation with two miniplates

Transosseous wiring across a fractured mandible is a good example of nonrigid fxation. The wire is unable to neutralize torsion/or shear forces and requires other fxation methods like MMF (maxillomandibular fxation).

*Healing*: The bone healing that occurs under the condition of mild mobility between fragments is called as secondary bone healing. There is deposition of periosteal callus in such circumstances, followed by resorption of fragment peripheries and tissue differentiation through various stages from fbrous to osseous healing.

#### **51.6.4 Semirigid Fixation**

Semirigid fxation is based on load-sharing osteosynthesis. Semirigid fxations include the use of:


#### **51.6.5 Load-Bearing Versus Load-Sharing Fixation** (Table 51.4)



#### **51.7 Classifcation of Plating System** [8]

	- (I) Mandibular compression screw system
	- (II) Mini system
	- (III) Micro system
	- (IV) Mandibular reconstruction system
	- (II) Reconstruction plates

#### **51.7.1 Locking Plate-Screw Systems**

In the late 1950s, AO group put forth the tenets which are followed in traditional plates and screws. This included exposure of fracture with anatomic reduction and internal fxation of fracture fragments with the desired result of anatomic bone union [9]. The stability of these plates is achieved by locking the plates by the screws.

Conventional screw – bone plates system requires plate to adapt precisely. In the absence of this contact, the tightening of screw will draw the segments of the bone toward the plate which results in change of the occlusion and bony segments.

On the other hand, the locking plate-screw system does not require the intimate contact of plate to the underlying bone in all the areas. The screw tightening locks the plate and thus stabilizes the bone segments without compressing the bone to the plate. Alteration in reduction is impossible after screw insertion.

According to Herford and Ellis [10], the locking plate and screw system are simple to use. Like compression plate it does not require plate to be compressed to the bone.

Klotch et al. [11] also concluded that the locking plates require less time due to less bending and faster application with good results.

Locking plate and screw come in two designs, i.e.:


The threaded locking plate - screw system features corresponding machined threads incorporated in both the screw and plate. Whereas, the tapered locking screw - plate system has a screw head which is tapered in shape with machined threads, with the plate either having no machined threads or a single machined thread incorporated into its design. This facilitates a more fexible locking mechanism which allows for screw angulation of upto 10 degrees, in comparison to the threaded locking system which needs absolute perpendicular screw placement [12].

#### **51.7.2 Reconstruction Plates**

The rigid plates with 2.7 mm bicortical screws were introduced by AO/ASIF in 1972 [13].

The main advantage attributed to the non-locking reconstruction plate, is its "load bearing" principle. Scolozzi and Richter [14], used the 2.4 mm AO Titanium plates for the management of mandible fractures, with good outcomes and very less complications.

They are available in different shapes for specifc areas like angle reconstruction plate (Fig. 51.6), condylar reconstruction plate (Fig. 51.7), and straight reconstruction plate with different lengths.

#### **Indications**


The advantages of rigid fxation with grafting include immediate jaw function and excellent stabilization of graft. The main disadvantage at the graft site is disuse osteoporosis or "stress shielding." This phenomenon occurs when rigid plates absorb the mandibles functional stress. To protect the long bones from stress, the plate's modulus of elasticity will have to exceed in comparison with the bone to which it is attached. Osteoporosis and reduction in bone strength are the result of protection from stress or shielding in long bones [15].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 51.6** Angle reconstruction plate

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 51.7** Condylar reconstruction plate

#### **51.7.3 Lag Screw Fixation**

In oral and maxillofacial surgery, Brons and Boeriing introduced lag screw fxation for the frst time in 1970. According to them two lag screws prevent rotational movements of the fracture fragments in oblique mandibular fractures [16].

#### **51.7.3.1 The Principle of Lag Screw**

The lag screw principle is used whenever two wide contact surfaces of the bone should be pressed together (for mandibular oblique sagittal fractures or onlay graft fxation).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 51.8** Orthopantomogram showing fxation with lag screws

Through the outer cortex or onlay graft, the drilling of the hole was carried out of the identical diameter to that of screw so that the screw slips through the outer cortex. The lag screw drill, which is of the same diameter as the screw, will simultaneously create a conical countersink to provide an optimal ftting of the screw head. The inner cortex is then perforated with the normal surgical drill, and the screw is inserted. It grips the inner cortex and, when tightened, exerts great force to pull the outer segment into close contact with the inner one. This principle can be used in oblique sagittal mandibular fractures, with the placement of at least three screws, or in combination with the plate, lagging only one or two of the total minimum number of screws (Fig. 51.8).

#### **51.7.3.2 Absolute Rigid Fixation Provided by Lag Screw**

Lag screw should be selected in patients having suffcient bone available for placement of two screws; dissolution of the bone around the screws results in cases of micromotion. The lag screw should be placed in the direction perpendicular to the line of fracture to avoid displacement or overriding during tightening of the screws.

Advantages of lag screws over bone plates:


#### Disadvantages

As the lag screw fxation relies on compression of bone fragments and if intervening bone is unstable due to comminution or missing, there will be segment overriding or fracture gap shortening, resulting in malocclusion.

#### **51.7.4 Comparison of Lag Screw Fixation Methods with Diferent Methods of Fixations** [17–19]


#### **51.7.5 Champy's System** [21]

Different treatment principles using monocortical miniplates without axial compression for treatment of mandibular and midface fractures were introduced, namely, by Michelet et al. in the late 1960s, which they published in 1973.

Michelet's work has been elaborated by Champy et al. for the management of mandibular angle fracture by the use of intraoral monocortical miniplates. The ideal line of osteosynthesis has been followed by Champy for plates fxation (Fig. 51.9).

It is based on the principle of neutralizing unfavorable traction strains while at the same time allowing transmission of favorable compression forces. The biomechanical validity of Michelet principles was confrmed in a series of multidisciplinary experiments performed in Strasbourg, France, between 1971 and 1974 [21].

#### **Advantages**


With this type of fxation, there is adequate stability to allow direct bony union and is called as functionally stable fxation. There are many fxation techniques used in oral and maxillofacial surgery (OMFS) which are not rigid fxation truly but classifed as functionally stable fxation.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 51.10** Champy's miniplate

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 51.9** Champy's ideal line of osteosynthesis

#### **51.7.5.1 Materials**

Plates and screws are made up of pure titanium. The miniplates are 2 cm long, 0.9 mm thick, and 6 mm wide. They had an elastic limit of fexibility between 70 and 80 per square millimeter, and their rupture point lies between 95 and 110 decanewton (daN) per square millimeter (Fig. 51.10).

#### **51.7.5.2 Miniplates** (Fig. 51.11)


#### **51.7.5.3 Screw**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 51.11** OPG showing fxation with the help of miniplates after Leefort I and bilateral sagittal split osteotomy


The drill has the same diameter as the core of the screws—1.6 mm. This ensures frm anchorage of the selftapping screws.

#### **51.7.5.4 Biomechanical Properties of Screw**  (Fig. 51.12) [22]

– The external or the outer diameter ranges from 0.8 to 2.0 mm. Core diameter of the screw is its internal diameter. The surgical bone screws act by clamping the bone plate and bone together.

**Fig. 51.12** Biomechanical properties of screw


#### **51.7.5.5 Self-Tapping and Drilling Screws**

#### [23, 24, 25]

Self-tapping screw: The screw which is inserted into a predrilled hole without tapping a screw head is the self-tapping screw.

Self-drilling screw has a drilled-shaped point to cut and does not require predrilling. Self-drilling screws have several advantages over the self-tapping such as it does not require drilling the hole and prevents thermal damage leading to infection, screw loosening, osteomyelitis, and nonunion. It also prevents damage to tooth roots and nerves by the use of drills and also avoids the complications associated with drill bit fracture.

#### **51.7.5.6 Monocortical vs. Bicortical Screws**

The monocortical screws are generally used for fxation of mandibular fractures and after sagittal split osteotomy. Chug H-IJ et al. [ 26] also concluded that monocortical screws provide stable fxation. Also chances of damage to the vital structure like inferior alveolar and lingual nerve are less with monocortical screws. Bicortical screws are usually used at the lower border of the mandible for fxation.

#### **51.7.6 Microplates**

The microplate fxation concept was introduced by Luhr in 1988. They are composed of cobalt, vitallium alloy, and molybdenum in the percentage of 68%, 27%, and 5 %, respectively. It has got excellent physical strength and corrosion resistance.

The thickness of plate is 0.5 mm, and the diameter of the screws is 0.8 mm. In all the three dimensions, they can be contoured and maintained an excellent degree of rigidity for osseous segment stabilization. They are used in:


#### **51.7.6.1 Micromesh**

Inspite of its reduced thickness (0.3 mm), micromesh is remarkably strong. It is available in sizes of 40 by 60 and 60 by 100 mm. Template made of a soft, malleable tin alloy comes in various sizes. The template is cut to the shape and size required in the individual case, and then it is contoured to the bone surface. The actual titanium micromesh is then cut out with a wire cutter and contoured on the instrument table reduplicating the individual shape of the template.

#### **51.7.7 AO/ASIF System [27]**

The association of osteosynthesis/association for the study of internal fxation (AO/ASIF) were founded by a group of 15 Swiss surgeons in 1958. The group was led by Maurice E. Muller; AO/ASIF investigators have documented the biologic basis for the concepts on which rigid fxation techniques are based.

Spiessl applied AO/ASIF concepts of long bone healing and modifed AO/ASIF instrumentations for use in mandible in the late 1960s and early 1970s.

Compression can be achieved through static or dynamic means. The two devices that produce static compression are the self-compression plate and lag screw.


The EDCP (eccentric dynamic compression plate) has outer hole which is oblique causing compression on alveolar side and longitudinal inner holes creating basal side interfragmental compression. EDCPs eccentric action eliminates the need for tension band. This plate has most utility for simple fracture of the posterior region where there are no teeth available for splinting.

The reconstruction plate is a load-bearing plate and absorbs the entire functional load. They are designed for use without the tension band. It is large and reinforced version of basal stabilization plate. They can be adapted to local bony contours and are malleable. Depending on the placement of drill hole, it has two-way DC holes that enable compression to be applied in either longitudinal direction.

#### **51.7.7.1 Plates**

	- (a) DCP plates
	- (b) EDCP plates

#### **51.7.7.2 Dynamic Compression Plate (DCP)**

These are designed to withstand tensile loading force in the mandible. In mandibular angle, body, and symphysis regions, they can be used comfortably. It can be applied intraorally or through an extraoral incision. It is used with a tension band. The dynamic compression plate was developed in 1969.

The DCP has a self-compressing hole design. The holes are oblong, and the portion of each hole distant from the fracture has a sloping form or "shoulder."

Experimental work showed that the fat undersurface of the DCP interfered with the vascular supply of the underlying cortex onto which it was compressed by the screws. The concept of "footprint" is the area of undersurface of the plate in contact with the underlying bone cortex.

*Principles of DCP*—The sloping shoulder of the DCP hole has the form of part of an angled cylinder. If a screw is inserted eccentrically, so that its head on fnal tightening slides down the sloping profle of the hole, the screw/bone unit will be shifted toward the fracture, and the fracture plane will thereby be compressed. Such a screw is often referred to as a load screw.

#### **51.7.7.3 Eccentric Dynamic Compression Plate (EDCP)** [27]

It produces a compressive force via arrangement of eccentric and centric (axial) plate holes. EDCP are 8 mm wide and come in four-hole (36 mm long) and six-hole (42 mm long) lengths. The stainless steel plates are 2 mm thick, and the titanium plate is 2.2 mm thick. At the fractures alveolar side, the compression has been provided by the 75° angulation. It is important to place the sloped edge of the angled hole at the mandibular lower border (if the plate is placed upside down, it will tend to distract bone edges at the alveolar border). First central screws are inserted in EDCPs (longitudinal hole eccentrically away from the fracture) than at the lower border; screws are placed in the 75-degree oblique holes eccentrically and in the last rest of the screws inserted in a neutral position. When the plates and tension band splint cannot be used, in those situations EDCP plates are used. The reduction forceps with pressure splinting are useful initially to reduce and compress the fragments when applying the EDCP plate.

#### **51.7.8 Bioresorbable Fixation Systems**

Use of titanium plates and screws is time-tested for their use in management of craniofacial fractures. However, it has many drawbacks including infection, hardware palpation and visibility, hypersensitivity to temperature changes, and stress shielding effect. They also interfere with radiographic examination. Sometimes, metal ions leach out into soft tissues. In view of these complications, bioresorbable implants were developed hoping to reduce hardware-associated complications as well as the necessity for hardware removal.

The use of bioresorbable fxation devices must be limited as their mechanical strength is inferior as compared to the titanium hardware. They can be effectively used in low loadbearing areas of maxillofacial skeleton like maxilla, zygoma, and upper regions of face. The bioresorbable system may not be strong enough to provide adequate stability in mandible fractures which are comminuted, as it is a load-bearing bone. It can be used in simple mandibular fractures.

Bioresorbable fxation systems stabilize fracture segments long enough for fracture healing and union to occur then dissolve, thereby reducing complications frequently encountered with metallic hardware such as palpability, visibility, cold sensitivity, and need for removal. Most commonly polylactic acid (PLA) is used in bioresorbable plates.

#### **Complications** [28]


#### **51.8 Recent Developments**

To reduce the stress shielding, reduction in modulus is the answer to correct the disadvantages of internal fxation. To improve the healing of the fracture under the plates, the only solution is to allow micromotion through the fracture site; the design should be made in such a way that it resists torsional, bending, and shear movements.

#### **51.8.1 Three-Dimensional (3D) Plates**

(Fig. 51.13)

The two miniplates are connected by interconnecting crossbars which are used as 3D plates. Technically, they are not three-dimensional structures, but their closed quadrilateral shape provides stability in all three dimensions.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 51.13** Orthopantomogram showing fxation with threedimensional plate

#### **51.8.2 Virtual Surgical Planning, Computer-Assisted Design, and 3D Modelling**

The management of the facial fracture is very challenging due to its unique three-dimensional contours and nonlinearity of facial skeleton. The recent development in the software technology and 3D modeling has revolutionized the treatment. They can be used as an adjunct to the standard preoperative preparation.

To reduce the operating time in the operation theater, the 3D models can serve as a template on which pre contouring of the fxation plates can be done. Custom-designed titanium implants can be made with the help of 3D printers to get the accurate ft. They can be preferred over the conventional implants and reduce the surgical time. The model design and virtual surgical planning help in constructing the guides which can be used perioperatively, can design the optimal approach preoperatively, and can compare the actual outcome to the virtual design. To reconstruct the multitude of craniomaxillofacial defects of mandible, zygoma, midface, and orbit, these technologies are very helpful. 3D modeling and computer-assisted surgical planning have been very helpful in managing the complications associated with these injuries.

#### **51.8.3 Intraoperative Imaging** [29]

Intraoperative imaging is very important in assessing the reduction and fxation of all maxillofacial fractures, and according to its feedback, the surgeons can immediately make corrections of any error that occur during reduction and fxation, which indirectly reduces the complications and avoids potential resurgeries. Computed tomography (CT) is commonly used for the same purpose.

#### **51.9 Conclusion**

For the treatment of maxillofacial fractures, many fxation methods have been used with great success. To reestablish the pre-injury esthetics, the normal masticatory function and the proper occlusion in cases of such fractures are the main objectives of the treatment. Maxillomandibular fxation can be done for the conservative management of such fractures which can be carried out with the help of arch bars, wiring, and cap splints and in edentulous patients by gunning splints. The open reduction and internal fxation can be carried out with the help of miniplates, microplates, 3D plates, and reconstruction plates. Different plating systems and wiring techniques make the management of these maxillofacial fractures predictable with high success rate.

**Acknowledgment** Author wishes to thank Dr. Anshul Rai for providing Figs. 51.6, 51.7, 51.11, and 51.13.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Fractures of the Mandible**

### Anshul Rai

#### **52.1 Defnition**

A fracture is defned as "A breach in the continuity of bone."

#### **52.2 Introduction**

The mandible which is the only mobile bone of the maxillofacial region forms the lower third of the face. Owing to the prominence of the symphysis of the mandible, it is most vulnerable site to be traumatized during the road traffc accidents and, at the same time, most tempting site to be hit during the assault. Thus, the fractures of the mandible are one of the most common in maxillofacial area. It also affects the social life of the patients (Box 52.1).

The word "mandible" derives from the Latin word mandere "to chew" and -bula (instrument) which literally translates to mandibulaie "instrument used for chewing."

The bone is formed in the fetus from a fusion of the left and right mandibular prominences and the point where these sides join, the mandibular symphysis. Like other symphysis in the body, this is a midline articulation where the bones are joined by fbrocartilage, but this articulation fuses together in early childhood.

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_52) contains supplementary material, which is available to authorized users.

#### **Box 52.1: General Efect of Mandible Fracture on Social Life [1]**


#### **52.3 Surgical Anatomy**

The mandible is a horseshoe-shaped only mobile bone of the facial skeleton. It is the strongest bone with thick cortices. Symphysis is the most prominent part of mandible, and the condyles articulate with glenoid fossa of temporal bone. The inferior alveolar neurovascular bundle passes through the bone, and in the case of fracture, it may get traumatized and can lead to hematoma and neurological defcit.

#### **52.3.1 Angle of the Mandible**

By defnition, there are three types of angle as described below:


**52**

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1053

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_52

A. Rai (\*)

Department of Dentistry, All India Institute of Medical Sciences, Bhopal, Madhya Pradesh, India e-mail: anshul.dentalsurgery@aiimsbhopal.edu.in

Anatomically, mandibular angle is a weaker structure compared to other anatomic subsites.


#### **52.3.2 Canine Region of the Mandible**

In the canine area, also the mandible is weaker as the canine has the longest and the strongest root, and it occupies lot of space in the bone and undermines and weakens it. Thus, the mandible has a tendency to fracture at this site.

#### **52.3.3 Symphysis and Parasymphysis of Mandible**


#### **52.4 Classifcation**

The general classifcation of fractures of bone is described in Table 52.1.



#### **52.4.1 Classifcation of Mandibular Fracture According to Site** (Fig. 52.1)

Figure 52.1 highlights the mandibular fracture according to site of fracture with its incidence [2].

#### **52.4.2 Classifcation of Mandibular Fracture According to the Impact**

According to the impact on bone, fracture can be classifed as direct fracture and indirect fracture.

During an impact, the force on the cortex results in compression, and the other cortex undergoes tension. If the force of the impact is more than the compressive and tensile strength of the bone, the bone fractures.

In a similar fashion, when there is an impact, the point of application of force gets compressed, and the resultant vector travels along the bone and applies tensor force on the point intersected by this vector. The fracture at the site of impact is called **direct fracture**, and the fracture at the site of intersection with the vector is **indirect fracture**.

For instance, the force applied to the symphysis menti results in a direct fracture at the symphysis. The vector travels to the condylar necks bilaterally and induce indirect fractures

**Fig. 52.1** (**a**, **b**) Highlights the mandibular fracture according to site of fracture with its incidence

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**Fig. 52.2** 3D CT showing parasymphysis and bilateral condyle fracture

**Table 52.2** Combination of mandibular fractures


of subcondylar areas bilaterally, as the condylar necks are weak. This is called a "tripod fracture" (as the fracture is at 3 points) or "parade ground fracture" or "guardsman's fracture." The later terms are used because these fractures are commonly seen among soldiers who stand upright on the parade ground for a long time. When they faint, they fall on their chin resulting in symphysis and bilateral condylar neck fractures.

### **52.4.3 Combination of Fracture**

The most common mandible fracture seen in the developed countries is angle fracture combined with contralateral body or symphysis of the mandible [3]. Table 52.2 and Figs. 52.2, 52.3, and 52.4 highlight various combinations of direct and indirect fractures in the mandible.

### **52.4.4 Classifcation of Mandibular Fracture According to Displacement**

The fracture fragments are liable to displacement according to unfavorable muscle pull leading to diffculty in the management of these displaced fractures. Table 52.3 highlights various muscles attached to the mandible with their actions.

According to the displacement of fracture fragments due to muscle pull, the fracture can be classifed as:

When viewed from superior aspect:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.3** Showing right parasymphysis and left condyle fracture

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.4** Showing right body and left angle fracture

lingually due to the pull of the medial pterygoid muscle; thus there will be separation of the fragments in the buccolingual plane due to the unfavorable muscle pull, and the fracture is said to be vertically unfavorable (Fig. 52.5b).

When viewed from buccal aspect:


**Table 52.3** Muscle attachments over the mandible with their actions


#### **52.5 Clinical Features**

The clinical features of the fractures are described in Table 52.4 (Figs. 52.7, 52.8, 52.9, 52.10, 52.11, 52.12, 52.13, and 52.14).

#### **52.6 Clinical Examination**

#### **52.6.1 Bimanual Palpation**

The abnormal mobility at the fracture site can be elicited by the bimanual palpation. The mandible is grasped on either side of the suspected fracture line in such a way that the index fnger is on the occlusal surface of the teeth and the thumbs are on the inferior border. The proximal and distal segments are moved in supero-inferior and anteroposterior direction, to elicit abnormal mobility (Fig. 52.15).

#### **52.6.2 Compression Test**

When there is a hairline, undisplaced fracture of the mandible especially at the symphysis or angle or in the subcondylar areas and it is not conspicuous clinically and radiologically, a compression of the mandible at the symphysis area and both the sides over the body, using both the palms by the operator, elicits tenderness which may suggest the fracture (Fig. 52.16a, b).

#### **52.7 Radiographic Examination**

As a rule, in orthopedics, the X-ray must be taken in two planes perpendicular to each other, i.e., in the anteroposterior and mediolateral. The most common radiographs to detect fracture of the mandible are:


**Fig. 52.5** (**a**) Vertically favorable. (**b**) Vertically unfavorable

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.6** (**a**) Horizontally favorable. (**b**) Horizontally unfavorable



©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.7** Swelling in angle region after fracture

#### **52.7.1 Are Postoperative Radiographs Necessary?**

The answer is no. The reasons behind this is:


However, the postoperative radiographs are required in few cases of:

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.8** Diffculty in mouth opening due to displacement and deviation of fracture


Bergh van den et al. [6] also suggested that postoperative radiography is not necessary. The advantages of avoiding postoperative radiographs are:


#### 52 Fractures of the Mandible

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.9** Hematoma in the angle region

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.11** Discoloration of skin

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**Fig. 52.10** Presence of abrasion, contusion, or laceration

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**Fig. 52.12** Visible step deformity in cases with displacement of fractured segments

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1060

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**Fig. 52.13** Malocclusion

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**Fig. 52.15** Bimanual palpation

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**Fig. 52.14** Sublingual hematoma (Coleman's sign)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.16** (**a**, **b**) Vertical and horizontal compression test

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.17** OPG demonstrating parasymphysis and contralateral condylar fracture

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.18** PA view mandible showing left mandibular angle fracture

**Fig. 52.19** Computed tomography (CT) scan demonstrating displaced left para median fracture

> Once the basic Airway, breathing, circulation (ABC) in the emergency management has been secured, the suturing of the extra-/intraoral wounds and initial stabilization and immobilization of the fracture fragments are important. Box 52.2 shows

**52.8 Emergency Management (refer Chap.** 

**Fig. 52.21** Cone beam computed tomography (CBCT) demonstrating

**48 of this book)**

displaced right para median fracture mandible

advantages of immobilization of fracture fragments.

Initial stabilization and immobilization is done by:

#### 1. **Bridle wiring (refer Chap. 50 of this book)**

It is a type of temporary stabilization and reduction of the fracture fragments of the dentate segment with the help of 24- or 26-gauge wires under local anesthesia.

The wire should be wrapped around two healthy teeth adjacent to the fracture line; if the tooth adjacent to the fracture are mobile, the wire should be wrapped around the second tooth adjacent to the fracture (Fig. 52.22a, b).

#### 2. **Supportive bandage**

These bandages are commonly used to temporarily stabilize the fracture of the lower jaw. Small crepe bandages can be used for mandible fracture.


**Fig. 52.20** Digital visual tomography (DVT) demonstrating comminuted right body fracture

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.22** (**a**, **b**) Temporary stabilization of a grossly displaced bilateral body fracture by bridle wiring

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.23** Barrel bandage

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.24** Four-tailed bandage

### **52.9 Goals of Treatment of Mandibular Fracture** (Table 52.5)

#### **52.10 Treatment Options for Diferent Sites**

**52.10.1 Closed Reduction** (Table 52.6)

#### **52.10.2 Clinical Tip**

Wiring techniques required use of multiple wires. These wires cause inadvertent fnger puncture to the operator's fngers and increases the risk of spread of blood-borne diseases like HIV and hepatitis. To avoid such complication, Rai [7] recommended the use of dynaplast adhesive tape over all fngertips before wearing sterile gloves while doing Maxillomandibular Fixation (MMF) (Fig. 52.25).

#### **52.10.3 Open Reduction** (Table 52.7)

#### **52.10.4 Steps in Open Reduction Internal Fixation (ORIF) of Mandible Fracture**

1. Incision (extra-/intraoral) (Fig. 52.26a, b).







©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.25** Finger protection before wiring


According to Dimitroulis [8] MMF is unnecessary in undisplaced angle fracture if there is a skilled assistant present to assist and help manually reduce the fracture fragments for plating. Author also believes that many undisplaced, single fracture of mandible can be fxed without MMF when two skilled surgeons operate the case.

#### **52.10.5 Symphysis and Parasymphysis Fracture** (Video 52.1)

Various internal fxation techniques were mentioned in the literature for both symphysis and parasymphysis fractures [9]. They are enumerated in Table 52.8.

Note: Readers has to refer Chap. 51 on plating systems to know the principles of osteosynthesis, tension banding, zone of compression/tension, etc.

Fixation with two miniplates is widely used for the fxation of symphysis and parasymphysis fractures (Fig. 52.31). Some authors preferred use of two lag screws (Fig. 52.32a, b) for the fxation of symphysis fractures, but their uses are less in comparison to two miniplates because they are technique sensitive. Three-dimensional plates require less manipulation and adaptation which indirectly reduce the operating time

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.26** (**a**, **b**) Extraoral sub mandibular incision and intraoral vestibular incision

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**Fig. 52.27** Exposure of the fracture site (left paramedian mandible via vestibular incision)

(Fig. 52.33), but use of it is questionable when fracture fragments are multiple even in isolated symphysis fractures.

Usually, an intraoral approach is preferred for management of symphysis and parasymphysis fractures. However, if an existing laceration or scar is present, it should be utilized for exposure of fractured segments and subsequent management (Fig. 52.34).

#### **52.10.6 Parasymphysis Fracture**


3. One miniplate above and another below the mental nerve used for fxation of parasymphysis fracture (Fig. 52.35).

### **52.10.7 Mandibular Angle**

The prevalence of angle fractures ranges from 16.5 to 37 % in the literature. Presence of third molar (3M) increases the chance of angle fracture by 3.27 times, and class II-B positions of 3M are the most favorable for angle fracture, while class I-A act as protective factors [10].

### **52.10.7.1 Impact of Presence or Absence of Impacted Mandibular Third Molar (IM3M) on Angle and Condylar Fracture**


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**Fig. 52.28** (**a**–**c**) Reduction of the fracture (with the help of bone holding forceps)

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**Fig. 52.29** (**a**, **b**) Use of chin retractor in reduction of fracture fragments

#### **52.10.7.2 Open vs. Closed Reduction**

Closed reduction is advisable for patients who are medically unft for surgery (due to any reasons) or those who did not give consent for open reduction internal fxation (ORIF).

#### **52.10.7.3 Approaches for ORIF**


Intraoral incision is advocated for ORIF with single miniplate, but higher infection rate of 13% was reported in comparison with 2% when extraoral incision was used for plating. Marginal mandibular nerve showed weakness in 8% of cases, and it sometimes has prominent extraoral scarring in patients treated with extraoral approach [14] .

Sugar [15] concluded that the combined use of transbuccal and intraoral approach is safe and effective than the intraoral approach alone for ORIF. Author too prefers the same approach.

#### **52.10.7.4 Advantages of Transbuccal Approach** [16]


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.30** Application of pressure bandage

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.31** Fixation bilateral paramedian fracture mandible with 2 miniplates each on either side

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.32** (**a**, **b**) Fixation left para median fracture mandible with lag screws

#### **Position of Trocar Placement** [17] (Fig. 52.37)

Gulses et al. described a safe zone to place the trocar in the form of a triangle created by drawing three lines on the face.

Line 1: At the lower border of mandible (mandibular line)


**Table 52.8** Various fxation techniques for anterior mandibular fracture


Through a small stab incision, a blunt dissection is performed with dissecting scissors till the mandibular periosteum is torn and the trocar is placed through the dissected channel.

1068

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.33** Fixation of anterior mandible with three-dimensional plate

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.35** One miniplate above and another below the mental nerve used for fxation of parasymphysis fracture

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.34** (**a**–**c**) Existing laceration has been used as access for fxation of the anterior mandible fracture

Various techniques are mentioned in the literature for internal fxation of angle fracture (Box 52.3) [18]:

#### **52.10.7.5 Single vs. Two Plates vs. 3D Plates**

**Al Moraissi** [19] in a meta-analysis showed that the incidence of wound infection, dehiscence, hardware failure, and overall complications were less in patients treated with one miniplate on external oblique ridge in comparison to two.

**Ellis III** [20] also advocated use of single miniplate on superior border because:

#### **Box 52.3: Fixation Techniques for Angle Fracture**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.36** Intraoral incision for exposure

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.37** Transbuccal approach used for fxation of angle fractures


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.38** Fixation of mandibular angle fracture using single miniplate

– If infection occurs, retrieval of single miniplate can be done under local anesthesia in a clinic, but two plates commonly required general anesthesia which indirectly increases the cost and prolonged the hospital stay.

**Rai et al.** [21] also conclude better results with two-plate fxation. Second miniplate is supposed to increase stability and protects the fracture site against torsion and bending. 1070

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.39** Fixation of mandibular angle fracture using two miniplates. (**a**) Clinical picture, (**b**) orthopantamogram

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.40** Fixation of mandibular angle fracture using 3D plate. (**a**) Clinical picture, (**b**) orthopantamogram

Theoretically second plate establishes a second line of osteosynthesis.

**Levy et al.** [22]advocated two-plate fxation superior for ORIF of angle fracture. According to them two miniplates provide better stabilization and have reported lowest complication rate in comparison to any other plating technique.

**Wusiman et al.** [23] demonstrate that three-dimensional (3D) miniplates provide better fxation than standard miniplates. It also provides simultaneous stabilization of tension and compression zones with lower incidence of postoperative complications and good results. According to Zix et al. [24] 1-mm-thick 3D plate is as stable as 2 mm miniplates, and it offers better bending stability and more resistant to out of plane movement or torque.

**Ellis III and Ghali** [25] used lag screws for treating mandibular angle fractures but reported very high incidence of postoperative infection and bone exposure. Also the fxation of angle with lag screws is technique sensitive and requires expertise.

**Kang and Zide** used seven-hole angle plate when Champy technique is ineffective and more rigid or semirigid fxation is required [26]. According to them seven-hole angle plate is fxed through transfacial trocar and stabilized intraorally. On the other hand, Champy plate required bending, lacks rigidity, diffculty in screw hole drilling, inaccurate centric placement of screws.

#### **52.10.7.6 Extraction vs. Retention of IM3M in Angle Fracture**

The use of postoperative MMF and extraction versus retention of teeth in the line of fracture did not infuence any of the outcomes [27]. Increase rate of infection by extraction of a tooth was found in the study by Ellis and Walker in 1994 [28]. However, in another study published in 2002, Ellis [29] reported an increased incidence of infection if teeth were left in the line of fracture. Author advocates extraction of 3Ms at the time of ORIF for better results.

#### **52.10.8 Body Fracture**

A single four hole with gap miniplate (Fig. 52.41) below the root apex and the inferior alveolar canal is suffcient for fxation of body fracture of mandible through the intraoral approach most of the times, except when a patient is having

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.41** Fixation of body fracture with single miniplate

extraoral soft tissue injury/scar or having severely comminuted fracture fragments.

#### **52.10.9 Ramus Fracture**

Mandibular ramus (MR) fracture occurs rarely and ranked third least common fracture after alveolar and coronoid fracture [30]. MR fractures are very rare in isolation. It can be horizontal or vertical. Its incidence ranges from 0.9 to 5.5% [31]. Isolated ramus fracture can be managed by closed reduction, but ORIF is the treatment of choice when it is associated with other maxillofacial fractures. To correct the facial height when midface is also fractured, the vertical rami become the only determinant, and re-establishment of these buttresses is very important before repositioning the crushed midfacial bones [32] (Fig. 52.42a–c).

#### **52.10.9.1 Management of Triangular Fragments (TF) at the Lower Border**

Heslop et al. [33] advocated repositioning of TF if they are attached to the muscle or periosteum and remove them if they are very small or detached from the periosteum.

According to Blinder et al. [34] to prevent infection and preserve vascularization, TF should be unexposed and unreduced. TF should be sandwiched between the two fracture lines by rigid fxation without exposure, and preserving vascularization may be the treatment of choice

TF of bone at the angle region were more often shown to get infected in comparison to body, symphysis, or parasymphysis because thick, better vascularized, and more cancellous bone presents in these areas as compared to angle region. It's better to remove small fragments in the angle region to avoid postoperative discomfort.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.42** Management of mandibular ramus fracture. (**a**) DVT showing mandibular ramus fracture, (**b**) fxation using two miniplates, (**c**) postoperative orthopantamogram showing fxation of mandibular ramus and midface fractures (blue arrows point to lower border plates and green arrows point to upper border plates)

#### **52.10.10 Coronoid Fracture**

It generally occurs in combination with other fracture of the mandible (Fig. 52.43a), and with zygomatic complex fracture (commonly with arch) (Fig. 52.43b), rarely does it occur in isolation. It can be treated by extraoral or intraoral approaches. Later, having low incidence of facial nerve injury and no facial scar. Coronoid fracture ranges from 0.6 to 4.7% of all facial fractures and 1–2.9% of all mandibular fractures [35].

It manifests as [36, 37]:


#### **52.10.10.1 Indications for Conservative or Open Reduction of Coronoid Fractures**  (Table 52.9)

Conservative management in the form of soft diet and mouth opening exercises to avoid bony adhesions to the surrounding structures [38]. If patients are treated with MMF and trismus occurs, it can be managed by removal of the coronoid process [39].

#### **52.10.11 Bilateral Fracture of Mandible**

Over half of the mandibular fractures are bilateral; in the case of angle fracture, most of the times, it occurs in combination of contralateral mandibular body and symphysis [40]. ORIF is the treatment of choice most of the times.

Clinical Tip: An MMF screw can be effectively used for reduction of a bilateral mandibular fracture by placing the screw in the symphysis region. A wire is passed through the screw, and the fracture segment can be manipulated for reduction (Fig. 52.44).

**Table 52.9** Indications of closed and open reduction for coronoid fractures


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.43** Coronoid fracture (**a**) associated with condylar fracture, (**b**) associated with zygomatic arch

#### **52.10.12 Comminuted Mandible Fractures**

Comminution is defned as presence of multiple fracture lines in many small pieces within the same area of mandibular angle, body, ramus, and symphysis [41]. This type of fracture rarely occurs in the condyle region. In a comminuted fracture, bone is "crushed, broken, splintered" into number of pieces, creating multiple small fragments (at least two free segments of bone) (Fig. 52.45a, b).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.44** Use of MMF screw in reduction of bilateral parasymphysis fracture

To fx small fragments, multiple options are mentioned in the literature like miniplate, microplate, screws, steel wires, and absorbable sutures. A fragment larger than 1 cm should be conserved, reduced, and fxed [42].

Ellis et al. [43] advocated that more complications are associated with multiple fragment fractures in comparison to fractures having few segments. Therefore, comminuted fractures need load-bearing fxation.

The bone fragments will not provide buttressing to help stabilize the fracture; therefore surgeons operating comminuted mandibular fractures having two or more free bone fragments and/or requiring bone fragment removal should opt for reconstruction plates. Miniplates can be used when comminuted mandibular fractures have only one free bone fragment. Combination of reconstruction and miniplates can be used when multiple small fragments are there in comminuted mandible fracture (Fig. 52.46). Implants used for fxation of comminuted fractures are mentioned in Box 52.4.

Use of reconstruction plates required expertise and it is time-consuming. Sometimes contour is also not favorable

#### **Box 52.4: Implants Used for Fixation of Comminuted Fractures**


©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.46** Combination of reconstruction and miniplates in management of comminuted fractures

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.47** Postoperative elastics for correction of minor occlusal discrepancies (Inter maxillary elastics- IME)

which can create slight malocclusion but can be managed by postoperative elastics and selective occlusal adjustments (Fig. 52.47).

Dia et al. [44] used titanium mesh for the treatment of comminuted mandible fracture with successful results. According to them mesh required little soft tissue exposure, had low infection rate, and provides favorable mandibular morphology.

#### **52.11 Inferior Alveolar Nerve (IAN) Injury in Mandible Fracture**

According to the literature, the incidence of IAN injury was [45]:


The neurosensory testing was done both before and after the treatment of mandibular fracture in which nerve injury is suspected. Two-point discrimination and pinprick testing can be used to assess the level of IAN injury. Preoperative knowledge of the patient's IAN position (based on CT/CBCT) is very important in decision-making regarding fxation position of the fracture fragments with miniplates. Plating should be done above or below the course of IAN. ORIF in the area of IAN takes longer duration to normalization of sensation, and it ranges from 1 week to 12 months. Postoperative CT/CBCT is mandatory if operating surgeon suspected the impingement of screw on the IAN or no relief of sensation after 6 weeks of ORIF for further management. Surgeons should not hesitate to redo the surgery in cases of IAN injury by miniplates and screws.

#### **52.12 Geriatric Mandibular Fracture**

With old age, the incidence rate of maxillofacial fracture increases, with mandibular fracture appearing with a greater frequency. As the age advances, the weakening of the mandible occurs due to:


The most common mechanisms of injury in geriatric patients are [46]:


Fractures of the edentulous mandible pose unique challenges. Old age itself is a risk factor for poor outcomes following trauma. There are associated comorbidities like hypertension, diabetes mellitus, dementia, or stroke which limit the functional capacity of the patient to bear the stress of surgery and postoperative recovery. Also, the atrophic mandible has compromised blood supply with little osteogenic potential resulting in delayed bone healing. Bilateral mandibular fracture (bucket handle fracture) occurs most commonly in elderly (Fig. 52.48).

#### **52.12.1 Management**

Controversy exists in the treatment of edentulous mandibular fracture. One school of thought advocated closed reduction, and another school is in favor of open reduction and internal fxation. According to Bradley [47] the major blood supply to the mandible is "sub periosteal Plexus," and refection of periosteum in ORIF may seriously impair vascular supply to the bone resulting in non-union.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.48** Bilateral mandibular fracture (bucket handle fracture) in edentulous patients

Controversy again exists in the use of bone grafts in edentulous mandible. Are bone grafts necessary? Answer is not always. Reconstruction plates (load-bearing plates) can be used for comminuted fractures and with large defects. Bone morphogenic proteins and tricalcium phosphate can be used as alternative to autogenous grafts in patients whom multiple comorbidities may infuence local or systemic outcomes [48].

Few authors advocated extramucosal intraoral plating for the ORIF of the edentulous mandibular fracture. It preserves the blood supply to the mucosa and bone, at the same time provides adequate stability [49, 50].

The techniques of edentulous atrophic mandible fracture management are:

#### 1. Closed reduction (CR)

This technique is opted when the patient's systemic condition does not allow for an open surgery. CR can be accomplished if the mandibular height is at least 30 mm. It is diffcult to achieve CR if the mandibular height is <10 mm. CR can be accomplished using a preexisting denture. If there is no denture, gunning splint can be prepared. The denture/splint is used for immobilization and fxed to the mandible with circum-mandibular wiring (Fig. 52.49a, b).

Advantages: Periosteal supply to the bone is maintained.

Disadvantages: Chances of infection and pulmonary issues

2. Open reduction and internal fxation (ORIF)

This involves use of plates and screws for fxation of fractures. Options for ORIF include use of miniplates or larger reconstruction plates. Miniplates are small and

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.49** (**a**) Securing gunning splint by circum-mandibular wiring, (**b**) MMF with gunning splint in situ

hence require smaller incision. Screws of miniplates are also small which can easily involve thin fragments. However, in cases of larger fractures, a load-bearing reconstruction plate is preferred.

Advantages: Adequate fxation with no/minimum MMF

Disadvantages: Delayed healing with periosteal blood supply loss

#### **52.13 Pediatric Mandibular Fractures**

Among all the maxillofacial fractures, the incidence of pediatric facial fracture is 1–15%. After nasal bone fracture, the second most common fractures in children are mandibular fracture with an incidence of 5–50% [51]. In mandible, the condyle is the commonest site of fracture in pediatric patients followed by symphysis and parasymphysis. The most common mechanisms of injury in children are [52]:


In children, the developing tooth buds of canine approximate the lower border of mandible. This creates a stress point making the mandible susceptible to fracture in this location. Once the canine erupts, this weak point is reinforced with the bone and is not weaker than any other regions of the mandible. This is the reason probably why parasymphysis fracture is more common in children than adolescents.

With increasing age, the skull-to-face ratio decreases. The larger cranium shields the smaller middle and lower thirds of the face from injuries. This prevents mandibular fracture in small children; however, with increasing age the mandible becomes more prominent resulting in more injuries to this region.

#### **52.13.1 Management**

The management of pediatric mandibular fractures is different in comparison to adults due to [53]:


Pediatric mandibular fractures are treated in the following ways:


However the absence of teeth due to exfoliation and poor retention of wires on the deciduous teeth crowns makes the ligature wire and traditional use of arch bars diffcult or sometimes impossible [54]. In such cases splinting with acrylic splint retained with circum-mandibular wires remains a viable option in treatment of pediatric mandibular fractures.

Cap splints are secured to mandible by circum-mandibular wiring. Kelsey Fry bone awl is used for this purpose. A widebore needle can also be used for the same (Fig. 52.51a, b). Intravenous cannula stillete (IVCS) is also mentioned in the literature for performing circum-mandibular wiring. The 16-gauge IVCS was used instead of conventional awl [55].

However, management of pediatric mandibular fracture with ORIF is controversial as the fxation of plates may hamper the growth and development of jaw. Titanium miniplates have been successfully used for ORIF, but the implants are to be removed within 3- to 12-month period [56].

Yerit et al. [57] proposed use of biodegradable plates for ORIF. These plates should be mechanically strong and must undergo resorption within a predictable time frame.

The advantages of biodegradable plates (polyglycolic and poly-L-lactic acid plating system) in comparison to titanium plates are [58]:


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**Fig. 52.50** (**a**) Pediatric mandibular fracture, (**b**) cap splint secured using circum-mandibular wiring, (**c**) postoperative orthopantamogram

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.51** (**a**, **b**) Securing cap splint by circum-mandibular wiring using wide-bore needle

#### **52.14 Use of Bone Grafts in Mandible Fracture Treatment**

Anterior iliac crest (cancellous or cortico-cancellous) and fbula (free microvascular reconstruction) are the most commonly used sites from where the bone grafts are used for mandibular reconstruction. All the cases required bone grafting in cases of mandibular fracture treated with ORIF should be kept in MMF of 4 weeks postoperatively.

Bone grafts are indicated in some cases of:


Rachmiel et al. [59] advocated two-stage reconstruction of mandibular bone defect after trauma by bone grafting followed by alveolar distraction osteogenesis (ADO). This modality helps in correction of intermaxillary vertical relationship and provides suffcient amount of bone for the placement of dental implants and prosthesis.

### **52.15 Postoperative Care**


1078


#### **52.16 Complications of Mandible Fracture**

#### **Immediate**


#### **Delayed**

• **Infection:** Found to be the most common complication (Fig. 52.52)

	- 1. Preoperative oral sepsis
	- 2. Tooth in the line of fracture
	- 3. Improper reduction and fxation (Fig. 52.53)
	- 4. Alcoholic or metabolic disturbances
	- 5. Prolonged time before treatment
	- 6. Poor patient compliance
	- It indicates that a fracture has healed but in less than an optimal position.
	- It may result when bone is shorter than normal, rotated or twisted in a bad position, or bent.
	- It may cause pain, joint degeneration, posttraumatic arthritis, or catching episodes resulting from instability.
	- It is a type of uncommon complication of mandibular fracture, with reported incidence of 2.8–3.9% [60].
	- It is failure of fracture hematoma to become transformed into an osteogenic matrix so that it is converted into non-osteogenic fbrous tissue.
	- Non-union identifed by mobility in all planes after interval of minimum 10 weeks.
	- Histologically there is absence of identifable osteogenic tissue.
	- Radiographically no evidence of progressive decrease in radiolucency at the fracture site and rounding off of the bones' end in the later stages. It can be treated by ORIF by rigid fxation (load-bearing reconstruction plate and sometimes in combination with bone graft) (Fig. 52.54a, b).

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.53** Postoperative infection due to improper reduction and fxation

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.54** (**a**) Non-union due to closed reduction, (**b**) management of fracture non-union by load-bearing reconstruction plate



©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.55** Showing malocclusion

### **52.16.1 Management of Mandibular Non-union Depending upon the Size of the Defect** (Table 52.10) [61]


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.56** Facial asymmetry


### **52.17 Recent Advances**

Kokosis et al. [62] advocated use of virtual surgical planning (VSP) with subsequent computer-aided design and manufacturing in management of acute mandibular trauma patients.

The advantages of the use of custom titanium plate in mandibular trauma are:


Computer-assisted surgery (CAS) including computer-aided design and manufacturing, surgical navigation techniques, and rapid prototyping (RP) has been used with lot of success in mandibular reconstruction (refer Chap. 41 of this book). CAS helps in [63]:


#### **Some Important Facts from Review of Literature Regarding Mandible Fracture [64, 65]**


#### **52.18 Case Scenarios**

#### **Case Scenario 1**

A male patient reported with a gunshot injury over right side of face. Patient's Glassgow coma scale (GCS) was 15/15 with stable vital signs, but the patient has diffculty in breathing. On maxillofacial examination, a gunshot wound was present over right side of face at the right mandibular angle region. Deviation of mandible was present on right side with cross bite on right side and open bite on left side. Tenderness was present over right mandibular angle region. On palpation, intersegmental mobility was present over right angle region.

Provisional diagnosis: Right mandibular angle fracture following gunshot

Investigation: Apart from blood investigation, a CT scan was performed, and a fnal diagnosis of comminuted right mandibular ramus and angle fracture with bullet in situ was made (Fig. 52.57a).

Management: Patient was subjected to emergency surgery under general anesthesia with a treatment plan of bullet retrieval, debridement, and open reduction and internal fxation of fracture. After the anesthesia was induced, patient preparation was done; the fracture site was exposed through an extraoral approach. Thorough debridement was done, and bullet was retrieved in multiple pieces (Fig. 52.57b). The bone segments which were detached were removed, and the fracture segments were fxed using a reconstruction plate following achieving occlusion (Fig. 52.57c). The use of bone graft was eliminated considering the risk of postoperative infection due to scattering of bullet particles. Moreover, the fracture site was a nondentate site; hence bone grafting was not mandatorily indicated for postoperative dental rehabilitation. Figure 52.57d shows postoperative OPG and fxation of fracture with reconstruction plate (refer Chap. 59 on Gun shot injuries).

#### **Case Scenario 2**

A female patient reported with the chief complaint of diffculty in chewing following operation to treat mandibular fracture. Patient gave a history of fall from height following which she was operated for ORIF elsewhere. The general condition of patient was good. On maxillofacial examination, mandible was deviated on right side with cross bite on right

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.57** Case Scenario 1 (**a**) DVT showing comminuted right mandibular angle and ramus fracture with bullet in situ; (**b**) retrieved bullet; (**c**) bullet retrieval, debridement, and fxation of fracture with recon-

struction plate; (**d**) postoperative OPG showing fxation of fracture with reconstruction plate

side and open bite with lingualized occlusion on left side (Fig. 52.58a). Patient provided us with a pretreatment OPG which revealed right subcondylar with left side mandibular comminuted body and angle fracture (Fig. 52.58b). We subjected the patient to another OPG which revealed improper fxation of left mandibular body fracture and no fxation of left angle and right subcondylar fracture (Fig. 52.58c).

Diagnosis: Malunited left mandibular body, left angle fracture, and right subcondylar fracture

Management: Patient was subjected to general anesthesia. Once the anesthesia was induced, patient preparation was done, and fracture site was exposed through extraoral incision for all the fractures. Existing implants were removed which resulted in removal of few small bone fragments. The fractured and carious teeth were extracted and reduction was done by MMF. Occlusion was achieved (Fig. 52.58d), and fxation was performed using two miniplates at subcondylar site and load-bearing reconstruction plate at the body-angle unit. A postoperative OPG was done (Fig. 52.58e). Patient was discharged in stable condition. After 6 months, dental rehabilitation was performed for missing teeth by delivering dental bridge (Fig. 52.58f).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 52.58** Case scenario 2 (**a**) Deranged occlusion when patient reported to us, (**b**) pretreatment OPG, (**c**) improper fxation of left mandibular body fracture and no fxation of left angle and right subcondylar fracture at other centre, (**d**) intraoperative occlusion achieved, (**e**) postoperative OPG, (**f**) postoperative accurate occlusion

#### **References**


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## **Fracture of the Mandibular Condyle**

Vikas Dhupar

### **53.1 Introduction**

Maxillofacial surgeons commonly come across a high incidence of condylar fractures in their practice. A French surgeon [1] in the eighteenth century described a high propensity for a narrow portion in the subcondylar region to fracture, which is a common occurrence even today. In spite of a common occurrence, the management has been controversial as there is no established consensus in the treatment of condylar fractures. Traditionally closed reduction has been the treatment of choice for condylar fractures and have been treated by various forms of intermaxillary fxation. With the improvement in radiographic imaging and biomaterials used in the fxation, surgical management has gradually found acceptance as it restores early function.

### **53.2 Surgical Anatomy**

The mandibular condyle forms a part of the temporomandibular joint which is unique (Box 53.1), and it is made of the following structures:


V. Dhupar (\*)

#### **Box 53.1. TMJ—Unique Characteristics**


#### **53.2.1 Condyle**

The condyle is one of the two processes of the mandible present on the superior portion of the ramus. The condylar head is ovoid in shape measuring approximately 15–20 mm mediolaterally and 8–10 mm anteroposteriorly in dimension [2]. The mandibular condyle articulates with the glenoid fossa present in the squamous portion of the temporal bone to form the temporomandibular joint (Fig. 53.1). Squamous portion of the temporal bone is as thin as 2 mm as a result; the condylar processes maybe driven into the middle cranial fossa following trauma.

#### **53.2.2 Articular Disc**

The squamous portion of the temporal bone and the condyle is separated by a dense fbrous connective tissue called the articular disc. The disc is frmly anchored to the condyle by the medial and lateral collateral ligaments, and it merges with the capsule in the periphery. The joint space is divided into superior and inferior compartments by the disc.

#### **53.2.3 Capsule and Ligaments**

The capsule surrounds the TMJ and is reinforced by the medial and lateral ligaments which connect the mandible to the temporal bone. The synovial membrane lines the capsule.

Department of Oral & Maxillofacial Surgery, Goa Dental College & Hospital, Bambolim, Goa, India

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_53

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 53.1** Bony structures of TMJ

This membrane produces synovial fuid which aids in the lubrication and nourishment of the joint. The lateral ligament also known as temporomandibular ligament has a horizontal and an oblique component which stabilizes the joint. The strength of the lateral ligament may be partly responsible for the fracture at the neck of condyle just below the insertion of the ligament [3]. The medial and lateral discal ligaments which are present inside the capsule are also called collateral ligaments. These ligaments connect the disc to the poles of the condyle. In addition to these ligaments, there are two non-capsular ligaments, namely, sphenomandibular and stylomandibular which may have a limited function.

#### **53.2.4 Muscles of Mastication**

There are four muscles of mastication, namely, the medial and lateral pterygoid, masseter, and the temporalis. Lateral pterygoid is attached to the pterygoid fovea at the condylar neck and is responsible for the displacement of the condylar fractures. Change in the direction of resultant forces post fracture will alter the function of the mandible during various excursion movements.

#### **53.2.5 Vascularisation**

The arterial blood supply to the TMJ is derived from the two terminal branches of the external carotid artery, namely:


It may be noted that the condyle receives blood supply from three sources


This may explain the reason for the fractured condyle to remains viable even after stripping of the periosteum during the surgical procedure as the lateral pterygoid muscle remains attached to the fractured fragment [4]. The venous drainage starts in the retrodiscal plexus which drains into the superfcial temporal and maxillary veins that join to form the retromandibular vein, which in turn drains into the external jugular vein.

#### **53.2.6 Innervation**

It is imperative to understand the innervation of the joint so as to minimize the complications following fracture of the mandible and its management. Both the sensory and motor innervation is encountered while approaching the joint. The sensory nerves are auriculotemporal, masseteric, and posterior deep temporal. Auriculotemporal nerve crosses the condyle medial to it and lies in contact with the condylar neck and capsule [5]. It is encountered in the preauricular incision and may result in postoperative complications.

#### **53.2.7 Facial Nerve**

It is the key nerve that transverses the face, and it is liable for the motor function of the muscles of facial expression. This nerve transverses the temporoparietal fascia and fnally divides into fve terminal branches in the parotid gland (Fig. 53.2). Hence all the extraoral approaches for the condylar fractures are designed keeping the facial nerve in mind. Al-Kayat and Bramley [6] found the nerve was at an average distance of 20 mm with a range of 8–35 mm from the anterior margin of the auditory canal. This is the reason the preauricular incision is given in the skin crease near the tragus or placed endurally. The neck of the condyle can be exposed via the transparotid approach. In this approach the condyle is reached through the space between the temporozygomatic and buccocervical trunks of the nerve. This results in a direct and safe approach to the neck of the condyle. The marginal mandibular nerve is encountered in the submandibular or periangular approach. This branch may further subdivide into two or more branches [7]. As a rule, the submandibular incision is given 2 cm below the lower border of the mandible to prevent paresis of the lower lip.

**Fig. 53.2** Terminal branches of facial nerve with Al Kayat and Bramely's [6] measurements for trunk of facial nerve. (A) .8–3.5 cm, (B) 2.4–3.5 cm, (C) 1.3 cm

#### **53.3 Biomechanics of Condylar Fracture**

U-shaped mandible supports the condyles on either side. There are two major movements while opening the mouth, rotational, and translational which occur in the inferior and superior compartments, respectively. Mandibular function is characterised as a class III lever with the joint being the fulcrum [8]. The musculature applies the force between the joint and the masticatory load (Fig. 53.3).

#### **53.3.1 Mechanism of Injury**

Trauma causing condylar fracture was explained by Lindahl [9]. It is important to understand the pattern as it gives the type of injury sustained (Fig. 53.4).


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 53.3** Function of mandible as class III lever

condyle on the opposite side. Fracture is usually at the base of the condyle.

3. Combination of the above two is seen in a road traffc accident and may result in more severe injuries.

An external force applied generally gets distributed over the entire mandible. However these forces result in the fracture of the subcondylar region which is weak and are subject to tensile stresses. A counter-coup injury is often noted in the condylar region. This prevents displacement of the condyles into the middle cranial fossa especially in bilateral fractures resulting from injuries over the chin.

#### **53.3.2 Efect of Condylar Fracture**

The signs and symptoms seen following trauma are due to the functional loss resulting from the disruption of the local anatomy. Following trauma a protective mechanism is triggered. It is generally expected that due to premature contact on the fractured side, excessive forces would be generated during loading of the non-fractured site on mastication. However, it is noted there is a shift of mean force vector towards the non-fractured site which results in protecting the fractured site during biting [10]. This results in neuromuscular adaptation. An increase in the muscle activity on the nonfractured side and a decrease of active force on the opposite 1088

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**Fig. 53.4** Mechanism of fracture of condyle

side results in this process. Hence most of the masticatory forces are directed towards the non-fractured site and resulting in less neuromuscular adaptation on the fractured site. Refer to the article by Ellis et al. [8] for a comprehensive understanding of the biological considerations of fractures of mandibular condyle.

#### **53.3.3 Adaptation to Fracture**

Following condylar fracture of the mandible, patients adapt to the injury by compensation mechanism which is divided as follows:


Intervention by the surgeons either by open or closed reduction minimizes the dental compensation. It is noted that there is a decreased masseter activity on the fractured site transferring load to a non-fractured site. This results in neuromuscular adaptation which may also be a protective phenomenon [8]. In case of an open reduction, there is minimum amount of neuromuscular adaptation. Usually a closed reduction results in an articulation which is inferior and anterior to the articular eminence which may limit the transitional movement. This can be avoided by open reduction and fxation. Minimum complications have been reported in the studies evaluating closed reduction in treatment of condylar fractures as pain and mouth opening were the only criteria which were evaluated. A statistically signifcant reduction in the incidence of malocclusion and lateral deviation on opening, along with an improved protrusive and laterotrusive movements, were noted in patients treated with surgical therapy vis-á-vis closed therapy in a recent meta-analysis report [10]. Compared to closed reduction where skeletal and neuromuscular adaptation is seen, in open reduction only neuromuscular adaption will take place following treatment.

#### **53.4 Classifcation of Condylar Process Fractures**

Condylar fractures can be described as a fracture line above the mandibular foramen that runs from the posterior border of the ramus to sigmoid notch or the condylar head (Fig. 53.5). Literature mentions numerous classifcations of condylar fractures. Most classifcations described the fracture based on the anatomical site, displacement, and fracture level, inclined towards close reduction. With the advancement of imaging modalities and better understanding of open reduction procedures, classifcations which are relevant are discussed.

Various terms describing the condylar fractures have appeared in the English literature (Fig. 53.6):


In 1927 **Wassumund** [11] differentiated between the head and neck fractures of the condyle. Early classifcation only described anatomical position but had no relevance in treatment as it did not document the angulation of displacement or dislocation. Condylar fractures were classifed as:


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**Fig. 53.5** Area of condylar fracture

**MacLennan** [12] was the frst to differentiate between simple bending, displacement, and dislocation fractures of the condylar process.

Class I: no deviation (bending)

Class II: deviation (bending) at the fracture level


**Spiessl and Schroll** [13]. A classifcation well accepted in the European literature, which differentiated between fractures of the base and neck of the condyle, it also noted the range of angulation with deviation, displacement, or dislocation (Fig. 53.7).

	- IIIa: ventral
	- IIIb: medial
	- IIIc: lateral
	- IIId: dorsal

There are numerous modifcations of Spiessl and Scholl classifcations and were given over a period of time as a result subtypes has evolved especially in type V and VI fractures. Modifcations included Rasse [14], Neff et al. [15], Hlawitschka and Eckelt [16], and Loukota et al. [17].


**Fig. 53.6** (**a**) No displacement. (**b**) Deviation. (**c**) Displacement. (**d**) Dislocation (deviation). (**e**) Dislocation (displacement)

**Fig. 53.7** (continued)

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**Fig. 53.7** (continued)

**Fig. 53.8** Modifed classifcation Type A, B, C

**Lindahl** [9] gave the most comprehensive classifcation. Although descriptive, it is a complicated classifcation [9].

	- (a) Condylar head
	- (b) Condylar neck
	- (c) Subcondylar/condylar base
	- (a) Bending/deviation with medial overlapping segments
	- (b) Bending/deviation with lateral overlapping segments
	- (c) Bending/displacement without overlapping
	- (d) Nondisplaced fracture without deviation
	- (a) No dislocation
	- (b) Slight dislocation
	- (c) Moderate dislocation
	- (d) Severe and/or complete dislocation
	- (a) Horizontal
	- (b) Vertical
	- (c) Compression fracture

#### *Lindahl's Defnition*


A most common classifcation of diacapitular fractures was given by He et al. [18]. The types of fractures that can be recognized are (Fig. 53.9):


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**Fig. 53.9** Classifcation of diacapitular fractures (Type M not shown in fgure)

Loukota et al. [19] proposed a system of classifcation for condylar processes fractures of the mandible. This classifcation was adopted by SOR group which is based on a line A drawn perpendicular from the lowest portion of the sigmoid notch to the posterior border of the mandible. This helps in identifying the anatomy of the mandibular ramus even in cases following severe trauma. A clarifcation is also given on the condylar head fracture, and it clearly defned the term minimal displacement.


**AO Foundation** in 2010 expanded on Ellis [20] classifcation with the determination of "high-neck" and "low-neck" fractures in the online AO Surgery Reference, which pro-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 53.10** (**a**) Dicapitular fracture. (**b**) Condylar neck. (**c**) Condylar base

vided a great detail to the location of "high and low" fractures as explained by Loukota:


Neff et al. [21] published the Comprehensive AOCMF Classifcation System: Condylar Process Fractures. It is a system that highlights fracture location, identifcation, displacement, comminution, and dislocation. Location of the condylar fracture is clearly identifed:


In the early days classifcation systems for the condylar fractures were entirely focused in locating the fracture. This was followed by systems which added the relation of the condyle with the adjacent structure. Loukota [19] gave a

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 53.11** AO foundation classifcation

classifcation which accurately locates the fracture with reference to treatment which is a simple classifcation to follow.

The aim of classifying the condylar fractures of the mandible is to locate the type and nature of the fracture which in turn will give a clear understanding of the nature of injury. This in turn will help the surgeon make a decision on the modality of treatment which may be open or closed.

#### **53.5 Incidence and Pattern**

In the facial skeletal, one of the most common bones to fracture is the mandible. Analysis of the fracture of different anatomical sites of the mandible revealed that there was a 10–40% incidence of condylar fractures [22–24]. Ellis et al. [25] published a study that showed condyle fractures represented 29.3% of all mandibular fractures. Zachariades et al. [26] stated that 72% of the condylar fractures were associated with other mandibular fractures. Isolated condylar fractures were rare, and occurrence of malocclusion was more dependent on the site of fracture. Incidence of fractures of condylar base were 57%, neck 31%, and head 12% as reported by Maclennan [27]. Incidence of condylar head was the least with the majority fractures at the condylar base. Frequency of unilateral fractures is higher than the bilateral fractures.

The highest incidence of mandibular fractures in males was 20–30 years and females 30–40 years [25] with the male-tofemale ratio 3:1 [26]. Condylar fracture can result from direct or indirect trauma. The degree, direction, magnitude, and point of application of force determine the severity of displacement [27]. Personal violence [28] followed by fall [29– 31] is the most common aetiology of condylar fractures.

#### **53.6 Clinical Features**

The patient may show mild to severe signs and symptoms following a condylar fracture. These are entirely dependent on the amount of displacement of the fractured fragments. Condylar fractures infrequently occurred in isolation and are generally associated with fractures of other sites of the facial bones. Surgeons may overlook subtle clinical features.

*Signs and symptoms:*


#### **53.6.1 Condylar Fractures: Unilateral**


#### **53.6.2 Condylar Fractures: Bilateral**


#### **53.6.3 Radiographic Assessment**

Condylar fractures can be evaluated by a number of conventional views. A set of two radiographs are usually taken perpendicular to each other for optimum evaluation. However the assessment has become more descriptive with availability of specialized radiographs. Various views which can be taken to evaluate the condylar fracture are as follows (Fig. 53.13):


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**Fig. 53.12** Occlusion post condylar fracture. (**a**) Unilateral condylar fracture of the left. (**b**) Bilateral condylar fracture

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**Fig. 53.13** A case of unilateral fracture of the right side of condyle with a left body of mandible. (**a**) OPG. (**b**) PA mandible. (**c**) Coronal view. (**d**) Axial view. (**e**) 3D view of the CT scan

However it may be noted that with conventional radiography, very limited information is available. CT scans in the three plains, namely, coronal, axial, and sagittal, with volumetric studies can reveal the true picture of the fracture both for the terms of evaluation and treatment planning. MRI are essential to evaluate the disc injuries specially in dislocation and intracapsular condylar fractures; however MRI are not taken as a routine practise

#### **53.7 Management**

Historically there has been no clear agreement among the surgeons on the line of management of the fractures of the condyle. The goals of treatment which were enumerated by Walker [32] (Box 53.2) are well accepted.

#### **Box 53.2. Treatment Goals** [32]


#### **Box 53.3. Indications for Open Reduction Zide and Kent's** [33]

#### **Absolute**


#### **Relative**


#### **Box 53.4. American Association of Oral and Maxillofacial Surgeons [34]**


Literature has indicated that closed reduction has been the treatment of choice. This may be due to the complexities involved with open reduction. Surgical approach is technically demanding and associated with complications in inexperienced hands. As a result, some centres have exclusively treated condylar fractures by closed reduction. However as opposed to closed reduction, a few centres follow a protocol for management where open reduction is treatment of choice. Patients managed by surgical treatment have a superior outcome in term of post-treatment malocclusion, protrusion, laterotrusion, and lateral deviation during mouth opening. However, there was a higher infection rate as compared to non-surgical treatment. However, there is no statistical difference in post-treatment pain and maximum mouth opening in the two modalities of management [10]. Management can be divided as non-operative and operative (Box 53.6).

#### **53.7.1 Non-operative**

Some patients can be managed by observations provided they have a minimal nondisplaced fracture, dentate with a stable occlusion and having minimum pain. An important factor is that the patient must be complaint. At the onset of the treatment, patient must be explained about the possibility of additional treatment in the form of closed reduction which may be required.

Protocol followed is as follows:


**Box 53.5. Indication for Open and Closed Reduction Fonseca** [35] adapted from references [36–43]

#### **Absolute**


#### **Strong evidence for open reduction**


**Mixed evidence for open reduction**

• Moderate condylar displacement, 10–45°

#### **When to treat with closed reduction**


#### **Box 53.6. Management of Condylar Fractures**

#### **Non-operative:**

• Observation, physiotherapy, etc.

#### **Operative:**

	- (i) Surgeon preference
	- (ii) Fracture location
	- (iii) Type of fxation

#### **Box 53.7. Factors Taken into Consideration for Treatment**


#### **Box 53.8. Closed Reduction**

#### **Advantages**


#### **Disadvantage**


#### **53.7.2 Closed Reduction**

Closed reduction is a misnomer. It is never possible to achieve anatomic reduction as seen in management of other fractures. Closed reduction relies on the functional adaptation where a stable occlusion is achieved. Advantage of this technique is that it is minimally invasive and may not require hospitalization. It is entirely possible to carry out the procedure under local anaesthesia. However adaptation is never complete in adults as opposed to children. It may be possible to treat all types of condylar process fractures by this technique, but the surgeon must exercise his judgement based on the case and patient requirements. Closed reduction may involve the following:


#### **53.7.3 Open Reduction and Fixation**

This modality is technically challenging due to the complexities in terms of anatomy, approach, and fxation. It has been observed that by achieving anatomical reduction irrespective of the type of fxation used, it will result in restoring back the skeletal architecture. This in turn would require only neuromuscular adaptation for full recovery of the patient. According to the reports, this may be the reason for open management to be superior to the closed [36].

*Surgical approaches* to the condylar fracture are entirely dependent on the following factors (Fig. 53.14):


Incisions used to approach the fractures are divided as


#### **Box 53.9. Open Reduction and Fixation**

#### **Advantages**

	- Early function

#### **Disadvantage**


## **53.7.3.1 Submandibular/Periangular**

(Fig. 53.15a, b) (Video 53.1)

This is an approach most maxillofacial surgeons are familiar with in their practise popularly known as Risdon approach. It exposes the base along with the neck of the condyle. Incision can either be parallel to the lower border or placed in a skin crease for maximum cosmetic results. For the condylar, fracture's incision is extended backward and upward to give a maximum exposure hence also referred to as periangular incision. The marginal mandibular nerve is protected by marking the incision 2–3 cm below the lower border of the mandible. Incision transverses through the skin, subcutaneous fat, and platysma. A superior platysmal dissection will expose the marginal mandibular nerve; however this may not be necessary. After dissection of the platysma, superfcial layer of deep cervical fascia is transected; this may expose the facial artery and vein. These may be required to be ligated and refected superiorly. This will protect the marginal mandibular nerve. Then pterygomasseteric sling is divided and periosteum refected to expose the lower border of the mandible. This gives an adequate exposure for osteosynthesis.

A modifcation of the submandibular/periangular approach known as the high submandibular approach or the high cervical transmassetric anteroparotid approach provides good aesthetics and reduces the chances of damage to the facial nerve [44]. A curved incision measuring three to fve cm in length is placed about 1 cm from the angle of mandible [45]. This is followed by layered dissection. An avascular pouch is created superiorly, and the pterygomasseteric sling is identifed. Stripping the masseter muscles of its attachments will lead to the exposure of the fracture [46] (Video 53.2).

**Fig. 53.14** Various incisions possible for condylar fractures based on location

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**Fig. 53.15** (**a**) Incision for submandibular/periangular approach. (**b**) Area exposed marked green in the mandible

#### **53.7.3.2 Retromandibular** (Fig. 53.16a, b)

#### (Video 53.3)

Entire posterior border can be exposed via the retromandibular approach [47]; hence this approach is useful in treating fracture of the condylar neck and the base. The anatomic structures encountered in this approach are the main trunk of the facial nerve and retromandibular vein. It has two main variations transparotid and retroparotid. In both the variation marking of the incision is 5–10 mm below the lobule of the ear, parallel to the posterior border usually 3–4 cm long.

#### **Transparotid Approach**

In this approach incision is extends from the skin to the subcutaneous tissue, and it is undermined to reach the parotid capsule which is divided horizontally between the path of the buccal and zygomatic branches of the facial nerve. Dissection is carried out parallel to the direction of the facial nerve branches, and it is not important to locate the branches. Pterygomasseteric sling is sectioned, and periosteal fap elevated to expose the posterior border of the mandible.

#### **Retroparotid Approach**

In this approach parotid gland is lifted rather than transected to approach the posterior border of the mandible. Incision in this approach is placed more posterior as compared to transparotid approach as a result exposure is also restricted. After the parotid fascia is identifed, dissection is carried out behind the gland. The gland is lifted to expose the posterior border; from here the dissection carried out is the same as the transparotid approach.

V. Dhupar

## **53.7.3.3 Preauricular Approach** (Fig. 53.17a, b)

or parotid fstula. Drains can also be placed.

parotid fascia should be sutured tightly to prevent sialocele

#### (Video 53.4)

This incision is most commonly used by the surgeons in the TM joint surgeries. Diacapitular fractures are approached via this approach [48]. Branches of facial nerve are involved in this approach along with the superfcial temporal artery and vein. Incision is placed along the crease of the skin following the tragus and helix of the ear which can be extended in the temple region. This extension on the temple minimizes traction and prevents weakness of facial nerve. Incision is carried from the skin to the subcutaneous tissue till the white glistening temporal fascia is reached. Root of the zygoma is palpated, and an oblique incision is given parallel to the frontal branch of facial nerve. Superfcial temporal fascia is incised, and a periosteal elevator is inserted below the fascia to strip the periosteum of the zygomatic arch. This will expose the capsule of the temporomandibular joint. Capsule is incised in an open method to expose the head of the condyle. The neck is exposed by doing a subperiosteal dissection. Closure is done in layers frst being the capsule followed by temporalis fascia, subcutaneous tissue, and the skin. The main disadvantage of this approach is an unaesthetic scar. This can be overcome by placing the incision endurally. The scar hides behind the tragus, but it can cause perichondritis.

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**Fig. 53.16** (**a**) Incision for retromandibular approach. (**b**) Area exposed marked in mandible (dark green, retro parotid exposure; light green, transparotid exposure)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 53.17** (**a**) Preauricular approach incision. (**b**) Area exposed marked in the mandible

#### **53.7.3.4 Retroauricular Approach**

This is an approach which will provide best cosmetic results. However major disadvantage is that it can result in stenosis of the external auditory canal. Also, the closure takes a longer time. Incision runs parallel to postauricular fexure approximately 3 mm behind it. Skin followed by postauricular muscles and fascia overlying mastoid are incised. External auditory canal is identifed and completely transected at bony cartilaginous junction. Temporalis fascia is identifed, and from here dissection followed is similar to preauricular approach to expose the condylar head. Closure is done in layers with a special attention given to the external auditory canal.

#### **53.7.4 Reduction**

After the adequate exposure of the fractured fragments reduction is achieved under direct vision. If the distal fragment is placed laterally, reduction tends to be easy. However, in most of the cases, the fragments tend to be displaced medially resulting from the pull of lateral pterygoid muscle. A medially displaced fragment must be lateralized before an attempt is made to reduce the fracture. For easy manipulation, a plate with a single screw is fxed on the distal fragment. This will help in easy lateralization of the distal fragment and prevent the fragment from slipping back as the lower end of the plate acts as a rest on the proximal segment. Before an attempt is made to reduce the fracture, manual traction is applied to the mandible so that the vertical height of the posterior mandible is restored. This can be achieved as follows (Fig. 53.18a–d):


Once the fracture is reduced with the help of a clamp in the lowermost hole of the plate, pressure is applied to keep the fractured end in place. Figure 53.19a–d shows the reduction and fxation of a medially displaced condyle fracture.

In a case where two plates are planned for fxation, the smaller plate along the anterior border of the condyle is fxed frst with a screw. Once the anterior plate is fxed on the distal segment, similar steps are followed as mentioned earlier for single plate for reduction and fxation.

Sequencing the case of multiple fractures is as follows:

1. Fractures with contralateral condylar fractures—Fractures in the tooth bearing anterior segment are fxed before the condyle is fxed.

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**Fig. 53.18** (**a**) Manual digital reduction. (**b**) Traction using bite block. (**c**) Transosseous wiring. (**d**) Towel clip


### **53.7.5 Fixation Techniques** (Fig. 53.20a–d),

(Case 1: Fig. 53.21a–b), (Case 2: Fig. 53.22), (Case 3: Fig. 53.23a–e), (Case 4: Fig 53.24a–d)

The most signifcant advances that have taken place in the management of fracture of condylar process include the osteosynthesis material and the technique. Fixation with titanium plates and screws has given optimal results when adequate bone, proper site selection with proper techniques

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 53.19** (**a**) Medially displaced condylar fracture. (**b**) Fracture lateralized. (**c**) Distal segment secured with a plate. (**d**) Fracture reduced

followed [49]. At the time of surgery fxation, technique is selected based on the following parameters:


Fixation can be in the form of one plate, two plates, hybrid plates, lag screws, or restorable plates. Studies have shown that use of two plates is superior to one plate [40, 50]. Two plates must be used for lower level fractures to overcome tension and stress in the neck region by placing plates along the anterior and posterior border in a triangular fashion (Fig. 53.20a–d). In cases where there is limited bone, available fixation can be done with heavier single plate. Single plate is fixed along the long axis of the condyle. There are many types of hybrid plates available. These are designed to incorporate the principle of two plates in a single plate. However, this makes the plates bulky as a result it may be at times difficult to fix them especially when there is limited bone available. Irrespective of the type of plate used, there should be at least two screws on either side of fracture.

Fixation of condylar head is a challenge because of the limited space available and the fractures are intracapsular. In addition, there could be multiple small fragments and associated injury to the disc and the capsule which may be required to be repaired. Several osteosynthesis techniques are available for fxation like the mini plates, stainless steel wire, standard lag screws, resorbable screws, resorbable pins, and cannulated lag screws (Fig. 53.25). Reduction and fxation of the condylar head is technically challenging as the small fragments can easily necrose if stripping of the muscle is done. Use of two lag screws would be idle as it will prevent the reduced fragments from displacement during function, but times it may not be possible to fx two screws due to limited space Table 53.1 [51].

Intraoral endosocpic approach for treatment of condylar fractures is given in detail in Chap. 54 of this book.

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**Fig. 53.20** (**a**) Single plate. (**b**) Two plates. (**c**) Lambda plate. (**d**) Delta plate

**Case 1: Fig. 53.21** (**a**) OPG view showing left condyle fracture (**b**) Post operative OPG showing single plate fxed via retromandibular transparotid approach

**Case 2: Fig. 53.22** (**a**) Intra operative view showing two plates fxed for condyle fracture via retromandibular transparotid approach. (**b**) Post operative radiograph of showing fxation with two plates

**Case 3: Fig. 53.23** (**a**) PA view showing right condyle fracture. (**b**) Intraoperative view via retromandibular transparotid approach shows the displaced condyle. (**c**) Reduction and fxation done with Lambda plate. (**d**, **e**) Post operative PA view and OPG showing the fxed Lambda plates

#### **Box 53.10. Functional Exercise: Rehabilitation Targets [52]**


#### **53.8 Condylar Fractures in Children**

The most common fracture seen in the maxillofacial region in children is fracture of the condylar process [53]. Condyle is unique in children as there is a very thin cortical bone surrounding a highly vascular cancellous bone. This can result in a comminuted type of fracture also called mushrooming. Condylar fractures can result in defnitive deformities, both in terms of function as well as

**Case 4: Fig. 53.24** (**a**, **b**) Pre operative PA view and OPG showing fracture left condyle. (**c**, **d**) Post operative PA view and OPG showing the fxed Delta plate via Periangular approach

a facial asymmetry in cases of inappropriate treatment. Intracapsular fractures can result in retardation of growth [54, 55] or in excessive growth on the fractured site [56]. Remodelling of the condyle is inversely proportional to age [9, 25, 26]. Children have a better adaptation than the adults. Adaption in children is skeletal, neuromuscular, as well as function. In adults only functional adaptation is seen. For this reason, literature has supported conservative management of fracture of the condylar process. It is paramount to rehabilitate the patient with the restoration of minimum mouth opening, lateral excursion movement with stable occlusion. However, a long-term follow-up showed 50–53% of patients had complaints even though minor in nature irrespective of the type of treatment carried out [57]. Early mobilization is recommended in children below 15 years. Patients are encouraged to be on soft diet to avoid pain. In cases where an open bite is present, guiding elastics will help in restoring the occlusion. There is no concrete evidence of prolonged period of maxillomandibular fxation.

1110

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tures of the mandibular condyle

**Table 53.1** Comparison of different fxation methods used for frac-

**Case 5: Fig. 53.26** Shows improperly reduced fracture condyle which has been fxed in a dislocated position of the condyle-arrow points towards the plate fxed in wrong position


**53.9 Complications of Condylar Fractures**  (Case 5: Fig. 53.26) (Case 6: Fig. 53.27a–c)


**Case 6: Fig. 53.27** (**a**) Chronic infection left side condyle region following reduction and fxation, (**b**) CT scan showed osteomyelitis like changes at left condyle (**c**) the fractured infected plate removed

#### **Box 53.11. Recent Advances [49]**


#### **53.10 Conclusion**

There have been numerous controversies in management of condylar fractures. They have ranged from which classifcation to use, surgical approach, type of fxation, and outcome of the treatment. But till date even with all the advances available to us, we still cannot agree on the two schools of thought for management of condylar fracture that is closed or open. Danda et al. [38] concluded in their study that there was no difference in treatment outcome in both the groups. This can be debated as it is not possible to compare the two modalities of treatment in absolute terms. Although it is pointed out that there are better results in function with open reduction and fxation, there are inherent complications that are only seen in cases treated by open reduction [62] such as nerve injuries and scars.

In an alternative interpretation of evidence, Leon A Assael [63] opined that both open and closed reduction have a critical role in management of condylar fractures. Treatment outcome such as full pain free range of movement and good aesthetics is seen in both the groups. Malocclusion, functional defcit, and internal derangement are seen irrespective of line of treatment. Over the years, complications noted in open reduction have reduced with the better understanding and improvement of technique, but it can be burden on the patient. These complications can only be weighed against the functional advantage patient gets in open reduction and fxation. Treatment of a condylar fracture will entirely be dependent on multiple factors.

To conclude it can be safely stated that management of condylar fractures should be patient centric not entirely based on absolute indications mentioned by various authors. Generally, in children and dentulous adult patients, closed reduction is the choice of treatment, whereas open reduction and fxation would be the choice of treatment for the patients with multiple fractures of mandible, panfacial trauma, partially or totally edentulous jaws, and underlying medical conditions preventing maxillomandibular fxation. Finally, function should be considered as an important parameter while formulating a treatment plan along with the resources available and skill of the surgeon.

#### **References**


ized prospective, multicenter study with special evaluation of fracture level. J Oral Maxillofac Surg. 2008;66:2537–44.


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# **54**

## **Intraoral Endoscopic Approach for Treatment of Condylar Fractures of the Mandible**

Frank Wilde

#### **54.1 Introduction**

The literature is replete with techniques regarding the open reduction and fxation of the condylar fractures of the mandible. The extraoral approach is preferred by the majority of surgeons in comparison to the intraoral approach. Nevertheless, open reduction and internal fxation by an extraoral approach has the evident risk to cause transient or even permanent facial nerve injury [1–4], leads inevitably to a facial scar [1, 5], and can course salivary fstulas, sialoceles [1, 6], Frey syndrome, or disturbance of the great auricular nerve [1]. In contrast, an intraoral approach is minimizing these abovementioned risks and facial scars can be avoided in general [7, 8].

Silverman in 1925 was the frst person to mention about the intraoral approach to condylar fractures [9]. However, at that time, the surgeons were facing several diffculties treating those fractures due to a lack of adequate instruments. Fritzemeier and Bechthold developed the 90-degree angular screwdriver, and it served as a milestone in the intraoral management of condylar neck fractures. In their study, there were 32 fractures of which 2 cases showed early failures. Other cases during follow-up showed minor deviation from axis, but there were no evident problems in the temporomandibular joint function [10].

Based thereupon, several authors were reporting about the use of an intraoral approach treating condylar fractures surgically. Forty-eight cases of displaced and shortened mandibular condyle fractures were treated by an intraoral approach and studied by Mokros and Erle in 1996. In 2/3 of the treated fractures, the reduction was successful, and no

F. Wilde (\*)

Department of Oral and Maxillofacial Surgery, University Hospital, Ulm, Germany e-mail: frank.wilde@uni-ulm.de

signifcant complications were noted in the intraoperative or postoperative period.

TMJ function was good in 90% of the patients, 43% were free of symptoms, and 47% had minor dysfunction. The authors came to the result that proper reduction of the bone fragments is most important for therapeutic success [11].

Schön et al. [8] compared in a study an intraoral endoscopy-assisted approach with an extraoral approach for the treatment of condylar fractures. A reduced risk of facial nerve damage and no visible scars were the major conclusion of the study, and they also opined that intraoral endoscopic approach is a reliable technique for treating condylar fractures [8]. Veras et al. [12] were looking in their study on 25 patients with condylar fractures which were treated surgically by an intraoral approach. The mean mouth opening postoperatively was 4.8 cm. Patients postoperatively did not have clicking of the joint, facial nerve weakness, or pain of the muscles or the joint. They opined that intraoral reduction allowed the anatomic ramus height to be restored and that the functional results were acceptable [12].

Other authors like Jensen et al. [13] or Schneider et al. [14] were not so enthusiastic about the outcome of surgicaltreated condylar fractures employing an intraoral approach [13, 14]. Jensen et al. in 2006 stressed on the fact that intraoral approach for the condylar fractures is very technically demanding and there is a chance of getting postoperative complications [13]. Schneider et al. [14] compared in a retrospective study 21 fractures which were treated with an intraoral approach with 24 fractures which were reduced by an extraoral perimandibular approach. In their study, the cases treated by intraoral approach showed suboptimal radiologic fndings, and the patients' subjective feelings pointed to less favorable clinical results. They put forward the suggestion that fractures which do not require extensive manipulation and fractures which can be reduced exactly under a limited view only should be approached intraorally. For all other fractures, they recommend extraoral approaches [14].

© The Association of Oral and Maxillofacial Surgeons of India 2021 1115

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_54

Department of Oral and Plastic Maxillofacial Surgery, Armed Forces Hospital, Ulm, Germany

#### **54.2 Surgical Technique**

From the authors' experience, fractures of the condylar base and the low and medial part of the condylar process can be addressed typically by the following described technique. Treating high condylar neck fractures is demanding and requires experience in using such an approach. Fractures of the condylar head or the transition zone between the neck and head cannot be reached with this approach, and extraoral incisions are still required when this kind of fractures is getting treated surgically.

For the below-described technique, a team of three surgeons (one leading surgeon and two assistant surgeons) are highly recommended.

#### **54.2.1 Special Surgical Instruments and Devices**

To facilitate open reduction and internal fxation of condylar fractures via an intraoral approach with predictable results, special equipment is mandatory.

The most important instruments are a 90° angled screwdriver and drill (Fig. 54.1a). The screwdriver should have necessarily a sliding screw-holder which facilitates to hold the screw and plate together (Fig. 54.1b), because positioning a plate with one hand and fxing the screw with the other hand is not appropriate and will lead to unsuccessful procedures. Self-retaining screwdriver-bits or even selftapping screws should be avoided as well. The authors recommend a straight 90° angled screwdriver with the aforementioned sliding screw-holder and centric-positioned screwdriver-bits. Screwdrivers with eccentric-positioned screwdriver-bits show a lower height indeed.

Besides the 90° angled screwdriver and drill, extra-long instruments in the form of raspatories and reposition hooks have to be recommended insistently (Fig. 54.2). They simplify the manipulation and reduction of the fractured condyle with a good direct view into the operation site. Using standard confgurated instruments results in less vision due to obstructing the view by the operator's hands.

An appropriate light-intensive headlight is necessary for proper illumination of the operation site (Fig. 54.3).

A 4 mm caliber 30° angled endoscope has to be recommended as well. In combination with a special retractor in which the endoscope can be inserted, a good visualization, especially of the posterior border of the ramus, can be achieved (Fig. 54.4).

In addition, a special retractor with a fber-optic light guide which can be positioned buccally to the posterior border of the ramus enables good illumination of the surgical site (Fig. 54.5). Nevertheless, having an appropriate headlight, this instrument seems to be dispensable.

It can be further useful to fx the patient during surgery in a Mayfeld head clamp as it is commonly used by the neurosurgeons. This allows traction with the retractors without any movement of the head.

Besides the described instruments, there are several special instruments and devices available on the market to facilitate open reduction and internal fxation using an intraoral approach. However, from the authors' experience, the aforementioned instruments and devices are the most helpful in treating condylar fractures by an intraoral approach.

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**Fig. 54.1** (**a**) 90° angled screwdriver and drill. (**b**) Sliding screw-holder which facilitates to hold the screw and plate together (Medartis, Basel, Switzerland)

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**Fig. 54.2** Extra-long instruments in the form of raspatories and reposition hooks (Karl Storz, Tuttlingen, Germany)

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**Fig. 54.3** LED headlight (KLS Martin, Tuttlingen, Germany)

#### **54.2.2 Surgical Access**

By extending the standard vestibular incision in a superior direction along the ascending ramus, the ramus and the condyle region can be exposed intraorally (Fig. 54.6). The approach is following Obwegeser's principles of avoiding visible scars by extending his approach to the mandibular ramus for sagittal split osteotomy. During the incision of the oral mucosa, the anatomical course of the buccal nerve has to be taken into account. The dissection of the mucoperiosteal fap starts from the mandibular corpus in the region of the frst molar to mandibular angle and far up to the condyle until the facture line can be explored. To get an appropriate

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**Fig. 54.5** Retractor with a fber-optic light guide (Karl Storz, Tuttlingen, Germany)

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**Fig. 54.4** (**a**) 4 mm caliber 30° angled endoscope (asterisk) and retractor in which the endoscope can be inserted (hash symbol). (**b**) Retractor with inserted endoscope (Karl Storz, Tuttlingen, Germany)

1118

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**Fig. 54.6** Intraoral approach to the condyle region by extending the standard vestibular incision in a superior direction up the ascending ramus

visualization of the condylar neck region, the mucosa including the fbers of the temporal muscle had to striped from the coronoid process up to or even higher than the mandibular notch. During dissecting the posterior border of the mandibular ramus, the retromandibular vein has to be taken under consideration. Coagulation in this region has to be done carefully, due to the anatomical proximity to the facial nerve which is running laterally in the parotid gland. This is the region where the facial nerve may be damaged during the procedure. In addition to coagulation, vigorous traction can damage the facial nerve in this location as well.

#### **54.2.3 Surgical Procedure**

After dissection to get suffcient access to the condylar neck region, the displaced condyle has to be identifed. The best instrument for this is the extra-long raspatorium depicted in Fig. 54.2. During this procedure, the ramus has to be distracted. This can be performed by pulling the mandible caudally by hand. Another option is to fx one mini-screw in the

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mandibular angle to twist a wire around, which is diverted out of the skin in the mandibular angle region by a stab incision. However, this leads to a small extraoral scar.

For this maneuver, a full relaxation of the patient by the anesthesiologist is recommended. Due to the very low risk for facial nerve damage employing this approach, this can be done without increasing this risk.

For medial displaced condyles in high condylar neck fractures, it is sometimes helpful to perform a temporary osteotomy of the coronoid process to get better access for repositioning. A later re-fxation of the osteomized coronoid process by a miniplate is in theory not needed but recommended by the authors (Fig. 54.7).

Once the dislocated fragment is identifed, it has to be repositioned anatomically. MMF cannot be recommended in all cases. In some cases, it can be helpful to get a stable reduction during osteosynthesis; however, in most cases, MMF is not very helpful. This decision has to be made individually case by case.

In most cases, the reposition of the proximal fragment is not stable from the beginning (Fig. 54.8). Therefore, the authors recommend to drill the frst screw hole in the condyle fragment close to the fracture line in the region of the sigmoid notch. A four- or fve-hole 1.0 mm up to 1.2-mm-thick miniplate is fxed in this hole with a 5- to 6-mm-long screw with a diameter of 2.0 mm. The screw should not be tightened completely. Then the reduction of condyle fragment

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**Fig. 54.8** Endoscopic view after repositioning of a condylar neck fracture

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**Fig. 54.9** Endoscopic view after fxation of a four-hole miniplate close to the sigmoid notch with two screws adjacent to the fracture line

can be achieved by pulling on the miniplate with one of the extra-long reposition hooks. By visual control of the repositioned fragment, the miniplate should now be fxed in the ramus part of the fracture close to the sigmoid notch by eccentric drilling of the screw hole for fracture line compression during screw insertion. After fxing the second screw, the frst screw has to be tightened completely (Fig. 54.9).

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**Fig. 54.10** Endoscopic view after fxation of a fve-hole miniplate at posterior border with two screws adjacent to the fracture line

Once this is facilitated, often a small gap and faring can be identifed at the posterior border of the condylar neck. To close this gap, a second four- to fve-hole miniplate has to be fxed at the posterior border of the condylar neck. Here also the hole has to be drilled in the condyle fragment close to the fracture line. First, the plate has to be fxed in this hole and should be aligned along the posterior border of the condylar neck respectively the ramus. Again, the screw should not be tightened completely at this stage. After exact anatomical reposition of the condyle, the next screw is now drilled for compression osteosynthesis in the ramus part of the ramus close the fracture line and immediately fxed with the fourth screw (Fig. 54.10). The third screw is then tightened completely to stabilize the fracture. After attaining control of the anatomical correct reposition with the endoscope or in low condylar neck fractures even with a simple dental mirror, the other screw holes in both plates are drilled and fxed, starting with the plate at the posterior border and ending with plate close to the sigmoid notch. Figure 54.11 shows the fnal endoscopic view with the two plates fxed. Figure 54.12 is illustrating the recommended sequencing of plate and screw positioning to facilitate open reduction and internal fxation via an intraoral approach using two miniplates.

In addition, the authors recommend intraoperative imaging with a 3D C-arm device at the end of the procedure when available (Fig. 54.13). This allows the intraoperative radiologic control and documentation of the reduced fracture and of the position of the plates in a multiplanar view and enables an immediate intraoperative correction when the result of the

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**Fig. 54.11** Endoscopic view after complete fxation of a condylar neck fracture with two miniplates. One four-hole plate in the region of the sigmoid notch and a second fve-hole miniplate at posterior border

procedure is not satisfactory. This reduces the risk for revision surgeries considerably [15, 16].

When the result is satisfactory, the intraoral mucosa has to be closed in the standard way like every intraoral incision. Even when the fracture is reduced and stabilized with success, the authors still recommend a light MMF with elastics strained over two or four MMF screws or arch bars for approximately 1 week for slight immobilization and guidance into the proper occlusion. In case of a postoperative insuffcient occlusion, a prolonged functional treatment as in nonsurgical treated condylar fractures with elastics or an orthodontic device like an activator or bionator has to be recommended.

#### **54.2.4 Osteosynthesis Material**

As mentioned before, the author is recommending the usage of two miniplates. The plate at the posterior border is responsible for the stability primarily, whereas the plate in the region of the sigmoid notch prevents faring of the distal fragment during function additionally.

For osteosynthesis, 1.0-mm up to 1.2-mm-thick miniplates can be recommended (Fig. 54.14). It can be favorable to use 1.2-mm-thick miniplates at the posterior border due to stability reasons. The screws should be usually 5–6 mm long with a diameter of 2.0 mm. Locking screws

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**Fig. 54.12** Recommended sequencing of plate and screw positioning to facilitate open reduction and internal fxation via an intraoral approach using two miniplates

are not necessary and should never be used for the screw holes which are adjacent to the facture line. These holes should be drilled eccentric to achieve compression at the facture line. In modern osteosynthesis systems, locking and non-locking screws can be used with the same plates. Using such a system, it may be advantageous to use locking screws for the fracture-distant screw holes. Nevertheless, as mentioned before, locking screws are not needed in this technique.

Besides standard miniplates, there is the option for the use of so-called 3D plates or special designed condylar neck plates (Fig. 54.15). However, from the authors' experience, plating with two miniplates enables the aforementioned successive repositioning and fxation of the facture most easily and leads to suffcient stability.

There are new developments of anatomically preformed 3D condylar neck plates with integrated reposition wings for the posterior border and the sigmoid notch (Fig. 54.16). Whether these kinds of plates are benefcial or not has to be investigated in the future.

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**Fig. 54.13** Intraoperative imaging with a 3D C-arm device (Ziehm, Erlangen, Germany) at the end of the procedure and multiplanar view of the surgical result

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**Fig. 54.14** 1.0-mm and 1.2-mm-thick standard miniplates (DePuySynthes, Zuchwil, Switzerland)

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**Fig. 54.15** 3D miniplate (asterisk) and special condylar neck plate (hash symbol) (DePuySynthes, Zuchwil, Switzerland)

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**Fig. 54.16** (**a**) Anatomically preformed 3D condylar neck plates with integrated reposition wings for the posterior border and the sigmoid notch (KLS Martin, Tuttlingen, Germany). (**b**) Displaced right condylar neck fracture. (**c**) Condylar neck fracture after repositioning and fxation employing an intraoral approach

#### **54.3 Complications**

There is no much difference in complications by treating condylar factures via an intraoral approach in comparison to all other treatment options. Postoperative infection is the most common complication followed by malocclusion. Dysfunctional degeneration of the injured joint can lead to joint clicking, pain, reduced mouth opening, and mandibular deviation during opening and closing. Even severe arthritis or condylar resorption can occur up to the total destruction or loss of the joint. Hardware failure in form of plate fractures or loosening of screws can be seen occasionally as well.

In addition to the avoidance of any visible extraoral scar, the biggest advantage in comparison to all extraoral approaches for surgical treatment of condylar fractures is the very low complication rate concerning facial nerve injuries, salivary fstulas, sialoceles, Frey syndrome, or disturbance of the great auricular nerve.

#### **54.4 Conclusion**

The described intraoral approach for the treatment of condylar fractures is favorable for fractures of the condylar base and the condylar process. The biggest beneft and advantage in comparison to all extraoral approaches is the very low complication rate concerning facial nerve injuries and the **Table 54.1** Advantages and disadvantages of an intraoral approach for the treatment of condylar fractures



avoidance of extraoral scars. A disadvantage is the need for special equipment to facilitate this technically demanding procedure with regular success (Table 54.1).

#### **54.5 Case Scenario**


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**Fig. 54.17** (**a**) 3D reconstruction of the preoperative CT scan showing the medial displaced condylar process fracture right and slightly displaced paramedian fracture left. (**b**) Coronal view of the preoperative CT scan showing the medial out of the fossa displaced condylar process


#### **References**

1. Rozeboom AVJ, Dubois L, Bos RRM, Spijker R, de Lange J. Open treatment of condylar fractures via extraoral approaches: A review of complications. J Craniomaxillofac Surg. 2018;46(8):1232–40.

fracture right. (**c**) Postoperative panoramic X-ray showing well-suffcient reduced and with miniplates stabilized fractures paramedian left and at the condylar process right


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## **Maxillary Fractures**

Oommen Aju Jacob and Akhilesh Prathap

#### **55.1 Introduction**

Complex midface trauma has challenged the diagnostic and operative skills of surgeons through the decades. Robert Marciani in his ffty year review article dated 1993, vividly described the challenges faced by early surgeons regarding the clinical and radiological diagnosis of mid face fractures and the compromised surgical results that may ensue [1].

#### **55.1.1 History (Table 55.1)**

In an area so anatomically complicated as the midface, the lines of fracture produced in the middle third are classifed based upon the experimental studies of René Le Fort in 1901 [2]. The earliest known writings of maxillofacial fractures were recorded in the Edwin Smith papyrus in 1650 BC. Hippocrates who is often portrayed as the "Father of Medicine" described a myriad of facial injuries around 400 BC and his insight provided the basis for bandages and single jaw interdental wiring as methods of fxation and stabilization of facial fractures. Over the subsequent centuries, there appeared many techniques which in essence were variations of what Hippocrates had described. In the nineteenth century, Charles Fredrick Reiche provided the frst detailed treatise on maxillary fractures [3]. It was also in the same century that Garretson and Blair advocated mandibularmaxillary fxation with the aid of splints to primarily treat maxillary fractures.

In 1901, a French surgeon René Le Fort published his classic paper on midfacial fracture patterns. He inficted blunt facial trauma on cadavers, then subsequently removed the soft tissue and examined fracture patterns of the facial skeleton. This study has ever since been the basis for the description of maxillary fractures.

O. A. Jacob (\*)

Department of Oral and Maxillofacial Surgery, Ananthapuri Hospitals and Research Institute, Trivandrum, Kerala, India

Kerala Institute of Medical Sciences, Trivandrum, Kerala, India

A. Prathap Pushpagiri College of Dental Sciences, Thiruvalla, Kerala, India

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K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_55

**Table 55.1** Milestones of maxillary fractures


**55**

#### **55.1.2 Surgical Anatomy/Osteology**

The middle third of the facial skeleton is made up of the following bones (Fig. 55.1)


The middle third of the face is made up of a number of bones which rarely fractures in isolation. The complex nature of the midface is such that it will withstand the forces of mastication from below and provide protection in certain areas for vital structures. The middle third of the facial skeleton consists of a series of bone struts (buttresses) passing upwards from the upper teeth to the bones of the skull [4] (Fig. 55.2).

The relative fragility of the midface skeleton makes it act as a cushion for trauma directed towards the cranium from an anterior or anterolateral direction. The facial skeleton can be designated by this famous fgure, where the skull is similar to a helmet, the midface is similar to a matchbox (crumble zone) and the mandible is similar to a hockey stick (Fig. 55.3). The most common causes of facial fractures in the adult population are assaults and motor vehicle accidents [5].

**Fig. 55.2** Vertical and horizontal buttresses of the facial skeleton (Also refer Fig. 60.9 and Table 60.2)

#### **55.1.3 Applied Anatomy of the Midfacial Bones**

The midface is composed of the nasal, zygoma, maxilla, ethmoid and its conchae, palatine, inferior concha and vomer which are collectively referred to as the middle third of the facial skeleton. The facial bones in isolation are comparatively fragile but gain strength and support as they articulate with each other. It is this strength that has often been described as the facial buttresses which Manson alluded to when describing the vertical and horizontal struts that support the facial skeleton [6]. The horizontal pillars are formed by the frontal bar (composed of the supraorbital rims and nasal process of the frontal bone), the zygomatic arch, the infraorbital rims and the nasal bridge and fnally the alveolar process of the maxilla. The vertical pillars are the medial pillar formed by the piriform rims which continues superiorly as the frontal process of the maxilla. The zygomatic buttresses which continue superiorly with the lateral orbital rims form the lateral pillars, and the most caudal pillars are the pterygoid plates.

#### **55.1.3.1 Maxilla**

The maxilla consists of a central body and four processes, namely, the frontal, zygomatic, alveolar and palatine process. The body is hollowed out and contains the maxillary sinus. It is pyramidal shaped with the base being the medial surface facing the nasal cavity and the apex being elongated into the zygomatic process. It has an orbital or superior surface which forms the foor and rim of the orbit, a malar or anterolateral surface which forms part of the cheek and a posterolateral or infratemporal surface which contributes to the infratemporal fossa. The base is rimmed inferiorly by the alveolar process. The alveolar process houses the dental arch with the sockets varying in size according to the teeth. The palatine process is a horizontal process from the body to the alveolar process and medially articulates with the palatine process of the opposite maxilla, while posteriorly it articu**Fig. 55.3** Helmet, matchbox and hockey stick to illustrate relative bone strength (the matchbox is the crumble zone)

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lates with the horizontal plate of the palatine bone. The zygomatic process is an extension of the anterolateral surface of the body which contributes to the zygomaticomaxillary suture. The frontal process projects upwards to articulate with the maxillary process of the frontal bone as well as the nasal bone anteriorly and the lacrimal bone posteriorly.

#### **55.1.3.2 Vascular Supply and Innervation**

The blood supply to the maxilla and the palatine bones is through the periosteum, the incisive artery and the greater and lesser palatine arteries. The internal maxillary artery lies posterior to the maxillae and the palatine bones and anterior to the pterygoid plates of sphenoid.

The maxillary nerve enters the caudal maxilla ventral to the orbit via the maxillary foramen and runs through the maxilla in the infraorbital canal giving off branches to supply the maxillary cheek and teeth. The nerve then exits the maxilla at the infraorbital foramen.

#### **55.2 Classifcation**

#### **55.2.1 René Le Fort1901 [2]**

Maxillary fractures were classifed by René Le Fort based on his experiments on cadavers with low velocity unidirectional frontal trauma. Although the present-day maxillary fractures are caused due to high velocity multi directional trauma, the Le Fort classifcation is still widely followed due to its simplicity and the levels of anatomic differentiation it offers. Other authors have attempted classifcations based on the anatomical sites and based on the involvement of the occlusion. Marciani modifed the basic Le Fort classifcation by adding frontal bone and zygomatic fractures.

#### **55.2.1.1 Le Fort I**

#### **Low Level Fracture/Guerin Fracture**

The fracture line extends backwards from the lateral margin of the anterior nasal aperture below the zygomatic buttress to cross the lower third of the pterygoid laminae. The fracture also passes along the lateral wall of the nose and the lower third of the septum to join the lateral fracture behind the tuberosity (Fig. 55.4a–c).

#### **55.2.1.2 Le Fort II**

#### **Pyramidal or Sub-zygomatic Fracture**

This fracture runs from the thin middle area of the nasal bones down either side, crossing the frontal processes of maxillae into the medial wall of each orbit; the fracture line crosses the lacrimal bone behind the lacrimal sac before turning forwards to cross the infraorbital margins slightly medial to or through the infraorbital foramen. The fracture now extends downwards and backwards across the lateral wall of the antrum below the zygomaticomaxillary suture and divides the pterygoid laminae about half way up.

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**Fig. 55.4** (**a**, **b**) Le Fort I fracture lines. (**c**) CT of Le Fort I fracture

Separation of the block from the base of the skull is completed via the nasal septum and may involve the foor of the anterior cranial fossa (Fig. 55.5a–d).

#### **55.2.1.3 Le Fort III**

#### **Transverse or Supra-zygomatic Fracture**

The fracture runs from near the frontonasal suture transversely backwards and parallel with the base of the skull and involves the full depth of the ethmoid bone including the cribriform plate. Within the orbit the fracture passes below the optic foramen into the posterior limit of the inferior orbital fssure. From the base of the inferior orbital fssure, the fracture line extends in two directions: backwards across the pterygomaxillary fssure to fracture the roots of the pterygoid laminae and laterally across the lateral wall of the orbit separating the zygomatic bone from the frontal bone. In this way the entire middle third of the facial skeleton gets separated from the cranial base (Fig. 55.6a–c).

Le Fort classifcation does not take into consideration:


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**Fig. 55.5** (**a**, **b**) Le Fort II fracture lines. (**c**) CT of Le Fort II fracture showing the midface segment impacted (red arrows). (**d**) Clinical image of case in **c**, showing the impacted area right side Le Fort II (yellow arrow)

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**Fig. 55.6** (**a**, **b**) Le Fort III fracture. (**c**) CT of Le Fort III fracture (the fracture lines shown with red arrows)

### **55.2.2 Killey's Classifcation (1965)** [2] (Table 55.2)

**Table 55.2** Killey's classifcation


### **55.2.3 Rowe and Williams's Classifcation (1985)** [2] (Table 55.3)

#### **Addenda**


#### **55.2.4 Marciani (1993: Modifcation of Le Fort Fractures)** [1]

Fractures involving the cranial base and other midface fracture confgurations, including severely comminuted segments of the facial skeleton, were not classifable by the

**Table 55.3** Rowe and Williams's classifcation

traditional Le Fort scheme. Hence Marciani proposed a more precise system of describing fracture patterns to defne the fracture confguration, establish an accurate diagnosis and to determine potential surgical approaches (Table 55.4).

### **55.2.5 Palatal Fractures Classifcation: Hendrickson's Classifcation (1998)** [7] (Figs. 55.7, 55.8, and 55.9; Table 55.5)

**Table 55.4** Marciani's modifcation of Le Fort fracture classifcation


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**Fig. 55.7** Hendrickson's classifcation of palatal fractures. (**a**) Type Ia, (**b**) Type Ib, (**c**) Type II, (**d**) Type III ,(**e**) Type IV, (**f**) Type V, (**g**) Type VI

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**Fig. 55.8** (**a**) CT of Hendrickson's type C fracture. (**b**) Clinical image of case of **a**, showing the midline diastema

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**Fig. 55.9** CT of midline palatal fracture with splayed segments, note the posterior displaced fragment, temporary bridle wire has been placed between upper central incisors

#### **55.3 Clinical Features** (Box 55.1)

#### **55.3.1 Le Fort I Fractures**

Gross facial swelling or facial disfgurement is generally not a feature of Le Fort I fractures, but oedema around the upper lip may occur. Soft tissue injury along the upper lip along with tearing of gingivae may occur due to the causative impact. There can be mobility of the upper dentoalveolus when digital pressure is applied. Mobility of the maxilla at the Le Fort I level must be differentiated from extended maxillary dentoalveolar fracture. Malocclusion may occur if the fracture is displaced or impacted. Dorsal and caudal pull of the medial pterygoid muscles can contribute to the posterior displacement of the maxilla and the resultant anterior open bite (Fig. 55.10a, b). Bilateral epistaxis is rare although emphysema may occur if the patient blows his nose. Ecchymosis in the upper buccal sulcus is a frequent fnding. Percussion of the maxillary teeth produces a dull cracked cup sound. In case of inferiorly displaced Le Fort I fractures, the patient may have to keep the mouth open to accommodate the increased vertical dimension. Due to the extreme downward displacement of the maxilla, the nasal base is lost, leading to stretching of the soft tissues of that area, which makes it possible to see directly into the nares.

The posteriorly impacted Le Fort I fracture may result in an anterior open bite and in these cases the maxilla may be immobile. Usually the impacted maxilla can be mobilized by grasping the maxillary teeth and applying a frm anterior pull. A grate may be felt due to the movement between the fractured segments. In posteriorly impacted fractures, there may be damage to the cusps of maxillary teeth usually in the premolar region, caused by the upward impact of the mandibular teeth at the time of the trauma. The complete Le Fort I fracture may be associated with a split along the median palatal suture. Sometimes more than one fracture line may be present in the palate, so that either one or both fragments may be mobile (Fig. 55.11a–c).

#### **55.3.2 Le Fort II Fractures**

Marked facial disfgurement resulting from circumorbital ecchymosis and gross oedema can be a feature of Le Fort II fractures. Frequently the patient will not be able to open

**Table 55.5** Hendrickson's classifcation: of Palate fractures

#### **Box 55.1 Clinical features of Le Fort fractures**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 55.10** (**a**, **b**) A posteriorly telescoped Le Fort I fracture maxilla clinically manifesting as anterior open bite

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 55.11** CT images (**a**, **b**) showing a right zygomatic complex fracture associated with a Hendrickson's type B fracture where the right posterior alveolar and palatal segment was displaced palatally and extruded, causing the occlusal discrepancy (crossbite) as seen in **c**

his eyelids to allow an ocular examination. Subconjunctival haemorrhage may be present, the posterior limit of which cannot be identifed. Bilateral peri-orbital oedema and circumorbital ecchymosis (described as circumorbital as it follows the shape of the orbicularis oculi muscle) are described as racoon eyes or panda facies. There can be severe oedema of the face which is sometimes described as moon facies. Enophthalmos in case of orbital foor fractures may go undetected due to oedema. Considerable lengthening of face with posterior gagging of teeth can also occur. Bilateral epistaxis is common, and CSF leak may be present. The loss of maxillary prominence may result in a dish face appearance. If the fracture line passes through the infraorbital canal there can be associated paresthesia in the infraorbital nerve region. While clinically mobilizing the maxilla in a Le Fort II fracture, transmitted mobility may be felt at the infraorbital rim and the frontonasal suture. Figure 55.12 shows a CT image where Le Fort II and III lines are seen

#### **55.3.3 Le Fort III Fractures** (Also see Fig. 49.5)

This fracture is clinically similar to the Le Fort II fracture but can demonstrate a more serious condition. Bilateral ecchy-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 55.12** CT image showing Le Fort I and II fractures. Note that maxilla is rotated to the right side with canting on the left side.

mosis with circumorbital oedema may close the eyes completely. As in Le Fort II, the posterior limit of the subconjunctival haemorrhage cannot be seen. The lengthening of the face occurs due to the loss of bony fxation to the base of the skull. The fattening of the face from the disrupted zygomatic bones is usually masked by the gross oedema. The fracture passes above the Whitnall's tubercle and so the support by Lockwoods, suspensory ligament is lost. This results in hooding of upper eyelid which becomes obvious when the oedema subsides. Gagging of occlusion and shift of the maxillary midline may occur. Gross posterior displacement of the maxilla can result in the soft palate touching the posterior part of the tongue causing airway and speech impairment. As with other maxillary fractures, percussion of teeth might produce a cracked cup sound. .

The clinical differentiation between Le Fort II and Le Fort III fractures can be assessed by palpating for step deformity in the infraorbital rim in the former.

#### **55.3.4 Unusual Fracture Patterns**

The Le Fort fractures may manifest without the classic fracture patterns as described above. An unilateral fracture at Le Fort I level may occur (identifed through imaging) which warrants no intervention unless accompanied by a palatal fracture causing occlusal derangement and/or mobility. Such a unilateral fracture pattern can cause unilateral gagging causing open bite on the contralateral side

The clinician must be aware of the two types of Le Fort I fractures, the mobile and impacted variants; lack of mobility should not be presumed as absence of fracture.

#### **55.4 Radiographic Examination**

It is diffcult to diagnose fractures of the middle third of the face with plain flms and CT scans have now largely replaced radiographs.

The commonly used radiographs for identifying maxillary fractures are occipitomental view (OMV) 10° and 30° and paranasal sinus view 37° (PNS -Waters view).

While assessing maxillary fractures with these radiographs, Mcgregor-Campbell and Trapnell's lines and Dolan's lines (elephant of Rogers) may be kept in mind [8].

#### **McGregor-Campbell's lines**:

These lines were described by McGregor and Campbell for ease of searching on an occipitomental view 10-degree frontal projection.


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 55.13** McGregor-Campbell and Trapnell's lines


The **four S's described by Delbalso, Hall and Margarone** [8]

In PNS view, the following four features are to be verifed/compared with the unaffected side


#### **Dolan's Lines** [8] (Fig. 55.14)

**Dolan's lines** are the collective name given to three lines described by Dolan and Jacoby that aid in evaluating for maxillofacial fractures on an occipitomental skull radiograph. They are usually used as an adjunct to McGregor-Campbell lines.

• **Orbital line (line 1)** traces the inner margins of the lateral, inferior and medial orbital walls and the nasal arch.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 55.14** Dolan's lines (also see Fig. 56.22)


#### **Elephant of Rogers** [8]

Lee Rogers pointed out that the second and third lines of Dolan give the outline of the head of an elephant.

#### **55.4.1 CT Scans**

CT scans are now the gold standard for a defnitive diagnosis in fractures of the maxilla. A CT scan in all three planes (axial, sagittal and coronal) along with a 3D reconstruction will aid the surgeon in accurate assessment of fracture patterns and also will aid in preoperative planning. The surgeon must never rely on the 3D CT alone but should correlate the images with those obtained in axial sagittal and coronal planes, as there could be reconstruction-related errors which appear as fracture lines or bone defects. CT scan-based fracture patterns may be classifed as low, middle or high energy, defned solely by the pattern of segmentation and displacement in the CT scan [9].

#### **55.5 Treatment of Maxillary fractures**

The primary aim of treatment of maxillary fractures is to reestablish the dental occlusion and masticatory effciency. The contribution of the maxilla to the projection and contour of the midface has also to be considered in the management of maxillary fractures and requires a clear understanding of the facial buttress system, subunit anatomy and interrelationships of the various bones [10]. This aesthetic aspect is often compromised by associated injuries of the zygomatic complex, nose and orbits.

The basic principles of the treatment of maxillary fractures are:


Factors that infuence improved treatment outcome in maxillary fractures are:


#### **55.5.1 General Considerations in Treatment of Maxillary Fractures**

Proper reduction of maxillary fractures is the key to achieving good dental occlusion and needs proper clinical examination of the fracture pattern after all the accessible fracture sites are exposed. A repeat study of the CT scans (axial, coronal and 3D) and correlation with the exposed maxilla will aid the surgeon in planning adequate reduction and rigid fxation. It should be kept in mind that the fractured maxilla is usually displaced backwards and downwards and hence the reduction should in the forward and upward direction. To obtain reproducibly good results, even with the most extensive facial dislocations, the surgeon should restore the facial architecture at the Le Fort I Level [12]. In rare occasions, lateral en bloc displacement of the maxilla is seen, and this requires transverse reduction to achieve the correct dental occlusion. A depressed zygomatic fracture can physically prevent reduction of the maxilla. Hence the fractured zygomatic bone should be reduced prior to manipulating the maxilla.

The most useful instruments for reduction of the maxilla are the Rowe's disimpaction forceps. Even in cases where the fractured maxilla appears to be minimally displaced, it is prudent to mobilize the bone with the disimpaction forceps so as to overcome any bony interferences and thus freeing the maxilla completely. When using this paired forceps, care should be taken to avoid injury to the anterior teeth and also to the palatal mucosa. Mobile, extruded and proclined anterior teeth are at particular risk, and an assistant should closely observe the anterior teeth, while the surgeon is manipulating the fractured maxilla. It would also be advisable to obtain informed consent regarding mobility or loss of these teeth. Trauma to the nasal foor is inevitable when mobilizing the maxilla using the reducing forceps, and some nasal bleeding is usually observed, but this rarely requires a nasal pack.

frmed by:


Problems arise when the patient has few or no teeth and when there is gross comminution of maxilla. In these situations the surgeon has to make do with whatever landmarks are available, and in such cases compromised functional and cosmetic results are not uncommon.

Direct manipulation at the fracture lines is sometimes required especially when the fractured maxilla is telescoped into the superior normal bone. Care must be taken to prevent additional fractures at the bony margins during direct manipulation as this would make fxation more demanding. Using tie wires at the zygomatic buttresses, around the second maxillary premolars/frst molars bilaterally and through anterior nasal spine is often useful to physically disimpact and pull the maxilla forwards and upwards thus ensuring good reduction.

When the maxilla is fractured in multiple levels (e.g. Le Fort I and III levels), reduction using the disimpaction forceps alone may not be adequate. The dental occlusion can be achieved, but the midface projection may be compromised. Here also a combination of reduction with disimpaction forceps, direct manipulation at the fracture site and the use of the above mentioned tie wires is often indicated.

Once adequate reduction of the fractured maxilla is obtained, it is mandatory that rigid maxillomandibular fxation (MMF) is applied. In almost all cases, well-adapted maxillary and mandibular arch bars are required as this ensures multiple points for the MMF. Failure to obtain rigid MMF or manually maintaining the dental occlusion during fxation can result in post-operative occlusal discrepancies. If surgical reduction and fxation of the maxilla has to be delayed, elastic traction will be helpful in obtaining a functional occlusion. The use of MMF screws defnitely saves operating time but can be problematic if elastic traction is required later.

If the mandibular condylar fracture exists, this should be reduced and fxed prior to the MMF. Failure to do so may result in an open bite due to loss of posterior mandibular height.

#### **55.5.2 Suspension Wiring**

Internal wire suspension involves sandwiching the fractured portion of the maxilla between the mandible and the superior part of the facial skeleton/skull that is not fractured. The use of internal suspension wires is more or less obsolete unless there is severe comminution which precludes rigid internal fxation. Suspension wiring may also be the surgeon's choice

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 55.15** Various types of suspension wiring employed for midface fractures

when there is presence of severe infection at the site of surgery (Fig. 55.15).

#### **55.5.3 Rigid Internal Fixation**

Although many wiring techniques were practised in the past, rigid internal fxation with titanium bone plates and screws of suffcient rigidity is now the standard of care. For internal fxation of the maxilla, titanium bone plates and screws of suffcient rigidity are used. For providing rigidity, screws with an outer diameter of 1.5 mm is commonly used.

#### **55.5.4 Approaches to the Maxilla**

When treating a very high Le Fort I fracture and in Le Fort II and III fractures, it may be necessary to use one or more of the following incisions, which are described in chapter 56 and 57 of this book:


#### **55.5.4.1 Maxillary Vestibular Approach**

The maxilla can be approached through a variety of incisions, the most common being the maxillary vestibular approach. In addition to providing access to the lower part of the entire midfacial skeleton, this approach results in a hidden intraoral scar. This approach may result in disruption of the attachments of the facial muscles of the nasolabial region; hence careful repositioning during closure is recommended to avoid unaesthetic changes to the face. The muscles of importance are the nasalis group, the levator labii superioris alaeque nasi, the levator labii superioris, the levator anguli oris and the orbicularis oris. The vestibular incision and subsequent dissection causes stripping of origin/insertion of most muscles originating in the maxilla. These muscles tend to get reattached in a shortened manner due to the action of the zygomaticus muscle. Deepening of the alar groove and splaying of the alar bases, nostrils and nasal tip may occur following lateral displacement of the nasal modiolus. Soft tissue fullness loss in the naso-alveolar region may result in thinning and retraction of upper lip, reduced vermillion exposure and a obtuse nasolabial angle. Detachment of the levators of the upper lip may cause down turning of the corner of the mouth (Fig. 55.16).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 55.16** Maxillary vestibular incision with adequate gingival cuff. Yellow arrows denoted the Le Fort I fracture lines

#### **Clinical Tips for approaching the Le Fort fracture via maxillary vestibular incision**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 55.17** A clinical situation where the separate vestibular maxillary incisions were given to approach anterior maxilla, due to deep through and through lip laceration upper lip extending down to the frenum region

Early intervention (7–10 days) with open reduction and fixation is the treatment of choice for maxillary Le Fort I fractures. Restoration of normal facial contour and occlusion is considered as optimal outcome of treatment. Bone reconstruction should be completed as early as possible to minimize shrinkage, stiffness and scarring of soft tissues [12].

In complex panfacial fracture management, many authors have stressed the importance of managing the Le-Fort fracture while reconstituting the facial architecture [13, 14].

#### **55.5.5 Fixation of Le Fort I #**

Adequate fxation of the fractured bone depends on two factors, namely, the rigidity of the plate and the friction between the bone fragments (buttressing of the bony segments). When a gap exists between the bone ends, the latter factor is missing. In these cases, non/fbrous union can result if the masticatory forces are greater than the rigidity of the plate. As a general principle, the paranasal and zygomatic buttresses must be rigidly fxed. The plates should be well adapted especially where the bone stock is poor. At least two screws must be present on either side of the fracture and more the number of screws, better the, load sharing, between the plate and the subjacent bone. Opposed to this is when there is no bone buttressing and the plate has to be 'load bearing'. Also a minimum of two threads of the screw should engage the cortical bone. This may be a problem in thin areas as the anterior wall of the maxillary sinus and the alveolus where roots are present. In the edentulous maxilla, the bone quality is often compromised, and the lower end of the plate may need to be placed on the alveolus. This may necessitate removal of the plate prior to prosthodontic rehabilitation.

Obtaining rigid fxation becomes diffcult when the buttresses are comminuted. If only one buttress is amenable for plating the reduction at this fracture interface along with reconstitution of the occlusion must be used as the template for repositioning the maxilla. When all the buttresses are comminuted, the surgeon has to "eye ball" the maxilla into the reduced position. In these situations, a long-span plate extending from the body of the zygomatic bone to the relatively thick bone in the area of the anterior nasal spine with or without a bone graft is often the only option available to maintain the vertical position of the foating maxilla. It has been stated that the lip-tooth relationship is helpful in deciding the position of the reduced maxilla, but in practice this is of limited use.

Loss of bone at the buttresses may require the use of primary bone grafts [10]. Though it has been suggested that a In essence the decision to graft will depend on:


gap of more than 5 mm at the buttresses requires a graft, rigid plate fxation followed by MMF is often enough to ensure bony healing.

Primary bone grafting can be done using iliac bone (Fig. 55.26), split calvarium or split ribs. The calvarium is the preferred source because of the following reasons:


The disadvantage is that these grafts are brittle and cannot be contoured. The bone graft has to be mortised to ft the defect and must be fxed rigidly to the plate or lag screwed.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 55.18** A clinical situation where the defect in the anterior wall maxilla due to comminution of the wall was partly covered by fxing the free segment (red arrow). The long-span plate from the buttress to the anterior maxilla region can also be seen

Incisions for open reduction can be placed from frst molar to frst molar regions through a vestibular approach for

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 55.19** The surgeon stands behind the patient and applies the disimpaction force, while the head is stabilized by the assistant surgeon

©Association of Oral and Maxillofacial Surgeons of India

wide exposure of the fracture sites. Rowe's disimpaction forceps and/or Hayton-Williams forceps can be used for mobilizing and reducing the fracture into position. The impacted type of Le Fort I fracture manipulation has to be done by grasping the maxilla with two pairs of Rowe's disimpaction forceps. Osteotomizing the maxilla should be considered if there is signifcant interval between the time of trauma and surgery. Whenever possible a passive reduction of the maxilla with condyles frmly seated in their correct position should be ensured to avoid post-operative anterior open bite (Figs. 55.19, 55.20, and 55.21).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 55.21** Use of Hayton-Williams forceps

Use of Rowe's disimpaction forceps Rowe's disimpaction forceps are available as paired (right and left) instruments Each instrument has two blades, one for engaging the palate (to be padded before use to avoid injury to the palatal mucosa) and one to be inserted through the nostril The instrument has an outward bend at the handle which aids in the use of two forceps simultaneously After engaging the forceps, the maxilla has to be moved in all planes to ensure adequate mobilisation


After reduction the maxilla should be placed into maxillomandibular fxation. The fxation of the fracture sites (fourpoint fxation) is done at the vertical pillars of nasomaxillary and zygomaticomaxillary (lateral piriform rim and zygomatic buttress regions) for which the preferred plates and screws used are 1.5-mm thickness with 6-mm long screws. In the zygomatic buttress regions, 2.0-mm profle plates also can be used. The mini-plates are fxed as close as possible to the lateral pyriform rim as the bone is thickest there. Usually stabilization of the fracture is achievable even if any three of the four buttresses are fxed. Apparently, gross communition at one of the buttress regions will not cause a signifcant risk of inadequate stabilization. The associated anterior wall of the maxillary sinuses is generally not fxed due to the relative thin nature of bone in this region. The larger free bone fragments can be repositioned and immobilized using wires or be used for reconstruction of orbital foor defects. The circumvestibular incision is closed with running resorbable sutures after ensuring that the midline of upper lip coincides with the facial midline (Fig. 55.22).

Maxillomandibular fxation of up to 6 weeks also can be considered as alternative for treatment though the results may be less satisfactory with added morbidity to the recovering patient. The readers are advised to refer chapter 50 to read about closed reduction / wiring and intermaxillary fxation techniques.

#### **55.5.6 Fixation of Le Fort II Fractures**

The pyramidal fracture has the apex of the fracture located at the nasofrontal suture region or at the midnasal bone level. The Le Fort II fractures are ideally fxed at the frontonasal suture region, bilateral infraorbital rims and also both zygomaticomaxillary buttresses. However in majority of the clinical situations fxation at the infra orbital rims and the zygomatic buttress regions gives reasonably good results. Most Nasal bone fractures associated with Le Fort II fractures can be adequately managed by closed reduction techniques. This may require the anaesthetist to change nasal intubation to oral intubation. A submental intubation may also be considered at the beginning of the procedure. If the nasofrontal segment is unstable, fxation of the area can be done through various approaches (existing laceration, Gull wing approach, etc.). A maxillary vestibular incision can frequently provide access to infraorbital fracture alignment and fxation in some cases. The lower eyelid approaches are not always mandatory

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 55.22** The zygomatic buttress and paranasal buttress fxed in a classical Le Fort I fracture maxilla

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 55.23** Le Fort II fracture lines at the infraorbital rim area may have to be accessed directly, if required, especially with associated zygomatic/orbit fractures. In this case the lateral orbital rim reconstruction is done via combined access from left sub ciliary incision and left supra tarsal incision

for fxation unless simultaneous exploration and reconstruction of orbital foors are also planned.

In Le Fort II fractures that are complicated by an associated palatal fracture, surgical splints may be helpful in obtaining adequate reduction. Placement of maxilla mandibular fxation will ensure accurate alignment of midface structures (Fig. 55.23).

#### **55.5.7 Fixation of Le Fort III Fractures**

These are complex fractures which rarely occur in isolation and results in a dysjunction of the facial skeleton from the base of the cranium. The ideal repair time should be within 10–14 days following the injury but may get delayed due to neurosurgical issues and other comorbidities.

Incision design for Le Fort III fractures should facilitate adequate access for reduction as well as fxation of the nasofrontal, frontozygomatc and in some cases the zygomatic arches. Using existing lacerations for access avoids need of a coronal incision, as this allows for complete visualization, reduction and fxation of the frontal area and zygomatic arches. A lateral brow or upper blepharoplasty (supra-tarsal fold) incision may be used to approach the lateral orbital rims. Also in such cases, a thicker plate (2.0) placement at the lateral orbital rim may be benefcial. A coronal approach may have to be considered if bilateral fronto-zygomatic and nasofrontal fracture fxation is planned.

The occlusion is a reliable indicator of adequate reduction in cases where direct visualization of the fractured segment is not possible.

In Le Fort III fractures associated with other fractures (open facial/condyle fractures), various surgical sequences can be followed, which is discussed in chapter 60 on Panfacial fractures.

Rarely, Le Fort fractures may present without mobility, but show occlusal disturbances like crossbite, open bite or loss of intercuspation. These can be managed by using traction elastics but at times warrant mobilization and subsequent rigid fxation [15].

**Fig. 55.24** Infraorbital plate exposure

©Association of Oral and Maxillofacial Surgeons of India

#### **55.6 Complications of Le Fort Fractures**  (Table 55.6)

**Table 55.6** Complications of Le Fort fractures

Unlike many other areas of the midface, the palatal bone is relatively thick, and hence palatal fractures are not common. A palatal split makes reduction and fxation of maxillary fractures more diffcult mainly due to the transverse instability which can cause medial collapse or outward splaying of the maxilla. The use of the Hayton-Williams forceps along with the disimpaction forceps will control outward splaying of the maxilla but at the risk of medially displacement of the dentate segment of the maxilla. Moreover, the use of all the three forceps effectively requires some amount of surgical expertise.

Moss et al. [16] have proposed a classifcation for palatal fractures. There is no consensus regarding the management of palatal fractures, but various options have been suggested.


Transpalatal wires are simple to apply and do not have the problems of soft tissue dehiscence and infection seen in the more invasive methods [17]. However, the reduction of the palatal fracture cannot be ensured, and the wires can be cumbersome to the patient as it affects speech and swallowing. If the palatal wires are passed through an infant feeding tube or a small gauge urinary catheter, injury to the dorsum of the tongue can be minimized. It is also noticed that palatal wires tend to become slack after a few days, and then their value in reduction and fxation of the fracture is questionable. Moreover, these wires are not an option in the edentulous maxilla.

Direct exposure and plate fxation are surgically demanding, but the fracture can be reduced and fxed under direct vision. Ceinfuegos et al. have described the technique of fxing the plate over the palatal mucosa, but this plate would have to be removed at a later date [18]. An alternative would be to use a resorbable plate and screws.

Ma et al. has documented the use of self-drilling screws on either side of the palatal fracture with wires to fx the fracture [19].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 55.25** Oronasal fstula in a patient who had sustained palate fracture

Palatal fractures of the sagittal or parasagittal variety can be stabilized by placing a mini-plate across the fracture line on the labial side. Occasionally the prominence of the anterior nasal spine has to be reduced to facilitate mini-plate placement.

The transpalatal reduction should be supplemented by fxation at the zygomaticomaxillary and nasomaxillary buttresses and the use of an arch bar [20].

Palatal fractures accompanied by soft tissue lacerations often cause a serious challenge to the surgeon regarding its management. The healing of the palatal soft tissue laceration is dependent on the exact reduction of the palatal vault and stabilization. Overzealous attempts at closure of the laceration without accurate reduction may compromise wound healing. A tension-free closure of the palatal mucosa is imperative for wound healing. In some cases, the ensuing oronasal communication will have to addressed secondarily (Fig. 55.25).

#### **55.7.1 Surgical Splints**

Concomitant fractures of the palate present additional challenges to the treatment of Le Fort fractures. They complicate the re-establishment of proper width and height of the maxilla. Depending on the fracture type, patient comorbidities and associated injuries, either closed reduction and wiring or rigid fxation may have to be performed. Dental impressions can be obtained and occlusion assessed prior to surgery.

Fabrication of an acrylic splint may help in re-establishing the transverse width of the palate.

In cases of gross comminution with partial dentition, palatal splints are helpful. Splints are fabricated on casts on which model surgery has been performed. They are designed such that they cover the occlusal surfaces and heights of contour, and care should be taken as to not disturb the soft tissues. Holes placed in the occlusal surfaces in the splint aid in separately ligating it to the arch bar [21]. In case of edentulous patients, Gunning splints are usually used.

#### **55.8 Special Considerations**

#### **55.8.1 Maxillary Fractures in Geriatric Patients**

Advanced age and compromised medical ftness may increase the morbidity associated with surgical management of maxillary fractures. Loss of teeth leading to reduced alveolar bone, reduced vascularity of maxilla and greater pneumatisation of the maxillary sinuses, should be taken into consideration before attempting an open reduction and internal fxation. Modifcation of existing dentures or Gunning splints are viable options in this population.

#### **55.8.2 Maxillary Fractures in Children**

The long-term effects of maxillary fractures on skeletal growth are inconclusive at present. Mobile-displaced maxillary fractures in paediatric patients warrant open reduction and fxation. Removal of hardware in growing patients may be considered to overcome complications of plate translocation (shifting of the position of metal plate due to appositional bone growth), extrusion and possible growth restriction. Resorbable plating systems may offer a solution to overcome such complications.

#### **55.8.3 Haemorrhage Control in Maxillary Fractures**

Branches of the internal maxillary artery provide much of the vascular supply to the midface. In patients with epistaxis or bleeding, ligation of this artery may be necessary. Due to anastomoses from other branches of the internal and external carotid circulation, vascular insuffciency of the maxilla is unlikely even after ligature of maxillary artery. In certain conditions of intractable bleeding not amenable to control by normal packing methods, embolization methods have been used effectively.

#### **55.9 Recent Advances**

The use of pre-surgical stereolithographic models helps in plate contouring and precise positioning of fractured segments. Facilitation of the intraoperative three-dimensional bone positioning is possible due to development of sophisticated computed tomography, computer graphics hardware and image processing software capable of reproducing anatomic templates. Automated preoperative "mirroring" of the contralateral uninjured orbito-zygomaticomaxillary complex to the affected side can result in improved results. The use of intraoperative surgical navigation systems along with mobile cone beam CT improves intraoperative quality control. Endoscopic midface fracture management facilitates smaller incisions, reduced recovery time and minimal post-operative complications. These developments are discussed in the Chap. 41.

#### **55.10 Conclusion**

Maxillary fractures can sometimes occur with signifcant cosmetic and functional implications. Accurate diagnosis and early surgical intervention is essential for successful management of these fractures. The surgeon should keep in mind that the surgical management of maxillary fractures primarily aims at restoration of the vertical and horizontal support buttresses.

**55.11 Case Scenario - A case of maxillary Lefort I fracture where bone grafting was done** (Fig. 55.26a–g)

**Fig. 55.26** Case scenario (fracture maxilla fxation done with grafting in the anterior maxillary sinus wall). (**a**) 43-year-old man sustained bone deep laceration on face causing Le Fort I like fracture pattern. In the emergency department, oral intubation was required due to heavy bleeding. Nasal packs were placed, and the wound was primarily tacked as adjunct measures. (**b**) MIP view of CT scan showing the maxillary segment displaced downwards will loss of anterior maxillary wall height. (**c**) Intraoperative view showing the severely displaced maxillary segment. Access for the fxation was via the existing laceration. A maxillary vestibular incision was not placed. (**d**) The paranasal buttress was maintained, but loss of bone structure seen at the anterior wall sinus region. To attain primary healing and to avoid malunion, iliac crest bone grafts were procured and split into separate pieces. (**e**) (Right side maxilla) the green arrows point to the graft segments. Initially the graft segment was fxed with wire (blue arrow) and was attached to the titanium plate with screws (the plate was spanned from the zygomatic body to the displaced main fracture segment). (**f**) Similar technique done on left side. (**g**) Immediate post-operative view after closure of the laceration. Patient had arch bars fxed and underwent a period of intermaxillary fxation to help in primary union. Post-operative review showed good stability for maxilla and the occlusion was maintained

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 55.26** (continued)

#### **References**


patterns, and treatment with rigid internal fxation. Plast Reconstr Surg. 1998;101(2):319–32.


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## **Fractures of the Zygomaticomaxillary Complex**

Elavenil Panneerselvam, Poornima Ravi, and B. Sasikala

#### **56.1 Introduction**

The zygomaticomaxillary complex (ZMC) refers to the skeletal unit [1] formed by the zygomatic bone and maxilla (Fig. 56.1). These two bones are referred to as a complex, because of the structural and functional relationship between them; they articulate with each other over a wider area, and any traumatic impact on one bone generally infuences the other. This duo complex also constitutes a major part of the orbit, spanning the infra-orbital rim, lateral wall, and foor. Hence the ZMC is also termed *orbitozygomaticomaxillary complex* [2]. Because of its multiple articulations, various names are commonly used to describe ZMC fractures such as "tripod, tetrapod, or pentapod" [3, 4] fractures.

Fractures of the ZMC commonly result in severe cosmetic and functional defcits because of the prominent anatomical position of the zygoma and its proximity to adjacent vital structures such as the globe. Precise reduction and fxation of these fractures is challenging due to their complex anatomic form, multiple articulations, and deformation in multiple planes. The scope of this chapter encompasses the biodynamics of ZMC fractures, clinical implications, and guidelines for successful management.

**Disclosure:** Authors have no fnancial conficts to disclose.

E. Panneerselvam (\*)

Department of Oral and Maxillofacial Surgery,

SRM Dental College, Ramapuram, Chennai, Tamil Nadu, India

Department of Orbit and Oculoplasty, Aravind Eye Hospital, Chennai, Tamil Nadu, India

P. Ravi · B. Sasikala

#### **56.2 Surgical Anatomy**

The term zygoma denotes a "yoke or bar," in Greek. Quite aptly, the zygoma extends as a prominent, sturdy bar across the face, contributing to its transverse width and anteroposterior projection. The clinical signifcance of this bony complex is attributed to its role in defning facial esthetics and globe function.

#### **56.2.1 Articulations**

The zygoma articulates with four bones [5]; superiorly frontal, medially maxilla, laterally temporal bone, and posteriorly sphenoid, through fve processes [4] (Fig. 56.1), namely, the zygomaticotemporal (ZT), zygomaticomaxillary (ZM), infra-orbital (IOR), fronto-zygomatic (FZ), and sphenozygomatic (SZ) or zygomaticosphenoid (ZS). These processes are clinically signifcant in establishing the three-dimensional structural integrity of the upper lateral face.

Fractures of the ZMC have been traditionally called the "tripod or trimalar fractures" because it involved separation at the three processes of the zygoma—the FZ, IOR, and the ZM processes (Fig. 56.2a). The terminology was later modifed to "quadripod or quadramalar fracture" to include separation at the fourth point of articulation, the ZT process (Fig. 56.2b). However, the importance of SZ articulation along the lateral wall of the orbit has been recognized lately, and, hence, ZMC fracture is currently called a pentapod fracture (Fig. 56.2c), to emphasize the necessity of restoring the fve articulations during fracture management.

#### **56.2.2 Relations**

• Zygoma and orbit: ZMC forms the lateral and inferior part of the orbit, protecting as well as supporting the globe and associated soft tissues. The Whitnall's tubercle present on the zygoma (inferior to the FZ suture) provides

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_56) contains supplementary material, which is available to authorized users.

Department of Oral and Maxillofacial Surgery, SRM Dental College, Ramapuram, Chennai, Tamil Nadu, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1151

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_56

attachment to the suspensory ligament of Lockwood that maintains the horizontal axis of the globe [6] (Fig. 56.3a). A fracture line located above the Whitnall's tubercle leads to inferior displacement of zygoma as well as the lateral attachment of Lockwood ligament resulting in antimongoloid slant to the eye (Fig. 56.3b). Thus ZMC fractures greatly infuence the structure and function of the orbit. Further, the contents of the orbit including the globe, extraocular muscles, and orbital fat are intimately

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**Fig. 56.1** ZMC skeletal unit. Articulations of zygoma with facial skeleton and articulating processes

related to the zygoma and may be affected in fractures of the ZMC or its surgical manipulation.


#### **56.2.3 Muscle and Fascia Attachments**

The muscles attached to ZMC are the zygomaticus major, zygomaticus minor, orbicularis oculi, and masseter [9]. Masseter is attached to the zygomatic arch on the lateral and inferior aspect as well as the zygomatic tuberosity (Fig. 56.4a). The downward displacing forces of the masseter have been considered by many as the principal cause of post-reduction instability [10].

The temporal fascia attached to the arch superiorly plays a major role in resisting the downward displacement of fractured ZMC or arch due to the inferior pull of the masseter (Fig. 56.4b) [1].

#### **56.2.4 Zygomatic Arch**

The arch is the key parameter for re-establishing the sagittal projection as well as transverse width of the face [11]. An arch which is bent outward or inward gets shortened [4]. This leads to retrodisplacement of zygoma resulting in altered facial width (Fig. 56.5b). It is important to remember

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**Fig. 56.2** Types of ZMC fractures. (**a**) Tripod fracture. (**b**) Tetrapod fracture. (**c**) Pentapod fracture

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**Fig. 56.3** Relation of suspensory ligament to zygoma. (**a**) Displacement of suspensory ligament of Lockwood leading to anti-mongoloid slant. (**b**) Clinical appearance of anti-mongoloid slant

that in spite of being referred to as an arch, it does not have an exaggerated curvature. Therefore, overzealous contouring during reduction of zygomatic arch fractures can result in compromised esthetics. The arch is encased by a thick periosteal and fascial envelope which counteracts the displacing forces of the masseter [1]. However, when the periosteal envelope is damaged due to high-velocity injuries, the fracture segments show more displacement.

#### **56.2.5 Nerves and Blood Vessels**

The nerves in close proximity to the ZMC are (1) infraorbital nerve and (2) zygomatic nerve [12] (Fig. 56.6a). The infra-orbital nerve runs along the ION groove and enters the

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**Fig. 56.4** Displacing forces acting on the zygoma and arch. (**a**) Masseter exerting downward force. (**b**) Temporalis with a superior vector

ION canal giving off the superior dental plexus of nerves before exiting through the ION foramen onto the face. Here it innervates the lower eyelid, lateral aspect of the nose, and upper lip of the ipsilateral side. The zygomatic nerve which enters the orbit through the inferior orbital fssure divides into two branches, the zygomatico-facial and zygomaticotemporal which emerge onto the face through their respective foramina. The zygomaticofacial nerve innervates the skin over the malar area, while the zygomaticotemporal nerve supplies the skin over the anterior temporal region. These nerves may be injured due to trauma or during surgery. The severity of paresthesia which arises is generally proportional to the degree of displacement of a fractured zygoma [13]. The other nerves whose function may be affected in ZMC fractures are the optic nerve [14] and facial nerve [15]. Blood vessels of importance related to the ZMC are infraorbital artery and vein [16] (Fig. 56.6b) which accompany the infra-orbital nerve. Uncontrolled forces delivered during elevation of zygoma may injure these vessels resulting in severe intra-op bleeding.

#### **56.3 Classifcation**

#### **56.3.1 Classifcation of ZMC Fractures**

Numerous classifcations have been proposed for ZMC fractures; this chapter would discuss the most practical ones which help in understanding the biodynamics of fracture as well as facilitate quick decision-making regarding the treatment.

• The classifcation proposed by Rowe and Williams [1] (Fig. 56.7) is based on the axis of rotation of ZMC and the

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**Fig. 56.5** Change in facial dimension in zygomatic arch fractures. (**a**) Inward bowing of arch. (**b**) Outward bowing of arch

stability after reduction. Following trauma, the zygoma may undergo rotation along two axes: vertical axis extending through the FZ suture and frst molar and horizontal axis running across the infra-orbital foramen and zygomatic arch. According to this classifcation, fractures were considered as *stable after elevation* when they demonstrated (1) arch only fracture with medial displacement and (2) rotation around vertical axis (medially/laterally), while fractures were categorized as *unstable after reduction* when the following features were observed: (1) arch only fracture with inferior displacement (Fig. 56.8), (2) ZMC fracture rotated around horizontal axis (Fig. 56.7), (3) dislocated en bloc (inferiorly/laterally/medially) (Fig. 56.9a), and (4) comminuted (Fig. 56.9b).

This classifcation provides clinical guidance regarding the stability of fracture after reduction and the necessity for fxation.


ture, and types A2 and A3 are separation at the FZ suture and IOR, respectively. Type B is a complete monofragment type with separation at all fve sites of articulation and type C which is multifragmented.

A special and rare variant of zygoma injuries includes *avulsion* of zygoma [18] (Fig. 56.11). These injuries result from tangentially directed forces with high velocity or greater energy. The fractured zygomatic fragment characteristically becomes a non-vascularized-free graft whose management is complex.

#### **56.3.2 Classifcation of Arch Fractures**

The fractures involving the zygomatic arch constitute a separate entity.

The various patterns of zygomatic arch fractures have been described by **Ozyazgan et al.** [19] (Fig. 56.12) based on the number of fracture lines and displacement of fracture fragments:


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**Fig. 56.6 a**, **b** Neurovascular structures related to ZMC fractures. OA, ophthalmic artery; nb, nasal branch; zmb, zygomatico-malar branch; vb, vestibular branch

and plural fracture (type II B). Plural fractures are termed type II B-R when they are approximated or reduced and type II B-D, when displaced.

**Yamamoto et al**. classifcation [20] (Fig. 56.13) differentiates fractures based on displacement: type I, no displacement; type II, displacement with bone contact at all fracture lines; type III, displacement without bone contact at one fracture line; type IV, displacement without bone contact at two fracture lines; and type V, comminution or displacement without bone contact at three or more fracture lines. **Honig Merten et al**. [21] (H-M classifcation) (Fig. 56.14) classifed zygomatic arch fractures based on CT fndings as class I which indicated isolated tripod fracture, class II as an isolated stick fracture of the arch, and class III a combined fracture of the malar bone and the zygomatic arch.

#### **56.4 Clinical Assessment**

The clinical assessment of ZMC fractures is performed by a thorough examination of the face and the eye. As the zygoma forms an integral part of the orbit (foor and lateral wall), any trauma to the ZMC may have profound impact on the integrity of the globe and vision [2, 22]. This mandates a primary ophthalmic examination prior to facial examination.

#### **56.4.1 Examination of the Eye**

The globe is meticulously assessed for its form, position, and function. This is performed by a comprehensive examination protocol called "8-point eye exam" [23] provided by the American Academy of Ophthalmology (refer to Chap. 57).

#### **56.4.2 Examination of the Face**

The facial examination should focus on assessment of (1) facial symmetry and morphology and (2) functions such as mouth opening, vision, sensory perception, and occlusion.

The clinical characteristics of ZMC fractures [1, 4, 5] may be divided based on their cosmetic and functional implications (Box 56.1) .


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**Fig. 56.7** Axes of rotation of ZMC fractures

A description of clinical features with their associated pathophysiology is provided below.


fractures does not have a posterior limit in contrast to SCH due to globe injuries [24]. It is important to note that SCH without a posterior limit is also seen in skull base fractures [25].Chemosis and hyphema are also seen in some cases.


from behind the patient to detect malar depression. However, the fattening cannot be appreciated in the presence of moderate or severe edema.

• *Eye signs:* The eye signs are a very striking feature of zygomatic injury especially when rotated and inferiorly displaced. Inferior displacement of zygoma results in hypoglobus and an anti-mongoloid slant to the eye (Fig. 56.3b). Inferior or posterior displacement of the infra-orbital rim also causes lowering of the lower eyelid leading to increased scleral show (Fig. 56.17).

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**Fig. 56.8** Inferior displacement of zygomatic arch

The commonly observed variations in globe position are exophthalmos in posteriorly/medially displaced zygoma (Fig. 56.18a−c) and enophthalmos in laterally and inferiorly displaced zygoma (Fig. 56.19). En/exophthalmos resulting from ZMC fractures must be differentiated from enophthalmos arising from blow-out fractures involving the orbital foor. The clinical implications of the above are explained under "preoperative planning." Also, it is important to remember that the traditional assessment of en/exophthalmos by Hertel's exophthalmometer does not refect the true position of the globe in displaced ZMC fractures because it uses the orbital rim as a point of reference. Naugle's which utilizes supraorbital rim as a reference is ideal in such cases [26]. However CT evaluation is the most preferred modality [27] (refer Chap. 57 on orbital fractures).


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**Fig. 56.9** En bloc and comminuted ZMC fractures. (**a**) En bloc displacement of the right ZMC. (**b**) Comminuted ZMC of left side

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**Fig. 56.10** Zing's classifcation of ZMC fractures. (**a**) arch only (Type A1), (**b**) separation at fronto-zygomatic suture (Type A2), (**c**) separation at infra-orbital rim (Type A3), (**d**) complete mono-fragment (Type B) and (**e**) multi-fragment (Type C)

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**Fig. 56.11** Avulsion of zygoma

• *Paresthesia:* Infra-orbital nerve being closely related to the zygoma gets compressed or pulled in displaced or comminuted ZMC fractures leading to paresthesia along the lower eyelid, upper lip, and lateral aspect of the nose. Occasionally, a patient may also have altered sensation involving the maxillary teeth leading to a perception of altered dental occlusion [5]. The other theory put forward for altered occlusion is the fexing of the ipsilateral maxillary alveolus leading to premature molar contact [31]. Paresthesia involving the zygomaticofacial and zygomaticotemporal nerves may be present. In rare occurrences, injury to the facial nerve leading to paresis has been observed in severely displaced or high-velocity injuries of the zygoma [15].

• *Altered/loss of vision:* Binocular diplopia is a common fnding. The diplopia that develops following trauma can be the result of soft tissue (muscle or periorbital) entrapment, neuromuscular injury, intra-orbital or intramuscular hematoma/edema, or a change in orbital shape, with displacement of the globe [32]. A forced duction test (FDT) (Fig. 56.21) would confrm any physical impediment to ocular motility [4]. Diplopia due to edema/hematoma resolves in a few days, while that due to muscle entrapment does not, necessitating surgical correction.

Another rare but serious sequel to ZMC fractures is traumatic optic neuropathy which may present as total or partial loss of vision [33].

#### **56.5 Imaging for ZMC Fractures**

Radiological assessment is essential for accurate diagnosis and assessment of severity of the fracture.

**Fig. 56.12** Ozyazgan et al. classifcation of zygomatic arch fractures

• *Plain radiographs* [31]*:* Conventional radiographs continue to remain the mainstay of imaging at some centers. Conventional radiographs may also be useful in the postoperative phase, to assess fracture reduction. However conventional radiographs are limited by superimposition of structures.

The commonly used views include the waters view (37° occipitomental) (Fig. 56.22) which provides good visualization of the fractured zygoma and helps in comparing with the contralateral side. Tracing the McGrigor-Campbell lines [34] (refer Chap. 55) or the Dolan's lines [35] are useful in identifcation of fractures on the Water's view (Box 56.2).

**Box 56.2 (Fig. 56.22): Radiographic Appearance in ZMC Fracture**


**Fig. 56.13** Yamamoto et al. classifcation of zygomatic arch fractures

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**Fig. 56.14** Hönig Merten (HM) et al. classifcation of zygomatic arch fractures

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**Fig. 56.15** Periorbital edema, ecchymosis, and subconjunctival hemorrhage

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**Fig. 56.16** Loss of facial prominence in right malar region

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**Fig. 56.17** Increased scleral show on right side

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**Fig. 56.18** Exophthalmos. (**a**) Frontal view demonstrating exophthalmos and hyperglobus on right side. (**b**) Basal view of the same patient showing exophthalmos on right side. (**c**) Axial CT section demonstrating exophthalmos of the right eye

• The submentovertex/jug handle view [31] (Fig. 56.23) offers the best representation of fractures of the arch. Loss of elephant trunk appearance which is indicative of arch fracture is well appreciated in this view.

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**Fig. 56.19** Enophthalmos. (**a**) Frontal view showing enophthalmos on left side. (**b**) Basal view of the same patient showing enophthalmos on left side. (**c**) Axial CT section demonstrating enophthalmos of the left eye


The role of intra-operative imaging is discussed in the later segments of the chapter.

#### 56 Fractures of the Zygomaticomaxillary Complex

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**Fig. 56.20** Restricted mouth opening in ZMC fractures. (**a**) Retrodisplaced zygoma impinging on the coronoid. Yellow arrow demonstrating restriction of space between the body of zygoma and coro-

noid. Process, blue arrow demonstrating normal space. (**b**) Fractured arch impinging on the coronoid (Here, blue arrow demonstrates reduced space)

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**Fig. 56.21** Forced duction test

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**Fig. 56.22** Waters view with Dolan's lines. (**A**) Orbital line, (**B**) Zygomatic line and (**C**) Maxillary line. The yellow arrows indicate fracture separations noted on the right ZMC

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**Fig. 56.23** Submentovertex view demonstrating fractured arch on left side

#### **56.6 Principles of Management**

#### **56.6.1 Indications and Contraindications for Intervention** [5, 37]

Surgical outcome of ZMC fractures is greatly infuenced by two important factors: (1) choosing the right indications for intervention and (2) ideal time for surgery. Not all fractures of the ZMC require surgical intervention. The decision to intervene should be based on signs and symptoms and presence of functional impairment (Fig. 56.26).


#### **56.6.2 Timing of Intervention** [39]

ZMC fractures are not emergencies, and treatment can be delayed, if necessary.


#### **56.6.3 Surgical Objectives**

Management of ZMC fractures is aimed at achieving the surgical objectives highlighted in Box 56.3 [37].

#### **Box 56.3: Surgical Objectives in ZMC Fracture**


#### **56.6.4 Need for Prophylactic Antibiotics**

ZMC fractures may be categorized into three classes based on their propensity to develop postsurgical infection: clean fractures (isolated arch fractures), clean-contaminated (ZMC fractures compound into the antrum), and dirty (fracture which is open to exterior). While type three fractures require regular antibiotic prophylaxis, types 1 and 2 show minimal rates of infection and may either need "no" antibiotic prophylaxis [40] or a modifed single-day postsurgical regimen [41].

#### **56.7 Preoperative Planning** [42]

ZMC fractures show high propensity for over or under reductions due to lack of objective intra-operative measures to assess reduction. This may be overcome with accurate pre-

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**Fig. 56.24** CT scan of patient with left ZMC fracture. (**a**) Axial view demonstrating overriding of fracture fragments at SZ suture. (**b**) Axial section demonstrating fracture at the IOR and buckling of arch. (**c**) Coronal section showing separation at the FZ and ZM sutures with medial displacement of the body of zygoma. (**d**) Sagittal section demonstrating posterior displacement of IOR and large blow-out fracture of orbital foor

operative planning which helps in realizing surgical objectives in a predictable manner.

Preoperative planning includes three vital steps:


#### **56.7.1 CT Evaluation**

Proper CT evaluation is absolutely essential for choosing the ideal treatment; CT plays a very important role in differentiating en/exophthalmos due to ZMC fractures from those due to orbital fractures. This helps in arriving at a decision regarding internal orbit reconstruction (Box 56.4).

#### **Box 56.4: Relative vs. Absolute En/Exophthalmos**


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**Fig. 56.25** CT with 3D volume rendering demonstrating medially rotated right ZMC fracture

#### **56.7.2 Model Surgery**

The process begins with obtaining CT scans of the patient with minimum slice thickness of 0.6 mm. This is followed by two different sequences of workfow (Fig. 56.27) which are described below.

#### (A) **Planning Using Physical Models**

The frst step involves generation of a physical stereolithographic model (STL) from the CT scan of the patient. There are two methods by which this can be done.

1. **STL model with the actual deformity:** This model presents the post-traumatic deformity, as observed clinically. A routine model surgery is then performed, by which the displaced fragments are cut and repositioned to obtain optimal anatomical form.

The repositioned fragments are stabilized temporarily with wax. The fxation devices (miniplates) are then pre-contoured over the model. Such precontoured implants are used to guide intra-operative fracture reduction as well as fxation. Figure 56.28a−d demonstrates the sequence described.

2. **STL model after mirroring:** CT scan is used to generate a virtual model wherein the normal side is mirrored onto the fractured side. The virtual model is used to print a physical model which demonstrates the skull which is bilaterally symmetrical, mimicking ideal reduction status. Similar to the earlier method, implants for fxation are pre-contoured over this model to help achieve optimal results intra-operatively. Figure 56.29a−d demonstrates a similar clinical scenario.

#### (B) **Planning Using Virtual Models**

This method utilizes the complete spectrum of computerassisted surgical planning. A CT scan is obtained to create a virtual model on which the entire surgical sequence of reduction is performed and on which the stents for intraoperative guidance are designed. Intra-operative stents are printed from these virtual designs. There is no physical "handheld" model here (Refer Chap. 41).


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**Fig. 56.28** Model surgery for pre-contouring of implants. (**a**) CT image demonstrating fractured ZMC of right side. (**b**) STL model demonstrating deformity. (**c**) Repositioning of fracture fragments to anatomical position. (**d**) Pre-contouring of implants

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**Fig. 56.29** Use of mirrored models for pre-contouring of implants. (**a**) 3D CT image of fracture. (**b**) Mirroring of zygoma of normal side to fractured side. (**d**) Generation of mirrored STL model and pre-contouring of implants

#### **56.7.3 Soft Tissue Analysis**

Li et al. [44] have described a technique for 3D simulation and prediction of soft tissue—outcome analysis in ZMC fractures. This process enables prediction of postoperative soft tissue changes in patients with ZMC fractures who are indicated for primary/secondary surgical interventions. The planning involves utilization of CT data and 3D stereophotography for the analysis. The technique may also be utilized for evaluation of postsurgical results.

#### **56.8 Reduction of ZMC Fractures**

Reduction of zygoma is unique in two aspects:


Fracture reduction may be done either by direct or indirect method, and the approaches may be extraoral or intraoral [1].

#### **56.8.1 Direct vs. Indirect Method**

The indirect method is a blind technique where fracture is reduced without exposure of the fracture site (e.g., Gillies reduction), while direct method involves reduction of the fracture under direct visualization (e.g., coronal approach to reduce arch fracture). The differences between the two methods are shown in Fig. 56.30. However, indirect method is more commonly practiced. Open method is resorted to when the ZMC fracture is (1) severely displaced, (2) complex or comminuted, (3) when stable reduction is doubtful, and (4) there is a need for internal orbit reconstruction. However, no "single technique" is superior, and sometimes, a combination of techniques is more effective.

The extraoral reduction techniques may be either percutaneous, temporal, or endoscopic [1, 45].

• *Temporal approach* [46], commonly called the Gillie's (Figs. 56.31a−f and 56.32a), is the most popular method of ZMC reduction. This approach is favored because the incision is placed within the hairline which does not leave a visible scar. It also offers a very predictable force during reduction and may be used for reduction of both the arch as well as the zygoma. The technique is based on the anatomical basis that the plane between the temporalis fascia and the temporalis muscle offers direct access to the zygomatic arch and zygoma. The only contraindication to this approach is the presence of concomitant temporal bone fracture. The incision is placed at a level 2 cm above the helix of the ear, paralleling the anterior branch of the superfcial temporal artery, well within the hairline (Fig. 56.33). Dissection is carried down through the skin, subcutaneous tissue, and galea aponeurotica (temporoparietal fascia—TPF) to reach the temporalis fascia.


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**Fig. 56.31** Gillies temporal approach. (**a**) Marking of incision parallel to frontal branch of superfcial temporal artery. (**b**) Placement of incision. (**c**) Exposure of deep temporal fascia. (**d**) Incision through deep

An incision is made through the temporalis fascia to reveal the underlying temporalis muscle. A Howarth's elevator is inserted between the temporalis fascia and the muscle, to create a plane for the zygomatic elevator. Two types of zygomatic elevators, namely, the Bristow's and Rowe's (Fig. 56.34a), are commonly used; the Bristow' s has a single fat and elongated working tip attached to a handle and is used like a spatula for elevation, while the Rowe's elevator has an additional arm attached to the working tip which serves two purposes: (1) to provide the necessary countertraction during elevation so that it relieves the fulcrum off the temporal bone and (2) to evaluate the approximate depth of insertion of the working tip when inserted into the tissue. The zygomatic elevator is positioned in the plane created, directed inferiorly to reach the deeper surface of the zygoma and carefully elevated, while an ironing motion is used to smoothen the temporal fascia exposing temporalis muscle. (**e**) Developing plane of elevation with periosteal elevator. (**f**) Placement of Rowe's zygomatic elevator for elevation

collapsed arch form. Care is taken not to lever the elevator against the skull (Video 56.1).

#### *Clinical Tip*


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**Fig. 56.32** Different approaches for reduction of fractured ZMC. (**a**) Gillie's. (**b**) Poswillo. (**c**) Dingman. (**d**) Balasubramaniam. (**e**) Quinn


This technique is performed through a standard lateral brow approach where the fracture is visualized by a direct approach to the bone after incising through the skin, subcutaneous tissue, and periosteum. An elevator is then passed laterally and posterior to the orbital rim into the temporal fossa. The temporal aponeurosis (attachment of the deep temporal fascia to the lateral orbital rim) is incised, and the elevator is passed beneath it to lift the arch or the body of the zygoma in an upward, forward, and outward fashion. The original description by Dingman utilized trans-osseous wiring for stabilization of the front-zygomatic suture. However current methods incorporate the use of miniplate osteosynthesis through this approach.

#### **56.8.3 Intraoral Techniques**

The greatest advantage of intraoral techniques is "no skin incision." Commonly followed methods are:

• *Balasubramaniam's/Keen's approach* (upper buccal sulcus approach) [50] (Fig. 56.32d)

This approach uses a vestibular incision behind the zygomatic buttress. A Howarth's periosteal elevator is inserted in a supraperiosteal plane to engage the infratemporal surface of the zygoma. Reduction is achieved with an upward, forward, and outwardly directed force. When greater force is needed to elevate as in impacted zygomas

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**Fig. 56.33** Gillie's correct plane for elevation. It is important to understand that the deep temporal fascia divides into two, to enclose the zygomatic arch and the fat above, approximately 2 cm above the arch. An incision placed too low may mislead the young surgeon into the fat plane (b, lateral to the arch) rather than the subfascial plane (a, medial to the arch) (Also refer Fig. 85.1a)

or delayed presentation, a Bristow's/Rowe's zygomatic elevator (Fig. 56.36) or the arm of an upper anterior forceps may be used. The technique offers more mechanical advantage than the extraoral method; less force is needed to elevate, because the force is directed entirely at the center of the zygomatic body, which is considered more effective.

• *Quinn's procedure* (lateral coronoid approach) [51] (Fig. 56.32e) employs an incision over the anterior border of the ramus. An elevator is inserted in a supraperiosteal plane, lateral to the coronoid process and paralleling the temporalis tendon to reach the medial surface of the zygomatic arch. Elevation of the arch may be done in an ironing fashion.

Both the abovementioned intraoral techniques are supraperiosteal methods.

#### **56.8.4 Reduction of Zygomatic Arch**

Elevation of the depressed arch is usually performed in an indirect manner, using the Gillie's technique. However numerous techniques have been advocated in literature. These include the "roller-coaster" lateral brow technique [52] and methods using percutaneous towel clip [53], traction suture [54], Foley's catheter [55], K wire [56], and Dingman elevator [57] to restitute the arch anatomy.

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**Fig. 56.34** Instruments for reduction. (**a**) Rowe's . (**b**) Poswillo hook. (**c**) Universal bone reduction screw

#### **56.8.5 Intra-operative Assessment of Reduction**

The intra-operative assessment of reduction is a critical step in zygoma management, especially in closed reduction. The methods commonly used are (1) clinical assessment, (2) imaging, and (3) use of prefabricated guides/stents.


**Box 56.5: Indicators of Accurate Reduction of ZMC #** Reduction along the vertical axis—SZ suture Reduction along the horizontal axis—ZM suture

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**Fig. 56.35** Percutaneous reduction with Poswillo's technique. (**a**) Marking on skin. (**b**) Percutaneous insertion of bone hook

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**Fig. 56.36** Balasubramaniam's technique

#### **56.8.6 Precautions During and After Reduction**

Manipulation of zygoma during reduction has been known to cause certain complications such as bleeding from infra-orbital vessels [16]. Use of controlled force during indirect reduction greatly reduces such complications. It is prudent to watch out for stimulation of Oculocardiac refex (OCR) [63] as described later in the text. OCR may also be prevented by administering regional blocks before elevation [64].

Once the reduction is completed and found satisfactory, the fracture fragments need to be maintained in the reduced state. A Zimmer splint [65] (preformed aluminum splint with foam on the undersurface) may be adapted to the reduced arch and secured with sutures. It is maintained in situ for 2–3 weeks.

Finally, it is mandatory to do a force duction test (FDT) after elevation of zygoma [5] (Box 56.6).

#### **Box 56.6: FDT Is Mandatory After Reduction of ZMC Fractures** (Fig. 56.21)

During reduction of ZMC fractures, as the fractured bones get realigned to normal anatomical position, entrapment of surrounding soft tissue or muscles may occur between the fragments

This may lead to port-surgical diplopia, necessitating a surgical revisit.

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**Fig. 56.37** Intra-operative assessment of reduction using C-arm. (**a**) Intra-operative positioning of C-arm. (**b**) Image demonstrating zygomatic arch after reduction

#### **56.9 Fixation and Stabilization of ZMC Fractures**

#### **56.9.1 Need for Fixation**

Fixation needs of ZMC fractures depend on the postreduction stability. Classifcation of fracture patterns by Rowe and Williams [1] provides guidance on assessment of fracture stability after reduction. Any fracture classifed as stable after reduction does not require fxation, while those considered unstable, mandate fxation. However, a practical method would be to apply moderate digital pressure on the malar eminence after reduction. Displacement secondary to this maneuver, requires fxation [59]. The algorithm proposed by Rodrigo and Belini et al. is also a practical guide to manage ZMC fractures which are not associated with orbital component [3]. For ZMC fractures with orbital involvement, Ellis and Perez advocate guidelines for orbital reconstruction based on CT evaluation. Most of the studies indicate increase of fxation points from 1 to 2, 3, and 4 points based on the status of intraoperative stability after reduction. Involvement of orbit leading to changes in intra-orbital volume requires orbital reconstruction [59].

**Box 56.7: Ideal Sequence of Fixation**


#### **56.9.2 Fixation Principles**

The current dictum is "any zygoma which when fractured and displaced must be fxed" [37]. The objectives are to achieve a 3D reconstruction (transverse width, vertical height, and anteroposterior projection) and establish the buttresses. Attention needs to be given to the order of restoration [66, 67]. The results of various biomechanical experiments indicate that the vertical buttress needs to be fxed frst, to restore the facial height. Then, the anteroposterior projection may be achieved by restoring the arch (Box 56.7).

#### **56.9.3 Surgical Access to Fixation**

Surgical approaches for ZMC fxation are chosen based on the fracture pattern and fxation needs. A single or multiple incision may be used for the surgical exposure of ZMC fractures [30, 68, 69].

The incisions may be broadly classifed as:


The list of incisions and the exposure achieved (green shaded areas on Fig. 56.38) by each are highlighted in Box 56.8 (Fig. 56.38)

The following is a description of the various incisions used to access the fxation points in ZMC fractures. It is important to take adequate measures for globe protection while placing any periorbital incisions [70]. The commonly followed methods include either a temporary tarsorrhaphy (Fig. 56.39) or a corneal shield (Fig. 56.40). The tarsorrhaphy also offers the additional advantage of being used as a retraction suture during surgery.

#### **Box 56.8: Approaches to ZMC Fractures**


## **56.9.3.1 Supraorbital/Lateral Brow Incision**

#### (Fig. 56.38)

The lateral brow incision is otherwise called as "in the brow" incision and offers a fast and direct access to the frontozygomatic suture and lateral part of the supraorbital rim. The extensions for the incision must be well within the eyebrow which provides an ideal camoufage (Fig. 56.41a). However, this incision may not be ideal in people who are cosmetically inclined to maintain a higher eyebrow. Absence of any important neurovascular structures in this area makes this incision easy to perform, even by beginners.

After infltration of LA solution containing vasoconstrictor, a 2 cm long incision is placed along the curve of the

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**Fig. 56.38** Incisions to access ZMC fractures

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**Fig. 56.39** Tarsorrhaphy

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**Fig. 56.41** Periorbital incisions for FZ suture. (a) Lateral brow incision. (b) Lateral brow extension (shown in dotted lines). (c) Upper lid blepharoplasty

superolateral part of the orbital rim. Care is taken to incline the blade parallel to the hair so that the shafts are not transected. Failure to do so may cause linear alopecia along the incision line, which may be unaesthetic. Incision is carried through the skin, subcutaneous tissue, and the orbicularis oculi muscle. The fap is undermined in the supraperiosteal plane to permit ease of retraction. A periosteal incision is then placed above the fronto-zygomatic suture for reduction and fxation (Fig. 56.42a, b).

When additional exposure is needed on the medial aspect, the incision is extended up to the supraorbital nerve. For additional inferior extension, a gradual 90° turn into the

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#### **Fig. 56.40** Corneal shield

crow's feet wrinkle which is restricted to the skin only, is utilized to provide a much wider access [70] (Fig. 56.41b). This extension must remain 6 mm superior to the lateral canthus. Inferior limit of the incision along the lateral orbital rim should not cross the RSTL (resting skin tension lines) to avoid unaesthetic scars.

Closure is performed in layers with approximation of the periosteum and subcutaneous tissues (Video 56.2).

#### **56.9.3.2 Upper Eyelid Blepharoplasty Incision**  (Fig. 56.38)

The upper lid blepharoplasty incision is otherwise called as the *supratarsal fold* or *upper eyelid crease* incision. It offers the most esthetically favorable approach to the frontozygomatic suture region. The incision is made along the eyelid crease, 10 mm above the free margin of the eyelid (Fig. 56.41c). As the incision extends laterally, it should be at least 6 mm above the lateral canthus. When eyelid anatomy is distorted with edema or hematoma, the contralateral lid crease measurements are used to mark the incision.

The incision is placed through the skin and muscle and is raised as a skin-muscle fap for good viability of the overlying skin. The plane of dissection is below the orbicularis oculi in a superior and lateral fashion to reach the periosteum (Fig. 56.43a, b). The periosteum is sharply incised to expose the bone underneath. Further dissection along the bony margins is strictly subperiosteal; any violation of the periosteum may cause herniation of the lacrimal gland which is present in the superolateral concavity of the orbit. Closure of the incision is done in layers, starting with periosteum, followed by the orbicularis oculi, and the skin.

An important advantage of the upper lid blepharoplasty incision is the extensive access it offers to the entire superolateral aspect of the orbit. It also permits good visualization and access to the spheno-zygomatic suture which is the most important indicator of reduction of ZMC fractures.

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**Fig. 56.42** Lateral brow incision—intra-operative. (**a**) Marking. (**b**) Exposure

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**Fig. 56.43** Upper lid blepharoplasty intra-operative. (**a**) Marking. (**b**) Exposure demonstrating ORIF

#### **56.9.3.3 Subciliary Incision** [71, 72] (Figs. 56.38, 56.44a and 56.45a, b)

The subciliary incision is a commonly used transcutaneous approach which offers good exposure of the infra-orbital rim along with the entire orbital foor. This may be a very useful approach in the management of ZMC fractures which involve the orbital foor also.

The skin incision is placed along the entire length of the lower eyelid, 2 mm below the level of the eye lashes to conceal the future scar.

The incision must not be extended more than 2 cm lateral to the lateral canthal ligament. This prevents any inadvertent damage to the temporal branch of the facial nerve which is present about 3 cm lateral to the lateral canthal ligament.

Once the skin is incised, the dissection may proceed in three different ways [30, 70] (Fig. 56.45b) (Box 56.9):

(i) *"Skin-alone" fap technique* where the plane of dissection is along the *subcutaneous plane between the skin of* 

#### **Box 56.9: Comparison of Variants of Subciliary Incisions**


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**Fig. 56.44** Lower eyelid incisions. (a) Subciliary. (b) Extended subciliary showing area of exposure shaded. (c) Subtarsal incision. (d) Infra orbital

*the eyelid and the orbicularis oculi.* On reaching the facial surface of the infra-orbital rim, the orbicularis muscle along with the periosteum is incised to reach the rim. The periosteal incision is generally placed at least 3–4 mm below the level of the infra-orbital rim (Fig. 56.45a and 56.45b1).


The development of a skin-alone fap at the marginal level and a "skin-muscle" fap at the subtarsal level creates a *step* in the plane of dissection. The dissection then proceeds caudally toward the infra-orbital rim in a submuscular plane superfcial to the orbital septum. On reaching the rim, the periosteum is incised sharply about 3–4 mm below the level of the rim on the facial aspect.

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**Fig. 56.45** Lower eyelid incisions—sagittal view. (a) Subciliary, sub tarsal and infra-orbital (b) Variants of sub-ciliary incision

The incision of the periosteum at this level not only helps preserve the attachment of the orbital septum along the rim margin but also lies above the level of the infra-orbital foramen which is seen about 7–8 mm below the level of the rim. Dissection of the periosteum can be performed along the entire length of the infra-orbital rim, anterior maxilla, and the zygoma to provide excellent exposure.

Advantages of the stepped approach include (1) minimal chances of buttonholing or darkening of the skin due to vascular compromise (2) lesser incidence of ectropion and entropion (3) reduced scarring at the eyelid margins due to preservation of the pre-tarsal orbicularis oculi fbers.

The differences between the three variants of subciliary incision are highlighted in Box 56.9 (Figs. 56.45b).

#### **56.9.3.4 Extended Lateral Exposure with the Subciliary Approach** Fig. 56.46 [70]

After placing a standard subciliary incision, supraperiosteal dissection is performed along the lateral orbital rim in the cephalic direction till the FZ suture or a few millimeters beyond (Figs. 56.44b and 56.46). This releases the skin fap and makes it amenable to easy retraction to reach the FZ region. The periosteum is then divided in the center of the lateral orbital rim along its length. In most cases the lateral canthal ligament may be stripped in a subperiosteal fashion to facilitate comfortable access to the FZ suture. This approach may be used to avoid an additional incision for exposure of the FZ suture.

#### **56.9.3.5 Subtarsal Approach** [73] (Figs. 56.38, 56.44c and 56.47)

Subtarsal or *mid-lid incision* was also described by Converse. The incision is marked 5–7 mm below the inferior lid margin corresponding to the lower border of the tarsal plate, along

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**Fig. 56.46** Subciliary with lateral extension demonstrating exposure of the FZ suture after ORIF

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**Fig. 56.47** Subtarsal marking intra-operative

the subtarsal crease (Fig. 56.47). The lateral extension of the incision may be extended up to 2 cm beyond the lateral canthal ligament similar to the subciliary incision, along one of the resting skin tension lines. The incision is made through the skin and subcutaneous tissue. The *pre-septal fbers of the orbicularis oculi are also divided at the same level*, and the plane of dissection is maintained superfcial to the orbital septum. The dissection is carried out caudally to reach the infraorbital rim, and the periosteum is divided below the level of the rim on the anterior surface of the maxilla and zygoma.

The subtarsal approach is favored more than the subciliary [73] due to its easier technique and lesser incidence of complications (Box 56.10).

#### **Box 56.10: Subtarsal vs. Subciliary Incision**


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**Fig. 56.48** Figure demonstrates use of frost suture for ZMC fracture approached by transconjunctival and upper lid blepharoplasty incision. *Technique for frost suture. A 4-0/5-0 nonabsorbable suture on a 3/8th circle needle is passed to engage the inferior tarsal plate, at the middle of the lower eyelid margin. The suture is taken either through the gray line or through the pre-tarsal skin to include the skin, orbicularis, and the tarsus. Appropriate tension is applied in superior direction by the anchoring the suture ends, to the supraorbital skin, 5 mm above the eyebrow using adhesive tapes*

An important consideration following lower eyelid approaches is the application of the "frost suture" [74] (temporary lower eyelid suspension suture) (Fig. 56.48), to prevent postoperative ectropion. Frost suture also permits visualization of the globe in the postoperative phase, when required (Refer Fig 11.13).

Nevertheless, lower rim incisions are often associated with postoperative ectropion and scleral show. While scleral show/lid traction refers to abnormal exposure of sclera (1 mm or more) with contact between bulbar conjunctiva and the lid, ectropion refers to eyelid eversion with no contact between bulbar conjunctiva and lid [75]. Ectropion requires correction for cosmetic reasons as well as functional problems arising from keratinization of exposed conjunctiva. Treatment varies from conservative modalities to surgical procedures [76, 77] (Box 56.11).

#### **Box 56.11: Measures to Correct Ectropion and Scleral Show**


#### **56.9.3.6 Infra-orbital Incision** (Figs. 56.38 and 56.44d)

This is performed as an incision which simultaneously divides the skin, orbicularis muscle, and periosteum, along infra-orbital rim. Though the infra-orbital incision offers the most direct approach to the infra-orbital rim and orbital foor, it is seldom preferred in contemporary surgery due to the unsightly postoperative scar and prolonged edema of the lower lid region due to disruption of lymphatic drainage.

#### **56.9.3.7 Transconjunctival Incision** [78, 79] (Figs. 56.38 and 56.49)

Transconjunctival incision has gained popularity because it completely negates the unesthetic scarring associated with skin incisions. This incision offers good access to the infraorbital rim and SZ regions with either a pre-septal or retroseptal approach. Refer to the Chap. 57 for a detailed description of the approach. The modifed transconjunctival incision with a cutaneous Y extension when combined with lateral canthotomy offers excellent exposure to the IOR, SZ, as well as the FZ region [80–82]. The complications of transconjunctival incisions include entropion [82], in-curling of lashes (trichiasis) [83], or growth of the eyelashes in two layers (distichiasis) [84]. Malposed lateral canthus has also been observed following improper repositioning of the lateral canthus after canthotomy [82].

#### **56.9.3.8 Vestibular** [85] **Incision** (Figs. 56.50 and 55.16)

The vestibular incision is the most frequently used approach to access the ZM buttress. The popularity is due to its application for reduction of ZMC fracture as well as fxation at the ZM buttress. Refer to the Chap. 55 for description of the technique. The author of this chapter (EP) uses the vestibular approach to also fx the zygomatic arch fractures which override at the zygomaticotemporal suture, with transbuccal instrumentation (transoral arch fxation technique) (Refer to recent trends section 56.16).

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**Fig. 56.50** Vestibular incision demonstrating fracture at ZM buttress

**Fig. 56.49** Transconjunctival intra-operative

#### **56.9.3.9 Preauricular** [86] (Figs. 56.38, 56.51, 53.17a, b and 65.6) (Refer Video on pre auricular approach in Chap. 53)

Preauricular incision is useful for open reduction and fxation of arch fractures. After the routine skin incision, adopting the deep subfascial approach provides better protection to the facial nerve as compared to the other commonly used approaches, namely, the subfascial and suprafascial procedures [87]. Figure 56.51 demonstrates the use of preauricular incision with deep subfascial dissection to expose a malunited zygomatic arch fracture.

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**Fig. 56.51** Preauricular approach demonstrating exposure of malunited zygomatic arch fracture

#### **56.9.3.10 Coronal Incision** [88] (Figs. 56.38, 56.52a, b and 85.1)

Tessier introduced the use of coronal incision to access the superior and lateral orbits bilaterally along with naso-orbitoethmoid complex in congenital facial reconstruction. The approach can be extended with a preauricular incision to include the exposure of the zygomatic body and the arches bilaterally. This incision also facilitates the temporal approach to the SZ suture [82]. Disadvantages of the approach include the extensive length of incision, dissection, temporal hollowing, scar alopecia, risk of injury to the supraorbital nerve, and temporal branch of the facial nerve.

#### **56.9.4 Fixation Methods**

Fixation methods for ZMC fractures have evolved through the ages.

Three basic fxation methods are available for ZMC fractures [1] (Table 56.1):,


The trend has gradually shifted from nonrigid fxation methods such as trans-osseous wiring, external pin fxation, and K wires to functionally rigid fxation methods including

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**Fig. 56.52** Coronal approach, intra-operative. (**a**) Exposure of arch demonstrating fractured zygomatic arch and FZ region (yellow arrows). (**b**) Arch after reduction and fxation at ZT and FZ region


miniplates and compressive screws. However, some of the nonrigid fxation modalities are still applicable in certain clinical situations. A brief description of all fxation methods is provided below along with their indications and limitations.


minuted. But it is an inaccurate technique with high relapse potential and increased possibility of infection.

Antral packing may be done either with a roller gauze pack or balloon. The technique followed for both is similar. The anterolateral wall of the maxilla is exposed by a Caldwell-Luc incision in the vestibule through which the fracture is inspected and manipulated to achieve reduction of the fragments. A trans-nasal antrostomy port is created in the inferior meatus. (refer Sect. 24.10, Fig. 24.24)


• K wires and Steinmann pins constitute an indirect method of fxation whereby the fractured zygomatic bone is fxed in a secure fashion to another stable point in the craniofacial skeleton. Such indirect anchorage may be obtained by using pins (1) to secure the fractured fragment to other stable bones or (2) to provide anchorage for connectors of an external fxator. The different techniques of indirect fxation that have been advocated for management of ZMC fractures include (Fig. 56.54):

(A) *Trans-zygomatic*—by this technique, the zygoma is frst reduced through an intraoral approach to

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enable adequate visualization of the entry of K wire/pin thorough the vestibular incision. The reduced ZMC is then stabilized by transfxing it to the contralateral zygoma using a K wire. The K wire is passed from the body of the reduced zygoma in a trans-facial fashion to engage the stable cortex of the contralateral zygoma by the use of a K-wire driver.


Indirect fxation may also be performed by the use of external fxators or a halo frame that can be attached to pins for anchorage. This may include the techniques described below.


**Fig. 56.54** Techniques for indirect fxation

rigidity requirements, anatomical site involved, presence of bone defcits, and biological considerations pertaining to protection of adjacent vital structures.

*Shape of plates:* The plates are chosen according to the contour of the bone that needs to be fxed; L plate for the ZM suture and a curved plate for the IOR.

*Presence of bone loss:* Comminuted fractures or bone loss may result in sagging of overlying soft tissues, especially in the ZM buttress region. This may be negated by using a broad mesh that bridges defects.

*Biological considerations:* Care must be taken to protect the roots, infra-orbital nerve and eye during fxation. In regions where the skin is thin, low-profle plates are preferred, 2 mm system for the ZM buttresses and 1.5 mm at the FZ, IOR, arch, and SZ suture [72].

*Stability requirements:* For ideal stability, screws of 6 mm length with a minimum of two screws on either side of fracture are essential. The only exception being the SZ suture where one screw on either side of the fracture line is adequate.

	- One-point fxation [92] refers to fxation at either the FZ or ZM suture. This has been found to be adequate in resisting post-reduction in-stability in simple tripod fractures while reducing hardware and surgical exposure.

Comparative studies have shown that one-point fxation at the ZM buttress has been found to more advantageous due to many reasons: (1) absence of external scarring; (2) ease of surgical access; (3) unlike the FZ region, adequate soft tissue cover is present; and there are no issues of plate palpability; (4) easier to remove the plate, when needed; and most importantly (5) ZM buttress is a better indicator of zygoma alignment than the FZ region due to the wider area of articulation. However, FZ may be used in fractures with comminuted ZM buttress.


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**Fig. 56.55** Fixation of zygomatic arch fracture with microcompressive screws a, b, and c. (**a**) Preoperative CT showing diastasis at the zygomatic root. (**b**) Intra-operative picture showing arch fxation with screw. (**c**) Postoperative CT showing adequate fracture reduction and screw fxation

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**Fig. 56.56** Types of fxation using miniplates. (**a**) One-point fxation at FZ suture; (**b**) one-point fxation at ZM buttress; (**c**) two-point fxation; (**d**) three-point fxation; (**e**) four-point fxation; and (**f**) fve-point fxation (the 5th articulation (SPZ) of the right is unseen and hence is depicted on the contralateral side for better understanding)


Though titanium miniplates are more commonly used to fx ZMC fractures, substantial clinical success has been obtained with use of bio-resorbable plates. They offer comparable post-reduction stability along with the added advantages of preventing thermal sensitivity and avoiding the need for second surgery to remove plates. Limitations associated with bio-resorbable plates are its technique sensitivity and increased operating time.

#### **56.9.5 Fixation of Zygomatic Arch**

The ORIF of arch fracture is indicated when the fragments are unstable after closed reduction and in cases where reestablishment of sagittal projection of face is needed. Fixation may be performed by one of the three methods, based on the fracture pattern (Fig. 56.57a, b, c): (1) a miniplate for an arch demonstrating a single fracture line (Fig. 56.52b), (2) a spanning adaptation plate (Fig. 56.62b) when the arch is multi-fragmented [98], and (3) a micro screw for an outfractured root or sagittal fracture of the arch [99] (Fig. 56.55). Kim et al. proposed plating on the superior surface of the upper border as an alternate line of arch fxation which negated the drawbacks associated with the conventional fxation [100] (Fig. 56.57).

#### **56.10 Soft Tissue Resuspension** [101, 102]

Accurate reduction and fxation of ZMC fractures frequently necessitates the use of multiple incisions on the midface which deglove the entire periosteum-muscle-fat complex of the midface and zygoma. Failure to re-approximate the dissected tissues may lead to undesirable changes in the soft tissue projection and form.

The various changes that may be a sequel to wide subperiosteal dissection of the midface include (1) cheek ptosis, (2) descent of the lower eyelid skin and infraorbital hollowness, (3) loss of malar prominence due to inferior displacement of the malar fat pad, and (4) exaggeration of the nasolabial fold [101].

Over the years many authors have documented these undesirable changes and proposed soft tissue resuspension methods to minimize them. This can be achieved by various methods (Fig. 56.58a): (1) re-approximating the incised periosteum using absorbable sutures, (2) by suspending the periosteum using heavy absorbable or nonabsorbable sutures to a drill hole placed in a superiorly positioned bony landmark

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**Fig. 56.57** Different fxation options for zygomatic arch fractures. (**a**) Adaptation plate. (**b**) Miniplate. (**c**) Compressive screw

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**Fig. 56.58** Soft tissue resuspension. (**a**) Graphical representation. (**b**) Resuspension of temporal soft tissues to deep temporal fascia (blue arrow)

such as the orbital rim [103], (3) resuspension of lateral facial and temporal soft tissues to the deep temporal fascia in the temporal region [104] (Fig. 56.58b), and (4) prophylactic endoscopic midface lift [101].

#### **56.11 Postoperative Care**

Following reduction of ZMC fractures, with or without fxation, the following measures are taken to maintain postsurgical stability and prevent soft tissue complications (Box 56.12):

#### **Box 56.12: Postsurgical Care**


#### **56.12 Pediatric Considerations**

#### **56.12.1 Nonsurgical vs. Surgical Intervention** [109]

The incidence of ZMC fractures is high in pediatric population due to its prominence [109]. In children, most authors favor a "nonsurgical" management or "reduction without fxation" of ZMC fractures due to concerns regarding "surgery/implant-induced" growth disturbances of facial skeleton and injury to teeth. However, literature supports ORIF of zygoma fractures which are grossly displaced or unstable after reduction. This is very important in pediatric population to (1) correct the facial asymmetry which may cause psychological impact, (2) restitute normal mouth opening to permit mastication, and (3) restitute globe position and function to enable normal vision and prevent development of phthisical eye or hypoplasia of zygoma, in the future.

#### **56.12.2 Approaches and Fixation Principles**

The preferred approaches include vestibular and lateral brow with minimal soft tissue dissection. Literature suggests onepoint fxation at FZ region as adequate for pediatric ZMC fractures because of the short lever arm forces between the FZ and IOR [110]. But current studies have demonstrated that two-point fxations provide adequate stability and are associated with the least complication rates when compared with one and three-point fxations. Similarly, fxation at the zygomaticomaxillary buttress had the least complications when compared against the fronto-zygomatic and infraorbital fxations [111]. In contrast, Defazio et al. proposed that plating at the FZ and IOR may be done conveniently in children below 6 years without any risk of damage to tooth buds [112].

#### **56.12.3 Osteosynthesis Methods**

Fixation techniques prior to year 2000 advocated titanium miniplates for pediatric midface. However they must be removed after 2 months to prevent any growth disturbances, plate migration, or burying of plate due to bone apposition. Microplates and self-drilling screws are also reported to give adequate stability and fxation in this age group without compromising vital structures [110]. Alternatively, bioresorbable plates may be used which became popular after year 2004 to negate the need for re-surgery for plate removal [113]. Figure 56.59a−f shows a case of displaced zygoma fracture in a 5-year-old boy managed by ORIF. The plates were removed after 2 months.

#### **56.13 Malunited ZMC Fractures** [114]

Malunion of the zygoma may be a sequel to two clinical scenarios, (1) a neglected ZMC fracture which was never treated and (2) an improperly treated fracture. The protocol for the management of the malunited zygoma is based on the type of deformity which may be either cosmetic or functional. The protocol followed by the author is demonstrated in Fig. 56.60.

*Deformities producing aesthetic concerns* may again be subdivided into those demonstrating facial asymmetry or those showing altered globe positions.

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**Fig. 56.59** ZMC fracture management in a pediatric patient. (**a**) Frontal view of patient with left-sided ZMC fracture. (**b**) Basal view demonstrating loss of facial projection and enophthalmos of left side. (**c**) Preoperative 3D CT image demonstrating en bloc displacement of ZMC. (**d**) Preoperative coronal section demonstrating separation at FZ

suture and lateral displacement of the body of zygoma. (**e**) Postoperative frontal view. (**f**) Postoperative basal view demonstrating restoration of facial projection and enophthalmos correction. (**g**) Postoperative 3D CT. (**h**) Post-operative coronal section

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*Functional defcits* secondary to malunited ZMC fractures essentially fall into three categories; Restricted mouth opening, parasthesia and diplopia.


infra-orbital foramen is not an uncommon fnding. The frst line of management in these patients is to perform a nerve release by an ostectomy around the infra-orbital foramen or by repositioning of the ZMC when it is compressing the nerve.

• Diplopia: The major cause for diplopia in ZMC fractures may either be gross displacement of the ZMC or mechanical restriction due to entrapment of orbital soft tissues (muscle, orbital septum, or fat) with resultant fbrosis or adhesions. Correction in these instances is achieved only by an osteotomy along with release of the entrapped tissues. These patients may also require orbital foor reconstructions if they present with foor defects that are large (>2 cm2 in area). Non-resolving diplopia may be subjected to management with prism glasses and/or strabismus surgery.

#### **56.14 Bilateral ZMC Fractures**

Bilateral fractures of the ZMC are a rare occurrence and present more diffculty in achieving adequate reduction. In contrast to unilateral fractures where the normal side is used as a guide to achieve symmetry on the fractured side, bilateral ZMC fractures are complex in management. Two options exist: (1) reducing the less displaced or comminuted side frst and using it as a reference for the more displaced side [116]. This may however result in compromised results, if three- or four-point fxation is not achieved, and (2) meticulous preoperative planning [43] by virtual surgical procedure to achieve the ideal facial width and projection. This involves a sequence of segmenting and virtually repositioning the fracture fragments to the "best possible ft" position. Once this is completed, the stents for intra-operative guidance can be generated.

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**Fig. 56.61** Use of Medpore onlay for malunited fracture

#### **56.15 Complications of ZMC Fractures** [3–5]

The incidence of postoperative complications increases with certain risk factors such as severe displacement, presence of sinus infection, and compound/comminuted ZMC fractures [37].

The various complications specifc to surgeries of the ZMC may be categorized as intra-operative, immediate postoperative, and delayed postoperative complications.

• *Intra-operative complications*: Commonly encountered intra-operative complications are bradycardia and bleeding. *Bradycardia due to oculocardiac/trigemino-cardiac* refex occurs typically during elevation of the ZMC [117]. Manipulation of zygoma stimulates the trigeminal nerve which subsequently stimulates the vagus nerve, due to the neuronal interconnections between them. Vagal stimulation is cardioinhibitory and hence results in bradycardia of varying degrees. This complication can be prevented by identifying risk factors and administering prophylactic vagolytic agents or minimizing nerve stimulation by administering regional blocks. However, management of bradycardia after its onset involves temporary cessation of manipulation and or medical management with atropine or epinephrine [64].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 56.62** Coronoidectomy for malunited ZMC fracture. (**a**) Pre-operative scan showing malunion of the right ZMC with fusion of the body of zygoma and coronoid process, and (**b**) post-operative scan demonstrating reduction and fxation of the right zmc with ipsilateral coronoidectomy.

*Brisk intra-op bleeding* can occur due to the sudden rupture of vessels (mainly infra-orbital artery) during reduction.


#### **56.16 Recent Trends**

Fractures of the ZMC are notorious for their sub-optimal outcomes due to over or under reductions. This may be attributed to diffculty in simultaneous visualization of its multiple articulations without increasing surgical morbidity due to additional exposures.

Technological advancements in the recent years have added ease as well as predictability to the reduction and fxation of these fractures while minimizing surgical morbidity. The most popular methods in contemporary surgical management are discussed below.


lofacial surgery" for additional information. The margin of error with use of intra-operative navigation is less than 1.2 mm with accurate restoration of facial symmetry. A case of deformity secondary to ZMC fracture treated using intra-operative navigation is illustrated in Fig. 56.63.


#### **56.17 Conclusion**

The ZMC fracture is one of the most complex fractures to reduce and fx, because of its propensity to undergo displacements in all three planes of orientation, along its fve articulations. Accurate reduction is challenging due to the diffculty in intra-operative assessment of reduction, inability to predict the rotation of the zygoma during reduction, and complexity involved in concomitant orbital fractures.

The surgical objectives must include (1) choice of incisions which provide maximal exposure with minimal morbidity, (2) increase in number of fxation points with increase in severity of fracture displacement, (3) achieving three-dimensional stability of ZMC complex and minimizing post-reduction complications, and (4) resuspension of overlying soft tissues to prevent sagging.

Preoperative planning and intra-operative imaging play a great role in improving accuracy of fracture reduction while minimizing surgical exposure and post-reduction complications.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 56.63** Intra-operative navigation for ZMC fracture. Multiplanar sections demonstrating superimposition of patient CT (white) and surgical. Plan (pink) with use of intra-operative navigation to verify position during surgery (blue pointer)

**Acknowledgment** The authors would like to acknowledge the efforts of the postgraduate trainees Dr. Vijitha and Dr. Logitha Sri towards the illustrations.

### **56.18 Case Scenarios**

**Case Scenario 1: Fracture of right ZMC** (Fig. 56.64)

#### **Patient: 21-Year-Old Male, with History of RTA**

*Preoperative CT* (Fig. 56.64a, c) showing right-sided fracture of the ZMC and arch with undisplaced frontal bone.

The sections demonstrate:


*Surgical plan:* Reduction of ZMC fracture with fourpoint fxation

#### *Surgical procedure*:

	- 1. Trans-conjunctival incision with extended lateral approach
	- 2. Intraoral buccal sulcus approach

#### *Postoperative CT* (Fig. 56.64b, d, e):

CT demonstrating optimal reduction of fractured ZMC and arch. The successful surgical outcome may be appreciated by the approximation and fxation at the SZ suture, which is the most reliable indicator of accurate ZMC reduction.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 56.64** Case scenario 1. (**a**) Preoperative 3D CT-frontal view demonstrating fractures. (**b**) Postoperative 3D CT-frontal view demonstrating fxation. (**c**) Preoperative 3D CT-basal view demonstrating arch

#### **Case Scenario 2: Fracture of left ZMC and orbital foor** (Fig. 56.65 a–h)

#### **Patient: 27-Year-Old Male with History of RTA and delayed presentation after 2 months** *Preoperative CT fndings* (Fig. 56.65a, b):

• En bloc fracture of the left ZMC with diastasis at the left infra-orbital rim, zygomatic arch, and FZ and SZ


*Surgical plan*: ZMC osteotomy, repositioning, and internal fxation

fracture. (**d**) Postoperative 3D CT-basal view demonstrating arch reduction. (**e**) Postoperative 3D CT demonstrating fxation at SZ suture. (**f**) Intra-operative fxation at SZ suture

#### *Surgical procedure:*


#### *Postoperative features* (Fig. 56.65e, f and h):

The postoperative CT demonstrates optimal reduction and fxation of the left ZMC with reconstruction of the left orbital foor defect with titanium implant.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 56.65** Case scenario 2. (**a**) Preoperative 3D CT-frontal view demonstrating fractures. (**b**) Preoperative 3D CT-basal view. (**c**) STL model surgery with pre-contoured plate. (**d**) STL model demonstrating mirroring of normal side and plate adaptation. (**e**) Postoperative 3D CT-frontal view demonstrating fxation. (**f**) Postoperative 3D CT-basal view demonstrating fxation. (**g**) Preoperative CT-sagittal view demonstrating foor fracture. (**h**) Postoperative CT-sagittal view demonstrating reconstruction of foor with orbital mesh

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Orbital Fractures**

**57**

Ananthanarayanan Parameswaran, Madhulaxmi Marimuthu, Shreya Panwar, and Beat Hammer

#### **57.1 Introduction**

Orbital fractures are unique among cranio-maxillofacial (CMF) fractures. They have functional, cosmetic, and psychological implications. Most importantly they are among the few true emergencies in the realm of CMF trauma. Management of orbital fractures poses a challenge to every surgeon because of its complex anatomy, relationship to vital structures such as the globe and the brain, and its direct infuence on the most precious of senses, *Vision.*

The orbit is a small bony cone flled with numerous vital and delicate structures, which require absolute precaution while handling and immense precision in its reconstruction. The principles of managing orbital trauma differ signifcantly from rest of the CMF fractures, which mandate a thorough understanding of its morphology and biodynamics. Choosing the appropriate indication for intervention and management protocol is critical in achieving the desired sur-

Department of Orbit and Oculoplasty, Aravind Eye Hospitals, Chennai, India

M. Marimuthu

Department of Oral and Maxillofacial Surgery, Saveetha Dental College and Hospital, Chennai, India

S. Panwar

Department of Oral and Maxillofacial Surgery, Meenakshiammal Dental College and Hospital, Chennai, India

B. Hammer

CFC Hirslanden Kopf Zentrum, Aarau, Switzerland e-mail: Beat.Hammer@hirslanden.ch

gical outcome. This chapter aims to answer the questions of the *When*, *Why*, and *How* of managing orbital trauma.

#### **57.2 Surgical Anatomy of the Orbit**

The orbits are bilateral bony cavities which house the globes. Each orbit is made up of seven bones: the maxilla, frontal bone, zygomatic, sphenoid, ethmoid, lacrimal, and the palatine bones (Fig. 57.1). The orbital cavity is a pyramidal structure with a quadrilateral base anteriorly, forming the orbital aperture, and the apex posteriorly which ends at the optic foramen. The apex is superomedially placed, while the base is directed anterior and lateral. The orbit encases two fssures: (1) the inferior orbital fssure also called the sphenozygomatic fssure and (2) the superior orbital fssure otherwise called as the inter-sphenoidal fssure (Fig. 57.2). The major structures within the orbit are provided in Box 57.1.

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_57) contains supplementary material, which is available to authorized users.

A. Parameswaran (\*)

Department of Oral and Maxillofacial Surgery, Meenakshiammal Dental College and Hospital, Chennai, India

Department of Orbit, Oculoplasty, Reconstructive and Aesthetic Surgery, Shankara Nethralaya, Chennai, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1201

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_57

#### **Fig. 57.1** Bones forming the orbit

**Fig. 57.2** Structures passing through the superior and inferior orbital fssures

©Association of Oral and Maxillofacial Surgeons of India

```
©Association of Oral and Maxillofacial Surgeons of India
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#### **Box 57.1 The Major Structures that Occupy the Orbit**


The orbits have an average height of 35 mm and a mediolateral width of 40 mm [1–3]. The intra-orbital volume of an adult is approximately 30 cc, while the volume of the globe is 7 cc [4]. Generally, the orbital and globe volumes are bilaterally symmetrical at any stage of growth. The medial walls are parallel to each other and around 45–50 mm in length, while the lateral walls are around 90° to each other and 40–45 mm long (Fig. 57.3).

The orbital skeleton may essentially be divided into walls and rims. These include the orbital roof, foor, and medial and lateral walls. The rims include the inferior, superior, medial, and lateral orbital rims. A brief description of the structure of the orbital cavity is provided below.

#### **57.2.1 Orbital Walls**

*The roof* (Fig. 57.4a) is formed by a concave broad plate of the frontal bone which delineates the orbital contents from the cranial cavity. The posterior portion of the roof has a small contribution from the lesser wing of the sphenoid. The anterolateral portion has a shallow depression called the lacrimal fossa, while 5 mm behind the medial aspect of the supraorbital rim is the trochlear fossa which has the cartilaginous pulley of the superior oblique muscle. The roof is triangular in shape and ends in optic foramen, which is the entry of the optic nerve into the orbit.

In older patients there may be spots of resorption in the orbital roof which may cause the dura to adhere to the periorbita of the roof. The junction of the medial wall and the roof has a suture line which lies in close proximity to the cribriform of the ethmoid and is prone for fragmentation. This may be a major concern for CSF leak into the orbits or the nose or at times both.

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**Fig. 57.3** Diagrammatic representation of the various measurements of the orbit and the globe

The roof is separated from the lateral orbital wall by the superior orbital fssure which serves as a passage of entry for the cranial nerves III, IV, V1, and VI into the orbit. The other structure coursing through the fssure is the ophthalmic vein. On the anterior aspect of the roof, at the junction between the medial 1/3rd and the lateral 2/3rd of the supraorbital rim is the supraorbital foramen which transmits the supraorbital neurovascular bundle [1–3, 5].

*The medial wall* (Fig. 57.4c) is quadrangular in shape and is constituted by the ethmoid bone in the center. The anterosuperior aspect is formed by the frontal bone, while the anteroinferior part is formed by the lacrimal bone. The sphenoid bone forms the posterior part of the medial wall. The infraorbital rim continues along the anterior aspect of the medial wall forming the anterior lacrimal crest which is a part of the frontal process of the maxilla, while the superomedial aspect of the supraorbital rim continues inferiorly as the posterior lacrimal crest which is formed by the lacrimal bone. Between these crests lie the fossa which houses the lacrimal sac. This is of importance during access planning for surgery of the medial wall and the anteromedial aspect of the infra-orbital rim.

The anterior and posterior ethmoidal foramen are located along the fronto-ethmoidal suture which signifes the height of the cribriform plate. The anterior ethmoidal foramen which transmits the anterior ethmoidal artery and nerve lies approximately 22–25 mm behind the medial orbital rim while the posterior ethmoidal foramen which transmits the posterior ethmoidal artery and the spheno-ethmoidal nerve is present about 12 mm posterior [6]. The optic foramen is in continuation of the medial wall and is approximately placed 45–50 mm behind the medial rim. The safe distances the sur-

**Fig. 57.4** (**a**) Roof, (**b**) lateral wall, and (**c**) medial wall of the orbit

geon needs to remember are 24 mm for the anterior ethmoidal artery, with an additional 12 mm for the posterior ethmoidal vessel and a further 6 mm as the limit to stay away from the optic foramen making it *24-12-6*, an easy formula to remember. One important structure which may be involved in medial wall trauma is the medial rectus muscle which can get entrapped causing ocular motility disturbances.

*The lateral wall* (Fig. 57.4b) is the thickest wall and is made primarily by the orbital surface of the zygomatic bone and the greater wing of the sphenoid. A small bony projection seen on the lateral wall is the Whitnall's tubercle which lies 11 mm below the fronto-zygomatic suture and 4 mm behind the rim (Fig. 57.7).

This tubercle forms the attachment of the 4L's:


A small groove may be seen at the anterior end of the inferior orbital fssure which transmits the zygomatico-facial and zygomatico-temporal vessels. These course through the zygoma and exit through independent foramina to supply the face and the temporal regions.

*The foor* (Fig. 57.5a, b) follows a gentle slope from its medial to lateral side. The highest point lies in the posteromedial aspect of the foor forming a bulge called the "Hammer's key area" [7] (Fig. 57.5a), which infuences the position of the globe in the anteroposterior axis. In the sagittal view, the foor follows a "lazy S" shape with the anterior part concave and the posterior convex. The reconstruction of this convexity is important to maintain the anterior position of the globe (Fig. 57.5b). The foor is separated from the lateral wall by the inferior orbital fssure. The fssure communicates with the pterygopalatine fossa extra-orbitally. The maxillary division of the V nerve and its branches, the infraorbital artery, and branches of the sphenopalatine ganglion are transmitted through the posteromedial aspect of the fssure, while the inferior ophthalmic veins pass through the lateral aspect to communicate with the pterygoid plexus. The foor is formed by the zygomatic bone and the maxilla with a small contribution from the orbital process of the palatine bone in the posteromedial aspect. A rough area at the anteromedial angle of the foor behind the infra orbital rim forms the attachment of the inferior oblique muscle. The infraorbital groove originates from the inferior orbital fssure and transmits the infra-orbital neurovascular bundle.

#### **Orbital Rims:**

The rims are superior, inferior, medial, and lateral. Three major bones—the maxilla, zygomatic bone, and frontal bone—make up the rims of the orbit. The width of the rims is greater than its height making it into a rectangular form. The presence of the maxillary sinus and the insertion of the inferior oblique muscle make the infra-orbital rim more prone for fracture and comminution.

#### **57.2.2 Muscles of the Orbit** (Fig. 57.6a)

Muscles in relation to the orbit can be divided into


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**Fig. 57.5** The orbital foor in (**a**) frontal view demonstrating the (A) orbital process of palatine bone and (B) "Hammer's key area." (**b**) Sagittal view of the foor with the "lazy S" form

The muscles of the lid are:


The levator palpebrae superioris along with the four recti, and the two obliques form the seven extraocular muscles of the human eye.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 57.6** Diagram of right eye demonstrating (**a**) the extraocular muscles and (**b**) the movements they cause. (**c**) The fascial sheath. (*SR* - Superior Rectus, *IR* - Inferior Rectus, *MR* - Medial Rectus, *LR* - Lateral

The origin of the superior rectus is from the common tendinous ring superolateral to the optic canal, and its insertion is into the upper part of the sclera. Its function is to produce elevation of the eye and to move the cornea upward and medially helping in adduction and medial rotation.

The origin of the medial rectus is from the medial aspect of the tendinous ring and inserts into the medial surface of the sclera. The medial rectus helps in moving the eye medially (adduction), and bilateral action of the medial rectus helps in medial convergence of both the corneas. A suspensory attachment to the lacrimal crest is also seen on the medial orbital wall where it blends with the medial canthus and the check ligament (Fig. 57.6c) [2, 3, 6, 8]. The origin of the lateral rectus is from the lateral part of the common tendinous ring, and it inserts into the lateral surface of the sclera. Its primary function is to move the eye laterally (abduction).The inferior rectus arises from the common tendinous ring, below the optic canal, and inserts into sclera below the cornea. It is responsible for depression and lateral rotation of the eye.

The inferior rectus followed by the medial rectus are the most common muscles to be entrapped secondary to orbital trauma and may need to be explored and released surgically as indicated. Delayed release of the recti may cause signifcant necrosis and fbrosis of the muscles hampering return to normal function.

The superior oblique arises superomedial to the optic canal. It has a pulley action at the trochlea on the anteromedial aspect of the orbital roof and inserts into the sclera behind the equator of the globe. The contraction of the muscle produces depression of the cornea and movement of the eye laterally with medial rotation (intorsion).

The inferior oblique muscle arises from the orbital surface of the maxilla lateral to the nasolacrimal groove and inserts into the lateral part of the sclera behind the equator between the inferior and lateral recti muscle. It produces Rectus, *SO* - Superior Oblique, *IO* - Inferior Oblique, *CL(MR)* - Check Ligament of Medial Rectus, *CL(LR)* - Check Ligament of Lateral Rectus, *SL* - Suspensory Ligament

elevation of the cornea and helps in moving the eye laterally with lateral rotation (extorsion).

#### **57.2.3 Movements of the Eye and Their Innervation**

#### **Box 57.2 The Movements of the Eye**


The different movements of the eye are enumerated in Box 57.2. These are facilitated by the extraocular muscles described above and are contained by the check ligaments. The inferior oblique and inferior rectus muscles which course the foor of the orbit serve as the inferior check ligaments. The fascia of the levator palpebrae superioris, which is anchored to the Whitnall's tubercle laterally and the trochlea medially, acts as the superior check ligament [8].

The contraction of the orbicularis oculi innervated by the facial nerve dictates the closure of the upper eyelid. The movements of the globe within the orbit are however dictated by the synchronous movements of the extraocular muscles of the orbit. The oculomotor nerve innervates all the extraocular muscles other than the lateral rectus which is supplied by the abducent nerve and the superior oblique supplied by the trochlear nerve. Refex closure of the eyelids occurs via the sympathetic pathways traveling to the smooth muscles of the upper and lower eyelids.

**Fig. 57.7** The tarsal apparatus and the orbital septum

#### **57.2.4 Orbital Septum and Tarsal Plates**  (Fig. 57.7)

The supporting framework for the eyelid is formed by a dense fbrous tissue called the orbital septum which condenses at the lids as the tarsal plates. The orbital septum which separates the orbital and lid contents attaches to the bone and becomes the periorbita inside the orbit and periosteum outside the orbit. The septum of the lower eyelid attaches to the orbital rims, while the septum of the upper eyelid is attached intra-orbitally behind the equator of the globe. The tarsal plates add rigidity to the lids and also serve attachments of multiple muscles and membranes [1, 3].

#### **57.2.5 Conjunctiva**

The conjunctiva is the transparent mucous membrane that covers the front surface of the globe and the inner surface of the eyelids.

This has two segments:

1. The bulbar conjunctiva that covers the anterior part of the sclera (the "white" of the eye)

2. The palpebral conjunctiva otherwise known as tarsal conjunctiva which covers the inner aspect of the eyelids

#### **57.2.6 Fascial Sheath of the Eyeball** (Fig. 57.6c)

The fascial sheath of the eyeball is called the Tenon's capsule [8]. It extends from the optic foramen to the sclerocorneal junction enveloping the eyeball on the inferior aspect. It attaches to the sclera on the anterior and posterior surfaces of the eyeball and becomes continuous with the fascia of the muscles posteriorly and around the inferior oblique muscle. The fascial sheath of all muscles blend together and form a continuous fascial band called the suspensory ligament of the eye that provides support for the eyeball [8, 9].

#### **57.2.7 Orbital Fat**

The orbital fat is present both intra- and extra-conally. They cushion the globe and muscles of the orbit. The extra-conal fat determines and infuences the position of the globe. This may be altered either due to herniation or atrophy secondary to fractures of the orbit resulting in enophthalmos.

#### **57.3 Classifcation System**

Manson [10] and colleagues classifed the fractures based on the energy of impact, the degree, and extent of comminution and displacement observed on CT:


Converse and Smith [11] termed them "pure" or "impure" based on the involvement of orbital rims (Fig. 57.8):


Hammer [7] described four classes of orbital fractures based on their occurrence with other fractures of the face (Fig. 57.9):


#### **57.4 Blowout and Blow-In Fractures**

Smith and Converse in 1960 recognized the phenomenon of blowout fractures (Fig. 57.10a). These fractures may involve entrapment or herniation of periorbital tissues resulting in restricted eye movements and/or enophthalmos due to reduction in the volume of intra-orbital contents [3, 11].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 57.8** CT scans showing Pure (**a** and **c**) and impure (**b** and **d**) blowout fractures of the orbit

"Blow-in" type of orbital fractures was described by Dingman and Natvig [3, 12] in 1964 wherein the intra-orbital space is reduced by an internally displaced bony fragment (Fig. 57.10b). Such types of fractures are usually accompanied with proptosis on the affected side [13].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 57.9** CT scan images showing types of orbital fractures: (**a**) orbito-zygomatic, (**b**) internal orbital, (**c**) naso-orbito-ethmoid type, and (**d**) orbit with complex facial fractures

**Fig. 57.10** CT scans demonstrating a blowout of the medial orbital wall and foor (**a**) and a blow-in fracture of the orbital roof (**b**)

©Association of Oral and Maxillofacial Surgeons of India

#### **57.5 Biomechanics of Injury**

One of the frst mechanisms of orbital wall fractures was suggested by Pfeiffer [14] in 1943, called *globe-to-wall theory or hydraulic theory* (Fig. 57.11a), wherein posterior displacement of the globe after sustaining a direct hit was propounded to transmit force along the walls resulting in fracture of the thinner walls. There are two more widely accepted mechanisms of orbital wall fractures, namely, the:


First proposed by King [16] in 1944, retropulsion theory suggests that sudden increase in intra-orbital pressure caused by direct hit from a large object creates stresses along the orbital walls resulting in fractures at the areas of least thickness. The buckling theory or transmission theory explains the injury through a ripple effect created in the foor. The ripple thus created causes compression in an anteroposterior direction and resultant fracture at the posteromedial part of the orbital foor commonly [17, 18].

#### **57.6 Initial Assessment**

After initial stabilization of the patient, a thorough facial examination is performed in a way similar to any facial fracture. Special consideration is given to a detailed ophthalmic evaluation followed by eliciting signs and symptoms signifcant for periorbital trauma which are discussed below. The frontal area and supraorbital rim are examined frst, with a logical progression downward, including the lateral and infra-orbital rims, although extensive edema in this area may obscure any steps making the palpatory examination diffcult [3, 7, 19–22].

#### **57.6.1 Ophthalmologic Examination**

The American Association of Ophthalmology [23] advocates an 8-point ophthalmological examination which includes the following (Box 57.3):

1. *Visual acuity*: Visual acuity test for each eye is recorded using a Snellen chart (Fig. 57.12a) and includes ability to read letters, count fngers, perceive hand movements, and light perception. If visual acuity is extremely poor and recording of a chart test fails, the patient is subjected to a fnger counting test or at times even assessed for primary light perception alone.

	- (a) size,
	- (b) shape,
	- (c) symmetry,
	- (d) and direct/indirect refex to light.

*Glaucoma*, previous history of surgery, and/or injury to ocular system may also account for anisocoria or irregular pupils. Peaked or irregular pupils may also be indicative of perforation of the globe. The swinging fashlight test is performed for relative afferent pupillary defect (RAPD) (Fig. 57.12b).


©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 57.13** Demonstration of the method of performing intraoperative forced duction test (**a**) by grasping the limbus (sclero-corneal junction) and (**b**) by grasping the inferior rectus muslce

is a range between 10 and 21 mmHg with the mean being around 15 mmHg. Low IOP may be suggestive of a ruptured globe or detached retina, while increased IOP may indicate hyphema, glaucoma, or an orbital compartment syndrome like "retrobulbar hemorrhage." A pressure of more than 30 mmHg is an ophthalmological emergency.

5. *Visual felds*: Visual felds for each eye are checked by asking the patient to determine movements at the periphery of the examiner's own visual feld, while at a distance of about 2 ft from each other. Loss of feld may be suggestive of compressive or ischemic injuries to the optic nerve with or without damage to the visual pathway. Goldmann visual feld test can also be employed to objectively chart binocular visual feld loss wherein patient is asked to look at a center of the chart and is required to track a point source of light.


#### **Box 57.3 "8-Point" Ophthalmic Examination Advocated by the American Association of Ophthalmology [23]**


#### **57.6.2 Clinical Features**

A good evaluation of the skeletal and soft tissue components of the orbit as well its associated adnexa (eyelids, lacrimal apparatus, etc.) is mandated. The common clinical features that are presented with in orbital trauma are provided in Box 57.4.

#### **Box 57.4 Common Clinical Features in Orbital Trauma Are Enumerated Below**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 57.14** Clinical pictures demonstrating (**a**) edema of the left periorbital region, (**b**) left-sided periorbital ecchymosis and subconjunctival hemorrhage, and (**c**) soft tissue injury of the left eyelid and supraorbital region

Clinical signs and symptoms that are more exclusive to orbital trauma are discussed further in more detail.

#### **57.6.2.1 Enophthalmos/Hypophthalmos**  (Fig. 57.15a, b)

Any change in the orbital volume directly impacts the position of the globe and its anteroposterior projection and supero-inferior position [24]. Clinically enophthalmos can be detected by an exaggerated suprapalpebral fold and reduced projection on viewing from an inferior view or worm's view. Hertel's or Naugle's exophthalmometer can also be used to quantify and measure the discrepancy. Other causes of enophthalmos implicated are traumatic atrophy of intra-orbital fat, infections causing cicatricial contraction of retrobulbar tissues, and dislocation of trochlear attachment of superior oblique muscle due to trauma [25, 26]. Hypophthalmos is noted as a change in the horizontal pupillary levels.

#### **57.6.2.2 Retrobulbar Hemorrhage** (Fig. 57.16)

Retrobulbar hemorrhage is a vision threatening emergency which occurs due to accumulation of blood in the retrobulbar space. This causes increased intra-orbital pressure resulting in compression or stretching of the optic nerve and reduced perfusion to the eye. Orbital trauma especially blunt injury may be associated with retrobulbar hemorrhage which warrants immediate attention. However this may also occur as a complication following surgery to the orbit or pathologies like an aneurysm. Acute post-septal hemorrhage limited anteriorly by the orbital septum and posteriorly by bone may cause permanent loss of vision by creating a compartment syndrome [27]. It presents as reduced ocular motility, elevated intraocular pressure, proptosis, and diminishing vision. In unconscious patients, pupillary assessment, increased pressure, and presence of relative afferent pupillary defect or RAPD are usually diagnostic.

#### **57.6.2.3 Lacrimal System Injuries**

Due to its close topographical location to the orbital complex, nasolacrimal system especially the duct may be involved in traumatic injuries to the orbit. Injury to the canaliculi or the nasolacrimal ducts in naso-orbito-ethmoidal injuries may present as epiphora [28]. Patency of

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**Fig. 57.15** Clinical photograph of a patient with both (**a**) hypophthalmos and (**b**) enophthalmos of the right globe

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**Fig. 57.16** (**a**) Axial, (**b**) coronal, and (**c**) sagittal section CT scan images demonstrating left-sided retrobulbar hemorrhage

the naso-lacrimal duct and sac can be verifed by the Jones tests 1 and 2 or by a simple lacrimal probing test with insertion of a Crawford silicone intubation tubes though the canaliculi and visualization of the same at the distal end of the disruption. ROPLAS test or regurgitation on pressure over lacrimal sac may be performed clinically to elicit posttraumatic blockage of the nasolacrimal duct (Fig. 57.17c). Confrmation however is obtained with a CT dacryocystogram or CT-DCG (Fig. 57.17a, b). Reconstruction of the lacrimal drainage system is achieved by simple intubations or a formal dacryocystorhinostomy as indicated by the clinical scenario.

#### **57.6.2.4 Oculocardiac Refex (Trigeminocardiac Refex)**

First described by Dagnini and Aschner in 1908, oculocardiac refex is bradycardia on manual compression of the eyes. The most common traumatic etiology is the incarceration of inferior rectus muscle in trap-door fractures of the orbital foor [29, 30]. Other causes that may present with oculocardiac refex are retrobulbar hemorrhage, white-eyed blowout fractures and orbital surgery.

#### **57.6.2.5 Superior Orbital Fissure Syndrome**  (Box 57.5)

Post-traumatic superior orbital fssure syndrome may be attributed to pressure exerted on the contents of the superior orbital fssure due to hemorrhage or impingement by fractured fragments.

Superior orbital fssure syndrome was frst described by Hirschfeld in 1858 [31, 32] and symptoms include:


**Fig. 57.17** (**a**) Sagittal section CT DCG demonstrating patent NLD with draining dye and (**b**) blocked NLD with no drainage of the dye. (**c**) Clinical photograph of patient with left-sided NOE fracture demonstrating regurgitation of contents due to blocked left naso-lacrimal duct ROPLAS positive

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**Fig. 57.18** Clinical pictures and CT scans of patient with orbital apex syndrome. (**a**) Clinical picture demonstrating left-sided orbito-zygomatic trauma with clinically evident ptosis, (**b**) 3D CT demonstrating comminuted zygomatico-orbital fracture with medial displacement of the greater wing of sphenoid, (**c**) clinical picture of patient 2 weeks post-surgery with resolution of ptosis, (**d**) post-operative 3D CT show-


ing ORIF, (**e**) pre-operative axial CT demonstrating total compression of the left optic canal (yellow arrow), (**f**) pre-operative coronal CT demonstrating compression of the left superior orbital fssure (yellow arrow), (**g**) post-operative CT showing decompressed left optic canal (yellow arrow) and (**h**) post-operative coronal CT showing decompresison of the left superior orbital fssure (yellow arrow)

Management may be conservative or exploratory surgery of the orbit including surgical decompression [33].

#### **57.6.2.6 Orbital Apex Syndrome** (Fig. 57.18) (Box 57.5)

In severe orbital trauma, optic nerve may also be implicated due its close proximity to the superior orbital fssure [31, 34]. The term orbital apex syndrome was frst coined by Kjaer in 1945 [35], and the symptoms include all features **Fig. 57.19** (**a**, **b)** Axial CT scan of patient with direct traumatic optic neuropathy demonstrating a skull base fracture and bony spicule at the entry of the optic nerve into the canal

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of superior orbital fssure syndrome along with partial or loss of vision.

#### **57.6.2.7 Traumatic Optic Neuropathy (TON)**  (Box 57.5)

TON may be defned as an acute injury to the optic nerve with impairment of visual function. It may occur as a result of:


Clinical features of TON include:


Management of TON is handled under the section of orbital emergencies.

#### **57.6.3 Investigations**

Conventional radiographs have a minimal role in the diagnosis and planning of orbital fractures. CT scans (Fig. 57.20a–c) have long been considered the "gold stan-

#### **Box 57.5 Comparison of Clinical Features of Traumatic Optic Neuropathy, Superior Orbital Fissure, and Orbital Apex Syndromes**


dard" in orbital trauma. The scans are usually ordered in fne cuts of 0.5 mm and taken in all the three planes. The coronal and the sagittal scans are important in the diagnosis

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**Fig. 57.20** CT scans showing (**a**) axial section with fracture of the medial wall of the right orbit, (**b**) coronal section showing fractures of the medial wall and foor, and (**c**) sagittal section showing fracture of the foor with fbrosis of the inferior rectus to the posterior ledge (yellow arrow)

**Fig. 57.21** MRI (**a**) coronal and (**b**) sagittal sections, demonstrating entrapment of the medial rectus (yellow arrows) and medial displacement of the optic nerve (left orbit)

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of fractures of the foor and the roof, while the axial scans provide better information regarding the fractures of the medial and lateral walls. Axial sections are also important to study the optic canal integrity.

Indications for an MRI (Fig. 57.21a, b) scan are limited to determining soft tissue injuries and entrapment of muscles and to assessing damage to the optic nerve. It is also used to identify intra-orbital herniation of brain in the case of blowin fractures.

#### **57.7 Approaches to the Orbit**

**Box 57.6 Surgical Approaches to the Orbit**


#### **57.7.1 Transcutaneous Approaches**

	- (a). Lateral transcutaneous approaches
		- (i) Lateral brow incision
		- (ii) The upper lid blepharoplasty and the sub brow approaches
	- (b). Lower eyelid approaches (Also refer Figs. 56.44, 56.45)
		- (i) Sub-ciliary
		- (ii) Sub-tarsal
		- (iii) Infra-orbital (Video 57.1)

#### **57.7.1.1 Lynch**

This incision described by Lynch [36] in 1921 is a semilunar-shaped incision (Fig. 57.22a) placed between the nasal dorsum and the medial canthal ligament that provides direct access to the canthal apparatus and the medial orbital rim and wall. The major drawbacks of this particular incision are chances of developing a web and hence an unsightly scar. There may also be risk of damage to the medial canthal tendon and the lacrimal apparatus that is present infero-laterally. Recent modifcations of the Lynch incision have accommodated options to reduce the scarring by the use of "Z" plasties (Fig. 57.22b, c) and other esthetic incision designs.

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**Fig. 57.22** Diagrammatic representation of the (**a**) classical Lynch incision and (**b, c**) modifcation with "Z" plasty

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**Fig. 57.23** Diagram and intraoperative picture showing extended glabellar approach to the medial orbit

## **57.7.1.2 Extended Glabellar Approach**

(Fig. 57.23) The extended glabellar incision or a horizontal "Y" approach involves a small Y-shaped incision with the fork extending over the upper and lower lid crease with the long arm across the nasal dorsum over the glabellar region. This approach provides excellent access to the medial canthal tendon apparatus and also provides enough room for medial orbital wall exploration cephalad to the tendon.

#### **57.7.2 Trans-caruncular Approach**

The trans-caruncular route provides excellent exposure to the medial orbit without causing any esthetic concern. The caruncle is a papular structure seen medial to the plica semilunaris which is a fold of conjunctiva in medial canthal region. An avascular plane is located deep to the caruncle between the medial orbital septum and the Horner's muscle which on dissection exposes the medial wall of the orbit (Fig. 57.24a) [37].

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**Fig. 57.24** (**a**) Diagram and (**b**) intraoperative pictures showing marking for trans-caruncular approach to the medial orbit and (**c**) exposure of the medial orbital wall. (Courtesy: Dept of Orbit & Oculoplasty, Shankara Nethralaya, Chennai)

After placing retraction sutures on upper and lower eyelids, gentle medial traction is applied over the skin of the nasal dorsum, and incision is placed lateral to the caruncle, while avoiding injury to the lacrimal puncta or canaliculi (Fig. 57.24b). The length of the incision is between 1.5 and 2.5 cm. Dissection through the fbers of the Muller's muscle exposes the medial wall just posterior to the posterior lacrimal crest (Fig. 57.24c). For additional exposure of associated orbital foor fractures, a C-shaped approach can be used including a transconjunctival incision with or without lateral canthotomy and inferior cantholysis in conjunction with the trans-caruncular approach.

As the lateral transcutaneous and lower lid approaches also fnd use in the management of fractures of the zygomatic complex fractures, they are discussed in detail in chapter on zygomatic complex fractures.

#### **57.7.3 Transconjunctival Approach** (Fig. 57.25)

The infra-orbital rim and orbital foor defects can be accessed through a transconjunctival incision (Video 57.2).

Its advantages include:


A historical perspective of the description of the transconjunctival approach and its evolution into the most favored approach for access to the foor and medial wall of the orbit along with the infra-orbital rim is provided in Box 57.7.

#### **Box 57.7 Evolution and Modifcations of the Transconjunctival Approach**


#### **Pre-septal Approach** (Fig. 57.26)

The incision is marked 2–3 mm posterior to the tarsal plate along the mediolateral length of the lower palpebral conjunctiva. Dissection is performed along the subconjunctival plane and is carried down toward the inferior orbital rim. This maintains the plane anterior to the orbital septum. Retraction sutures may be placed on the vestibular portion of the conjunctival fap with traction in superior direction, to provide additional protection to the globe. On reaching the facial surface of the infra-orbital rim, the periosteum is incised about

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**Fig. 57.25** (**a**) Diagram showing trans-conjunctival approach and its modifcations - A. Transconjunctival, B. Trans-caruncular & C. Lateral canthotomy. (**b**) Intra-operative picture of trans-conjunctival with the lateral canthotomy modifcation. The picture also shows an upper lid blepharoplasty incision used to access the fronto-zygomatic suture

2 mm inferior to the rim. This is followed by subperiosteal dissection and exploration of the orbital foor by retracting the globe and orbital contents superiorly. Approximately 2–3 mm distance must be maintained from the lower end of the tarsal plates while making the initial conjunctival incision failing which there is vertical shortening of the lower eyelid and entropion post-operatively.

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**Fig. 57.26** Diagrammatic representation of the pre-septal and retroseptal modifcations of the transconjunctival approach

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**Fig. 57.27** (**a**, **b**) Diagram of the trans-antral endoscopy assisted approach to the orbital foor

#### **Retroseptal Approach** (Fig. 57.26)

In the retroseptal type, the conjunctival incision is made near the fornix spanning mediolaterally just short of the caruncle. Dissection is posterior to the orbital septum providing a fast and direct access to the foor when compared to the preseptal type [38]. However, orbital fat is encountered before approaching the orbital foor, which may prove bothersome for dissection and manipulation. The periorbita is incised immediately posterior to the rim after superior retraction of the fat and globe with a malleable retractor. This is followed by subperiosteal dissection and exploration of the foor defect. Excessive manipulation of the orbital fat during orbital reconstruction increases the risk of enophthalmos due to fat disintegration [39, 40]. Placement of the incision too low into the fornix may damage the inferior oblique muscle and retractors of the lower eyelid, compromising esthetics post-operatively due to lower lid entropion.

#### **57.7.4 Trans-antral Endoscopic-Assisted Approach** (Fig. 57.27a, b)

The trans-antral approach was attempted by Converse and Smith [41] as early as the 1960s. Entry to the antrum is gained through a transoral Caldwell Luc procedure and a 0° or 30° endoscope may be used to visualize the orbital foor.

#### **57.7.5 Coronal Approach**

The coronal approach offers the most extensive exposure of the entire upper and middle third of the face including the orbit. A detailed description of the same is provided in Chap. 85 on access osteotomies.

#### **57.8 A Clinical Sequence for Treatment Planning and Management of Orbital Fractures**

A clear understanding of the various patterns of orbital fractures and their clinical implications is absolutely necessary to design and formulate a plan for their reconstruction. The basic management guidelines for the common variations in orbital fractures are detailed below (see Hammer [7] classifcation, Fig. 57.9).

### **57.8.1 Type I (Orbito-Zygomatic)**

Concomitant fractures of the zygomatic complex and the orbit mandate ORIF of the zygomatic complex frst, followed by internal orbital reconstruction. This sequence is favored because the orbital rims provide the most accurate guidance for restoration of the internal orbital architecture.

#### **Box 57.8 The Surgical Objectives for Type I Fractures**


Figures 57.28a−d and 57.29a−d demonstrate a type I fracture managed using the above principles.

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**Fig. 57.28** 3D CT scans of patient with orbito-zygomatic fracture. (**a** and **b**) Preoperative frontal and basal views demonstrating the fracture, (**c** and **d**) postoperative frontal and basal views demonstrating fxation of fractures

**Fig. 57.29** Axial and sagittal scans of the patient in Fig 57.28, with orbito-zygomatic fracture. (**a** and **b**) Sections demonstrating fracture of the left zygomatic complex with a large defect of the orbital foor. (**c** and **d**) Post-operative sections revealing optimal reduction of the fracture and foor reconstruction with anatomical orbital foor implant

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#### **57.8.2 Type II (Internal Orbital)**

Management of type II orbital fractures, which are essentially the internal fractures (both blow-in and blowout) of the orbit including (1) the roof, (2) the foor, and (3) the medial and (4) lateral walls are detailed below.

**Box 57.9 The Management of All Internal Orbital Fractures Can Be Handled Essentially by Answering the Following Basic Questions** *(Clinical Tip)*


#### **57.8.2.1 Fractures of the Orbital Roof**

Isolated fractures of the orbital roof are extremely rare. They usually occur as a part of fronto-basilar fractures, fractures of the frontal sinus, or may occur concomitant with fractures of the supraorbital rim. Orbital roof fractures are present in approximately 5% of all orbital and cranial fractures, while incidence of isolated orbital roof fractures may be as low as 0.7% of all orbital and cranial fractures. The most common etiological factors include motor vehicle accidents, assaults, or falls.

Orbital roof fractures may be associated with more severe neurological symptoms including dural tears, CSF leak, tension pneumocephalus, diffuse cerebral edema, and contusions of the frontal lobe [42]. It is imperative for a neurological and ophthalmological consult prior to management.

In general, orbital roof fractures may be categorized into four types (Fig. 57.30).

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and may often be associated with severe neurological implications.

Less than 10% of orbital roof fractures may need any form of surgical intervention [42]. Most are amenable to conservative management with observation and follow-up of neurological and ophthalmic status.

The need for management of fractures of the orbital roof may depend on:


Interventions may be indicated immediately or late primary depending on the indications mentioned above. Reconstruction of the roof of the orbit is not a procedure routinely indicated. However in cases where there is an absolute necessity for reconstruction like prevention of brain herniation or restoration of intra orbital volume which has been signifcantly altered, the choice may vary between the use of titanium meshes (Fig. 57.31) or porous polyethylene implants fxed with micro-screws to split calvarial grafts.

Figure 57.32a−f demonstrates the management of a malunited fronto-basilar fracture along with a blow-in fracture of the orbital roof compressing the eyeball producing restriction of movement.

#### **57.8.2.2 Fractures of the Lateral Orbital Wall**

Lateral orbital walls are the strongest of all the orbital walls [43]. The lateral wall generally shows diastasis and dis-

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**Fig. 57.31** Reconstruction of complex defect of the frontal bone, orbital roof, and supraorbital rim with a titanium mesh

placement in the case of fractures involving the zygomatico-orbital complex and is restored to its normal anatomy when the reduction of the zygomatic complex is achieved [44]. However this wall gets comminuted in highvelocity injuries [45] necessitating reconstruction in the primary intervention.

The anatomy of the lateral wall plays an important role in the internal orbital volume as demonstrated by development of enophthalmos in unrestored lateral wall fractures [46]. Restoration of the architecture or augmentation of the same ensures correction of enophthalmos.

Reconstruction of the lateral orbital walls is usually accomplished with the use of:


Figure 57.33a, b demonstrates the management of fracture of the lateral walls of the orbit in a patient with concomitant fracture of the zygomatic complex.

#### **57.8.2.3 Medial Wall Fractures**

The medial wall and the foor are the thinnest walls of the orbit and have the propensity to fracture the most [47, 48]. Though the incidence of concomitant fractures of the medial wall with that of the orbital foor have been reported over a wide range of 5–71%, its occurrence in isolation is very rare. Most fractures of the medial wall are incidental fndings when CT scans are obtained to study other cranial, facial, or orbital fractures.

The most common type of clinical presentation would either involve a combination of the medial wall and foor (36%) or medial wall, foor, and zygomatic complex (28%) [49–51].

Fractures of the medial wall were managed conservatively in the past, but current literature proposes clear indications [49–51] for the exploration and reconstruction of the medial wall fractures and defects, which include:


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**Fig. 57.32** CT images of patient with malunited fractures of the orbital roof. (**a**–**c**) Pre-operative images demonstrating malunited fracture of the frontal bone and orbital roof of the left side with decrease in intraorbital volume and compression on the globe. (**d**–**f**) Post-operative images showing recontouring of the supraorbital rim and roof using ultrasonic aspirator system, with resultant expansion of the intra-orbital volume

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**Fig. 57.33** CT scan images of lateral orbital wall with concomitant fracture of the zygomatic complex. (**a**) Pre-operative image showing fracture and displacement of the lateral wall and (**b**) post-operative

image showing reduction of the lateral wall and re-establishment of the sphenozygomatic suture continuity

#### **Box 57.10 A Clinically Useful Classifcation of Medial Wall Fractures Has Been Described by Nolasco et al.** [47] **in 1995 Based on CT Scan Findings**

They describe four patterns of presentations (Fig. 57.34)


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**Fig. 57.34** CT scans showing types of medial wall fractures. (**a**) Isolated medial wall fracture; (**b**) fracture of medial wall with foor; (**c**) fracture involving medial wall, foor and zygomatic complex; and (**d**) concomitant fractures of the medial wall, foor, and midface at LeFort 3 level

Contrary to earlier belief the loss of medial wall integrity also signifcantly contributes to development of enophthalmos [49]—with any defect involving an area of more than 1.9 cm2 or volume expansion of excess of 0.9 ml [50, 51] producing clinically signifcant enophthalmos (2 mm or more).

Approaches to the medial wall have already been described in detail earlier. The most favored being the transcaruncular/retro-caruncular approaches which give excellent exposure and access to the medial wall for both exploration and reconstruction [37, 52].

Options for reconstruction include a multitude of materials which may be autogenous or alloplastic as shown in Table 57.1. Bioactive resorbable sheets are also found to produce good outcomes [53].

Figure 57.35a, b demonstrates reconstruction of a medial wall fracture with a Titanium mesh.

#### **57.8.2.4 Orbital Floor Fractures**

The fractures involving the orbital foor are the most common fractures of the internal orbit either in isolation or concomitant with other facial fractures. A comprehensive classifcation of foor fractures with clinical guidelines for management is described by Jaquiery [54] et al. which lays emphasis on the morphology of the defect and the role of the infero-medial strut of the inferior orbital fssure.

The internal orbit is divided into three zones which helps in evaluating the diffculty of approach and exposure:



**Table 57.1** Commonly used biomaterials for orbital reconstructions

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**Fig. 57.35** CT images of patient with medial wall fracture. (**a**) Fracture of the medial orbital wall of the left orbit showing displaced medial rectus. (**b**) Post-operative image demonstrating medial orbital reconstruction with titanium mesh

**Table 57.2** The classifcation of orbital wall defects (Jaquiery et al. modifed by Dubois et al.) [53–55]


The fractures themselves are then classifed into four categories of defects (Table 57.2; Fig. 57.36a−d).

#### **Which Fractures of the Orbital Floor Need Intervention?**

Indications and contraindications for foor exploration and repair are well defned.

#### **Absolute Indications**


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**Fig. 57.36** Diagrammatic representation of the different types of defects of the orbital foor which indicate the grades of diffculty to reconstruct. (**a**) Type I, (**b**) Type II, (**c**) Type III and (**d**) Type IV

A. Parameswaran et al.

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**Fig. 57.37** CT scan images of a young boy with history of orbital trauma. (**a**) Sagittal and (**b**) coronal sections demonstrating a "springing trapdoor" fracture of the orbital foor on the left side with entrapped

inferior rectus muscle. (Courtesy: Dept of Orbit & Oculoplasty, Shankara Nethralaya, Chennai)

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**Fig. 57.38** Clinical photographs of a boy with "White eye blowout" fracture, showing restriction of ocular motility in the left eye in the superior (**a**) and inferior (**e**) gazes. The other gazes (**b**, **c** and **d**) show no abnormalities. (Courtesy: Dept of Orbit & Oculoplasty, Shankara Nethralaya, Chennai)

3. "White eye blowout" fracture in a child or young adult with severe restriction of ocular motility (Figs. 57.37a, b and 57.38) and vagal symptoms.

#### **Relative Indications**


#### **Relative Contraindications**


Figure 57.40a−f demonstrates the delayed management of a patient with an isolated fracture of the foor and medial walls. The CT scan shows fbrosis and adhesion of the inferior rectus muscle to the residual posterior ledge producing diplopia and restriction in superior gaze.

#### **Surgery for Special Indications in Orbital Floor Fractures**

#### **Enophthalmos**

Enophthalmos is the displacement of the eyeball in a posterior direction and is attributed to increase in the intraorbital volume. Numerous studies have shown that there is a correlation between increase in intra-orbital volume and the presenting enophthalmos. It is proved that an increase in intra-orbital volume by 0.5–1 cc would produce posterior displacement of the globe by 1 mm. Enophthalmos of 2 mm or more may be clinically perceivable and warrant surgical intervention [58, 59]. An important aspect of orbital reconstruction lies in the fact that it is the only fracture in CMF region where the onus is not in recreating the anatomical form but rather in the restitution of the intra-orbital volume. Care should be taken to reconstruct the posteromedial aspect of the orbit (Hammer's key area) to achieve anterior projection of the globe. It is imperative to understand that reconstruction of the foor posterior to the equator of the globe infuences anterior projection of the globe, while reconstruction of the equatorial region of the foor infuences only the supero-inferior position of the globe (Fig. 57.41).

Figure 57.42a−d shows a case of delayed correction of enophthalmos in a patient with an orbital foor fracture.

#### **Hypophthalmos**

This is otherwise called hypoglobus and signifes the downward displacement of the globe due to the interruption in the anatomical integrity of the orbital foor. The clinical presence of hypoglobus needs to be differentiated from orbital dystopia which essentially means that the entire bony orbit with its contents is displaced caudally, unlike hypophthalmos, where only the globe is displaced caudally.

However decision-making for surgical intervention based on both enophthalmos and hypophthalmos is challenging as they may or may not present immediately following trauma. (Refer to clinical scenario 1. Figs. 57.57, 57.58 and 57.59).

#### **Diplopia**

Clinically demonstrable double vision is termed diplopia. Generally post-traumatic diplopia due to edema and hemorrhage is self-limiting and shows spontaneous resolution.

section CT demonstrating large defect of the orbital foor. (**b**) Sagittal section CT demonstrating fbrosis and adhesion of the inferior rectus (yellow arrow) to the posterior ledge of the orbital defect

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**Fig. 57.40** CT scan images of patient with internal orbital fracture. (**a**–**c**) 3D, coronal, and sagittal images demonstrating isolated fracture of the left orbital foor and medial wall. (**d**–**f**) post-operative images demonstrating reconstruction of the defect with anatomical orbital implant

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**Fig. 57.41** Graphical representation of the equator of the globe (E) and the associated equatorial (A) and post-equatorial (B) zones of the foor

Diplopia can manifest in two forms:


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**Fig. 57.42** Clinical photographs of patient with enophthalmos. (**a** and **b**) Pre-operative pictures demonstrating signifcant enophthalmos of the left globe. (**c** and **d**) Post-operative pictures demonstrating good surgical outcome

herniations or atrophy of periorbital fat, which do not mandate immediate intervention. Refer to clinical scenario 2.

#### **When Is the Right Time to Intervene?**

The timing for intervention for fractures of the orbital foor can be divided into three categories—immediate, early, and late. The indication for all three categories are well discussed in literature [57] and are listed in Fig. 57.43.

Indications for immediate repair are of an urgent nature and may require priority as surgical emergencies, generally less than 6 h following trauma.

#### **What to Use for Reconstruction of the Orbital Defect?**

A plethora of material both autogenous and alloplastic have been used and documented. A table is provided with the list of the most commonly used materials and their relative merits (Table 57.1). However, contemporary literature favors the use of stock titanium meshes and custom patient specifc implants which provide optimal corrections (Fig. 57.44a, b).

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**Fig. 57.43** Chart showing timing for intervention for orbital reconstruction

#### **Guidelines for Deep Orbital Dissection**

The dissection of the deep orbit is always a challenge for the surgeon due to the high concentration of vital structures within a limited space [60]. A few anatomical landmarks that have been suggested for guidance while dissecting in the deep orbit include:


the medial strut of the inferior orbital fssure is an important entity to identify and utilize for reconstruction of the internal orbit.


**Fig. 57.44** Photographs of (**a**) StrykerR preformed anatomical orbital foor implant and (**b**) titanium "patient-specifc implant" (PSI)


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**Fig. 57.45** (**a**) Demonstration of landmarks on dry skull. (A) Perpendicular plate of the palatine bone. (B) Medial lip of the greater wing of the sphenoid. (C) Orbital confuence and (O) Optic foramen.

(**b**) Intraoperative photograph demonstrating the structures of the deep orbit in a patient undergoing secondary surgery for foor reconstruction with implant replacement

**Fig. 57.46** Photographs showing globe protection devices. (**a**) StrykerR globe retractor, (**b**) SynthesR globe retractor and (**c**) SynthesR retractor in anatomical position demonstrating the use of calibration to aid intraoperatively

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#### **De-herniation of the Orbital Contents and Locating the Posterior Ledge**

Two important aspects of foor reconstruction are:


However, locating the posterior ledge in large defects and secondary corrections may be a signifcant challenge. Absence of posterior ledge in severe orbital trauma is an indication for cantilevered implants which are secured to the infra-orbital rim alone.

#### **57.8.3 Type III (Naso-Orbito-Ethmoid Type)**  (Refer Chap. 58)

The NOE-type fractures are the most challenging of all the orbital fractures to manage in terms of achieving predictable results. The management of the NOE complex reconstitutes the facial form of the central midface: a key element in facial esthetics. This type is also prone to have concomitant injuries to the lacrimal system which should be identifed and treated.

Figure 57.49a−f demonstrates the CT images of a patient with a residual deformity following pan-facial trauma with a right-sided type I NOE and neglected orbital foor fractures.

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**Fig. 57.48** (**a** and **b**) Pre-operative coronal and sagittal section CT images demonstrating the location of the posterior ledge of the foor defect. (**c** and **d**) Post-operative images showing the placement of the anatomical orbital foor implant in the appropriate position to bridge the defect

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**Fig. 57.49** CT scan images of patient with type I NOE fracture, plus orbito-zygomatic complex on the right side. (**a**–**c**) 3D, coronal and sagittal images demonstrating the fractures and the foor defect. (**d**–**f**) Post-

operative images demonstrating ORIF of the right NOE fracture, redo of the orbito-zygomatic complex and foor reconstruction with anatomical orbital implant

#### **Box 57.11 The** *Key Elements* **for Managing Type III Fractures**


#### **57.8.4 Type IV (Complex Fractures of the Face with Orbital Fractures)**

This type includes all the combinations of the fractures of the face which do not fall into the types described above. Sequencing of fractures (refer Chap. 60) such as these including pan-facial fractures requires a thorough understanding of the principles to obtain optimal outcomes. It is to be borne that sequencing and fxation of all facial fractures need to be completed prior to the reconstruction of the internal orbit.

Figures 57.50a−d and 57.51a−d demonstrate a patient with residual facial deformity following RTA. Patient had sub-optimally treated pan-facial and orbital fractures and a malunited mandible fracture. He was operated for a revision surgery addressing his midface and dental occlusion.

### **57.9 Management of Orbital Emergencies**


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**Fig. 57.50** 3D CT images of patient with neglected pan facial injury and associated orbital fracture. (**a** and **b**) Images demonstrating frontal and lateral views showing malunited pan-facial fracture with facial deformity and signifcant dental malocclusion. (**c** and **d**) Post-operative images demonstrating ORIF of the right orbito-zygomatic complex and a Lefort I osteotomy with restoration of skeletal form, midface projection, and restoration of functional occlusion

dose of 30 mg/Kg body weight of methyl prednisolone followed by 3 mg/Kg/h for 24 h) within the frst 8 h of injury, in cases of severe primary vision loss or progressive vision loss.

(c) *Compartment syndromes*: this includes both superior orbital fssure and orbital apex syndromes. The current protocols indicate early surgical decompression where indicated. The role of steroids is debatable as indicated above.

#### **57.10 Pediatric Considerations**  (Figs. 57.52a–d and 57.53a, b)

Pediatric consideration in orbital trauma necessitates the discussion of four important aspects which clearly delineate the management principles from adults.

#### (a) *Ratio of cranium to facial fractures in children*

The face to cranium ratio of an infant is 1:8, while that of a child who is between 4 and 6 is about 1:4. This clearly establishes the fact that the cranium in an infant or a child is much larger than the face and is more exposed to potential trauma. The incidence of orbital roof fractures is much more common in children who are younger than 5 years, while beyond the age of 7, the foor fracture is more commonly seen.

(b) *Pediatric orbital roof fractures*

Roof fractures in children occur in the growing age [68] and cause an entity called the "growing skull fracture," where the fracture fragments continue to separate due to growth, causing "leptomeningeal" herniation which involves herniation of the meninges and part of the frontal lobe into the orbital cavity. Management of these need to be planned in conjunction with neurosurgical support.

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**Fig. 57.51** Coronal and axial CT images of the patient in Fig 57.50. (**a** and **b**) Images demonstrating comminuted fractures of the midface and orbit. (**c** and **d**) Post-operative images showing optimal restoration of form of the face and orbit

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**Fig. 57.52** Clinical photographs of a 6-year-old child with left sided orbital trauma (**a** and **c**) frontal and basal views demonstrating immediateonset enophthalmos and hypophthalmos. (**b** and **d**) post-operative photographs showing optimal post-surgical outcome. (Courtesy: Dept of Orbit & Oculoplasty, Shankara Nethralaya, Chennai)

**Fig. 57.53** CT scan images (**a**) 3D image demonstrating fracture involving the left infra-orbital rim and orbital foor in a 6 year-old child, (**b**) sagittal sections of both orbits showing left sided foor fracture. (Courtesy: Dept of Orbit & Oculoplasty, Shankara Nethralaya, Chennai)

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(c) *White eye blowout*

The presence of foor fractures with restriction in superior gaze, with or without oculo-vagal responses and devoid of any physical signs of hemorrhage or ecchymosis in the eye or periorbital region [69–71]. This is a feature which may be seen in children and young adults as a result of a "self-reducing trapdoor" fracture which entraps the inferior rectus. The white eye blowout is considered a surgical emergency and necessitates immediate intervention.

(d) *Role of resorbable implants*

The cranium and upper face exhibit rapid growth in the early years. The orbit completes almost 80% of its growth within the frst 2 years of life and another 10% within the next 2–3 years. Choice of implants in the growing orbit is to be taken into consideration by the surgeon who has to plan for the residual growth of the orbit and possible chances of migration of implants.

### **57.11 Secondary Correction of Orbital Deformities**

Secondary corrections of the internal orbit demand great degrees of skill and are technically demanding even for the trained surgeon due to the nature of fbrosis and contracture that is already set in and the distortion of bony landmarks within the orbit. This may necessitate more extensive dissection and mobilization of the orbital contents and yet yield sub-optimal outcomes.

### **57.12 Complications**

Complications associated with management of orbital fractures may be categorized into immediate and delayed complications.

#### **Box 57.12 Indications for Secondary Deformity Correction of the Internal Orbit Generally Are**


#### **57.12.1 Immediate Complications**

The most common immediate complications that are secondary to orbital surgery include:


Hemorrhage may be an infrequent complication which may happen during the surgery or in the immediate postoperative period.

Complications associated with specifc ophthalmic implications like injuries to the cornea, extraocular muscles, lacrimal apparatus, or the optic nerve also may occur.

Blindness is a rare but grievous complication which has to be borne in mind.

The last group includes neurosensory disturbances like paresthesia or dysesthesia associated with the infra-orbital nerve and carrying grades of facial nerve palsy or weakness [72, 73].

#### **57.12.2 Delayed Complications**

Delayed complication may present in the form of:


Other adverse outcomes include:


#### **57.13 Recent Advances in Management of Orbital Fractures**

Orbital reconstruction still remains one of the most challenging and enigmatic areas in the management of cranio-facial trauma and most certainly attracts the latest in terms of technology and developments to refne and improve outcomes. Signifcant advances in the feld of orbital reconstruction include:


#### **57.13.1 Navigation and CAS for Orbital Fractures and Reconstruction**

Computer-assisted surgery allows virtual pre-operative planning of the desired reconstruction using pre-operative CT scans (Fig. 57.54a−d) [74]. This virtual plan gives realtime guidance during surgery. Navigation helps visualize the actual surgical outcome during surgery in relation to the pre-operative plan (Fig. 57.55). With this technique, sub-optimal reduction of fractures and positioning of implants can be identifed and corrected during surgery, thereby reducing the need for secondary procedures [75–77].

#### **57.13.2 Patient-Specifc Implants**  (Fig. 57.56a–c)

Custom implants for the reconstruction of complex defects and deformities have become vogue now. They offer the advantages of accurate planning and infallible positioning intraoperatively which enormously improve post-surgical

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 57.54** Photographs depicting stages in computer-assisted surgery for orbito-facial reconstruction. (**a**) Generation of virtual 3D model; (**b**) segmentation and mirroring of normal side; (**c**) superimposition of the mirrored object on the affected side, enabling a better understanding of the deformity; and (**d**) creation of patient specifc implant design for the fronto-zygomatic region and importing the virtual model of the anatomical orbital implant for foor reconstruction

outcomes. The defect can be mapped digitally and a construct can be made after virtual surgical planning to aid in intraoperative guidance. The implants may also function as guidance stents and double up as fxation devices too.

#### **57.14 Conclusion**

To conclude, all patients with orbital trauma need to be subjected to ophthalmological examinations both pre- and post-surgery. Globe protection, gentle retraction of tissues, and intraoperative testing for vision are mandatory during orbital surgery.

#### **Box 57.13 Principles to Be Followed During Surgery for Orbital Floor Reconstruction**


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**Fig. 57.55** Screenshot images of a left-sided orbital foor with an anatomical orbital foor implant that is virtually planned and executed with the help of intraoperative navigation

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**Fig. 57.56** PSI designed for reconstruction of a large foor and medial wall defect in the right orbit. (**a**) Frontal view of PSI on an STL model of the patient, (**b**) superior view, and (**c**) intraoperative photograph showing placement of the PSI "in situ"

#### **57.15 Case Scenarios**

#### **Case 1**

Patient with a history of facial trauma 8 months back presented with complaints of change in the position of his eyeballs. He had a history of surgical intervention for management of his pan-facial fractures immediately following the trauma. No intervention was performed for the orbital fractures primarily. Subsequent clinical evaluation performed 8 months later revealed enophthamos, hypophtalmos and restriction in superior gaze in the right eye. CT scans revealed a large orbital foor defect on the right side with fbrosis and adhesion of the inferior rectus to the posterior ledge of the foor defect. The patient was subjected to secondary surgery for correction of the above mentioned complaints. An orbital exploration was performed on the right side to release the inferior rectus, the infra-orbtial rim was augmented with a ramal graft and the foor defect was reconstructed with a "Stryker" anatomical orbital implant. Post-surgical evaluation revealed optimal corrections of the enophthalmos, hypophthalmos and good repositioning of the inferior rectus muscle (Figs. 57.57a−d, 57.58a, b and 57.59a−f).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 57.57** (**a** and **b**) Pre-operative clinical photographs of patient demonstrating right sided enophthalmos and hypophthalmos. (**c** and **d**) Post-operative clinical photographs showing optimal surgical outcomes

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**Fig. 57.58** 3D CT reconstructions of patient in Fig 57.57 demonstrating (**a**) right-sided malunited zygomatic complex fracture with orbital foor defect and (**b**) post-surgical scan image showing reconstruction of the right orbital foor defect with an anatomical orbital implant after augmentation of the infra-orbital rim with a mandibular ramus bone graft

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 57.59** (**a**–**c**) Pre-operative axial, coronal, and sagittal scans of patient in Fig 57.57 with large defect of the right orbital foor. (**d**–**f**) Postoperative sections demonstrating the correction of the foor defect with an anatomical orbital implant

#### **Case 2**

A 12 year old girl presented to the surgical OPD with history of blunt injury to the left eye. On examination she had no external signs of injury but revealed restriction in superior gaze in the left eye. CT scan revealed a springing trapdoor fracture of the left orbital foor with entrapment of the inferior rectus muscle. A diplopia charting was performed which revealed moderate to severe restriction of the left eye in the superior gaze. The patient was taken up for immediate surgery for orbital exploration and release of the entrapped muscle with/without foor reconstruction. The exploration was successful and the patient required no reconstruction of the foor. Post operatively the patient demonstrated complete resolution of the symptoms with the full range of ocular movements restored. (Figs. 57.60, 57.61, 57.62a, b) (Courtesy: Dept of Orbit & Oculoplasty, Shankara Nethralaya, Chennai)

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**Fig. 57.60** Pre-operative photograph demonstrating the nine gazes of a young girl with a "White eye blowout" fracture of the left orbital foor with entrapment of the inferior rectus. (Courtesy: Dept of Orbit & Oculoplasty, Shankara Nethralaya, Chennai)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 57.61** Post-operative photograph demonstrating resolution of symptoms after 3 weeks of surgery (Courtesy: Dept of Orbit & Oculoplasty, Shankara Nethralaya, Chennai)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 57.62** Photograph of documentation of diplopia by charting with two colors (green for left and red for right eyes). The left and right sides are marked in the orientation that the patient sees an object in front of him/her. (**a**) Pre-operative and (**b**) post-operative (Courtesy: Dept of Orbit & Oculoplasty, Shankara Nethralaya, Chennai)

#### **References**


zygomatico-orbital complex fracture reduction. J Oral Maxillofac Surg. 2013;71(5):894–910.

77. Wilde F, Schramm A. Intraoperative imaging in orbital and midface reconstruction. Facial Plast Surg. 2014;30(05):545–53.

#### **Additional Reading**

Bater MC, Ramchandani PL, Brennan PA. Post-traumatic eye observations. Br J Oral Maxillofac Surg. 2005;43(5):410–6.

**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Frontal and Naso-Orbito-Ethmoid Complex Fractures**

**58**

Kannan Balaraman

#### **58.1 Introduction**

Naso-orbito-ethmoid (NOE) region is a confuence of critical structures of the face including the nose, orbit and skull base. Hence injuries to the region have a major impact on the function of these regions as well as aesthetics. A deformity of the NOE region tends to catch the eye much more than a deformity elsewhere in the face and hence affecting the individual. The injuries to this area are about 5% of maxillofacial injuries in adults and about 15% in children [1, 2] and mostly occur as a result of road traffc accidents (RTA) [1] especially in the Indian subcontinent. This is especially so due to two-wheeler injuries. Considering the proximity of the region to the brain and globe, these injuries may need multidisciplinary evaluation before embarking on a defnitive treatment plan.

#### **58.2 Applied Surgical Anatomy**

The NOE complex is a part of the medial vertical buttress system of the face abutting the cranium. It is made of the nasal bones, the ethmoid bones encompassing the sinuses which also form the medial wall of the orbit articulating above with the frontal bone at the anterior skull base. This ethmoid labyrinth which separates both the orbits acts like a shock absorber during trauma thus minimizing force dissipation into critical structures like the orbital and cranial cavities. Extensive injury or comminution can result in associated anterior cranial base fractures causing cerebrospinal fuid (CSF) leak as well. The frontal process of maxilla and the lacrimal bone also is an integral part of the complex owing to their proximity and involvement in the fracture pattern occurring in the region.

K. Balaraman (\*)

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**Fig. 58.1** MCL anchoring eyelids (O-occular, P-palpebral)

Apart from the bony parts, the medial canthal ligament (MCL) is an important soft tissue of the complex (Fig. 58.1). The ligament not only anchors the upper and lower eyelids to the nasal complex but also encompasses the lacrimal sac at its anterior, posterior and superior aspect [3]. Certain authors have found that the posterior limb is not always present or clearly defned in certain instances [4]. The ligament being attached to the edges of the lacrimal fossa in the lacrimal bone in these areas helps in emptying of the lacrimal sac during blinking thus effecting drainage of the lacrimal sac. Hence injuries to the region affecting the attachment of the medial canthal ligament can impact the medial eyelid attachment and/or draining off tears from lacrimal sac. The skin and soft tissues drape over the complex like a cloth over a framework, and when the region crumples following an injury, the soft tissue envelope collapses as well causing distinct deformity which if not treated well can result in persistent deformity of the region. The collapsed soft tissue heals/ scars over the deformed bony complex and secondary correction at a later date do not help achieve the pre-injury status. Hence optimal primary realignment and repair offer the best chance of achieving optimal results [5].

Department of Oral and Maxillofacial Surgery, Ganga Medical Centre and Hospitals, Coimbatore, Tamil Nadu, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1251

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_58

#### **58.3 Historical Perspective and Classifcation** [6]

The treatment of NOE complex injuries has evolved from the previous century. Though nasal bone fractures have been recognized for a long time, the fracture of ethmoids was highlighted by Dawson and Fordyce in 1953. Converse and Smith in 1963 identifed the involvement of medial orbital wall and termed it as naso-orbital. Stranc was the frst to in modern English literature to adopt the terminology naso-ethmoid. Epker recognized the present-day terminology of nasoorbito-ethmoid in 1973, whilst Gruss in 1985 preferred the term naso-ethmoid-orbital [6].

#### **58.3.1 Classifcation**

Rowe and Williams [7] in their classic text highlighted the complexity of the area and stressed the need for primary management. Their classifcation was quite simple, depending on side involved and association with other fractures.


Markowitz and Manson (1991) [8] identifed the importance of canthal ligament, and their classifcation refected the need for getting the position of the canthal ligament either by manipulating the fragment or anchoring the canthus directly. Their classifcation was as follows (Box 58.1):

#### **Box 58.1 Markowitz and Manson Classifcation**


#### **58.3.2 Paediatric NOE Fractures** (Fig. 58.2) **Classifcation: Burstein et al.'s** [9] (Box 58.2)

## **Box 58.2 Paediatric NOE Fracture Classifcation**

Paediatric NOE fractures classifcation types are:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 58.2** Paediatric NOE fractures classifcation

Markowitz classifcation of adult NOE fractures does not take into account the differences in paediatric population such as:


#### **58.4 Aetiology, Clinical Features and Diagnosis**

The most common aetiology of the fracture of NOE complex is trauma be it road accidents in unprotected individuals, assaults or fall from height [10].

Initial presentation can be disconcerting for the individual and bystanders due to profuse nasal bleeding and gross oedema around the midfacial skeleton. The signs and symptoms are given in Box 58.3 (symptoms) and Box 58.4 (signs).

#### **Box 58.4 Signs of NOE Fracture**



From the point of view of the examining clinician, Advanced Trauma Life Support (ATLS) protocols take precedence however gross the presenting scenario is (Refer Chap. 48 of this book). Once primary survey is completed and the patient cleared for secondary survey, defnitive clinical examination starts. It is also imperative to rule out underlying injuries to the head/brain, ophthalmologic or associated structures prior to comprehensive maxillofacial assessment.

The main indicators suggesting an underlying NOE fractures include:


#### **Measurement of Intercanthal Distance (ICD):**

Normal values are 32–33 mm for females and 33–34 mm for males. The rule of thirds can be applied whilst evaluating NOE fractures. Normally ICD equals the palpebral fssure width. However, in NOE fractures, increased ICD is found, called telecanthus (Fig. 58.5).

Telecanthus deformity is characteristic; the lateral displacement of MCT leads to rounding of the medial palpebral fssure, widening of the NOE region and transverse shortening of the palpebral aperture.

• Care should be taken to rule out CSF leak and also damage to the nasolacrimal duct. However the latter is diffcult to assess primarily in some of the cases and may become apparent much later. Clear discharge from the nose or watery bloody discharge should arouse a high index of suspicion necessitating further biochemical investigations to differentiate CSF from nasal discharge. Glucose content is more in CSF, but assessment of Tau protein (beta 2 Transferrin) is the confrmatory diagnostic factor. Thorough neurologic and ophthalmologic assessment is also essential. In the acute setting, clinical examination is challenging due to the discomfort and

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 58.3** (**a**, **b**) Depressed, widened nasal complex with upturned tip of the nose

always may be inadequate [11, 12], and hence radiological investigations are mandatory. The diagnosis and understanding of the fractures has evolved over the last century with the advent of CT imaging. CT scan imaging in all planes is the norm in these fractures and helps in ruling injuries to the adjacent structures as well as assess-

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**Fig. 58.4** Bowstring test for assessment of MCL attachment patency

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**Fig. 58.5** Traumatic telecanthus

ing the extent and nature of displacement of NOE complex injuries.

• High-resolution CT scan images in all planes (axial, coronal (Fig. 58.6a–d)) help to identify and assess the fracture pattern accurately. Thin sections (0.6 mm) not only help in better evaluation but also facilitate surgical planning or fabrication of models if required. The CT scans will be mandatory anyway to assess the head injury status in such cases, and these images can be a part of the head injury screening imaging. Communicating with the radiology department of the importance of such images will ensure that the required sections being done at the same instance of head injury assessment scans thus avoiding repeat scans. The axial sections show if there is disruption of the nasal complex or there is splaying of the ethmoid complex. The coronal sections depicts the displacement in the mediolateral aspect (thus the status of the fragment with the MCL), whilst the sagittal sections

©Association of Oral and Maxillofacial Surgeons of India **Fig. 58.6** (**a**–**d**) Axial and coronal CT scan images of NOE fracture

depict the displacement in the anteroposterior (AP) aspect (depression).

• 3D reconstructed images show the gross morphologic status and are as accurate as the thinness of the sections. Such images are good to plan the surgical management, discuss with the assistants the treatment goals and also explain to the patient the nature of the injury and proposed treatment plan as part of informed consent.

#### **Test to Assess Integrity of MCT**

NOE fracture is positive if mobility of the medial canthal tendon is appreciated.

It is revealed by a Bowstring or a bimanual test.

• Bowstring Test:

When the eyelid is pulled laterally, a lack of resistance or detection of movement of the underlying bone at the tendon area is indicative of a fracture.

• Bimanual Test:

An instrument is placed in the nose and pushed laterally. Instability and crepitation felt at the tendon area suggests NOE fracture.

#### **58.5 Management**

The initial presentation of such patients occasionally may be dramatic due to profuse epistaxis which may exacerbate in someone lying down. Keeping patients sitting up with packs in the anterior nostril might help reduce the bleed. Persistent profuse bleed may necessitate intubation to secure the airway and packs in both anterior and posterior nasal passages to help prevent aspiration.

The patient once stabilized, and ft to undergo surgery will need a discussion with the anaesthesiologist about options of intubation. Fractures not involving occlusion can be managed by oral intubation, whilst if involving occlusion then options like submental intubation or even tracheostomy of the patient requires prolonged ventilation or due to have further surgical procedures (as in poly trauma patients).

The presence of CSF leak might pose a tricky problem. Instances of CSF leak are higher whenever there is pneumocephalus. Hence in such instances, an approach combined with neurosurgical team may be mandatory, whilst involvement of an ophthalmologist is mandatory when there is involvement of lacrimal drainage system or lid adnexa. The treatment goals of NOE are shown in Box 58.5.

#### **Box 58.5 Treatment Goals of NOE Fracture**

Treatment goals

Restoring the nasal projection


Conventionally the nasal complex was treated with closed reduction till Adam et al. [6] reported on the importance of nasal wiring. The importance of involving the medial canthal region in the treatment plan was initiated by Converse and Smith in 1963 [6]. They emphasized the importance of manipulating the segment with the MCL, forward positioning the fragment and trans nasal wiring over a perforated plate.

The case for open reduction and internal fxation (ORIF) was highlighted by Dingman and Natvig [13]. They reported superior results have been achieved in the more serious injuries (with minimum of effort and with the greatest degree of comfort to the patient) by open reduction with direct fxation. The need and feasibility of identifying MCL and anchoring it across to the other side was described by Mustarde in 1964 [14]. The need for primarily bone grafting when there is severe comminution of the nasal dorsum rendering primary reduction incomplete and also help achieve single-stage reconstruction was highlighted by Cruse [15] and Gruss [16].

Reduction of the nasal complex may be done with Walsham's forceps to realign the deviated/displaced complex. The collapsed complex may be out-fractured, and complex opened out may need to be in-fractured. The depressed complex may be elevated into position by the septal forceps (Ash's). However in displaced or comminuted scenarios, closed reduction isn't optimal. Hence trans nasal wiring may be needed to keep the splayed segments well reduced and minimize telecanthus. In the absence of gross comminution, closed reduction and trans nasal wiring has been proved quite useful and adequate to achieve optimal results as advocated by some authors especially in patients with associated maxillary fractures [17].

#### **58.5.1 Surgical Access for NOE**


Ed Ellis et al. [11] reported on having a sequential plan to proceed with the surgical sequence. They emphasized on adequate exposure for identifcation of the bone fragment with the MCL tendon, realigning the medial rim and canthopexy if required. The nasal dorsum reconstruction is planned at the end.

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 58.9** Bicoronal approach

According to them pre-treatment photographs are very important in getting good results, and deformity should be overtreated than undertreated because secondary deformity which occurs is diffcult to treat.

#### **Trans nasal wiring:**

Closed reduction in established fractures with telecanthus rarely helps achieve adequate reduction and MCL reposi-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 58.8** Glabella approach

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**Fig. 58.10** Butterfy incision (combination of Gullwing and open sky incision)

#### **Steps in Management**


tioning and hence may need trans nasal wiring as well to help with MCL positioning [6, 13]. Using a K wire driver or an awl will help pass a trans nasal wire across the nasal complex and help narrow the area by bringing the sides together. To help achieve adequate narrowing and restore

©Association of Oral and Maxillofacial Surgeons of India

**Fig 58.11** Vertical incision

the canthal distance, the entry area on the affected site should be just superior and posterior to the posterior lacrimal crest to which the posterior limb of the ligament is attached. The wire entry point anterior to the area can result in widening of the telecanthus as the posterior aspect fares laterally.

As long as a large fragment with MCL attachment is identifable, open reduction and fxation of the fragment can help in achieving our objectives. Using very low profle titanium plates (1.1–1.3 mm depending on the system used) helps achieve adequate fxation. Rigid fxation needs exposure of a stable area to help achieve the same and may necessitate exposing the glabella or frontal bone superior to it for adequate results. Realignment of the fragments and fxation will help in achieving better results in cases of fracture having multiple fragments and reconstruction with bone graft wherever required (Fig. 58.13 a, b).

MCL disruption or a tiny bony fragment with MCL might necessitate a canthopexy.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 58.12** H shaped incision

#### **58.5.2 Trans Nasal Canthopexy**

The objectives of trans nasal canthopexy are:


The commonly used methods are the trans nasal wiring (Fig. 58.14) or using a canthal barb. The identifed ligament edges are either anchored with a suture (size 2–0 prolene) or a wire (26 gauge) and guided to the opposite side. The entry point is posterior and superior to lacrimal crest to ensure adequate positioning. One way to help achieve this is to adapt a plate in medial aspect extending from lateral nose onto the medial wall extending just beyond the lacrimal crest (Fig. 58.15).

The wire or suture anchoring the MCL is passed through a hole of the plate just beyond the lacrimal crest brought to

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 58.13** (**a**) Alignment and fxation of stable fragments. (**b**) Bone grafting of the dorsum of nose

the opposite side and secured around a screw in the forehead adjacent to the midline or a plate to prevent the wire cutting through the bone. Special barbed wires have been advocated by certain authors to engage the MCL and anchor it to help with medial canthopexy with small incisions around the medial canthus. These help especially when there is medial canthal disruption without bony disruption [18, 19].

Figure 58.16 shows a clinical case where the MCL has be anchored to the holes of the plate on either sides (arrows) with SS wires.

Paediatric injuries of the naso-maxillary complex are generally under treated, but they need similar management protocols like that of an adult to achieve optimal results [20]. The use of resorbable implants will be of prudence in the paediatric patients [3].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 58.14** Canthopexy with SS wire (note the wire shown as dotted lines)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 58.15** Use of plate to guide MCL reattachment (note the MCL fxed to plate with a wire, the red lines denote the fractured bones)

Post-operative aesthetic assessments of outcomes done for the management options comparing the canthal position and nasofrontal angle measurements have indicated that bone grafting may result in obtunded nasofrontal angle as compared to ORIF. Closed reduction of the complex has resulted in under projection of the nasal bridge region [20].

#### **58.5.3 Soft Tissue Readaptation**

A post-operative nasal bolster splint is very important after ORIF or NOE fractures. It plays the following functions:

• It reduces post-operative swelling due to oedema and haematoma.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 58.16** shows a clinical case where the MCL has been anchored to the holes of the plate (blue arrow) on either sides with SS wires (yellow arrow)

Redrapes soft tissues to underlying skeletal framework and prevents *pseudo telecanthus* (increase in intercanthal distance, in spite of accurate reduction and fxation of facture fragments. This occurs due to non-adaptation of soft tissues to the underlying NOE complex, with resultant fbrosis of tissues). *Bolster splints may cause skin necrosis if used inappropriately*. After reduction and fxation of NOE, nasal packing has been done with ribbon gauge soaked in paraffn/ favine emulsion or bismuth iodoform paraffn paste (BIPP). Over packing should be avoided. Sometimes it obstructs the airway and a potential source of infection and required removal after 72 h postsurgery.

#### **58.5.4 Post-operative Evaluation** [20]

It includes evaluation of:


The average distance between the medial canthus should be approximately 1/3rd (33%) of the distance between lateral canthus. The distance from the lateral canthus of the eye to cornea and cornea to nasofrontal junction will be compared, and they should be in 1:1 relationship. The ideal naso-orbital angle is approximately 115–130°. All the three parameters

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**Fig. 58.17** Ideal intercanthal distance

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**Fig. 58.18** Ideal nasal projection (1:1)

should be checked post-operatively to assess the surgical results (Figs. 58.17, 58.18, and 58.19).

#### **58.6 Complications**

Inadequate assessment and treatment planning may result in incomplete management of the NOE complex resulting in secondary deformity which can aesthetically inadequate. Deformities of the NOE are quite easily noticeable compared to those in other regions, and hence appropriate management helps achieve good results. The aesthetic issues like persistent telecanthus or depressed nasal bridge are diffcult to correct secondarily with suboptimal results. Hence the frst time is the best time to address the central nasal component [21,

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 58.19** Ideal frontonasal angle

22]. Apart from aesthetic complications, functional issues like epiphora due to nasolacrimal duct injury or obstruction may manifest which may need stenting [23] or dacryocystorhinostomy (creating a osteum in the lateral nasal wall adjacent to the lacrimal sac along with stenting) to establish patency. Involvement of the medial wall may result in diplopia [24] which if not addressed adequately may persist. Another important issue overlooked is anosmia, but if it should occur, recovery is unpredictable, and prior discussion with patients is better. In cases with concomitant brain injuries or CSF leak, risk of associated sequelae is present, and a multidisciplinary approach helps. Though improperly placed trans nasal wires may occlude/impede the lacrimal drainage apparatus, it remains a popular modality to help treat these fractures [25, 26].

#### **58.7 Frontal Sinus Fracture**

#### **58.7.1 Introduction**

Fractures of the frontal sinus are frequently associated with orbital, NOE, nasal and anterior cranial fossa injury. Frontal sinus is most frequently damaged as a result of high velocity motor vehicle accidents. 70% of frontal sinus fractures were due to automobile accidents and 20% due to assaults. Proximity of sinus to the brain makes untreated disease in this area potentially fatal. Inappropriate treatment of frontal sinus fracture can lead to mucocele formation, recurrent sinusitis, osteomyelitis of frontal bone, brain abscess or thrombosis of cavernous sinus, encephalitis, etc. [27].

#### **58.7.2 Applied Anatomy of Frontal Sinus**

Frontal sinuses are two asymmetric sinuses separated by a thin bony septal plate. The average dimensions of frontal sinus are as follows [28]:


The frontal sinus is an air-filled cavity lined by pseudostratified ciliated columnar epithelium encased in bone. It becomes visible radiographically at the age of 6 years. The posterior table is thinner than the anterior table. The posterior table separates the sinus from dura of frontal lobe. Anterior table is covered by a soft tissue layer of frontalis muscle, orbicularis oculi muscle, supraorbital and supratrochlear nerves, vessels and skin. Posteriorly, the floor of the frontal sinus consists of orbital plate of frontal bone. Anteriorly, the floor of the sinus overlies the anterior ethmoidal sinus and nasal cavity. The frontonasal drainage area of the sinus originates from the posteromedial part of sinus floor. The frontal sinus drains through the frontonasal ducts into the middle meatus of the nasal cavity or directly through the ostia into the nasal cavity.

#### **58.7.3 Functions of Frontal Sinus**

Following are the various functions of the frontal sinus:


The diagnosis of the frontal sinus fracture based on the proper history and physical examination of the patient which includes inspection and palpation of the affected area.

*The detailed history includes the following points*:

	- 5. Rhinorrhea
	- 6. Sense of smell
	- 7. Previous history of nasal or sinus disease surgery

#### **58.7.4 Clinical Features** [29]


#### **58.7.5 Radiographic Features**

For an accurate diagnosis of frontal sinus fracture, a CT scan (Fig. 58.20a, b) in different views must be examined [30].

1. Axial view: It reveals location, severity and degree of comminution of anterior and posterior table fractures.

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**Fig. 58.20** (**a**, **b**) 3D CT and axial CT image with frontal sinus fracture


#### **58.7.6 Classifcations**

Frontal sinus fractures are usually classifed based on:


#### **58.7.7 Stanley's Classifcation of Frontal Sinus Fracture** [31]

	- Isolated to anterior table
	- Accompanied by supraorbital rim fracture
	- Accompanied by naso-ethmoid complex fracture
	- It is a linear fracture either on transverse direction or in vertical direction
	- Isolated to both tables
	- Accompanied by naso-ethmoid complex fracture

#### **58.7.8 Gonty Et al. Classifcation of Frontal Sinus Fracture** [32]

	- Isolated to anterior table
	- Accompanied by supraorbital rim fracture
	- Accompanied by naso-ethmoid complex fracture
	- A linear fracture either on transverse direction or in vertical direction
	- Comminuted fracture either isolated to both tables or accompanied by naso-ethmoid complex fracture

#### **58.7.9 Management** (Box 58.6) [33]

#### **Surgical Access:**


#### 1263

#### **Box 58.6 Guiding Principles for Frontal Sinus Management**


#### **58.7.10 Indications of Surgery in Frontal Sinus Fractures** [35]


#### **58.7.11 Management of Anterior Table Fracture** [36–38]

#### **Decision-Making:**


Other than surgical intervention, antibiotics, sinus decongestants and analgesics are prescribed to keep the frontonasal duct patent and to prevent infection.

Rai et al. [39] suggested bone mapping/sketching in management of anterior table frontal sinus fracture with great success. To get good post-operative contour, each fracture fragment is to be placed at the original position after debridement of the sinus. For the same purpose, numbers have to be given to the fracture fragments on a plane paper (sterile glove covering paper) or green sheet (Fig. 58.22a–c).

Yoo MH et al. suggested endoscopic trans nasal reduction of anterior table fracture [40]. To support the reduced frag-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 58.21** Gullwing or eyeglass incision

ments, they advocated use of custom made latex glove balloon to be inserted into the frontal sinus then expanded and maintained for 3 weeks. It avoid use of coronal incision is the advantage of endoscopic reduction. It should be avoided in severe comminuted fractures, displaced posterior table fracture with evidence of dura tear, associated orbital roof blow in fracture and extensive skull bone fractures.

#### **58.7.12 Treatment of Posterior Table Fracture**  [41]

Patients with displaced and comminuted posterior wall combined with or without anterior wall require the support of a neurosurgeon because of dural and intracranial lesions. To get the good exposure, bifrontal craniotomy is indicated to eliminate the posterior wall.

To widen the neurosurgical access to the anterior foor of the cranium, the supraorbital bandeau will be temporarily removed. The sinus mucosa carefully removed with bur, and sinus is cranialized, and then repair of the dura will be carried out. Calvarial bone graft used to obliterate the nasofrontal duct and bone powder can be used to cover the remaining dead space. Anterior table can be stabilized with bone plates and screws. Bone defect will be treated with calvarial bone graft or titanium mesh. With patent duct and no concurrent dural tears or brain injury exist, any amount of posterior table displacement is inconsequential and managed by observation.

#### **58.7.13 Methods of Treatment of Damaged Frontonasal Duct** [42]

The damage to the nasofrontal duct and frontal sinus obstruction increases the risk of mucocele formation and infammatory complications post-operatively. Obliteration of the duct is indicated in such situation. The muscle, temporalis fascia, bone chips, etc. are the materials used commonly to obstruct the duct.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 58.22** (**a**–**c**) Bone mapping/sketching in management of anterior table frontal sinus fracture

#### **Box 58.7 Complications of Frontal Sinus Fractures [46]**


#### **58.7.13.1 Material Used for Sinus Obliteration**  [43]


#### **58.7.14 Cranialization** [44, 45]

It is another technique to minimize the dead space in sinus. It involves removing posterior table thus permitting brain to expand into frontal sinus resulting in confuence between sinus cavity and anterior cranial fossa. It is done in cases with CSF leak and neurological injury due to displaced posterior table fracture. To isolate the splanchnocranium from the frontal sinus, a pericranial fap is used.

#### **58.7.15 Key Points**


tion, slow resorption rate, and it is gradually replaced by the fbrous tissue.

Complications of frontal sinus fractures is given in Box 58.7.

#### **58.8 Conclusion**

The management of NOE and frontal sinus fracture is always a challenging task .The proper handling of MCL and nasofrontal duct is mandatory to get good post-operative results. Proper treatment planning in the form of incision selection, method of fxation and use of bone graft should be done to avoid unaesthetic results.

#### **References**


neogenesis in the cat model. Plast Reconstr Surg. 1995;95(3): 586–92.


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## **Gunshot Injuries of the Maxillofacial Region**

Lt Col Rohit Sharma and Maj Anson Jose

#### **59.1 Introduction**

Gunshot injuries to the maxillofacial region in particular present a challenging situation for the facial reconstructive surgeon. These injuries are relatively rare and hence the true incidence is unknown [1]. Feature common to most maxillofacial gunshot injuries is extensive tissue destruction. The degree of tissue loss, depth of the injury, associated necrosis, and concomitant central nervous system (CNS) injuries may not be apparent at initial presentation [2]. Comprehensive management of such wounds is often challenging because of its heterogeneous nature, composite 3D tissue destruction, and complex structural and functional anatomy of the face.

In contrast to blunt facial trauma, the literature on the management of ballistic facial injury is relatively scarce [1]. The management strategies for patients with facial gunshot wounds are almost as diverse as the case presentation itself. While there has been a gradual shift from conservative delayed operative repair to an early aggressive one-stage management approach, the controversies surrounding the timing and extent of intervention have not yet ceased to exist. Such an ongoing debate is largely due to the fact that the majority of treatment outcomes of gunshot facial injuries continue to be unsatisfactory regardless of treatment methodology adopted. On the other hand, new principles have evolved including the early defnitive repair of hard tissues with precise anatomic rigid fxation using bone grafts and defnitive soft tissue management with local or vascular faps allowing for early rehabilitation of patients to their pretraumatic appearance. This paradigm shift away from delayed to a more immediate defnitive reconstruction has been predominantly due to the widespread use of free tissue

Lt Col R. Sharma (\*)

transfer, diagnostic computed tomography (CT) scan, and deeper understanding about zone of injury in such cases [3].

Presently the management of gunshot injuries comprises the following steps:


This review describes the current management strategies, damage control surgery, and basic protocols employed in the management of high-velocity ballistic injuries to the face.

#### **59.2 Pathologic Anatomy and Classifcation**

Traditionally gunshot injuries have been classifed as penetrating, perforated, or avulsive [7]. As the gamut of injuries continues to evolve, the severity and magnitude of facial ballistic wounds demand an expanded classifcation and can be appropriately classifed based on the wounding effects and terminal location of projectile as:


**59**

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1267

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_59

Department of Oral and Maxillofacial Surgery, 11 Corps Dental Unit, Jalandhar Cantt, India

Maj A. Jose Department of Oral and Maxillofacial Surgery, ADC R&R, New Delhi, India

Penetrating injuries are caused when a low-velocity projectile pierces the tissues without making an exit wound (Fig. 59.1).

On the other hand, perforating injuries are distinguished by the presence of a defnite exit wound in addition to the entry wound (Figs. 59.2 and 59.3). The exit wounds are often larger with ragged or stellate margins. Avulsive injuries are basically penetrating injuries, characterized by an acute loss and destruction of tissue as a consequence of the passage of the projectile within and out of the body (Fig. 59.4). Blast

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 59.1** Penetrating injury with bullet lodged inside the neck

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 59.2** Perforating injury caused by 7.62 × 39 mm AK-47 rife. Note the effects of high-energy bullet impact and explosive effects of cavitation on soft tissues resulting in stellate wound margins at the exit

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 59.3** Avulsive injury of midface caused by a short-range highvelocity impact. The hallmark of high-velocity injuries are comminuted fractures of the facial skeleton with avulsion of soft tissues

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 59.4** "Chop off" injury with complete avulsion of the mandible and associated soft tissue caused by velocity projectile from a military assault rife

injuries are the result of direct or indirect exposure to an explosion caused by military weapons or explosive devises (Fig. 59.5). "Chop off" injuries represent wounds with extensive hard and soft tissue loss as a consequence of highvelocity close-range gunshots [8]. In all these varieties of injuries, the tissue damage is directly proportional to the kinetic energy transferred by the bullet, time taken for the energy transfer, and area over which the energy is transferred. Hence, the type and variant of injury have signifcant implications in management.

Apart from this conventional nomenclature, various other classifcations have been used for categorizing penetrating

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 59.5** (**a**, **b**, **c**) Blast injury caused by propagation of shock waves from the projectile. Soft tissue injury is minimal in such cases with severe comminution of the underlying skeleton

facial injuries; however, its application in clinical scenario is debatable. Similarly, many authors have developed an algorithm for the workup of ballistic wound based on the location of entry wound. Despite having limited application, no signifcant correlation has been found between site of entrance wound and therapeutic outcome of gunshot wounds [9].

A pragmatic approach to the management of such injuries involves:


### **59.3 Initial Evaluation, Triage, and Damage Control Surgery**

Initial management of gunshot wounds is based on the advanced trauma and life support protocols (also refer Chap. 48 of this book). Gibbons and Breeze [10] have elaborated the modifed military protocols pertaining specifcally to combat-related ballistic facial injuries. These include emergency management procedures that followed the CABC (catastrophic hemorrhage, airway, breathing, circulation) protocol proposed by Hodgetts et al. [11] which focused the need to control catastrophic bleeding as a priority over airway complications in a polytrauma patient. In a parallel manner, initial evaluation and damage control maxillofacial surgery should commence within the golden hour for effective patient management. Damage control surgery may be perceived as an immediate assessment of life-threatening injuries and addressing them promptly by means of early life-saving resuscitation and surgeries [12]. It is not regarded as a separate entity; it is seen as an essential, initial component in the management of any severely injured patient. In order to clear confusion clouding this highly debated area, a proposed set of damage control procedures that can be applied to ballistic maxillofacial injuries involving the maxillofacial region is given (Table 59.1).

Fortunately, the mortality rate directly attributable to maxillofacial frearms injuries is as low as 2–3% and predominantly due to a compromised airway [10]. Airway compromise is a serious consequence of all gunshot injuries to the face, and it can be due to a direct or an indirect injury to the airway. Injury to tissues and resultant edema in the vicinity of the air passages invariably handicaps the airway indirectly. Additionally, loss of muscle attachments and fractures of the anterior mandible signifcantly debilitates the airways. Manual repositioning of the fractured segments of mandible and base of tongue are the fundamental measures to be executed to prevent posterior airway collapse. While nasopharyngeal and oropharyngeal airways afford interim relief, endotracheal intubation is the established approach in emergency condition. This however presents a challenge on account of the edema, bleeding, and avulsed soft tissues that may possibly block the airway [13].

In the author's experience, a vast majority of maxillofacial gunshot wounds require surgical tracheostomy. The probability of concomitant intracranial injuries with low Glasgow Coma Scale (GCS) is also high in such patients [14]. Since most patients in this category require prolonged intubation and most gunshot wounds to the face require multi-phased surgical approach, the authors view surgical tracheostomy as having distinct advantage over other methods. Management of hemorrhage and its allied complications are well known in maxillofacial injuries as emphasized by previous writers on war surgery, yet it needs a descriptive analysis owing to the fatality it can cause. Hemorrhage is an inevitable consequence of all gunshot injuries to the face. Management of bleeding is an important aspect of damage control surgery, and adequate hemodynamic resuscitation is essential for the early physiological recovery of the victim [15].

Bleeding from high-energy ballistic injuries is practically impossible to control by external pressure tamponade due to the presence of bony structures and the inherently vulnerable condition of fragile anatomic structures like the eyes, brain, and airway seen in such injuries. In open injury scenario, hemorrhage can be easily managed by meticulous examination to recognize all the bleeding vessels followed by their ligation. Closed injuries necessitate balloon tamponade with Foley catheter (Fig. 59.5) to control bleeding. If bleeding is not controlled by the usual techniques, external carotid ligation or selective embolization method is used, which is by far the most predictable method to control bleeding from external carotid artery and its tributaries [13, 16].

#### **59.4 Diagnostic Imaging**

Once airway is secured and bleeding is controlled, attention should be directed toward radiological assessment of the injury. Depending on the severity of injury a plain X-ray, CT scan and CT angiography can be requested [15]. The extent of injury, degree of hard tissue fragmentation, location of metallic splinters, damage to C-spine, and any occult brain injuries can be easily delineated with the help of a CT scan. Similarly, involvement of great vessels, any concealed bleeding, and fow dynamics of vessels suitable for microvascular reconstruction can be studied using CT angiogram. Apart from the damage characteristics of the wound, another crucial factor which needs to be assessed during radiological examination is the status of C-spine.

Any injury of such magnitude enough to fracture the facial skeleton can invariably cause an occult C-spine injury. The incidence of C-spine injuries varies from 8 to 11% in all maxillofacial traumas [17]. Hence, potential cervical spine injury should be always considered unless proven otherwise clinically or radiologically. It is pertinent to immobilize the cervical spine to prevent further damage especially in unconscious patient (Fig. 59.6). However, substantial evidence is still lacking about the safety and effcacy of cervical collars

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 59.6** (**a**–**e**) Low-velocity close-range handgun injury—3D CT showing comminution of maxilla and NOE complex. The case was treated by ORIF mandible, maxilla, frontal bone, and cathopexy using iv cannula and wire. Three years post-surgery—adequate restoration of width and projection of midface

used in such injuries. Moreover, placement of rigid collars interferes during airway management, central line placement, and defnitive repair of facial injuries [13].

#### **59.5 Defnitive Management of Facial Gunshot Wounds**

The prime goal in the management of facial gunshot wounds is to rehabilitate the patient to pre-injury function and aesthetics. However, it is not always easy to get a fawless postoperative outcome with one particular treatment modality or a particular surgical technique. Hence, the treatment should be timed and tailored depending upon the type and severity of the injury, amount of tissue loss, general health status of the patient, surgeon's expertise, and availability of resources. Before initiating any treatment procedures, a thorough assessment of the wound by a multidisciplinary team is imperative as gunshot injury cases are seldom comparable. A comprehensive evaluation and discussion by a diverse panel gives the surgeon valuable perspectives which in turn has a positive impact on the fnal outcome.

#### **59.6 Debridement**

Modern high-velocity frearms transfer heavy cavitation energy inside tissues causing physiological and morphological alterations resulting in hemorrhage, thrombosis, and necrosis [18]. The tissue response toward the high-velocity projectile varies with the type of tissues and elastic deformation it can sustain. The dermis is viscoelastic, and injuries will result in abrasion, traumatic tattooing, and contusion particularly in close-range shots. Muscle tissues can withstand elastic deformation up to four times the size of the projectile, but at a cellular level, it may undergo signifcant necrosis, devitalization, and denaturation rendering the microenvironment favorable for bacterial multiplication [19]. The injuries to neurovascular bundles behave similar to muscles, thereby causing tearing, shearing, and rupture of blood vessels. At microscopic level, all the three layers of blood vessels get affected resulting in the formation of thrombus, infammation, and persistent spasm [20]. Cortical bone on the other hand is crystalline in consistency; therefore, penetrating injury causes fragmentation of bone with formation of multiple secondary projectiles. Conventional management of frearm injuries involves initial wound debridement, wound toilet, adequate soft tissue closure, and administration of antibiotics followed by delayed repair of deformities [4]. However, with the advent of vascular faps and new reconstruction methods, there has been a colossal shift in the management of such injuries to a more defnitive early single-stage repair [21].

The management commences with meticulous debridement of wounds to the point of active surgical bleeding. This strategy is particularly important in case of crushed and contaminated wounds wherein the active surgical bleeding encourages the formation of a healthy granulation tissue [18]. Furthermore, it also improves adequate microcirculation at wound margins, thereby promoting rapid healing and tissue resistance to infection. A serial debridement with judicious excision of the necrotic and non-contractile muscle tissues is done to achieve a wound with non-contaminated healthy margins [22].

After generous tissue excision, debridement should be assisted with soft scrubbing brushes and copious irrigation. Removal of deeply embedded splinters or metallic foreign bodies is controversial regarding any particular clinical benefts it offers [10]. The wound debridement should be prompt, and any delay (6–12 h) further complicates the wound management by progressive tissue necrosis. The development of progressive necrosis is a salient feature of gunshot wounds, and contrary to the popular belief, the tissue necrosis is not directly related to energy transfer but rather to the depth of tissues destroyed by the movement of the projectile. Animal studies have shown that beyond that critical time period, identifcation of necrotic margins will be diffcult and hence it complicates the debridement and surgical control of the wound [23].

There are two main areas of conficts pertaining to debridement in gunshot wounds. Many authors recommend immediate careful conservative soft tissue excision followed by secondary debridement of all tissues with questionable viability at a later stage [24, 25]. These researchers are of the view that it is practically impossible to distinguish between vital and non-vital tissues at initial intervention. On the contrary, a few other professionals believe in single-stage radical debridement on initial intervention [26].

Experimental evidences have shown that the extent of tissue necrosis after gunshot injury is 2 mm and 8 mm from the wound margins in skin and muscle tissues, respectively. In bony skeleton, it may extend up to 5 mm from the fracture line [27]. Thus, there is no convincing evidence to preserve fragmented bone of 1 cm or less during debridement even if it is attached to soft tissues. Similarly, a serial debridement of such wound is often required to deal with the evolving pattern of tissue necrosis over a period of 24–36 h. This allows for early identifcation of the demarcation zone between vital and non-vital tissues before reconstructive procedures are planned. The consensus of radical wound debridement at initial intervention aims to remove foreign bodies, necrotic tissues, and microbial contamination as early as possible. It also minimizes infammation, prevents infections, and helps in achieving favorable wound healing. Any late wound management in our opinion eventually increases the chances of infection, operating time, toxemia, and subsequent surgical intervention.

Concomitant injuries to salivary gland ducts and facial nerve are often encountered during initial debridement. The ducts and facial nerve are usually tagged with Prolene sutures for future repair. Most of the ductal injuries can be managed by cannulation and primary repair or by rerouting it into oral cavity. Non-salvageable glands should be removed without hesitation to prevent sialocele, salivary fstula, and complicated wound healing. Damage to facial nerve is mainly by thermal, avulsion, and stretch injury caused by the cavitation. Preferably the nerve should be repaired within 72 h for predictable results. Lacerated nerve is repaired primarily by coaptation or using nerve grafts harvested from greater auricular nerve. The nerve damage caused by cavitation may extend as far as 1.8 cm from the bullet track, and that should be considered during nerve grafting procedure [19]. Any facial nerve injury anterior to a line connecting mental foramen and lateral canthus is generally not repaired as spontaneous recovery is very likely in such cases.

#### **59.7 Infection and Role of Antibiotics**

Ballistic facial injuries are often compound and contaminated with high propensity for infection (class IV wounds). Contrary to the popular belief, all ballistic injuries are inherently contaminated, and the infection is primarily by the inoculation of microorganisms carried by the bullet and secondarily as a result of wound contamination in transit or in hospital environment. The actual incidence of infection rates remains elusive and ranges from 7 to 100% of all military facial injuries [28]. However, a general consensus is lacking in the timing, choice, and duration of antimicrobial therapy in combat injuries. Nonetheless the usage of broad-spectrum antibiotics for 10–14 days which provides cover against staphylococci, *Clostridium perfringens*, and *Acinetobacter baumannii* is commonly used [14, 29]. The critical level of bacteria required for initiating an infection reaches peak at 6 h of injury (105 bacteria/gm. of tissue), and studies have shown that early administration of antibiotics is paramount and any delay of greater than 6 h renders the treatment ineffective [30]. The accepted guidelines for combat-related injuries recommend administration of short-course, broadspectrum antibiotics preferably within 3 h of injury [31]. The use of antibiotics is an adjunct to scrupulous debridement for the prevention of infection and should always be considered in the initial management of ballistic injuries.

#### **59.8 Soft Tissue Reconstruction**

Gunshot wounds result in composite 3D defects with involvement of the skin, musculature, facial skeleton, and mucosa. The various reconstruction methods for wounds of these natures are prosthetic obturation, non-vascularized grafts with local tissue advancement, loco-regional faps, and free faps for large composite defects (Also refer Chaps. 86 and 88 of this book). Before initiating the reconstructive procedure, it should be kept in mind that the management of such wounds is often complicated by the ambiguity in prognosis caused by tissue loss, progressive necrosis, and infection. Therefore most critical facet while handling avulsive wounds lays in achieving and maintaining a favorable intraoral wound closure to minimize the chances of wound infection and wound dehiscence due to oral contamination [32]. It is always crucial to close the wound primarily because of the high propensity toward scaring and functional debility of wounds that heal secondarily. Most gunshot wounds can be closed primarily, and delayed wound closure in maxillofacial region is rarely necessary. However, two exceptions to this are (1) wounds which are not possible to debride completely at initial operation and (2) wounds with questionable vitality of tissues.

Sequencing of primary reconstruction of oro-facial region should follow an inside-out principle [33]. The injuries of the oropharynx are frst addressed by repairing the musculature and mucosa. This is followed by repair of oral mucosa, foor of the mouth, and the tongue. The reconstruction of lips, cheeks, and other extra-oral tissues is performed later after oral cavity has been reconstructed. Nonetheless if an acceptable intraoral closure is diffcult to achieve, a maxillomandibular fxation is done, and it is prudent to leave the wound to heal secondarily. While selecting a reconstructive option, it is important to consider a treatment plan which reduces the treatment time, patient morbidity, number of surgical intervention, and hospital stay [34]. The best possible function and aesthetics are achieved when debridement and reconstruction of hard and soft tissues are done at an early stage and the residual soft tissue deformities are addressed at a later stage with revision surgeries and local faps [2]. Extra-oral wounds that cannot be closed primarily due to excessive tissue loss are best managed by employing local, regional pedicled faps and microvascular faps.

Use of local faps and regional faps at the initial operation appears to be most favorable as far as aesthetics and function are concerned (Fig. 59.6a). Motamedi [2] advised early use of local faps in patients with gunshot wounds of the face. He reviewed 30 GSW patients and reported excellent cosmetic and functional outcomes. However, the disadvantages of local faps are that composite defects cannot be addressed and its availability, limited bulk, and pedicle length. Local tissue rearrangements and local faps with nonvascular grafts like iliac crest, rib, or cranium can be used for small defects. But large 3D defects and poorly vascularized surrounding tissues caused by cavitation often preclude the use of bone grafts with local tissue rearrangements unlike in tumor reconstruction.

Major avulsive and chop off injuries demand vascularized bone grafts with skin paddle for their reconstruction. Composite free tissue transfer is predictable, provides adequate bulk of well-vascularized tissue to fll the dead space, rehabilitates the buttresses, and reinstates the soft tissue envelope in a limited period of time [15]. The variables affecting the selection of fap depend on the type and amount of tissue loss, location, length of pedicle, donor site injury, and, certainly, surgeon's preference. The most commonly used faps for facial reconstruction are anterolateral thigh fap, radial forearm, and fbula with skin paddle [5]. It is obligatory to reconstruct both bone and soft tissues in composite defects, and without osseous support, soft tissue-only reconstruction tends to droop over time. After primary healing, the fap is contoured, subsequently unaesthetic skin paddle is excised, and local tissue can be re-advanced for better aesthetic outcomes. Similarly, if adequate vascularized tissue is not used for reconstruction, complications like scar contracture, bone graft resorption, fstula formation, and ultimately collapse of facial envelope will result.

It is clear that reconstruction of avulsive facial defects with free fap should be addressed as early as possible to prevent soft tissue contracture. Nonetheless, how much grace period is required before initiating a free fap reconstruction for optimizing the reconstructive outcomes is still not clear. High-energy cavitation in soft tissue may temporarily damage the local vasculature and hemodynamics at a distance from the margin of permanent wound. While planning a treatment based on microvascular reconstruction, it is imperative to have a conception of the zone of injury in its actual extent. Animal studies have shown that it is safe to place an anastomosis 3 cm away from the margin of wound track [35]. Furthermore, experimental evidences have shown superior results in integrity and patency of facial vessels anastomosed 3 days after injury than those repaired immediately after the injury [20]. If it is so, a composite free tissue transfer as a part of immediate reconstruction in avulsive ballistic injuries should be delayed till 3–4 days. This time period helps in adequate assessment of the extent of devitalized tissues, formulating a treatment plan based on available resources and optimizing the results by executing the treatment before the onset of soft tissue fbrosis and when the blood vessels are devoid of spasm.

Despite several arguments favoring immediate reconstruction for excellent aesthetic outcomes, it is to be noted that scar contracture is inevitable irrespective of the timing of treatment and reconstruction method adopted, although the frequency is more with delayed treatment [36]. Therefore, a review to determine the need for secondary corrective procedures should be conducted in consultation with the interdisciplinary team. Scar contracture is usually managed later by revision surgeries after the maturation of scar. The total number of revision surgeries required for a free fap is less as compared to local or regional faps. The outcomes of revision surgery depend on the type of fap used, complexity of the defect, and location of the defect with nasal, orbits, and lips requiring the highest number of aesthetic refnements [5]. Similarly other expected soft tissue complications like trismus, microsomia, and other functional disabilities can be addressed by fat grafting, coronoidectomy, commissuroplasty, and Botox injections [37]. Very often the reconstructive surgeries of aesthetically prominent regions of the face like nose and orbits are always suboptimal, and in such cases, prosthetic rehabilitation can be considered even though not physiological and patient compliance is less.

### **59.9 Fracture Stabilization and Hard Tissue Reconstruction**

Facial fractures resulting from gunshot wound are managed by applying principles governing other routine facial fractures based on AO-ASIF principles. The methodology for treatment varies and ranges from:


In patients without continuity defect, infection and minimal comminution open reduction and internal fxation (ORIF) is simultaneously done along with debridement at the initial stage.

Once initial stabilization is ensured, fxation is generally accomplished by miniplates or reconstruction plates. However, wounds with limited soft issue coverage require a different strategy as the granulation tissues may fail to cover thickness of plate resulting in subsequent plate exposure. Thus, if adequate soft tissue cover cannot be achieved, debridement, external pins, and maxillomandibular fxation (MMF) are the method of choice [33]. Until the introduction of surgical screws and plates, closed treatment was the preferred mode of treatment. The treatment ideology was directed to treat the whole wound as a "bag of bones" using external fxation or MMF in order to avoid periosteal stripping and devitalization of small fragments of bone. Although this therapeutic concept is advocated by several authors, who have reported signifcantly lesser rates of infection with this technique when compared with ORIF and plates, the value approach continues to be underestimated [38].

The advantages of external fxation are manifold. It helps to prevent bone devascularization, allows for bone regeneration, and also provides adequate support to the comminuted fracture fragments. Additionally, it also enhances the osteogenic potential of the injury site by helping in spontaneous bone regeneration. This phenomenon is more commonly seen in young patients due to hypoxia and acidosis-induced activation of local bone morphogenic proteins (BMPs). The high-velocity trauma causes extensive damage to adjacent muscles and periosteum. This damage along with the effects of local infammation, hypoxia, and increased carbon dioxide concentration activates BMPs resulting in spontaneous bone formation. The concept and knowledge regarding facial buttress and its implication in trauma management have added a new dimension in the functional and aesthetic reconstruction of the face. As a result, internal fxation using locking plates has greatly replaced external fxators over a period of time. It is currently the most widely used technique in management of GSWs with bone loss and is used if the fracture fragments are large enough to accept screws.

Additionally, bone defects if any should be grafted with harvested iliac crest, ribs, or cranium depending upon the size of the defect (Fig. 59.7). However, the infection rates associated with internal fxation are comparatively higher as quoted by many authors. The increased rates of infection associated with ORIF are due to loosening of hardware and subsequent micromotion at the fracture site and possibly by contamination by oro-nasal fora. Motammedi [2] reported that it is almost impossible to achieve occlusion without arch bars and MMF in majority of gunshot fractures. Presently ORIF along with arch bars continue to be the mainstay in the management such patients. With the advent of new techniques of reconstruction supplemented by innovative plates and screws, vascular grafts and antibiotics have heralded a paradigm shift in the treatment philosophy. Current principles clearly favor early defnitive reconstruction of hard tissues with ORIF using rigid fxation supplemented by MMF and bone grafts whenever required (Fig. 59.8).

#### **59.10 Timing of Defnitive Reconstruction**

An area of ongoing debate and controversy in the management of gunshot wounds of the face is regarding the timing of defnitive reconstruction [6, 39]. Although previous teachings and practices were in favor of delayed reconstruction, the more recent studies demonstrate predictable functional and aesthetic outcomes with immediate defnitive reconstruction [40–42]. Scientifc studies suggest carrying out defnitive reconstruction within a time frame of 48 h would yield the best possible outcome [2].

Advocates of delayed reconstruction believe that the delay in treatment reduces the probability of infection, necrosis, and postoperative wound complications exponentially. Additionally delay in treatment reduces the chances of mortality and morbidity due to infection and progressive tissue necrosis [43, 44]. Any increase in postoperative temperature, raised leukocyte counts, and other local signs of infection may invariably cause a failure in fap due to risk of venous thrombosis. It has also been suggested that the decreased infammation and edema aid surgeons to have a better assessment of the extent of injury, thereby helping in precise and desired treatment planning which in turn could lead to a better outcome. Therefore in their opinion, it is prudent to wait before applying any principles of primary reconstruction until a healthy tissue bed is achieved. On the other hand, the disadvantages of delayed treatment are increased treatment time, prolonged hospital stay, increased cost of treatment, and patient distress caused by psychosocial impact of disfgurement associated with gunshot injury (Tables 59.2 and 59.3).

Advocates of early primary treatment claim superior functional and aesthetic outcomes, early restoration of facial form, and limited hospital stay with early return to normal

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 59.7** (**a**–**d**) High-velocity close-range assault rife injury with comminution of mandible and soft tissue loss. Managed initially by non-vascularized graft and later by free fbula osteocutaneous fap

reconstruction. External fxator for stabilizing fbula in place. Follow-up after complete treatment

function [4, 14, 45]. These benefts are predominantly due to the elimination of soft tissue contracture by proper anatomic coverage of soft tissue at an early stage [21]. Vasconez et al. [42] compared the infection rates of gunshot wounds that have been managed by early and late reconstruction in a series of 33 cases. In their observation, they could not found any signifcant difference in infection rates between the two groups. However, the delayed group showed an apparent increase in the incidence of scar contracture with signifcant functional and aesthetic complications. Similarly, several other studies have also reported excellent clinical outcomes when immediate reconstruction is carried out [46].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 59.8** (**a**–**d**) High-velocity assault rife injury to the face with loss of hemimaxilla and mandible along with partial loss of upper lip was done. Reconstruction of the upper lip by hair-bearing submental island fap. Mandible reconstruction is performed by vascularized fbula

Defnitive management of most maxillofacial injuries is not a surgical emergency, and treatment is often delayed in polytrauma patients. A standard consensus for delaying treatment and adopting a staged approach in such cases is due to the inability of a critically injured patient to undergo surgical intervention. However, as soon the patient is deemed to be medically stable, operative intervention targeted toward managing the facial injuries should be initiated. It is imperative to address the bony and soft tissue injuries soon after the resolution of edema and before the initiation of fbrosis of

**Table 59.2** Advantages and disadvantages of immediate reconstruction




soft tissues and malunion of fractures. This grace period will allow the surgeon to have an accurate and swift identifcation of subtle deformities for a major single-stage intervention rather than repeated assault to soft tissues causing fbrosis and decreased vascularity.

The essential difference in the management of routine maxillofacial injury and gunshot wounds of the face is the requirement of a multidisciplinary team for the management of gunshot wounds. Therefore, a short-term delay or temporizing such wounds allows time to procure diagnostic images and study models and lastly for a discussion on inputs from the medical and surgical team. In general, the formulation of treatment plan should be based on the general health status of the patient, availability of resources, surgeon's expertise, and patient's will.

In a vast majority of cases despite the primary management approach, a signifcant number of gunshot injuries are plagued with residual functional and aesthetic problems. Hence, a good postoperative outcome is multifactorial and is the refection of all the above factors and not just the early defnitive repair. However, a large number of maxillofacial gunshot wounds can be treated defnitively at the time of iniThe general physical status of the patient, timing of surgery, extent of composite tissue damage, good surgical techniques, use of appropriate hardwares, antibiotics, and proper rehabilitation are the factors which determine the fnal outcome and aesthetic result in a penetrating facial injury.

tial intervention if the general condition of the patient and expertise of surgeon permit and the benefts of such an approach are manifold.

#### **59.11 Recent Advances**

Several recent advances have signifcantly improved the morbidity and survival rates in complex maxillofacial gunshot injuries. More importantly they serve as a support system to the surgeons, enabling them to appreciate and attend to the fner aspects of complex composite injuries. This in turn paves the way to achieve far more superior reconstructive outcomes. Contemporary techniques employ virtual surgical planning, patient-specifc stereolithographic models, as well as intraoperative navigation and imaging (Refer Chap. 41 of this book). These modern-day techniques help elevate the surgical experience to one that is more precise, faster, and minimally invasive.

Composite tissue alloplastic transplantation or face transplantation is yet another recent innovation in this feld. This treatment is rendered for patients with massive loss of hard and soft tissues of the face or in cases where the fnal outcome is suboptimal even after multiple surgeries. However, it is not in the mainstay treatment of gunshot wound of the face because of the diffculties in fnding an appropriate donor, lack of expertise, requirement of long-term immunosuppressants, absence of long-term follow-up, and associated ethical issues.

#### **59.12 Conclusion**

In conclusion, the management strategies of patients with facial gunshot wounds are almost as diverse as the case presentation itself. This chapter ascertains that the blueprint for actions in the management of facial gunshot injuries has undergone signifcant change over the last decade. A new understanding of the inherent osteogenic potential of the human body in the face of contemporary warfare coupled with the availability of state-of-the-art equipments and facilities favors a brisk early approach. Thus, present guidelines essentially direct surgeons to do as much as possible for the gunshot patient with regard to hard and soft tissue reconstruction of the face and jaws within 48 hours. The treatment in such cases is more comprehensive with intent to simultaneously debride and reconstruct.

#### **References**


graphics, pathophysiology, and management. J Oral Maxillofac Surg. 2003;61:932–42.


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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**60**

## **Panfacial Fractures**

Kiran S. Gadre, Balasubramanya Kumar, and Divya P. Gadre

#### **60.1 Introduction**

Most facial fractures occur in combinations involving various subunits of craniomaxillofacial (CMF) skeleton [1] (Fig. 60.1). Severity of these injuries is determined by multiple factors such as its aetiology, causative factor, force of impact, pre-existing patient factors, etc. High velocity road traffc accidents RTA / assaults are the most common cause of panfacial fractures. With a large number of different patterns these fractures project, it is challenging to have a proper defnition of "panfacial fractures". It is well-known that fractures involving multiple bones of the face is known as panfacial fracture. It could be described as "fractures involving upper third, middle third, and lower third of face with at least one condyle, palate and fronto-naso-orbito-ethmoidal complex (FNOE) fracture" (Fig. 60.2). When there is skull base or co-existing neurosurgical involvement, it is termed as craniofacial fracture. Managing these cases is extremely complicated as each of them present with unique pattern of hard and soft tissue injury. This demands a team approach as these injuries are commonly seen in polytrauma with multisystem involvement. Airway compromise, severe haemorrhage, large open wounds, severe ocular/orbital injuries and coincidental surgical procedure being performed are the only indications for immediate defnitive surgical intervention. Restoration of form and function at the earliest opportunity should be the goal of maxillofacial surgeons.

B. Kumar

Department of Maxillofacial Surgery, St. Marthas's Hospital, Bangalore, Karnataka, India

Bhagwan Mahaveer Jain Hospital, Vikram Hospital, Bangalore, Karnataka, India

D. P. Gadre Gadre Clinic, Pune, Maharashtra, India

#### **60.2 Epidemiology**

Global status report on road safety (2015) indicates that more than 1.25 million deaths, and 15–20 million injuries occur in road traffc accidents (RTA) costing most countries 3% of their GDP [2]. Countries with low and middle income having 54% of vehicles account for 90% of RTA-related fatalities, mostly of subjects aged between 15 and 44 years. RTA is the main cause of mortality in three quarters of males in 15–29 years age group. The true economic and public health impact is not estimated in most developing countries due to lack of infrastructure and resources [3].

Panfacial fractures are caused by high-energy impact, usually generated as a result of RTA or frearm injury directed at CMF skeleton, and it also has a contrecoup component causing associated cranio-cerebral or cervico-spinal injuries with a low Glasgow coma scale. These injuries can also cause associated injuries like rib fracture/pulmonary contusion, pneumothorax or intra-abdominal injuries, limb and pelvic injuries and require immediate treatment.

#### **60.3 Management Philosophy**

Restoration of form and function is the ultimate goal in treating panfacial injuries. Proximity to important structures like the brain, eyes, auditory apparatus and spine necessitates a holistic approach to their management involving neurosurgeons, ophthalmic surgeons, ENT surgeons, maxillofacial surgeons and anaesthetists.

It is challenging to follow an established pattern of repair as each case is unique and requires skill and expertise of the surgeon to restore the pre-traumatic anatomy of facial function with aesthetics. Despite all the aggressive treatment, many patients with panfacial trauma may need further correction of residual deformities.

© The Association of Oral and Maxillofacial Surgeons of India 2021 1283

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_60

K. S. Gadre (\*)

Gadre Clinic, Pune, Maharashtra, India

Department of Oral and Maxillofacial Surgery, Bharati Vidyapeeth Dental College and Hospital, Pune, Maharashtra, India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 60.1** Schematic diagram depicting subunits of facial skeleton

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 60.2** 3D CT scan image showing panfacial fracture involving the upper, middle and lower third of face

#### **60.3.1 History of Management**

The management of panfacial fractures has changed during past few decades, particularly after the 1990s, when indigenous plating systems were more freely available.


A better understanding of anatomy, pathophysiology, anaesthesia, sterilization and asepsis with advances in intubation techniques (transmylohyoid/submental, bronchoscopic) and instrumentation (fberoptic and endoscopic) and instrumentation has infuenced the management of these complex injuries signifcantly (Chap. 7 deals with Anesthesia and intubation techniques in maxillofacial surgery). Use of engineering technology like three-dimensional planning, stereolithographic models, endoscopic and navigation techniques has simplifed the accurate treatment of these fractures, avoiding injury to other vital structures and saving intra-operative time (Fig. 60.6a–d).

#### **60.3.2 Indications**

Panfacial fractures can be disfguring and cause signifcant functional problems like diffculty in mastication, deglutition, speech, olfaction and abnormalities of vision. Early fxation of displaced fractures causing the above problems is warranted. Undisplaced/minimally displaced fractures can be left for a few days, buying some time to manage other grievous injuries. It is necessary to understand that sense of urgency for treatment should exist in treating any panfacial fracture (within 15 days, provided other parameters are permitting).

#### **60.3.3 Contraindications**

There are no absolute contraindications but relative contraindications which cause delay of treatment, are presented below.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 60.3** (**a**) POP head cap used in traditional days. (**b**) Interosseous wiring (yellow arrow) with internal suspension (blue arrow)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 60.4** Plating with internal suspension (blue arrows)


Reduction of facial oedema further unmasks the underlying fractures and facial deformity. This gives an opportunity to review the imaging and prepare necessary splints (see Sect. 55.7.1) (Fig. 60.7a, b). These are very essential to establish width, height and anteroposterior projection of the facial skeleton, particularly where large dentoalveolar segments have been lost along with the presence of bilateral condylar fracture.

3. When a combination of avulsive injury (Chap. 49 deals with management of Soft tissue injuries in maxillofacial region) and panfacial fractures is present, golden hour reconstruction should be utilised, if circumstances and conditions permit. This is the best time as patient is in optimal physiologic and physical condition.

#### **60.3.4 Clinical Findings**

The clinical fndings in panfacial trauma are a combination of signs and symptoms as seen in various subunits of facial fractures with increased severity (readers are advised to refer the respective chapters on maxillofacial trauma for signs and symptoms and management of fractures of mandible in Chap. 52, Fractures of the Condyle in Chaps. 53 and 54, fractures of maxilla in Chap. 55, fractures of the zygomatic complex in Chap. 56, fractures of the orbit in Chap. 57, fractures of the frontal naso orbit ethmoid region in Chap. 58 and Gun shot injuries in Chap. 59).

Facial oedema makes examination and standard radiography diffcult. Bilateral raccoon's eyes and elongated dishshaped face, with presence of orbital dystopia, traumatic telecanthus and deranged occlusion, are commonly seen. There may be elements of severe dento-alveolar trauma and soft tissue injury which may vary from minor contused or lacerated wounds (CLW) to avulsive injuries.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 60.5** (**a**, **b**) Plating of panfacial fractures as seen on (**a**) posterioranterior Caldwell view of mandible and (**b**) posterior-anterior Water sinus view radiographs

Presence of cervical, cranial and other concomitant injuries must be assumed till proved contrary. Similarly absence of teeth, dentures in mouth must be assumed to have been swallowed or aspirated until proven otherwise.

#### **60.4 Workup**

The pre operative planning consists of two parts: (a) imaging and (b) diagnostic procedures.

#### **Imaging:**

Standard radiographs like posterior-anterior (PA) view, Caldwell view of mandible, Water's view, submento-vertex view, cervical spine radiographs have been used as a baseline in any emergency and are easily available in most settings. Computed tomography (CT) images with 3D reconstruction is now considered the gold standard in complex facial trauma patients as it provides a 1:1 information of the fracture pattern. 3D planning softwares help the surgeon in meticulously planning cases preoperatively.

CT imaging is commonly done for assessment of brain and spinal cord in a head injury patient to exclude intracranial haemorrhage and other grievous injuries. Facial skeleton should be included in the same scan in suspected facial bone fractures.

Coronal and sagittal sections of the CT scan could be obscured by the endotracheal tube in intubated patients. Axial and three-dimensional images with computergenerated models can be used for assessing most facial fractures in these cases (Fig. 60.8a, b).

#### **Diagnostic Procedures:**

Occlusion of teeth is the key to reduction and fxation of facial bone fractures. Mock surgery using dental models help in repositioning the teeth-bearing segments including dentoalveolar and palatal fractures and aid in fabricating acrylic stents and splints (Fig. 60.7). They are essential in cases where there is gross occlusal disturbance, splaying of basal bone or multiple fractures of dento-alveolar segment.

#### **60.5 Emergency Treatment**

Complex maxillofacial trauma are mostly high impact injuries and are usually a part of life-threatening injuries involving other organ systems like central nervous system, chest, abdomen, pelvis or limbs. It is important that these injuries be assessed and managed prior to or simultaneously as facial injuries.

Current standards of care for trauma patients, whether polytrauma or those involving the CMF skeleton, mandate that one must follow the Advanced Trauma Life Support (ATLS) protocol relating to airway, breathing, circulation, disability and exposure in that sequence. Airway and circulation should have the highest priority (Table 60.1). This is followed by an assessment of the patient's neurological, visual and cervical spine status. The details of primary and emergency management of polytrauma patients are dealt in Chap. 48 of this book.

Patients with polytrauma/panfacial fractures can require immediate or late treatment depending on the mechanism and kind of injury. Occasionally, immediate treatment can be the defnitive procedure. An immediate intervention may be done merely for initial stabilization of the patient; procedures demanding a more detailed assessment and planning will need to be postponed. Immediate initial treatment in patients with maxillofacial injuries is indicated in following situations.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 60.6** (**a**–**d**) Showing few of advances from various specialities of medicine and engineering contributing to advances in management of panfacial fractures. ((**a**) Bronchoscopic intubation, (**b**) transmylohyoid intubation, (**c**) fbreoptic instruments, surgical saw, (**d**) stereolithographic model)

#### **60.5.1 Airway Compromise**

Obstructed airway is an important sequel of panfacial fractures and is managed either by temporarily reducing and stabilizing the fractured facial bones and attached soft tissues or performing a surgical tracheostomy. Patients with C-spine injury can be challenging to intubate due to inability to fex or extend the neck, as is establishment of a surgical airway like tracheostomy.

#### **60.5.2 Severe Haemorrhage**

Reduction and stabilization of fractured segments not only helps to correct airway but also controls severe bleeding. Haemorrhage not amenable to the above procedure may necessitate packing, identifcation of causative bleeder and its cauterisation or ligation. Occasional ECA control may be required, if multiple ipsilateral bleeding areas or unidentifed areas of bleeding are seen. In centres where the facility is available, uncontrollable bleeding from facial region (especially after comminuted midface fractures) is controlled with selective embolisation by a interventional radiologist.

#### **60.5.3 Large Open Wounds**

These are commonly used to fx the fractures beneath them. In such situations initial washout and primary approximation should be done when possible for haemostasis and maintaining continuity of vascular supply, especially in cartilaginous areas like the ears and nose. This closure is basically a primary tacking of the wound margins. Layered closure is better done under controlled conditions along with fxation of the fractures under anesthesia [1].

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 60.8** (**a**, **b)** Depicting importance of high-resolution CT scan in an avulsive injury to assess nature and extent of injury and achieve predictable outcomes

#### **60.5.4 Surgery for Associated Life-Threatening Injuries**

Occasionally, patients with polytrauma undergo immediate surgery to treat other grievous injuries. This provides an opportunity to perform initial debridement, assessment and stabilisation and make dental impressions for fabrication of a customised splint. Considering the planning and surgical time required for comprehensive management of panfacial fractures, it is usually not advisable or possible to perform fxation during emergency management of other more severe injuries (neurological/abdomen/long bones/chest).

It is always wise to initiate assessment of a head injury or polytrauma patient using the ATLS (Advanced Trauma Life Support) protocol. A detailed record of all maxillofacial injuries should be made. Diagrams and representations of fracture patterns and soft tissue injuries make it easy for the understanding and execution of treatment. It is important to document the whereabouts, mechanism and time of injury accurately, to minimise medico-legal problems at a later date. Photographs are a good medium of educating the patients with their attenders and recording the preoperative soft tissue injuries.


**Table 60.1** Immediate management of a polytrauma patient

#### **60.5.5 Defnitive Treatment**

Paul Manson's quote "you never get a second chance" has to be kept in mind, i.e. the time frame [5] regarded appropriate for primary fracture treatment is limited to 2 weeks. After 2 weeks, the treatment is regarded as delayed and may necessitate secondary post-traumatic reconstruction (see Chap. 60 on residual deformities of the maxillofacial region).

#### **60.6 Preoperative Documentation and Planning**

Preoperative treatment planning is essential for successful outcomes. One must gather enough information and documentation to help in formulating an accurate treatment plan.

This can include:


A proper evaluation by ophthalmologist, ENT surgeon and Neuro Surgeon is mandatory before proceeding with panfacial fracture fxation, and these allied specialities may be part of the surgical team for comprehensive management of the panfacial injuries.

Large bony defects with loss of soft tissue are best treated immediately or secondarily with local, pedicled non1289

vascularised or vascularised-free faps provided the wound is clean and non-infected. Tissue shrinkage should be avoided as much as possible in these special situations by using techniques of maxillomandibular fxation (MMF) and internal or external fxation devices or splints. Immediate reconstruction can be planned in clean wounds. Need for transmylohyoid/submental endotracheal intubation as an alternative to tracheostomy should be explored in discussion with the anaesthesia team [6], especially in panfacial trauma involving nasal bones and skull base fractures needing fxation of maxilla and mandible.

#### **60.7 Intra-operative Details**

The essential in treating panfacial fractures is obtaining adequate fxation at key buttresses (Fig. 60.9a, b, Fig 55.2). Its description was frst given by Cryer in 1916 [7]. This helps in creating the outer framework for fxation of other fractures.

#### **60.7.1 Buttresses of the Facial Skeleton**

These are the regions of thick bones which neutralise the forces applied onto them.

Outcome of maxillofacial reconstruction in terms of restoration of facial height, width and projection in addition to restoring the occlusion depends on proper reduction and fxation of these buttresses [8, 9] (Table 60.2).

They are important to:


#### **60.7.2 Key Contributors to Facial Architecture**


markings of facial buttresses (Correlate with Table 60.2) (Also see Fig. 55.2)

©Association of Oral and Maxillofacial Surgeons of India



#### **60.7.3 Various Approaches to Facial Skeleton**

Approaches to individual facial bones are discussed in the respective sections of the book. They are enumerated here for quick reference and revision.

Facial lacerations overlying fractures should be used for access when possible (Fig. 60.10a−d). In situations without any such lacerations, appropriate incisions for respective fractures should be used as described in other sections of this book.

Subciliary or transconjunctival incisions are commonly used to provide access to infraorbital rim and orbital foor; lateral brow or upper blepharoplasty incisions provide access to frontozygomatic suture and lateral wall of orbit; intraoral vestibular incision provides access to maxilla and zygomatic buttress; and coronal incision provides access to frontal, fronto-naso-ethmoid complex, zygomatic arches and roof of orbit.

Mandible symphysis, parasymphysis, can be approached through intraoral vestibular or crevicular incisions. Mandibular angle is approached intraorally through an extended 3rd molar incision alone or in combination with a transbuccal approach using a trochar and cannula. The condylar head will need to be approached through preauricular or bicoronal incision, whereas the mandibular subcondyle and ramus can be approached through retromandibular or peri-angular incision. Endoscopic approach to the mandibular condyle is been popularised in a few units (see Chap. 54 for details on endoscopic approach to condylar fractures).

Sequencing of fxation in panfacial fractures is a challenging task. The sequencing will alter slightly depending on clinical and radiological evaluation.

#### **60.8 Sequencing Options**

There are two options for sequencing:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 60.10** (**a**–**d**) Use of existing laceration to achieve optimal results

important,and is surely done prior to rigid fxation of Leforte I and mandibular fractures.

Although author's preference is "bottom to top" approach, as establishing functional occlusion is of prime importance, a combination of both the approaches might be necessary in many situations (Fig. 60.11).

#### **60.8.1 Bottom to Top Approach**

1. When using this approach one is committed to using the mandible as guide for establishing the height, width and projection of face. Hence after occlusion is established, the mandible is rigidly fxed from one condyle to the other. This makes it necessary to plate minimum one condyle in case bilateral condylar fracture. It is necessary to ensure proper seating of mandibular condyle into the glenoid fossa.


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 60.11** Use of combination techniques to achieve stable fxation schematic diagram

4. The next step is to begin the reduction and fxation of the remainder of the midface starting from the calvarium and working in a caudal direction similar to "top to down" sequencing.

### **60.8.2 Top to Bottom Approach**


Fixing the zygomatic arch increases the accuracy of multidimensional reconstruction (frontozygomatic suture, infraorbital rim, zygomaticomaxillary buttress, zygomatic arch) of fractured and comminuted zygoma [13, 14].


The midface, because of weak bone structure and comminuted fracture pattern, must be considered a dependent and less stable structure.


Tulio etal advocated fxation of condylar fractures as the frst step in fxation of pan facial fractures. In their study there was no evidence of dental or skeletal alterations and measurement of the mandibular ramus and radiographic examination show that posterior facial height as well as projection and width of the inferior lower third of the face, was restored. The correct timing of surgical intervention and the use of rigid fxation allows the restoration of the morphological and functional nature of the face after pan facial fractures [15].

10. The occlusion should be rechecked, and rigid or elastic maxillomandibular fxation may be considered as necessary for 4–6 weeks. The occlusal splints may be fxed using wires for the period of MMF as a guide to maintaining the occlusion.

The sequencing for pan-facial fractures depends more on the clinical situation, than on predefned algorithms as the patterns of clinical presentation may be diverse. However, the general consensus in current literature emphasizes that the the dental units are given priority for providing guidance. The dental arches are frst stabilised to form a **Table 60.3** Bottom-up inside-out and top-down outside-in, comparison of sequencing


cohesive unit, followed by the mandible in its horizontal and vertical dimensions (10, 19) (also see Manson 2012 in additional reading). The mid face is then managed using a top-down or a bottom-up method depending on the presence or absence of bony defects in the calvarium.

#### **60.8.3 Essentials in Either Approach**


The sequence of the above approaches are compared in Table 60.3.

Author follows the *"Wire before you plate"* principle.

It is author's preference to use initial wire osteosynthesis stainless steel (SS) for better alignment and anatomical reduction at multiple sites before plating. This technique also does away with the requirement of holding fragments together, and with less of instrumentation in the surgical

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 60.12** Three concentric circles used as a guide to the reduction of panfacial fractures (Adapted from: H.C Killey. Fractures of Middlethird of facial Skeleton, Issue 3 of Dental Practitioners Handbook, No.3)

feld, there is an obvious ease of plating more precisely. Wire osteosynthesis should be removed following fxation of the fractures to avoid or prevent reaction between dissimilar metals, namely, SS (stainless steel) and Ti (titanium).

There are other sequencing methodologies and philosophies as suggested by other authors.

Manson et al. put forward a highly conceptualised treatment protocol where face is divided into groups, units and sections, and each section is assembled in three dimensions. Soft tissue is considered the "fourth dimension" of facial reconstruction. They advised bone reconstruction to be completed as early as possible to minimise soft tissue shrinkage, stiffness and scarring of soft tissues in non-anatomic position [1, 16].

Killey and Kay demonstrated the fxation of panfacial fractures frst in the outer ring followed by the middle ring and lastly the nasal complex in the inner ring (Fig. 60.12).

Inside-out sequence was also found to show good results by Kim et al. [17].

The occlusion frst approach, with initial reduction of larger segments, enables effective reconstruction of multiple segments. Smaller segments can then be oriented to fxation of these fractures [18].

Role of bone grafts in very comminuted fractures or missing bone demands immediate bone grafting to produce a stable outcome. Commonly used areas of bone and cartilage grafts are rib, calvarium, iliac crest and conchal cartilage [19]. Recipient site requirements determine the ideal donor site for replacing bone. Revascularisation potential and mechanical needs of the donor site are two factors known to infuence this [20].

#### **60.9 Paediatric Panfacial Fractures**

They are rare and different as the cranium to face ratio is 8:1, and also differential growth in eyes, brain and face makes a difference in pattern and incidence of fractures. Children should not be treated as small adults as its not only important to restore them to normal form and function, but the growth potential also should be taken into consideration. One must remember that both injury and treatment can lead to growth disturbances, and hence many times conservative management is preferred. Splints are the mainstay in treatment of paediatric fractures (Figs. 52.50 and 52.51). Panfacial fractures are preferably treated with resorbable plates to prevent growth disturbances and damage to tooth buds. This also avoids second surgery for plate removal. Furher, it must be kept in mind that minor occlusal discrepancies are self-corrective during transitional dentition phase or can be treated easily with orthodontics at later date. Major emphasis should be on preventing deformities in central midface. Paediatric patients have to be followed up till growth has completed. In developing countries wire/resorbable suture osteosynthesis can be utilised for economic reasons and availability [21].

#### **60.10 Complications**

Complications associated with panfacial injuries include those associated with individual fractures of frontal sinus, nasal and fronto-naso-ethmoid, zygomatic, maxillary and mandibular fractures.


#### **60.11 Tips and Tricks**


securing the MMF. Debride contaminated wounds thoroughly before closure.


#### **60.12 Case Scenario**

#### **Case 1:**

(Figs. 60.13a–d, 60.14a–f, and 60.15a–c) Shows Management of a Case of Pan Facial Fracture

Figure 60.13 shows the pre operative CT scans, Fig. 60.14 show the various surgical approaches used for internal fxation and Fig. 60.14 shows the post operative radiographs showing the fxation.

**Fig. 60.13** (**a**–**d**) Panfacial trauma preoperative CT scan. (**a**) Right condylar fracture. (**b**) Naso-ethmoid complex fracture, left zygomatic buttress and infraorbital rim fracture. (**c**) Mandibular symphysis fracture. (**d**) Left condylar fracture

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 60.14** (**a**–**f**) Panfacial trauma intra-operative images of case shown in Fig. 60.14. (**a**) Left retromandibular approach (**b**) Right retromandibular approach. (**c**) Right condyle plating. (**d**) Symphysis exposure. (**e**) Right frontozygomatic fracture. (**f**) Naso-ethmoid fracture exposure

©Association of Oral and Maxillofacial Surgeons of India

operative photographs. (**a**) Frontal view showing asymmetrical face, alar bases, lip and deepened supra tarsal fold (yellow arrow). (**b**) Lateral view showing upturned lip, increased vertical dimension, scar on left body of mandible. (**c**) Malocclusion with anterior open bite. (**d**) Pre-operative P.A. Waters view showing inadequate fxation of midfacial fractures and foreign body within right orbit (Red arrow)

#### **Case 2** (Figs. 60.16a–d, 60.17a–e, and 60.18a–d)

#### **Back ground:**

This case was treated in 1997 by the frst author, when CT scan was a novelty rather than necessity. Plating system used was stainless steel.

A 43 years male with no comorbidities was referred by dental surgeon for correction of malocclusion and asymmetrical face. Patient had a history of RTA with panfacial fractures, and head injury, cerebral oedema 3 months prior. He was treated conservatively for head injury and had no residual neurological defcit. He was treated by other specialist for panfacial fractures by ORIF and then referred to dentist for prosthetic correction of occlusion. Patient insisted upon simultaneous correction of occlusion and asymmetric face.

#### **Patient reported with complaints of:**

Inability to masticate, changed pattern of upper and lower teeth meeting , crooked nose with asymmetric nasal bases, sunken left eyeball, diplopia on superior gaze, and changed facial appearance compared to preinjury status.

#### **Clinical Findings** (Fig. 60.16a–d)


**Fig. 60.17** (**a**–**d**) Intra-operative representative photos. (**a**) Fixation at FZ suture. (**b**) Fixation at inferior orbital rim. (**c**) Entrapment of inferior rectus, left orbital foor (yellow arrow). (**d**) Fixation of LeFort I fracture. (**e**) Fixation of bone graft to augment nasal bridge

#### **Diagnosis:**


#### **Radiological Findings**

Inadequate fxation seen at bilateral Fronto Zygomatic (FZ) suture, LeFort I,II,III level, and FNOE complex. A Foreign body (broken drill) was seen in Right orbit near FZ suture ( red arrow). Mandible was fxed adequately both radiologically and clinically.

#### **Plan of action/surgical approach** (Fig. 60.17a–e)


**Fig. 60.18** (**a**–**d**) Ten years Post-operative photographs. (**a**) Frontal view showing restored symmetry. (**b**) Lateral view showing correct lip positioning, corrected vertical dimension, scar on left body of mandible.

(**c**) Corrected occlusion. (**d**) Post-operative P.A. Waters view (Full face) showing adequate fxation of midfacial fractures at all the struts

10. Avoid MMF. Post-op X-ray (Fig. 60.18d) shows plating with wires, they were not removed as hardware used then was stainless steel so there was no issue of Eddy's current due to dissimilar metals.

#### **60.13 Conclusion**

The increasing number of RTA and related CMF injuries suggests the need for immediate attention from the concerned authorities, to enforce strict laws like mandatory use of seat belts and total head and face guard (that suit climatic conditions) rather than the conventional helmets. Restricting the use of mobile phones and head phones while driving may lead to decrease in the incidence of RTA. If RTA is considered an epidemic of modern times, then prevention is its vaccine. Increasing public awareness towards voluntary use of safety measures for their own safety rather than merely obeying the rules can reduce most of the cranio-maxillofacial injuries.

Panfacial trauma can appear complex and challenging to treat but is actually the conglomeration of treating individual fractures that are a common place in maxillofacial injuries (it would be wise to "simplify" the fracture in the minds' eye view and formulating a treatment plan). Adhering to a treatment protocol and treating each fracture as a unit, with adequate fxation, enable the surgeon to obtain good results. Development of a sequential and methodical treatment plan prior to surgery and adherence to the basic principles of maxillofacial trauma is vital in treatment of these patients.

#### **References**


cadavers based on clinical practice. Plast Reconstr Surg. 2002;110:14630–71.


#### **Additional Reading**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Residual Deformities of the Maxillofacial Region**

Samson Jimson

#### **61.1 Introduction**

A maxillofacial surgeon plays a vital role in not only restoring the structural form of the maxillofacial unit but also aims to restore the pre-traumatic functional status of the patient. Diagnosis, clinical evaluation with enhanced treatment planning and restoration of aesthetics and function is the key for any maxillofacial surgery. However, it is not always possible to achieve the most appropriate results in all cases. It is not uncommon to see failure or mediocre outcomes following maxillofacial trauma surgery. The outcome of the primary treatment may depend on factors such as the extent of the injury/defect, delay in diagnosis/management, improper treatment plan, lack of utilizing modern diagnostic/treatment planning utilities, poor execution of treatment plan and inexperience of the surgeon. These may lead to not expecting the eventful deformities and not coordinating with other specialists to yield the most standard and deserving treatment for the patient with restoration of both form and function [1–3].

Residual deformities are seen following primary treatment of trauma due to one more reason mentioned earlier. Correction of such residual deformities may be challenging to the surgeon but very often a life-changing experience for patients. It is the experience of the surgeon that helps to recognise the challenges ahead in restoring the form and function. Residual deformities are often evaluated by the extent of deformities following primary management. Apart from reasons that may pertain to the experience of the operating surgeon, pathobiology of the healing zone may also contribute to the residual deformities. A variety of such reasons contributes to both soft tissue and hard tissue defects in the maxillofacial unit. This chapter aims to discuss in detail the clinical evaluation, diagnosis, protocols,

S. Jimson (\*)

management and post-operative care of hard tissue deformities in oral and maxillofacial surgery with emphasis on current trends and future propositions.

#### **61.1.1 Preventive Wound Management** [4]

Wound management begins right after the soft tissue injury in the primary or acute stage.

#### **Post-traumatic scarring can be reduced considering the following measures:**


*Soft tissue injuries/scar revision/soft tissue and hard tissue reconstruction related to management of residual deformities have been dealt in detail in respective chapters of this book (refer Chaps.* 36, 49, 86 and 88*). Wound care and management begin with preventive measures.* 

#### **61.1.2 Volume Issues in Deformities** [3]

This section briefy discusses management of volume defects using tissue expanders. Volume issues are to be considered with all excision techniques. Loss of tissue volume due to trauma or contraction of the scar may lead to depression and

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1303

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_61

Department of Oral and Maxillofacial Surgery, Tagore Dental College and hospital, Chennai, India e-mail: jimsons@tagoredch.in

distortions that are more obvious than the original scar. Such loss of tissue may require volume replacement that can be achieved by other techniques. Surgical faps may be commonly used to fll the tissues. Likewise, biological fllers can also be taken into consideration in managing depressed or irregular areas. Tissue debulking can be done whenever there is an excess of tissue volume.

Two methods of tissue transfer can be opted whenever there is loss of tissue: a free skin graft and a skin fap. A free skin graft of limited thickness involves the complete removal from the donor site and then placement on the recipient site for survival. This type of graft will not survive in avascular recipient sites. A skin fap with underlying subcutaneous tissue will carry its blood supply necessary for the survival of the fap. These skin faps are further divided into local faps or distant faps (from distant sites). Single-stage transfer of faps may be done with microvascular surgical techniques (Chart 61.1 shows types of soft tissue deformities with relation to the volume defects).

#### **61.1.2.1 Minor Loss of Tissue** [3]

**Chart 61.1** Types of soft tissue residual deformities


#### **61.1.2.2 Major Loss of Tissue** [3]


©Association of Oral and Maxillofacial Surgeons of India


#### **61.1.3 Tissue Expanders** [4–6]

Tissue expanders are the advised treatment technique when the loss of tissue or the scar surface areas are larger. It is indicated in revision or excision of scar where local or regional faps may not be feasible to be used in the immediate reconstruction. Although commonly employed for tissue expansion in forehead and scalp, it may be benefcial for any areas with larger defects. Tissue expansion becomes an ideal choice in the scalp due to its inelasticity. It allows replacement of defects with adjacent surrounding tissue which is similar in colour, texture, adnexal structures and innervation (Fig. 61.1)

**Fig. 61.1** Schematic representation of a tissue expander

#### **61.1.3.1 Properties of Tissue Expanders**  [4, 5, 7–9]

Silastic balloons with self-sealing valves which are used as tissue expanders are implanted beneath the skin.


#### **61.1.3.2 Biomechanical Properties**

During the period of tissue expansion, a capsule is formed, and the epidermis is thickened and expanded. Increased mitotic activity is seen evidently using the microscope during the expansion. The dermal thickness, which decreases during the expansion phase, returns to normalcy in 2–3 years. Expanders may also result in decreased adjacent muscle thickness, but without any loss of function. The adipose cells may decrease in number, and subcutaneous thinning may also be seen. Viability of expander is maintained with increased angiogenesis. Bone remodelling may also take place beneath

©Association of Oral and Maxillofacial Surgeons of India

the expander. The morphology and number of hair follicles are usually not affected, and hence this is a key in scalp expansion. Treatment duration can be reduced in areas where more than one expander can be placed. The gradual stretching of the tissue over the expanding subcutaneous tissue is called biological creep. Placement of the balloons and allowing a series of infations and defations to result in the stretching of the skin are the principles behind tissue expanders. This inherent nature of the skin to expand beyond its natural extensibility is referred to mechanical creep [4, 10].

#### **61.1.3.3 Technique**

Expanders are implanted by making incisions at the junction of the scar and the healthy tissue. A pocket is made in an avascular fascial plane. Wound closure is done with layers over the expander. 10% volume of expander may be added at the time of surgery to minimise chances of hematoma formation around the expander. Necrosis of the overlying tissues may occur if any wrinkles are present over the surface of the expanders. If the site allows area for placement for more than one expander, it may reduce the overall treatment duration. Two weeks after placement, the expanders are infated once or twice in a week. Patient discomfort or blanching over the surface of expander should be observed. Overexpansion of tissue is necessary as there will be a degree of contraction after removal of the expander. Likewise, bony contour changes usually regress without any intervention. The capsule of the expander is released along its margins but is left intact (Fig. 61.2). Generally, a waiting period of 2 weeks should be observed before proceeding to the next stage of the surgery/procedure. This allows the skin tension to reduce before the next stage of the surgery [4, 5].

#### **Advantages**

Local usage of tissue by expansion helps in the preservation of the sensation, vascularity and the adnexal structures. This aids well in both aesthetic and functional aspects.

#### **Disadvantages**


#### **Complications**


**c**

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 61.2** Conventional method of tissue expander in management of scar tissue. (**a**) Expander placed near scar tissue and tissue expansion seen. (**b**) Adjacent scar tissue removed before closure. (**c**) Overexpanded tissue closed with adjacent scar tissue removed and the capsule is left intact with release along its margin

This chapter further discusses the use of grafts in residual deformities, management of hard tissue residual deformities and recent advances.

#### **61.2 Grafts in Residual Deformity**

Soft tissue and hard tissue defects are best managed by the use of grafts. Secondary or residual use of grafts and faps is essential in restoring the hard tissue and soft tissue defects. The scope of this chapter briefy describes grafts used in residual deformities. This section also outlines the

**Chart 61.2** Essentials in biology of bone grafting

biology behind bone grafting and types of bone grafts (Chart 61.2).

#### **61.2.1 Ideal Characteristics of Bone Graft Material** [11]


#### **61.2.2 Biology of Bone Grafting**

Biology of bone grafting includes the following rationale [12–17] (Table 61.1):



**61.2.2.1 Types and Tissue Sources for Grafting**  (Table 61.2 and Chart 61.3)

#### **Boyne's Ideal Characteristics of Bone Grafts [18]**


Grafts play a major role in primary or secondary/residual management, eventually playing plays a vital role in reconstruction. Bone grafts in residual deformities are ideal to fll volume defects and also aid in reconstruction. Various types and sources of grafts have already been listed (Chart 61.3).


#### **61.2.3 Bone Grafts in Hard Tissue Residual Deformities**

#### **61.2.3.1 Nasal Deformities** [19]


#### **61.2.3.2 Orbital Deformities** [19]


©Association of Oral and Maxillofacial Surgeons of India

**Chart 61.3** Sources of bone grafts

• Orbital foor implants are used by manual adaptation of implants according to the contour of the damaged site. However, custom designed implants with computerguided surgical planning is best utilised in management of late deformities as there is time to assess, plan, design and custom manufacture the precise implants. Orbital titanium implants can also be manufactured by this method.

#### **61.2.4 Alloplastic Materials** [19–24]

Alloplastic materials have been used in surgeries since 1930s, and newer materials are available since then. Prime advantages of alloplastic materials are reduced donor site morbidity, easily usable, good patient compliance and shorter working time compared to autogenous grafts. Sources and types of graft materials are listed in Chart 61.3.

#### **Goal of Alloplastic Materials**


Their role in maxillofacial reconstruction is still controversial. These porous alloplastic materials are high-density polyethylene implants that are very stable and fexible in nature and also help in new vascular and tissue growth within. This makes alloplasts an essential commodity in management of maxillofacial defects and also in reconstruction.

Alloplastic materials used in the region of defects for reconstruction are available in various forms like titanium mesh, porous polyethylene (Medpor) and PEEK (poly ether ether ketone) which can be customised as needed. *Medpore (stock)* can be manipulated and adapted in situ according to the defect. It is also possible to make *custom-made Medpore, silicone and PEEK* with the computer-aided designing. Even though they are known to produce good clinical outcomes, it may be predisposed to infection. Careful handling, understanding patient's history and surgical placement are essential to avoid any complications or to manage any failures. Medpore along with fat grafting may serve to restore the contour as well as the volume. These custom-made implants are widely used in management of defects and deformities as part of maxillofacial reconstruction. Applications of MEDPORE are chin augmentation procedures, correcting congenital deformities and improving aesthetic outcome in nasal, subnasal, paranasal, malar, orbital, and mandibular (angle and body) areas. It is essentially suited for midfacial contouring in patients treated for cleft. The use of these alloplastic materials ideally helps to establish three-dimensional anatomical harmony in correcting defects. Polyether ether ketone (PEEK) is another valuable alloplastic material that precedes with advantages similar to that of Medpore Custommade patient-specifc PEEK implants have proven to offer excellent facial rehabilitation. The durability and malleable property of PEEK make it a biomaterial of choice for maxillofacial surgeons with which complex maxillofacial defects following trauma or neoplastic can be corrected. Often, the use of alloplastic materials may be an adjunct or combined with prosthesis to further complete the facial rehabilitation process.

#### **61.2.5 Use of Grafts in Associated Residual Structural Damages**

Traumatic or iatrogenic reasons causing structural or residual damages are areas of concern during maxillofacial surgery. Important structural damages involving nerve tissues, salivary gland apparatus and nasolacrimal system should be identifed and best managed during the primary surgery. If left untreated, secondary or delayed management leads to further complications. It is the skill of the surgeon to carefully carry out the surgery with no or minimal trauma to adjoining structures, and it is experience that will help to predict any relative functional damages and manage it accordingly.

*Nerve Injuries:* Injuries to the peripheral branches of the trigeminal nerve following maxillofacial trauma or surgery often result in sensory and functional problems. Spontaneous recovery of inferior alveolar nerve and infraorbital nerve after facial fractures depends on a number of factors like age, gender, fracture displacement, site, type of management and time interval between injury and management. Localisation and determination of the pattern of injury of trigeminal nerve are done by careful examination of the neurosensory dysfunction (NSD) of sensory dermatome of trigeminal nerve. It may be very diffcult in establishing the exact cause in secondary NSD damages. Such residual defects due to injuries can be from nerve compression due to displaced old fracture segments, laceration due to fracture components, dislocated nerve from a displaced fracture, and compression due to soft tissue oedema or secondary ischemia. Injuries may also be related to crushing, avulsion and partial or total nerve transection [25–28].

Determining the exact aetiology of post-operative residual or secondary NSD damage is diffcult, and the best way to manage is assessing the damage during the primary surgery. Accessing and operating the site for correction secondarily may itself cause further damage if not handled properly. Nerve grafts can be used in the management of such damages. It involves microsurgical repair of nerve that requires reconstruction of any continuity defect using an autogenous nerve graft (*donor site—sural or great auricular nerve*). Microsurgical repair helps in improving the clinical outcome in such conditions. Nerve allografts have proven to be successful in improving the neurosensory recovery. Allografts are further benefcial as it alleviates the donor site morbidity. Ichihara et al. suggest the use of alloplastic tubes in short span nerve defects as artifcial nerve guides. However, studies need to ascertain their use in long span trigeminal nerve defects. Similar use of autogenous and allogenic grafts is applicable for facial nerve injury as well. The successful outcome of grafts depends on the length/size of the defect and patient factors like age/gender/nutritional status, and it is also important to address factors like previously irradiated sites [29–32].

*Salivary Gland/Duct Injuries:* Trauma, lacerations, deep injuries and iatrogenic injuries in the parotid region can result in injuries to the important related structures like the buccal branches of facial nerve, Stenson's duct and transverse facial artery and vein. Surgical and non-surgical management of injuries to the salivary gland or its duct is done to improve the clinical outcomes. Non-surgical management includes the use of anti-sialagogues, elastic bandages and reduced oral intake until the defect heals. Microsurgical repair may be done to preserve remaining ductal structures using autologous vein grafts. Reconstruction of the duct is done using autologous vein grafts like saphenous vein, antebrachial vein, facial vein, etc. Alloplastic Gore-Tex has been used, and the outcome was found to be similar to anastomosis in autologous vein grafts in parotid duct reconstruction. Gore-Tex tube carries advantages like decreased graft morbidity and shorter operation time. Timely correction of salivary ducts is important to avoid complications like sialocele, salivary fstula, etc. [33–38].

*Nasolacrimal Duct Injury:* It is important to reconstruct the nasolacrimal system if damage is seen following orbital or midface trauma. It is similar to other ductal and nerve management. The nasolacrimal duct system can be reconstructed with autogenous and allogenic grafts. Greater saphenous vein can be used as autogenic grafts in such cases. Buccal mucous membrane grafting also shows improved outcomes in removing obstructions in the ducts. Silicone stent intubation is also used in the repair of damaged nasolacrimal duct. Primary management is essential in this condition since delayed management may be diffcult to carry out [39–41].

#### **Future of Grafting**

Future in grafting promises advances in gene therapy, tissueengineering, and 3D scaffold. It has created greater perspective with the inclusion of growth factors, stem cells and biological scaffolds that will help in production of laboratoryengineered tissue substitutes in oral and maxillofacial surgery.

Three-dimensional (3D) computed tomography (CT) has brought major changes to visualisation, planning and treatment of maxillofacial defects ever since its introduction. The scanning and surgical planning software have advanced in such a way that a surgeon can meticulously plan a patient-specifc protocol to carry out procedures effectively. Preformed and custom printed alloplastic has more accuracy, reduced operative time and a predictable outcome in management. However, conventional implants require intraoperative adaptations and longer duration of operation. All these have been possible with the advances in reconstructive surgeries with CAD-CAM (computer-aided designcomputer-aided modelling) software. Such major advances will lead to further improvement in patientspecifc implants (PSI) in the three-dimensional management of defects in reconstructive procedures [23, 24, 42, 43].

### **61.3 Hard Tissue Deformities**

Deformities in the maxillofacial bones are due to a variety of causes like pathology, trauma, infection and congenital disabilities. Residual deformities are such defects that are observed even after the primary surgical management and need further cosmetic and functional intervention for an outcome. The size of the defects in the maxillofacial region may vary from small alveolar clefts and nasal deformities to maxilla-mandibulectomy-type defects. Restoration of the deformities to its closest healthy anatomical structure and their essential functioning are the primary goals of any reintervention procedure.

Any defect (size, shape, position or amount) of the osseous structure can be replaced by reconstructive surgery. The aim is to replace it with the missing structure, i.e. the bone. Various types of bone grafts may be used for this purpose. Correction of soft tissue defects needs a complete understanding of the wound healing biology. Likewise, in hard tissue deformities, it is essential to know the bone physiology, immunology and surgical principles to make the reconstruction a successful procedure.

#### **61.3.1 Patient Assessment**

Although general rule implies to replace or reconstruct the lost osseous defect, it is important to evaluate every patient thoroughly before proceeding with any intervention. Analysis should include evaluation of hard tissue and associated soft tissues. When accompanied by soft tissue deformities, it is important to treat with caution considering the soft tissue changes over time as well [44].

#### **61.3.2 Residual Mandibular Deformities**  [3, 45–50]

General Assessment Points for Mandibular Defects:


Causes for Post-traumatic Mandibular Deformities:


Residual Deformities in Mandible:

	- Diffculty in speech
	- Diffculty in swallowing
	- Drooling of saliva
	- Un-aesthetic appearance

#### **61.3.2.1 Deformity in the Ascending Ramus of the Mandible**

No treatment is often required if the occlusion is satisfactory. Complete fusion of the bony segments to the temporomandibular joints may occur following the destruction of the developing mandibular condyle after trauma or secondary infection. In this case, the destruction of the articular disc allows the contact between the bony fragments of ascending ramus and the glenoid fossa, fnally resulting in ankylosis. When this occurs in children bilaterally, it shows reduction in lower third dimension resulting in appearance called "Bird Face deformity". This usually results in aesthetic and airway concerns, and psychological disturbances. Airway disturbances should be viewed with greater importance. Ankylosis in adults will result in occlusal abnormalities and diffculty in enunciation of speech and communication. Sometimes pseudo-ankyloses may also be observed.

#### **61.3.2.2 Surgical Options for Post-traumatic Residual Deformities**

Post-traumatic deformities include *non-union, malunion/ malocclusion and facial asymmetry*, and they may require secondary correction. These deformities can occur alone or in conjunction, sometimes as a sequel to a deformity.

#### **61.3.2.3 Non-union** [45–50]

They are fractures with arrested healing that requires further surgical treatment for correction. It is considered to be non-union when a fractured segment is mobile for 4 weeks without treatment or 8 weeks after surgical treatment.


Diagnostic considerations:

Clinical Examination:


#### Radiographic Findings:

Irregular radiolucency with mottled fracture ends.

#### Management:


and then reconstruction plates are fxed with the help of screws away from the fracture.


#### **61.3.2.4 Malunion/Malocclusion:** [46, 51, 52]

It can occur in any type of mandibular fracture when segments heal in improper alignment. Malunion is often due to inadequately established occlusion, inadequate anatomic reduction and poor adaptation of fixation plate.

Figs. 61.3, 61.4, 61.5, and 61.6 depicts malocclusion related management of deformities.

#### Diagnostic Considerations:

It is often diagnosed with malocclusion and more associated with rigid internal fxation. Dental models are used to study and plan the occlusion.

#### Management Considerations:


**Fig. 61.3** Malocclusion following trauma surgery with multiple loss of teeth in mandible and associated osteonecrosis. Patient managed with iliac grafting of mandibular osteonecrosis site, followed by implant rehabilitation and vestibuloplasty. Preoperative radiograph. (**a**) Panoramic radiograph (**b**) Cone beam computed tomography scan.

(Reference for Figs. 61.3, 61.4, 61.5, and 61.6) (http://creativecommons.org/licenses/by/4.0/), Kim SY, Choi YH, Kim YK. *Maxillofac Plast Reconstr Surg*. 2018;40(1):27. Published 2018 Oct 15. doi:10.1186/s40902-018-0167-z (springer open)

**Fig. 61.4** Clinical intra-oral photograph showing. (**a**) Iliac bone harvesting. (**b**) Grafting of the harvest iliac bone into the mandible defect

**Fig. 61.5** Post-operative OPG

**Fig. 61.6** Post-operative OPG after implant placement for dental rehabilitation

#### **61.3.2.5 Early Malunions**


#### **61.3.2.6 Late Malunions**


#### **61.3.2.7 Malunions/Malocclusion and Condylar Fractures** [53–56]

• Majority of condylar fractures when treated "closed" may develop malunion. However, condylar malunion may not always cause malocclusion.

• Quality of the functional rehabilitation of the mandible is an more important factor than the type of treatment (closed or open).

#### Diagnostic Considerations:


#### Treatment Considerations:


#### Management Considerations:


#### **61.3.2.8 Facial Asymmetry** [46]


Diagnostic Considerations:


#### Management Considerations:


surgical planning. Asymmetry is corrected, and new occlusion is verifed with new fxation. The procedure similar to principle treatment. Additional osteotomy may be required depending on the type of original injury.

#### **61.3.2.9 Principles of Mandibular Reconstruction** [45, 57]

*Reconstruction of larger defects of the mandible is discussed in Chap.* 88.

Marx and Saunders listed the goals of mandibular reconstruction in order to consider a grafting procedure successful.


### **61.3.3 Midface Deformities** [3, 58]

The midface is a critical zone of the maxillofacial region concerning both aesthetics and function. Midface includes structures like the maxilla, palate, orbit, cheek, upper lips, eyelid and nose. It is often an area that poses a signifcant challenge to a maxillofacial surgeon for reconstruction. Orbit is usually challenging to reconstruct in secondary setting mainly due to chances of scarring. Due to the diffculty in obtaining good results in primary surgery, the nose and auricle are best considered for correction in a secondary setting. Figure 61.7 shows areas of the midface.

**Objectives in Correcting Midface Deformities [58]**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 61.7** Highlighted (yellow) areas represent midface region

Indications to Correct Midface Defects [58]


#### Diagnostic Workup: [58]

Treatment planning for midface changes requires careful planning and knowledge of previous treatments to achieve the best result.

• Evaluate general status of the patient (age, history of tobacco, alcohol abuse, nutritional status, and presence of co-morbidity)


During the workup, it is necessary to eliminate cases of unresectable conditions like distant metastasis or recurrence in oncology or non-traumatic cases.

#### Diagnostic Assessment: [58]

Assessment requires evaluation of surface or volume of missing tissues. Assessment should include evaluating defects in the bone, skin, musculature, innervation and mucosa (Chart 61.4).

#### Treatment Options: [3, 58]

Surgical correction in this region varies from prosthetic replacement to complex microvascular reconstructive surgeries.

Surgical Options:


**Chart 61.4** Diagnostic assessment

• Critical evaluation is to be done in previously irradiated or operated midfacial defects.

*Current methods under development include tissue engineering for ideal regeneration of the tissues in head and neck defects. Facial transplantation has also paved newer paths in this feld, but indications are restricted.*

#### Other Non-surgical Options: [58]

*Maxillofacial prosthesis*:


#### Ancillary Procedures: [3, 58–61]


#### Oral Rehabilitation:


#### **61.3.4 Residual Maxillary Deformities** [3, 58]

#### **Goals in Correction of Maxillary Deformities**


Common Maxillary Deformities May Be Due to:


Essentials for Treatment Planning:


#### **61.3.4.1 Immediate Repositioning of Maxilla and Midface Complex**

Open Surgical Immediate Mobilisation Treatment: This is indicated in conditions where total mobilisation is not possible. These are cases that are treated after 6 weeks or more after trauma, or even years later, usually cases where partial or complete consolidation has already taken place. The principle of surgical treatment is often the same as in the treatment of primary maxillary and midface treatments.

Old Fracture Segments: Old fracture segments in the anterior maxilla can be corrected by techniques described by Wassmund (1935) and Wunderer (1962) in cases of protruded maxilla. It is key to observe any scars in the labial vestibule as that may affect the vasculature to the alveolar process. Wassmund's method should be preferred when a scar is present; otherwise, Wunderer's method may be followed in which maintenance of labial blood supply is essential. In contrast, Schuchardt K suggested a single-stage technique which involved an osteotomy of the lateral alveolar process and relocation to its original alveolar location [62–64].

#### **61.3.4.2 Old Le Fort I and II Fractures** [3]

Untreated Le Fort I Fractures: An incision may be made at a point horizontally through lateral and anterior maxillary sinus walls. Osteotomy is done to ensure that the plates are placed on both sides of the stable bone region. Line of osteotomy does not precisely follow the line of fracture.

Old Le Fort II Fractures [3]: If there's no cosmetic signifcance or less damage to the nasal region—similar procedure may be followed. Le Fort II osteotomy is indicated when the nose has sunken, and the midface is shortened.

In the above scenarios, Le Fort I and II osteotomies may be done when either occlusion needs to be restored or there is an aesthetic concern. Bone grafts may be used in the region of the bridge of the nose below the buttress and also between pterygoids and the maxillary tuberosity if possible (Figs. 61.8 and 61.9).

#### **61.3.4.3 Displaced Edentulous Maxilla** [3]


#### **61.3.4.4 Old Le Fort III Fractures** (Figs. 61.10 and 61.11)

Le Fort III osteotomy is indicated in old Le Fort III fractures when the deformities may be seen in the entire midface region with dislocations in orbital margins and zygoma. Unilateral osteotomy may be indicated when only one side of the face is affected. Occasionally in cases of comminuted fractures of the midface, a Le Fort I osteotomy may be needed to be done along with Le Fort III osteotomy procedure. This is essential to correct the occlusion in untreated midface fractures. It may be challenging to carry out a re-treatment for comminuted midface fractures. Segments may be stabilised separately considering the complex nature of the fracture. The procedure can be simplifed by frst mobilising the entire midface complex with Le Fort III osteotomy and then followed by Le Fort I osteotomy (Figs. 61.12, 61.13, 61.14, 61.15, and 61.16 shows surgical management of a mid face deformity by onlay grafting; All images 61.12–61.16 are from the same patient) (Figs. 61.17, 61.18, and 61.19 shows clinical images of management of post operative malocclusion; all images 61.17–61.19 are from the same patient).

*Maxillary mobilisation can classified into gradual and immediate repositioning. Gradual repositioning of maxilla & midface complex were opted in cases where cicatricial fixation had already taken place. Gradual repositioning of midface/maxilla fractures using elastic traction, headframe, roll extension method, orthopaedic apparatus are mentioned here with respect to the historical perspective of therapeutic options. However, those methods are not current in usage.*

©Association of Oral and Maxillofacial Surgeons of India

**Chart 61.5** Historical perspectives of therapeutic options for maxilla and midface correction [3]

©Association of Oral and Maxillofacial Surgeons of India

#### **61.3.5 Post-traumatic Hypertelorism** [3, 44, 65–71]

It is a complication that may arise in fractures of midface complex when there is a dislocation of one or both orbits. Treatment is similar to congenital hypertelorism, and procedure may follow as suggested by Tessier et al. (1967). Stereolithographic models are best used for treatment planning. Although Tessier developed the extra and intracranial approach to correct the deformity, it was further refned later by Tessier, Converse, Van der Meulen et al., Monasterio **Fig. 61.9** Schematic diagram showing post-operative scenario following combined Le Fort 1 and Le fort II. Defects as a result of repositioning shaded as brown are areas to be flled with bone graft

©Association of Oral and Maxillofacial Surgeons of India

et al. and Marchac et al. They were able to visualise the bony orbit in two parts with the outer square box containing the globe and the inner cone housing the optic nerve. It was established that if these two parts could be separated, the outer box can be moved without affecting the vision.

*Goals of surgery for hypertelorism include:*


#### **61.3.6 Residual Zygomatic Deformities** [3, 58]

Periorbital area is often a zone of interest in the midface region from a functional and aesthetic point of view. An imbalance in this region could result in aesthetic concern and altered vision. This can be due to malunion of the fracture of the zygomatic complex. Any untreated fracture for longer than *10 weeks* is considered to be an *old fracture* and results in malunion—a stage at which a procedure needs to be done to correct any deformity.

#### **Clinical Signs and Symptoms**


Soft tissue damage like a torn lateral canthal ligament, malpositioned zygomatic bone, zygomatic arch or fragments of the orbital arm may result in an asymmetry of the lateral midface. Corrective surgeries may be required in case of a destroyed orbital bone as well. More often, patients visit the surgeon for aesthetic reasons. It may be often diffcult to correct aesthetics when it involves post-traumatic deformities in the malar prominences (Table 61.3).

#### **61.3.6.1 Associated Defects of the Orbital Zone** [3]

• *Dislocated eyeball*: Usually occurs as a sequel to zygomatic fractures, and slight dislocation may be seen after primary treatment. Displaced orbital foor due to enlargement of the socket or the loss of the orbital content due to

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 61.10** Schematic diagram showing old untreated Le fort III fractures

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 61.11** Schematic diagram showing post-operative following combined Le Fort I and Le fort III. Defects as a result of repositioning shaded as brown are area to be flled with bone graft

**Fig. 61.12** Midface deformities showing residual deformities. (**a**) preoperative extra-oral photograph showing facial asymmetry, depressed malar prominence (right side), and incompetent lips. (**b**) Post-operative extra-oral photograph. (Reference for Figs. 61.12, 61.13, 61.14, 61.15,

and 61.16: Ranganath K, Hemanth Kumar HR. The correction of posttraumatic pan facial residual deformity. *J Maxillofac Oral Surg*. 2011;10(1):20–24. https://doi.org/10.1007/s12663-010-0088-6) *springer publishers*

intra-oral photograph showed deranged occlusion with right anterolateral open bite. (**b**) Post-operative intra-oral photograph

**Fig. 61.14** (**a**) Post-operative PNS radiograph. (**b**) Post-operative orthopantomograph

**Fig. 61.15** (**a**, **b**) Sculptured iliac bone onlay graft

**Fig. 61.16** (**a**) Onlay graft positioned on the patient. (**b**) Onlay graft plated to the maxilla

**Fig. 61.17** Patient complains of open bite, malocclusion, deviation of maxilla and TMJ tenderness after trauma surgery. Preoperative OPG showing malunion in maxilla and malocclusion. (Reference for Figs. 61.17, 61.18, and 61.19: Kim, Sang-Yun et al. "Post-operative malocclusion after maxillofacial fracture management: a retrospective case study." Maxillofacial plastic and reconstructive surgery vol. 40,1 27. 15 Oct. 2018, https://doi.org/10.1186/s40902-018-0167-z. (http://creativecommons.org/licenses/by/4.0/), springer open

**Fig. 61.18** Photograph during the operation. (**a**) Shows severe malocclusion before second operation. Arch bar placed for intermaxillary fxation. (**b**) Fracture site exposed, malunion segments detected

**Fig. 61.19** Le fort I osteotomy done under general anaesthesia to resolve malunion and malocclusion. TMJ pain resolved following the treatment. (**a**) Post-operative (1 month) photograph showing resolution of malocclusion. (**b**) OPG after 1 month. (**c**) OPG 1 year after operation

soft tissue displacement or necrosis may result in enophthalmos and/or downward displacement of the globe.


Indications for Surgery: [3]


**Table 61.3** Radiographic assessment for detecting malunion at fracture sites



Surgical correction of traumatic zygomatic complex fractures is discussed in Chap. 56.

#### Treatment options: [3] (Chart 61.6) (Table 61.4)

*Surgical approach is decided once the operative procedure has been fnalised. Common approaches include* [3]:


## Complications: [3]

	- Fracture of bone at the optic canal
	- Misplaced implant that may result in compression of nerve

#### **61.3.7 Secondary Orbital Reconstruction** [5, 72, 73]

Post-traumatic secondary deformities include:


Both deformities are diffcult to correct.

Factors Responsible for Globe Malposition:


Factors Responsible for Enophthalmos:


Rotated and displaced zygomatic bone leads to separation of the structures from its normal articulation with the greater wing of the sphenoid and maxilla. A substantial increase in the volume of the orbital cavity is accompanied by fssures along the foor and lateral wall of the orbit. Also, nasoethmoidal fractures can result in canthal distortion and mal-

©Association of Oral and Maxillofacial Surgeons of India

position. Telecanthus and canthal height distortion can be diffcult to correct if there is a signifcant loss of soft and hard tissue.

Any excess or defciency in the horizontal position of the globe is called dystopia and is easier to correct. Inferior displacement (horizontal displacement) is managed by augmenting the sub-periosteum of the anterior orbital wall, anterior to the axis of the globe. This technique helps to produce superior movement of the eyeball but does not correct enophthalmos even with the overall decrease in orbital volume [5].

**Table 61.4** Surgical options for zygomatic residual fractures [3]


#### Enophthalmos: [5]

Managing post-traumatic secondary enophthalmos involves reducing the volume of orbital cavity posterior to the globe axis. The three-dimensional anatomy of both external and internal structures of the bony orbit should be restored effciently by refracturing and rearticulating the skeletal framework (including zygomatic bone).


Complications in Correction of Enophthalmos: [12, 74]


Telecanthus: [74]


#### **61.3.8 Nasal Deformities** [3, 75]

Residual nasal deformities occur as a consequence of the displacement of bony and cartilaginous components of the nasal skeleton. The basic anatomy of the nasal skeleton includes the nasal bone and the cartilaginous part of the nasal septum. The frontal process forms the lateral walls, and the vomer forms the osseous part of the nasal septum. The nose is the most commonly traumatised area due to its prominent central location and its elevation from the frontal facial plane. However, secondary deformities to nasal trauma are not rare [3].

#### **Reasons for secondary nasal deformities** [75]


#### • Unstable bony and cartilaginous structures due to fracture • Poor nasal septal management—


### **61.3.8.1 Potential Complications Associated with Nasal Deformities** [3] (Chart 61.9)

Clinical Evaluation: [3, 75]

The patient needs to be aware and educated on the options for a secondary rhinoplasty to correct the residual nasal deformities as the pathology may concern the functional and cosmetic needs of the patient.


#### Preoperative Examination: [3]

	- Deformity
	- Symmetry

Morphological Considerations: [3]

	- Shape/contour
	- Prominence of the nasal bridge

*It is important to evaluate the injury as it may be related to* [3]


*are discussed in brief*


#### **61.3.8.2 Deformities of the Nasal Bridge or Nasomaxillary Region** [3]

Deformities involving the nasal bridge and lateral walls of the nose not extending into the frontal or orbital regions.

©Association of Oral and Maxillofacial Surgeons of India

**Chart 61.9** Potential complications associated with nasal deformities

Pathogenesis:


Clinical Features:


#### *Nose:*


Surgical Approach for nasal deviation:


#### **61.3.8.3 Depression of Nose** [3] **(Saddle-Shaped Deformity)**

Treatment differs based on extent of the deformity along the nasal crest (entire length or lower half).


#### **61.3.8.4 Depression of Lower Half of Nasal Crest** [3]

Two types of concepts are followed in treatment of such deformities:


#### **61.3.8.5 Naso-Orbital Deformities** [3]

Deformities not only involving the nasal pyramid but also affecting the ethmoid and maxillary components.

Pathogenesis:


#### Anatomical Characteristics: [3]

*Frontal process of the maxilla––*


Clinical Features: *Nasal crest––*


#### **Essentials in Correcting the Deformity:**


#### **61.3.8.6 Surgical Management**

Key Points in Treatment:


#### **61.3.8.7 Nasofrontal Deformities** [3]

Deformities due to secondary post-traumatic lesions involving not only the nasal pyramid but also the nasal base and area of the frontal bone. Concentration of injuries at the nasofrontal angle is proportionate to the degree of violence encountered, thereby resulting in fractures and displacement of tissues.

#### *Nasofrontal angle profle is affected by*


#### **Pathogenesis:**


*Lesions on anterior wall––*


*Lesions of posterior wall––*


*Associated lesions––*


#### Clinical Features:


*Associated pathological changes––*


Essentials in Surgical Management:


*The principles of the management of nasofrontal deformities in delayed conditions are similar to managing post-traumatic nasofrontal deformities but should be done with caution and must address associated complications seen at the stage of delayed management. In case of nasofrontal deformities, it is important to address post-traumatic dehiscence of frontal sinus wall in delayed management cases. Certain degree of bone loss due to resorption is seen during the post-traumatic phase, and this may increase when the management is delayed. Hence, in such cases it is important to be cautious in resection of minimal tissue of the posterior wall, and it needs to be carefully performed. Reconstruction of the anterior wall with bone grafts may be done, also including the orbital roof and the ethmoidal region if necessary* [3]*.*

#### **61.3.8.8 Naso-Fronto-Ethmoidal Deformities** [3]

Deformities involving the nasal bony mass are caused due to greater degree of force. The impact may extend as far as the ethmoid bone which forms the upper wall/roof in the posterior part**.**

Pathogenesis:


Clinical Features:


Essentials in Management of Naso-Fronto-Ethmoidal Deformities:


#### **61.3.8.9 Delayed Management of Orbital Hypertelorism and Naso-Orbito-Ethmoidal (NOE) Fractures** [73, 75–77]

Acute trauma in the naso-orbito-ethomoidal region could result in chronic orbital and naso-orbital deformities. It is important to be aware of the acute injury to correct the deformity that will be established later. Secondary late corrections in cases of severe orbital hypertelorism may be very diffcult to correct. The severity of orbital hypertelorism can be assessed with the help of Tessier score.

Traumatic orbital hypertelorism due to NOE complex fractures

*Goals of management*:


Surgical Management:


#### **61.3.8.10 Secondary or Delayed Management of Orbital Hypertelorism Associated with NOE Complex Fractures** [75–77]

• Goal is to restore the normal interorbital distance.

• Acute management of chronic long-standing deformities is essential. It is very diffcult to correct severe orbital hypertelorism, especially in cases which includes intracranial osteotomies. Such cases are associated with increased post-operative morbidities. Subcranial osteotomies may be opted in milder cases.

• Aesthetic and functional outcomes in late correction may not be satisfying, and hence the best strategy is to repair the deformities as early as possible following the first injury and hence not delay the treatment.

#### **61.3.8.11 Conclusion**

• Repair and reconstruction of nasal deformities are often challenging and technique sensitive for the surgical team (maxillofacial and neurosurgical). It is emotionally and psychologically challenging for the patients as well. Hence, it is essential to identify the pitfalls and carefully carry out the surgical treatment plan. Sometimes, further revision may be necessary even with the best planned surgical procedures. Therefore, it is important for the surgeon and the patient to understand the limitations of the available surgical techniques.

#### **61.4 Post-oncological Deformities**

Management of Post-oncological Deformities:

Post-oncological deformities here refer to the soft tissue and hard tissue defects that may be encountered following a primary treatment. Unlike a primary cosmetic therapy, predicting the result of an oncological treatment is often more technique sensitive and should be considerate in establishing the overall physical and mental well-being of the patient. Management of deformities should also aim at a comprehensive functional, aesthetic and social well-being of the patient.

Reconstruction of soft tissue and hard tissue structures following trauma or oncological surgical therapy is primarily essential. Correction of the residual deformities should be carried out along with the principles of reconstructive management.

*Reconstruction generally includes the following steps in management* [78]:


We have already discussed in detail the use of above methods in management of traumatic residual deformities in this chapter.

Recurrences, untreated tumours and metastasis which are considered to be residual in nature after primary management are not considered under management of postoncological deformities. It is important for the surgeons to be more accurate with the surgical margins when surgically operating malignancies. Any re-surgical procedure for recurrence or deformities is often challenging due to factors like previously irradiated areas, previously operated surgical feld, under nourished status due to the pre-existing malignant condition and also due minimal surgical options for such patients.

Residual deformities associated with post-oncosurgery results in external facial disfgurement/defects, intra-oral defects and also changes that may affect certain functions. These deformities are often relative to structures which were primarily involved and their corresponding functional deformities. Deformities occurring following surgical treatment of head and neck oncology usually require reconstruction procedures as the complete removal of tumours with margins may involve increased loss of soft or hard tissues.

#### **61.4.1 Lip Deformities** [79–83]

Post-oncosurgical defects of the lip are often seen with loss of tissues. Management of such defects is usually considered according to the size of the defects. Secondary deformities of the lower lip after reconstruction are described in (Table 61.5), and they need to be treated accordingly with cosmetic surgeries. *Lip reconstruction is discussed in soft Tissue reconstruction chap.* 86.

**Table 61.5** Secondary deformities of lower lip following reconstruction


#### **61.4.2 Management of Intra-oral Defects Involving Floor of the Mouth and Alveolar Ridge Tumours**

Defects in these regions are relative to the size of tissues lost and may be corrected with augmentation and reconstruction procedures.


#### **61.4.3 Management of Defects of Oropharynx**

Oropharyngeal defects are managed with primary closure, skin grafts, local pedicle faps and microvascular-free faps. Current goals in reconstruction include restoration of the function and closure of defects as well.

#### **61.4.3.1 Management of Soft Palate Defects** [88]


• *Large or extensive palatomaxillary defects* are managed with obturator prosthesis or with vascularised osteocutaneous free faps.

#### **61.4.3.2 Management of Tongue Defects** [89, 90]

Tongue defects are usually diffcult to treat and reconstruct. Management of tongue defects primarily involves improving the functional outcome.


#### **61.4.3.3 Management of Posterior Pharyngeal Wall** [90]

• Primary closure with/without split thickness skin graft is used for closure of small defects. Free fap reconstruction is necessary for large defects.

#### **61.4.4 Deformities Associated with Intra-oral Disfgurement** [91–98]

The primary goal in surgical management of oral tumours is to gain surgical access for assessment and visualisation of margins and anatomic relations for resecting the tumours. Surgical margins are vital in establishing a tumour-free zone. Although it is important to have a follow-up on recurrence of tumours and metastasis, it is the complex nature of the oral cavity and head and neck anatomy that requires careful yet skilful management of the adjacent normal tissues by proper closure and post-operative management.

The goal earlier was to achieve access to the tumours, but now it also involves incisions that will facilitate an aesthetic access to the pathology. Increased incidence of dehiscence and unaesthetic scar formation are common in neck incisions (with trifurcation extensions) that do not lie along the natural skin creases. Irradiated areas may cause worsening of scar appearance, or even superfcial necrosis may occur. Inadequate, delayed and infected tracheostomy may also result in an unaesthetic tracheostomy scar formation. Prevention of unaesthetic scars can be done by careful tissue handling. It is also essential to protect the skin from additional trauma due to traction, tension or electrocautery. Flaps with adequate vascularity further help to minimise the chances of unaesthetic scars. Following access through the lip to certain tumours in the oral cavity, the site requires to be exactly oriented and aligned with the vermilion lip border, as well as interdigitating orbicularis oris muscle, re-orienting lip skin and oral mucosa to replicate lip competence, aesthetics and function [92–97].

Even though reconstruction of maxillectomy defects is an option, maxillary defects can also be corrected with prosthetic obturators. Maxillary obturator provides adequate structural support to preserve speech, swallowing and essential mastication. Clinically, a good obturator can be fabricated only by the skills of a good prosthodontist [98].

It is important to evaluate any history that may contribute to poor wound healing and also lead to post-operative wound dehiscence and compromised fap vascularity resulting in improper scarring.

#### **61.4.5 Deformities Associated with Healing Tissues** [91, 92, 99, 100]

Surgical procedure involving the upper aerodigestive tract through neck incision may lead to fstula formation as a result of salivary leakage.

The formation of fstulas is contributed majorly due to:


Biological Factors that Contribute to Fistula Formation:


Signs and Symptoms of Fistulas:


#### Management:


#### **61.4.6 Functional Deformities Associated with Oro-Oncological Surgery**

*Surgical cancer resection may cause the following functional defects* [101]:


#### **61.4.6.1 Spinal Accessory Nerve**

Iatrogenic injury may cause "shoulder syndrome", for which physical therapy may help to improve the functional outcome. Pain, weakness of muscles, restrained shoulder movement, deformity of the upper extremity and inability to abduct upper extremity above 90degress occur due to denervation of trapezius muscle [91, 92, 102, 103].

#### **61.4.6.2 Phrenic Nerve**

Iatrogenic damage causes paralysis of ipsilateral diaphragm. It may even result in long-term pulmonary complications. Such damage can be prevented by limiting surgical dissection to the layer superfcial to pre-vertebral fascia and thereby prevent injury to nerve [92, 101, 104].

#### **61.4.6.3 Hypoglossal Nerve and lingual Nerve**  [92, 101, 104]


• Rehabilitation by physical therapy is often useful for improving the speech and swallowing.

#### **61.4.6.4 Vagus Nerve, Recurrent Laryngeal Nerve and Superior Laryngeal Nerve** [91]


#### **61.4.6.5 Sympathetic Trunk** [92, 101, 104]

Damage or disruption to the sympathetic trunk can result in ipsilateral Horner's syndrome. Careful evaluation is necessary to diagnose Horner's syndrome due to damage of nerve fbres, and it involves the following:


#### **61.4.6.6 Marginal Mandibular Branch of Facial Nerve** [92, 105]

Injury to This Nerve Causes:


#### Management:

Careful design and incision considering the anatomic location of the nerve during flap elevation help to prevent iatrogenic injuries and resultant deformities. It may take several months for neurosensory recovery when the neurologic injury is due to traction and not due to severance.

#### **61.5 Recent Advances**

#### **61.5.1 Endoscopy in Residual Deformitites**  [106, 107]

Recent trend in oral surgery includes the use of an endoscope to facilitate oral and maxillofacial procedures. Endoscopy techniques can be used in diagnosis and for treatment with minimal complications in many oral and maxillofacial surgical procedures like TMJ disorders, pathologies of jaw, nasal deformities, trauma and aesthetic procedures. The techniques and applications of endoscopy in oral and maxillofacial surgery are explained in detail elsewhere in this book. The advantages and applications of endoscopy-assisted maxillofacial surgical procedures make its usage a favourite option for maxillofacial surgeons. Minimal complications, good success rates and its effciency make endoscopy-assisted procedures a viable option.

The following are the best-known applications of endoscopy currently in oral and maxillofacial surgery:


Endoscopy-assisted minimally invasive technique is used in traumatic deformities like the following:

Orbital Floor Fracture: Requires trans antral approach. Care should be taken to protect the intraorbital contents like musculature, periorbita and optic nerve. Intraoperative conditions may necessitate the need for an additional periorbital approach during the surgery.

Mandibular Angle Fracture: Here, endoscopy can be used to fx the mandible with the superior and inferior plate with the best approximation possible. Endoscopic reduction helps in complete visualisation of the entire fracture line with inclusion of the inferior border. Management with endoscopyassisted surgery also reduces the risk of facial nerve injury. A single transbuccal trocar technique is used for positioning and fxation of the plates with easy visualisation of the fracture line. Some surgeons prefer a locking cannula for the precise placement of the fxation hardware. Endoscope is then used to confrm proper fxation and reduction, and it is then closed. Endoscope also aids in appropriate documentation of the procedure.

Sub-condylar Fractures: (Refer Chap. 54 on endoscopic approach for treatment of condylar fractures of mandible) Endoscopy can be applied in management of sub-condylar fractures by open technique, reducing risks of scars, fstula formation and facial nerve injury. Extra-oral and transoral approach may also be used. Although the procedure is technique sensitive, it is proposed with advantages of improved visualisation, magnifed feld of view, less trauma to tissues, less bleeding, better patient compliance, good reduction and decreased post-operative complications.

Frontal Sinus Fractures: Endoscopy in the management of frontal sinus fractures helps to avoid large incisions and its associated complications like alopecia, paraesthesia, scarring, nerve injury, etc. It helps in better visualisation of sinus wall fractures, nasofrontal duct and the posterior wall of sinus.


Endoscopy in nasal deformities: is a developing concept, and there has been an increase in its extensive usage in sinus endoscopic surgeries. The use of endoscope in correction of septal deformities like deviation, aids in better visualisation of the target site and reduced time of the procedure. The primary advantages are improved feld of view, reduced morbidity, decreased post-operative swelling and more accuracy in surgical procedure. Endoscopy in nasal corrections is very essential in cases that have gone for prior septal cartilage resection, reducing the need for repeated incisions or extent of dissection. Studies also suggest lesser post-operative symptoms in endoscopic-assisted nasal septal corrective surgeries [107].

#### **61.6 Conclusion**

Careful planning, eminent skills and excellent knowledge of the clinical anatomy are of utmost importance in carrying out secondary corrective procedures in treating residual deformities following trauma or oncological procedures. It is the skill of the surgeon to predict the functional and aesthetic outcome of the treatment so as to facilitate a proper treatment planning. It is also the role of the surgeon to educate the patient about the condition and options available for the correction, to provide the best possible outcome. It is recommended that surgeons use available imaging techniques (routine X-rays, CT scans, CBCT, etc.) in their treatment plans and also make best usage of the current trends in 3D models and visual planning software in treatment planning. The use of CAD/CAM-designed patient-specifc alloplastic (e.g. Medpore, PEEK) implants should be considered in surgical management. Treatment plan should often accommodate recommendations from other specialities that may be a part of the surgical team.

Both soft tissue and hard tissue deformities should be dealt together in a well-planned manner to provide the patient with an acceptable aesthetic outcome and functional rehabilitation. Likewise, mastication and prosthetic rehabilitation can be aided by dental and zygomatic implants. Most often correction of residual deformities may go together with reconstruction of the lost structures. It becomes essential to carry out the entire treatment phase in a well-planned manner to provide the patient with a fnal, socially and psychologically acceptable outcome with or without post-operative physical therapy. Surgeons are also recommended to be updated about endoscopy-assisted surgeries and transoral robotic surgeries to further enhance the quality of outcome of the treatment.

#### **References**

#### **Introduction**


#### **Grafts in Residual Deformities**


#### **Hard Tissue Deformities**


repositioning, for the correction of Crouzon's deformities. Plast Reconstr Surg. 1978;61:507–16.


#### **Post Oncological Deformities**


#### **Recent Advances: Endoscopy in Management of Residual Deformities**


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**Part XVII**

**Temporomandibular Joint Disorders**

## **Myofascial Pain Dysfunction Syndrome**

Mirza Farhatullah Baig and Yashoda Ashok

### **62.1 Introduction**

There is an accepted concept of triple complex involving both joints and intact dentition forming an integrated system which is carefully monitored by an arthrokinetic refex muscular activity to ensure a controlled and stable pattern of painless mandibular movement. A disturbance in the coordinated activity of this musculature arising from malocclusion often accentuated by psychological factors inducing neuromuscular tension forms the basis for majority of problems involving temporomandibular joint (TMJ) dysfunction.

There is a large pool of evidence that clearly shows that mind and body are not independently functioning entities but closely interrelated in all aspects of pain direction, detection and perception. TMJ disorders is an umbrella term referring to a classifcation of musculoskeletal disorders impacting the masticatory muscles and/or the TMJ and is usually subdivided into three main categories. Box 62.1 enumerates the three categories of musculoskeletal disorders, often clubbed as TMJ disorders.

#### **Box 62.1 Subcategories of TMJ Disorders (TMDs)**


M. F. Baig (\*)

Y. Ashok

It has always been a challenging job for the clinician to manage temporomandibular disorder (TMD) as it is a conundrum wrapped in enigma.

Management of TMD is controversial because science takes a back seat. We need scientifc studies especially randomised clinical trials to overcome this problem. Matching the diagnosis to the treatment is still the most problematic aspect of TMD practice. The solution lies in making an accurate diagnosis to match an appropriate method of treatment.

#### **62.2 Defnitions**

The defnitions for TMJ pain are not universally used. Three currently accepted defnitions of TMJ pain are:

	- (a) Aching in the muscles of mastication often associated with restricted jaw movements and popping sounds
	- (a) Temporomandibular joint sounds on movement
	- (b) Limited or jerky jaw movements
	- (c) Pain during jaw function
	- (d) Lock jaw on opening
	- (e) Gnashing of teeth (bruxism)
	- (f) Miscellaneous parafunction (tongue, lips or cheek biting)
	- (a) Chronic or intermittent pain of TMJ and of its associated musculature

**62**

Department of Oral and Maxillofacial Surgery, Saveetha Dental College, Chennai, India

Department of Oral and Maxillofacial Surgery, Meenakshi Ammal Dental College and Hospitals, Chennai, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1343

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_62

#### **62.2.1 Evolving Terminologies**

Over many years, functional disorders of the masticatory system have been referred by many terms contributing to the confusion regarding aetiologic mechanisms and manifestations in this area.

In 1934 James Costen [4], an otolaryngologist, described a set of symptoms focused around the ear and temporomandibular joint (TMJ) leading to the earliest nomenclature of Costen syndrome. Costen believed these symptoms were due to the backward displacement of condyle after overclosure of the bite. Auriculotemporal nerve is found behind the tympanic bone which prevents nerve compression. Hence this theory was rejected.

Schwartz [5] (1959) described myofascial pain dysfunction syndrome (MPDS) characterised by clicking, muscle tenderness, pain in the TMJ region and restricted mouth opening. Following this, much later the term TMJ disturbances became popular, and then, in 1959, Shore [6] introduced the term TMJ dysfunction syndrome. Later Ramfjord and Ash [7] brought forth the term functional TMJ disturbances. To establish a connect with the aetiology, terms such as occluso-mandibular disturbance and myoarthropathy of the TMJ [8] were introduced. When pain and associated muscle involvement became the focus, terminologies such as pain-dysfunction syndrome [9], myofascial pain-dysfunction syndrome [10] and TM pain-dysfunction syndrome [11] arose.

Currently it has been established that these terms attempt to describe conditions with symptoms not always isolated to the TMJ, and for the need of a broader, umbrella term to classify these conditions, some authors believe that the title craniomandibular disorders [12] should be used. Finally, the term which has gained large-scale acceptance was suggested by Bell [13]—"temporomandibular joint disorders".

#### **62.2.2 Current Defnition**

Myofascial pain dysfunction syndrome (MPDS) is a wellknown term that is used in many other branches of medical science [14–16]. But in the last few decades, this term has been employed to describe orofacial chronic pain [17–19] often abbreviated in the literature as MPDS.

Presently, myofascial pain can be defned as "a regional myogenous pain condition characterised by local areas of frm, hypersensitive bands of muscle tissue known as trigger points" [20] alternatively called myofascial trigger point pain. The presence of central excitatory effects is a defning characteristic of this myalgic disorder. The presence of referred pain is common, often resembling a tension-type headache.

#### **62.3 Etiopathogenesis and Proposed Mechanisms**

A number of mechanisms have been put forth to explain myofascial pain, even though currently a holistic understanding of aetiologies remains elusive (Fig. 62.1):


**Fig. 62.1** Pathogenesis of TMJ dysfunction


#### **62.4 Patient History and Clinical Characteristics**

The patient's main complaint is often directed towards the site of referred pain and rarely the exact source of pain (the trigger points). The clinician may accidentally direct treatment towards the secondary sites of pain resulting in failure to treat the actual cause of the pain, thereby leading to unsuccessful treatment. History taking must specifcally include incidences of repetitive muscle trauma, improper postural habits, presence of occlusal parafunction and mental and emotional stress.

On clinical examination, the patient will display decreased range and speed of mandibular movement which usually correlates to the location and intensity of trigger point pain. The pain is commonly described as a dull ache or pressure which can be throbbing and severe. The masticatory muscles are tender on palpation with identifable trigger points on palpation [25].

Trigger points are described as frm knots within muscles which are more tender on palpation than the surrounding muscle tissue. The pain that is generated is usually within and beyond the muscle and may occasionally elicit referred pain to a distant site and even an autonomic response.

Temporary inactivation can be tried through a trigger point anaesthetic injection, vapocoolant sprays, transcutaneous electrical nerve stimulation (TENS), etc. [26] which are used by certain practitioners to temporarily inactivate trigger points.

From a clinical standpoint, if the muscle is tender to palpation and none of the other masticatory muscle disorders better describe the patient's condition, the suggested diagnosis is myofascial pain.

#### **62.5 Examination**

	- Visual examination of the head and neck.
	- Palpation of the head and neck—This includes palpation of the individual masticatory muscles for tenderness (Figs. 62.2a, b and 62.3).
	- Listening to TMJ sounds and joint palpation (Fig. 62.4).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 62.2** (**a**, **b**) Palpation of temporalis

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 62.3** Palpation of masseter


#### **62.5.1 Imaging Techniques**

Pain in relation to the TM joint and masticatory muscles are among the commonest complaints of patients with TMD. MPDS is unique in that the contributing factors are neurogenic, psychogenic and musculoskeletal in nature. This greatly limits the role of conventional imaging modalities in clinching the diagnosis of MPDS.

OPG and CT are useful in imaging bony articular surfaces for erosions and changes in the joint spaces. MRI is excellent for imaging the disc, capsule and TM joint ligaments. However the usefulness of these imaging techniques appears restricted to ruling out other contributing factors to the patients' pain such as internal derangement and osteodegenerative disorders. These features may often overlap with myofascial pain, often adding to confusion in diagnosis.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 62.4** Palpation of temporomandibular joint

A thorough clinical examination is the most reliable way to arrive at a diagnosis of MPDS with imaging investigations assisting in ruling out other causative factors. Figures 62.5, 62.6 and 62.7 demonstrate some of the conventional methods of imaging the TM joint and associated structures with relevant fndings.

#### **62.6 Psychological Assessment**

It is mandatory to do psychological assessment or screening of the patient for history of anxiety, depression and painrelated disability.

#### **62.7 Pathophysiology of TMJ Pain**

**Pain** An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage [27] (*International Association for the Study of Pain 1979*).

*Infammatory Pain* Intra-articular tissue damage in association with disc displacement results in local TMJ pain. In addition, it can elicit refex spasm of masticatory muscles resulting in pain from regions other than TMJ.

*Arthrogenous Pain* The patient can point to the worst spot with one fnger in the TMJ region. The pain is relieved by giving auriculotemporal nerve (ATN) block.

*Myogenous Pain* Not relieved by block and diffuse in nature over the muscle.

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 62.6** CBCT shows erosions and craters in the head of the condyle and increased joint space

©Association of Oral and Maxillofacial Surgeons of India

#### **62.8 Role of Parafunctional Habits**

#### **62.8.1 Bruxism**

	- Attrition of teeth
	- Scalloping of the tongue
	- Cheek ridging—linea alba

A complete process of risk evaluation and assessment helps to highlight the problematic causative factors. These may include central and peripheral causes as shown in Table 62.1.

#### **62.9 Clinical Signs of MPDS**


#### **62.9.1 Clinical Test**

To diagnose clicking caused by disc displacement with reduction:


#### **62.10 Principles of Management**

#### **62.10.1 Role of Evidence-Based Management**

The varying manifestation of myofascial pain (MFP) can range from single muscle involvement to complex cases involving multiple sites of pain and numerous contributing

©Association of Oral and Maxillofacial Surgeons of India



factors. The challenge in management consists of educating patients about the lifestyle factors that contribute to MFP, the persistence of which tends to result in treatment failure. Studies by Fricton and Aronoff [29, 30] et al. indicate that patients with MFP visit multiple practitioners in their quest for relief and are often treated with multiple modalities in a disorganised manner without experiencing improvement other than on a temporary basis.

#### **62.10.2 Formulating a Comprehensive Problem List**

Patient must be encouraged to adopt therapeutic lifestyle changes such as diet modifcation, exercise, proper sleep habits, social support and coping mechanisms which may contribute to more holistic and long-lasting positive outcomes.

#### **62.10.3 Role of Interdisciplinary Management for the Complex Patient**

Patients exhibiting multiple and often overlapping risk factors are best approached via an interdisciplinary involvement that uses a team of specialists to address the varied nuances

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 62.9** (**a**) Restricted laterotrusive jaw movements—contralateral side (**b**) Unrestricted laterotrusive jaw movements—affected side

#### **Table 62.2** Causes of clicking

Causes of clicking


of the problem in an organised manner. In both simple and complex cases, the clinician needs to isolate the individual problem area and arrive at a customised solution best suited to the patient.

#### **62.10.4 The Role of Occlusal Splint: Termination of the Cycle of Habitual Pain**

Chronic pain is a learnt pattern that arises from repetition and is generated by the CNS. This habitual pattern must be arrested before attempting to treat MPDS. Treatment of MPDS is dependent on breaking the repetitive pattern generated by the central nervous system. Nociceptive responses are carried from peripheries into the central nervous system (CNS) through myelinated (type A-delta) or unmyelinated (type C) nerve fbres [31]. Dental malocclusion as a causative factor for MPDS has been found in literature since most treatment modalities hint at occlusal alteration one way or another. In a study by Laskin et al. [32], the authors remarked that many aspects of MPDS are yet to be explored; many have agreed that rapid improvement of symptoms is noticed with splint therapy. Splint therapy is an effective method of isolating occlusion as the causative factor as the interposition of a splint can immediately and dramatically break the pain pattern generated by the CNS. It is however necessary that splint therapy be initiated by skilled practitioners.

Soft splints are constructed of polyvinyl worn at night. It may act as a habit breaker.

The anterior bite plane or Lucia Jig is recommended for short-term use and is to be worn at night. Stabilisation splints help to disocclude the jaws, thereby restoring normal joint space with prolonged wear. These are also used to correct disc dislocations in internal derangement. The anterior repositioning splint allows the patient to close the mandible in a forward direction; however, this has not yielded successful results in many circumstances.

The gnathological splint was designed based on Roth's philosophy of correction of centric relation-centric occlusion discrepancies. It is a permissive type of hard splint made of heat cure clear acrylic fabricated using a semi-adjustable articulator (SAM 3, AD2, PANADENT articulators). It is usually worn full time in maxillary or mandibular arch. The splint is designed on the concepts of gnathology to correct the centric relation-centric occlusion (CR-CO) discrepancies, which are a sequence of progressive disc derangements.

A few important factors to be considered prior to splint fabrication include diagnosis and institution of therapy by skilled clinicians, and alteration of occlusion results in clicking sound in the TMJ. (**a**) Patient in closed mouth position, with anterior disc displacement (shown by TMJ superimposition) and (**b**) Condyle translating over the displaced disc (TMJ superimposition), to produce clicking sound

©Association of Oral and Maxillofacial Surgeons of India

changes in masticatory behaviour which in turn alters neuromuscular activity and learnt patterns of pain generation. Regular follow-up is essential after splint usage. This helps to identify any complications as a result of splint therapy which might mandate stoppage of splint therapy altogether [33, 34]. The specifc type of splint and duration of treatment must be carefully titrated for individual patients. Overuse of the right splint can also result in worsening of the condition by creating open bites, intrusion of teeth and loss of occlusal contact and worsening of MPDS symptoms [35–37].

#### **62.10.5 Occlusal Adjustments**

Wang et al. advocated elimination of premature contacts using occlusal adjustment as one of the most crucial methods for breaking the neuromuscular cycle in MPDS [38]. A thorough occlusal analysis has consistently been an instrumental diagnostic criterion to resolve MPDS symptoms.

#### **62.11 Modalities of Management of MPDS**

Because of the prolonged and occasionally varied treatment phases in the management of myofascial pain, the healthcare provider must develop a long-term association with the patient and direct the goals towards fostering a positive attitude towards therapy and commitment to long-term change [39, 40].

#### **62.11.1 Muscle Exercises**

Muscle exercises are the most effective for muscle rehabilitation. Active muscle stretching combined with passive exercises diminishes the sensitivity of trigger points. Postural exercises reduce trigger point reactivation, while strengthening exercises serve to enhance circulation and suppleness of the muscles. Determination of the muscular range of motion is the preliminary requirement prior to prescribing physiotherapy.

Postural exercises function to teach the patient to adopt a more neutral and relaxed body position, thereby ameliorating fatigue from undue stress on a set of muscles. Interincisal mouth opening is an effective indicator of muscle range of motion, and limited mouth opening is indicative of tender points in the masticatory muscles. Adverse postures such as jaw thrust and forward head position must also be discouraged.

Correctional exercises include:


#### **62.11.2 Muscle Treatments**

*There are various techniques for muscle stimulation.*

*Non-invasive methods of trigger point (TrPs) inactivation include*


#### *Relaxation measures include*


#### *Electrical current stimulation through*


*Methods of chemical and mechanical alteration of TrPs are achieved by*:


*Spray and stretch technique*: Local muscle vapocoolant spray application alongside passive stretching renders instant pain relief [21, 42]. Failure of this technique has been attributed to:


#### **62.11.3 Trigger Point (TrP) Injections**

Pain reduction, improvement in range of motion, better exercise tolerance and generalised enhancement of circulation in muscles are some of the positive effects of trigger point injections as documented by Cifala et al. [43] and Jaeger and colleagues [44].

Trigger point injections act by physical disruption of the trigger point from needle entry, and the pain relief may be seen to last from the anaesthetic duration to several months. Saline injections and "dry needling" have also been reported with varying degrees of success. Dry needling, frequently known as myofascial trigger point dry needling, is an alternative medicine practice comparable to acupuncture. It is carried out by physical therapists where permissible by state laws. The use of a combination of sub-anaesthetic doses of local anaesthetic agents has also been found to be successful. The results of a double-blind controlled trial by Simons et al. [45] suggested 3% chloroprocaine and 5% procaine (without vasoconstrictors) to be effective.

Corticosteroid in combination with a local anaesthetic administered as a local intramuscular injection was frst practised in the early 1950s. Though there haven't been randomised trials to prove the effcacy of the same, Gray and colleagues suggested that locally delivered corticosteroids mitigate pain and improve function in patients with MPDS [46].

#### **62.11.4 Trigger Points**

These are areas of taut, infamed muscle bands that elicit pain on palpation. Pain of this origin is usually referred to other sites in the local region. Figure 62.11a–e demonstrates the various muscles of the head and neck and the related trigger points elicited in MPDS.

#### **62.11.5 Bite Adjustment**

Despite many MPDS cases being treated from an occlusionrelated standpoint, literature has shown dental occlusion or partial and total edentulism to be weakly correlated as causative or maintenance factors of TMPDS [47, 48].

Therapies ranging from occlusal adjustments on natural teeth to extensive prosthetic dental rehabilitation have been reported. Other treatments include oral appliances and orthodontics. Marbach [49] et al. demonstrated that missing teeth, malocclusion and night-time bruxism in control group patients did not correlate with facial pain and vice versa.

**62.12 Intraoral Appliance Therapy** *(Refer to suggested reading at the end of the chapter)*

Stabilisation appliances are well accepted, but the clinician must ensure that they are not ill-ftting, bulky, etc., so it is imperative to adjust them for patient comfort and better compliance. Regular reviews and inspection for soft tissue ulceration, dental pain, oral malodours, speech impairment, caries, tooth mobility and occlusal alterations must be carried out.

Splints: Box 62.2 enumerates the broad classifcation of splints conventionally used in the management of MPDS.

©Association of Oral and Maxillofacial Surgeons of India

Soft Bite Guard: Splint is constructed of polyvinyl worn at night. It may act as a habit breaker and also serves to protect the occlusal surfaces of the teeth (Fig. 62.12).

The Anterior Bite Plane or Lucia Jig (Fig. 62.13): For short-term use to be worn at night.

Stabilisation Splint: It is a hard splint made of acrylic for the restoration of occlusion (Fig. 62.14). It minimises abnormal muscle activity and restores neuromuscular balance.

Gnathological Splint: A specialised splint based on Roth's philosophy: To correct centric occlusal-centric relation discrepancies (Fig. 62.15a, b).

#### **62.12.1 Pharmacotherapy**

Multiple different pharmacologic therapies have found application in MPDS.

#### **62.12.1.1 Non-steroidal Anti-infammatory Drugs (NSAIDs)**

In the case of TMPDS, few controlled trials exist that indicate daily use of NSAIDs offers little beneft when compared

#### **Box 62.2 Splints Used in the Management of MPDS (Refer to suggested reading at the end of the chapter)**

Types of splint:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 62.12** Soft splint

to the well-known occurrence of side effects as reported by Dionne et al. [50]. Singer and colleagues concluded that a 4-week trial of ibuprofen 1500 mg per day was no more effective than a placebo [51]. Patients report short-term relief with high doses of NSAIDs; however, long-term therapy with NSAIDs is not encouraged.

#### **62.12.1.2 Opioids and Narcotic Analgesics**

With the use of opioid and narcotic analgesics comes the problems of physical dependence, addiction and drug tolerance. There is a lack of controlled studies in literature to guide the clinician regarding the same which restricts the use of these drugs specifcally to recalcitrant cases. Patient selection is critical when instituting opioid therapy, and success of therapy is usually measured by reports of reduction in pain intensity, return to quality of life and achievement of a stable dose.

Oral opioids are, namely, sustained release morphine, meperidine and butalbital in combination with aspirin and caffeine. Transdermal fentanyl is effective in some cases.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 62.13** Anterior bite plane or Lucia Jig

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 62.14** Stabilisation splints (hard split)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 62.15** (**a**) Gnathological splint (intraoral) (**b**) Gnathological splint (in vitro)

#### **62.12.1.3 Antidepressants**

Antidepressant drugs are frequently used in the management of a number of pain conditions, including MPDS. Studies indicate that these drugs behave independent to their role as antidepressants since they are effective at low doses (on average 23.6 mg for pain relief as opposed to a mean of 129 mg for depression) [52].

Amitriptyline and imipramine have been widely researched for their antidepressant and pain control properties. Dosage is initiated at 10 mg during bedtime and, if needed, is raised in 10 mg increments up to 30–40 mg. Analgesic effects are noted to occur within a few days. Side effects include sedation, constipation and dry mouth. TMPDS case reports have shown anecdotal evidence suggestive of agitation arising from selective serotonin reuptake inhibitors. Citalopram, a Selective Serotonin Reuptake Inhibitor (SSRI), had comparable effects to a placebo in the treatment of fbromyalgia [53]. Earlier sources of literature have also highlighted the effcacy of monoamine oxidase inhibitor drugs (phenelzine, tranylcypromine) in the treatment of orofacial pain conditions [54].

#### **62.12.1.4 Muscle Relaxants**

In the short term, diazepam and related muscle relaxants bring about relief from painful muscle spasms but are effective only for a short-term basis.

Benzodiazepines are associated with development of tolerance when used for a long period of time among other side effects. Varying degrees of relief have been reported with relatively low (diazepam, 5 mg bid; clonazepam, 0.5 mg bid or tid) doses, and usually an increase in dosage is not mandated.

#### **62.12.2 Supportive Therapy**

#### **62.12.2.1 Ultrasound and Electrogalvanic Stimulation**

Painful trigger points have been demonstrated to be managed effectively with therapeutic modalities such as ultrasound application and electrogalvanic stimulation (EG) [55]. Ultrasound causes localised muscle relaxation by producing heat deep within the fbres corresponding to the trigger points [56]. Low-voltage EG stimulation is used to stimulate muscles in a phased and rhythmic manner. This results in muscle relaxation and reduced muscle hyperactivity [57, 58]. These techniques are generally considered conservative and are extremely useful in mild to moderate cases of MPDS.

Box 62.3 outlines the prognosis and some of the important pearls to be borne in mind by the clinician attempting to treat MPDS.

#### **Box 62.3 Clinical Pearls for Successful Outcomes and Prognosis of MPDS**

Successful outcomes and prognosis of MPDS are dependent on the following factors:


#### **62.13 Treatment Summary**

The management of MPDS can be summarised as follows (Table 62.3). (Refer also to Chap. 63 - Internal Derangements of the Temporomandibular Joint)

#### **62.14 Recent Advances**

Newer management methods that have emerged in the recent years for treatment of MPDS include botulinum toxin injections as well as cold and soft laser therapy.

#### **62.14.1 Botulinum Toxin Injections**

Botulinum toxin injection enhances vascularity by augmenting the blood fow to the affected muscles and releases the taut muscle fbres caused by abnormally contracting muscles [59]. It has also been reported to increase endogenous endorphin secretion by way of needle insertion into trigger points [60, 61]. However, studies reveal that 3–10% of patients develop neutralising antibodies with long-term adverse effects that include muscular atrophy [62].

The injection solution is prepared by dissolving 100 IU of botulinum toxin into 1.0 mL of sterile saline solution (0.9%) at room temperature to be done immediately before injection. An insulin syringe with a hypodermic needle may be used for administering the injection. Small increments of this **Table 62.3** Summary of MPDS stages and authors' recommendation for management


solution may be injected into trigger points in different muscles. (refer Chap. 33 for more details)

#### **62.14.2 Cold and Soft Lasers**

Cold laser therapy or low-level laser therapy (LLLT) has been shown to play a substantial role in the treatment of generalised musculofascial disorders and facial pain relief [63– 66]. After a thorough clinical examination of the patient that must reveal clearly the affected muscles, a treatment cycle is formulated which usually consists of low-level laser application like Ga-Al-As (Endolaser) of wavelength 780 mm for 4–6 weeks.

Theories put forth to explain pain reduction via low-level laser therapy include hyperpolarisation of neuronal cell membranes and resultant elevation of pain threshold alongside an increase in the secretion of morphine-like substances such as encephalin and endorphin which have an analgesic and anti-infammatory effect [11].

Since trigger points are known to be of infammatory nature [6], it can be concluded that laser application alleviates oedema, infammation and pain by inhibiting infammatory components such as prostaglandin (PGE2), prostacyclins, histamine and kinin.

#### **62.15 Summary and Conclusion**

It would be appropriate to conclude that successful outcomes and prognosis of MPDS are dependent on accurate diagnosis, appropriate case selection and above all an interdisciplinary involvement that uses a team of specialists to address the various nuances of the problems in an organised manner.

The clinician needs to isolate the individual problem area and arrive at a customised solution best suited for the patient.

The following salient points must be borne in mind by the reader on completion of the chapter on MPDS as shown in Box 62.4.

#### **Box 62.4 Summary of Important Points**


#### **62.16 Case Scenarios**

#### **Case 1:** (Fig. 62.16a–c)

A 29-year-old female patient complained of pain in the head and jaw for the past 2 years and underwent medical treatment for the same with little relief. On examination, muscles of mastication were sore and there was diffculty in manipulation of the jaw, and the patient showed a deep bite (Fig. 62.16a). CBCT showed increased joint space and MRI showed normal imaging. Having diagnosed with MPDS, the patient was advised gnathological splint (Fig. 62.16b) for full-time wear. The symptoms improved over 6–8 months. Post splint therapy, the bite was considerably opened (Fig. 62.16c), relieving pressure on the joint structures, and the patient was forwarded for orthodontic settling.

#### **Case 2:** (Fig. 62.17a–c)

A 48-year-old female patient complained of pain in the head and neck for the past 1 year. All the symptoms started with dental procedures which lasted long. On examination there was severe muscle spasm with tenderness in muscles of mastication and diffculty in opening mouth due to muscle spasm, and deviation on mouth opening was also seen. Intraorally, she had a deep anterior bite which was almost closed in relation to 11, 21, 31, 41 (Fig. 62.17a). CBCT and MRI showed normal imaging, and hence she was advised a gnathological splint (Fig. 62.17b) for her myofascial pain and to open the bite. The symptoms improved over 3–5 months of full-time wear, the bite was signifcantly opened and the patient was referred for orthodontic settling of the bite.

#### **Case 3:** (Fig. 62.18a–c)

A 21-year-old female patient who was a dental student reported with clicking sounds and pain on both sides of the lower jaw and severe teeth grinding at night for the past 6

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 62.16** (**a**) Anterior deep bite with spacing in the lower anteriors. (**b**) Gnathological splint in place. (**c**) Post splint therapy correction of deep bite prior to orthodontic settling

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 62.18** (**a**) Palpation of tender points on the temporalis and masseter muscles. (**b**) The Lucia Jig. (**c**) Patient wearing the Lucia

Jig

**Fig. 62.17** (**a**) Pretreatment occlusion showing anterior deep bite. (**b**) Gnathological splint in place. (**c**) Post splint therapy

©Association of Oral and Maxillofacial Surgeons of India

months. The patient was clinically examined, severe tenderness was elicited on palpating the masseters and temporalis bilaterally (Fig. 62.18a), and intraoral signs of enamel wear from attrition were apparent. Imaging of the TMJ via MRI showed a normal study. She was advised to wear a Lucia Jig (Fig. 62.18b, c) for 3 months in order to disocclude the posterior teeth. In addition, she was prescribed amitriptyline (10 mg) once a day at night which she took for the same period. On follow-up after 3 months, she had complete relief from the pain and reported complete cessation of the parafunctional habit.

**Acknowledgement** The authors would like to acknowledge the invaluable contributions of a few who helped make this chapter a rewarding endeavour. We would like to thank Dr Elavenil P for her tireless efforts towards shaping important nuances of this chapter for the textbook. Dr Faisal Tajir and Dr Arvind Muhthukrishnan are sincerely appreciated for their timely contribution of clinical photographs and case scenarios included herein. The authors would like to extend heartfelt thanks to Dr Vidya Devi for the illustrations in this chapter.

**Disclosure** Authors have no fnancial conficts to disclose.

#### **References**


ment of myofascial type painful temporomandibular diseases. Oral Surg Oral Med Oral Pathol Oral Radiol. 2013;116(3):377–83.


#### **Suggested reading**

Basics of Occlusal Splint Therapy (Internet). Dentistry Today 2002 (Cited October 21, 2020). Available at https://www.dentistrytoday. com/prosthodontics/prosthetics/1716.

**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Internal Derangements of the Temporomandibular Joint**

Gary Warburton

#### **63.1 Introduction**

The term "internal derangement" has been used for more than a century in surgical and orthopedic literature to describe conditions that interfere with normal joint function [1, 2]. In the knee, the term internal derangement is broadly used to describe a torn, ruptured, or deranged meniscus of the knee, a partial or complete cruciate rupture, with or without injury to the capsular ligament of the knee, resulting in ongoing or intermittent signs and symptoms such as pain, instability, or abnormal mobility. Alterations in the disc, condyle-fossa relationships in the temporomandibular joint (TMJ) were suspected as early as 1887 by Sir Astley Cooper and published by Annandale in the Lancet "on displacement of the inter-articular cartilage of the lower jaw, and its treatment by operation" [3]. The term internal derangement was adopted and used to describe disturbances between the articulating components of the TMJ, alluding to the damage to the internal structures and dysfunction of the joint associated with changes in the position of the disc [4, 5].

In the TMJ literature, the term has evolved to be synonymous with disc displacement. In the 1970s and 1980s, TMJ internal derangement was perceived as a mechanical problem and resulted in attempts to reposition or replace the disc. In 1979, McCarty and Farrar stressed on the relevance of disc displacement as a major disorder of the TMJ [5]. It was believed that a displaced or abnormal disc was a progressive problem that led to degenerative joint disease and as a result importance was given to repositioning the displaced disc. Conservative therapy was done by mandibular manipulations and oral appliances, and surgical repositioning was per-

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_63) contains supplementary material, which is available to authorized users.

G. Warburton (\*)

formed for patients who had persistent symptoms. A commonly performed surgical procedure was repositioning of the disc, and if the disc was perforated or beyond repair, even discectomy was performed. Various materials and tissues were used for disc replacement (cartilage, dermis, muscle fascia, fat, silastic, and Proplast-Tefon). However, the use of Proplast-Tefon resulted in severe destruction of the articular surfaces due to foreign body giant cell reactions [6–8].

Over the past few decades, there has been a conceptual shift from internal derangement and disc displacement being a primary diagnosis toward our current understanding that disc displacement/internal derangement is an endpoint and a manifestation of a process in which there is damage to articular tissues and biomechanical failure from a specifc cause that must be identifed if treatment is to be successful.

Clinical and basic science research has led us to the conclusion that internal derangement represents a variety of stages of biomechanical failure of the joint tissues, resulting from different causes.Wilkes staging system (Table 63.1) categorizes the extent of joint damage in internal derangement without being specifc for the underlying cause that is responsible for the failure of the joint tissues. With this limitation in mind, Wilkes classifcation [9] is still useful today in communicating severity and guiding treatment.

The realization in the 1990s that arthroplasty with disc repositioning or discectomy often leads to degenerative joint disease and fbrosis, coupled with the fact that the disc repositioning was not reliably maintained, caused a major change in surgical management. Arthroscopic surgery of the TMJ was shown to be an effective alternative to arthroplasty. Arthroscopy was a reliable procedure to reduce the pain and to improve the maximal incisal opening without causing a change in position of the disc [10–15]. The role of disc displacement and disc position in symptomatic patients has been further questioned due to the fact that MRI studies have documented disc displacement in 32–38% of asymptomatic patients and volunteers [16, 17]. We now know that the abnormally positioned disc is not the primary cause on pain and dysfunction for many

**63**

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1361

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_63

Department of Oral and Maxillofacial Surgery, University of Maryland School of Dentistry, Baltimore, MD, USA e-mail: gwarburton@umaryland.edu



patients as the majority of patients with displaced discs are asymptomatic through the process of adaptation.

Arthrocentesis was subsequently introduced as another effective yet minimally invasive means of treating patients with symptomatic internal derangement [18–22]. Arthroscopy and arthrocentesis allowed sampling synovial fuid and has been of tremendous value in our understanding of the biochemical mediators and cytokines responsible for infammation, cartilage degeneration, and destruction of joint tissue leading to internal derangement [23–26].

Diagnostic criteria for temporomandibular disorders (TMD) for research and clinical purposes were recently updated in 2014 [27] and include internal derangement or disc displacement which is presented as:


Normal disc position, displacement with reduction, and displacement without reduction are depicted in Fig. 63.1.

### **63.2 Epidemiology**

Internal derangement of the TMJ is a relatively common problem. Farrar estimated that up to 25% of the population has TMJ internal derangement [28]. Epidemiologic studies have shown that TMJ clicking is detectable in up to 31% of the population, and crepitus is detectable in up to 40% of the population on auscultation, with a higher prevalence among women.

MRI studies have documented disc displacement in 32–38% of *asymptomatic* patients and volunteers [15, 16]. The mean age for TMJ disorders is 34 with 90% of patients falling within 15–45 years of age range. Agerberg et al. studied 637 people aged 18–65 and found an incidence of 21% clicking in men and 28% in women, while crepitus was noted in 26% of men and 40% of women [29]. Disc displacement occurs most commonly in the anterior or anteromedial direction, which is the most common direction of displacement followed by lateral and rarely posterior displacement accounting for only 0.7% of displacements [30].

#### **63.3 Etiology**

Internal derangement is an endpoint and a manifestation of a process in which there is damage to articular tissues and biomechanical failure from a specifc cause that must be identifed if treatment is to be successful. The broad etiologic categories resulting in internal derangement are:


An alternative framework regarding etiology is:


The majority of patients fall into the normal joint subjected to overload etiologic category and in particular due to parafunctional habits of clenching or bruxism during the day or at night.

Historically occlusion has been considered a primary etiologic factor, but this has now been refuted in current evidence-based literature [31, 32].

#### **63.4 Anatomy and Function Relevant to Internal Derangement**

The TMJ is a hinging and sliding synovial joint (ginglymoarthrodial joint) and forms the articulation between the mandibular condyle and the temporal bone. The articular surfaces

Anterior disc displacement

with reduction

Normal disc position

Anterior disc displacement without reduction

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 63.1** Normal and displaced disc positions, with and without reduction (modifed with the permission of Dr. Robert Talley)

are covered with fbrocartilage, while most other synovial joints are composed of hyaline cartilage. Fibrocartilage is composed of fbrochondrocytes, fbroblast-like cells, type I collagen, and proteoglycans. Fibrocartilage is less susceptible to degeneration and also has a greater repair capacity compared to hyaline cartilage [33]. The articular disc or meniscus that is interposed between the mandibular condyle and articular eminence of the temporal bone is also a fbrocartilaginous structure in the shape of a biconcave elliptical disc. It has a thicker posterior and anterior band with a thinner intermediate zone in between (Fig. 63.2). From a lateral viewpoint in the closed mouth position when the condyle is seated in the glenoid fossa, the posterior band is normally positioned at the 12 o'clock position from a point in the center of the condyle. As the condyle rotates and translates forward beneath the disc during mouth opening, the disc comes to lie above the condyle (this has been termed "roofng"). The disc itself is an avascular structure and that has no innervation. The metabolic and nutritional requirements of the avascular disc are provided by the surrounding synovial fuid through a process known as weeping lubrication (whereby a small amount of synovial fuid is forced into and out of the disc during the compressive forces generated by joint function and loading of the disc). The disc is anchored to the medial and lateral poles of the condyle by the collateral (discal) ligaments (Fig. 63.3).

Figure 63.4 shows the attachments of the disc in a sagittal view. The posterior attachment of the disc is the retrodiscal

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 63.3** Coronal view of the medial and lateral collateral (discal) ligaments

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 63.4** Attachments of the disc in a sagittal view (modifed with the permission of Dr. Robert Talley)

tissue. The retrodiscal tissue is a bilaminar structure with a superior lamina, inferior lamina, and intervening loose connective tissue that is very vascular and well-innervated. The retrodiscal attachment connects the disc to the tympanic plate of the temporal bone by the superior lamina, which is composed of connective tissue and elastic fbers. These elastic fbers condense to form a prominence recognized arthroscopically as the posterior oblique protuberance/band. The inferior lamina is composed of collagen fbers and inserts into the condylar neck. The disc and retrodiscal tissue together divide the TMJ into upper and lower joint spaces which are flled with synovial fuid. The anterior attachment of the disc is to the temporal bone, the anterior condylar neck, and the upper head of the lateral pterygoid muscle, while the medial and lateral attachments are to the capsular ligaments as well as the collateral ligaments. All the joint surfaces are covered with synovial lining except the disc itself, glenoid fossa, articular eminence, and condylar head.

It is the collateral (discal) ligaments along with the superior and inferior lamina of the retrodiscal tissue that are disrupted and elongated when the disc is displaced anteriorly in internal derangement.

The glenoid fossa of the temporal bone lies immediately beneath the middle cranial fossa (Fig. 63.5a, b). From both arthroscopic and open surgical standpoints, one must recognize that the bony roof of the fossa is extremely thin. An autopsy study revealed that the glenoid fossa was only 0.2– 1.5 mm thick in normal joints and 0.5–2.0 mm thick in joints with disc displacement [34]. Care must be taken not to perforate the thin roof of the fossa during arthroscopic and open TMJ surgical procedures.

The TMJ is innervated by the trigeminal nerve, predominantly through the auriculotemporal branch of the mandibular division which passes behind the condylar neck and penetrates the capsule to enter the joint. However, some innervation also comes from the deep temporal and masseteric branches.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 63.5** (**a**) Sagittal section through TMJ and glenoid fossa. (**b**) Cadaveric specimen viewed from the middle cranial fossa (brain removed) with an arthroscope in the left TMJ. Both demonstrate the thin roof of the glenoid fossa

#### **63.5 Clinical Features and Diagnosis**

The most common presenting complaints in patients with TMJ internal derangement include:

Pain Joint noises (click or crepitation) Loss of function Occasionally a change in occlusion

The loss of function may be due to limited mouth opening (closed lock in anterior disc displacement without reduction), a mechanically obstructive click, or dietary compromise secondary to pain.

#### **63.5.1 Patient History**

A good clinical history is essential for accurate diagnosis of any TMJ disorder including internal derangement. Questions including onset and evolution of the problem may reveal a classical story of a clicking or "popping" joint, indicating a disc displacement with reduction, or a story in which a patient with a history of a clicking joint notices that the click suddenly disappears and at the same time develops limited mouth opening and pain indicative of progression to disc displacement without reduction. Questions regarding initiating factors are helpful in identifying the underlying etiology (trauma or parafunction). Patient reports of pain increasing with stress or pain present on waking from sleep are strongly suggestive of parafunctional habits.

The answers to these pain questions may suggest pain originating from the joint when the pain is localized over the preauricular area, compared to muscular pain when it is more Other questions should include details of prior treatment attempts and specifc questions regarding pain:

Location Radiation Severity Timing (intermittent or constant) Duration and frequency of episodes Exacerbating factors Relieving factors Associated symptoms (headache, tinnitus, etc.)

widespread, a critical differentiation in determining appropriate management. Problems with other joints such as pain or laxity may suggest systemic arthritis or even conditions such as Ehlers-Danlos syndrome.

#### **63.5.2 Patient Examination** (Fig. 63.6a–c)

Should include examination of the muscles of mastication, TMJ, range of mandibular motion, and intraoral examination to evaluate occlusion and signs of parafunction (buccal mucosal ridging at the level of the occlusal plane, scalloping of the lateral border of the tongue, tooth wear, and fractured teeth or restorations).

When examining each pair of muscles, one should evaluate for tenderness, trigger points, muscle mass, and tone. If the patient reports pain on palpation (indicating myalgia), it is helpful to determine if the pain is localized to the point of palpation (local myalgia), spreading beyond the point of palpation but within the muscle boundary (myofascial pain), or radiates outside the muscle boundary (myofascial pain with referral).

**Fig. 63.6** (**a**–**c**) Examination of muscles, joint, and range of motion

**Fig. 63.7** Anterior disc displacement and retrodiscitis (as seen in the inset arthroscopic image) with a positive direct pressure loading test of the right TMJ = biting on tongue blades between left canines loads the right TMJ, and pain is reported in the right TMJ

©Association of Oral and Maxillofacial Surgeons of India

When examining the joint, one should evaluate for tenderness, swelling, range of motion (hinge and translation), symmetry of motion or deviations, subluxation/dislocation, clicks, and crepitation. Joint noises may be audible or palpable, but some may only be detected by auscultation. Timing of any opening click provides clinical information on the extent of disc displacement before reduction. A very early click on condylar translation suggests minimal anterior disc displacement before reduction, while a late click suggests greater anterior displacement of the disc. If the disc is anteriorly displaced, there may be signifcant retrodiscitis due to the condyle functioning on the retrodiscal tissue rather than the disc itself (Fig. 63.7). If the patient is asked to bite on two wooden tongue blades between the canine teeth and they report pain localized to the contralateral TMJ that is now being loaded, this is pathognomonic for retrodiscitis and is known as a positive direct pressure loading test. Crepitations often indicate perforation, usually in the retrodiscal tissues, and may occur due to long-term function on the retrodiscal tissue or trauma.

#### **63.5.3 Radiographic Evaluation**

While plain radiographs and CT scans are useful for evaluating bony changes, MRI scans are best suited for evaluating disc position and displacement and have a diagnostic accuracy of at least 90% [35]. MRI should be ordered with both T1 and T2 images in the open and closed mouth positions (Fig. 63.8a–c); often additional imaging sequences are helpful such as fat suppressed or STIR sequences which help to show edema in tissues that contain fat. This can be helpful in evaluating edema in the cancellous bone of the condylar head. Using MRI, one can assess the bone of the condyle, fossa, and eminence (looking for sclerosis, erosions, fattening, osteophytes, and breaks in cortical continuity), the disc

**T1 Closed T1 Open T2**

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 63.8** (**a**–**c**) MRI scan—T1 and T2 images in closed and open mouth positions. (**a**) Normal disc position. (**b**) Anterior disc displacement with reduction. (**c**) Anterior disc displacement without reduction and superior joint space effusion

(looking at its position, density, shape, size, and continuity in cases of perforation), effusions which are easily seen on T2 sequences, and fnally for collapse of the joint space. The sagittal closed and open mouth images determine if the disc is displaced and whether or not it reduces on opening.

#### **63.5.4 Serology**

Is helpful in the diagnosis of primary infammatory arthritis (Table 63.2). Rheumatoid factors (RFs) occur in 60–80% of patients with rheumatoid arthritis (RA) [36]. While they are sensitive, their diagnostic utility is limited by their relatively poor specifcity, since they are also found in 5–10% of healthy individuals, 20–30% of people with SLE, virtually all patients with mixed cryoglobulinemia (usually caused by hepatitis C virus infections), and those with many other infammatory conditions. Higher titers of RFs (at least three times the upper limit of normal) have somewhat greater specifcity for RA. The prevalence of RF positivity in healthy individuals rises with age. More recently, other antibody markers have been utilized. Anti-cyclic citrullinated peptide (anti-CCP) antibodies have a similar sensitivity to RF for RA but have a much higher specifcity (95–98%). Anti-CCP antibodies are also present early in the disease, and their presence often correlates with more severe forms of RA, making them better prognostic indicators [37]. HLA-B27 is associated with seronegative spondyloarthropathies, psoriatic and reactive arthritis [38].

**Table 63.2** Serology in primary infammatory arthritis

Serology • Rheumatoid factor → Rheumatoid arthritis

• HLA B-27 → Reactive arthritis, ankylosing spondylitis, juvenile reactive arthritis


#### **63.5.5 Diagnostic Local Anesthetic Block**

In complex cases where history and examination fail to clearly confrm pain originating from the joint itself, or in cases that have undergone previous surgeries on the TMJ, or in chronic pain patients, an auriculotemporal nerve block and injection of local anesthetic into the superior joint space is very helpful and can demonstrate the amount of pain originating from the joint. The author uses 3% mepivacaine injected using a dental syringe (Fig. 63.9a–c). With the patient in occlusion, the needle is inserted and advanced to contact the posterior condylar neck where half the carpule is injected as an auriculotemporal nerve block. The patient then opens their mouth, and the needle is advanced superiorly to contact the posterior slope of the articular eminence, and the remaining anesthetic is deposited into the superior joint space. The patients pain score before is compared to the pain score 10–15 min after injection. Any portion of pain that has resolved is most likely originating from the joint. This is helpful in determining if surgery is indicated and also in providing realistic postoperative pain expectations for the surgical patient.

#### **63.6 Treatment of Internal Derangement**

Treatment for internal derangement can be divided into nonsurgical and surgical options, but the general treatment goals are the same:

Decrease joint overload Decrease pain Reduce infammation Improvement in the range of motion Restore function Causative factors to be identifed and controlled

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 63.9** (**a**–**c**) Diagnostic auriculotemporal nerve block and TMJ injection

Clinical research [39–41] into the natural progression of TMJ internal derangement has shown:


#### **63.6.1 Nonsurgical Treatment**

#### *Nonsurgical options include*:

Occasionally, psychology referral and counselling are indicated in certain patients.

Patient education is of great value. A simple explanation of the mechanics causing a clicking joint with internal derangement with the information that around 30% of the population have internal derangement can be very reassuring and put a patient's mind at ease. Furthermore, educating the patient in habit awareness to avoid daytime clenching is a key element in the long-term success of any nonsurgical or surgical treatment (Table 63.3).

Orthotic devices or occlusal appliances may help to reduce nighttime parafunctional habits. However, our understanding of orthotic devices has changed signifcantly over time. In the late 1930s and 1940s, temporomandibular joint disorders (TMD) used to be seen as problems related to occlusal or skeletal disharmony. Costen was an otolaryngol-



• Psychiatrist

ogist who in 1934 frst suggested the link between occlusion, TMJ disorders, and ear symptoms based on his observations in 11 patients [42]. This evolved into orthotics and occlusal therapies being used for the treatment of TMJ disorders in the 1940s and 1950s. However, a signifcant paradigm shift has occurred as the classic dental and skeletal etiologic theories have been challenged and refuted by studies conducted around the world, and a biopsychosocial medical model of orthopedics, pain phenomenology, and behavioral factors has gradually replaced them. As a result, the conceptual basis for occlusal appliances/orthotic use has signifcantly changed over the years. Occlusal appliances/orthotics were initially conceived and used based on these old dental and skeletal etiologies and were thought to produce occlusal disengagement, relax jaw musculature, restore vertical dimension of occlusion, unload the joint(s), or reposition the condyle and or disc. Even today, these are often described as deprogrammers or jaw-repositioning devices that can establish ideal craniomandibular relationships wile relieving pain and restoring function. Until the 1960s, there were no wellcontrolled, well-designed, systematic studies evaluating the treatment of TMD. Instead, there were a number of anecdotal reports claiming success with various mechano-dental treatments, including various designs of oral appliance or orthotic [43, 44]. As the evidence-based literature has evolved, these reports have been refuted. Lundh [45] divided patients with symptomatic TMJ disc displacement into two treatment groups: one group with no treatment and one group with an occlusal appliance/orthotic and compared outcomes. After 12 months, pain had resolved in around 33% of patients in both groups. 40% of patients reported increased pain in the occlusal appliance/orthotic group compared to 16% in the no treatment group. Truelove [46] evaluated 200 patients with anterior disc displacement with reduction, arthralgia, and myalgia who were randomly assigned into three treatment groups: group 1 had basic nonsurgical treatment (education, self-care, hot/cold packs, and passive stretching), group 2 had hard fat plane occlusal appliance/orthotic, and group 3 had soft splint. Outcomes were evaluated after 3 and 12 months, and there were no signifcant differences in success among the three groups. Greene [47] and Laskin [48] studied the placebo effect using mock/sham occlusal appliances and sham occlusal adjustments. They found that nonoccluding appliances/orthotics helped over 40% of patients and mock/sham occlusal adjustments helped almost twothirds of patients. Furthermore, the use of occlusal appliances/orthotics may increase the parafunctional habit in some resulting in a patient complaining of increased pain and/or stiffness after use. In addition, partial coverage devices may result in occlusal changes if used for more than a few months due to eruption of teeth. Therefore, our perception of occlusal appliances/orthotics must take into consideration the current evidence-based literature.

In review of evidence-based literature on occlusal appliance/orthotics [45–47, 49, 50], we can conclude:


In Klasser's review [50] of occlusal appliances/orthotics, he concludes that rather than trying to establish new horizontal or vertical jaw relationships, occlusal appliance/orthotics today should be viewed as "oromandibular crutches," which are analogous to back braces or ankle support orthotics because they support the joint and provide symptomatic relief while the joints are recovering. Table 63.4 outlines Klasser's conclusions on occlusal appliance use and limitations.

Most often, painful internal derangement causes a reactive muscle response. This muscle response and myalgia can be treated by soft diet, heat, and massage to the affected muscles, limiting the range of motion to within the pain-free range, NSAIDs, muscle relaxants, physical therapy, and even botulinum toxin injections (e.g., Botox).

**Table 63.4** Occlusal appliance/orthotic device limitations [50]


#### **63.6.2 Surgical Treatment** (Fig. 63.10)

The vast majority (approximately 90%) of TMD patients will experience symptom resolution either spontaneously or with nonsurgical treatment [51]. This resolution of symptoms occurs due to the underlying adaptive capacity of the TMJ. Given that internal derangement is a common MRI fnding in 32–38% of asymptomatic patients and volunteers [16, 17] and that arthrocentesis or arthroscopy without disc repositioning is so successful, it is evident that the TMJ has the ability to adapt to the disc displacement in the vast majority of patients. Those patients with internal derangement and disc displacement that do not adapt are potential surgical candidates. It is the authors' preference to follow a surgical pyramid algorithm with most patients beginning with arthroscopy unless there are specifc indications otherwise (e.g., ankylosis). Since no single surgical procedure carries a 100% success rate, patients who fail one level (phase 1) on the algorithm progress further up the pyramid to a second (phase 2) surgical procedure with phase 2 procedure being determined by the arthroscopic fndings of phase 1.

#### **63.6.3 Arthrocentesis**

This minimally invasive procedure was introduced after the success of simple arthroscopy was recognized. Arthrocentesis in the TMJ was frst described in 1987 by Murakami using a single needle pumping technique to create a hydraulic distention of the upper joint space [52]. Nitzan and Dolwick [18] subsequently modifed the technique and used two needles. It provides lysis and lavage of the upper joint space

**Fig. 63.10** Surgical treatment options

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 63.11** Arthrocentesis—using the Holmlund-Hellsing markings measured along the trago-canthal line (10 mm forward from mid-tragus and 2 mm down correspond to the glenoid fossa entry site)

using an infow needle, an outfow needle, and at least 300 ml Lactated Ringer's irrigation solution (Fig. 63.11). The lysis is accomplished by the hydraulic distention of the superior joint space, while the lavage removes infammatory mediators, cytokines, and debris (Fig. 63.12). It is through the lysis and lavage that the adhesions are separated and the infammatory mediators and debris are removed. Several authors have since reported success rates of arthrocentesis in the management of internal derangement ranging from 70 to 95% [18–22].

#### **63.6.4 Arthroscopy**

Minimally invasive arthroscopic surgery for the TMJ was frst performed by Ohnishi in 1974 and subsequently developed in the 1980s by several surgeons (Murakami, Holmlund, McCain, Saunders, and others). TMJ arthroscopy has proven to be an effective and reliable alternative to open joint surgery for many patients, resulting in reduced pain and improved maximum incisal opening [10–15] with success rates as high as 91% [12]. TMJ arthroscopy can be as simple as a visually assisted lysis and lavage or as complex as performing disc repositioning and fxation. The author uses McCain's terminology to categorize different levels of arthroscopy according to complexity and number of portals of entry (Table 63.5).

The authors preferred surgical sequence for performing a level 1 arthroscopy as outlined in Table 63.6 (Video 63.1). All arthroscopy should begin with an examination under anesthe-

#### Arthrocentesis


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 63.12** Arthrocentesis—lysis and lavage

**Table 63.5** Levels of TMJ arthroscopy (McCain's terminology)

#### **Level I Arthroscopy**


#### **Level II Arthroscopy**


#### **Level III Arthroscopy**


#### **Table 63.6** Level 1 arthroscopy sequence


sia of the TMJ. The EUA allows the surgeon to anticipate what might be encountered upon entering the joint arthroscopically. The range of condylar translation is noted, and whether translation is onto the peak of the articular eminence stops short of the peak or beyond the peak of the eminence as in subluxation and even dislocation. In addition, if there is very limited translation or just hinging, the surgeon might expect a tight joint space flled with adhesions and a fbrous arthrosis potentially making the arthroscopic puncture, joint access, and visualization diffcult. Joint noises (clicking and crepitation) should be noted, and bone-on-bone crepitations are indicative of a perforation in the retrodiscal tissue.

In addition to the lysis and lavage as in arthrocentesis (Table 63.6), a level 1 arthroscopy provides a diagnosis and identifes intra-articular pathology (Fig. 63.13a–f). A systematic diagnostic sweep through the entire superior joint space is performed to obtain the diagnostic information. Level 1 arthroscopy can be accomplished using a standard operative arthroscope (usually 1.9–2.7 mm) or the more recently available disposable scopes (1.2 mm). While the image quality from a disposable scope is currently not as good as the traditional operative arthroscopes, it does allow for adequate visualization and a diagnosis.

Level 2 arthroscopy includes a second puncture with an operative cannula and allows for additional procedures such as disc mobilization, biopsy, laser ablation, or coblation to be performed. Video 63.2 shows the second cannula being inserted, disc mobilization with a probe, and laser ablation of hyperplastic polypoid synovitis.

Level 3 arthroscopy with multiple cannulas allows for more advanced techniques and disc repositioning with fxation, using sutures, wires, pins, or screws. The author uses a suture technique to anchor the repositioned disc as shown in the Video 63.3. Figure 63.14a, b shows the suture placed through the posterior band of the disc anchoring it into the reduced position. The arthroscopic suture video clearly shows how tightening the suture reduces the anteriorly displaced disc.

Several surgeons have described and published techniques to reposition and fxate the displaced disc [53–59]. Success in the early reports of arthroscopic disc repositioning was not high. Yang reported better success rates with partial and later complete anterior release of the disc from its anterior attachment and suggested that relapse rates without complete anterior release are high [55]. While more recent success rates of disc repositioning as high as 95.3% [60] have been reported, many of these studies have relatively short-term follow-up and/or no MRI confrmation of longterm stability of the disc repositioning.

It is the authors' opinion that level 3 arthroscopy should be performed primarily for functional reasons, e.g., a mechanically obstructive click, closed lock, or subluxation. In McCain's publication on arthroscopic discopexy [59], the

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 63.13** (**a**–**f**) Arthroscopic pathology. (**a**) Retrodiscitis (**b**) Adhesions (**c**) Small disc tear/perforation (**d**) Large perforation with condyle visible (**e**) Villonodular synovitis (**f**) Polypoid synovitis

**Fig. 63.14** (**a**, **b**) Arthroscopic suture discopexy—suture placed through the posterior band of the disc anchoring it into the correct reduced position

©Association of Oral and Maxillofacial Surgeons of India

success rate in 42 joints was 86.7% in Wilkes II and III but only 25% in Wilkes IV and V which emphasizes that case selection is a key element to success. For disc repositioning to be indicated and have good outcomes, the disc must be salvageable, and there must be suffcient posterior joint space height in which to reposition the disc. In other words, the disc must be intact, and MRI evaluation must confrm normal disc morphology with adequate posterior joint space height in which to reposition the disc. If the joint space has collapsed as is often the case in longer-standing/chronic disc displacement, the load placed during function on the repositioned disc will be excessive, and the fxation will likely fail, leading to displacement again. Postoperatively, all patients will notice a malocclusion with slight mandibular deviation to the contralateral side. However, the majority of these malocclusions will resolve within 3 weeks. Additional factors to success are the postoperative physical therapy and dietary instructions. The author instructs his patients to perform "limited range of motion" exercises for the frst 3 weeks to minimize the risk of the fxation failing or tearing through the disc. This is achieved by instructing the patient to keep the tongue on the roof of the mouth while performing opening exercises. The diet should be soft with minimal chewing and as for all surgical cases and any parafunctional habits should be well controlled. After 3 weeks, the patients gradually increase their mouth opening with daily stretching exercises. Associated myalgias may improve once the joint pain and function improve following arthroscopy, but often concomitant nonsurgical treatment of the muscle disorder is also required.

At the end of the arthroscopic procedure, the surgeon has the option of injecting medications including steroid, hyaluronic acid (HA), and platelet-rich plasma (PRP).

#### **63.6.4.1 Viscosupplementation with Hyaluronic Acid**

Hyaluronic acid is a glycosaminoglycan polysaccharide naturally found in synovial fuid. It is produced by the chondrocytes and synoviocytes and plays an important role in joint function and nutrition. HA is the main contributor to the viscosity of synovial fuid and provides protection under joint loading. Infammatory disorders of the TMJ including internal derangement are associated with reduced quantity and quality of HA through a process of destruction and also the production of HA that is lower in molecular weight [61, 62]. The short half-life of injected HA makes it unlikely that its effectiveness is due to restoration of the viscosity of the synovial fuid [63]. It is suggested that supplementation with injectable HA could have anti-infammatory and analgesic effects [64]. Altman suggested that injection of HA could lead to repair of the articular cartilage/fbrocartilage and normalize the synthesis of endogenous HA [65].

Viscosupplementation has been described in orthopedic literature for many years, but there are discrepancies in the evidence to support the widespread use of intra-articular hyaluronic acid to treat knee osteoarthritis. However, several recent studies have shown hyaluronic acid to be a viable treatment option showing longer-term improvement in both knee pain and function. Unfortunately, similar uncertainty exists regarding the effectiveness of viscosupplementation using hyaluronic acid in the TMJ [66–68]. Beyond viscosupplementation, there are some additional benefts to using HA in TMJ arthroscopy. If the surgeon is having diffculty maneuvering the scope because of a tight joint space, the lubricant properties of HA may be helpful in minimizing iatrogenic damage to the joint surfaces and disc. It is also helpful at the end of the procedure in reducing the bleeding from a hyperemic joint.

#### **63.6.4.2 Platelet-Rich Plasma**

Is a concentration of platelets and growth factors taken from autologous blood. It has reported benefcial effects in joint degeneration and tendinopathy [69–72], and there is both literature supporting its effectiveness in TMJ arthroscopy [73–75] and conficting literature reporting no beneft [76, 77]. Therefore, the use of PRP after TMJ arthroscopy remains controversial, and further studies are needed [78].

#### **63.6.4.3 Open Joint Surgery and Arthroplasty**

The effectiveness of minimally invasive procedures such as arthrocentesis and arthroscopy has signifcantly reduced the frequency and volume of open joint surgery (disc repositioning or discectomy). However, currently there are very few surgeons trained in the advanced technique of arthroscopic discopexy, and so for patients who fail level 1 or 2 arthroscopy and require disc repositioning surgery, open joint surgery with disc repositioning may be the next surgical step in moving up the surgical pyramid. Annandale frst published "On displacement of the inter-articular cartilage of the lower jaw and its treatment by operation" in 1887 [3], but it wasn't until later that surgery for internal derangement became popular. Surgical interest in disc displacement began with reports from McCarty and Farrar [5] claiming disc repositioning success rates of 94% using a wedge resection and suture plication technique. However, other surgeons were not as successful, and the long-term stability of suture plication techniques was low, leading to multiple variations of open surgical disc repositioning and methods of fxation [79–82]. In 2001, Wolford reported a more rigid fxation technique using a Mitek mini-bone anchor to fxate the repositioned disc [83]. In this technique, the anterior and lateral disc attachments are released allowing passive disc repositioning. The disc is separated at its junction with the retrodiscal tissue, and Mitek anchor is inserted into a 2-mm hole drilled into the posterior condyle 8–10mm below articulating surface. Two 0-Ethibond braided sutures are inserted through the posterior band of the disc in a mattress suture fashion fxing the disc to the Mitek anchor (Fig. 63.15a–c). Although radiographs at the longest follow-up showed no condylar resorption and stable position of the metal anchor, the stability of the disc repositioning was not evaluated by MRI. Despite this, Wolford reported that there was a statistically signifcant reduction in TMJ pain, facial pain, headaches, TMJ noises, and disability and improvement in jaw function and diet.

Alternative fxation and anchoring devices are available on the market today. He et al. use a self-drilling miniscrew and have modifed the technique to include a complete anterior release and overcorrection of the disc position for better stability of the repositioning. They report stable short-term (mean 10 months) disc position on MRI in 98.6% of patients [84]. Zhou et al. evaluated the same technique in 149 joints and the long-term stability of the repositioned disc on MRI at a mean longest follow-up of 23.4 months (range 12–84 months) and reported that 95.3% of discs were still in position, whereas 4.7% had relapsed anteriorly [85]. They also reported new condylar bone formation in 74.5% of joints and even greater in young patients (under the age of 20), 90% of whom had new bone formation, suggesting that adolescents may have growth ability after disc repositioning which might reduce facial asymmetry. Mandibular asymmetry in unilateral disc displacement has been reported in the literature. Xie et al. [86] reported mandibular asymmetry in 72% of 165 patients with anterior disc displacement and the severity of the asymmetry correlated with the degree of disc displacement, disc deformity, and condylar shortening. Therefore, disc repositioning may allow for condylar bone formation and reduce mandibular asymmetry that may develop as a result of the displaced disc. The overall clinical outcomes of disc repositioning surgery are good with reduced pain, improved diet, and improved range of motion with 94% of patients reporting improved quality of life [87].

For those patients with discs that are not salvageable, discectomy is the next step in the surgical pyramid. This involves removal of the disc and the area surrounding any perforation in the retrodiscal tissue, and possible replacement of the disc is an option. There are several long-term studies demonstrating greater than 80% success rates following discectomy [88–91] with a few following patients for more than 20 years [92–94] with almost complete resolution of pain and restoration of normal diet. A 5-year follow-up study of discectomy without any disc replacement reported 87% of patients fulflling the criteria for success with reduced pain on function and increased mouth opening, although pain at rest was unchanged [95]. Following discectomy, radiographs will show altered condylar morphology in the operated joint, and this is thought to be an adaptive process of remodeling because the reduced symptoms do not correlate with the radiographic changes [96, 97]. While the literature demonstrates the long-term success of discectomy without replacement [89, 90], disc replacement options have been explored in attempts to reduce the crepitation these patients experience and also with the intent to reduce the

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remodeling. Many autogenous, allogeneic, and alloplastic disc replacements have been tried with varying degrees of success (Table 63.7), and some such as Proplast have caused joint destruction necessitating joint reconstruction and replacement [99]. At the current time, there is a lack of evidence to support the routine use of any disc replacement after discectomy.

The use of tissue engineering is emerging as a promising option to repair or potentially replace the diseased tissues of the TMJ and may provide additional treatment options in the future. Progress has already been made toward the development of appropriate tools for TMJ tissue engineering. The goal is to develop an approach to produce new tissues de novo (neotissues) with qualities similar to the native TMJ. This may be accomplished by (1) in situ tissue engineering, which involves an acellular scaffold matrix attracting local cells (cell homing) guiding the process of regeneration, and (2) ex vivo cell seeding on



the scaffold, which provides enough competent cells to orchestrate the regenerative process. The second strategy appears better suited for TMJ regeneration because of its limited capacities of self-repair and the rapid regeneration expected [100].

**Table 63.8** Failed level 1 or 2 arthroscopy—now what?


sion framework

#### **63.7 Conclusion**

Internal derangement of the TMJ is a common problem resulting in pain and limited function for some patients. While the vast majority of patients adapt to the internal derangement over time or with nonsurgical treatment, surgery may be indicated for those with ongoing problems. There are no surgical procedures for the TMJ that have a 100% success rate; it therefore makes sense to undertake the least invasive procedures frst. The surgical pyramid presented in this chapter provides a stepwise progression for TMJ surgical patients. In the authors' clinical practice, most surgical patients begin with a level 1 or 2 arthroscopic surgery and only step up the pyramid if this fails. If the diagnosis after arthroscopy is Wilkes II, III, or early IV, phase 2 procedure would be disc repositioning and discopexy if the disc is intact and has normal morphology and there is suffcient posterior joint space in which to reposition it. In Wilkes IV and V, phase 2 procedure would be joint debridement and discectomy (Table 63.8).

Finally, Table 63.9 presents an algorithm and decision framework that guides the progression through the various surgical procedures discussed in this chapter.

#### **References**


lar disorders: a systematic review. J Craniomaxillofac Surg. 2018;46(11):1943–52.


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## **Temporomandibular Joint Dislocation**

V. B. Krishnakumar Raja

#### **64.1 Introduction**

Hypermobility disorders of the temporomandibular joint (TMJ) present in two major forms:


The differences between dislocation and subluxation have been highlighted in Box 64.1.

The condyle may be displaced either anteriorly, posteriorly, medially, or laterally of which anterior dislocation is the most common [1]. The incidence of TMJ dislocation constitutes about 3% of the dislocations occurring in other joints of the body with female predilection. The reported incidence of TMJ dislocation is 7% with a preponderance in people in the second and third decades [2].

#### **Box 64.1 Defnition of Dislocation and Subluxation**

Dislocation refers the phenomenon in which condyle is displaced out of the glenoid fossa and traverses in front of the articular eminence. In contrast, subluxation is the condition in which the dislocated condyle can be reduced back into the normal position by patient themselves, without any professional assistance.

### **64.2 Classifcation** (Box 64.2)

Dislocation has been classifed by numerous methods. Rowe and Killey [3] based it on the duration of the dislocation episode as:

V. B. Krishnakumar Raja (\*)

Department of Oral and Maxillofacial Surgery, SRM Dental College and Hospital, Ramapuram, Chennai, Tamil Nadu, India

#### **Box 64.2 Classifcation of Dislocation**

*Based on duration of displacement*


*Based on direction of displacement*


Dislocation recurring more than once is termed as chronic recurrent dislocation. The term *chronic protracted dislocation* is used to describe dislocation persisting for more than 1 month, while dislocation present for more than 6 months is called *extra-long-standing dislocation* [4].

Based on the direction of displacement [2], dislocation may be categorized as:


Anterior dislocation is the most common type of dislocation due the weakness of the capsule in the anterior region.

**64**

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1381

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_64

©Association of Oral and Maxillofacial Surgeons of India

Posterior dislocation occurs following fracture of the external auditory canal and skull base. Allen and Young classified lateral dislocation into Type I and Type II. This type of dislocation occurs in mandibular trauma (Fig. 64.1a, b):


Superior dislocation results when condyle is pushed into the middle cranial fossa accompanied by glenoid fossa fracture. Small and round-shaped condyle is predisposed to this type of dislocation [2].

#### **64.3 Etiopathogenesis** (Table 64.1)

A multitude of causes have been described in the etiopathogenesis of TMJ dislocation including congenital, iatrogenic, anatomical aberrations, spontaneous, pharmacological, neurological, neuromuscular, etc. Proper diagnosis of the etiology is important to institute problemspecifc treatment.

#### **Table 64.1** Etiology of dislocation


Daily activities which involve wide mouth opening such as laughing, yawning, and biting may induce TMJ dislocation. It may also occur spontaneously during epileptic seizures, vomiting, yawning, and singing. Trauma is another cause which might cause posterior, superior, and lateral dislocation in addition to anterior dislocation [5]. Iatrogenic causes include dental procedures which require wide mouth opening for prolonged time, intubation procedures, gastrointestinal endoscopy, and laryngoscopy/bronchoscopy. Anatomical aberrations such as small condyle, underdeveloped glenoid fossa, shallow/steep articular eminence and laxity of ligaments and capsule are more prone for dislocation.

Predisposing risk factors include connective tissue disorders such as Ehlers-Danlos disease and Marfan's syndrome which predispose to laxity of the joint and hypermobility. Muscle spasms occur in neurodegenerative or neurodysfunctional diseases, namely, Huntington disease, Parkinson disease, multiple sclerosis, muscle dystrophies, or dystonias.

Medications which induce dislocation are antipsychiatric (phenothiazines) and antiemetic (metoclopramide) drugs which produce unwanted extrapyramidal reactions which eventually lead to muscular imbalance attributed to dislocation.

Reduced vertical dimension due to loss of posterior teeth in advanced age may also predispose an individual to dislocation [5].

Though various theories of pathogenesis have been described in literature, the most accepted was muscular incoordination during mandibular movements. In the initial stages of mouth closure, elevators are activated prior to the relaxation of depressors mainly lateral pterygoid which pulls the condyle forward. This initial dislocation facilitates the further dislocation [5].

**64.4 Clinical Features** (Mentioned in Box 64.3; Figs. 64.2a, b, 64.3, 64.4a, b, and 64.5a, b**)**

#### **Box 64.3 Clinical Features of Dislocation**

The classical clinical features of dislocation are:


Unilateral dislocation is associated with deviation of chin towards contralateral side.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 64.2** (**a**, **b**) Bilateral TMJ dislocation. (**a**) Before reduction (**b**) After reduction

### **64.5 Investigations**

• *Orthopantomogram* (OPG) (open and closed) (Fig. 64.6) This is the commonly used screening modality for the examination of TMJ. Morphology of condyle, articular eminence, and joint space can be evaluated. Open mouth OPG shows the position of the condyle in relation to the articular eminence.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 64.3** Bilateral TMJ dislocation showing openbite

• *TMJ tomogram*

Open and closed mouth TMJ images can be obtained in different slices.

• *Computed tomography(CT)*

Evaluation of the morphology of osseous TMJ components—condyle, articular eminence and the glenoid fossa—are better assessed with CT.


©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 64.5** (**a**, **b**) Unilateral TMJ dislocation on the right side. (**a**) Before reduction (**b**) After reduction

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 64.6** OPG demonstrating dislocation. A: Articular eminence. B: Condyle in front of articular eminence. C: Glenoid fossa

#### **64.6 Management of Dislocation**  (Box 64.4)

#### **64.6.1 Acute Dislocation**

Reducing the dislocated condyle poses a great challenge. Reduction is more complicated with the accompanied muscle spasm persisting for longer duration. In diffcult situations, reduction can be facilitated with the help of local anesthesia, conscious sedation, and general anesthesia. Following reduction, a Barton's bandage, chin strap, or intermaxillary fxation is advised for 3–6 weeks to prevent further dislocation. Several reduction techniques have been employed with varying rates of success.

#### **Box 64.4 Management of Acute Dislocation**


#### **64.6.1.1 Hippocratic/Nelaton's Technique**  (Fig. 64.7)

This is the conventional method of reduction of acute dislocation in which physician stands in front of the patient, with the thumb placed either on the external oblique ridge or on the lower molars and other fngers positioned along the lower border of the mandible. A steady downward, backward, and superior force should be given to reduce the dislocated condyle. The thumb should be protected either with a plastic splint or gauze wrapped around it to prevent injury to the thumb while reducing dislocation.

#### **64.6.1.2 Gag Refex [3]**

Gag refex is induced by probing the soft palate using mouth mirror. In alert individuals, this refex relaxes the lateral pterygoid muscle through coordinated neuromuscular activities which reduces dislocation in natural way.

#### **64.6.1.3 Wrist Pivot Method [7]** (Fig. 64.8)

This method utilizes existing myospasm of the elevators for reduction. The thumb is placed under the chin, while other fngers are placed over the occlusal surfaces of lower teeth.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 64.7** Nelaton's method. A: Thumb intraorally on the occlusal surface lower teeth. B: Other fngers at the inferior border of body and angle of the mandible

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 64.8** Wrist-pivot method. A: Other fngers intraorally on the occlusal surface lower teeth. B: Thumb on the chin

Then upward movement is applied by the thumb, and concomitant inferior force is given by other fngers with pivoting the wrist. The advantage of this technique is that it utilizes the force created by the muscles of mastication rather than overcoming this force as in Nelaton's technique.

#### **64.6.1.4 Extraoral Method [8]** (Fig. 64.9a, b)

Intraoral methods described previously have the risk of human bite in which there are chances of infection transmission. To overcome this, extraoral method has been described. In the dislocated mandible, coronoid process comes forward which is easy to palpate. On one side, the thumb is positioned over the coronoid process which pushes the mandible backward, while the other fngers are located over the mastoid process to deliver counteracting force (Fig. 64.9a). On the other side, the mandible is pulled further forward with the thumb on the malar eminence and rest of the fngers on the mandibular angle (Fig. 64.9b). Pulling the mandible on one side with simultaneous pushing of the mandible on the other side reduces the dislocation on one side frst and then subsequently on the other side. This technique is applicable in unilateral dislocation as one side is reduced frst and then the other is reduced thereafter.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 64.9** (**a**, **b**) Extraoral method for reduction of dislocation. (**a**) A: Thumb on coronoid process. B: Other fngers on mastoid process. (**b**) A: Thumb on malar eminence. B: Other fngers on angle of the mandible

#### **64.6.2 Management of Chronic Recurrent Dislocation/Subluxation** (Box 64.5 and 64.6)

**Box 64.5 Management of Chronic Recurrent Dislocation/ Subluxation**

#### *Conservative*


#### *Minimally invasive*


#### **Box 64.6 Management of Chronic Recurrent Dislocation/ Subluxation**

#### *Surgical procedures*

	- (a) Capsulorrhaphy
	- (a) Dautrey's procedure
	- (b) Glenotemporal osteotomy
	- (a) Eminectomy
	- (b) Condylectomy
	- (a) Temporalis scarifcation
	- (b) Lateral pterygoid myotomy
	- (c) Pterygoid dysjunction

Numerous treatment modalities have been described for TMJ dislocation, as it has multifactorial etiology. Miller and Murphy [9] proposed a comprehensive list of treatment options which targeted specifc anatomical sites of the joint that exhibited abnormality: the capsule, eminence, and condylar head.

For practical purposes, the types of management may be broadly classifed based on the degree of invasiveness as:


#### **64.6.2.1 Conservative Methods**

Conservative methods may be used following reduction of dislocation to prevent further dislocation, such as:


©Association of Oral and Maxillofacial Surgeons of India

Intermaxillary fxation, chin strap, and Barton's bandage are done for 4 weeks to induce fbrosis of soft tissues around the joint so that further dislocation is prevented. Physiotherapy including ultrasound and infrared therapy are advised to reduce pain. Isotonic and isometric exercise are advised to strength the muscle involved in TMJ function [9].

#### **Kinesio Taping** (Fig. 64.11)

In the year 1970, Dr. Kenzo Kase, a Japanese chiropractor, frst described the techniques of Kinesio taping. The thin elastic tape acts by lifting the skin which increases the blood and lymphatic fow, thereby reducing infammation and accumulation of pain mediators. It also helps in better muscle function and joint realignment which is utilized in reduction of TMJ dislocation.

#### **64.6.2.2 Minimally Invasive Treatment**

#### **Injection of Sclerosing Solutions [9]**

This procedure involves repeated injection of sclerosing solution into the capsule aimed at fbrosis of the capsule which would eventually limit the mouth opening. The solutions commonly used to perform the procedure are:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 64.11** Kinesio taping

These injections are usually given intra-articularly and in pericapsular region and can be repeated every 2–3 weeks till the fbrosis occurs. However, the outcome of this technique is not satisfactory and is also associated with complications such as TMJ ankylosis and facial nerve injury [9].

OK-432 which is a streptococcal derivative inactivated by penicillin G is used as sclerosing agent for the treatment of TMJ dislocation. A 21-gauge needle is used to inject 1.25 KE/ml concentration of OK-432 into the superior joint space and pericapsular region. 2 ml of the solution is injected in each region. This produces fbrosis in and around the joint by inducing local infammation and formation of granulation tissue. Mouth opening is restricted for 4 days following injection by elastic bandage.

#### **Autologous Blood Injection [1]**

This procedure works by producing fbrosis which restricts the opening of the mouth wide. It involves injection of patient's own blood into the superior joint space and pericapsular region following two puncture arthrocentesis. Prior to the injection of blood into the joint, lavage should be done using two needles in the superior joint space, and then one needle is removed. Blood is injected through the other needle into the joint and around the joint. It may be injected either unilaterally or bilaterally. It can be given as a single or multiple injections with intervals.

#### **Injection of Platelet Rich Plasma (PRP) (Refer suggested reading at the end of the chapter)**

Platelet rich plasma is a yet another minimally invasive technique used to treat various Temporomandibular joint disorders. It is prepared from 10 ml of patient's own blood which was centrifuged at 3200 rpm for 12 minutes. The 2ml solution was then injected it to the superior joint space which was located 10 mm forward and 2 mm downward on the canthotragal line. Another 1ml of the solution was injected into the pericapsular tissues. Patients were advised for various mandibular movements for a minute following injection for the equal distribution of PRP in the joint. Elastic bandage is given for a week followed by mandibular exercise advised. PRP has 3-8 folds concentration of platelets and various growth factors such as platelet derived growth factor, transforming growth factor beta and vascular endothelial growth factor which helps in healing of the tissues. In a comparative study between autologous blood injection and PRP for TMJ dislocation demonstrated both groups were equally effective in decreasing mouth opening in TMJ dislocation.

#### **Prolotherapy** [1]

It is also called as regenerative injection therapy. This involves injection of solutions into the joint to stimulate regeneration potential. Various prolotherapy solutions are available such as psyllium oil, glycerin, phenol, etc. of which

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 64.12** Injection sites for prolotherapy. A: Posterior joint space. B: Anterior attachment of disc to lateral pterygoid muscle. C: Most tender point of masseter muscle

dextrose is the most commonly used solution. 2 ml of 10–50% dextrose can be injected in and around the joint space. Either single or multiple injections are needed based on severity of dislocation. This technique is indicated in laxity of the ligaments and capsule. It induces low-grade infammation which releases growth factors. These growth factors stimulate fbroblasts which deposit new collagen fbers that strengthen ligaments and tendons.

Landmarks—prolotherapy solutions are given in the following three points (Fig. 64.12):


#### **Injection of Botulinum Toxin** [1]

The frst reported use of botulinum toxin for TMJ dislocation was described by Daelen et al. in the year 1995. Botulinum toxin type A weakens the skeletal muscle when injected by preventing the release of acetylcholine at the neuromuscular junction. It can be injected into any of the masticatory muscle, but injection into lateral pterygoid muscle is effective because forward movement of condyle is prevented. The dosage used is 25–50 units of botulinum toxin. It can be injected either by extraoral or intraoral route with or without EMG guidance (Refer Chap. 33 on Botox injections).

#### Extraoral Technique

A 30-gauge needle is inserted into the skin 1 cm below the central zygomatic arch to the depth of 3–4 cm based on the measurements obtained from computed tomogram of the patient. The 25–50 units of toxin is deposited into the lateral pterygoid muscle following aspiration.

#### Intraoral Technique

Hypodermic needle electrode is inserted in the mucobuccal fold of distal root of upper second molar directed superiorly and posteriorly to the depth of 25–30 mm; the position of the needle in the lateral pterygoid muscle is confrmed by EMG reading. After aspiration, 25–50 units of toxin is deposited into the muscle.

The injection should be repeated every 3–6 months as the action of this toxin lasts within 6 months. Complications of this technique included dysphagia, dysarthria, and hemorrhage.

#### **Arthroscopy** [1] **(Refer** Chap. 63 **on Internal Derangements of TMJ)**

Arthroscopic capsulorrhaphy is done by using either laser or cautery which produces contractions. Sclerosing solutions may be injected into the joint and capsule under direct visualization using arthroscopy.

#### Arthroscopic Capsulorrhaphy

A 1.7 mm TMJ arthroscope is introduced into the fossa portal following the double puncture technique described by McCain. Once the arthroscope reached the anterior recess, the second puncture is done using triangulation technique. Deep lesional burns are created in the oblique protuberance, laterally and the posterior wall using either bipolar cautery or holmium laser which causes shortening of the capsule.

#### Arthroscopic Eminectomy

The arthroscope is introduced into the joint through inferolateral approach, and then the articular eminence is reduced by electronic shaver which is introduced by triangulation technique.

#### **64.6.2.3 Surgical Treatment**

The following is a brief description of surgical procedures which are commonly employed for treating TMJ dislocation.

#### **Capsular Tightening Procedure**

Temporomandibular joint is completely covered by capsule which is attached superiorly from all around the rim of the glenoid fossa and inferiorly till the neck of the condyle. This capsule holds the joint components in position, which is later-

**Fig. 64.13** (**a**–**b**) Capsulorrhaphy. Excised margin of the capsule. (**A**) Capsule is tightened by suturing it to the adjacent soft tissues (**B**)

ally strengthened by lateral ligament. Lax capsule is considered as one of the reasons for TMJ dislocation. So, capsular tightening procedures are done to address this problem.

#### Capsulorrhaphy (Fig. 64.13a, b)

This procedure was frst implemented in the year 1907 by Perthes who excised a portion of the lateral capsule and sutured it together to increase the tautness of the capsule and thus restrain condyle. Later on, many modifcations had been proposed including suturing of the capsule to zygomatic arch and overlapping of the capsule after making vertical incision on the capsule [9].

#### **Creation of Mechanical Obstacle**

Excessive translation of the condyle which is observed in dislocation is prohibited by creating impediment in the path of the condyle. Konjetzny (1921) had used articular disc as a mechanical impediment by bringing it forward and suturing it anteriorly. Lindemann and Mayer used articular tubercle to prevent condylar dislocation by either bending it down or placing a graft obtained from zygoma [9].

#### Dautrey's Procedure [10] (Fig. 64.14a, b)

Mayer (1933) created a mechanical obstacle by dislocating a part of the zygomatic arch down, in front of the articular eminence. Vertical osteotomy of the zygomatic arch and repositioning the osteotomized arch downward as a mechanical impediment has been described by LeClerc and Girard in the year 1943.

In 1967 Gosserez and Dautrey made an oblique osteotomy of the arch in front of the articular eminence extending from posterior-superior to the anterior-inferior direction. With gentle pressure towards inferior direction, a greenstick fracture was created at the zygomatico-temporal suture. The segment was then pushed downwards to create obstruction for the condylar movement. If this downfractured segment is unstable, plating can be done to prevent displacement (Fig. 64.15).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 64.15** Fixation of downfractured zygomatic arch segment using miniplates

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 64.14** (**a**, **b**) Dautrey's procedure. (**a**) A: Osteotomy of zygomatic arch (**b**) A: Proximal segment of zygomatic arch. B: Downfractured distal segment of zygomatic arch

The limitations of the technique include the following:


#### Glenotemporal Osteotomy (Fig. 64.16a, b and c)

Norman [10] described glenotemporal osteotomy as a defnitive technique for dislocation. TMJ is exposed through any of the open surgical approaches described for TMJ, without violating the capsule. An oblique osteotomy on the articular eminence is made, following which the fragment is gently moved downwards to create a wedgeshaped defect which is grafted using bone taken from ilium, calvarium, symphysis, etc. Usually it is not necessary to fx these grafts as they stay in that wedge-shaped space created by osteotomy. Miniplates or screws can be placed on the eminence so that excessive condylar translation is prevented. Long-term results of this technique showed screw loosening and fracture of the plate.

#### Modifcations of Norman's Procedure

Sharma et al. [11] added two modifcations to the conventional glenotemporal osteotomy. Temporalis fascial fap was used to strengthen the capsule, and pterygoid dysjunction was performed to address the TMJ pain due to internal derangement which coexists with dislocation.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 64.16** (**a**, **b**, **c**) Glenotemporal osteotomy. (**a**) A: Articular eminence. (**b**) A: Osteotomy of articular eminence. (**c**) A: Chin graft in position. B: Downfractured articular eminence

#### **Removal of Mechanical Obstacle**

#### Eminectomy (Fig. 64.17a, b)

The frst reported evidence of eminectomy for the treatment of TMJ dislocation was performed by Hilmar Myrhaug in the year 1951. This procedure is generally accomplished under general anesthesia or local anesthesia, or conscious sedation has also been used for patients with systemic conditions that prohibit general anesthesia. Though there are many techniques available to address this condition, this particular technique may be considered for those patients with neurological disorder, epilepsy, and advanced age [12].

Hall et al. [13] had studied the eminence confguration using 38 cadavers. The observations included the following:


Articular eminence thicknesses in anterior and posterior regions were also mentioned [6]. These measurements provide guidelines while performing eminectomy procedure to avoid complications.

According to this technique, the joint may be approached through any of the incisions indicated for TMJ surgeries. Following exposure of the eminence, rotary instruments, osteotome, chisel, or piezo surgery device can be used to reduce the height of the eminence. Either total eminectomy or partial eminectomy may be done. Irregular bony surfaces and edges should be smoothened well. Segami et al. [14] described arthroscopic eminectomy where double puncture

A

tures [11].

is used to cut the condyle as described by Kostecka [2]. Part of the condyle is removed to prevent the obstruction;

at the same time, it allows the free translation of the condyle along the articular eminence. Preauricular incision is used to approach the condyle, and

then the condyle is sectioned at the inferior level of the articular eminence.

#### **Creating New Muscular Balance**

• *Temporalis Scarifcation* [1]

A portion of the temporalis muscle is removed by this technique so that the scarring and fbrosis induced by surgery restrict the mouth opening.

• *Lateral Pterygoid Myotomy* [1] (Fig. 64.19a, b)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 64.17** (**a**–**b**) Eminectomy. (**A**) Articular eminence **(B**) Eminence removed

technique has been used. Motorized shaver was used to reduce the eminence.

Navigation system has also been used for accurate reduction of eminence especially on the medial side and superior surface to avoid intracranial exposure [6].

Eminectomy works by allowing free movement of the condyle over the eminence so that locking of the condyle is prevented. There are observations of reduced mouth opening following eminectomy that might be due to adhesions formed in and around the joint. This can be performed unilaterally or bilaterally [6].

The major problem associated with this technique is the excessive forward movement of the condyle than what is actually needed which leads to stretching of muscles and ligaments which is potentially injurious to the articular struc-

#### Condylotomy and Condylectomy (Fig. 64.18a, b)

Closed condylotomy is a blind procedure in which Gigli saw

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 64.19** (**a**–**b**) Lateral pterygoid myotomy. (**A**) Lateral pterygoid muscle (**B**) Part of the lateral pterygoid muscle excised (**C**) Barrier is placed

This technique was described by Bowman in 1949. This procedure may be performed through either intraoral by making incision along the anterior border of the ramus from coronoid to the third molar region or extraoral route through preauricular approach. Dissection is carried out to visualize the attachment of lateral pterygoid to condyle and capsule, and the attachment is then severed and then silastic sheet fxed to the anterior surface of the condyle. This results in restriction of mouth opening for short period of time.

#### Pterygoid Dysjunction

It is an intraoral procedure done to reduce the activity of the lateral pterygoid on the condyle so that forward movement of the condyle is reduced [11].

Intraoral vestibular incision is made in relation to the upper molars, and dissection is done to expose the posterolateral wall of the maxilla and pterygomaxillary suture. Pterygoid chisel is used to separate the pterygoid plates from maxilla, so that lateral pterygoid muscle along with pterygoid plate is detached.

#### **64.6.3 Chronic Protracted Dislocation** (Box 64.7)

**Box 64.7 Management of Long Standing Dislocation** *Conservative*

	- (a) Using a wire passing in the mandibular angle region
	- (b) Using a hook in the sigmoid notch

*Surgical procedures*

	- (a) Condylotomy, condylectomy
	- (b) Myotomy
	- (c) Joint prostheses
	- (a) Sagittal split osteotomy
	- (b) Vertical ramus osteotomy
	- (c) Inverted L osteotomy
	- (d) Midline mandibulotomy

Initially conservative method is employed to reduce dislocation. Manual reduction is attempted either using local anesthesia, sedation, or general anesthesia. Continuous elastic traction may also be applied with the bite block in the posterior region which might reduce the dislocation [15].

Indirect reduction can be performed by inserting wire into the mandibular angle region, or bone hook is passed into the sigmoid notch through a small incision made on the angle region (Rowe and Killey 1968) [4]. Lewis in 1981 used Bristow's elevator for the reduction by giving downward and posterior force.

In long-standing persistent dislocation, patient might have functional movement due to pseudo joint formation in front of the articular eminence. In this scenario, the goal is to establish the occlusion by osteotomy procedures such as sagittal split osteotomy or vertical ramus osteotomy.

Adekeye (1976) [4] suggested inverted L osteotomy instead of vertical and horizontal osteotomies due to the coronoid hindrance. Lateral and medial surface of the ramus is exposed either through submandibular incision or intraoral incision extending from the coronoid process along the anterior border of the ramus to the vestibule of second molar region. Medial osteotomy (horizontal cut) is performed 4–5 mm above and posterior to the lingula and parallel to the occlusal plane. Vertical cut is performed from the distal aspect of the horizontal cut to the mandibular angle. Then the dentate segment is manipulated to get the desired occlusion. Proximal and distal segments are fxed with miniplates.

Other methods such as condylectomy, condylotomy, and myotomy (as described in previous sections) and TMJ prostheses are proposed to treat this condition [4].

Ratten et al. described midline mandibulotomy to reduce the dislocation [16].

Through the intraoral approach, the mandible is sectioned in the midline, and then each hemimandible is manipulated to reduce the dislocation on each side separately. Following reduction, mandibular midline is fxed with miniplates.

#### **64.7 Recent Advances**

#### **64.7.1 Raja's Coronoid Repositioning Technique** [17]

This is a new technique performed for the management of TMJ dislocation. Intraoral vertical incision extending from the coronoid process to the molar region is made, and the coronoid and anterior border of ramus is exposed, and then coronoid is osteotomized and inferiorly pulled along with temporalis muscle and fxed with miniplates on the lateral surface of the ramus. The advantage of this technique is that the temporalis is stretched to give new muscle balance and restricts the excessive opening of the mouth.

### **64.7.2 Wolford's Anchoring Technique** [18]

(Fig. 63.15)

This technique prevents the dislocation by using two Mitek screw with attached suture material. One screw is attached to the zygomatic arch and another to the posterolateral surface of the condyle, and the sutures are tied together to get the desired mouth opening. These suture materials act as artifcial ligaments that control condylar movement.

**Acknowledgment** I would like to acknowledge Dr. Vijitha and Dr. Logitha for illustrations.

**Disclosure** Authors have no fnancial conficts to disclose.

### **64.8 Case Scenarios**

**Case 1** (Fig. 64.20a–d)

**Patient** A 24-year-old male, with complaints of locking of the jaw after wide mouth opening

*Preoperative open mouth OPG* revealed bilateral TMJ dislocation (Fig. 64.20a)

OPG demonstrates:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 64.20** Case scenario 1 (**a**) Pre op "open mouth "OPG showing bilateral dislocation of TMJ. (**b**) Osteotomy of articular eminence (yellow arrow). (**c**) Chin graft sandwiched between segments (yellow arrow). (**d**) Post op OPG showing increase in the height of articular eminence on right side

**Surgical plan** Augmentation of articular eminence by glenotemporal osteotomy on the right side. The right side was chosen for intervention as the symptoms were pronounced on that side

#### **Surgical procedure**


#### **Postoperative OPG**

OPG demonstrating increase in the height of articular eminence on the right side of TMJ (Fig. 64.20d)

#### **Case 2** (Fig. 64.21a–d)

**Patient** A 54-year-old female, with pain in front of the ear and diffculty in closing the mouth following yawning

*Preoperative open mouth OPG* demonstrated bilateral TMJ dislocation (Fig. 64.21a)

OPG demonstrates:


**Surgical plan** Inferior repositioning of the coronoid on the right side. The right side was chosen for surgery as the patient complained of more pain on that side

#### **Surgical procedure**


#### **Postoperative OPG** (Fig. 64.21d)

Open mouth OPG demonstrating the condyle within the glenoid fossa on both the sides and coronoid fxed inferiorly on the right side

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 64.21** Case scenario 2 (**a**) Pre- op "open mouth" OPG showing bilateral dislocation of TMJ. (**b**) Osteotomy of coronoid. (**c**) Inferiorly positioned coronoid fxed with 2 mm miniplate. (**d**) Post -op "open mouth" OPG showing normal positioning of condyle in relation to articular eminence

#### **References**


#### **Suggested Reading**

Yasso MM, Fahmy MH, Mohamad NS. Comparative study between Autologous Blood and Platelet Rich Plasma in Treatment of Recurrent Temporomandibular Joint Dislocation. Alex Dent J. 2018;43:101–107.

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#### **65.1 Introduction and Etiopathogenesis**

Temporomandibular joint (TMJ) ankylosis is defned as bony or fbrous adhesion of the anatomic joint components accompanied by limitation of mouth opening, causing diffculty in mastication, speech, and oral hygiene. This may also infuence symmetry of the facial skeleton, especially in cases which occur when patient is still in the growth phase [1].

According to Kaban [2], trauma is the most common cause (31–98%), followed by local or systemic infection (10–49%), and lastly any systemic disease (10%). Infection occurring in the joint commonly occurs due to spread from otitis media or mastoiditis or from the hematogenous route tuberculosis, gonorrhea, scarlet fever, etc. Systemic etiology may include ankylosing spondylitis, rheumatoid arthritis, or psoriasis.

Classically, hemarthrosis following trauma is the pathogenic factor for bone formation in TMJ ankylosis [3]. Condylar trauma may lead to hemarthrosis due to injury to the periosteum and capsular ligament. When this intracapsular hematoma organizes, hypertrophic bone is formed from the disrupted periosteum or metaplasia of non-osteogenic connective tissue. This may lead to hypomobility, and bony ankylosis may eventually develop.

Yan et al. in 2014 [4] put forth the hypotheses of hypertrophic nonunion. He described the sagittal fracture of condyle along with displacement of the disc. Herein, trauma also occurs in the glenoid fossa, thereby establishing the microenvironment in the articular surfaces for bone healing.

When the condylar trauma is recent, mouth opening will exert a dual effect on new bone formation. This is explained in Fig. 65.1. Restricted jaw movement is not a determinant but rather a promoting agent for ankylosis. Injuries to both the articular disc and the articular surfaces are prerequisites to TMJ ankylosis.

#### **65.2 Clinical Features** (Fig. 65.2)

In ankylosis, TMJ movements may be partially or completely restricted in opening, protrusion, and lateral excursions. Palpation of joint movements is better in fbrous than bony ankylosis. In children even in bony ankylosis, joint movements can be palpated because of stretching in the cranial sutures.

Ankylosis results in issues with mastication, digestion, speech, and oral hygiene. This may lead to caries, periodontitis, encumbered eruption of mandibular molars, crowding of teeth, and anterior open bite. Mandibular incisors often show supra-eruption and labial tipping as nature's compensation since the mandible is placed much posterior to the maxilla, thereby reducing lip competence. In severe cases, the lower lip may be trapped under the maxillary incisors.

As the vertical growth of the ramus is restricted, the lower face is signifcantly shortened. The digastric and mylohyoid muscles produce marked antegonial notching at the inferior part of the mandible just anterior to the insertion of the masseter and medial pterygoid. Failure of condylar growth impedes the forward and downward movement of mandible resulting in localized thickening of the bone at the angle due to subperiosteal apposition which accentuates the antegonion. The mandibular warping is caused due to this, as well as the obtuse angle between the inferior border of the mandible and the base of the skull [5]. The long-standing contractions of the masticatory muscles also give rise to elongation and thickening of the coronoid process, ramal shortening, and chin recession.

**65**

**Temporomandibular Joint Ankylosis**

Sonal Anchlia

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_65) contains supplementary material, which is available to authorized users.

S. Anchlia (\*)

Department of Oral and Maxillofacial Surgery, Government Dental College and Hospital, Ahmedabad, Gujarat, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1401

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_65

**Fig. 65.1** Dual effect of mouth opening on new bone formation in recent condylar trauma

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 65.2** (**a**) Unilateral ankylosis of the right side, (**b**) bilateral ankylosis

In unilateral cases, the chin deviates to the affected side due to restricted mandibular growth on the affected side and normal growth on the unaffected side. In growing patients, this may also restrict ipsilateral growth of the maxilla, although there is normal growth on the unaffected side. In some cases, the growth of the maxilla on the affected side may be normal but that on the unaffected side may be excess, due to uninhibited growth of the normal side. Both these phenomena result in a maxillary cant, though on opposite sides.

In bilateral cases, the mandible is visibly retruded, lacks a chin and the patient presents with an obtuse cervicomental angle. The posterior maxillary height is shortened, giving rise to steep occlusal planes. This convex facial profle or the bird face deformity is also described as the "Andy Gump deformity." Andy Gump was a cartoon character with a very insignifcant chin, who frst appeared in the Chicago Tribune in 1917, created by cartoonist Sidney Smith [6].

Worsened aesthetics of their appearance often becomes a reason for depressive disorders, psychological problems such as stubbornness, low self-esteem, and an inferiority complex.

The longer the duration of hypomobility, the more severe is the muscle atrophy and facial asymmetry. The prognosis for a favorable outcome with treatment is inversely related to the number of years of ankylosis.

#### **65.2.1 Importance of Obstructive Sleep Apnea-Hypopnea Syndrome (OSAHS)**

The presence of retruded mandible and micrognathia in patients with TMJ ankylosis creates narrowing of the pharyngeal airway space (PAS) with mechanical obstruction to respiration, more so in the supine position and during sleep. This process forms a complex syndrome of apneic episodes with signifcant reduction in the mean oxygen saturation levels and secondary cardiac and respiratory problems, known as OSAHS [7]. Therefore, for patients in whom the release of TMJ ankylosis is carried out without the advancement of the mandible for the correction of OSA, there is worsening of an already compromised airway. In such cases wide mouth opening during postoperative jaw exercises can lead to upper airway collapse—a sense of choking, bradycardia, and restlessness or apnea-like episodes, hence increasing chances of ankylosis [8].

#### **65.2.2 Radiographic Features of Bony Ankylosis** (Fig. 65.3)

According to Yan et al. [4], the deformed TMJ is characterized by an enlarged condyle, thickened temporal bone, excessive bone formation, and a radiolucent zone in the bony fusion area. No scattered calcifed dots are found in the radiolucent zone, showing that ossifcation occurs only in the existing bones.

Bony fusion is located in the lateral part of the joint with decreased/absent bone marrow cavity and osteosclerosis. The medial non-bony fusion area shows the atrophic condylar head and rudimentary joint space. Here, the morphology of the bone marrow cavity and bone mineral density is similar to that of normal bone.

Wu et al. [9] demonstrated that in fbrous ankylosis, there is fbrous tissue intruding into the bone marrow of the condyle as well as degeneration of the condylar cartilage. In bony ankylosis, there occurs new bone formation on the rough ankylotic surface of the condyle and slight bone degeneration.

#### **65.3 Classifcations**

Ankylosis has been classifed by various authors according to its extent, site, development, heterotrophic bone formation, symptoms, and most recently, the extent of ankylosis guiding the treatment plan (Table 65.1).

#### **65.4 Preoperative Assessment**

#### **65.4.1 Investigations**

	- (a) Age of onset of ankylosis
	- (b) Type, duration, and extent of ankylosis
	- (c) Type of joint injury or infection
	- (d) Maximal interincisal opening
	- (e) Dental characteristics and occlusion
	- (f) Type of facial deformity
	- (g) Previous surgery
	- (a) Orthopantomogram:
		- (i) Decreased joint space
		- (ii) Absence/presence of normal condylar and coronoid anatomy
		- (iii) Prominent antegonial notch
		- (iv) Markings for osteotomy cuts (for distraction)
	- (b) PA cephalogram:
		- (i) Chin deviation—Cg-ANS-Me (Crista Galli Anterior Nasal Spine - Menton)
		- (ii) Occlusal cant
		- (iii) Grummon's analysis

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 65.3** The computerized tomographic features of TMJ bony ankylosis. The blue circle refers to the bony fusion area located in the lateral part of the joint; in this area, a radiolucent zone can be observed. The red circle refers to the atrophic condylar head and rudimentary joint space located in the medial part of the joint. The green arrow indicates that bone mineral density and morphology of the bone marrow cavity in the non-bony fusion area were normal. The white arrows indicate excessive bone formation around the joint

	- (i) Ramal length: Ar-Go (Articulare-Gonion)
	- (ii) Corpus length: Go-Pog (Gonion-Pogonion)
	- (iii) Pharyngeal airway space (PAS)
	- (iv) N perpendicular to Pog (Nasion perpendicular to Pogonion)
	- (i) Three-dimensional anatomy of bony morphology
	- (ii) Any anatomical measurements as and when required, e.g., size of ankylotic mass, location of ligula, airway space volume, etc.

#### **65.4.2 Airway Implications of TMJ Ankylosis**

#### **65.4.2.1 Assessment**

McNamara's airway analysis on lateral cephalogram helps to assess the PAS, CT provides volumetric assessment of the same, whereas PSG helps to assess the AHI. Moderate to severe AHI may require delayed extubation/tracheostomy.

#### **65.4.2.2 Types of Intubation According to Clinical Situations**

Blind nasal intubation was done historically, but it was traumatic, unpredictable, and unsafe. Tracheostomy is a traumatic experience, but nowadays, awake intubation is performed using midazolam and fentanyl [10]. Fiberopticassisted nasotracheal intubation has become the gold standard for such patients.

However, emergency tracheostomy during/after extubation may be required if:


In these two situations, the mandible may fall back as there is no posterosuperior stop for the ramus and may impinge on the airway, causing further increase in OSA.

#### **65.5 Surgical Anatomy** [11]

#### **65.5.1 Nerve Anatomy** (Figs. 46.6 and 65.5)

#### **65.5.1.1 Facial Nerve**

The main trunk of the facial nerve exits from the skull at the stylomastoid foramen. Approximately 1.3 cm of the facial nerve is visible until it divides into temporofacial and cervicofacial branches.

According to Al-Kayat and Bramley (1979) [12], the distance from the lowest point of the bony external auditory canal (EAC) to this bifurcation measures 1.5–2.8 cm (mean 2.3 cm). The postglenoid tubercle to the bifurcation measures 2.4–3.5 cm (mean 3.0 cm). However, the point at which the upper trunk crosses the zygomatic arch is the most vari-

#### **Table 65.1** Classifcations

#### **I. Topazian (1964)**


#### **II. Sawhney's classifcation (1986)**


#### **III. Turlington and Durr (1993)**

According to heterotopic bone formation within the ankylotic mass


#### **IV. Recent advances: Dongmei He and Colleagues (2011)**

• **Type A1**: Fibrous ankylosis without bony fusion of joint • Ankylosis release temporalis muscle fap, costochondral graft

A2

• **Type A2**: Bony fusion on lateral side of joint, residual condyle bigger than half of condylar head on medial side

#### **Type of Ankylosis Suggested Treatment Plan**


• **Type A3**: Similar to A2 but residual condylar fragment is smaller than half

• **Type A4**: Ankylosis with complete bony fusion of joint

• Resection of ankylotic mass, costochondral graft

• Resection of ankylotic mass, costochondral graft

#### **V. Recent advances: Yan and colleagues (2014)**

Based on its development, ankylosis can be classifed into three phases:


able in terms of distance. It may be anywhere from 8 to 35 mm anterior to the most anterior portion of the bony EAC (mean 2.0 cm). If the superfcial layer of the temporalis fascia and the periosteum over the arch is incised within 8 mm, one can prevent injury to the upper trunk branches.

However, Miloro et al. [13] showed that the average distance anterior to bony EAC was 2.12 cm. (1.68–2.49 cm). His was an MRI-based study as compared to cadaveric dissection-based work of Al-Kayat and Bramley.

The temporal branch of the facial nerve emerges from the parotid gland and crosses the zygoma under the temporoparietal fascia to innervate the frontalis muscle in the forehead. Postsurgical palsy manifests as an inability to raise the eyebrow and ptosis of the brow. Damage to the zygomatic branch results in paralysis to the orbicularis oculi. Nerve damage may necessitate either tarsorrhaphy or gold weight implants into the upper eyelid for gravity-assisted closure. Transcutaneous nerve stimulation may be helpful in cases of neuropraxia.

#### **65.5.1.2 Trigeminal Nerve**

The auriculotemporal nerve courses from the medial side of the posterior neck of the condyle and turns superiorly, running over the zygomatic root of the temporal bone.

**Fig. 65.4** (**a**) Lateral cephalogram, (**b**) PA cephalogram, (**c**) orthopantomogram, (**d**) facial CT scan, (**e**) facial cone beam CT, (**f**) volumetric assessment of pharyngeal airway space on CBCT

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 65.4** (continued)

Preauricular exposure of the TMJ area invariably injures the nerve. Damage is minimized by incision and dissection in close apposition to the cartilaginous portion of the external auditory meatus.

#### **65.5.2 Vascular Anatomy** (Fig. 65.5)

The superfcial temporal artery and internal maxillary artery are the terminal branches of the external carotid artery. In the preauricular approach, the internal maxillary artery runs about 3 mm medial to the mid-sigmoid notch.

The most commonly injured artery during temporomandibular procedures is the middle meningeal branch of the internal maxillary artery. Pogrel [14] in a cadaver study of structures medial to the temporomandibular joint found the middle meningeal artery to be a mean of 31 mm (21–43 mm) medial to the zygomatic arch and a mean of 2.4 mm (2–8 mm) anterior from the height of the glenoid fossa.

#### **65.5.3 Incisions** (Fig. 65.6) [5]

#### **65.5.3.1 Dingman's Preauricular Approach (Refer video on Pre auricular approach in** Chap. 53 and Fig. 53.17**)**

It is the most commonly used incision with many variations. Classically, the incision begins along the course of the helix, just in front of the tragus till the attachment of the ear lobule. Going through the skin and superfcial fascia, about 2 cm above the zygomatic arch, an oblique incision is made through the superfcial layer of temporal fascia. Just above the arch, the periosteum of the zygomatic arch is incised and turned forward as one fap with the outer layer of the temporal fascia, superfcial fascia containing nerves, and skin. The ankylotic mass now stands exposed.

#### **65.5.3.2 Blair (1914)**

It is like the Dingman's incision in preauricular fold, but unlike the former it bends in the region of the zygomatic arch

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 65.5** (**a**) Surgical landmarks for identifying the location of main trunk of the facial nerve and the temporal-facial division during temporomandibular arthroplastic dissection. (**b**) Coronal diagram of the fascial layers and facial nerve at the level of the temporoparietal fascia. (**c**) View from medial aspect of the mandible. Note proximity of middle

meningeal, external maxillary, and masseteric arteries. Care should be taken to protect these structures at the level of the condylar neck and sigmoid notch during osteotomies. (**d**) Relative position of the superfcial temporal artery and vein and the temporal branch of the facial nerve

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 65.6** (**a**) Dingman, (**b**) Blair's inverted hockey stick, (**c**) Thoma's, (**d**) Al-Kayat and Bramley. (**e**) Popowich's modifcation, (**f**) endaural, (**g**) postauricular, (**h**) rhytidectomy, (**i**) retro-auricular limb of rhytidectomy incision

like a hockey stick. The disadvantages include an unsightly scar and possible damage to the frontal branch of the facial nerve.

#### **65.5.3.3 Thoma (1945)**

The vertical limb is in the preauricular fold but angulated at 45**°** in the hairline near the bifurcation of the superfcial temporal vessels.

#### **65.5.3.4 Al-Kayat and Bramley (1979) (refer video on Al Kayat Bramley approach in**  Chap. 53**)**

This reverse question mark cosmetically acceptable incision gives excellent access to the TMJ without causing any damage to important anatomical structures. It starts superiorly through the scalp in the temporal region and extends to the inferior tragus. The superfcial layer of the temporalis fascia is identifed and incised at the root of the arch at 45**°** anterosuperiorly to avoid branches of the facial nerve. A vertical incision may be used if the temporalis fascia or muscle is to be used.

#### **65.5.3.5 Popowich's Modifcation of Al-Kayat and Bramley** [5]

This approach to the zygomatic arch and joint gives excellent visibility with safety. It is longer and wider than the conventional and question mark shaped and begins about a pinna's length away from the ear, anteroposterior just within the hair line, curves backward and downward well posterior to the main branches of the temporal vessels, till it meets the upper attachment of the ear.

#### **65.5.3.6 Endaural** [10]

This was frst described by Rongetti in 1954, with the incision carried in the external ear. The advantages are good aesthetics and excellent access to the TMJ. However, the disadvantages include perichondritis, infection, paresthesia of the pinna, and deformity of the ear.

#### **65.5.3.7 Coronal Extension of Preauricular Incision**

The anterosuperior extension over the scalp of the preauricular incision gives a more aesthetic scar.

#### **65.5.3.8 Rhytidectomy** [10]

The endaural incision is extended in a curvilinear fashion around the mastoid tip, with an S-shaped extension ending in a submandibular incision. This allows access to the entire posterior border of the mandible and allows for identifcation of the main trunk of the facial nerve.

#### **65.5.3.9 Postauricular**

First described by Alexander [15] in 1975, its biggest advantage is that it avoids facial nerve injury and salivary fstula. However, possible complications include stenosis of external auditory canal, infection, and paresthesia of the pinna.

#### **65.6 Treatment Protocol**

Kaban [2] and colleagues described an approach for the treatment of TMJ ankylosis to minimize the incidence of re-ankylosis and produce satisfactory movement of the joint. Their study in 1990 became a landmark management protocol for the management of TMJ ankylosis (Table 65.2).

Yet again in 2009, Kaban [16] considered the potential effect of time and growth (i.e., the fourth dimension) on the outcome of TMJ ankylosis in children and presented another protocol (Table 65.2).

#### **65.6.1 Surgical Options for Ankylosis Release**  (Fig. 65.7a–c)

**History** Ankylosis release surgeries, i.e., various ways of separation of the ramus from the skull have undergone great evolution during the nineteenth century. Esmarch [17] osteotomized the angle to release TMJ ankylosis in 1851. The frst interpositional material was the pterygomasseteric sling, also developed by Esmarch. Condylectomy was frst advocated by Humphrey in 1854. Abbe performed the frst gap arthroplasty in 1880. But it was Topazian in the 1960s [18, 19] who signifed the importance of interpositional grafts for reducing re-ankylosis.

#### **65.6.1.1 Gap Arthroplasty**

The conventional surgical treatment of TMJ ankylosis by gap arthroplasty includes complete resection of the ankylotic

#### **Table 65.2** Kaban's protocols for TMJ ankylosis


#### **2. Kaban's modifed protocol for management of TMJ ankylosis in children (2009)** [16]


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 65.7** (**a**) Gap arthroplasty, (**b**) Lateral arthroplasty (LAP), (**c**) Esmarch's procedure

mass with no soft tissue as an interposition between two cut ends. When a soft tissue is placed between the cut ends, it is known as interpositional arthroplasty. Gap arthroplasty is a relatively simple procedure requiring less operative time; however, it may cause ramal shortening, malocclusion, OSA, and, most distressingly, re-ankylosis. But it may still be used in certain adult patients, where the removal of a small ankylotic mass would not decrease the ramal height signifcantly.

Patients are operated under general anesthesia using a preauricular approach. After the ankylotic mass is exposed, the upper cut is marked, and the lower cut is placed 1.5 cm below it. In cases where normal architecture of the joint is maintained, the lower osteotomy cut is placed from the anterior to the posterior border of ramus just below the sigmoid notch. In cases where normal architecture is not clear, a cut is placed 1.5 cm below the lower border of zygomatic arch. Then the upper cut is completed, and the ankylotic mass is removed. The osteotomy is directed at 45° to prevent fracture of middle cranial fossa. The venous plexus if encountered medially needs only be packed to control bleeding.

A condylar retractor is kept below the ankylotic mass to prevent injury to the internal maxillary artery. Bone is cut initially using a bur/saw/piezoelectric unit through two thirds of its thickness. The remaining one thirds may be removed with an osteotome. A Piezoelectric unit if used, may cut bone till its very end. In case of a larger mass, it may also be removed in pieces. The ipsilateral coronoid process is always resected. Care is always taken to stop the application of Heister's mouth gag intraoperatively just before the opposite condyle dislocates.

In some patients with longstanding ankylosis, the coronoid process of the opposite site becomes hyperplastic. There may also occur fbrosis of the masseter, which would restrict jaw movements further. Thus, not only would the contralateral coronoidectomy be required, but the masseter attachment would also need to be completely dissected off the zygomatic arch. A coronoidotomy may not be adequate, as it may re form and attach again to the temporalis and subsequently cause decrease in mouth opening. An intact disc may not require another soft tissue interpositional graft but may itself be mobilized and repositioned into the new glenoid fossa.

R. F. Elgazzar [20] reviewed 101 patients (109 joints) and, on follow-up, reported that in comparison with other techniques of ankylosis release, gap arthroplasty had the least amount of mouth opening. Interpositional arthroplasty with temporalis gives better results in comparison.

Surgical navigation systems are useful in TMJ ankylosis surgery as they improve both the safety and accuracy of the surgery. The distance from the top of the glenoid fossa to the middle cranial fossa and that from the posterior margin of the fossa to the anterior border of the bony external auditory canal can be monitored via the navigation system. A safety distance of at least 3 mm from the middle cranial fossa and bony external auditory canal should be maintained to avoid injury. It reduces the risks of bleeding and CSF leak [21].

#### **65.6.1.2 Esmarch's Procedure**

This is of historical signifcance only. Esmarch [22] made a small incision posterior to the angle of the mandible and dissected the masseter and medial pterygoid muscles off the bone. A 2.5 cm wide wedge of bone, at the angle of the mandible with apex at upper border and base at the posteroinferior border, was removed. The muscles were then sutured back.

The disadvantage is that since the osteotomy is in the ramus, no ramal osteotomy or distraction can be done for correction of facial deformity. Hence, it is no longer used for ankylosis release.

#### **65.6.1.3 Lateral Arthroplasty (LAP)**

Nitzan hypothesized that in Sawhney's [3] Type II TMJ ankylosis or He's Type A2 [23], if the integrity and location of the displaced condyle and disc can be determined (despite morphological and positional alterations), both could be preserved to fulfll their roles in mandibular growth and function. Only the lateral part of the ankylosed mass was resected. Eight young patients were kept under observation for a period ranging from 6 to 60 months after surgery. She found signifcant improvement in facial symmetry and thereby concluded that the residual condyle retained its own growth potential and helped maintain normal mandibular movement function and occlusion [24].

Yang and Dongmei He evaluated long-term results after LAP in nine growing children and concluded that the residual condyle continues to grow after LAP. This then decreases the amount of further facial asymmetry [25].

### **65.6.2 Arthroplasty with Ramus-Condyle Unit (RCU) Reconstruction** *(Details Covered Under "Hard Tissue Interposition")*

Interpositional arthroplasty with RCU reconstruction is the procedure of choice in recent times. The procedure consists of:


Early postoperative exercises and appropriate physiotherapy are essential to prevent re-ankylosis, adhesions, and soft tissue contracture and to regain normal function of the muscles. Dynamic mouth opening exercise initiated in the immediate postop period by achieving pain control using local infltration of bupivacaine. Dynamic mouth exercises would have to be continued for at least 6 months after surgery.

### **65.7 Soft Tissue Interpositional Materials**  (Video 65.1)

#### **65.7.1 Temporalis Myofascial Flap**  (Fig. 65.8d, e)

Historically, it has been the most commonly used material for interpositional arthroplasty as it is simple in technique and in the vicinity of the original area of surgery. An inferiorly based pedicled composite (fascia and muscle), temporalis myofascial fap is raised supraperiosteally which is fnger shaped and about 5 × 2 cm. The fap is taken either over/ under the zygomatic arch and sutured medially and posteriorly. However, its potential disadvantages include an extended incision, temporal hollowing, increased chances of facial nerve injury, inability to be used again in cases of reankylosis, and myofascial pain secondary to muscle fap compression.

Albert and Merril described the use of a posterior temporalis myofascial fap to prevent a visible anterior fap hollowing [26]. Pogrel and Kaban used an axial patterned temporalis myofascial fap, based on a branch of the middle temporal artery [27].

#### **65.7.2 Dermal Fat Graft** (Fig. 65.8a, b, c)

The abdominal dermal fat graft is harvested from the suprapubic area used an elliptical incision of around 7 × 3 cm. The fat is then de-epithelized to procure a volume of 6–20 ml. About 20–30% excess is taken than the actual requirement. The graft is folded onto itself with the dermis surfaces apposed.

It can be procured quickly and easily with a hidden scar. It is easy to sculpt into the gap after ankylosis release. Minimal heterotopic calcifcation is the advantage of dermal fat graft. However, since this is a non-vascularized graft, it may be prone to resorption.

Dimitroulis presented his study on dermal fat grafts. After a mean follow-up of 41.5 months, only 1 out of the 13 joints reported recurrence of ankylosis [28]. Thangavelu presented a review of eight ankylosed joints treated using full-thickness skin subcutaneous fat grafts and concluded that they were safe and effective [29].

**Fig. 65.8** (**a**) Abdominal fat graft donor site and (**b**) harvested graft, (**c**) abdominal fat graft in place, (**d**) harvested temporalis fap, (**e**) temporalis fap in place, (**f**) maneuver for harvesting buccal fat pad, (**g**) harvested buccal fat pad

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 65.8** (continued)

#### **65.7.3 Buccal Fat Pad Graft (BFP)** (Fig. 65.8f, g)

After the coronoid process is removed, dissection maybe performed along the anterior border of ramus. The main part and temporal extension of buccal fat pad are in close approximation to the coronoid process and tendon of the temporalis. Thus, incising through the periosteum and fascial envelope of BFP at the anterior most edge of the coronoid stump/superior most stump of anterior border of ramus exposes the yellowish buccal pad of fat.

Further blunt dissection is performed to herniate the BFP into the defect with a little teasing and simultaneous milking of maxillary buccal sulcus intraorally near second and third molar region. The main advantage is that its vascularity would maintain the volume of fat for a longer duration with minimal resorption.

Gaba et al. prospectively assessed the fate of BFP following interpositional arthroplasty in 23 joints. In 18 cases, BFP was viable even after 1 year [30]. Refer Chap. 24 for detailed anatomy of the Buccal fat pad.

#### **65.7.4 Amniotic Membrane**

The amniotic membrane, being a natural biologic entity, prevents infammation, reduces scarring, and promotes healing and re-epithelialization. It also has pluripotent, non-antigenic properties. Akhter M. et al. used gamma radiation sterilized and freeze-dried amniotic membranes in 13 patients of TMJ ankylosis and showed that it prevented recurrence of ankylosis [31].

#### **65.7.5 Auricular Cartilage**

Parko in 1973 frst published the use of aural cartilage to replace the meniscus. The biggest advantage of auricular cartilage graft is that it can be harvested from the same surgical feld, remains viable and inert and takes the shape of the glenoid fossa.

However, there are studies that have reported adhesions between the auricular cartilage graft and the condyle, leading to re-ankylosis.

#### **65.8 Hard Tissue Interpositional Materials (RCU Reconstruction)**

#### **65.8.1 Rationale for RCU Reconstruction**

The goal of RCU reconstruction in TMJ ankylosis includes restoration of ramal height. This not only avoids occlusal discrepancies and deviation on mouth opening in unilateral cases but also anterior open bite in bilateral ankylosis. It also provides enough bone stock for future jaw corrective surgeries. The RCU may not contribute as much to facial aesthetics but impacts function greatly. In cases where RCU has not been reconstructed, the jaw deviates laterally when opening the mouth. When closing the mouth, tangential rather than vertical striking occurs on the occlusal surfaces, making mastication diffcult.

Most importantly, in bilateral TMJ ankylosis after gap arthroplasty without RCU reconstruction, there are increased chances of OSA because the ramus falls back due to lack of posterosuperior stop. Also, it may be possible that restoring normal jaw movement and a symmetric mandible will allow future soft and hard tissue development. This would probably lead to decrease in facial asymmetry by giving as near normal anatomy as possible by restoration of growth spurts (Moss's functional matrix theory).

#### **65.8.2 Options, Techniques, Advantages, and Disadvantages**

#### **65.8.2.1 Ankylotic Mass** (Fig. 65.9a)

The ankylotic mass is recontoured and utilized to reconstruct the RCU and thereby restore the mandibular ramal height. All neocondyles after RCU reconstruction are fxed into position with miniplates/screws in the new glenoid fossa just 2 mm short of the soft tissue interpositional material after placing the patient into intermaxillary fxation (IMF).

R. Gunaseelan excised the ankylotic mass, recontoured and reimplanted it, and used it successfully for three cases of condylar reconstruction [32]. However, only if the ankylotic mass is resected as a whole (which poses greater risk to middle meningeal artery) can it be recontoured in an adequate size to reconstruct the RCU, hence the diffculty in routine use.

#### **65.8.2.2 Coronoid Process Graft** (Fig. 65.9b)

Khadka and Hu frst reconstructed RCU using the coronoid process [33]. Reshaped, the coronoid process provides good bone of adequate quality and quantity to reconstruct the RCU. Its membranous origin leads to lesser resorption. Also, a secondary donor site is not utilized. However, as the coronoid is a nonvascular graft, there does exist a very real possibility of its resorption.

Gagan Mehta and Shadab Mohammad conducted a study on 20 cases and reported that there did occur resorption of the coronoid in most of the cases. However, that did not change mandibular function and occlusion [34].

Another method of using the coronoid process is to use it as RCU with its attachment to the temporalis kept intact. Most of the attachment may be stripped of, and only the anterior part of temporalis may be kept attached to the tip of the coronoid. It may cause less resorption as it would be a pedicled graft. Yiming Liu studied 48 patients and compared free vs. pedicled coronoid process grafts and proved that pedicled grafts showed less resorption on prolonged followup [35].

#### **65.8.2.3 Costochondral Graft (CCG)** (Fig. 65.9c)

Poswillo popularized the procedure for using CCG for TMJ ankylosis in 1987. In unilateral cases, CCG may be taken from the ffth rib using a submammary incision. If required on both the sides, alternate ribs, i.e., ffth and seventh, are used [36].

CCG has various benefts including its growth potential, its biological compatibility and the fact that it can remodel to form a new condyle. However, donor site morbidity, resorption or excessive growth on the treated side, and inability to catch up with the speed of growth on the normal side are its potential demerits. Perrott and Kaban [16] described two types of overgrowth—(a) linear overgrowth causing an

#### **Box 65.1 Technical Tip**

To maximize the chances of survival rate of CCG, the following techniques may be followed: meticulous dissection of periosteum and perichondrium, harvesting alternate ribs to prevent pain and pleural tear, retaining intact periosteum and perichondrium at costochondral junction, sectioning the chondral before the osseous part to reduce fracture at the costochondral junction, and only 2–3 mm chondral portion to prevent overgrowth.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 65.9** (**a**) Ankylotic mass, (**b**) coronoid graft, (**c**) costocondral graft

asymmetric or bilateral prognathism and (b) tumor-like overgrowth causing re-ankylosis.

There are various controversies regarding which ribs and how much cartilaginous cap should be taken, how to fx, whether post-op IMF is required or not, and resorption vs. hypertrophy of the graft. Jean Salash reported that out of 72 cases, excessive growth occurred in 54% and equal growth occurred in 38% [37].

Hence, CCG may be used for RCU reconstruction in children less than 8 years of age with facial asymmetry. The justification is that it may help in growth. However, if it overgrows, the overgrowth may be treated like condylar hypertrophy, and the superior 2–3 mm may be cut off.

Children less than 8 years but without facial asymmetry would probably not need a growth impetus, in which cases, a coronoid graft would be suffcient. In children more than 8 years of age, vertical ramus osteotomies may be used to recreate the RCU.

**a**

#### **65.8.2.4 Ramus Osteotomy Pedicled Grafts**  (Fig. 65.10a, b)

Y. Liu [38] used the method of total (Vertical ramus osteotomy—VRO) and partial (L- ramus osteotomy—LRO) sliding osteotomy on the posterior border of the ramus for reconstructing the mandibular condyle in TMJ ankylosis.

The chances of bony resorption and graft failure of the newly reconstructed RCU are greatly reduced as this segment is a pedicled graft with attachment to the medial pterygoid muscle and periosteum and is not a free graft. Hence the height of the ramus is maintained. This also leads to adequate bone stock for further corrective surgeries if and when so required.

For the VRO, the cut is made in a vertical direction starting from the sigmoid notch to the inferior border of the mandible just lateral to the lingula and parallel to the posterior border of the ramus. While retaining an adequate amount of medial pterygoid, the proximal segment is pushed upward to recreate the RCU and plated in the new position. A small triangular chunk of bone just anterior to the osteotomy cut is resected to reshape the lower border and mandibular angle.

For the LRO, an L-shaped cut is made from sigmoid notch parallel to the posterior border of the mandibular ramus, just lateral to the lingula, till 10 mm above the angle of the mandible. The osteotomized segment is shifted upward and fxed with a mini plate creating a gap between the osteotomized segment and remaining mandibular angle. The coronoid process on the affected side is resected, recontoured, and fxed in that gap with another mini plate. The upper part of the ramus is then reshaped like a condyle.

LRO and VRO differ in the residual height of the ramus left after ramal osteotomy. In LRO it is retained, and in VRO it decreases due to the removal of the step at the inferior bor-

c1 d1

**Fig. 65.10** (**a**) V Ramus osteotomy, (**b**) L Ramus osteotomy [38]

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 65.10** (continued)

der. Thus, VRO may be performed in cases where a pronounced antegonial notch is present.

However, these osteotomies cannot be performed in patients less than 8 years because as observed on CBCT, the amount of bone behind the lingula is generally not enough to osteotomize the posterior border of the ramus.

#### **65.8.2.5 Transport Distraction Osteogenesis**  (Fig. 65.11a, b) (Refer Chap. 87)

In multiple operated patients, scar tissue forms with each surgery, which may affect angiogenesis due to limited diffusion. Thus, free autogenous tissue grafts, such as costochondral and coronoid grafts often fail in such cases. Hence, transport distraction osteogenesis is considered as an option for RCU reconstruction, especially in re-ankylosis cases in children. The same L osteotomy cut may be used to fx the distractor.

When RCU reconstruction is performed by transport distraction, it forms a fbrous/pseudo-disc by compressing the connective tissue between the transport segment and the glenoid fossa. This disk decreases the chances of reankylosis [39]. Sharma et al. in 2019 carried out neocondyle distraction in fve patients and reported adequate mouth opening and functional movements in all patients. None of them reported re-ankylosis [40]. But a long-term follow-up study found that the height of these condyles was unstable. Also, these mandibles exhibited some degree of asymmetry [41].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 65.11** (**a**) Transport distraction osteogenesis, (**b**) shows woven bone formation in place of callus in distracted gap, (**c**) alloplastic TMJ replacement with simultaneous release and OGS

#### **65.8.2.6 Alloplastic Total TMJ Replacement (TJR)** (Fig. 65.11c)

The alloplastic joint consists of a fossa component and a ramal component, as a stock or a custom-made prosthesis. Re-ankylotic scar tissue in an adult is best treated by total alloplastic TM joint replacement. Dongmei He and Yi Hui Hu reported that alloplastic TMJ prosthesis is a reliable method to treat recurrent TMJ ankylosis. It may be accompanied by bimaxillary osteotomies for simultaneous correction of secondary ankylotic deformity as well. Its distinct disadvantage is the fact that if used in children, it would need to be replaced [42].

Mercuri et al. [43] specifed the indications of TJR (Box 65.2).

Based on all the above RCU reconstruction options, guidelines are proposed for technique of RCU reconstruction in various clinical situations (Table 65.3).

#### **Box 65.2**




**Table 65.4** Treatment guidelines for different types of ankylotic deformities

#### **Type I (presence of occlusal cant): treatment planning for both maxilla and mandible**


**Type II: (with minimal occlusal cant) treatment planning for mandible alone**


#### **65.9 Facial Deformity Secondary to TMJ Ankylosis**

TMJ ankylosis leads to mandibular deformity of varying magnitude and morphology in the form of decreased ramus and/or body length, deviation of chin, retrognathic/microgenia, bird face deformity, and narrow PAS leading to OSA (refer Fig. 68.18). Hence, establishing a single set treatment protocol for all clinical situations is not possible. Table 65.4 is an attempt to classify and thereby establish treatment guidelines for different types of ankylotic deformities.

*Surgical Techniques and Indications*:

#### **65.9.1 Osteotomies** (Fig. 65.12a–c)

They are indicated for movements of about 6–8 mm. For maxilla, Le Fort osteotomies and, for mandible, sagittal split osteotomy or inverted L ramus osteotomy may be performed.

#### **65.9.1.1 Le Fort I Osteotomy** (Refer Chap. 69)

It allows correction in three dimensions including roll, pitch, and yaw. For vertical maxillary excess, differential maxillary

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 65.12** (**a**) Le Fort I osteotomy, (**b**) sagittal split osteotomy (SSO), (**c**) inverted L ramus osteotomy (ILRO)

impaction may be performed, while for vertical maxillary defciency, maxillary down fracture may be done along with bone grafting. Posterior maxillary height adjustments may also be required.

#### **65.9.1.2 Sagittal Split Osteotomy (SSO)** (Refer Chap. 68)

SSO is useful to differentially settle the occlusion according to the movement of the maxilla, as well as bring the retrognathic mandible forward. The procedure involves three corticotomies—the lingual horizontal, the buccal vertical, and the intermediate cuts. This osteotomy is generally done on the normal side in case of unilateral ankylosis. On the affected side, ramal contour and condylar anatomy distortions, reduced height of the ramus and steep mandibular plane angle make SSO diffcult to perform.

#### **65.9.1.3 Inverted L Ramus Osteotomy (ILRO)**  (Fig. 68.6)

ILRO can be better utilized for increasing the ramal height. This technique is advocated in cases which require signifcant counterclockwise movement to increase projection of the lower third of the face when the ramal anatomy is altered.

The cuts are placed using a submandibular and/or an intraoral approach, posterior and superior to the inferior alveolar canal. A horizontal cut is made above and behind the lingula and then joined to the vertical cut from the inferior border of the mandible.

#### **65.9.1.4 Genioplasty** (Figs. 68.29, 68.32 and 68.34)

Patients indicated for genioplasty have normal ramal height, functional occlusion, defcient or normal pharyngeal airway space, and chin deviation or retrusion up to a maximum of 10 mm, hence minimally deformed cases.

An extended genioplasty is performed with the osteotomy cuts extending up to the frst molar on both sides. Advancement and translational movements in coronal and sagittal planes are carried out. Interpositional or onlay bone grafting may be done so as to achieve further symmetry wherever required.

Alloplastic chin implants made of PTFE, silicon, PEEK, or customized titanium are alternatives to the traditional genioplasty.

#### **65.9.1.5 Orthomorphic Osteotomy**

As opposed to conventional orthognathic surgery, an osteotomy used to restore morphology is termed "orthomorphic correction."

Patients who may undergo orthomorphic osteotomies are the ones having normal ramal height, functional occlusion, defcient or normal posterior airway space, and chin deviation or retrusion up to a maximum of 10 mm, but this can be done only in cases of unilateral ankylosis. Most importantly, the primary indication for this surgery is the presence of soft tissue depression over the mandibular ramus on the unaffected side resulting in a contour defect. The osteotomy cuts are placed on the unaffected side.

Paul Salins [44] designed the osteotomy as an eccentric genioplasty extending from the body to the buccal cortex of the mandible. The cut changes from full thickness from the body to the sagittal buccal cortical cut in the ramus. The segment is then repositioned in such a way that it corrects the midline, the anteroposterior defcit, as well as the lateral morphological contour defects Fig. 65.13a.

#### **65.9.2 Distraction Osteogenesis (DO)**

Traditional bone grafting and orthognathic surgery have disadvantages—bony resorption, necrosis, donor site morbidity, limited advancement, relapse, etc.

Advancement of the mandible using SSO generally is restricted to a maximum of 10–12 mm. In ankylotic patients, the mandible requires much greater movements. Kohn et al. have reported high relapse after SSO [45], especially when used for advancement of mandible. Patients with ankylosis may report higher relapse rate than others. All the above issues may be dealt with DO.

Mandible lengthening with distraction leads to increase in bone stock of the mandible as well as proportionate and harmonious growth of the surrounding soft tissues. This bony regeneration is principally dependent on intramembranous ossifcation. Also healing and mineralization need adequate vascularity. Therefore, the incision to perform the surgery may be kept as limited as possible.

Early distraction may have benefcial effects, on the facial harmony as well as on the TMJ. If the anatomy and thereby function of the soft and hard tissues of craniofacial skeleton is established early in life, it may be possible to regain as near normal growth of the face.

Distraction in TMJ ankylosis patients with obstructive sleep apnea has led to decrease in snoring, daytime somnolence, Apnoea Hypopnoea Index (AHI), and oxygen desaturation episodes. The disadvantage however is that the device may be costly and needs to remain in situ for several months.

#### **65.9.2.1 Simultaneous Maxillomandibular DO**

This technique was frst described by Molina and Monasterio in 1997 [46]. The frst stage of surgery comprises of a Le Fort I osteotomy and a unilateral mandibular osteotomy. The distraction device is fxed to the mandible on the affected site. Under IMF, as the mandible moves forward, the maxilla comes downward, thereby correcting the cant and, simultaneously, the anteroposterior defciency of the mandible. As this whole procedure is done under IMF, occlusion is maintained. The second stage comprises of removal distraction device and an additional genioplasty if required.

This is indicated when the occlusal cant is such that there is vertical maxillary defciency but with presence of functional occlusion. If the mandible alone is distracted, it may lead to occlusal disasters, hence the need to keep the patient under IMF while the distraction is being performed.

#### **65.9.2.2 Orthomorphic DO** (Figs. 65.13a–d, 78.23, 78.24 and 78.25)

As laid down by Manikandan et al. [47] , the concept of orthomorphic distraction of the mandible is a modifcation of Paul Salin's morphometric osteotomy. It involves the distraction of mandibular basal bone to correct the asymmetry in all dimensions, despite a defcient soft tissue capsule. It also provides more movement than that attainable via osteotomy.

The osteotomy design is similar to the one used in conventional orthomorphic surgery. Once the osteotomized segment is mobilized, an internal/external distractor may be placed. Maintenance of the periosteal attachment at the pterygomassetric sling region brings about a pivotal movement at the gonion facilitating the lateralization and advancement of the osteotomized segment. The mechanics of the mandibular asymmetry correction is based on the law of parallelogram of vectors.

#### **65.9.2.3 Genial Distraction**

Distraction of the chin may be performed either in isolation or simultaneously with ankylosis release. A case report on the latter has been published by Gunaseelan et al. [48] in 2007 wherein an extended genioplasty osteotomy was performed and external distractors placed and activated. They suggested that simultaneous genial distraction and arthroplasty may be performed in adults, as the mandible is no longer growing.

This is advocated in adults because they have functional stable occlusion. Therefore, distraction of the basal bone of the mandible without distracting the occlusion bearing segment will only correct the mandibular deformity and the OSAS, but not interfere with the occlusion. However, in children, dental relationships due to mandibular hypoplasia may be very severe and therefore this may not be the treatment of choice. Also, the eruption of the permanent teeth may interfere in osteotomy used in this technique.

Genial distraction is an option to gain larger advancements, although may be limited by an unsightly labiomental fold as advancement increases.

#### **65.9.2.4 Unidirectional DO** (Fig. 65.14a–i)

This procedure is indicated in patients with near normal ramal height but defcient corpus length, chin retrusion and deviation greater than 10 mm, and presence of mild to moderate OSA.

For defcient corpus length, osteotomy cut is placed in the body region, generally between second premolar and frst molar or between frst and second molars. If the patient has not undergone presurgical orthodontics or if distraction is being performed pre-ankylosis release, the cut depends on the distance between the roots of the teeth and presence of impacted teeth. Maria B. Papageorge [49] advised that the cut should be placed in such a manner that the integrity of mandibular angle is maintained as it forms a very important aesthetic component of the face.

According to Samchukov, the vector of distraction should always be parallel to the occlusal plane, regardless of the direction of the osteotomy, to prevent anterior open bite deformity. Kunz et al. [50] has stated it to be a well-known complication of mandibular distraction. Unidirectional distraction is contraindicated in patients exhibiting vertical growth pattern. This is because unidirectional distraction in patients with a steep mandibular plane angle and substantially defcient ramal height may again lead to anterior open bite.

Internal distraction has a defnite edge over external distraction in terms of aesthetics and patient compliance. However, chances of postoperative infection are greater with internal distractors. Also, they have limitations in terms of the amount of distraction possible.

Unidirectional distractors may be placed through either intraoral or extraoral approach. Surgical splints may be prepared on 3D-printed models preoperatively. Upon exposure of the bone, these premarked splints are positioned. Using them as guides, corticotomy sites and sites for distractor pins/screws are marked. Buccal corticotomy and lower border full-thickness cuts are placed. Distractor is fxed and the osteotomy cuts are completed. In case impacted teeth are in the way of the osteotomy cuts, they may be removed intraoperatively itself.

The distractors are activated to check completeness of the cuts and then brought back. Latency period is of 5–7 days, depending on the patient's age. Larger movements require larger periods of consolidation to prevent relapse.

After distracting for around 8–10 days, shape of the regenerate may be changed (callus molding) during the distraction process. Complications may include infection, tooth fracture, change of vector, loosening of pin, anterior open bite, and parotid fstula, but all can be managed conservatively. Callous molding can take care of occlusal discrepancies to a large extent, except that if there is absolutely no overjet. However, with some amount of overjet present, differential distraction may be done on the superior and inferior borders of the mandible. Herein, with the help of callous molding using IMF screws/eyelets and elastics, the inferior border may be distracted more than the superior border.

**Fig. 65.13** (**a, b**) Orthomorphic osteotomy, (**c, d**) orthomorphic distraction

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 65.14** (**a**) Uniplanar distractor fxed on the 3D stereolithographic model with osteotomy cut marked, (**b**) preoperative lateral cephalogram, (**c**) post-distraction lateral cephalogram, (**d**) preoperative frontal

view, (**e**) post-distraction, frontal view (**f**) preoperative lateral view, (**g**) post-distraction lateral view, (**h**) six-month follow-up lateral, (**i**) six month follow-up frontal

Sometimes there may be occlusal locking thereby preventing the distracted regenerate from moving in the direction that is required. A composite block may be prepared on the tooth to frst disocclude it and thereby get distraction in the favorable direction. Later occlusion may be regained by callous molding. The molding of the regenerate substantially reduces the time required for post operative orthodontics.

#### **65.9.2.5 Bidirectional DO** (Fig. 65.15a–g)

Bidirectional distractors are indicated for patients with severely shortened ramal height as well as corpal (body) length, requiring vertical as well as horizontal components of distraction. They are also indicated in cases with increased mandibular plane angle as well as for patients with moderate to severe OSA.

Surgical splints are prepared on 3D-printed models. Upon exposure of bone through a submandibular incision, two osteotomy cuts are placed on either side. One osteotomy cut is placed on the ramus and the other in the body region on either side of the angle, keeping the intermediate segment between 2.5 and 3 cm to avoid avascular necrosis. The device is secured to the mandible with six percutaneous pins (Schantz' pins)—one pair each at the ramus, angle, and corpus. The same procedure may be used for internal distractors as well.

The osteotomy site depends on position of teeth, lingula, mental foramen, and size of the intermediate segment. Vector of horizontal distraction should be parallel to occlusal plane, and vector of vertical distraction should be parallel to posterior border of ramus. In bilateral cases, horizontal and vertical components of either side should be parallel to each other. A 2–3 mm overcorrection is generally advisable. Callous molding may be used for occlusal adjustments. A single osteotomy cut may however be used for 3D or multivector distractors, thereby considerably reducing the surgical diffculty as well as the intraoperative time. Their main drawback is their prohibitive cost.

#### **65.9.2.6 Impact of Mandibular DO on OSA**

The ankylotic retruded mandible has an ineffcient genial muscular apparatus as well, thereby causing retroglossal airway obstruction, therefore, OSAS. Mandibular advancement

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 65.15** (**a**) Biplanar distractor fxed on the 3D stereolithographic model with osteotomy cuts marked, (**b**) preoperative lateral cephalogram, (**c**) post-distraction lateral cephalogram (marked increase in PAS can be appreciated) (**d**) preoperative frontal view, (**e**) post-distraction frontal view, (**f**) preoperative lateral view, (**g**) post-distraction lateral view

in such cases has shown 97% success in pediatric and 100% success in adult patients. Decrease in OSAS may be evaluated by an AHI less than 50% decrease in the AHI with a near normal peripheral oxygen saturation.

#### **65.10 Sequence of Release and Deformity Correction**

OSA, in terms of AHI and PAS, is the principal factor that determines the sequence of release and deformity correction, i.e., whether to release frst or distract frst (refer Chap. 71 on OSAS and Figs. 71.8, 71.9, 71.10, 71.11, 71.12, 71.13 and 71.14).

#### *Single-Stage vs. Multistage Procedure:*

Treatment protocols can generally be categorized into singlestage or multistage treatments. Single-stage treatments institute ankylosis release and correction of secondary deformities (in the form of maxillary and mandibular osteotomies or distraction) all together. In the multistage protocol, ankylosis is released, and deformities are corrected in different stages.

#### **65.10.1 Multistage Surgical Treatment**

Severe secondary deformities are candidates for multistage procedures as a single-stage surgery may cause severe malocclusion. Correction of the same would require unrealistic amount of tooth movement.

Advantages: The multistage protocol is generally better for patients with signifcant medical comorbidity. This is so because a single-stage procedure obviously demands greater surgical time, thereby increasing the intraoperative risks. Multistage procedures facilitate early postoperative physiotherapy and, thus, a more stable postsurgical outcome. Also, the relapse monitoring is easier.

Disadvantages: Multiple surgeries, increased cost, and patient compliance issues

#### **65.10.1.1 Multistage with Ankylosis Release First**

According to López et al. [51], mandibular distraction should be performed after ankylosis release, as only then would be complete growth potential of the mandible be known. Releasing the ankylosis frst would ensure adequate food intake, preparing the patients for subsequent, more complex surgeries. Also, surgeons could then formulate customized treatment plans based on individual clinical requirements and thereby provide more accurate correction of the deformity.

#### **65.10.1.2 Multistage with Distraction First**

Some surgeons recommend that distraction may be frst used to restore the length and projection of the mandible. Later arthroplasty may be followed by orthognathic surgery to obtain mouth opening and settle the occlusion.

Advantages: The mandibular bone defciency and the airway volume are both increased simultaneously. The subsequent intubation is much safer. Secondly, for patients with OSA, this treatment sequence reduces the incidence of postoperative airway issues—if ankylosis is released frst, as the mandible falls back specially in bilateral cases, the already reduced airway space then gets further reduced, requiring reintubation or emergency tracheostomy. This incident can be avoided if distraction proceeds release.

#### **65.10.2 Single-Stage Surgical Treatment**

Patients with mild to moderate dental and skeletal deformities are ideal candidates for single-stage procedures. The minimal malocclusion may be treated by orthodontics alone. In these such cases, ankylosis release along with facial aesthetic surgeries which do not involve the occlusion may be performed, e.g., genioplasty, mandibular recontouring, and alloplastic implants.

Advantages: This corrects the restricted mouth opening as well as the secondary deformity simultaneously and avoids further surgeries. It provides low cost, immediate satisfaction, particularly in patients with psychological issues, and mild OSA.

Disadvantages: Maxillomandibular fxation often required after orthognathic surgery interferes with postoperative mouth opening exercises and therefore increases the chances of re-ankylosis. In case of internal distraction devices, there still arises the need for a second surgery to remove it. Also, the effect of distraction may be unsatisfactory because of the unstable condyle—if the osteotomy is placed in the ramus, the proximal segment may go up into the gap created after ankylotic mass removal, cause loss of vector and thereby re-ankylosis. Thus, to prevent this complication, while performing concomitant release and distraction, osteotomy cut may be placed only anterior to the angle, in the body region.

Another potential complication is the interference between physical exercises and distraction. A pseudo-joint may be formed in the callus area when the patient exercises, with the mouth opening force being directed toward the callus instead of the newly released joint. To prevent this complication, intensive active mouth opening exercise with wooden sticks/ heisters may be started from postoperative day 1 itself. Mouth opening exercise from day 7 onward, i.e., once distraction is started, should exclude the use of the above.

#### **65.10.2.1 Single-Stage Release with Orthognathic Surgery (OGS)**

As mentioned earlier, in patients that exhibit mild dental and skeletal deformities, aesthetic surgeries not involving the tooth-bearing segments may be performed.

For the patients with moderate skeletal deformities, SSO along with ILRO and bone grafts may be used to lengthen the affected ramus. If necessary, Le Fort I osteotomy may be used to correct the occlusal cant in unilateral cases or bring the posterior maxilla down in bilateral cases.

Songsong Zhu [52] performed a study on 27 adult patients who underwent simultaneous ankylosis release and correction of secondary deformity as a single surgery. No relapse occurred.

Yi Hui Hu [42] studied 11 patients where CAD/CAM technique was utilized as a guide to determine level of removal of ankylotic mass and placement of TMJ prosthesis. Simultaneous Le Fort I osteotomy was performed in two patients guided by digital templates. Results showed that alloplastic TMJ prosthesis is a reliable treatment for recurrent ankylosis. The CAD/CAM technique produces accurate therefore stable results.

Many cases would require a custom-made prosthesis, typically fabricated with a stereolithographic model. Ryu et al. in 2016 reported a case where bilateral TM joints were replaced with a custom-made TMJ prosthesis. Virtual surgical planning (VSP) and STL model simulation helped in placing the mandible in a new improved occlusal and aesthetic profle [53]. This has become a routine procedure now in adult patients, i.e., custom-made joints based on VSP along with simultaneous OGS.

#### **65.10.2.2 Single-Stage Release with DO**

Simultaneous interpositional arthroplasty with DO for TMJ ankylosis, apart from increasing the length of the mandible, leads to the correction of gross facial asymmetry and midline shift and provides space for eruption of hitherto unerupted teeth. It helps reduce treatment time and need for an additional surgery and also alleviates the need for second tracheostomy, if the fberoptic intubation is not possible.

Only unidirectional distraction in the mandibular body (in patients with AHI 15–30) may be performed along with release. If bidirectional distraction is performed, after placing the arthroplasty cuts, if two more cuts are placed in the body and the ramus, there are increased chances of avascular necrosis of the segments. Thus, bidirectional distraction may not be performed along with release; it may be performed either pre- or post-release, unless a 3D distractor is being used.

Krishna Rao et al. [54] performed a study on six patients and concluded that simultaneous release with DO should be used to correct ankylosis with facial asymmetry and reported satisfactory cosmetic correction of deformities**.** Girish B Giraddi et al. [55] performed a similar study with nine cases and concluded that it not only corrects the facial deformity but also saves the trauma of a second diffcult intubation**.**

Lopez and Dogliotti [51] in 2004 asked a pertinent question—"Is it reasonable to perform ankylosis release and mandibular distraction simultaneously without knowing which patients will be able to experience growth with time? In that case it would be necessary to predict growth to apply the exact amount of mandibular distraction for obtaining stable results." This question can now be answered—in children, the only indications for simultaneous release with distraction would be moderate to severe OSA, with AHI 15–30 (however with normal ramal height) and extreme facial deformity causing issues with the child's psyche.

#### **65.10.2.3 Single-Stage Release with Genioplasty**

Most literature till date has either been looking at ankylosis in isolation from facial asymmetry and has been dealing with only ankylosis release or facial deformity as staged events or has been looking at correcting one of the biggest facial deformities, all at one go. There is no middle path mentioned in literature wherein ankylosis and a substantial part of its related deformities can be corrected without the following problems a supra-major surgery under general anesthesia, extremely expensive 3D-printed splints and alloplastic joint replacements, expensive and protracted orthodontics requiring multiple hospital visits from the underprivileged, undernourished patients living in far-fung areas, and long-term patient noncompliance for distraction. Also, if osteotomies are performed before the TMJ attains stability, surgical outcome may be less than satisfactory as related to aesthetics and occlusion.

A suggested solution for the above problem in adults with mild to moderate OSA is a single-stage surgery—ankylosis release by interpositional arthroplasty simultaneously with genioplasty. It would provide a one-step solution to restoration of function and reasonable aesthetics within a reasonable amount of general anesthesia time, no occlusal discrepancies, no compliance for distraction, and no need for orthodontics. Most importantly, it would not interfere with any other secondary corrective procedure later, if the patient so desires.

The author has conducted a study on 43 ankylosed joints & set forth single-staged treatment guidelines ankylosis release, RCU reconstruction, and extended advancement centering genioplasty for increase in mouth opening, restoration of ramal height, and improvement in facial asymmetry as well as OSA. Average mouth opening at maximum follow-up of 20 months was 34.36 mm with no reported recurrence. Average increase in N perpendicular to Pog was 7.16 mm, average decrease in neck-chin angle and labiomental angle was 31.6° and 35.4°; respectively, average increase in PAS was 2.92 mm. Average 50% improvement of AHI was seen in all 18 patients who had OSA [56].

#### **65.11 Guidelines for sequencing of release and deformity correction**

	- Children
		- Release frst

Simultaneous release and unidirectional distraction

	- Release frst

Simultaneous release with/without joint replacement and osteotomies


– Short ramus (requiring bidirectional distraction) Children and adults: distract frst

	- Joint replacement with osteotomies
	- Simultaneous release with distraction

#### **65.11.2 In Released Patients: To Decide Regarding Type of DO**


#### **65.12 Unfavorable Results in TMJ Ankylosis Surgery** (Table 65.6)

#### **Table 65.6** ■


**2. Issues related to secondary surgery of deformities**


#### **Table 65.5** Relation of Apnea-hypoapnea index with PAS


#### **65.13 Conclusion**

• Traditionally, TMJ ankylosis and its associated micrognathia have been treated in multiple stages. Rehabilitation of mandibular function, prevention of re-ankylosis, and promotion of mandibular growth have been the main aims of treatment. The treatment has now advanced from only ankylosis release to total joint replacement as well as facial deformity correction, all simultaneously as far as possible.


**Acknowledgment** I wish to convey my deepest thanks and sincerest gratitude to my resident Dr. Hrushikesh Gosai, without whose observations, comments, and technical expertise this manuscript would have not been possible. A mere word of thanks is not suffcient to express the unfinching support and inestimable aid of my staff Dr. Jigar, Dr. Utsav, and Dr. Bipin and my residents Dr. Hiral, Dr. Philip and Dr. Nisha during the preparation of this chapter. I would be failing in my duty if I did not recognize the contribution of my biggest teacher in TMJ ankylosis, my Ex-Hod Dr. Babu Parmar.

**Disclosure** Authors have no fnancial conficts to disclose

#### **65.14 Case Scenarios**

#### **Case 1** (Fig. 65.16a–h)

A 23-year-old male patient presented with unilateral rightsided bony ankylosis with retruded and deviated chin with body and ramal length near normal. So, the patient was planned for advancement centering genioplasty and onlay bone graft along with TMJ ankylosis release.

#### **Case 2** (Fig. 65.17a–f)

A 14-year-old male patient presented with facial asymmetry secondary to TMJ ankylosis with moderate OSA. Cephalometric analysis revealed defciencies in the length of the mandibular ramus and corpus of the right side and the corpus alone on the left side. So, he was planned for biplanar distraction on right side and uniplanar distraction on left side.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 65.16 (a–h)** Case 1 Right side TMJ ankylosis (**a**) Preoperative frontal view, (**b**) preoperative lateral view, (**c**) preoperative mouth opening, (**d**) postoperative frontal view, (**e**) postoperative lateral view, (**f**) postoperative mouth opening, (**g**) preoperative orthopantomogram, (**h**) postoperative orthopantomogram (note the genioplasty and onlay bone graft fxations)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 65.17** Case 2 (**a**) Preoperative frontal view, (**b**) preoperative lateral view, (**c**) postoperative frontal view, (**d**) postoperative lateral view, (**e**) Pre-distraction PA cephalogram, showing implant on the right side from the earlier surgery for interposition arthroplasty, (**f**) postoperative PA cephalogram

#### **References**


Cascarini L, editors. Maxillofacial surgery. 3rd ed. Edinburgh: Churchill Livingstone; 2017.


mandibular deformity in children. J Craniomaxillofac Surg. 2004;5182:38–42.


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**Part XVIII**

**Orthognathic Surgery**

## **Diagnosis and Planning in Orthognathic Surgery**

**66**

Johan P. Reyneke and Carlo Ferretti

### **66.1 Introduction**

Over the last four decades, the scientifc foundations for the art of changing facial appearance and improving orofacial function through orthognathic surgery were laid, and the value of treatment to improve lives is undisputed. The main treatment objective is currently not limited to achieving short-term improved occlusal function but also enhanced facial aesthetics and an open airway. Orthognathic surgery requires the combined skills of the specialities of orthodontics and oral and maxillofacial surgery; however, there remain major limitations relating to the uneven geographical distribution of experienced dedicated clinicians and fnancial barriers to the correction of dentofacial deformities. The treatment of some malocclusions combined with mild skeletal disharmony is possible by orthodontic compensation of the dentition with compromised facial aesthetics. Borderline cases therefore require meticulous assessment before fnally deciding on orthodontic treatment alone or a combination of orthodontics and surgery as treatment approach.

Most compromised treatments lead to suboptimal results such as:


J. P. Reyneke (\*)

Department of Oral and Maxillofacial Surgery, Faculty of Health Sciences, University of the Western Cape, Cape Town, South Africa

Department of Oral and Maxillofacial Surgery, University of Oklahoma, Oklahoma City, OK, USA e-mail: johanrey@worldonline.co.za

C. Ferretti

Department of Maxillofacial and Oral Surgery, University of Pretoria, Pretoria, South Africa

Private practice, Johannesburg, South Africa


Which treatment plan to adopt should be discussed with the patient (and perhaps the parents or spouse) and all the advantages and disadvantages of each approach explained. The decision may also be infuenced by factors such as the orthodontist's experience, fnancial insurance cover, available surgical expertise, and the patient's attitude and preferences [1].

Patients with dentofacial deformities are treated with four prime goals in mind:


© The Association of Oral and Maxillofacial Surgeons of India 2021 1437

Director of The Center for Orthognathic Surgery, Mediclinic, Cape Town, South Africa

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_66

these soft tissues will contribute greatly to the development of sleep apnea especially as soft tissue laxity develops with aging. This consideration may infuence treatment decisions particularly in Class III malocclusion. For example, we may be loath to unduly setback a mandible in a young adult due the future potential for sleep apnea development. Thus, in double jaw surgery, a treatment plan that favors greater maxillary advancement or in a single jaw surgery case a maxillary advancement may be preferable to a mandibular setback. These considerations add a further layer of complexity to the treatment algorithm as airway considerations may mean a compromise of aesthetics and vice versa [2, 3].

#### **66.2 Systematic Aesthetic Facial Evaluation**

The clinical assessment of the face is the most valuable of all diagnostic procedures and should be performed in a systematic fashion. The facial examination should start at the frst instant a clinician meets the patient and continues during the initial informal discussion. During this period the patient is not self-aware, and facial function and features will be at their most natural. The focused facial examination follows and should be done while the patient is seated comfortably in natural head posture, the teeth in centric occlusion and the lips relaxed. The goal of the facial examination is to determine what components of the face are detracting from facial harmony and what functional problems may accompany the malocclusion and to make a tentative diagnosis.

It is helpful to structure the facial examination into frontal and profle views [4].

#### **66.2.1 Frontal View**

Facial appearance when viewed from the front is, not surprisingly, what a patient will value most.

A helpful frst step is to assess the facial form.

• Facial form (Fig. 66.1a–h)—The relationship between the facial width and height has a strong infuence on facial harmony. The ratio of facial width to facial height is more important than absolute values in establishing the overall facial type. Attractive faces tend to have proportions that fall within normative values. When evaluating facial form, the overall body build of the individual (corporo-facial relationship) should be considered (i.e., short and stocky versus long and thin). The height-to-width proportion (trichion to menton: bizygomatic width) is 1.3:1 for females and 1.35:1 for males. The bigonial width should be approximately 30% less than the bizygomatic dimension, and the width and shape of the chin should form a harmonious part of the overall facial contour. Leptoprosopic faces (long and narrow) are often associated with vertical maxillary excess, a narrow nose, mandibular anteroposterior defciency, narrow gonial angles, microgenia, a high palatal vault, and an anterior open bite (Fig. 66.1a–c), while dolichoprosopic faces (short and square) are often associated with vertical maxillary defciency, masseter hyperplasia, wide gonial angles, macrogenia, and Class III deep bite malocclusions (Fig. 66.1d, e). Individuals from Asia often have round oval faces (Fig. 66.1f). Patients with mandibular defciency often have a tapered facial lower facial third and microgenia (Fig. 66.1g, h).

	- *Outer ffths:* Is measured from the lateral helix of the ear to the lateral canthus and is an indication of the width of the ears. Bat ears can be camoufaged by an appropriate hairstyle; however, otoplastic surgical procedures are relatively atraumatic and can improve the facial appearance dramatically. Otoplasty can be performed at the same time as orthognathic procedures.
	- *Medial ffths:* Are measured from the outer to the inner canthus of the eyes. The outer border should coincide with the gonial angles of the mandible. In patients with long and narrow faces, the gonial angles will fall medial to this line, while in patients with broad and square faces, the gonial angles will fall lateral to these lines. Within these ffths it should be noted that the distance between the inner margins of the irides of the eyes should be equal to the width of the mouth. Abnormal interpupillary and intercanthal distance are often observed in syndromic patients and can only be altered by means of craniofacial surgery.
	- *Middle ffth:* Is demarcated by the lines through the inner canthus of the eyes. In patients with hypertelorism, this ffth would be relatively larger than the others. The ala of the nose (alar base width) should coincide with these lines, while the nasal dorsum

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 66.1** The relationship between the facial height and width infuences facial harmony. The variations of facial form: (**a**) narrow, (**b**) long, (**c**) tapered, (**d**) square, (**e**) round, (**f**) oval, (**g**) sharp, and (**h**) pointed, are demonstrated

should be approximately half of the intercanthal distance. For patients in whom maxillary advancement and/or superior repositioning is planned, this measurement should be considered and surgical control of the alar base may be indicated.

	- *Upper third:* Deformities in this third can fortunately often be masked by an appropriate hairstyle; however,

it is important to record deformities in this area as they may indicate craniofacial syndromes.

– *Middle third:* Generally, no sclera is seen above and below the iris in a relaxed eyelid position. Individuals with midface defciency tend to show sclera under the iris of the eye and will tend to have a long narrow nose. The cheekbone-nasal base-upper lip-lower lip contour line is a convenient indicator of the harmony of the structures of the midface (zygoma, maxilla, and nasal base) with the paranasal area and upper lip. This imaginary line starts just anterior to the ear, extends anteriorly across the cheekbone, and then curves antero-inferior over the maxilla adjacent to the alar base of the nose, ending lateral and slightly below the commissure of the mouth. The line should form a smooth, continuous curve (Fig. 66.4a, c). A skeletal deformity will cause an interruption of the curve, and

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 66.2** Transverse facial proportions

the area of interruption in the line is often an indication of a specifc underlying deformity (Fig. 66.4b).

– *Lower third:* (Fig. 66.3) The middle to lower third vertical height of the face should have a 5:6 ratio. In the well-balanced lower third of the face, the upper lip makes up one third, while the lower lip and chin composes the lower two thirds. Normal upper lip length is 20 ± 2 mm for females and 22 ± 2 mm for males and measured from subnasale to upper lip sto-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 66.3** Vertical facial proportions

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 66.4** (**a**) Cheekbone-nasal base-lip contour. (**b**) The interruption of the curve at MxP (maxillary plane) indicates maxillary anteroposterior defciency. (**c**) Correction of the malocclusion establishes a smooth contour line

mion (stomion superius). When the upper lip is relatively short, there will be a tendency to an increased interlabial gap and excessive upper incisor exposure with normal facial height. This should not be confused with the same observations in patients with vertical maxillary excess (Fig. 66.8). Normal lower lip length is 40 ± 2 mm for females and 44 ± 2 mm for males. The lower lip may give the false impression of being short due to a deep bite. It is mandatory that the interlabial gap and tooth exposure be evaluated with the teeth in occlusion and the lips in repose (Fig. 66.8b). A gummy smile is not a defnite indication of vertical maxillary excess as some patients may have a normal maxillary height but hyperactive upper lip when smiling. An increased interlabial gap (more than 3 mm), excessive upper incisor exposure (more than 4mm), and a gummy smile are typical characteristics of vertical maxillary excess (Fig. 66.9). For patients in whom the upper incisors are not visible under the upper lip, the tooth lip relationship should be evaluated with the mandible rotated open until the lips just separate (Fig. 66.8a). Lack of upper incisor exposure is indicative of vertical maxillary defciency and usually occurs in combination with decreased lower facial height. The height of the lower face can also be infuenced by the height of the mandible, and the height of the chin should be noted in any discrepancy in vertical facial height.

The arbitrary subdivision of the face into vertical thirds has a critical faw. The effects of a deformity of one jaw and the correction thereof may stretch across two conventional facial thirds.

*It is for this reason that the authors believe a more pragmatic approach to facial aesthetic assessment is to divide the face into zones of infuence, i.e., zones which can be modifed by orthodontics and orthognathic surgery.*

The *Ferretti-Reyneke analysis* (Fig. 66.5) divides the face into fve zones of infuence, i.e., zones of soft tissue facial integument that are under the infuence of the corresponding underlying skeleton:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 66.5** The *Ferretti-Reyneke* analysis

• *The gnathic complex.* This subunit is subdivided into an upper *maxillary component* (iii) which extends from the lower aspect of the oculonasal complex to a curved line extending along the lower margin of the upper lip (or the incisal edge of exposed maxillary teeth) to the angle of the mouth and proceeding in a curvilinear fashion to the lower attachment of the auricle and a lower *mandibular component* (iv) which extends to the lower border of the mandible and contains in its anterior aspect the oval *mental subunit* (v) which delimits the soft tissue chin.

It is critical to remember that facial evaluation is not the search for deviation from the norm of a single subunit but the search for proportion. For example, a facial form diagnosed as vertically excessive means it is excessive in relation to its transverse dimension, *not* that it is longer than the norm. By increasing only the transverse or only the vertical dimension, facial harmony will be lost; however, harmony is reestablished by increasing both the transverse and vertical dimensions.

#### **Facial Symmetry**

The facial midline is the reference line to evaluate the forehead (glabella), nasal dorsum, nasal tip, maxillary dental midline, columella of the nose, philtrum of the upper lip, mandibular dental midline, lower lip, and the chin (Figs. 66.2 and 66.6). In the initial overall assessment of facial asymmetry, we should establish whether the asymmetry involves the chin, the mandible or the maxilla, or a combination of the structures. Careful assessment of an occlusal cant of the maxilla is mandatory as it will play an important role in the correction of the asymmetry. Soft tissue asymmetry, either primary or secondary to skeletal asymmetry, should be noted. Finally, symmetry of the nose, orbits, and forehead should be evaluated (Figs. 66.2 and 66.6).

The face is a three-dimensional structure, and the symmetry of the face will be infuenced by deformities in the vertical, anteroposterior, and transverse planes. Clinical frontal assessment of the face is however the most critical, and discrepancies should be correlated with posterior facial asymmetry by noting any transverse, anteroposterior, and/or sagittal cants in the occlusal plane. The occlusal plane should be parallel to the interpupillary line, provided there is no orbital dystopia. Surgical correction of an occlusal plane cant often corrects facial asymmetry, and the severity of the cant should correlate with the dental and facial asymmetry. During treatment planning the clinicians should assess if orthodontic

©Association of Oral and Maxillofacial Surgeons of India

or surgical correction of dental midlines is required. With skeletal asymmetry the dental midline should not be orthodontically coordinated but rather aligned in the center of each jaw to allow surgical correction of the skeletal asymmetry. Keep in mind that no face is perfectly symmetric.

#### **Lips**

The lips play an extremely important role in the overall facial aesthetics, and careful assessment is required. Lip symmetry should be evaluated in the rest position as well as when the patient is smiling. Lip symmetry may be infuenced by facial nerve dysfunction, underlying dentoskeletal deformities, scarring due to previous trauma, congenital clefting, microstomia, macrostomia, or hyperplasia. The lower lip generally exhibits 25% more vermillion than the upper lip. With the presence of an accentuated Cupid's bow, only the upper incisor may be visible under the upper lip and very little or even no lateral incisor (Fig. 66.7). An interlabial gap of 0 to 4mm and 1 to 4mm of upper incisor tooth exposure under the upper lip with the lips in repose are considered pleasing while the full crown of the incisor exposed when smiling.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 66.7** An increased interlabial gap with excessive amount of upper incisor exposure under the upper lip (**a**). A poorly shaped upper lip (distorted Cupid's bow) and excessive amount of vermillion excessive exposure (**b**)

Note any asymmetry of the lips when smiling (Fig. 66.10). When vertical skeletal or dental corrections are contemplated, the vertical relationship of all four incisors to the upper lip should be clinically considered. Only the upper central incisors are visible on a lateral cephalometric radiograph and should not be used to plan vertical maxillary changes (c in Fig. 66.13).

#### **66.2.2 Profle View**

Although it is emphasized that the clinical assessment of the face is mandatory, the cephalometric analysis of the lateral cephalometric radiograph has been the predominant method of profle evaluation. Many orthodontists are accustomed to using the quantitative data obtained from the lateral cephalometric analysis as the main diagnostic tool. The contemporary orthodontist and facial surgeon rely on facial proportionality and more subjective aesthetic evaluation criteria than linear and angular measurements. Treatment decisions should rather be made by what is most aesthetically appealing rather than by what the cephalometric norms indicate. The plethora of cephalometric values available can lead to confusion and unnecessary complexity. The undermentioned cephalometric measurements are the most useful indicators to confrm a clinical diagnosis.

#### **Nasolabial Angle (a in Fig. 66.11)**

The angle is measured between the columella of the nose and the upper lip and should be between 85° and 105°. It is infuenced by the position and angle of the upper incisor teeth and the anatomy of the nasal columella. Excessive orthodontic retraction of the upper incisor teeth (i.e., com-

**<sup>a</sup> <sup>b</sup>**

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 66.8** No upper incisor exposure under the upper lip leads to a "toothless" look (**a**). An increased interlabial gap with excessive upper incisor exposure suggests vertical maxillary excess (**b**). The assessment should always be done with the lips in repose

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 66.9** A patient with vertical maxillary excess. Note the increased interlabial gap with the lips in repose (**a**) and gummy smile (**b**)

promised treatment for a Class II occlusion) will lead to poor upper lip support and an increased nasolabial angle. This will often lead to early wrinkling and an aging appearance of the lip. An over-closed bite will cause an acute angle, while a hanging columella of the nose will increase the angle.

#### **Labiomental Angle (b in Fig. 66.11)**

This angle is formed by the intersection of the lower lip and chin measured at the soft tissue of the chin. The angle is a gentle curve and should be 120° ± 10°. The lower lip, the depth of the labiomental fold, and chin button should form a smooth and harmonious S-shaped curve with the labiomental fold dividing the chin into an upper third and lower two thirds. The angle is acute in patients with Class II dentoskeletal deformities due to the everted lower lip or patients with macrogenia. Individuals with Class III dentoskeletal deformities and the lower incisors retroclined (compensated) or patients with microgenia will exhibit an obtuse labiomental angle.

#### **Lip-Chin-Throat Angle ((i) in Fig. 66.12)**

The angle is formed between the lower border of the chin and a line connecting the lower lip and soft tissue pogonion. The chin and submental area are considered attractive with an angle between 100° and 120°.

©Association of Oral and Maxillofacial Surgeons of India

#### **Chin-Throat Length ((ii) in Fig. 66.12)**

It is measured from the angle of the throat to the soft tissue menton. It is only meaningful when this angle is measured with the patient's head in natural posture. A length of between 38 and 48mm is considered to be normal and is signifcant when assessing mandibular length. This measurement is helpful for differentiating between mandibular anteroposterior excess and maxillary anteroposterior defciency. For a patient with a Class III malocclusion and normal chin-throat length, maxillary defciency should be suspected.

**Fig. 66.10** An asymmetric smile ©Association of Oral and Maxillofacial Surgeons of India

**Fig. 66.11** (a) The nasolabial angle, measured between the inclination of the columella of the nose and the upper lip, should be 85°–105°. (b) Labiomental fold. The lower lip-chin angle should be 130°. However the general shape of the chin should be considered

#### **Upper Lip Length (b in Fig. 66.13)**

The length of the upper lip is measured from subnasale to the lower border of the upper lip (stomion superius) and should be 18–22 mm in females and 20–24 mm in males. This measurement should be performed with the lips in repose. During the planning of tooth-lip relationship, it should be kept in mind that the upper lip will increase in length with age.

#### **Interlabial gap (d in Fig. 66.13)**

The interlabial gap should be assessed with the lips in repose and the teeth in occlusion. It is measured between stomion superius and stomion inferius (0–4 mm). If the lips touch when the teeth are in occlusion, the upper incisor-lip relationship should be evaluated with the lower jaw rotated open until the lips are slightly apart.

#### **Facial Contour Angle (e in Fig. 66.13)**

This measurement will give the clinician an indication of facial convexity or concavity and is infuenced by the anteroposterior relationship between glabella, subnasale, and menton. The angle is formed between the upper facial plane (glabella-subnasale) and lower facial plane (subnasale-pogonion). The angle is recorded above subnasale and expressed as negative when the angle is ahead of the upper facial plane (in convex profles) and as positive when the angle is behind the upper facial plane (usually in concave profles). A pleasing facial profle for females will have a facial contour angle of −13° ± 4° and for males −11° ± 4°. This measurement will also be infuenced by the height of the maxilla. The mandible will rotate counterclockwise (upward and forward) with vertical maxillary defciency leading to a more concave profle, while it will rotate clockwise (downward and backward) with vertical maxillary excess leading to a more convex profle.

#### **Nose (Fig. 66.14)**

This important anatomic structure is situated in the middle of the face, and its important infuence on facial aesthetics has often been neglected by orthodontists and maxillofacial surgeons in the past. More focus is placed on the aesthetic evaluation of the nose by the fact that the relative nasal aesthetics can be infuenced by orthodontic treatment and certainly by orthognathic surgery. The fact that rhinoplasty is now considered to be part of the feld of treatment for many orthognathic surgeons has certainly made the careful aesthetic evaluation of the nose an important consideration. In many cases nasal reconstruction will form part of the orthognathic treatment plan, and in some cases, reconstruction can be performed concurrently with orthognathic surgery. The authors prefer to defer most nasal reconstructions to 6 months after orthognathic surgery due to the substantial relative effects orthognathic surgery has on nasal aesthetic.

The amount of nostril show in profle view may be affected by either a hanging columella or retracted alae (Fig. 66.14a). The shape of the dorsum should be noted as normal, convex, or concave. It is important to distinguish between a large dorsum and a turned-down nasal tip as the treatment would be entirely different. The relationship between the lengths of the nasal dorsum and the projection

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**Fig. 66.12** The lip-chin-throat angle (i). Chin-throat length (ii)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 66.13** Midface height (a'), lower facial height (a"), upper lip length (b), upper lip vermillion (c), interlabial gap (d), and facial contour angle (e)

Goode's ratio:

of the nose can be evaluated by the method of Goode. According to Goode the length of the nose should be about 55–60% greater than the projection of the nose (Fig. 66.14b). From nasal base to the tip, the ratio of projection should be 1–2 (Fig. 66.14c). The nostrils and columella should be assessed from a "worm's eye" view (Fig. 66.14d). The nasal bridge should project about 5–8 mm in front of the globes of the eyes. The nasal tip should be noted as narrow, bulbous, asymmetric, or normal. The width of the nasal base, the acuteness of the supra tip break, the visibility of the nostrils,

©Association of Oral and Maxillofacial Surgeons of India

and symmetry of the columella are important factors to consider when maxillary surgery (especially superior repositioning or advancement) is contemplated. Fortunately, adverse aesthetic effects as a result of maxillary surgery can be controlled during surgery [4].

#### **Cheeks (Fig. 66.15)**

As in the frontal evaluation, the *cheekbone-nasal base-upper lip-lower lip curve* contour line is also very helpful in the profle analysis. The line starts just in front of the ear, extending forward over the cheekbone, downward over the maxilla adjacent the ala of the nose, and ending lateral to the commissure of the mouth. The line should form a smooth continuous curve, and any interruption may indicate an underlying skeletal deformity (Fig. 66.15). The variations in interruptions in the curve and the possible underlying skeletal deformities responsible for the soft tissue deformities are demonstrated in Fig. 66.15b, c [5].

#### **Orbit**

The globes of the eye generally project 0–2 mm ahead of the infraorbital rims, while the lateral orbital rims lie 8–12 mm behind the most anterior projection of the globes. The bridge of the nose should be about 7 mm ahead of the globes although there is a signifcant ethnic difference in this measurement (Fig. 66.14) [6].

#### **Paranasal Area**

The fatness or fullness of the paranasal areas is an important indicator to distinguish between middle third defciency and mandibular anteroposterior excess. Another useful indicator of midface defciency is the ratio of the linear distance from the nasal tip to subnasale and from subnasale to the alar base crease. The ratio should be 2:1 (Fig. 66.14). A ratio closer to 1:1 will indicate maxillary anteroposterior defciency, while an increased ratio will indicate decreased nasal projection.

#### **Lips**

The lips play an important part in the overall aesthetics of the face and should be carefully assessed before treatment. The effects of treatment as well as the aesthetic changes that may take place during the aging process should be considered. The upper lip usually projects slightly anterior to the lower lip, and the E-line and S-line are helpful guides to assess the projection of the lips (Fig. 66.16) [7].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 66.15** (**a**) The cheekbone-nasal base-lip curve contour. The curve should be unerupted and smooth in an individual with good facial proportions. (**b**) The cheekbone-nasal base-lip curve contour. The interruption of the curve (arrows) indicates maxillary as well as mandibulae

anteroposterior defciency. (**c**) The cheekbone-nasal base-lip curve contour. Following maxillary and mandibular advancement, the curve is uninterrupted and smooth (arrows)

©Association of Oral and Maxillofacial Surgeons of India

**Fig 66.16** Lip prominence. Li should be 2 ± 2mm behind the E-line (Pn-Pog'). Li – Labrae inferioris and Ls – Labrae superioris should just touch the S-line (S-line follows Pog' to the point between Sn and Pn)

#### **Chin**

The chin is one of the most noticeable structures in the face and demands special evaluation. The shape of the chin is more important than the position of pogonion. Chin surgery should not be considered for patients requiring mandibular surgery. Performing an advancement genioplasty for a patient as compromise treatment for mandibular advancement may achieve correct chin projection; however, the balance and harmony of the chin will be poor. The authors use seven criteria for the aesthetic profle evaluation of the chin which also serve as a guide to surgical treatment planning (Figs. 66.11, 66.12, and 66.13) [8].


lower incisors are proclined or in individuals with an increased overjet (Fig. 66.13).


Most of the aforementioned aesthetics parameters can also be assessed on a lateral cephalometric radiograph; however, there is no substitute for clinical evaluation of facial harmony. It is hoped that the short overview of the clinical assessment of facial aesthetics will increase the reader's acuity in the treatment of his/her patients. In most instances the orthodontist is the frst professional to see patients with malocclusions. Some of these patients may require skeletal and/ or soft tissue modifcation incorporated into the treatment plan, and the responsibility lies with the orthodontist to recognize the dental, skeletal, and soft tissue problems and then to appropriately inform the patient. The aesthetic outcome following orthodontic (and surgical) treatment should be a priority for the contemporary orthodontist.

#### **66.3 Clinical Evaluation**

The clinical assessment of the face is probably the most valuable of all diagnostic procedures. While an astute clinical diagnosis can be made at the chair side, photographs are essential for accurate assessment and record purposes. The face is systematically assessed from a frontal view, profle view, and three-quarter view. Figures 66.1, 66.2, 66.3, 66.4, 66.5, 66.6, 66.7, 66.8, 66.9, 66.10, 66.11, 66.12, and 66.13 illustrate some angular and linear parameters used during the clinical assessment of the face.

#### **66.4 Special Investigations**

Cephalometric and panoramic radiographs and dental casts are essential; however, temporomandibular joint investigations, Technetium bone scans, hand wrist radiographs, CT scans, etc. may be required. The lateral cephalometric radiograph taken in centric occlusion and the lips in repose allows the clinician to analyze and evaluate the soft tissue, skeletal, and dental relations of a dentofacial deformity.

#### **66.5 Diagnosis and Problem List**

A diagnosis is made following the clinical evaluation of the patient, a radiographic evaluation and cephalometric analysis, model analysis, and other indicated evaluations. The data base is used to compile a problem list.

#### **66.6 Treatment Objectives**

Clear orthodontic and surgical treatment objectives regarding soft tissue, skeletal, and dental structures should be identifed and noted.

*Development of a Visual Orthodontic and Surgical Cephalometric Treatment Objective* The lateral cephalometric radiograph tracing is used to develop an orthodontic visual treatment objective to predict orthodontic tooth movements. This is followed by the development of a surgical visual treatment objective predicting the required jaw repositioning and expected soft tissue changes [10].

#### **66.7 Treatment Plan**

All the factors identifed in the diagnosis and problem list as well as patient concerns and reasons for considering orthognathic surgery are considered to formulate a fnal treatment plan (Flowchart 1). The sequence of treatment and the treatment to be performed by all healthcare professionals concerned are outlined. When defning the treatment plan, a thorough knowledge of the many types of dentofacial deformities and the treatment modalities available to correct them is essential.

The fowchart (Fig. 66.17) summarizes the systematic gathering of data leading to diagnosis and, fnally, the development of a treatment plan [9–11].

The basic treatment plan will consist of:

#### **Presurgical Orthodontic Treatment**


#### **Surgery**

The treatment of patients with dentofacial deformities can broadly be divided into four groups. The specifc surgical procedure(s) will be indicated by the problem list as discussed:


**Fig. 66.17** Flowchart 1

©Association of Oral and Maxillofacial Surgeons of India

For each of the above surgical treatment categories, the orthodontist and the surgeon will have specifc responsibilities to make the treatment efforts occur smoothly and successfully. In most surgeries, conventional treatment planning using lateral cephalometric and PA cephalometric radiographs and cast model surgery with surgical splint fabrication is indicated. However the authors use 3D virtual treatment planning for more challenging surgeries such as facial asymmetries, rotation of the maxillomandibular complex, etc. [12, 13].

#### **66.8 Treatment**

Although the orthodontist and the oral and maxillofacial surgeon are the main role players, comprehensive correction of dentofacial deformities may involve several members of the healthcare team. The surgeon should understand the orthodontic decision-making process, while the orthodontist must understand the pre- and postsurgical orthodontic requirements. It is mandatory that the therapeutic management is carried out as planned and any problem or change in treatment plan should be communicated to the treatment team. Successful and knowledgeable practitioners always maintain good interprofessional communication and mutual respect to achieve the best treatment results.

#### **66.9 Conclusion**

Successful orthognathic surgery relies on understanding and interpreting a patient's desires, correlating these with the diagnosis, and fnally developing a treatment plan and executing it accurately. While virtual 3D planning has provided another tool to aid in diagnosis and surgical planning, it behooves surgeons to continue to develop profciency in traditional cephalometry-based treatment planning.

#### **66.10 Case Scenarios**

Case 1: A female patient suffering from hemifacial microsomia on the left (Figs. 66.18, 66.19, 66.20, 66.21, 66.22, 66.23 and 66.24).

Case 2: A male patient suffering from skeletal Class 3 malocclusion (Figs. 66.25, 66.26 and 66.27)

**Fig. 66.18** (**a**) Frontal view; (**b**) note the occlusal cant; (**c**) the mandible swing to the affected side; (**d**) right side profle view; (**e**) left side threequarter view, note the microtia; and (**f**) the left side profle view, note the microtia

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**Fig. 66.18** (continued)

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**Fig. 66.19** (**a**–**c**) Presurgical occlusion, (**d**) the occlusion swings to the left on mouth opening, and (**e**) the lower dental midline is displaced to the left (arrows) and bilateral cross bites (circles)

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**Fig. 66.20** 3D images of the skeletal deformities. Note the absence of the left condyle and mandibular ramus (Kaban type III) (i) absence of glenoid fossa, (ii) absence of mandibular condyle, (iii) defcient mandibular ramus on the left side, basal view)

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**Fig. 66.21** The 3D orthognathic virtual surgical plan: Total joint reconstruction on the left, Le Fort I osteotomy correcting of the maxillary cant, unilateral sagittal split ramus osteotomy on the right, and an advancement genioplasty. (i) Pre-surgical, (ii) intermediate position after mandibular surgery, (iii) Final position after maxillary surgery and genioplasty

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**Fig. 66.22** The 3D surgical plan for patient-matched left alloplastic condyle, mandibular ramus and angle

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 66.23** (**a**) Presurgical frontal view, (**b**) postsurgical fontal view. Note the correction of the occlusal cant

**Fig. 66.24** (**a**–**e**) Postsurgical frontal and profle views and occlusion

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 66.25** (**a**–**e**) Frontal, profle, and intraoral views of patient with Class III malocclusion. Patient has paranasal fattening, mandible deviated to right, and fat facial profle. Negative overjet, Class III dental occlusion, and mandibular midline to the right

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 66.26** 2D cephalometric analysis and 2D surgical treatment planning. Surgical plan is Le Fort I downslide, mandibular setback, and advancement genioplasty

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 66.27** (**a**–**e**) Postsurgical views show that the treatment planning goals have been achieved

#### **References**


editors. Oral and maxillofacial surgery. London: Wiley-Blackwell; 2010. p. 973–1012.


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

**67**

## **Surgery-First Orthognathic Approach**

N. Viveka Vardhan Reddy and Abhinand Potturi

### **67.1 Introduction**

Treatment philosophies for the management of dentofacial deformities are varied. Milder forms of dentofacial deformity not manifesting as a signifcant skeletal discrepancy can be corrected by orthodontic treatment alone called "orthodontic camoufage", but those presenting with signifcant skeletal discrepancy need the skills of both the orthodontist and the maxillofacial surgeon. Hence, correction of dentofacial deformities has come to be a confederate work between both specialties. The dentition and maxillomandibular skeletal complex (MMSC) are intertwined, and changes to one will invariably affect the other, especially more so when the MMSC positional and spatial relationships change. Over the years many new concepts have evolved in orthognathic surgery, and the odyssey between the surgical and orthodontic teams is only getting more inseparable and interesting.

#### **67.2 Background**

Looking back to 1960s when techniques of mandibular and maxillary orthognathic surgeries were still evolving from the works of Obwegeser and Trauner, surgeons often performed the procedures either before orthodontic treatment or well after the completion of orthodontic treatment, and rarely any surgeon depended on an orthodontist to move the teeth into certain relationship before undertaking surgery [1]. With time it was realized that the natural dental compensations became a hindrance to the optimal movement of MMSC, thus compromising the results and fnal outcome.

Poulton et al. [1] in 1963 reported few cases of excessive mandibular growth (mandibular prognathism) which were treated surgically without any pre-surgical orthodontics. In the process, the authors observed that the overjet relationship between the upper and lower anterior teeth limited the amount of mandibular setback, thereby compromising the overall treatment outcome. They concluded that proper alignment of teeth in upper and lower arches is a prerequisite to get adequate mandibular setback. This proposal had almost paved the way for the "orthodontics-frst" concept for correcting dentofacial deformities. Worms et al. [2] in the 1970s popularized the concept of "orthodontics frst" for all orthognathic surgeries which led to the split of orthodontic treatment into two phases: the pre-surgical orthodontics phase and post-surgical orthodontics phase with an intervening surgical phase.

The pre-surgical orthodontics phase, which essentially antecedes the orthognathic surgical phase, brings out the accurate skeletal discordance by decompensating the natural compensations which have occurred, thereby helping the surgeon to perform a more precise spatial relocation of the MMSC during surgery [3]. However, the pre-surgical phase of orthodontic treatment, also called reverse orthodontics, is a long-drawn process lasting anywhere between 1 and 2 years depending on the complexity of the discrepancy [4]. To add to the woes, during this phase there is gradual deterioration of facial form and dental function [5–7]. Worsening of the facial profle has become a great deterrent for the patients seeking orthognathic surgery because the very reason for seeking the orthognathic surgery for improving facial aesthetics stands defeated and therefore fails to address the patients' chief complaint. Also, the long preoperative preparatory phase can aggravate or initiate other dental problems like dental caries or periodontal problems. For all these reasons, the "orthodontics-frst" concept can produce a negative infuence on the patient's compliance [8] (Table 67.1).

N. V. V. Reddy (\*) · A. Potturi

SVS Institute of Dental Sciences, Mahabubnagar, Telangana, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1463

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_67

**Table 67.1** Challenges associated with conventional "orthodonticsfrst" approach First – Face Approach:


#### **67.3 Surgery-First Orthognathic Approach (SFOA)**

In order to overcome the shortcoming of conventional orthognathic surgery, a new approach has been conceptualized called "surgery-frst orthognathic approach (SFOA)".

Even though some surgeons expressed the necessity to reposition the MMSC before performing any orthodontics in the past, it did not gain much popularity. With the advent of skeletal anchorage system in orthodontics and rigid fxation system in orthognathic surgery, the problem of skeletal relapse due to unstable bony segments during post-surgical orthodontics has been signifcantly reduced, paving the way for popularization of SFOA [8, 9].

Correction of various skeletal deformities like Class III [10] and Class II [11] and facial asymmetry [12] using SFOA technique has been reported in the past, and all of them claimed shortening of the total treatment time as a signifcant and greatest advantage over the conventional technique. William Bell, the "godfather" of orthognathic surgery, during one of his clinical rounds with his residents, highlighted the changing trends in orthognathic surgery by contending that the present orthognathic surgical procedures remain too complicated, too invasive, too time-consuming, too expensive, and too unpredictable, and he literally set the tone for discussing "paradigm shifts in orthognathic surgery" [13]. After the clinical applications of advanced three-dimensional imaging and offce-based surgery, the 2011 symposium on SFOA created a broader interest in complete elimination of time-consuming pre-surgical reverse orthodontics and paved the way for worldwide acceptance of this paradigm shift in orthognathic surgery [14, 15].

SFOA technique is fundamentally a "face-frst" approach wherein the patient's chief complaint is taken care immediately by improving the facial soft tissue profle and thereby increasing the patient's compliance to overall treatment (Fig. 67.1). In SFOA, greater part of the dentition remains at the same position with respect to their respective arches as there is no pre-surgical orthodontic phase involved. Following the orthognathic surgery, MMSC will be in a Class I relationship, yet the upper and lower dentition may not ft perfectly into occlusion. A *treatable malocclusion*, called *transitional occlusion*, is set at the end of surgery which can be corrected by the orthodontists. Hence, the

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 67.1** The fow diagram demonstrating fundamental differences and the order of priority between the SFOA and conventional approach

#### **Comparison between Conventional technique and SFOA**

**Fig. 67.2** The comparison chart demonstrating various steps for conventional technique and SFOA

orthodontist must actively participate in the treatment planning in SFOA so as to achieve a treatable transitional occlusion at the end of surgery. The orthodontist must be able to foresee the resulting occlusion even before the surgery, and this ability to plan and foresee the resultant transitional occlusion accurately is the linchpin of the entire SFOA technique. Therefore, in SFOA technique the orthodontic principles and guidelines must be established in advance so as to ensure that treatable malocclusions are attained.

Kim JH et al. [8] in their treatise called "Guidelines for "surgery frst" orthodontic treatment" have emphasized caution when embarking on SFOA technique. The entire planning process (Fig. 67.2) is laborious since the skeletal changes should be preconceived and the casts should be mounted accordingly to determine the anticipated postoperative orthodontic teeth movements, and, even for the highly accomplished orthodontic and surgical team, it is challenging to pinpoint accurately the occlusal relationship that will balance ideal aesthetic and functional results. It should be remembered during planning that surgical movement should be adequate enough such that dental decompensation is possible after the surgery. Customarily, the dentition is bonded/banded and a passive arch wire is placed before surgery. Active orthodontic tooth movement begins within a relatively short period of time after the jaw(s) are repositioned to take advantage on the inherent phenomena called accelerated tooth movement [8].

#### **67.4 Regional Accelerated Phenomena (RAP)**

It is observed that the orthodontic tooth movement following orthognathic surgery is rapid and it is signifcantly rapid during initial 4–5 post-operative months. This rapid tooth movement post-surgery is attributed to RAP, and it is observed with all the three planes, sagittal, vertical and transverse.

It is an established fact that orthodontic tooth movement is a metabolic event of alveolar bone resorption in the areas of pressure and bone formation in the areas of tension [16, 17]. In order to analyse post-surgical changes in bone metabolism after orthognathic surgery and the corresponding response in the dento-alveolus, Liou et al. conducted a prospective clinical pilot study in 2011. All 22 adult patients who participated in their study underwent both maxillary LeFort I osteotomy and mandibular bilateral sagittal split osteotomy for repositioning of their jaws. Each of these patients was evaluated for serum alkaline phosphatase (ALP) and C-terminal telopeptide of type I collagen (ICTP) before and after surgery at sequential intervals for up to 4 months post-operatively [14].

ALP and ICTP are two bone markers which are indicative of bone turnover rate. ICTP is a bone resorption metabolite of type I collagen in bone and has been associated with the activities of osteoclasts [18]. ALP is an enzyme for bone formation and has been found to associate with osteoblasts function [19]. The results of Liou et al.'s study [14] showed transient increase in the levels of both ICTP and ALP in the immediate post-surgical period indicating burst in the activity of bone remodelling and turnover activity. It was observed from Liou et al.'s [14] study that the ICTP levels peaked from 1 week to 3 months and the ALP levels from 1 to 4 months post orthognathic surgery. This increase in bone turnover markers in the initial post-operative period is a clear indicator of high metabolic activity in the bone and therefore can be used to advantage in shortening the total treatment time in SFOA.

The RAP is not isolated to SFOA. Even in conventional, orthodontics-frst approach, this phenomenon plays its role in post-surgical orthodontics. The only difference is that in conventional technique the surgery is done after the decompensation is achieved. The SFOA technique utilizes the golden opportunity of RAP by speeding up the decompensation process which occurs after the orthognathic surgery contrary to that in conventional technique. Therefore, in SFOA, the surgical procedure increases the bone metabolic rate of dento-alveolus in the frst 4 post-operative months, which in turn accelerates the orthodontic tooth movement. Hence to make complete use of RAP in SFOA, the post-surgical orthodontic tooth movements have to be begun as early as 1st week and completed by the 4th month.

#### **67.5 Indications**

Though SFOA technique can be employed in any kind of maxillomandibular skeletal discrepancy, Liou et al. proposed the following indications in 2011 (Box 67.1) which could help in easy case selection and will act as a guide for the beginners.

#### **67.6 Treatment Planning Considerations**

#### **67.6.1 General Guidelines**


#### **Box 67.1 Proposed indications for SFOA technique**


Envisioning the fnal dental occlusion based on the present occlusion is the key factor in success of SFOA. The interim transitional occlusion achieved on preoperative model set-up must be stable enough to allow predictable splint preparation and skeletal movement. *It is highly recommended that at least three point contacts are achieved between upper and lower teeth when planning for interim transitional occlusion*. In situations where such transient occlusion cannot be established, it is advisable to commence some orthodontic movement in order to assuage some of the interferences and allow for a more stable transitional malocclusion to be established.

### **67.6.2 Specifc Guidelines** [15]

#### **Anteroposterior and Vertical Decompensation in Class III Cases**


#### **Anteroposterior and Vertical Decompensation in Class II Cases**


### **67.7 Treatment Protocol** (Table 67.2)

The protocol variations between the conventional orthognathic surgery and SFOA can be clearly appreciated in the Table 67.2 highlighted in Bold fonts. A simulation of pre-

**Table 67.2** Treatment protocol comparing SFOA technique to conventional technique


surgical orthodontic treatment using model mounting and set-up will compensate the pre-surgical orthodontic treatment.

#### **67.8 Protocol Variations**

Although the sequence of treatment is similar, different protocols are being used to prepare the patient for surgery, perform the operative procedure, and commence the orthodontic treatment.

#### **67.8.1 Timing of Bonding**


#### **67.8.2 Initial Arch Wires**


Placement of passive stainless steel arch wires bent and adapted to each tooth before surgery will preclude any untoward tooth movement during or immediately after the surgery. The authors wishing to capitalize on the RAP concept immediately after surgery prefer to place active nickeltitanium arch wires prior to surgery. Nonetheless, in doing so, the orthodontist loses an opportunity to observe the stability of the surgical correction prior to beginning of the tooth movement. The rapid acceleratory phenomenon not just infuences the tooth movement but also can disturb the alveolar bone [8].

There are also protocol variations regarding the usage of surgical splints after the surgery among the various authors. While some authors suggested the use of the surgical splints only intraoperatively, others have advocated its use anywhere between 1 and 4 post-operative weeks. Nagasaka et al. have used removable Gelb-type splints post-surgery [10]. Kim's preference is to leave the splint in for about 1 month to 1 and a half months post-operatively and if an open bite is observed to use elastics between the splint and the mini-screws placed into the bone or to leave the splint for an even longer time

#### **67.9 Procedural Guidelines for Model Mounting and Model Set-Up in SFOA**  (Fig. 67.3)

period [8].


#### **67.10 Surgical Procedures** (Fig. 67.4)

The surgical procedures in the maxilla, mandible or chin are themselves performed using described standard techniques, whether it is the conventional technique or the SFOA technique.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 67.3** (**a**) Standard model mounting. (**b**) Before the procedure, the teeth that have adapted to the skeletal discrepancy are simulated and reorganized into their predicted location, similar to real pre-surgical orthodontic treatment. (**c**) Simulation of actual orthognathic surgery is then performed. (**d**) Surgical splints fabricated to aid in real-time surgery

**Fig. 67.4** Flow diagram showing various surgical procedures in each of the jaws

©Association of Oral and Maxillofacial Surgeons of India

#### **67.11 Advantages and Disadvantages of SFOA** (Table 67.3)

Systematic review published by Peiró-Guijarro et al. [21] in 2006 reviewed 179 publications and fnally selected 11 articles for fnal reporting. They found that the SFOA technique was most commonly reported in Class III skeletal malocclusion than in skeletal Class II malocclusion with prevalence of about 84.7%. The single largest advantage described was shortened treatment duration time owing to the RAP concept, and the disadvantage was potential error in predicting the post-operative occlusal outcome resulting in greater or lesser surgical movements of the jaws.

#### **67.12 The Future of "Surgery-First" Approach**

The future of SFOA technique lies in using augmented skull models, virtual orthodontic set-up to replace the mounted study model set-up and the computer-aided design and computer-aided manufacturing fabrication of intraoperative splints (Fig. 67.5). The 3D virtual orthodontic set-up will help the orthodontist to predict the eventual (at the end of orthodontic treatment) position and the axial inclination of each tooth scrupulously. This is a compelling step before the surgeon's skeletal base correction simulation, since the patient's prevailing occlusion

**Table 67.3** Advantages and disadvantages of the surgery-frst approach

#### *Advantages*


#### *Disadvantages*


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 67.5** The workfow demonstrating the pre-surgical orthodontic movement set-up (**a**), the surgical procedure on the maxilla (**b**), the procedure on the mandible (**c**), the post-operative ensuing dental occlusion with splint in situ (**d**, **e**) and the design of the fnal splint (**f**)

cannot serve as a guide for skeletal repositioning as it lies in a compensated state.

Usability of temporary anchorage devices (TAD) and interdental corticotomies is a factor which can add to the future of SFOA. The TAD permits a wider range of orthodontic vectors and avoids premature bracket loading with secondary troublesome dental extrusion. Interdental corticotomies can augment the RAP and further enhance the orthodontic treatment duration.

#### **67.13 Conclusion**

Performing orthognathic surgery even before any orthodontic tooth movement (SFOA) offers a unique advantage of addressing the patient's chief complaint at the very beginning, thereby improving the acceptance and compliance of the patient to overall treatment. It also offers the big advantage of signifcant decrease in total duration time by making use of the RAP. The fnal outcomes, in the way of facial aesthetics, dental occlusion and stability, are similar when using orthodontics-frst and surgery-frst approaches. However, it must be remembered that both the surgeon and the orthodontist must trend with care as there is a premium on patient selection and both should be involved as a team during every stage of the treatment, starting from diagnosis to debonding. Surgeonorthodontist team should know the orthodontic principles and understand the limits of orthodontic teeth movement and must accommodate dental decompensation in their initial treatment planning. The surgeon should be capable of carrying out designated osteotomy and intermaxillary fxation with occlusion bite plate on misaligned dental arches and providing the stability after skeletal reposition. The future of orthognathic surgery is geared towards reducing the overall treatment duration without compromising the fnal outcome.DisclosureAuthors have no fnancial conficts to disclose.

#### **67.14 Case Scenarios**

**Case Scenario 1** (Fig. 67.6)

**Case Scenario 2** (Fig. 67.7)

**Fig. 67.6** Case Scenario 1. A 19-year-old male presenting with forwardly place upper front teeth. (**a**–**c**) Preoperative pics showing frontal, profle and right lateral views. (**d**, **e**) Preoperative occlusion showing end on molar relation and compensated dental occlusion with anterior deep bite and excessive overjet. (**f**, **g**) Post-surgical orthodontic treatment in progress. Excessive nature of curve of Spee can be noted, and the change in overjet and overbite post-surgery can be appreciated. (**h**– **j**) Post-treatment facial pics: frontal, smiling and lateral views. (**k**, **l**) Post-treatment intraoral pics. (**m**, **n**) Comparison of pre-operative and post-operative lateral cephalograms

**Fig. 67.6** (continued)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 67.6** (continued)

**Fig. 67.7** Case Scenario 2. A 26-year-old male presenting with prominent lower facial appearance and mobile lower front teeth. (**a**, **b**) Clinical pics showing lateral and frontal views: Concave facial profle can be appreciated with acute nasolabial angle. (**c**) Lateral cephalogram showing skeletal Class III jaw bases with normodivergence. (**d**, **e**) Intraoral picture showing reverse overjet, Class III molar relationship

and spacing in lower anteriors. (**f**, **g**) Post-surgical orthodontics in progress. Reversal of overjet can be noticed. (**h**–**J**) Post-treatment facial pics in profle and frontal. (**k**) Intraoral post-treatment pic showing occlusal relationship with normal overjet and Class I molar relationship. (**l**) Postoperative cephalogram

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 67.7** (continued)

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

Varghese Mani

#### **68.1 Introduction**

Proper balance and harmony between the different parts of the face—forehead, eyebrows, eyes, nose, ears, cheeks, lips, mouth, jaws, chin, etc.—are the main factors deciding aesthetics. Aesthetic evaluation is mandatory to understand the problems systematically. During the primate evolution, jaws lost many functions, and the size suffered a gradual reduction, which resulted in an orthomorphic face. The facial muscles gained fne expression and smile, the exceptional features of *Homo sapiens*.

Mandible forms the movable lower part of the head. Mandible is attached to the upper part of the head by ligaments and musculature. It articulates with the glenoid fossa of temporal bone through temporomandibular joint, a synovial joint having translator and rotator movements (ginglymoarthrodial). These movements facilitate chewing and grinding functions. In our prehuman ancestors, the body of the mandible was parallel. In humans, since the brain case has expanded, the temporal bones were pushed apart, TMJ followed suit giving the lower jaw a parabolic contour. The Simian shelf reduced to genial tubercles to facilitate speech and to compensate and strengthen the jaw and the chin developed in humans. Metaphorically it is often stated that "the brain case has expanded at the expense of the jaws".

In some people, surgical repositioning of the mandible may be required to achieve an ideal facial form and restore functions such as mastication and breathing.

#### **68.2 Surgical Anatomy of the Mandible**  (Fig. 68.1a, b)

Mandible is the sturdiest bone of the face with strong basal bone and the alveolar part housing the dentition. The near round protuberances seen bilaterally at the cephalic end of the mandible are called condyles, and they form its articulation with the TMJ. The mandibular condyles articulate with the temporal bone and help in the rotatory and translatory movements of the mandible as well as to transmit forces from the mandible to the skull base. A good understanding of the gross anatomy of the mandible is essential to understand its surgical implications. This needs to include the TMJ, the dentition, the supporting ligaments, and the muscles of mastication (Fig. 68.2a, b) and facial expression.

On the medial aspect of the vertical ramus is the mandibular foramen just posterior to halfway between the anterio-posterior width of the vertical ramus almost in line with the most concave part of the anterior border of the ramus. Just above is the lingula, a triangular prominence to which the sphenomandibular ligament is attached. Mandibular neurovascular bundle enters the mandibular foramen on the lingual side of the mandible and runs below the tooth roots in the body of the jaw, in the inferior alveolar canal. It curves upward and backward by about 2 mm and gives out the main branch, mental nerve, below the second premolar area, and gives sensory supply to the lower lip and chin [1].

**Orthognathic Surgery for Mandible**

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_68) contains supplementary material, which is available to authorized users.

V. Mani (\*)

Department of Oral and Maxillofacial Surgery, Mar Baselios Dental College, Kothamangalam, Kerala, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1477

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_68

**Fig. 68.1** (**a**) Gross anatomy of mandible, (**b**) ligaments attached to mandible

#### **68.3 Classifcation of Deformities of the Mandible** (Table 68.1)

Deformities of the jaws can be associated with the dento-alveolar complex, the skeletal base or both.

They may be either an excess or a defciency.

These problems can occur in three different vectors: Antero-posterior, Transverse and Vertical

Before venturing into the classifcation of the jaw deformities it will be appropriate to assess the relationship of the lower jaw to the rest of the face. Certain parameters are used to assess the deformity objectively. Clinical evaluation is the most important of them all. Face has to be assessed frontally and laterally.

Profle analysis of the face is the most important of them all—it could be convex, straight, or concave. Convexity can be due to protruded maxilla or retruded mandible/chin. Concave face can be due to retruded maxilla or prognathic mandible/chin (Fig. 68.3a, b, c).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 68.3** On profle analysis face can be convex (**a**), straight (**b**), or concave (**c**)

©Association of Oral and Maxillofacial Surgeons of India

Subnasale perpendicular is another important tool for assessing the profle. A line is drawn perpendicular to the Frankfort horizontal plane through the point Subnasale. This line is expected to go through the upper vermilion border, 2 mm anterior to the lower vermilion border and 4 mm anterior to the soft tissue (Fig. 68.4) Pogonion. +/–2 mm is considered to be within normal limits. This is an important assessment tool for understanding the sagittal relationship of both the maxilla, mandible and dentition.

Likewise another perpendicular line is drawn from Nasion. (N. Perpendicular). This line is ahead by 5.3 ± 6.7 mm in males and 6.9 ± 4.3 mm in females. This indicates the position of mandible. Regarding the bony pogonion this line is ahead by 4.3 ± 8.5 mm in males and 6.5 ± 5.1 mm in females. This indicates the position of the chin. Angle SNB is 80 ± 2 normally. Less indicates retruded mandible and more indicates protrusion of mandible. All these measurements are in relation to the cranial base, the portion that is not changed in routine orthognathic surgery. (Fig. 68.5) (Refer Chap. 66 for further details).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 68.5** Nasion perpendicular to FH plane

	- (a) Skeletal
	- (b) Dento- alveolar
	- (a) Skeletal
	- (b) Dento- alveolar
	- (a) Broad
	- (b) Narrow
	- (a) Vertical
	- (b) Transverse
	- (c) Antero posterior
	- (a) Vertical
	- (b) Transverse
	- (c) Antero posterior

Specifc conditions like presence of deep bites and open bites can occur with these clinical situations and may help us understand the dentoalveolar compensations that occur with them. Assessment of patients is done with facial analysis and cephalometrics.

#### **68.3.1 Mandibular Excess**

Common cause for mandibular excess is either developmental or genetic. Very large mandible may be associated with acromegaly.

The clinical features associated with mandibular excess are the following:


#### **68.3.2 Mandibular Defciency**

It is often due to genetical or developmental reasons. Ankylosis of temporomandibular joint, trauma to mandibular condyle and aplasia of condyle can also cause defciency in mandibular growth.

Clinical features associated with mandibular defciency are the following:


#### **68.3.3 Deformities of Chin**

Deformities of chin could be three dimensional—vertical, anterio-posterior, or horizontal.

Vertical and anterio-posterior excess of chin are usually associated with mandibular prognathism. Though in prognathic mandible, chin appears prominent, it need not be so in objective analysis. Hence it is essential that the chin be assessed independently in relation to the other structures. To assess the vertical discrepancy, the best technique is to measure the length from stomion of the lower lip to the menton and compare this to the length obtained from measuring the subnasale to stomion of the upper lip, in rest position. The former should be double the latter normally.

#### **68.3.4 Facial Asymmetry**

The reasons for facial asymmetry are many.


Asymmetry could be pan facial or limited to certain areas. Frontal analysis is the ideal method to assess asymmetries. Drawing vertical and horizontal parallel lines on the face will help to locate the area of asymmetry. This can also be done using a grid. PA cephalogram and frontal photographs are helpful in analyzing facial symmetry.

Orthognathic surgery to the mandible involves numerous procedures that facilitate the correction of deformities of the mandible and its dentoalveolar complex in all planes of space. This encompasses a wide array of techniques which may be classifed based on the anatomical location they are applicable to.

Osteotomies of the Mandible

	- (a) Anterior subapical
	- (b) Total subapical
	- (a) Vertical sub-sigmoid osteotomy—intra- and extraoral

The discussion of all the techniques is beyond the scope of this chapter, and hence, detailed description of the vertical ramus osteotomy, the sagittal split ramus osteotomy, and theÚnterior subapical osteotomy are provided here.

#### **68.4 Ramus Osteotomies**

Movement of the mandible in the antero-posterior direction is usually achieved by ramus osteotomy. Limberg in 1925 reported subcondylar oblique osteotomy [2]. Thomas, Robinson, Shira, and others described buccal osteotomy which involved the ramus. Later, Caldwell and Letterman (1954) described vertical subcondylar osteotomy by extraoral approach, which became very popular [3]. This technique minimized trauma of the inferior alveolar neurovascular bundle.

In 1927 Wassmund described the inverted "L" osteotomy. Though the primary indication was mandibular prognathism, many surgeons advocated vertical osteotomy and certain modifcations like inverted "L" osteotomy [4] and "C" osteotomy for advancement of the mandible [5]. Bone grafting has to be done to fll the gap created (Fig. 68.6).

In 1937 Lane described a sagittal osteotomy. Obwegeser modifed the Lane's technique in 1955, and the technique of sagittal split osteotomy is credited to him. Sagittal split is a versatile technique and has the following superiority over others [6]. It gives great fexibility in repositioning the distal tooth-bearing segment. There is better cancellous bone contact, which enhances healing. The alterations in the position of the condyles and muscles of mastication are minimal. There is no extraoral scar. Injury to the marginal mandibular nerve is avoided. However, chance of injury to the inferior alveolar neurovascular bundle is high [7].

Dal Pont made the modifcation to sagittal split by a vertical cut through the lateral cortex [8]. Hunsuck extended the medial cut only to a point above the lingula. This minimized trauma to overlying tissue [9].

#### **68.4.1 Extraoral Vertical Ramus Osteotomy**

This was one of the most popular procedures for correcting mandibular prognathism. Rigid internal fxation techniques and certain modifcations like "C" osteotomy and inverted "L" osteotomy have been used for advancement of the mandible. After "C" or "L" osteotomy, the gap created while advancing or rotating the distal segment is flled with bone graft [10].

The major disadvantages are the external scar and the possible inadvertent damage to the marginal mandibular nerve. With judicious care, these problems can be minimized. Better visibility is the major advantage (Fig. 68.7).

#### **Surgical Technique:**

Submandibular skin incision is placed, about 1.5 cm below the angle of the mandible. The incision is taken down to the platysma, which is then divided. Marginal mandibular nerve lies below the platysma running parallel to and often below the lower border of the mandible, crossing the facial vessels superfcially as it passes upward. Attempt should be made to identify this structure and preserve it.

After identifcation and protection of the marginal mandibular nerve, dissection is carried down to the bone. The periosteum is incised over the angle. The periosteum is refected superiorly to the level of the sigmoid notch on the lateral aspect of the ramus. Coronoid process may be cut in cases when more than 1 cm of posterior movement is required (Fig. 68.8).

Lateral aspect of the ramus is inspected for a small bulge corresponding to the lingula. This helps to identify the mandibular foramen. Osteotomy is performed posterior to the anti-mandibular foramen bulge so that the mandibular nerve is not injured. (The position of the bulge is arbitrary and not defnite.) A vertical bony cut is made starting at the sigmoid notch and progressing to the lower border near the angle of the mandible. Condylar segment is separated from the distal part of the mandible and is detached from the medial pterygoid muscle. The condylar part is

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**Fig. 68.6** Inverted "L" osteotomy of the ramus used for advancing the mandible

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**Fig. 68.7** Subsigmoid vertical osteotomy was the most popular technique before the introduction of sagittal split osteotomy. This technique is used for correcting mandibular prognathism

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**Fig. 68.8** When the push back required in subsigmoid vertical osteotomy is more than 1 cm, sectioning of the coronoid process helps in better stability

laterally placed on the distal segment. After packing the wound, the same steps are followed on the contralateral side.

The mandible is repositioned into the desired position with the help of the splint, and intermaxillary fxation is done. The site of surgery is again approached. Some surgeons prefer to leave the condyle as such on the lateral aspect without any transosseous wiring. There is no consensus regarding the decortication of the opposing surfaces.

Removal of bone or decortication may be done if it helps the condyle to achieve a proper position within the glenoid fossa with minimal displacement. Decortication helps better contact of the cancellous bone enhancing healing. Stabilization of the fragments by transosseous wires or screws and plates can be done. Rigid internal fxation eliminates intermaxillary fxation. Except in rigid internal fxation, intermaxillary fxation for a period of 4–6 weeks is mandatory. After the fxation is removed, elastics may be used to guide the movements.

Wound closure is done in layers. Skin may be closed by monoflament 6-0 or smaller sutures. A pressure dressing is applied for the frst 24–48 h. Drain is usually not necessary and, if done, has to be done through a separate stab incision below the main incision. Sutures are removed after 5–7 days, and the wound is supported by dressing for a period of another 1 week, if required.

Complications are usually rare. Bleeding may occur due to injury to the retromandibular vein or masseteric artery where it crosses laterally through the sigmoid notch. Bleeding can be controlled by routine methods like pressure packs, ligation, etc. Injury to the marginal mandibular nerve is another possibility. A transitory defciency in the function of the lower lip may be anticipated due to traction on the nerve. This often recovers completely. In case of sectioning of the nerve, micro-surgical repositioning is advised.

If care is taken in closure, and infection is avoided, scar formation is minimal. If scar is formed, revision may be done subsequently (Fig 68.9a−d).

#### **68.4.2 Sagittal Split Osteotomy**

Sagittal split osteotomy (SSO) can be employed for correcting both retrognathism and prognathism. Modifcations by Dal Pont, Hunsuck, and Epker have made the procedure simpler and more acceptable biologically. Schuchardt and Lane described sagittal split osteotomy of the vertical ramus [11]. It was Obwegeser who popularized it. His medial cut was above the mandibular foramen, and his lateral cut was below that of Schuchardt's and extended to a part just above the angle, at least 25 mm below the lingual cortical cut. Obwegeser and Trauner in 1955 described the bilateral sagittal split osteotomy [6].

Dal Pont in 1961 made a major modifcation by extending the cut anteriorly and making the vertical cut just below the second molar [8]. Hunsuck in 1968 modifed the cut in the medial cortex of the vertical ramus, limiting the cut to just behind the mandibular foramen. Postoperative complications got reduced [9] (Fig. 68.10a, b).

Bell and Schendel and Epker extended the vertical cut on the buccal side to the lower border of the mandible reducing the incidence of wrong splits [12, 13]. A reciprocating osteotomy saw, which is specifcally meant for the inferior border (right and left) may be used to perform inferior border osteotomy [14].

Performing an inferior border osteotomy results in much lower incidence of persisting inferior border defects. Hence, during advancement of the mandible, it is advisable to exclude the lingual cortex in the split. Piezosurgery has been compared with conventional surgical drills/saws by several authors for BSSO. They have reported substantially longer surgery time for piezosurgery. Image-guided surgery has also become popular in the recent years, and this allows the surgeon to track the position of the instruments and segments during the operation in real time. Modern intraoperative navigation systems are being used in orthognathic surgery also [15].

A. Incision and Dissection:

Incision is placed over the region of the ramus to the mid ramus. It is carried over the external oblique ridge, extends up to the frst molar region, and curves down to the buccal vestibule.

Initially only the mucosa is incised over the ramus region. Retracting the tissue buccally, before incision, prevents the exposure of the buccal pad of fat, a troublesome interference, during surgery. Sharp dissection at the ramus is continued to the periosteum, using scissors, knife, and periosteal elevators.

Periosteal elevation of the lateral aspect of the mandible at the molar region is performed down to the inferior border. On the ramus, lateral dissection may be kept minimal but enough to achieve proper visibility and access.

Medial dissection is done very carefully on the medial side of the ramus. The level of the lingula and the entry of the inferior alveolar nerve into mandibular foramen are visualized. This is usually in level with the deepest concavity along **Fig. 68.9** Mandibular prognathism corrected by subsigmoid vertical osteotomy of the ramus on both sides to set back the mandible. (**a**, **b**) Preop pictures, (**c**, **d**) postop pictures

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the anterior border of the coronoid and ramus. With a small fexible Freer Elevator, the tissue is dissected taking care not to perforate the periosteum on the medial aspect. Dissection should be above the level of the mandibular foramen. Using a bigger elevator, the medial aspect of the mandible above the lingula is exposed subperiosteally. (Perforation of the periosteum not only induces bleeding but may injure the mandibular nerve.) Sigmoid notch is identifed for better orientation. Subperiosteal dissection should be minimal, but enough to retract the tissues medially without much traction on the mandibular neurovascular bundle [16].

#### B. Osteotomy (Videos 68.1 and 68.2):

Osteotomy is initiated by cutting the cortical bone above the lingula on the medial side. This cut should extend behind the mandibular foramen but need not be up to the posterior border of the ramus (about half to two-thirds of the anteroposterior dimension of the ramus). The cut is taken downward along the external oblique ridge to the second or frst molar region. The depth of the cut should be minimal, just enough to reach the cancellous bone (Figs. 68.11 and 68.12).

Conventionally the vertical cut is made at the second molar region as the bone is thicker there. The CT analysis conducted by Y Tsuji et al. on prognathic mandible demonstrated that the mandibular thickness of the mandible increased along the mandibular foramen toward the mandibular body. The mandibular canal was located relatively lingually at all sites. They also observed that marrow space, located on the buccal side, was thicker at the region of mandibular body [17].

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**Fig. 68.10** Bilateral Sagittal Split Ramus Osteotomy (BSSO/BSSRO). (**a**) Obwegeser split: Initially the medial cut in sagittal split osteotomy extended up to the posterior border, and when the distal segment was pushed back, the margin used to jut out, which had disadvantages like

relapse tendency and injury to the retromandibular tissues. (**b**) Hunsuck split: At present the medial cut is taken above the mandibular foramen much short of the posterior border but behind the foramen. The complications are much less (also see Fig. 65.12b)

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**Fig. 68.11** The medial cut is taken above and behind the mandibular formen and deepened to the cancellous bone

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**Fig. 68.12** The cut is extended obliquely through the anterior border of the mandible to the buccal plate and taken downward at the level of the frst or second molar region, up to the inferior border. Only the cortex need be cut. Deeper cuts could injure the inferior alveolar nerve and may cause wrong splits (also see Figs. 69.31 a–c and 70.24 c, d)

A study on cadaveric mandible by Promma et al. reported that the thickness of buccal cortex to the mandibular canal is about 6.5 and 5 mm at the second molar and frst molar regions, respectively [18].

Some surgeons prefer to take the cut more forward to the frst molar region. This gives better accessibility for intraoral plating. When the vertical cut is made, it is mandatory to protect the soft tissue over the inferior border by using a channel retractor. If the vertical cut includes the inferior border, the direction of the split is controlled. A rotary instrument or a reciprocating saw is used for cutting. Once the cortical cut is completed, a small spatula osteotome is malleted to the site beginning from the medial cut to the vertical cut. Osteotome should be directed laterally just beneath the cortical plate so that the neurovascular bundle is not injured. Larger osteotomes are used, and slowly the fragments are pried apart using a smith spreader (Fig. 68.13).

As the splitting takes place, the neurovascular bundle is visualized, and care is taken to maintain it to the medial fragment. If it is attached to the proximal segment, the NV bundle is freed with a periosteal elevator. Next the fragments are pried apart using the spreader. The procedure is repeated on the opposite side.

Sagittal split osteotomy can be used for either mandibular advancement or setting back. If mandibular advancement is to be done, the medial pterygoid muscle is separated from the inferior border of the distal segment with a periosteal elevator. When the mandible is set back, medial pterygoid and masseter may have to be stripped, if needed, to prevent the displacement of the condylar segment posteriorly. Posterior stripping of the pterygomasseteric sling in SSO should be minimized to the antegonial notch. In excessive stripping, possibility for avascular necrosis increases [19].

When the tooth bearing segment (distal segment) is pushed back, the buccal plate of the condylar segment (proximal segment) overlaps the distal. This overlapping part is excised, and the proximal segment is allowed to rest on the cancellous part without any tension (Fig. 68.14).

Pushing the mandible backward reduces the space in the oral cavity. The tongue may not have enough space, and sometimes this induces tongue thrusting, snoring, etc. Some authors advocate reduction glossectomy to improve function related to airway speech and mastication. They also opine that reduction glossectomy improves aesthetics and controls unfavorable mandibular growth [20].

Mommaerts reported that mandibular lengthening done through endoscopic surgery, with transoral osteosynthesis, reduced stripping of the periosteum and therefore consequent edema [21]. In certain clinical situations Unilateral sagittal osteotomy is performed. Refer case scenario in Fig. 69.31 (Maxillary orthognathic surgery Chap. 69) where an unilateral sagittal osteotomy was combined with maxillary osteotomy to correct canting of the maxilla.

C. Stabilization and Fixation:

Rigid internal fxation (RIF) using plates and screws or lag screws is the preferred way of fxation. Prior to RIF, the position of the jaw is adjusted, and intermaxillary fxation is done with splint in position. Both fragments are allowed to be in passive position before RIF is performed. Intermaxillary fxation (IMF) is removed after rigid fxation. However, some surgeons prefer to keep the IMF for 1 week. For rigid fxation 2.5 mm four-hole mini plate with gap is used for push back (Fig. 68.15). Longer plates are used for advancement. Multiple lag screws can also be used. Skeletal rigid fxation has been shown to reduce relapse following mandibular advancement [22–24] (Figs. 68.16a, b, c, and 68.17a, b, c).

V. Mani

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**Fig. 68.13** A spreader is used to split the mandible at the ramus region

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**Fig. 68.14** Excess of the buccal plate is cut off when the intention is to push the mandible backward

Rachmiel et al. in their study found improved stability with four-hole plate and monocortical screws, with a relapse rate of about 18% only [25].

Based on a 10-year experience of using bioresorbable plates in orthognathic surgery, Laine P et al. opine that these devices are safe to be used. Relapse rate with bioresorbable screws is the same as with metal in SSO [26]. Another method of fxation is wiring. If resorting to wiring, intermaxillary fxation has to be kept for 5–6 weeks. Maturation of soft and bony

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**Fig. 68.15** Rigid fxation after sagittal split osteotomy of the mandible using mini plate

tissues continues at the surgical site and approximates that of non-surgical sites at 12 weeks postoperatively [27–29].

The inferior alveolar nerve is less likely to get damaged when monocortical screws are used. These screws also allow for readjustment if there is any inadvertent malposition during surgery can be readjusted more easily [30]. An in vitro study on sheep mandibles found that both mini plates and bicortical screws resulted in a similar level of stability [31]. (Figs. 68.18a, b, c, d, 68.19a, b, c, and 68.20a, b, c). D. Wound Closure:

Wounds are irrigated well and bleeding is controlled by routine methods. If there is continued bleeding drain is indicated. Wounds are closed by 3-0 Vicryl sutures.

E. Postoperative Sequelae:

Edema is expected after sagittal split osteotomy. It resolves within 2 weeks. Edema at the angle is the last to resolve. Suction drainage minimizes tissue edema following mandibular surgeries. Betamethasone administration signifcantly reduces postoperative edema. Widar H. et al. has also observed less bleeding intraoperatively, but no difference in neurosurgery disturbances [32].

Diminished sensation over the lip is experienced by most of the patients and is mainly due to traction on the neurovascular bundle. If there is no injury to the neurovascular bundle, sensation returns within a few weeks. More than two-thirds of the patients experience some sensory defcit even after 1 year. However, most of the patients get adjusted to this altered sensation and are satisfed with the overall result. Limitation of movements of jaw in all direction after osteotomy is often experienced. Sagittal split advancements often cause signifcant limitation of range of motion [33].

**Fig. 68.16** Bilateral sagittal split osteotomy to set back the mandible, with rigid fxation. (**a1**, **b1**) Preoperative photographs. (**a2**, **b2**) Postoperative photographs. (**c1, c2**) Pre and post operative lateral cephalograms with superimposed tracings

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Physiotherapy following rigid fxation showed minimal limitation [34].

F. Complications:

Important complications associated with sagittal split osteotomy are:


1. Bad Split:

A systematic review of fracture patterns in sagittal split was analyzed by Steenen and Becking and reported 2.3% bad splits in sagittal splits. The most common was buccal plate fracture of the proximal segment and lingual plate fracture of the distal segment. Coronoid and condylar neck fractures were seldom [35].

Wrong split usually occurs in cases where the last molar is removed at the time of surgery. Hence it is advised to have the third molar removed (if needed) about 6 months

**Fig. 68.17** Case of mandibular prognathism with maxillary defciency, managed by maxillary advancement and mandibular set back by BSSO. (**a1**, **b1**) Preop pictures. (**a2**, **b2**) Postop pictures. (**c1**) Preop cephalogram. (**c2**) Postop cephalogram

prior to the osteotomy. If the lingual cortical plate is broken, soft tissue separation from the lingual plate should be kept to the minimum, so that the blood supply is not jeopardized. Patients with a shorter ramus and buccolingually thin mandible are more susceptible to wrong split during SSO [36]. Advanced age can increase the risk of a bad split. Use of a spreader helps to reduce the incidence of wrong splits.

2. Injury to the Neurovascular Bundle:

Care should be taken to maintain the continuity of the neurovascular bundle. If it is transected, ideally the cut ends are micro-anastomosed. However, in common practice, where a micro-surgeon may be unavailable, it is advisable to perform direct suturing to attain epineural approximation. With a repositioned and repaired neurovascular bundle, the sensation is recovered though the period it takes is longer.

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**Fig. 68.17** (continued)

Long-lasting neurosensory defciency (NSD) was underestimated by the surgeons as compared to the patient's subjective symptoms. Long-lasting NSD was reported as 7.5% (Questionnaire) and 3.8% (Record), after intraoral vertical ramus osteotomy, and as 11.6% (Questionnaire) and 8.1% (Record) after sagittal split osteotomy [37]. Vertical subsigmoid osteotomy with rigid fxation may be considered as a viable alternative if it is important to avoid alterations in sensation, whereas BSSO maybe preferred if retromandibular scar is of concern. Neurosensory disturbance, after SSO with additional genioplasty, is more than after SSO alone [38].

#### 3. TMJ Problems:

Care should be taken while plating the segments. Improper plating can pull or push the condyle to an untoward position. Postoperative X-rays are taken to assess the situation. If needed, the displacement has to be corrected by returning the patient to surgery. Displacement of the condyle from the fossa is one of the main reasons for relapse [24, 39] (Fig. 68.21).

Beukes J. et al. in 2016 studied condylar rotational tolerance in BSSO treatments and reported a range of 10 –15 after orthognathic surgery.

Unilateral SSO is a safe procedure in lateral prognathism of mandible due to unilateral condylar hyperplasia or traumatic malocclusions [40]. The condyle that was not operated on, only rotated 3–4° within the glenoid cavity, and it was established that this is within the range of functional articular adaptation [41]. Mendez-Manjon R. et al. observed that mandibular advancement by BSSO can positively displace the condyle especially on the posterior aspect [42].

In their study Borstlap et al. observed that in sagittal split advancement postoperatively, 8% of patients showed postoperative condylar resorption. Patients of relatively low age are at risk of condylar alterations or resorption. Occurrence of pain and TMJ sounds in the frst few months postoperatively are highly indicative of condylar changes to occur in the preceding months [43]. Predisposition in females for condylar resorption after sagittal split osteotomy may be attributed to

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**Fig. 68.18** A case of left unilateral ankylosis of the TMJ resulting in trismus and facial deformity. Treated by release of ankylosis by gap arthroplasty, temporal myofacial fap interposing, and extended lateral

sliding genioplasty. (**a**) Pre operative picture before ankylosis correction (**b**) frontal view with facial asymmetry (**c**) after release of ankylosis, (**d**) after correcting facial asymmetry

the modulation of biologic response, by estrogen and prolactin [44]. Mobarak compared the skeletal stability of postoperative changes in low angle and high angle Cl II patients following mandibular advancement. High angle had more horizontal skeletal relapse due to condylar movement in a superior direction. Changes in intercondylar angle and width after BSSO advancement or set back may infuence TMJ function [45–48].

#### 4. Excessive Bleeding:

Bleeding can be from inferior alveolar neurovascular bundle, medullary bed, and facial vessels or rarely from retromandibular vein. Bleeding from the former two can be controlled by local measures; but the facial vessels will have to be clamped and tied, for which an extraoral incision may be required. Using the channel retractor with a cup to hold the inferior border and cutting with a Steiger-type carbide bur (this has side cutting and rounded cutting end and cuts bone with minimal injury to the soft tissue) prevents injury to the facial vessels.

Injury to the retromandibular vein is very rare and is due to inadvertent injury to the soft tissues behind the mandible. Bleeding can be controlled by absorbable gelatin sponge. Excessive oozing can cause signifcant edema, and if oozing is present, a drain may be placed.

**Fig. 68.19** Facial asymmetry and vertical and sagittal excess of maxilla corrected by LeFort1, anterior maxillary osteotomy, bilateral sagittal split osteotomy and advancement genioplasty. (**a1**, **b1**) Preoperative pictures. (**a2**, **b2**) Postoperative pictures. (**c1**) Preoperative lateral cephalogram. (**c2**) Postoperative lateral cephalogram

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**Fig. 68.19** (continued)

#### **68.4.3 Vertical Ramus Osteotomy: Intraoral Approach**

It was Caldwell and Letterman who developed the intraoral vertical ramus osteotomy in 1954 [3]. Later in 1964, this was described by Moose [49] and Winstanley in 1968 [50], and modifcations have been suggested by many others. Intraoral approaches medially and laterally to ramus were described [49, 50]. Herbert and associates in 1970 described the use of special oscillating saw and popularized the intraoral technique to reach the ramus (Fig. 68.22).

The procedure overcomes the disadvantages of extraoral vertical ramus osteotomy. The advantages are the following: (1) external scar is avoided and (2) there is no injury to the marginal mandibular nerve. The advantages over sagittal split osteotomy are that injury to the mandibular neurovascular bundle is avoided. The main disadvantage is the diffculty in access and visualization of the area. However, there is a delay in healing and possibility of projection of antegonial notch [51]. Mandibular nerve hypoesthesia can be expected to improve faster in young patients than the older ones. So IVRO may be a better option for elder patients [52].

#### **Surgical Technique**

A mucosal incision is made along the anterior border of the mandibular ramus. This is extended to the coronoid process and extended laterally up to the frst molar area and subperiosteally dissected to expose the sigmoid notch, inferior border, and the posterior border of the ramus. Two fbro-optic lit Bauer retractors (left and right) are used—one on the sigmoid notch and the other at the angle area to get excellent exposure of the ramus. An oscillating saw angled at 105° is used to do the osteotomy. The cut is made posterior to the ante lingula prominence and directed superiorly to the sigmoid notch and inferiorly to the mandibular angle.

If circummandibular wiring fxation is planned, the medial aspect of the ramus above the lingula is dissected subperiosteally to the posterior border. The width need only be enough to pass the wires.

Osteotomy, as in the extraoral approach, extends from the sigmoid notch to the inferior border behind the entry of the mandibular nerve. The intraoral vertical cut should be made no more than 5–7 mm anterior into the posterior border. This will be behind the mandibular foramen [53]. According to some, ante lingual prominence as a landmark is unpredictable [54].

**Fig. 68.20** Case of open bite managed by BSSO. (**a1**, **b1**) Preoperative pictures. (**a2**, **b2**) Postoperative pictures. (**c1**) Preoperative lateral cephalogram. (**c2**) Postoperative lateral cephalogram

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**Fig. 68.20** (continued)

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**Fig. 68.21** Displacement of the condyle due to torquing as demonstrated here in a vertical ramus osteotomy, is the most common reason for TMJ problems

For better access, as well as visibility and mobility of the fragments, the coronoid process can be separated using a reciprocating saw. The coronoid process is allowed to retract with the temporal muscle.

An appropriate retractor with a cup at the end can be held hooked to the posterior border, and the soft tissue is held retracted laterally. Care should be taken to orient the cut and also to prevent injury to the soft tissues.

After the osteotomy, the condylar segment is overlapped laterally over the mandible. Medial pterygoid attached to the medial aspect may be stripped in the anterior region of the segment to facilitate tension-free positioning of the condylar segment. The same osteotomy is performed on the opposite side, and intermaxillary fxation is maintained for 6 weeks. Extraoral approach for vertical subsigmoid osteotomy is advocated for large mandibular set back of greater than 10 mm [55, 56].

Over correcting the mandibular set back by 2 mm to provide compensation for relapse is also recommended [57]. The use of skeletal wire fxation seems to stabilize the initial movement, but does not infuence long-term relapse [58].

Ghali and Sikes have reported that IVRO improves TMJ functions and relieves TMJ symptoms more effectively when compared with SSRO, due to the fnal position of the condyle more anteriorly and inferiorly which

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**Fig. 68.22** Diagram for intraoral subsigmoid vertical osteotomy

results in an increased joint space and better disk-condyle relationship [59].

Raúl González-García described endoscopically assisted intraoral vertical ramus (IVRO) and subcondylar (ISCO) osteotomies for the treatment of symmetric mandibular prognathism. He claimed the use of saw and bone chisel under the continuous control of the endoscope provides a safer approach since the osteotomy is controlled during the whole process and provides complete visualization of the osteotomy site [60].

#### **Stabilization, Fixation, and Wound Closure**

Most surgeons use circummandibular or transosseous wires. Rigid internal fxation using plates is rather diffcult to place and carries greater risk of injury to the mandibular nerve. Lag screws or mini plates are sometimes used.

Intermaxillary fxation for a period of 6 weeks is advised, if rigid fxation is not used. Wound closure is done as in sagittal split, adhering to the basic principles.

#### **TMJ Considerations**

Radiographically there is an anterior downward and forward movement of the condyle after ramus osteotomy. However, there is a tendency to return to its preoperative position [61– 63]. Double contouring of the condyle after 6 months was reported which is attributed to condylar remodeling [64]. Remodeling of the glenoid fossa also has been documented [65]. Complications and their management are very much similar to those of sagittal split.

#### **68.5 Body Osteotomy of Mandible**

This was one of the earlier procedures used for mandibular prognathism. Blair reported a body osteotomy at the premolar level for mandibular prognathism in 1906 [19]. Since the advent of the ramus procedures, body osteotomy has lost its popularity. However, in certain conditions, body osteotomy may have to be resorted to.

#### **Surgical Procedure**

Depending on the site of osteotomy, soft tissue dissection varies. The basic principle is to refect the buccal mucoperiosteum down to the inferior border taking care not to injure the mental nerve, but at the same time, exposing it.

The next step is to remove the buccal cortical plate from the mental foramen region backward to behind the osteotomy/ostectomy site for release of the neurovascular bundle. The tooth at the osteotomy site is extracted.

Using a fssure bur, the outer cortical plate is marked and a window is cut. Using curettes and chisels, the cancellous bone around the neurovascular bundle is removed. The nerve is released using a nerve hook. Anterior continuation of the inferior alveolar nerve (the incisal branch) is severed. This helps in better retraction of the nerve. Continuation of the mental nerve is preserved. Mucoperiosteum on the lingual aspect is elevated and protected by a periosteal elevator. Osteotomy is completed adhering to the basic principles. The same procedure is repeated on the contralateral side. Body osteotomy at the molar level is almost outdated since the advent of sagittal split osteotomy.

Body osteotomy anterior to the mental foramen can be resorted to in certain specifc cases. The main indication of this procedure is lower dentoalveolar protrusion with anterior open bite. "V" osteotomy is done at the frst premolar region. This will not reduce the total mandibular length but rotates the anterior segment upward and backward. Maintenance of the arch and occlusion is important. Rigid fxation is mandatory as tendency for relapse is very high due to the pull exerted by the genioglossus and geniohyoid muscles (Fig. 68.23).

Stabilization is achieved by arch bars or by orthodontic means. Fixation using two plates (each plate having a minimum of 4 holes) on each side is advised.

#### 68 Orthognathic Surgery for Mandible

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**Fig. 68.23** Body osteotomy at the level of the premolar region. Diagrammatic representation

#### **68.6 Symphyseal Osteotomy**

Midline osteotomy is used either to narrow or to expand the mandible. Expansion is more diffcult than narrowing, due to tissue resistance. Before narrowing the mandible, a space must be created at the symphysis by extracting an anterior tooth (Fig. 68.24). Parasymphyseal step osteotomy approach with a hybrid mode of force application might be the most viable option for true mandibular arch expansion.

#### **68.7 Lower Anterior Subapical Osteotomy**

Hullihen performed the frst ever anterior subapical osteotomy and published it in 1849 [66]. This procedure was done for a girl who had sustained burns and had the anterior segment of the mandible got distracted anteriorly by the traction of the scar resulting in everted lip, protrusion of teeth, and open bite.

Hofer used anterior subapical osteotomy to advance anterior teeth for correction of mandibular dentoalveolar retrusion [67]. Kole used this technique to correct an anterior open bite.

Lower anterior subapical osteotomy is widely used in the following conditions:


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**Fig. 68.24** Midline osteotomy (Diagrammatic representation)

#### **Surgery**

Sulcus incision is made and the mucoperiosteal fap is refected. Subperiosteal tunneling is done at the lingual aspect of the planned osteotomy site. Extraction of tooth (usually the frst premolar) is done, if the intention is to retrude the dentoalveolar segment (Figs. 68.25a, b, c and 68.26a, b, c).

Osteotomy or ostectomy is done as planned. Stabilization and fxation are done in the preplanned position using prefabricated occlusal wafer splint or arch wires. Stabilization is done by using lag screws, position screws, or wires. Semi rigid bone plates are considered superior.

In cases where the anterior segment of the mandible is repositioned superiorly, a gap is created at the osteotomy site (subapically). Autogenous bone grafting is advised to fll this gap.

When the osteotomy is planned behind the mental foramen, the neurovascular bundle may be released from the mandibular canal and protected.

#### **68.8 Total Subapical Osteotomy Mandible**

Mcintosh in 1974 described total mandibular alveolar osteotomy. In 1942 Hofer [67] described horizontal osteotomy of mandible for horizontal defciency or excess and asymmetry.

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**Fig. 68.25** Lower anterior subapical osteotomy. (**a**) Diagrammatic representation. (**b**) Photograph demonstrating the vertical interdental and the horizontal connecting osteotomies. (**c**) Lower subapical osteotomy can also be combined with genioplasty

Total subapical osteotomy of the mandible is used mailly for the following indications:


Adequate bone should be present below the apices of the roots.

#### **Surgery (Fig. 68.27a, b, c)**

Mucoperiosteal fap is refected. The neurovascular bundle is released as described earlier (under "Body Osteotomy of Mandible"). Osteotomy is started behind the most posterior teeth. The cut is made using reciprocating saw or bur. Care should be taken not to damage the lingual tissues. Osteotomy is continued anteriorly, without injuring the released neurovascular bundle. About 4 mm of bone should be left below the apices of the teeth to ensure proper blood supply. The dentoalveolar segment is freed and mobilized. Preplanned

**Fig. 68.26** Protrusion anterior dentoalveolar segment of mandible treated by lower anterior subapical osteotomy. (**a1**, **b1**) Preoperative pictures. (**a2**, **b2**) Postoperative pictures. (**c1**) Preoperative lateral cephalogram. (**c2**) Postoperative lateral cephalogram

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#### **Fig. 68.26** (continued)

occlusion is established. Maxillomandibular fxation is aided by wafer splint. The neurovascular bundle is repositioned and secured in position using struts of bone [68].

Stabilization is done using rigid internal fxation. Postoperative sequelae are usually marked by edema which gets resolved in about 2 weeks. Sensory disturbances, though present, usually recover with time. Injury to the neurovascular bundle may cause permanent anesthesia.

Complications are usually rare. The importance of proper blood supply through the lingual pedicle is of utmost importance. This is mainly through the mylohyoid, genioglossus, and geniohyoid muscle attachments.

#### **68.9 Posterior Subapical Osteotomy Mandible** (Fig. 68.28)

The basic plan of the surgery is not very different from that of total subapical osteotomy. The incision is limited to the posterior area. The decompression of the neurovascular bundle is done, and the osteotomy is performed as described earlier.

The main indications are to shift the dentoalveolar segment in question to the required direction in all three dimensions of space, i.e., antero-posterior, vertical, or horizontal.

#### **68.10 Genioplasty**

Genioplasty is used for the correction of deformities of the chin. It is possible to reposition the chin in all the three dimensions of space. Hofer in 1942 introduced horizontal osteotomy of the symphysis [67]. By repositioning the inferior mandibular symphysis, a more stable and natural appearance can be attained [69].

#### **Surgical Procedure** (Fig. 68.29a, b) (Video 68.3)

Incision is made on the labial mucosa on the lower lip. It is extended from the premolar region to the opposite symmetrical site. The incision is taken to the periosteum, which is refected to expose the bone. Subperiosteal dissection is done to expose the inferior border of the mandible. Mental nerve is identifed and protected.

#### **Osteotomy/Ostectomy**

Bony cut is made on the chin about 4.5 mm below the apices of the teeth. The posterior end of the cut should taper to the inferior border, behind and below the mental foramen. (This prevents step defects at the site which may be manifested in the soft tissue also.) The segmented portion is freed from the rest of the mandible but remains pedicled to the digastric and geniohyoid. If the inferior segment is stripped off the periosteum, making it a free graft, intense infammatory reaction

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**Fig. 68.27** Total subapical osteotomy. (**a**) Neurovascular bundle is released. (**b**) Osteotomy is done using bur or saw. (**c**) The dentoalveolar segment is positioned and fxed rigidly.

and necrosis may occur [70, 71]. The degree of bone resorption and necrosis is indirectly proportional to the amount of pedicle attached to the segment [72].

For vertical reduction, another horizontal cut is made below the original cut, and the measured segment of bone between the two cuts is removed. It is not advisable to cut off the bone from the inferior border as this can imperil the normal contour of the chin. Unilateral vertical reduction/augmentation can be done for correction of asymmetry, since the chin can be moved in all three dimensions (Fig. 68.31a, b).

Increase in the height of the chin can be achieved by bone grafting (preferably autogenous) and rigid internal fxation using plates. Unilateral height increase can be done in asymmetry. However, high morbidity is associated with bone graft and alloplastic materials, such as recurrence, infection, and resorption [73]. Chin can be augmented (augmentation genioplasty) (Fig. 68.30a−c) by bringing the cut inferior segment anteriorly and fxing it by rigid fxation. For major advancement, stepwise augmentation, slicing the inferior border into more than one horizontal segment is advocated (Figs. 68.32 and 68.33a, b, c) (Also refer Fig. 78.42).

Retropositioning of the chin can also be done, but the soft tissue adaptation following posterior positioning of the chin is

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**Fig. 68.28** Posterior subapical osteotomy

not 100%. While positioning the inferior border posteriorly, the labiomental fold may get compromised (Fig. 68.34a, b).

Genioplasty can be used for widening and narrowing the chin in the horizontal direction. In mild mandibular asymmetry, the midpoint of the chin may be off the facial midline. By horizontal repositioning of the inferior border, the midpoint of the chin can be brought to the midline of the face, and the mandibular asymmetry can be camoufaged (Fig. 68.35).

Following surgery, the wound is closed adhering to the basic principles. Like in other osteotomies, 3–6 months are necessary for the lip to adapt to the new position and resume normal function. Complications are rare with this procedure. Wound dehiscence occurs in some cases. Meticulous irrigation and aseptic measures can reduce the chances of infection. Sensory loss for a period may be noticed due to traction on the mental nerve. Often sensation is regained within 3–6 months. Rigid fxation technique has reduced the chances shifting of position of the moved segment. Though the reported relapse rates vary in genioplasty, most authors agree that relapse occurs within the frst year [38, 70].

#### **68.11 Extended Genioplasty/Mandibular Basal Osteotomy**

Mandibular basal osteotomy is an innovative predictable technique for correction of defciency, excess, and/or asymmetry of the inferior mandibular border, decreasing morbidity, and many other complications of traditional bone grafts and alloplastic techniques [74].

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**Fig. 68.29** (**a**) Osteotomized chin can be moved in all the three dimensions. (**b**) Advancement genioplasty

**Fig. 68.30** Case of augmentation genioplasty. (**a1**, **b1**) Preoperative pictures. (**a2**, **b2**) Postoperative pictures. (**c1**) Preop lateral cephalogram. (**c2**) Post op lateral cephalogram

**Fig. 68.30** (continued)

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©Association of Oral and Maxillofacial Surgeons of India

**Fig. 68.31** Mild facial asymmetry can be corrected by bone grafting on one side, after osteotomy. (**a**) Pre-operative assessment and (**b**) treatment (osteotomy design)

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**Fig. 68.32** Major advancement of the chin can be effected by a double sliding genioplasty, which is a step osteotomy of the lower border

In extended genioplasty dissection and exposure of the chin, mental nerve and body of the mandible is recommended by a degloving incision. With complete dissection and mobilization of nerves, an extended osteotomy to the antegonial angle may be carried out (Fig. 68.36a, b). The basal osteotomy below the inferior alveolar canal ensures proper proportionality between the advanced segment and the posterior mandible [75]. By laterally sliding the lower border (extended lateral sliding genioplasty), facial asymmetry can be corrected. This procedure can be used for minimal to moderate hemifacial microsomia and facial deformity resulting from unilateral ankylosis of the temporomandibular joint [76] (Fig. 68.37a, b).

#### **68.12 Distraction Osteogenesis**

Distraction osteogenesis is a recent introduction into the feld of orthognathic surgery. This technique has revolutionized the possibilities of orthognathic surgery. It was Ilizarov, a Russian orthopedic surgeon, who popularized this technique. The frst team to report gradual distraction of human mandible was McCarthy et al. in 1992 [77]. As bone has got regenerative capabilities, it is possible to create new bone and lengthen the bone in a cut segment by slowly distracting it. The technique is very useful in the management of defciency of bone in the maxillofacial region as this is an excellent method to increase bone quantity. The spectrum of indications for distraction is widening and innovations are coming up in the feld rapidly. During distraction certain important principles are to be followed.

It is advisable to complete the osteotomy and mobilize the segment as far as possible and then put back the segment to its original position and distract it gradually. During distraction directional stability should be ensured, in order to counteract the pull of the soft tissue and the muscles [78]. A new terminology "distraction histogenesis" has come into vogue as not only the bone but the surrounding tissues also get lengthened. Geniohyoid muscle can be lengthened to a maximum of 20% of its resting length [79]. It is possible to distract the inferior alveolar nerve as well [80]. It is important that the distracted tissue is attached to vital tissue to maintain

**Fig. 68.33** Case of retruded chin corrected by double sliding advancement genioplasty. (**a1**, **b1**) Preoperative pictures. (**a2**, **b2**) Postoperative pictures. (**c1**) Preoperative lateral cephalogram. (**c2**) Postoperative lateral cephalogram

perfusion. Periosteum is rich in osteogenitor cells, and for callus distraction and bone lengthening, the periosteum should be intact, and hence it should be preserved [48].

After osteotomy a latency period of 4–7 days is advised to provide time for the soft tissue to heal. However other factors like age, stability of fxation, type of operative procedure that affects the formation process during the initial stages of distraction, etc. are to be considered before deciding on the latency period [81]. Certain other studies did not show any difference between no latency period and a latency period [82, 83].

Four stages are recognized in distraction osteogenesis— (a) fbrovascular hematoma formation, (b) formation of collagen fbers parallel to distraction vector, (c) bone formation and remodeling of new bone, and (d) formation of solid compact bone. In fast distraction collagen, fbers may lose contact, and bone formation may not take place. In slow

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**Fig. 68.33** (continued)

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**Fig. 68.34** Reduction of the chin can also be achieved. However, sharp margins are to be trimmed off. (**a**) Pre-operative planning and (**b**) treatment (osteotomy design)

distraction, consolidation of bone may occur earlier [84]. Karp et al. demonstrated that intramembranous ossifcation is what occurs predominantly [85]. Distraction of 1 mm per day is the widely accepted rate [86]. Direct current electrical stimulation may be useful in activation and consolidation

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**Fig. 68.35** Osteotomy plan for mild facial asymmetry pertaining to the chin

period [87–89]. Insuffcient distraction and defective vectors can compromise the fnal result. These complications can be, to some extent, managed by manipulating the regenerate bone by the application of orthodontic traction [79, 90–92]. OW and Cheung reported a lower incidence of persistent IAN disturbance (3%) after MDO compared with BSSO, of which the incidence was 28% [93]. In terms of skeletal stability in small to moderate advancements, there is no signifcant difference between BSSO and DO. DO requires a second surgery for removal of the distractor, which goes in favor of BSSO [94].

Distraction osteogenesis has got an important role in managing sleep apnea, in cases like micrognathia, Pierre Robin syndrome, hemifacial microsomia, Treacher Collins syndrome, etc. [4, 95]. Due to its complex nature, it is rather diffcult to treat unilateral craniofacial microsomia, in growing children. Maxilla, zygoma, mandible, external and middle ear, facial and trigeminal nerves, muscles of mastication, and overlying soft tissues are the structures of the frst and second arch which are involved [96] (Refer Chap. 78 on Hemifacial microsomia and Treacher Collins syndrome).

In severe cases, in neonatals, tracheostomy may become necessary. Mandibular distraction is an effective method in resolving upper airway obstruction and decannulation of tracheostomy [97–99]. Rachmiel A. et al. have reported an increase of mandibular volume by 28.4%, increase of upper airway volume

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**Fig. 68.36** After making a degloving incision an extended genioplasty may be done. it is possible to preserve the mental nerve. (**a**) Oblique view and (**b**) frontal view

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**Fig. 68.37** Major asymmetry of the mandible can be corrected to a great extent by extended lateral sliding genioplasty. (**a**) Pre-operative plan and (**b**) treatment (osteotomy design)

by 71.92%, and increase in oxygen saturation. This study was conducted in children between 13 months and 7 years of age [25] (refer Chap. 87 on distraction osteogenesis).

In severely hypoplastic mandible multi-stage correction starting from young age may be considered for functional and psychological reasons. Less severe cases may be taken up for single stage correction after the permanent dentition is erupted [100].

#### **68.13 Conclusion**

Mandible is a horse shoe-shaped bone hinged to the skull and performs the major function, chewing, and forms the lower part of the mouth which houses the tongue and other musculature. All the muscles of mastication and many other muscles of facial expression are attached to the mandible. Hence mandible is an important structure in both function and aesthetics. Different osteotomies of mandible can move the jaw in almost all the three directions and change the size and shape of the jaw and face to achieve better function and aesthetics. This chapter is intended to elucidate various osteotomy techniques on the mandible.

Disclosure Authors have no fnancial conficts to disclose.

#### **68.14 Case Scenarios**

**Case 1** (Fig. 68.38a, b, c)

Patient aged 22 years, female, reported with complaint of facial deformity with a history of fall when she was about 8 years old. No deformity was noticed, and no treatment was taken at that time, and as she grew up, she started developing deviation of the face.

On examination she had facial asymmetry with deviation of the jaw to left side. She had class II occlusion and defcient chin. Radiographs revealed under developed and deformed condyle on the left side. The mandible was shifted to the left side due to underdevelopment of the mandible on left side (Fig. 68.38a1, b1, c1).

Treatment: Pre-surgical orthodontic treatment with sagittal split osteotomy and extended lateral sliding genioplasty with rib bone grafting on right side.

Postoperative pictures after 1 year (Fig. 68.38a2, b2, c2).

#### **Case 2** (Fig. 68.19a, b, c)

Patient aged 19 years reported with complaint of protruded teeth and facial deviation with no relevant history.

On examination, she had vertical maxillary excess with mandibular prognathism. Other clinical fndings included incompetent lips, convex facial profle, acute nasolabial angle, and facial asymmetry with deviation of chin toward right side. Radiographs revealed vertical and anterioposterior maxillary excess with mandibular prognathism and defcient chin.

Preoperative pictures (Fig. 68.19a1, b1, c1)

Treatment plan: Pre-surgical othodontic treatment followed by surgery.

Surgery: LeFort 1, anterior maxillary osteotomy, bilateral sagittal split osteotomy, and genioplasty were done for the patient under general anesthesia.

Postoperative pictures after 1 year (Fig. 68.19a2, b2, c2)

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**Fig. 68.38** Mandibular asymmetry corrected by extended lateral sliding genioplasty. (**a1)** pre operative frontal view. (**a2)** post operative frontal view. (**b1, b2)** pre and post operative Frontal cephalogram. (**c1, c2)** pre and post operative lateral cephalogram

#### **References**


mandibular advancement: a three-dimensional analysis. Int J Oral Maxillofac Surg. 2016;45:787–92.


illary expansion (SDRME) a review of the literature. Int J Oral Maxillofac Surg. 2005;34:709–14.


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## **Orthognathic Surgery for the Maxilla-LeFort I and Anterior Maxillary Osteotomy**

**69**

Ashok Dabir and Jayesh Vahanwala

#### **69.1 History of Maxillary Osteotomies**

*Maxillary Osteotomies*

*One does not know a science completely without knowing its history.*

Auguste Comte (1798–1857) [1]

#### **The Le Fort I-Type Maxillary Osteotomy**

The development of modern maxillary orthognathic surgical procedures had diverse historical origins and contributions. The removal of nasal and nasopharyngeal polyps via hemi maxillary osteotomy was being undertaken in Europe in the mid-nineteenth century, notably by the German surgeon Bernhard Rudolf Konrad von Langenbeck (1810–1887) in Berlin [2]. The frst maxillary procedure that would today be described as a total Le Fort I-type osteotomy appears to have been undertaken in 1868 by the American surgeon, David Williams Cheever (1831–1915) in Boston City Hospital to provide surgical access for removal of a large nasopharyngeal polyp [3]. One year prior to this, in 1867, Cheever had undertaken a down-fracture of the right hemimaxilla for similar surgical access in another patient, who had made a complete recovery [4]. The total down-fracture of the maxilla at the Le Fort I level performed in 1868, described as Cheever's "double operation," though technically successful, had an unfortunate postoperative outcome in that the patient subsequently died 5 days later, though probably not as a direct result of the maxillary procedure [5, 6].

In 1901, a French surgeon from Lille named René Le Fort (1869–1951) conducted experiments using blunt trauma to intact cadaveric faces, from different directions and varying magnitudes, and thereby described the natural planes of maxillary and facial fractures [7, 8] now known as the Le Fort classifcation of facial fractures. The names of the Le Fort I-, II-, and III-type osteotomies are due to their similarity to the Le Fort fractures.

In 1927, Wassmund carried out a maxillary osteotomy at the Le Fort I level, without pterygoid plate disjunction or mobilization at the time of surgery [9]. He used elastics to close an anterior open bite, without placing a bone graft, which subsequently relapsed. In 1934, Axhausen in Berlin described advancement of the maxilla at the Le Fort I level, which was incompletely mobilized, again with postoperative elastic traction [10].

Wassmund was the frst to apply osteotomies at the Le Fort I level for correction of midfacial deformities [11]. The technique was subsequently modifed by several surgeons including Axhausen [12], Schuchardt [13], and Willmar [14]. In 1965, Obwegeser improved the precision of the Le Fort I osteotomy by suggesting complete mobilization of the maxilla so that repositioning was achieved without tension [15, 16]. The operation was slow to gain popularity until 1973, till Bell's description of the remarkably resilient maxillary blood supply [17]. With advancement in technique and the introduction of safe hypotensive anesthesia, the Le Fort I osteotomy has been increasingly utilized over the last four decades. Over the years, various modifcations of the osteotomies, ORIF methods and bone grafting to the mobilized maxilla, have continued to evolve and progress.

#### **69.2 Surgical Anatomy**

The paired maxillae are made up of a body and four projections: frontal, zygomatic, palatine, and the alveolar process. The maxilla forms the inferior and medial borders of the

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_69) contains supplementary material, which is available to authorized users.

A. Dabir (\*)

D. Y. Patil University School of Dentistry, Nerul, Navi Mumbai, India

Breach Candy Hospital, Mumbai, India

J. Vahanwala (\*) Department of Oral Surgery, Vaidik Dental College and Research Centre, Nani Daman, Daman, India

Breach Candy Hospital, Mumbai, India

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_69

orbits. The infraorbital foramen is located at an average distance of 7.8 mm, positioned inferiorly to the infraorbital rim in women and 8.5 mm in men [18]. The vascular and sensory supplies to the cheek, lateral aspect of the nose, and upper lip exit the bone from this foramen.

The anterior alveolar processes surround the piriform apertures and join to form the anterior nasal spine in the midline. The anterior nasal spine is the most anterior inferior attachment for the cartilaginous nasal septum, which extends posteriorly along the nasal crest and articulates with the vomer.

The maxillary sinuses are housed in body of maxilla. Anteriorly, palatine process of each maxilla and posteriorly, horizontal lamina of palatine bone form the hard palate. The greater palatine foramen is located on each side approximately 10 mm posteromedial to the second molar.

The nasolacrimal duct travels within the bony wall between the nasal cavity and the maxillary sinus before terminating below the inferior turbinate. It can be injured during the Le Fort I osteotomy or during an inferior turbinectomy performed to allow superior repositioning of the maxilla (Fig. 69.1) [19, 20].

Posterolaterally, the maxilla articulates with the pyramidal processes of the palatine bones and the pterygoid plates of the sphenoid bone. This pterygomaxillary junction extends superiorly as a fssure, which ends at the pterygopalatine fossa. The terminal portion of the internal maxillary artery traverses the pterygopalatine fossa and gives off several branches that can be encountered during a Le Fort I osteotomy (Fig. 69.2a, b). The average distance between the infe-

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**Fig. 69.1** Relationship of the nasolacrimal duct to the Le Fort I osteotomy cut. The meatus of the nasolacrimal duct is unlikely to be injured if the osteotomy is made just beneath the infraorbital foramen and into the piriform rim at the level of the inferior turbinate (IT). *MT* middle turbinate

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**Fig. 69.2** (**a**) Branches of external carotid artery, (**b**) terminal branches of internal maxillary artery

rior extent of the pterygomaxillary junction and the posterior superior alveolar artery is 15 mm, the infraorbital artery is 32 mm, and the descending palatine artery is 25 mm. The descending palatine arteries travel through the perpendicular plate of the palatine bones and are located approximately 34 mm posterior to the piriform rims and within 10 mm medial to the pterygomaxillary fssures [21].

Osteotomies of the lateral nasal walls and at the pterygomaxillary fssures must be completed carefully to avoid injuring these vessels. The internal maxillary artery is 23–25 mm above the base of the junction of the maxilla with the pterygoid plates, with an average diameter of 2.5 mm. In addition to the direct vascular supply of the maxilla by the descending palatine arteries, there is a rich collateral vascular network from the soft palate supplied by the ascending pharyngeal arteries and the ascending palatine branches of the facial arteries (Fig. 69.3). The risk of damaging the artery can be minimized by ensuring the pterygoid osteotome is directed downward toward the palate and is less than 1.5 cm above the inferior part of the fssure [22, 23].

Bell's work revealed that ligation of the bilateral descending palatine arteries does not compromise the vascularity of the maxilla as long as the soft palate pedicle is preserved [24, 25].

The pterygoid plexus of veins is located between the temporalis and lateral pterygoid muscles and between the medial and lateral pterygoid muscles. It receives tributaries corresponding to the branches of the maxillary artery and drains into the maxillary vein. Venous bleeding from this plexus may be encountered during the posterolateral maxillary dissection and pterygomaxillary disjunction.

The risk of damaging the artery can be minimized by ensuring the pterygoid osteotome is directed downwards towards the palate and is less than 1.5 cm above the inferior part of the fssure [22, 23].

Bell's work revealed that ligation of the bilateral descending palatine arteries does not compromise the vascularity of the maxilla as long as the soft palate pedicle is preserved [24, 25].

S. Bruneder et al. studied a special type of arterial variation of the Le Fort I segment's blood supply. Individuals with this special arterial anatomy may clinically be at high risk for hypoperfusion and avascular segment necrosis after surgery. Individualized operation planning that takes the patient's arterial anatomy into consideration may help to prevent ischemic vascular complications of the Le Fort I segment and improve operative outcomes in at-risk patients [26].

S. Salmanet et al. studied Dynamic analysis of maxillary perfusion during Le Fort I osteotomy using indocyanine green and concluded that there was a statistically signifcant decrease in perfusion, as assessed by intraoperative dynamic angiography, to the anterior maxilla following maxillary down-fracture. Patient age, conventional versus segmental Le Fort I osteotomy, changes in mean arterial pressure and/or heart rate, and preservation of the descending palatine vessels had no statistically signifcant effect on perfusion [27].

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The patient's sex and aspects of the skeletal and craniofacial pattern have an infuence on the pterygomaxillary area and descending palatine canal anatomy. A preoperative computed tomography analysis involving this evaluation could reduce the risk of surgical complications. A preoperative CT analysis should be performed on an individual basis and should identify the differences between the two sides in the same patient to allow a safer surgical procedure during Le Fort I osteotomy [28].

#### **69.3 The Anterior Segmental Maxillary Osteotomy**

The frst anterior segmental maxillary osteotomy (ASMO) was reported at the beginning of the twentieth century by Günther Cohn-Stock [29], wherein he tried to surgically "correct a marked overjet and overbite of the central maxillary teeth." In his pioneering article in 1921, he described the evolution of his idea to perform an osteotomy of the anterior segment of the maxilla while preserving the vestibular pedicle and, in a later design, also the palatal artery [29].

After Cohn-Stock's original report, three variations of the procedure were developed by Wassmund [9], Wunderer [30], and Cupar [31]. These variations were designed to maintain suffcient blood supply to the maxilla while giving adequate access for instrumentation [32, 33].

In 1927 Wassmund [9] improved Cohn-Stock's design by creating a direct approach to the labial premaxillary cortex using three vertical incisions and subperiosteal tunnelling for completion of the labial osteotomy without refection of labial or palatal faps. Both the labial and palatal blood supply are maintained; however, the osteotomy is made in a relatively blind fashion. This method may be indicated for closure of multiple interdental spaces [33] and for anteroposterior repositioning of the premaxilla [34]. It was found to maintain the best vascularity of the repositioned segment in comparison to all other ASMO methods [35].

In 1954 Cupar [31] described a different approach for down-fracture of the anterior maxilla: exposure of the labial aspect of the maxillary bone by a vestibular circumferential cut and labial fap to facilitate the labial osteotomy under direct vision. A palatal osteotomy was performed through a tunnel, maintaining the palatal blood supply. This technique is indicated for superior repositioning of the anterior maxilla in cases of vertical maxillary excess.

In 1963 Wunderer [30] advocated refection of a palatal fap without fracturing of the anterior maxilla and maintenance of the labial blood supply. Direct access for the palatal osteotomy is the main advantage of this technique, especially if posterior segments of the premaxilla must be removed.

Therefore, this technique may be indicated for setback of the anterior part of the maxilla. Blood fow studies have demonstrated that the transpalatal approach causes the greatest decrease in blood supply to the anterior maxilla [36]. However, transpalatal soft tissue incision and labial osteotomies impair vascular supply to the anterior maxilla from the greater palatine vessels and the superior alveolar vessels, respectively, leaving the labial collaterals as the sole blood supply to the anterior maxilla [37].

In 1977 Epker modifed the Cupar technique for downfracture of the anterior maxilla. He used only labial faps and vertical tunnels labial to the teeth to be extracted, which were usually premolars on both sides [38]. Epker's modifcation enables repositioning of the anterior maxilla superiorly, posteriorly, and inferiorly. The main advantages of the Epker modifcation include preservation of the palatal pedicle, ease of placement of internal fxation, provide access to the nasal septal structures to prevent buckling of the nasal septum with superior repositioning of the maxilla, and a direct approach for removal of palatal bone. When required, bone grafting for stabilization of an inferiorly positioned anterior maxilla may also be done using this method.

The segmental Le Fort I osteotomy should not be excluded from the technical armamentarium in orthognathic surgery. On the contrary, the literature consulted suggests it to be a useful tool for the three-dimensional surgical correction of maxillary malposition [39].

#### **69.3.1 Technique** (Video 69.1)

Anaesthetic and Positioning Considerations: Controlled hypotensive anesthesia has been shown to reduce bleeding from mucosal and bone edges that contain a rich network of small vessels, which cannot easily be identifed and controlled with surgical techniques. In healthy patients, a reduction in mean arterial pressure (MAP) of 30% below the patient's baseline with a minimum MAP of 50 mmHg is safe [40]. In bimaxillary surgery, postoperative blood transfusions are necessary in 13–48% of patients who do not have controlled hypotension during the operation [41, 42]. The need for transfusion has been nearly eliminated by using this technique. Placement of an indwelling bladder catheter for intraoperative monitoring of urine output as a marker of renal perfusion should be considered when using controlled hypotension. After induction of general anesthesia, the patient is nasally intubated. Because intraoperative maxillomandibular fxation is essential to establish the postoperative position of the anterior maxilla, oral intubation is less desirable and should be avoided. The endotracheal tube must be suffciently below the level of the vocal cords to prevent unintended dislodgement during premaxillary manipulation. A shoulder roll is inserted to extend the neck without creating hyperextension. A sterile preparation and draping is performed, leaving the orbits and nasion exposed. After the planned mucosal incision is marked, local anaesthetic with vasoconstrictor (lidocaine with 1:100,000 epinephrine) is infltrated in the labial sulcus. Palatal injection should be avoided so as not to induce vasoconstriction in the palatal pedicle.

#### **69.3.2 Exposure**

A horizontal buccal sulcus incision is made by diathermy or a #15 scalpel blade in one strike to the bone in the deepest section of the buccal vestibule, circumferentially from right to left second premolar. Next, the periosteum is refected superiorly to expose the entire canine fossa and piriform aperture bilaterally. Inferiorly, minimum mucoperiosteal stripping should be done, to maximize blood supply to the osteotomized maxilla. The alveolar mucoperiosteum should be undermined to the crestal bone only at preplanned osteotomy or ostectomy sites. The nasal mucoperiosteum should be carefully separated from the nasal cavity foor to prevent intraoperative bleeding, postoperative oronasal communication, and fstula formation. The cartilaginous nasal septum is separated from the nasal groove of the maxilla to facilitate its manipulation later.

#### **69.3.3 Extractions and Horizontal Osteotomies**

As per surgical plan, maxillary premolars are extracted on each side. Then, a reciprocating saw or piezo-surgical saw is used to perform horizontal osteotomies. These bone cuts should run posteriorly from each side of the piriform rim, including the lateral maxillary walls and the lateral nasal cavity walls. The nasal mucosa is protected with a curved periosteal elevator. Due care should be taken to avoid injury to the infraorbital nerve during retraction of the upper mucoperiosteal fap. The posterior limit for these osteotomies is the planned vertical osteotomy/ostectomy, usually the frst or second premolar (Fig. 69.4a−d).

Figure 69.4b and Fig. 69.5 indicates the horizontal and vertical osteotomies/ostectomies that are performed using a #701 bur, mini-saw, or piezo. Precise bone removal should be done to ensure an accurate postoperative position and suffcient intersegmental bony contacts.

Meticulous tissue handling is of paramount importance at this stage. Failure to preserve buccal mucosa may lead to an impaired blood supply to the down-fractured maxilla or establishment of an oroantral fstula, in addition to periodontal compromise of the adjacent teeth.

#### **69.3.4 Final Osteotomy and Down-Fracture of the Premaxilla**

After completion of the planned osteotomies and ostectomies under direct visualization, the fnal osteotomy is done using an osteotome. Neither a palatal incision nor a mucosal undermining is done at this stage. A palpating fnger is positioned on the palatal mucosa, and the transpalatal osteotomy is completed with an osteotome. Down-fracture of the premaxilla is accomplished with a bone hook. Additional transpalatal and nasal ostectomies may be necessary at this stage and should be fnalized under direct access gained to the nasal aspect of the down-fractured premaxilla. Careful separation of the mucoperiosteum from the posterior segment of the palate facilitates setback of the anterior segment and prevents it from becoming detached from the anterior segment, compromising the blood supply (Fig. 69.6a, b).

#### **69.3.5 Midpalatal Osteotomy**

If indicated for transverse widening or narrowing of the premaxilla or closure of a diastema, a midpalatal osteotomy is performed with an osteotome or piezo-surgical saw (Fig. 69.7a, b).

#### **69.3.6 Fixation**

After completion of the ostectomies, maxillary teeth are placed into a preformed acrylic occlusal wafer, which is wired to the maxillary dentition. Temporary maxillomandibular fxation then is done, and a standard 1.5 or 2.0 maxillary plating system is used at the maxillary buttresses to fxate the bone segments in their planned postoperative position (Fig. 69.8a–c).

#### **69.3.7 Closure**

After thorough irrigation of the surgical site with saline, the mucosal incisions are closed with 3-0/4-0 vicryl suture. If indicated, alar cinch and V-Y closure of the buccal incision are performed at this stage. Maxillomandibular fxation is removed at the end of the procedure. The maxillary surgical wafer may be kept in place for 6 weeks for additional stability of the maxillary segments and occlusal guidance (Fig. 69.9a, b).

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**Fig. 69.4** (**a−d**) Epker's modifcaiton of Cupar's down-fracture anterior maxillary osteotomy. (**a**) Anterior maxillary excess with frst premolar to be extracted, not bonded othodontically, (**b**) vestibular incision (5 mm superior to mucogingival junction). Osteotomy marked, which includes a horizontal cut beginning at the pyriform rim, going lateral above the apices of the anterior teeth and vertical cuts to complete the bone removal at the site of the extraacted premolar, (**c**, **d**) Osteotomy marking with autoclaved pencil and cuts for anterior maxillary segmental osteotomy. (see Fig. 69.10a2 for clinical profle view)

#### **69.4 Le Fort I Osteotomy**

#### **69.4.1 Operative Technique** (Video 69.2)

There are many acceptable modifcations to the Le Fort I osteotomy, and the sequence of steps may vary from surgeon to surgeon. Figures 69.10a, b and 69.11a, b demonstrate a patient who has undergone a Lefort 1 with anterior maxillary osteotomy and mandibular subapical osteotomy for addressing her Vertical Maxillary Excess and dento-alveolar protrusion. The following is a description of the authors' preferred approach.

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**Fig. 69.5** Horizontal and Vertical Osteotomy Cuts (5 mm superior to mucogingival junction) Osteotomy marked, Horizontal cut 5 mm above the canine root tip, Vertical osteotomy marked approximate mesiodistal width of premolar

Anaesthetic and Positioning Considerations:

Anaesthetic and positioning considerations must be followed as previously discussed in the anterior segmental maxillary osteotomy technique.

#### **69.4.2 External Reference Marker**

An external reference marker is placed at the nasion to facilitate proper positioning of the maxilla in the vertical plane (Fig. 69.12a). Common techniques include insertion of a Kirschner wire or a bone fxation screw. Less invasive methods include marking with a skin scribe, a suture or tape, but these may be less reproducible due to skin mobility at the site. Occasionally a soft tissue landmark such as the medial canthus can also be used as a guide to measure from the incisal edge of the anterior teeth (Fig. 69.12b)

External reference points have been shown to be superior to internal references (lines or burr holes placed on the maxilla above and below the osteotomy), which are prone to inaccuracy due to the complex three-dimensional movement of the maxilla [43, 44]. Preoperative measurements are then obtained from the reference site to reproducible midline and lateral maxillary landmarks, typically the maxillary dental midline and the bilateral canine cusp tips or orthodontic brackets.

#### **69.4.3 Surgical Exposure**

Local anesthesia with vasoconstrictor is infltrated labially and buccally from the pterygoid plate region, forward to the midline bilaterally. A full-thickness mucosal and periosteal

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**Fig. 69.6** (**a**, **b**) Final palatal bone cut with osteotome, palatal mucosa protected with non-dominant hand for tactile sensation

**Fig. 69.7** (**a**) Down-fracture anterior segment of maxilla and maintaining palatal mucosa. (**b**) Midline or paramidline osteotomy for horizontal movement

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**Fig. 69.8** (**a**–**c**) Maxillary plating system used at the maxillary buttresses and pyriform region to fxate the bone segments in their planned postoperative position in case of Le Fort I with AMO, (**b**) right side (**c**) left side

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**Fig. 69.10** (**a**, **b**) (**a1, a2, a3**) Pre-surgical images of the patient. (**b1, b2, b3**) Post Le Fort I and anterior maxillary osteotomy images of the patient

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**Fig. 69.11** (**a**, **b**) Intra oral photos of the same patient as in Fig. 69.10. (**a1, a2, a3**) Pre-surgical images of the occlusion. (**b1, b2, b3**) Post anterior maxillary osteotomy images of the occlusion. A mandibular sub-apical osteotomy was also done for this patient (**b2, b3**)

incision is made in the soft tissue extending from the buttress of the zygoma on the either side, 3–4 m above the mucogingival junction with attention in the midline to a V-shaped incision to allow for aesthetic closure [45, 46] (Fig. 69.13). The incision can be made with a scalpel or electrocautery Colorado needle. While layered incisions serve no advantage for the dissection, electrocautery seems to control some hemorrhage at the time of the incision.

Retraction is maintained with down-turned Obwegeser retractors, and the superior mucoperiosteal fap is elevated with a #9 Molt periosteal elevator. The anterior nasal spine, piriform rim, infraorbital foramen, lateral maxillary wall, and zygomaticomaxillary junction are exposed. Exposure of the posterior maxillary wall and pterygomaxillary junction is next performed with a Molt periosteal elevator, placed parallel to the maxillary teeth and advanced posteriorly below

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**Fig. 69.12** (**a**, **b**) (**a**) External reference marker (skeletal landmark). A stable extraoral reference point is established with a 0.035-inch K-wire placed in the nasion. A caliper is used to measure the vertical distance from the K-wire to the brackets of the central incisor teeth, and these measurements are recorded. (**b**) A extraoral reference point at medial canthal (soft tissue landmark). A caliper is used to measure the vertical distance from medial canthal to the brackets of the central incisor teeth

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**Fig. 69.13** Maintain a small inverted "V" shape over the midline frenum, with the lateral extension of the incision being 5mm above the muco-gingival junction, from frst molar one side to the other

periosteum until the pterygomaxillary junction is encountered. The periosteal elevator on the bone and in a subperiosteal plane is maintained with angulation as it proceeds posteriorly to incline inferiorly or toward the hamular process of the sphenoid bone. This alleviates the potential problem of entering the pterygomaxillary fssure and concomitant increased hemorrhage [23, 47].

The nasal/septal mucosal dissection is performed after the bilateral maxillary osteotomies have been completed and involves elevation of the nasal mucosa with a curved freer elevator to the posterior palatine bone (Fig. 69.14).

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**Fig. 69.14** Exposure of the maxilla is achieved with a full horizontal vestibular incision superior to the mucogingival junction. With appropriate retraction, the infraorbital nerves, piriform rims, posterior maxilla, and anterior nasal spine will be identifed

As may be preferred by some surgeons, reference marks are placed vertically in the lateral wall of the maxilla, or bone reference holes are placed a standardized distance apart (15 mm seems to be a reasonable distance) vertically in the buttress and in the pyriform rim region (Fig. 69.15) [48–50].

Alternatively, a non-threaded Kirschner wire or Steinmann pin is placed in the nasal dorsum, and a reference measurement is taken from that Kirschner wire to the anterior dentition to allow for determination of the amount of superior repositioning of the anterior maxilla [51, 52].

With the use of a Tessier caliper, the vertical distance (height) between the medial canthus and the mid-maxillary incisor crown is measured on the left and right sides and recorded; this generally measures between 55 and 70 mm

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**Fig. 69.15** Marking of osteotomy cuts, horizontal cut minimum of 5 mm above the apices of the teeth, step or sloping downward and backward toward to maxillary pterygoid plates or Le Fort I level with stepladder cut

(Fig. 69.12). This is a reproducible relative measure of the anterior vertical maxillary height [53].

#### **69.4.4 Bony Osteotomies**

#### **69.4.4.1 Lateral Osteotomies**

A 701 straight fssure bur or reciprocating saw creates the lateral maxillary osteotomy from the lateral nasal rim to the zygomaticomaxillary junction. The osteotomy starts 3–4 m above the nasal foor and is carried to the depth of the maxillary sinus, back to the pterygomaxillary junction, approximately 30–35 mm above the bracket on the frst molar tooth. Cuts are made at least 5 mm above the roots of the teeth and can be made higher as needed. A vertical step at the frst molar is carried inferiorly for 5–10 mm (step osteotomy permits grafting in the zygomaticomaxillary buttress area subsequently, if required) [54], and then it is continued in a horizontal plane to the posterior maxilla ending in front of the pterygomaxillary junction (Fig. 69.16a, b).

#### **69.4.4.2 Pterygoid Plate Separation**

A 6- to 8-mm-wide, curved osteotome is placed in the pterygomaxillary junction, with the leading edge angled inferior, medial, and anterior. It is positioned in the junction with the horizontal osteotomy centered over the middle of the osteotome.

A fnger can be placed palatally at the junction of the hamulus with the tuberosity, and the mallet is used to drive the chisel through the junction. The end of the osteotome should be palpated on the palatal side as it comes through the junction, but it should not penetrate through

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**Fig. 69.16** (**a**, **b**) (**a**) The lateral maxillary wall osteotomy is carried posteriorly from the piriform rim to the pterygomaxillary junction, (**b**) with a vertical step ladder cut in the frst molar region. The osteotomy is placed at least 5 mm superior to the root apices

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**Fig. 69.17** A curved osteotome is placed in the pterygomaxillary junction, with the superior edge of the osteotome just above the horizontal osteotomy. A fnger is placed on the palatal side of the junction, and the osteotome is gently tapped through the junction until palpated on the palatal side, without perforating the soft tissue

the palatal tissue. There should be minimal resistance to separation, and if signifcant resistance is encountered, the osteotome position should be evaluated and repositioned (Fig. 69.17).

The scientifc literature cites examples of damage to the cranial nerves during the Le Fort I osteotomy [55–58].

#### **69.4.4.3 Lateral Nasal Wall and Septal Osteotomies**

A small safe-sided osteotome initiates the lateral nasal osteotomy at the piriform rim in the anterior extension of the lateral maxillary osteotomy. A mallet drives the osteotome posterior, parallel to the nasal foor, below the inferior turbinate. One must take care not to go beyond 25 and 30 mm in depth during osteotomy. The lateral nasal wall diverges (widens) posteriorly, and the osteotome must follow that divergence. Minimal resistance will be encountered until the pyramidal process of the palatine bone is encountered. At this resistance point, the osteotome can be driven another few millimeters to infuence the fracture plane through this structure during down-fracture (Fig. 69.18). The nasal septum osteotomy is next performed with a guarded U-shaped osteotome. The osteotome is introduced at the top of the nasal spine and is driven inferiorly and posteriorly along the nasal foor to separate the maxilla and palatine bone from the septum (Fig. 69.19).

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**Fig. 69.18** The lateral nasal wall osteotomy is completed from the inferior piriform rim to the anterior portion of the pyramidal process of the palatine bone. Care is taken to avoid a complete osteotomy through the pyramidal process in order to prevent injury to the greater palatine artery and nerve. The right maxilla has been removed to show the desired cross-section clearly

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**Fig. 69.19** The septal osteotomy is completed from the anterior nasal spine through the vomer bone posteriorly, with the guarded prongs on the septal osteotome angled inferiorly. Care is taken to retract the nasal mucosa to minimize injury and bleeding to the soft tissue. The right maxilla has been removed to show the desired cross-section clearly

#### **69.4.5 Down-Fracture and Mobilization**

Once the osteotomy cuts have been completed, some mobility should be readily evident, and down-fracturing be easily

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 69.20** (**a**, **b**) (**a**) Once the maxilla is mobilized, the nasal mucosa can be completely freed from the maxilla in the piriform rim region, (**b**)

The greater palatine nerve and artery can be visualized and protected

during posterior bone removal from the lateral nasal wall area (yellow arrows) (also see Fig. 65.12a)

done with either bilateral manual digital pressure in the canine fossa or with instrumentation support at the piriform rim. Slowly separate the maxilla by pulling the anterior portion inferiorly while observing the nasal mucosa to avoid tears. If signifcant resistance is encountered, revise the osteotomy cuts thoroughly to ensure complete separation. To avoid complications related to pterygomaxillary disjunction, we prefer to extract maxillary third molar and make a vertical osteotomy cut through the socket connecting the horizontal cut on the posterolateral surface of maxilla.

Precious et al. (1991) did a study of 138 consecutive Le Fort I osteotomies with successful down-fracture of the maxilla by digital pressure alone (with no serious complications except transient epistaxis that responded to local packing) [59, 60].

Once the down-fracture is completed, place a Seldin elevator or tongue depressor behind the tuberosity, and pull the posterior maxilla forward. This will fully mobilize the maxilla from its attachments. For large advancements, freeing the tissue from the nasal side of the posterior maxilla in the soft palate area will provide signifcantly more forward mobility. In addition, in repeat maxillary surgery, mobilizing the maxilla will most likely be more diffcult, and time must be spent freeing hard and soft tissue attachments to ensure passive movements and surgical stability.

#### **69.4.6 Removal of Posterior Interferences**

Removal of posterior interferences should be done immediately after down-fracture which will make it easier to set the maxillary position later. The maxillary bony septum is reduced most easily with a bur. The lateral nasal wall can be reduced with a rongeur, bur, or reciprocating saw. While protecting the descending palatine nerve and artery with a curved freer (Fig. 69.20a, b), the pyramidal process of palatine bone is most safely reduced with the reciprocating saw or bone fle. Sometimes a thin spatula osteotome can be used. Finally, the posterior tuberosity, anterior pterygoid plate, and posterior lateral maxillary wall can be reduced with a bur or reciprocating saw (Fig. 69.21). If the superior movement of the maxillary is more that 6 or 7 mm, a partial inferior turbinectomy may be indicated to allow a passive impaction. The nasal mucosa is incised with a scalpel blade along its inferior surface in an anterior-posterior direction. The inferior half of the turbinate is grasped with a large curved hemostat, and a dean scissor is used to excise this portion. Complete removal of the inferior turbinate is rarely necessary and can result in unpleasant clinical side effects. Electrocautery is used to coagulate the incised edge of the turbinate to minimize bleeding. The nasal mucosa is then sutured with a running 4-0 vicryl suture.

#### **69.4.7 Placement of Surgical Guide**

A prepared surgical guide is necessary to ensure accurate positioning of the maxilla. The guide is generally ligated to the upper teeth with 26–28 gauge wire. The upper and lower teeth are then wired together with 26–28 gauge wire, elastics, or power chain (Fig. 69.22).

#### **69.4.8 Removal of Anterior Interferences**

With the maxilla now fxed to the mandible, it is rotated into position by applying posterior and superior pressure on the

**Fig. 69.21** Posterior interferences are initially removed from the posterior septum, lateral nasal walls, pyramidal processes of the palatine bones, and lateral maxillary walls. This allows for passive seating of the maxilla without posterior pivoting

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**Fig. 69.22** Placement of surgical guide and achieve desire stable occlusion. The lefort I osteotomy and AMO cuts are visible

mandible. To properly rotate the mandible, the surgeon places two fngers at the gonial notch regions of the mandible and the thumb of the same hand at the chin. Upward pressure is exerted with the two fngers at the gonial notches, and the thumb exerts a posterior and downward pressure. This "triangular" fnger formation ensures full seating of the condyles during mandible rotation and maxillary positioning. The surgeon then rotates the mandible and maxilla upward, keeping pressure on the two fngers and thumb (Fig. 69.38a–c). Upward rotation is

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**Fig. 69.23** The maxilla is rotated into place and anterior interferences are removed to ensure full seating of the condyles at the desired vertical position. Seating of the condyles of the mandible is achieved with superior pressure at the gonial notches and posterior pressure at the chin. Once the correct vertical maxillary positioning is achieved, the mandibular-maxillary complex can be reproducibly rotated with the condyles in the fossa without any bone or soft tissue pre maturities (Also see Fig. 69.12a, b)

stopped as soon as the frst contact is detected, and this interference is reduced accordingly. Anterior interferences can be easily reduced with a bur. The caliper is used to check the vertical distance from the anterior brackets to the K-wire and interferences are reduced accordingly. Closely observe the nasal septum for early inferences and deviation. When all the bony interferences have been completely removed, utilizing the "triangular" fnger formation, the mandible and maxilla can be easily rotated up into a stable reproducible position, with the condyles fully seated (Fig. 69.23).

#### **69.4.9 Fixation, Grafts, and Final Measurements**

With the maxilla positioned, four miniplates are accurately bent to passively ft across the osteotomy in the piriform and anterior buttress areas of the maxilla. Typically, there are two fxation holes above and below the osteotomy in each bone plate, for placement of four screws. Thin bone or large bone gaps may require more fxation screws in each plate or even require additional plates. Bone grafts can be adapted into the 1528

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**Fig. 69.24** (**a**, **b**) (**a**) Rigid fxation with four plates provides vertical and horizontal stability to the maxilla. The nasal septum should be free of deviation, and the occlusion should be reproducible once interdental fxation is released. Bone plates are used to stabilize the osteotomy bilaterally at the nasomaxillary and zygomaticomaxillary buttress

areas. (**b**) Autogenous bone grafts have been adapted and fxated in the osseous gaps to optimize bone healing and minimize postsurgical relapse. Grafting may be indicated in complex movements, especially large advancements and down grafting cases (yellow arrow)

osteotomy gaps, and press-ft into position, or rigidly fxed if necessary [61]. Once the fxation has been competed, fnal measurements with calipers are made to confrm proper vertical placement (Fig. 69.24a, b).

#### **69.4.10 Checks to Be Made Before Plate Fixation of the Maxilla**


Once the maxillary fxation is completed, the intermaxillary fxation is released. The mandible is hinged with the condyles fully seated using the "triangular" fnger formation. Retractors should be used to hold the cheeks away from the posterior teeth, and the mandible is rotated upward such that the teeth ft into the maxillary splint. The tongue is also manipulated out of the way if it is interfering with closure. There should be a smooth closure into the splint without any shifting or deviation of the occlusion. Contact should occur simultaneously in the anterior and posterior areas.

#### **69.4.11 Closure**

Proper closure occurs in three steps.

#### **69.4.11.1 Nasal Cinch Suture (Alar-Base Suture)** [62]

With the dissection and exposure of the paranasal musculature during Le Fort I osteotomy, the nasal cinch suture provides appropriate repositioning of the soft tissue to minimize postoperative nasal base widening. A slowly resorbing suture (e.g., 2-0 polyglycolic acid) is placed from an intraoral approach into the alar base bilaterally, pulling the alar bases toward each other when tightened (Fig. 69.25a, b). If properly done, tightening should result in an equal or shorter alar base width when compared to the preoperative width. This will frequently result in an immediate upturned appearance of the nose, a protruded positioning of the upper lip, and edema. These immediate changes are transient and will disappear within a few weeks. Following healing, the procedure results in minimal widening of alar base from the preoperative measurement (Fig. 69.26a, b).

#### **69.4.11.2 V-Y Closure** [63]

Typical movements of the maxilla and normal healing of the circumvestibular incision can result in lip shortening,

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**Fig. 69.25** (**a**, **b**) An alar base cinch suture controls the alar base width and counteracts postsurgical widening of the alar base. Care is taken to correctly place the suture in the fbro adipose tissue and transverse nasalis muscle at the lateral nasal base, allowing medial positioning of the alar base during suture tying (yellow arrow)

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**Fig. 69.27** Vestibular soft tissue closure is performed with a running resorbable suture. A midline V-Y closure provides support to the upper lip and rolls the vermillion upward and outward, gives fullness to the lip, and makes a prominent white-roll. Closure is started posteriorly and moved anterior to bring the labial side mucosa forward, which is then, closed in the midline in the form of an inverted "Y" (yellow arrow)

**Fig. 69.26** (**a**, **b**) Measuring the alar base pre-surgically (**a**) and post-surgically (after edema subsides and soft-tissue settles) (**b**) and confrming that the size remains same

lip thinning, and decreased vermillion show. The Le fort I incision transects various components of the midface musculature, including the transverse part of the nasalis muscle, the myrtiformis muscle), and the levator anguli oris muscle.

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It is important to correctly suture the deep muscular layers in proper anatomic orientation, so that the facial contour may be maintained [64].

The V-Y closure is performed to combat these undesirable changes. With the use of a skin hook, the tissue of the midline vestibular incision is grasped and pulled superiorly. Using a resorbable suture (e.g., 4-0 vicryl), the incision is closed vertically by grasping the tissue 1 cm away from the midline on either side of the skin hook and advancing these edges together by tightening the suture. This provides for a 1 cm V-Y closure. The remaining closure is completed with either a continuous suture or interrupted sutures. The closure generally requires four or fve throws of the suture (Fig. 69.27, Fig. 69.9b).

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**Fig. 69.28** (**a**, **b**) A case of vertical maxillary excess treated with superior positioning of the maxilla showing frontal, right lateral and left lateral views. (**a1, a2, a3**) Pre-surgical photos of the patient; (**b1, b2,** 

#### **69.4.11.3 Vestibular Closure**

The remaining vestibular closure continues from the posterior portion of the incision. A running resorbable suture (e.g., 4-0 vicryl) is passed in a simple running fashion. Figures 69.10, 69.11, 69.28a, b, 69.29a, b, 69.30a, b and 69.32a, b depict the results achieved by the technique described above for different clinical indications. Figure 69.31 demonstrates steps involved in peforming a Lefort I osteotomy in a bimaxillary setting.

**b3**) post-surgical photos of patient (Also see Figs. 69.29 and 69.39 for the full case series images)

#### **69.5 Quadrilateral (Quadrangular) Osteotomy**

This high-level osteotomy is a variant of the Le fort I osteotomy and extends up to the lower part of the zygoma, to a point just below the infraorbital nerve bilaterally.

The indications for this osteotomy are midface retrusion, including excessive scleral exposure.

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**Fig. 69.29** (**a**, **b**) (**a1, a2, a3**) Pre-surgical occlusion of the same patient as in Fig. 69.28, treated with LeFort I superior repostioning. (**b1, b2, b3**) Post-surgical occlusion of the same patient

The benefts of the quadrangular osteotomy are that it improves the appearance of midfacial retrusion and fattening and improves zygomatic prominence and support for the lower eyelid. This osteotomy has minimal surgical morbidity and has acceptable outcomes. This may therefore be considered, especially in Asian patients, as a viable treatment alternative for midfacial advancement without augmentation of the malar region [65].

If the cuts are made from high to low a signifcant inferior movement of the maxilla can be achieved thus reducing the necessity for an interpositional bone graft (which would be required following a maxillary set down) and alloplastic onlay grafts for the zygomatic regions. It is more stable than conventional inferior positioning of the maxilla as there is good bone contact with native bone and no bone graft. This osteotomy also produces less rotation of the nasal tip than the conventional Le Fort I osteotomy. However, it is important to recognize that if there is a mild facial asymmetry in the maxillary region, this asymmetry can be emphasized with this high-level cut as the maxilla is advanced. The surgical technique is the same as for the conventional Le Fort I osteotomy, but signifcant sharp dissection of the masseter muscle from

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**Fig. 69.30** (**a**, **b**) Patient with maxillary occlusion cant and asymmetry (also see Figs. 69.31, 69.32 and 69.40)

the zygoma is required to expose the prominence of the zygomatic bone. The bony cuts are demonstrated in Fig. 69.33. The cuts are made just below the infraorbhital nerves.

The bone over the zygomatic prominence is thick, and control over the shape of the cuts is easier using a burr and a saw. This ensures that the bony cut does not propagate upward to the cranial base but instead is directed downward to the normal pterygomaxillary disjunction level. The other steps to complete the bony cuts and down-fracture the Le Fort I cut are made as above. Fixation is with miniplates. However, care must be taken to ensure the plates are not palpable in the infraorbital regions.

#### **69.6 Surgically Assisted Rapid Palatal Expansion (SARPE)**

SARPE is a combination of orthodontic and surgical techniques to expand the maxillary arch. This is ideal in patients with of transverse maxillary defciency, where the palatal suture has completely fused. This concept initially was met with skepticism but later was repopularized through the works of several clinicians, including Issacson and Ingram [66] and Haas [67], as a viable method of treating maxillary transverse defciency. SARPE is indicated in cases where skeletal maturity has been achieved, transverse maxillary defciency is present, excessive display of buccal corridors when smiling, and presence of anterior dental crowding. It has been shown that the midpalatal suture undergoes ossifcation at a wide range of ages [68]. In general, SARPE is recommended for patients who are over 16 years of age [69]. Nonsurgical expansions can be a reasonable consideration for patients younger than 12 years of age.

Before starting the surgery, it is important to confrm the secure placement of the appliance and also the presence of the device key to activate the appliance.

This procedure follows Le Fort I single piece osteotomy. The maxilla is *not* down-fractured. Relieving of the osteotomies present at the zygomaticomaxillary buttresses is done, as this allows clearance during separation. The midline

**Fig. 69.31** (**a**–**m**) Surgical procedure for correcting the maxillary occlusion cant (also see Figs. 69.30, 69.32 and 69.40). (**a**–**c**) Sagittal split osteotomy cuts. (**d**) Incision marking for le fort Osteotomy. (**e**, **f**) Osteotomy cuts marked and made for asymmetric superior repositioning of maxilla. (**g**) Down-fracture of maxilla. (**h**) Superior repositioning

of maxilla. (**i**) Fixation of maxilla with mini plates and screws. (**j**) Open bite on right side of occlusion because of asymmetric superior repositioning. (**k**) Unilateral sagittal split osteotomy of mandible split and fxed with mini plates and screws. (**l**) New Occlusion achieved. (**m**) Closure of wound done

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**Fig. 69.31** (continued)

gingiva is elevated to expose the alveolus. The midline osteotomy is carried out using a sagittal or piezo saw from the piriform rim of the nose, to the alveolus. The mid-palatal suture osteotomy is completed with chisels. The zygomaticomaxillary buttresses clearance is confrmed intraoperatively by activating the palatal appliance (Fig. 69.34a–c). The remainder of the procedure is according to Le Fort 1 single piece osteotomy [70].

#### **Salient Features of SARPE**


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**Fig. 69.32** (**a**, **b**) (**a1, a2, a3**) Pre-surgical pictures of patient with cant; (**b1, b2, b3**) postoperative asymmetric superior repositioning of maxilla and unilateral sagittal split osteotomy of the mandible to close the open bite created (Also see Figs. 69.30, 69.31 and 69.40)

7 mm, a SARPE procedure is preferred as it would offer more stability.


#### 1536

**Fig. 69.33** It is important to continue the saw or cut with a fssure bur through the inferior part of the zygomatic arch and extend it inferiorly and posteriorly to enable the important back cut to the pterygoid plates. This reduces the possibility of unwanted propagation of fractures to the cranial base

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**Fig. 69.34** (**a**) Maxilla down-fracture, paramedial osteotomy, palatal expansion device in situ, and checking for the horizontal segmental movement. (**b**) Midline palatal osteotomy, device for palatal expansion, (**c**) Tooth- borne Haas & Hyrax Appliance

**Fig. 69.34** (continued)


#### **69.7 Sequence of Bimaxillary Surgery**  (Fig. 69.31a–m)

A single surgical procedure can be employed to correct skeletal deformities of the mandible and the maxilla as well. The surgeon generally determines the preferred sequence. The authors personal preference is provided below.

1. The mandibular bony cuts are usually performed frst, without splitting the mandible. This is followed by completion of the maxillary osteotomy, repositioning and fxation. In the past, fxation was only by trans-osseous wiring. Hence, when the mandible was performed frst, its position was arbitrary as it incorporated the mobile proximal fragment (due to the TMJ) based on which the fnal maxillary position was determined. To avoid this the maxilla was completed frst.


The authors personal preference has been detailed above. Alternatively, mandibular splitting may be performed frst, and an intermediate splint may be used to to fx the mandible to the unoperated maxilla. The maxilla may then be stabilized to the operated and repositioned mandible. However, it must be noted that stabilization and fxation of the mandible are more challenging than for the maxilla. Rigid fxation may be more challenging if an improper or misdirected split occurs. The procedure may even need to be aborted altogether. However, by stabilizing the maxilla frst, the mandible can use appropriately positioned maxilla for stabilization. Therefore, we have always preferred to complete the maxillary surgery before mandibular surgery.

Having listed a general guide above, we reiterate that no dogma should be given regarding the sequence of maxillary or mandibular surgery. Proper planning and preparation will in turn logically dictate the sequence, which must be kept fexible [73].

#### **69.8 Soft Tissue Changes with Le Fort I Osteotomy**

Changes in the jaw position in turn lead to changes in the position of soft tissues such as the lips, cheeks, and nose [74]. The lips may show thinning, reduced vermillion show, and may lack adequate lip support [46]. The nasal tip may be upturned, the alar base width may increase, and the nasolabial angle may widen [75] (Fig. 69.35a–c). Soft tissue swelling

A. Dabir and J. Vahanwala

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 69.35** (**a**–**c**) (**a**) reduction of a strip along the caudal septum will shorten the nose; (**b**) reduction involving the nasal tip as shown will increase the nasolabial angle; (**c**) wedge reduction predominantly at the septal base will reduce the nasolabial angle

may take up to a year to resolve, so these changes may not be apparent immediately [76]. In some regions, such as the subnasale, and the lips, greater than 10% change has been documented over 5 years [4]. Nasal changes are quite complex and are therefore unpredictable. Both the structure of the nose (including nasal cartilage connective tissue, anterior nasal spine, and the other nasal cartilages) and the degree of movement of the maxilla play a role in nasal changes. Other patient-related factors, including thickness and morphology of the soft tissue, postoperative healing, age, and ethnicity, can also affect nasal changes, which may either be favorable or unfavorable or benefcial. The nasal width alone increases predictably in Le Fort I osteotomies, and the increase in width depends on the extent of maxillary movement. Adjunctive procedures to limit widening of the nasal width may be performed intraoperatively. These include alar cinch suture and piriform aperture sculpting. Alternatively, the changes may be accepted and later procedures can be performed if necessary. The disadvantage of this is the need for an additional surgical procedure, e.g., alar wedge resection rhinoplasty. The alar cinch suture and V-Y closure (ACVY) is effcient and less invasive in controlling nasolabial changes. Its long-term results need to be evaluated. One study showed that the alar base cinch suture reduced the inter-alar width to its preoperative width following a Le Fort I osteotomy. The suture was stable when evaluated at 12 months and 3 years postoperatively [77]. There have been studies comparing nasal and maxillary vermilion morphology after Lefort osteotomies by simple primary closure, Single VY closure and Double VY closure. The results indicated that better aesthetics are seen in double VY closure cases (See Hackney et al. 1989, Ledezma et al. 2014, in Additional reading provided). However a systematic review in 2014 couldn't reach a conclusion regarding the effcacy of various methods of closure in Lefort Osteotomies.

#### **69.9 Specifc Considerations**


metrical jaw movements (deviations), malocclusion, and aberrant maxillary position.


#### **69.9.1 Adjustment to the Anterior Nasal Spine and Piriform Aperture**

Mommaerts et al. reported that the anterior nasal spine is a signifcant component of nasal tip projection and may be reduced to limit the degree of nasal tip rotation [81]. Betts et al. also stated that changes in the lateral part of the piriform aperture signifcantly affected the soft tissue of the nasal base and nasal tip projection [82].

It is important not to remove too much of the septum as this can produce a retracted columella, which is a potentially unattractive feature.

Osseous recontouring of the nasal crest of the maxilla and/or resection of a portion of the caudal extent of the cartilaginous septum is recommended to keep interference at bay. Placement of a suture through the anterior nasal spine and cartilaginous septum to prevent its displacement upon removal of the nasoendotracheal tube is benefcial.

#### **69.9.2 Efect of Changing the Inclination (Slope) of the Osteotomy Cut**

If the osteotomy cut is made in a parallel direction to the occlusal plane and the maxilla is advanced, the maxillary incisor exposure will increase but the face height will not change. However, if the osteotomy cut starts high posteriorly and slopes downwards toward the piriform aperture, the maxilla will move down the slope as it is advanced, thus increasing the maxillary incisor exposure. The mandible will subsequently rotate in a clockwise direction and the lower anterior face height will increase (Fig. 69.36a, b). The opposite is true for the osteotomy cuts that start low posteriorly and slopes upward toward the piriform aperture (Fig. 69.37a, b).

#### **69.9.3 Impacted Wisdom Teeth**

If an impacted maxillary wisdom tooth is indicated for removal, this is done through the sinus foor. Using a rotary drill with a rosette bur, the bone from the sinus foor, which lies above the impacted tooth, is removed. Next, a tapered fssure bur is used, and the bone just adjacent to the impacted tooth is removed. The impacted wisdom teeth may also be sectioned if necessary

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**Fig. 69.36** (**a**, **b**) Diagram showing effects of the inclination (high to low postero-anteriorly) of the osteotomy cut when advancing the maxilla—(**a**) osteotomy inclination to increase incisor exposure and potentially increase lower face height, (**b**) advancement of maxilla producing increase of lower facial height due to downward ramp effect

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 69.37** (**a**, **b**) Diagram showing effects of the inclination (low to high postero-anteriorly) of the osteotomy cut when advancing the maxilla—(**a**) osteotomy inclination to reduce incisor exposure and poten-

to aid in removal; this usually depends on the developmental stage. The tooth is delivered using a dental elevator. Rarely, perforation through the palatal mucosa may occur.

#### **69.9.4 Erupted Wisdom Teeth**

If the maxillary wisdom tooth is completely erupted, this may be extracted prior to down-fracture. This will allow the operator to have a stable "workbench" during extraction. In order to maintain the blood supply to the down-fractured maxilla, the adjacent palatal and labial mucosa must be preserved carefully at the time of extraction.

#### **69.9.5 Considerations of Pre-operative Difculties**

The pre-surgical workup and planning of patients who require corrective jaw surgery required detailed analysis of clinical features, study models, and plane radiographs. Radiographic analysis includes comprehensive assessment of lateral cephalograms, postero-anterior cephalograms, and orthopantomograms. The need for multiple individual planar views has been replaced by the advent of cone beam technology.

#### **69.9.6 Considerations of Operative Difculties**

Horizontal osteotomy of the maxilla should result in a clean pterygomaxillary separation to subsequently allow for tially reduce lower face height, (**b**) advancement of maxilla producing reduction of lower facial height due to upward ramp effect

down-fracture and mobilization. At this step, the pterygoid plates should ideally remain intact and attached to the skull base. However, in some exceptional cases, such as patients with cleft maxilla, the pterygoid plates are unusually thick and well buttressed. On the other hand, some patients have thin and almost translucent pterygoid plates [83]. Pterygomaxillary synostosis (fusion) may be seen in up to 12% of all patients [21].

If the pterygoid plates fracture at a lower level, this may cause diffculties in down-fracture and mobilization, because of the attachment of the pterygoid musculature. On the other hand, if the plates fracture at a higher level, the fracture may propagate into and along the skull base, which can potentially cause neuro-ophthalmic complications.

On postoperative CT scans, the incidence of pterygoid plate fracture after a Le Fort I osteotomy was found to range from 58 to 75% [84, 85]. However, despite this high incidence, the incidence of fractures propagating to the skull base/orbit is low [83].

Lanigan et al. carried out a study on unfxed fresh cadavers and found that 26% of cases were "diffcult downfracture." They stated that this was probably due to the presence of "thick bony maxillary walls" [83].

These authors stated that if a diffcult down-fracture was encountered after a routine Le Fort I osteotomy, then the posterior walls of the maxilla must be sectioned completely using an osteotome. Alternatively, sectioning through the tuberosity could be performed, using a micro-oscillating saw or straight osteotome, as this would avoid the thick posterior walls and aid in pterygomaxillary separation. However, these authors have stated that it would not be possible to totally prevent untoward fractures that could occur during pterygomaxillary disjunction and down-fracture. We emphasize that thorough CBCT imaging should be undertaken preoperatively, as this would familiarize the surgeon with the maxillary morphology.

The following maneuvers may help if the surgeon fnds diffculty in down-fracture following osteotomy and disjunction:


O'Regan and Bharadwaj stated that an osteotome or saw must never be used blindly in these situations [86].

#### **69.9.7 Proper Positioning**


**Fig. 69.38** (**a**–**c**) (**a**) The proper method for condylar seating at the time of maxillary positioning prior to fxation. Posterior prematurities are best appreciated with this method. (**b**) Pressure on the chin to push the anterior aspect of the maxillary osteotomy together may rotate the condyles inferiorly and posteriorly while maxillary fxation is applied. (**c**) Upon release of intermaxillary fxation, the condyles may return to the fosse, and an open bite may appear. Unfortunately, this open bite may not appear immediately, especially if postoperative elastics are used to "guide" the occlusion

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surgical move. This is much less likely with advancement than it is with other moves such as impaction.

• It is often easiest to adapt the plates for fxation with Le Fort osteotomy and initially secure them only to the inferior fragment. Once all the plates are properly bent and secured to the inferior fragment, the maxillomandibular complex and condyles can be positioned with great care, and the shape and bending of the plates critically evaluated and secured to the superior fragment in succession, while the maxillomandibular complex is held in position.

#### **69.9.8 Nutritional Support**

Orthognathic surgery throws up many physiological challenges. These include postoperative facial swelling and catabolism which increase the nitrogen requirements. If these are not met, wound healing may be compromised. A diet fortifed with macro- and micronutrients and adequate hydration is therefore essential [87].

Mandibular movements may be restricted in the postoperative period, owing to facial swelling and pain. Meeting the daily nutritional needs and hydration requirements (Table 69.1) may therefore be diffcult. Studies have shown that in 6 weeks following surgery, patients can lose between 3.1 and 6.8 kg of weight [88].

It is important to adapt the diet to suit these needs, to promote wound healing, and to minimize postoperative complications. Another important factor in patient recovery is the patient's mood. Adequate nutrition and hydration will serve to improve the patient's mood, thereby diminishing postoperative irritability or depression [89]. Dietician assessment of nutritional status is essential to ensure that the above goals are achieved.

The modifcation of the diet is a sequential process. This aims at reducing the masticatory forces on the underlying healing bone, which in turn optimizes the conditions for healing.


**Table 69.1** Recommended postoperative nutrition requirements for patients above 16 years, undergoing orthognathic surgery [87]


chewing, and foods may be mashed. The high-energyhigh-protein diet must be continued.

3. After the second week, light chewing may be done, and a soft diet is recommended. The jaw muscles may fatigue easily at frst, but gradually the muscles adapt to the new position. The soft diet is continued for two months, after which regular diet may be resumed [87, 90–98].

#### **69.9.9 Complications**


Rigid fxation with plates provides the initial stability until bone has united. Bone frst unites in the pterygoid region [99]. The most stable maxillary movement is superior repositioning, followed by advancement, and the least stable is inferior repositioning. However, the studies looking at the inferior positioning of the maxilla have been based on the need for bone grafting. Studies have reported relapse rates for maxillary superior repositioning of the maxilla ranges from a mean of 0–18% for the anterior maxilla and 6–7% for the posterior maxilla. Relapse rates for maxillary advancement range from 5 to 15%. As with most orthognathic surgery, relapse is greater with increase in the maxillary advancement. With inferior maxillary repositioning (using bone grafts), there may be 28% anterior relapse and up to 70% posterior relapse [100]. Nonunion is rare and probably associated with failure of the initial plate fxation and poor bony contact. If this persists for greater than 6 months, further surgery with rigid fxation and autogenous bone grafting is recommended [101]. Maxillary advancement and posterior and superior movements are shown to be stable, whereas inferior and transverse movements are unstable [99–110]. The use of autogenous bone grafts and/or hydroxyapatite has been proposed to improve the stability of inferior repositioning of the maxilla [101, 111–117].


### **69.10 Recent Advances** (Refer Figs. 66.21 and 78.51)


#### **69.11 Conclusion**

The development of modern maxillary orthognathic surgical procedures had diverse historical origins and contributions. With advancement in technique and the introduction of safe hypotensive anesthesia, the Le Fort I osteotomy has been increasingly utilized over the last four decades. Over the years, various modifcations of the osteotomies, ORIF methods and bone grafting to the mobilized maxilla, have continued to evolve and progress. The Le Fort I osteotomy of the maxilla is one of the core procedures in orthognathic surgery for the management of facial skeletal deformities. The surgery, often used in conjunction with the bilateral sagittal split osteotomy, is used to correct functional and cosmetic irregularities in all three planes of space and can be utilized in the treatment of a wide range of malocclusions. Traditionally, the surgery has been known for its low technical diffculty and dependable results. Changes in the soft tissue of the nose, lips, and cheeks due to this surgical procedure need due consideration.

The risk of complications is higher in patients with segmental Le Fort 1 osteotomies or anterior movements greater than 9 mm. Efforts to minimize maxillary movement (e.g., with two-jaw surgery) are recommended to reduce complications. An emphasis should be placed on proper pre-surgical orthodontics and solid pre-surgical planning to ensure predictable and stable results. It is also imperative to plan and provide for optimal nutrition as Orthognathic surgery throws up many physiological challenges that may compromise the nutritional status including catabolism, postoperative facial swelling, and increased nitrogen requirements to promote wound healing. The premise of maxillary orthognathic surgery is therefore a multidimensional approach through planning, execution, and postoperative management.

Disclosure Authors have no fnancial conficts to disclose. Authors have written consent and reconfrmation from the patients for the use of clinical pictures.

#### **69.12 Case Scenarios**

**Case Scenario 1** (Figs. 69.28, 69.29 and 69.39a–h)

#### **(A) Chief Complaints**

Gummy smile Long face Defcient chin Protruding upper front teeth

#### **(B) Postoperative Result**

Competent lips Normal chin projection Balanced face

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**Fig. 69.39** (**a**–**h**) Vertical maxillary excess with mandibular defciency. Treatment: Le fort I with superior repositioning of maxilla; bilateral sagittal split ramus osteotomy advancement; advancement genioplasty. (**a**) Pre-operative profle picture; (**b**) pre-operative frontal view; (**c**) pre-operative lateral cephalogram. (**d**) Pre-operative OPG; (**e**) postoperative lateral profle; (**f**) postoperative frontal view; (**g**) postoperative lateral cephalogram; (**h**) postoperative OPG showing the implants and the osteotomy cuts in mandible. (Also see Fig. 69.28)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 69.40** (**a**–**i**) Facial asymmetry with maxillary occlusal cant, deviation of chin (surgery for left TMJ ankylosis and genioplasty done previously elsewhere). Treatment: Le fort I osteotomy for correction of maxillary occlusal cant; right unilateral sagittal split ramus osteotomy to close the open bite. (**a**) Pre-operative profle picture; (**b**) pre-opera-

tive frontal view; (**c**) pre-operative PA skull; (**d**) pre-operative OPG; (**e**) pre-operative lateral cephalogram; (**f**) postoperative profle picture; (**g**) postoperative frontal view; (**h**) postoperative PA skull; (**i**) Post-operative OPG (Also see Figs. 69.30, 69.31 and 69.32)

#### **Surgical Procedure**

Le fort I osteotomy for superior repositioning of maxilla

Bilateral Sagittal Split Ramus osteotomy for advancement of mandible

Advancement genioplasty Later rhinoplasty was done.

#### **Case Scenario 2** (Figs. 69.30, 69.31, 69.32, and 69.40a–i)

#### **Chief Complaints**

Facial asymmetry

Deviation of chin to left

Incisal/occlusion cant (Fig. 69.30)

Facial asymmetry was secondary to ankylosis of left TMJ. Left side treated with costochondral graft when patient was younger.

#### **Pre-operative Findings**

Occlusal cant

Asymmetry of face

The patient presented with occlusal canting visible at the anterior region. This needed to be addressed as it is clinically evident and may affect visual cosmesis.

Judge the incisal cant by drawing an imaginary interpupillary line and its inclination with incisal cant represented by the metal scale held in incisors

#### **Surgical Plan** (Figs. 69.31 and 69.32)

Le Fort I osteotomy for superior repositioning of maxilla on right side by 5 mm

Sagittal split osteotomy on right side of mandible to match mandible to maxilla

#### **References**


and Maxillofacial Surgeons. 2020 Sep. https://doi.org/10.1016/j. joms.2020.09.005.

122. Heufelder M, Wilde F, Pietzka S, et al. Clinical accuracy of waferless maxillary positioning using customized surgical guides and patient specifc osteosynthesis in bimaxillary orthognathic surgery. Journal of Cranio-maxillo-facial Surgery: Offcial Publication of the European Association for Craniomaxillo-facial Surgery. 2017;45(9):1578–85.

#### **Additional Readings**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

**70**

## **Facial Asymmetry**

Neelam N. Andrade, Paul Mathai, and Neha Aggarwal

#### **70.1 Introduction**

Physical appearance is of much signifcance to the humans, as the human mind perceives the slightest form of deviation from normal form, function, and symmetry of the body and especially of the face as it is easily discernible [1]. Facial asymmetry could be defned as a clinically perceptible and signifcant difference between the two halves of the face. Every individual has some degree of asymmetry which may provide a uniqueness to the face. However, the magnitude and acceptability of the same depend on the location of the asymmetry and the patient's perception of disproportion. Facial asymmetry may also adversely affect the patient's nutritional and psychosocial development [2].

Any abnormality of the soft or hard tissues can lead to asymmetry. This could be a consequence of a congenital anomaly, a developmental, or an acquired defect. Asymmetry can be progressive in nature, while those acquired due to trauma or ablative surgeries are non-progressive [2, 3]. It is prudent for the clinician to consider the aetiology of the asymmetry, the extent, and its severity in all three dimensions in order to provide an optimal treatment plan. Besides, it is important to take into consideration factors such as growth, timing of treatment, and psychological aspirations of the patients when deciding the treatment plan [3, 4].

The present chapter will discuss the etiopathogenesis and classifcations, clinical considerations, and diagnosis, evaluation, and treatment planning of facial asymmetries. Few interesting case scenarios will also be discussed for a better understanding of clinical presentations and their management.

#### **70.2 Classifcation**

Understanding the etiopathogenesis and classifcation of facial asymmetry allows for accurate diagnosis, optimal treatment planning, and improved surgical outcomes. Facial asymmetries are most commonly classifed according to aetiology or morphology. Other classifcations are based on time of onset, structures involved, and surgical planning outcomes and may even be restricted to the mandible alone. Table 70.1 is a summary of the various classifcation systems available to us today [5–19].

We have identifed three classifcations that are essential for the evaluation and treatment planning of facial asymmetries [Table 70.2 by Cheong et al. (2011) [13], Table 70.3 by Wolford et al. in (2009) [11], Table 70.4 by Wolford et al. (2014) [2, 19–21]].

#### **70.3 Diagnostic Evaluation**

Facial asymmetry is usually the least at the cranial base level and increases toward the lower levels of the face, with the mandible and chin commonly exhibiting the greatest asymmetry. Hence, the cranial base is used as a reference plane for assessing the type and severity of the asymmetry in the middle and lower thirds of the face. Conditions where the cranial base is also involved like syndromic or non-syndromic craniosynostosis, tumors of the cranium, and midface and Tessier's craniofacial clefts cannot be assessed in a routine manner. The presence of orbital dystopia, unequal pupillary heights, and/or unequal ear heights will make the assessment more challenging [2, 20, 22, 23].

Every clinical examination begins with identifying the chief complaint of the patient followed by a detailed physical and medical evaluation of the patient. In order to better understand the facial asymmetry, it is studied in the sagittal, coronal, and vertical dimensions with the cranial base as the reference plane. Common facial planes that represent the

N. N. Andrade (\*) · P. Mathai · N. Aggarwal

Department of OMFS, Nair Hospital Dental College, Mumbai Central, Mumbai, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1549

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_70

**Table 70.1** Summary of the various classifcation systems


**Table 70.2** Major etiological factors of facial asymmetry, according to Cheong et al. (2011) [13]


cranial base are the pupillary plane, the ear plane, and the clinical Frankfort horizontal plane. It is also important to note that patients may hold the head in an abnormal position or use hairstyles and mannerisms to mask the extent of the asymmetry [e.g., a patient with a defcient mandible may tip his head upward in order to improve chin projection]. It is important to identify these compensatory mechanisms during the treatment planning process. Similarly, it can be benefcial to study the lower or middle third individually in comparison with the unaffected upper third [cranial base] by blocking out the part not being studied with an opaque sheet [e.g., card board] [20, 23].

#### **70.3.1 Clinical Evaluation: Frontal, Axial, and Profle**

#### **Frontal View**

The patient's head is positioned such that the interpupillary plane or ear plane [passing through the bottom of the ear lobes or tragi of the ears] is parallel to the foor. The pupillary plane can also be used for assessing bilateral vertical discrepancies by measuring height differences from the plane to the mandibular angles, chin, nose, and commissures (Fig. 70.1). The facial midline is represented by a vertical plane passing through the nasion or glabella, perpendicular to the pupillary plane and ear plane (Fig. 70.2). It allows to compare the degree of left-to-right asymmetry and transverse facial width discrepancies of various facial structures [e.g., orbits, pupils, malar eminences, nose, commissures, and mandibular angles]. In case of some imbalance in the frontonasal region [e.g., past naso-orbito-ethmoidal trauma], other landmarks can also be used as a reference to identify the facial midline, e.g., half the interpupillary or inter-canthal distance, the subnasal point, or the philtrum [20, 22].



**Table 70.4** Wolford's classifcation of condylar hyperplasia [CH] 2014 [2, 19–21]


The patient should be reminded to relax the peri-oral musculature for assessing the tooth to upper lip relation at rest [e.g., patients with vertical maxillary excess will constantly purse their lips to reduce excessive gum and teeth show]. The smile needs to be assessed for the amount of gingival show on either side, tooth to upper lip relation, comparison of dental midline with facial midline and symmetry by comparing parallelism of commissural and pupillary lines. Finally, a tongue blade or thin ruler can be placed between the maxillary and mandibular canines and premolars to assess the presence of a cant in relation to the pupillary plane (Fig. 70.2). Comparing the vertical heights from the pupillary plane to the canine tips on either side can help quantify the cant. An occlusal plane inclination of greater than 4° is said to cause signifcant perceptible asymmetry.

Assessment of midline structures such as nasal bridge, nasal tip, philtrum, and the chin point should also be carried out. Submental [worm's-eye] (Fig. 70.3) and superior [bird'seye] views (Fig. 70.4) are very useful in assessing deviation of the abovementioned structures. We can also assess symmetry

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**Fig. 70.1** Various facial planes **A** horizontal plane (interpupillary plane) **B** horizontal plane (inter tragal plane) **C** horizontal plane (plane marked through ear lobes) **D** vertical plane (mid-sagittal plane) ©Association of Oral and Maxillofacial Surgeons of India

**Fig. 70.2** Occlusal cant in relation to the pupillary plane and asymmetry marked from medial canthi to the oral commissure

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 70.3** Submental (worm's-eye) view exhibiting asymmetry in the lower facial third and skeletal midline

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**Fig. 70.4** Superior (bird's-eye) view exhibiting midline discrepancy and rotation of the face

and projection of the anterior cranial vault, orbital areas, nose, cheeks, malar eminences, and mandibular body contours.

#### **Profle View**

In order to avoid underestimating the severity of the facial asymmetry due to compensatory head postures, it is essential to position the head so that the clinical Frankfort horizontal plane (a line from the tragus of the ear through the palpable bony infraorbital rim) is parallel to the foor (Fig. 70.5). The patient should also be reminded to relax the peri-oral musculature to better assess the tooth to upper lip relation at rest. Evaluating the left and right sides from the profle view will allow assessment of discrepancies in the antero-posterior and vertical dimensions [e.g., maxilla, mandible, and chin] rather than asymmetry evaluation.

#### **70.3.2 Oral Examination**

Orthodontic study models mounted in centric relation by face-bow transfer onto a semi-adjustable anatomic articulator help in dento-alveolar and occlusal assessment with a further advantage of studying the occlusion from the lingual aspect. The dental arches are evaluated for overdevelopment, underdevelopment, presence of yaw, and asymmetry in the antero-posterior, transverse, and vertical planes. The dental examination should include the presence or absence of missing, deformed, carious, impacted, or ankylosed teeth; dental midline shift; dental crowding or spacing; congenital deformity [e.g., cleft alveolus in a case of cleft lip and palate]; habitual pattern [e.g., tongue thrusting or thumb sucking]; pathology; and size of tongue and trauma (Figs. 70.6, 70.7, and 70.8). These fndings can be incorporated into the treatment planning.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 70.5** Orientation of FH plane parallel to the foor

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**Fig. 70.6** Complete telescoping of the maxilla

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**Fig. 70.7** Crowding in both arches along with a reverse overjet

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 70.8** Non co-incident dental midlines (blue-upper dental mid line, yellow-lower dental midline)

#### **70.3.3 Photographic Examination**

A dedicated photography room where extra-oral and intraoral photographs are taken under standardized settings [e.g., lighting, background, focal length, and distance-to-subject] is ideal. Extra-oral photographs of the frontal [with and without smile, occlusal and mandibular inferior border cant], three-quarter, submental, and superior views are essential for the assessment of facial asymmetry. Intra-oral frontal, lateral, superior [45° to the occlusal plane from above], and inferior [45° to the occlusal plane from below] views with the teeth in occlusion are essential for dento-alveolar assessment [11, 23–26].

#### **70.3.4 Radiographic Examination**

The three primary radiographic examinations performed in the assessment of facial asymmetry are lateral cephalometry, postero-anterior cephalometry, and orthopantomography. They have been described briefy below. As a rule, serial cephalometric assessment every 6 months for a minimum duration of 1 year may be helpful in determining if the asymmetry is static and stable or if it is progressive [24, 25].

1. Lateral Cephalometry:

It is used to assess hard tissue and soft tissue relationships in 2D, i.e., antero-posterior and vertical dimensions. This tool is less commonly used to assess facial asymmetry. The head is placed into a reproducible position within the cephalostat with the help of the nasal bridge indicator and ear roads which closely approximates the clinical Frankfort horizontal plane. The patient keep should also be instructed to keep the jaws in centric relation with the teeth lightly touching and the lips slightly parted or relaxed. The ability of the cephalostat to reproduce the near about the same position every time allows for comparative cephalometric analysis and super-imposition of tracings. Bilateral vertical discrepancies [e.g., increased vertical dimension of the body and ramus-condyle unit of the mandible in unilateral condylar hyperplasia type 2] can usually be assessed in a lateral cephalogram. The right and left sides are presented as two separate nonsuper-imposing lines, and this can be measured as a discrepancy between the two images of the occlusal plane and inferior borders of the mandible (Fig. 70.9).

2. Orthopantomograph [OPG]:

The OPG is an excellent tool to evaluate mandibular asymmetry and dental status. The anatomy of the condyle—ramus unit, body, and inferior border of the mandible is readily discernible. Increase or decrease in dimensions or changes in mandibular morphology can be studied. In cases of unilateral asymmetry, the affected side can be compared to the normal side. The course of the inferior alveolar nerve can also be assessed and is of vital importance if an inferior border osteotomy is being performed [e.g., inferior border osteotomy in cases of unilateral condylar hyperplasia type 2 where the inferior alveolar nerve might be coursing near the lower border of the mandible] (Fig. 70.10). The OPG is also an excellent tool for the screening of maxillofacial pathology that may cause facial asymmetry, e.g., tumors and fbro-osseous lesions.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 70.9** Lateral cephalogram showing double images of the inferior border of the mandible (blue arrows) along with displaced IAN canal (yellow arrow) in a case of type 2 condylar hyperplasia

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 70.10** OPG demonstrating the difference in height of the mandibular body (blue arrows), displacement of the IAN canal toward the inferior border (yellow arrows)

#### 3. Postero-antero Cephalometry:

The PA cephalogram allows a comparative study of the symmetry between the structures of the right and left sides. Projections can be obtained in both open mouth position and centric occlusion with head oriented in natural head position to identify the full extent of static and dynamic [functional] asymmetry. The horizontal reference plane is represented by a line passing through the bilateral zygomatico-frontal sutures. The vertical reference plane is a line perpendicular to the horizontal plane passing through crista galli. Transverse and vertical distances of various facial structures are measured by drawing perpendicular lines drawn from the structures in question to the vertical and horizontal reference planes. By comparing the distances measured bilaterally, the type and extent of the underlying asymmetry can be assessed. Additionally, a shift in the dental midlines can be assessed by comparing them to the skeletal midline. The Grummons and Ricketts analyses are commonly used PA cephalometric analyses for the evaluation of facial asymmetry (Fig. 70.11).

4. Computed Tomography/Cone Beam CT with 3D Reconstruction:

The main advantage of the 3D CT scan is that it helps in visualization and treatment planning of complex facial asymmetry in cases like craniosynostosis, Treacher Collins syndrome, hemifacial microsomia (Figs. 78.4, 78.5 and 78.6), TMJ ankylosis, and unilateral condylar hyperplasia (Fig. 70.12a, b). Unlike cephalometric and panoramic radiographs, there is no superimposition of structures, the absolute position of anatomical landmarks can be defned, and viewing is possible from any angle. It is also an excellent tool for patient education. The CT scan data can be used for fabrication of stereolithographic

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**Fig. 70.11** Grummons and Ricketts analysis using PA Cephalogram for evaluating the facial asymmetry. Horizontal reference plane (red); vertical reference plane (yellow); ramal height (blue); intercuspid width (green); intermolar width (purple). Refer to additional reading

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 70.12** (**a**, **b**) 3DCT face analysis for assessing the facial asymmetry. Various parameters include, Arbitrary horizontal reference plane assuming orbits are normal (black); FH plane (purple); mandibular height [canine to mandibular plane (orange)]; maxillary height (frst

molar to FH) (red); ramal length (Co superior to Go inferior) (green); occlusal plane (yellow); lateral ramal inclination (Co superior to Go posterior to FH) (brown); midsagittal plane (light blue)

medical models which help make surgical planning even easier. The disadvantage of the CT scan is the exposure to a high radiation dose; with the introduction of the CBCT, the amount of radiation exposure has been greatly reduced. 3D reconstruction, stereolithographic model printing and integration with 3D stereo photogrammetry data allows for treatment planning, treatment simulation, and assessment customized according to the patient [e.g., Dolphin 3D, IPS by KLS Martin]. Lastly, both CT and CBCT provide valuable information regarding the hard tissue status of the TMJ and aid in the diagnosis of reactive [infammatory] arthritis of the TMJ, osteoarthritis of the TMJ, idiopathic condylar resorption, avascular necrosis, and degenerative remodeling of hard tissues of the TMJ in dentofacial asymmetries [24, 25].

5. Magnetic Resonance Imaging:

MRI is primarily used to study the soft tissues of the TMJ [e.g., disc, capsule, ligaments] and combined with the CT/CBCT scan data is able to accurately diagnose reactive [infammatory arthritis] of the TMJ, internal derangements, condylar resorption, and degenerative remodeling of soft tissue of the TMJ in dentofacial asymmetries (Fig. 70.13a, b) [e.g., thinning and displacement of the disc of the contralateral unaffected TMJ in cases of unilateral condylar hyperplasia] [24, 25].

#### **70.3.5 Stereophotogrammetry**

It is the construction of a three-dimensional model based on the positions of recognizable points or landmarks in several different photographs. It utilizes two or more cameras confgured to capture a pair of stereo images of the surface of patient's face which are then used to generate a 3D image of the face by triangulation performed through sophisticated stereo algorithms. The technique is minimally invasive and has an expanded coverage of close to 360° of the structure being studied with quick capture speeds (often under 1 second). These advantages make it is particularly useful when working with young children [with craniofacial deformities] for whom quantifcation of facial features can be challenging [25, 26]. The ability to store images for subsequent use, accurate reproduction of the surface geometry of the face, and ability to map realistic color and texture data onto the recorded geometric shape make this technique the preferred facial surface imaging modality over older conventional imaging modalities like laser scanning [26].

#### **70.3.6 Stereolithographic [SLA] Models**

Medical modelling involves frst acquiring a CT, CBCT, or MRI. This data consists of a series of cross-sectional images of the region being studied. The selected part is now created in a layer-by-layer fashion using photopolymerization ultimately forming a three-dimensional solid. The use of such models in maxillofacial surgery has signifcantly improved predictability of clinical outcomes in facial asymmetry cases when compared to similar treatments without its use. The models facilitate direct visualization of complex 3D facial asymmetry, decrease operating time due to better treatment planning, and can also be used as an educational tool for patients (Fig. 70.14) [27].

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**Fig. 70.13** (**a**, **b**) MRI of TMJ showing anteromedial disc displacement (yellow arrows)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 70.14** Facial asymmetry demonstrated on STL model involving both the midface and mandible with hyperplasia involving the right side

#### **70.3.7 Virtual Surgical Planning [VSP]/ Computer-Aided Surgical Simulation [CASS]**

VSP/CASS involves four key stages demonstrated in Box 70.1.

Figure 70.15 shows the sequence involved in VSP/ CASS. The advantages are an increased dental relationship accuracy, reduced OR time, increased patient satisfaction, and decreased costs. Simulating surgery preoperatively allows measurements to the 1/100th of a millimeter, and when combined with 3D-printed splints and customized prebent plates, the reconstructive and aesthetic outcome is supe-

#### **Box 70.1 Four key stages in virtual surgical planning**


**Fig. 70.15** Flow chart outlining the steps involved in virtual surgical planning has been reproduced after permission from the article "Farrell BB, Franco PB, Tucker MR. Virtual surgical planning in orthognathic surgery. Oral Maxillofac Surg Clin North Am. 2014; 26(4):459–73" [28]

rior to traditional 2-dimensional (2D) modelling and cephalometric tracing [28].

#### **70.3.8 TMJ Examination**

TMJs must be healthy for predictable orthognathic surgery outcomes. The TMJ must be assessed before and after orthognathic surgery for joint noises (clicking and popping), localized tenderness, radiating facial [e.g., headaches] and neck pain, and limitation of mouth opening and jaw locking. The literature reports a higher incidence of TMD in patients with retrognathic mandibles and in those with steep occlusal planes [29, 30].

There is no conclusive evidence regarding the effect of orthognathic surgery on TMD with opinions split between improvement, no change, or worsening of signs and symptoms. However, high-angle, class II patients with pre-existing TMD undergoing counterclockwise rotation or large mandibular advancement procedures are known to experience worsening of symptoms. Figure 70.16 is the Boston University Protocol for the management of facial asymmetry requiring orthognathic surgery with pre-existing TMD [29].

#### **70.3.9 Nuclear Medicine Imaging Modalities (Scintigraphy)**

A bone scan is a nuclear imaging test that involves injecting a small amount radiotracer that into the bloodstream. The radiotracer travels through the area being examined and gives off radiation in the form of gamma rays which are detected by a special gamma camera and a computer to create images of your bones. Thus, skeletal scintigraphy offers the potential to identify disease in its earliest stages as it is able to identify any abnormal increases in metabolic activity [31].

Cisneros frst used bone scintigraphy to study mandibular asymmetry in patients [31]. There are two types of bone scan techniques commonly used: skeletal scintigraphy [subtypes: planar bone scanning and single-photon emission-computed tomography] using technetium-99m methylene diphosphate and positron emission tomography [subtypes: with and without CT, full ring and half ring] using radiolabeled 18F-2 fuoro-2-deoxyglucose [glucose analog].

Planar [regular] scintigraphy is not very accurate as it is only a two-dimensional assessment of three-dimensional anatomy. On the other hand, SPECT [single-photon emission computed tomography] allows three-dimensional assessment as the isotope is dispersed in the subject's body thus allowing spatial localization of the pathology in the mapped body organ.

Dedicated/full-ring PET [as compared to half-ring PET] provides better spatial resolution than a planar bone scanning and SPECT (Refer Fig. 78.13) because of its narrower electronic collimation [full width half maximum (FWHM) central resolution for PET being 6 mm compared with 11 mm

for SPECT] [21, 32, 33]. As the condylar growth plate is thin, PET gives an advantage to identify pathologies like condylar hyperplasia. Important factors to be taken into account when assessing

a bone scan:

	- The growth in type 1 condylar hyperplasia is only slightly faster than the normal condylar growth rate. Therefore, the difference in intensity of radiotracer uptake between a normal and affected condyle is negligible.
	- The cellular growth activity is confned to a narrow band at the normal growth center resulting in low uptake of the radiotracer.
	- Condylar hyperplasia type 1A cases: It is diffcult to differentiate CH type 1A from normal growth as it a bilateral condition with both joints involved.
	- Condylar hyperplasia type 1B cases: As this is a unilateral condition, it is easy to identify clinically. There has to be a difference in activity of at least 10% between the affected side and the normal side for a diagnosis of asymmetric growth activity/unilateral condylar involvement to be made.
	- It is easy to diagnose on the bone scan as it is usually a unilateral condition with a tumorous rate.
	- There is diffuse cellular activity throughout the tumor in the condylar head which makes it easier to diagnose on the bone scan.

#### **70.4 Clinical Considerations**

#### **70.4.1 Occlusal and Orthodontic Considerations**

Asymmetries with congenital and developmental etiology are commonly associated with dental compensations in all three dimensions as growth ensues. Rotations and crowding are

**Fig. 70.16** The fow chart outlines the Boston University Protocol for the management of temporomandibular disorders in patients who present for orthognathic surgery and has been reproduced from the article

"Nadershah M, Mehra P. Orthognathic Surgery in the Presence of Temporomandibular Dysfunction. What Happens Next? Oral Maxillofac Surg Clin North Am. 2015; 27(1):11–26" [29]

seen in hypoplasia cases such as hemifacial microsomia, and spacing and cross bites can be encountered in case of overdevelopment such as condylar hyperplasia. Transverse growth discrepancies also result in different arch shapes and Bolton discrepancy. Also, the extent of maxillary asymmetry should be accounted for, as maxilla tends to be ignored in obvious mandibular asymmetry. Thus, pitch, yaw, and roll need to be adjusted or decompensated keeping the surgical movement in mind [34]. Pre-surgical orthodontic treatment in patients with facial asymmetry must include the following:

(a) The presence of a dental and facial midline mismatch indicates a discrepancy in the yaw of the affected jaw[s]. Midline correction at the time of orthognathic surgery provides the best results.


#### **70.4.2 Growth and Development of the Craniofacial Skeleton**

Importance of understanding growth of the maxillofacial skeleton in an individual presenting with asymmetry cannot be emphasized enough. Almost half of the asymmetries are either due to an underdevelopment or an overdevelopment of the TMJ resulting in a deviated mandible in the vertical or antero-posterior direction or both of the involved side or the contralateral side. If this development takes place in the growing period, the maxilla follows the deviation of the mandible. Interceptive orthodontics can be applied in growing areas to arrest or limit the extent of asymmetry of the maxilla and mandible [35]. However, surgical intervention is generally needed after completion of growth period for the fnal skeletal and dental correction. Surgical treatment performed before growth completion is unpredictable on account of the continual growth that the patient experiences till skeletal maturity and as such is reserved only for those cases suffering from extreme functional, aesthetic, and psychological problems. Additional surgery may be needed to correct the recurrent asymmetry. Thus, timing of surgery relies very much on the growth completion.

Serial cephalometric radiographs, scintigraphy, and SPECT scans are useful to assess growth potential. The absence of activity in the TMJ and other areas helps the surgeon to proceed for corrective orthognathic surgery. The second factor for determining the timing of treatment is the progression of the asymmetry. If the asymmetry is progressive like condylar hyperplasia, it is better to wait or perform high condylectomy to check any further asymmetric growth. On the contrary, non-progressive asymmetries such as hemifacial microsomia, treatment can be initiated in early years [36]. Comparably, early surgery has usually been performed for individuals with marked malformations such as plagiocephaly, cleft lip and palate, and/or severe functional burden (e.g., increased intracranial pressure, severe obstructive sleep apnea, etc.). Lastly, in few cases of acquired asymmetry such as tumor resection, "wait-and-watch" policy needs to be adopted to eliminate chances of recurrence before a defnitive reconstruction can be planned.

### **70.4.3 Role of Functional Orthopedics and Interceptive Orthodontics**

Functional orthopedics play a substantial role in congenital asymmetries, the greatest example being nasoalveolar molding in cleft lip and palate cases to bring the maxillary segments into a more desirable position prior to surgery. Growth modifcation with the use of functional appliances is directed toward eruption of the dentition in a more favorable position and prevents worsening of the skeletal asymmetry exacerbated during growth period. Functional therapy is also aimed at maintaining the condyle in a more anatomical position to allow further growth in a symmetrical pattern. Studies have shown that an asymmetric lateral force during the growth period results in growth modifcation by infuencing the morphology of the mandibular bone and the overlying masseter muscle. Occlusal splints can be fabricated to allow for mandibular shifts toward midline, and open bite can be created to eliminate canting. This is especially helpful in hemifacial microsomia and TMJ ankylosis cases. Patient compliance is a prerequisite in functional therapy cases. Also, keeping in view the growth potential, longterm follow-up is always warranted.

#### **70.4.4 Role of TMJ and Considerations for Treatment**

TMJ is the driving force in the development of an asymmetry. Although the role of condylar cartilage has been proved to be secondary in mandibular growth and development, any pathological change leading to under- or overdevelopment can cause severe progressive asymmetry. As mentioned, TMJ-related asymmetries can be categorized as underdevelopment or overdevelopment of the condyle and in some cases both. Pseudo-asymmetry occurs due to lateral shifts on account of dental pre-maturities. Kaban and Pruzanksy have also graded hemifacial microsomia (Refer Chap. 78) based on the anatomy of the ramus condyle unit [RCU] and the glenoid fossa which make up the TMJ [36, 37]. Management of the TMJ pathology should be performed initially following which any skeletal correction should be attempted. Failure to do so has led to relapse due to the unpredictability of TMJ behavior and growth. Clinical and diagnostic imaging should be performed prior to any asymmetry correction to assess the status of TMJ. CT scans are a must for assessment in all three axes, as TMJ tumors like osteochondroma may not be discernible on 2D imaging. High or low condylectomy, ankylosis release, and RCU reconstruction should be done prior or simultaneously with orthognathic surgery. Distraction osteogenesis has also been used for neo-condyle formation. Alloplastic reconstruction of the TMJ is the most recent advancement with stable long-term results. The rationale for TMJ reconstruction is to provide a functional stable and reproducible movement which is harmonious with the stomatognathic system. Asymmetrical patients have also been found to have a higher incidence of condylar morphological changes and temporomandibular disorders on the affected side. Over time, due to the imbalance of masticatory loads and poor jaw function, the TMJ of the unaffected side also displays similar pathological changes [38].

#### **70.5 Treatment Planning**

Following issues need to be considered before planning orthognathic surgery (Box 70.2):

#### **Box 70.2 Issues that need to be considered before planning orthognathic surgery**


#### **70.5.1 Single Jaw Versus Bi-Jaw Surgery**

Facial asymmetries are rarely corrected by single jaw surgery. When the amount of discrepancy is excessive, it is best treated by dividing the overjet as well as the cant between the two jaws to achieve optimal results. During growth in congenital and developmental cases, maxilla follows and is equally involved as the mandible. Thus, it is prudent to do a bi-jaw surgery. Also, in cleft maxillary hypoplasia cases, differential maxillary advancement with simultaneous setback is the treatment of choice. We have presented a case where simultaneous maxillary distraction was done with mandibular setback. Owing to the presence of a cleft, maxilla has severely deviated midline with an extreme reverse overjet. In such cases, maxillary distraction allows slowly advancing the maxilla and simultaneously correcting the midline by distracting more on the defcient side [39] (Fig. 70.17a–c). Segmental osteotomies or differential surgically assisted rapid palatal expansion (SARPE) might also be needed in some cases to correct transverse asymmetry (Fig. 70.18a–c). Additionally, bone contouring of the mandible and zygoma may be needed to reduce the hyperostotic bone to achieve a harmonious facial contour. This is true in case of hemifacial hypertrophy and hemi mandibular hyperplasia. Similarly, additional augmentation of paranasal areas, malar prominence, and angle of mandible augmentation are frequently indicated in hypoplasia cases.

#### **70.5.2 Mandible First Versus Maxilla First Approach**

Either of the surgical sequences can produce similar outcomes when properly planned and executed in the vast majority of bimaxillary cases. Mandible frst approach is specially mentioned here as it is important in Class 3 asymmetries. Firstly, in cases where maxilla may be hypoplastic, especially in the syndromic cases of mandibular hyperplasia, rigid fxation of maxilla and down-grafting may not give stable results. Thus mandible should be fxed frst, then maxilla. Secondly, because of differential load on the TMJ, CO-CR discrepancy exists, and it is diffcult to achieve a stable centric. In such cases fxing the mandible frst is benefcial [40]. Lastly, Class 3 asymmetries are associated with concomitant TMJ pathologies, hence TMJ surgeries such as high condylectomy may be needed to be performed simultaneously, in such cases, and mandible frst approach is generally the preferred choice.

#### **70.5.3 Surgery First Approach** (Refer Chap. 67)

The surgery frst approach [SFA] came about as there was a need for immediate aesthetic improvement with shortening of the overall duration of treatment. However, it should be known that not all cases fulfl the criteria for SFA [e.g., fat curve of Spee and minimal crowding and rotations]. The total treatment duration can be shorter than the conventional three-staged surgical orthodontic treatment owing to the lack of need of pre-operative orthodontics and the subsequent post-surgical "regional acceleratory phenomenon." However, reliability of SFA is still questionable, especially in more complex dentofacial deformities, like facial asymmetry.

Park et al. reported no signifcant differences in postoperative stability between SFA and OFA after bimaxillary surgery in skeletal class III malocclusion patients [41]. In SFA, vertical dimension in surgical occlusion can increase due to occlusal interference and lead to postoperative counter clockwise rotation of the mandible as occlusal settling progresses during the postoperative orthodontic period. This may contribute toward greater postoperative mandibular forward movement.

#### **70.5.4 Modifcations in Surgical Technique for Asymmetry Cases**

The bilateral sagittal split osteotomy is the commonly used technique in asymmetry cases. It is highly fexible and adaptable in all movements. The three-dimensional anatomy of the mandible must be retained when planning a BSSO. According to Schwartz, three types of surgical move-

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**Fig. 70.17** Case of cleft maxillary hypoplasia who underwent maxillary distraction using internal device. (**a**) Pre-operative profle photo showing retruded midface, (**b**) post-operative profle photo showing good midface fullness, (**c**) post-distraction lateral cephalogram showing distractor in-situ

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 70.18** (**a**) View of the maxillary study model. (**b**) Osteotomy cut marked for SARPE. (**c**) Fixation done using miniplate only on left side. This is done to ensure expansion of the only the right side on activation of appliance

**Fig. 70.19** (**a**) When an asymmetric case is viewed along the vertical axis, areas that require immediate bone removal become obvious. Heavy interferences will take place anteriorly on the long side and posteriorly on the short side; (**b**) After the condyle is seated, premature bone contact is noted posteriorly. The area proposed for additional bone

ments can be planned with BSSO in asymmetry cases: in case of a normal overjet and overbite, differential movements will be made that is setback on the long side and advancement on the short side. In Class II asymmetry, in order to achieve symmetrical advancement, there will be a longer advancement on the short side than on the long side and lastly in Class III cases, there will be a larger setback on the long side than on the short side. During surgery, the distal segment rotates from the short side to the long side as the midline is corrected (Fig. 70.19a). Selective bone removal from the area of interferences should be done before the distal segment has been passively repositioned. Bone is removed from the anterior and medial aspects of the proximal segment until there is broad contact along segments. On the short side, frst contact will occur posteriorly [42]. Bone is removed from the medial aspect of the proximal segment posteriorly (Fig. 70.19b, c). This is done to reduce condylar torque during rigid internal fxation to ensure stability of the movement. Figures 70.20a−d and 70.21a, b show a case of unilateral condylar elongation treated with differential BSSO.

removal is indicated by the dotted line; (**c**) Good bone contact has been achieved. Image Source: Schwartz HC. Effcient surgical management of mandibular asymmetry. J Oral Maxillofac Surg. 2011 Mar;69(3):645– 54. doi: 10.1016/j.joms.2009.03.009. Epub 2010 Oct 8. PubMed PMID: 20934795 [42]

#### **70.5.5 Soft Tissue Interventions**

The asymmetrical growth of soft tissues may lead to residual soft tissue asymmetry even after correction of the underlying bony deformity. Furthermore, some asymmetrical craniofacial regions cannot be corrected by means of conventional surgical techniques. Adjunctive soft tissue procedures [e.g., dermis fat transplant, autologous fat transfer, microvascular adipose free faps] might be indicated to achieve bulk in defcient soft tissue deformities such as Parry Romberg syndrome, TMJ ankylosis, etc. Alloplasts such as Medpore, silicone, nanogels, tissue expander, etc. have also been used with varying degrees of success (Sect. 70.7 "Case Scenarios").

#### **70.5.6 Distraction Osteogenesis** (Also refer Chap. 87)

Distraction osteogenesis is the process of native bone formation via traction of osteotomized segments. On account of distraction histogenesis, simultaneous soft tissue and

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 70.20** (**a**–**d**) Clinical and radiographic images showing a case of image showing severe facial asymmetry with unilateral condylar elongation on the right side. (**a**) frontal photo, (**b**) profle photo, (**c, d**) lateral and frontal views on volume rendered 3D CT scan

hard tissue augmentation can be achieved. Adequate amounts of advancements can be achieved without any soft tissue limitations. Various cases have been treated successfully with DO that are presented in this chapter. DO has various advantages over conventional osteotomies in complex facial asymmetries. Pre-arthroplastic distraction in ankylosis-related asymmetries has been reported to have excellent results [43]. This is because simultaneous distraction of skin, muscle, and tissue takes place with bone regeneration. Thus, better esthetics are achieved without any need for additional soft tissue procedures. Distraction is often the only procedure of choice in large advancements, rate of relapse is signifcantly lower, and results are much stable. Figures 70.22a−e, 70.23a, b, 70.24a−d and 70.25a−g show a case of facial asymmetry secondary costochondral graft resorption in a case of TMJ ankylosis, treated with stage one distraction osteogenesis followed by defnitive correction with BSSO.

(Also refer Figs. 78.43, 78.44, 78.45, 78.46, 78.47, 78.48, 78.49, 78.50, 78.51, 78.52, and 78.53 for management of facial asymmetry cases due to Hemifacial microsomia and Traecher Collins syndrome).

**Fig. 70.21** Same patient as in Fig. 70.20 demonstrating corrected facial midline and mandibular prognathism postoperatively (**a**) frontal view, (**b**) profle view

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#### **70.6 Conclusion**

Facial asymmetry is a three-dimensional facial deformity having multiple etiologies. Complete and thorough knowledge of the etiological factors, the progressive nature of the asymmetry plays a crucial role in formulating a treatment plan. Growth and development of the individual and timing of intervention is the single most important factor affecting the stability of results in any form of asymmetry. Severe relapses could occur if the exact cause of asymmetry is overlooked and treatment is attempted before completion of growth [44, 45].

**Acknowledgment** Gratitude and acknowledgments to Dr. Harsh Desai and Dr. Shibani Nerurkar for their sincere efforts in collection of data and editing of the contents.

DisclosureAuthors have no fnancial conficts to disclose.

#### **70.7 Case Scenarios**

#### **Case 1: Condylar Hyperplasia with Concomitant Masseteric Hypertrophy** (Figs. 70.26a, b, c, 70.27a, b, 70. 28a, b and 70. 29a, b)

A 27-year-old female patient reported with a complaint of a progressive facial asymmetry and an appearance of fullness over the left angle of the mandible.

On examination, the patient had a tapered, triangular shape of the face with an obvious facial asymmetry which was evident along with elongation of the right side of the face and fullness over the left angle region (Fig. 70.26a). The mandible revealed bowing on the right side with a mild symphysis kink. TMJ on palpation revealed mild clicking on the right side and otherwise equal movements along with unrestricted mouth opening was noted. On assessing the left angle region, an outward projection was noted due to the underlying hyper functioning of the masseter muscle. On clenching, signifcant enlargement of the involved muscle was seen as compared to the contralateral side (Fig. 70.26b).

Intraoral examination did not reveal any occlusal cant (Fig. 70.26c). There was an absence of cross bite/open bite, on either side, along with a stable occlusal relationship. The dental midlines were coincident with the skeletal midline and with each other too. No other dental abnormalities were evident on examination.

Imaging studies revealed mild degree of defection of the chin and mandible toward the left side (Fig. 70.27a, b). Transverse mandibular asymmetry was reported. The condylar head appeared to be irregularly deformed, while the neck on the right side appeared broader as compared to the left side. The ascending ramus appeared elongated with a rounded gonial angle. The mandibular lower border was bowed downward and positioned lower on the right side as compared to the left side. The distance between the tooth 1566

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**Fig.70.22** (**a**–**e**) Case of facial asymmetry post-TMJ ankylosis treatment, due to resorption of costochondral graft. Note the exposed screw intraorally. Left side of mandibular arch fully telescoped inside the maxilla. (**a**) basal view showing gross asymmetry, (**b**) patient retaining good mouth opening after surgery for anlykosis, (**c**) Antero-posterior skull view showing asymmetry on the left side with screw from earlier costo-chondral graft fxation, (**d**) photograph showing trans-oral exposure of screw and (**e**) malocclusion with midline shift to the right, dental crowding and left sided lingual cross-bite

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 70.23** (**a**, **b**) Stage 1 treatment in the same patient as in Fig. 70.22, left side vertical ramus distraction to establish equal ramal height. (**a**) Initial height of ramus prior to beginning distraction, (**b**) vertical lenghtening of ramus after completion of distraction

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 70.24** (**a**–**d**) Second stage treatment in same patient as in Fig. 70.22: distractor removal with differential BSSO. (**a**) intra-operative photo from stage 1 surgery, showing osteotomy line for distraction (yellow arrow), (**b**) intra-operative photo during distractor removal demonstrating new bone formation(yellow arrow), (**c, d**) intra-operative photos showing osteotomy cuts for BSSO

roots and mandibular canal was increased with displacement of the latter towards the lower border of the mandible on the right side. The right side vertical ramus appeared relatively increased height as compared to the left. Thickened trabecular pattern was also evident on the right side.

#### **Management**

Following preparation for the administration of GA and a scintigraphy report which did not reveal an active mandibular hyperplastic condyle on the right side, the patient was prepared to be taken up for the procedure of an intraoral inferior border osteotomy. An intraoral vestibular incision was taken from 33 regions up to the external oblique ridge on the right side. Complete degloving was done to expose the inferior border in the anterior, body, and angle region of the mandible on the right side. Care was taken to identify the mental foramen and salvage the nerve. Methylene blue ink was used to mark the osteotomy line extending from the right central incisor posteriorly up to the angle region (Fig. 70.28a). It was correlated with the position of the neu-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 70.25** (**a**–**g**) Pre- and postoperative photographs of the same patient as in Fig. 70.22, showing restoration of symmetry and midline (**a, b**) pre and post-operative frontal photographs showing correction of asymmetery, (**c, d**) pre and post-operative profle photographs demonstrating increased vertical height of ramus, (**e**) pre-treatment intra oral

occlusion demosntrating severe shift in the dental midline with lingual crossbite on the left side, (**f**) orthodontic strap-up for dental and arch alignment, (**g**) post-treatment occlusion showing good dental rehabilitation

rovascular bundle, so as to prevent any damage to the same. The cut was initiated with a fne fssure bur under copious saline irrigation extending from buccal cortical plate to lingual cortical plate. With the help of an osteotome, the anterior cut was completed, and the lower inferior hyperplastic border was removed in one piece (Fig. 70.28b). The raw surface was smoothened with a vulcanite bur, and contouring was done to match the normal left side. The wound was closed in two layers with interrupted sutures using 3-0 vicryl. The surgical site was fushed with 2% povidone iodine solution.

For the masseteric hypertrophy on the left side, Botox [botulinum toxin Type A, Allergan™] powder was reconstituted with normal saline solution, pushed within the vial, and 30 units of it were administered using an insulin syringe and 30 gauge needle within the substance of the muscle, divided equally at three sites in a triangular fashion (Refer Chap. 33 and Fig. 33.10 for details on Botox injection to treat masseteric hypertrophy).

Complete correction of facial asymmetry with left side masseteric hypertrophy and right side condylar hyperplasia features was achieved with this surgical method (Fig. 70.29a, b).

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**Fig. 70.26** (**a**, **b**) Frontal and profle views showing facial asymmetry due to condylar hyperplasia of the right side. (**c**) Occlusal view showing dental cant on account of condylar hyperplasia

#### **Case 2: Parry Romberg Syndrome** (Figs. 70.30a, b, 70.31a, b, 70.32a, b, c, 70.33a–h and 70.34a–f)

An 18-year-old female patient reported with gradual disfgurement and shrinkage of the right side her face since last 8–9 years.

Clinical examination revealed an asymmetry of the face on the right side with a marked atrophy of facial soft tissue (Fig. 70.30a). Signifcant orbital dystopia along with a hypoplastic soft tissues in the right, evident on worm's view (Fig. 70.30b). Clinically, a deformed and hypoplastic upper lip was seen with an increased vermillion show of the lower lip, resulting in a slanting rima oris. The right commissure, right ala of the nose, and the right supraorbital ridge region revealed obvious depression.

Intraoral examination revealed a missing upper right permanent canine along with crowding in the premolar region. Alveolar height in the maxillary right premolar region was reduced which was a pathognomonic sign of Parry Romberg (Fig. 70.31a, b). The occlusion was deranged, with a shift of the dental midline to the right.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 70.27** (**a**) PA mandible showing inferior border bowing on the right side and kink in chin region (yellow arrows) which stops at the midline. (**b**) 3D CT shows mild degree of tilting of chin and mandible toward the left side

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 70.28** (**a**, **b**) Inferior border osteotomy to remove the excessive contour below the mental nerve

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**Fig. 70.29** (**a**) Pre- and (**b**) post-op correction in facial asymmetry. Reduction of fullness on left side and centralization of chin

Imaging studies revealed some degree of hypoplasia of mandible, zygoma, and maxilla on the right side. Presence of impacted permanent right maxillary canine was evident. The body-angle ramus, coronoid, and condylar process however appeared normal. Alveolar height was reduced in the right maxillary premolar region (Fig. 70.32a, b, c).

#### **Management**

The patient was prepared for GA administration for correction of facial asymmetry. A camoufage technique was planned wherein multiple Medpore© implants were used to fll up the defcient areas on the right side of her face in the right supraorbital, right maxillary alveolar region in the canine, and premolar areas right parasymphysis region of the body of mandible and right side chin along with autologous lipo transfer to increase the volume of the upper lip. Two separate small incisions were taken in the submandibular region anteriorly and posteriorly keeping the intervening skin and tissues intact. Layerwise dissection was done to reach the angle, body, and the anterior regions of the mandible. Tunnelling was done between the two incisions so as to receive the pre-shaped Medpore© implant, which was inserted from the anterior site and was pushed posteriorly to sit on the body, angle, and a portion of the ramus. The implant was notched in the superior aspect, in the region of the mental nerve to prevent impingement of the same. Four long titanium screws were used to fx the Medpore© implant on the body of the mandible on the right side (Fig. 70.33a). An additional half chin implant was placed to augment the defcient chin on the right side for achieving symmetry and was fxed with 2 long titanium screws (Fig. 70.33b). The incision sites were closed in two layers.

Another lateral eyebrow incision was taken on the right side (Fig. 70.33e). Dissection was done to expose the supraorbital rim. Supraorbital foramen and nerve were identifed. An infra-orbital rim Medpore© implant for the right side was inverted and placed on the right supraorbital region to augment this defcient area. Two long titanium screws were used to stabilize the Medpore© implants.

Intra-orally a vestibular incision was taken in the right premolar and canine region. A full-thickness mucoperiosteal fap was raised. The infra-orbital nerve was identifed and protected. A paranasal Medpore© implant was fxed with 1 long titanium screw to give fullness in this region. The wound was sutured in two layers with 3-0 vicryl.

Periumbilical and medial thigh regions were prepared to harvest fat cells. Manual aspiration of the fat cells was done. Following the simple method of sedimentation, the fat cells were separated from the blood components (Fig. 70.33f). 2 mm incisions were taken on either side of the oral commissure. A large 16 gauge epidural needle attached to 10cc syringe was used to push the fat within the substance of the upper lip from either side (more on right side than on the left) increasing the

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**Fig. 70.30** (**a**) Frontal view—right side reveals marked atrophy in the distribution of all three branches of trigeminal nerve. (**b**) Asymmetry of the inferior border evident on worm's-view involving soft and hard tissue

**Fig. 70.31** (**a, b**) Intraoral examination of the same patient as in Fig. 70.30, reveals reduced alveolar height (blue arrow) in the right premolar region (**a**), as compared to the left side (**b**). Alveolar height reduction is an important clinical fnding in Romberg's disease

**Fig. 70.32** (**a**, **b**) 3D CT of the patient in Fig. 70.30 reveals skeletal defciency of alveolar height on right side (blue arrow), and reduction in vertical height of the ramus and body of the mandible on right side, (**c**) left side shows normal anatomy

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 70.33** (**a**) Extra-oral incisions—submandibular incisions made anteriorly and posteriorly. Medpore implant in ramus and body fxed with four titanium screws. (**b**) Additional half chin implant fxed with two titanium screws on right side of chin region. (**c**) Paranasal and alveolar Medpore implant fxed through intra-oral approach with titanium screws. Infraorbital nerve protected. (**d, e**) Use of Medpore implant for right side supra orbital rim. Notch placed superiorly to protect the supraorbital nerve. (**f**) Sedimentation to separate fat cells from blood components. Harvesting autologous fat grafts. (**g**) Introduction of fat cells into the upper lip through needle prick in right commissure. (**h**) Overcorrection achieved on table

volume of upper lip (Fig. 70.33g). A stitch on either side of the commissure was taken to prevent escape of fat cells (Fig. 70.33h). Overcorrection was done on table. Postoperatively, good facial symmetry was achieved with fullness at the defcient site using fat and implant (Fig. 70.34a−f).

For further case scenarios on management of facial asymmetry refer Figs. 68.19 and 68.38, in Chap. 68 on mandibular orthognathic procedures and Figs. 69.30, 69.31, 69.32 and 69.40 in Chap. 69 on maxillary orthognathic procedures.

**Fig. 70.34** (**a**–**f**) Comparison of pre and post op results after 4 years. Satisfactory correction in facial asymmetry achieved. Pre (Fig. 70.30a) and post treatment frontal photographs (**a, b**) oblique facial views (**c, d**) and basal views (**e, f**) demonstrating better soft tissue balance and symmetry

©Association of Oral and Maxillofacial Surgeons of India

#### **References**


#### **Additional Reading**

Grummons DC, Kappeyne van de Coppello MA. A frontal asymmetry analysis. Journal of Clinical Orthodontics: JCO. 1987;21(7):448–465.

**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Obstructive Sleep Apnea Syndrome**

Suresh Menon

#### **71.1 Introduction**

Obstructive sleep apnea (OSA) is a condition that affects 2–4% of the adult population. This disease has reached a proportion of increasing importance due to its neurological and cardiological consequences. Abnormal pharyngeal anatomy and altered activity of the upper airway musculature dilator physiology are primarily responsible for the collapse of the pharyngeal walls during sleep.

#### **71.2 Defnition**

OSA is defned by the occurrence of daytime sleepiness, loud snoring, witnessed breathing interruptions, or awakenings due to gasping or choking in the presence of at least fve obstructive respiratory events (apneas, hypopneas, or respiratory effort-related arousals) per hour of sleep [1].

When OSA is accompanied by excessive daytime sleepiness, it is termed Obstructive Sleep Apnea Syndorme.

The common terms that are used in OSA are apnea, hypopnea, apnea hypopnea index (AHI), and respiratory distress index (RDI) [2].


increasing respiratory effort for 10 or more seconds leading to an arousal from sleep but not meeting the criteria of an apnea or hypopnea [3].

#### **71.3 Etiopathogenesis**

The upper airway is a fexible structure consisting of muscle and fat tissue and is usually only passively supported by bones. Therefore, it can be easily infuenced by soft tissue factors like fat deposition in the parapharyngeal structures, edema/infammation of the parapharyngeal region, hypertrophy of adenotonsillar tissues, or enlarged tongue.

The primary actor in the pathophysiology of OSA is the narrow, foppy upper airway. There is increased resistance of the upper airway due to anatomic factors that creates a negative airway pressure. This results in impaired function of airway-dilating muscles, thus increasing collapsibility. During sleep, the loss of skeletal muscle tone narrows the upper airway, making it foppier, especially during rapid eye movement (REM) sleep when muscle relaxation is intense. This results in two signifcant actions:


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S. Menon (\*)

Department of Oral and Maxillofacial Surgery, Vydehi Institute of Dental Sciences and Research Centre, Bangalore, India

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_71

Additional factors that can increase the severity of upper airway resistance during sleep are mouth opening or a supine posture which allows the gravitational forces to push the tongue and soft palate back. Upper airway resistance can occur anywhere from the nasopharynx to the hypopharynx but primarily involves the oropharynx (Fig. 71.1).

#### **71.4 Risk Factors for OSA**

#### **71.4.1 Age**

The disease prevalence increases steadily with age and reaches a stable level after the age of 60 years. The probable explanations for the age-related increase in prevalence include increased fat deposition in the parapharyngeal area, soft palate lengthening, etc.

#### **71.4.2 Excess Body Weight**

Body weight is an important risk factor for OSA, and studies have endorsed the positive effects of dieting and surgical weight loss on reducing OSA. Body weight increase can affect normal upper airway mechanics during sleep through:


**Fig. 71.1** Areas causing OSA

#### **71.4.3 Gender**

It is an established fact that men are more vulnerable than women toward developing OSA. The differences exist not only in prevalence but also in polysomnographic characteristics of sleep and breathing patterns. Women were seen to have a lower AHI in non-rapid eye movement (non-REM) sleep. Disordered breathing events in women have a shorter duration and are associated with less oxyhemoglobin desaturation than in men.

#### **71.4.4 Craniofacial Anatomy**

The mechanical properties of the upper airway and the tendency to collapse during sleep can be infuenced by both hard and soft tissues in the region. Findings in the craniofacial region like large tongue or soft palate, reduced mandibular size, or tonsillar hypertrophy in addition to inferiorly placed hyoid, maxillary, and mandibular retropositioning can narrow upper airway dimensions and leading to episodes of apneas and hypopneas during sleep.

#### **71.4.5 Familial and Genetic Predisposition**

Inheritance and familial factors also play a major role in OSA. First-degree relatives of OSA patients seem to be at risk more likely than others. The familial susceptibility tends to increase directly with the number of affected relatives.

Heredity and genetic factors also have been found to have a role in determining the volume of the lateral parapharyngeal

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walls, tongue, and total soft tissue structures. A detailed family history can help in identifying those that have the disorder but remain undiagnosed.

#### **71.4.6 Smoking and Alcohol Consumption**

Cigarette smoking and alcohol are also possible risk factors for obstructive sleep apnea. Airway infammation can occur due to cigarette smoke that could modify the properties of upper airway and increase its collapsibility during sleep. Alcohol consumption before sleep increases upper airway collapsibility and the precipitate apneic and hypopneic episodes during sleep. Another effect of alcohol is to inhibit respiratory motor output to the upper airway, causing hypotonia of the oropharyngeal muscles.

#### **71.4.7 Medical Comorbidity**

There is enough evidence to suggest that OSA can be a factor in the development of hypertension, coronary artery disease, congestive heart failure, and stroke [4].

OSA is also associated with diabetes mellitus, Therefore, diagnosing the condition and intervening early could directly or indirectly enhance glycemic control [5]. The role of positive airway pressure (PAP) therapy could result in reduced day time fatigue, better physical activity, resulting in improved metabolic control.

#### **71.5 Clinical Sequelae [6]**

#### **71.5.1 Endocrine and Metabolic Efects**

The central effects of sleep fragmentation and hypoxemia have been seen to induce a reversible neuroendocrine defect in growth hormone and testosterone secretion. This may explain impaired growth seen in children with upper airway obstruction which seems to get better after adenotonsillectomy.

#### **71.5.2 Neuropsychological and Social Consequences**

The classic feature of OSA prevalent as excessive daytime sleepiness may lead to both impaired work performance and driving. OSA patients seem to perform poorly on psychometric tests, and improvement has been seen after nasal CPAP therapy.

#### **71.5.3 Cardiovascular Sequelae**

There are two serious consequences of OSA involving the cardiovascular system. Initially acute cardiovascular changes occur during an apnea. This is followed by more chronic cardiovascular conditions like hypertension, myocardial infarction, stroke, and death.

#### **71.6 Epidemiology [7, 8]**

OSA has no specifc age predilections, but a study by Young et al. estimated the prevalence in middle age to be 4% for men and 2% for women. Their study estimated that 1 of every 5 adults has at least mild OSA and 1 of every 15 has at least moderate OSA.

#### **71.7 Diagnosis [1]**

A detailed study of clinical signs and symptoms established during a comprehensive sleep evaluation and fndings identifed by sleep testing lead to the diagnosis of OSA.

#### **71.7.1 History and Physical Examination**

The diagnosis of OSA begins with a sleep history in one of three settings:


Of the available, the Epworth sleepiness scale (ESS) (Table 71.1) is a popular subjective-based self-assessment of sleepiness that determines the degrees of sleepiness [9]. When scores are greater than 10, further investigations are recommended. However as about 10% of the population have a score of 11 or more, this score should be complemented by a narrative confrmation of intrusive somnolence.

#### **71.7.2 Polysomnography (PSG)**

This is an overnight sleep study monitored by a sleep technologist and is considered the "gold standard" in sleep medicine (Fig. 71.2). The physiologic parameters measured during PSG include simultaneous monitoring of

#### **Table 71.1** Epworth sleepiness scale


brain wave activity continuously, eye movements, muscle activity of the legs and mandible, body position, heart rate and rhythm, blood pressure, snoring, and respiratory activity including breathing patterns and oxygen saturation. A detailed analysis of these can reveal apneic, hypopneic activities, etc.

Presence of obesity or signs of upper airway narrowing should also be documented.

#### **Patients at High Risk for OSA and Who all should be evaluated for OSA Symptoms [1]**


#### **OSA Symptoms That Should Be Evaluated During a Comprehensive Sleep Evaluation**


#### **71.7.3 Imaging Aids**

#### **71.7.3.1 Cephalometrics**

There is a plethora of imaging aids to help diagnose and plan the management of OSA. Cephalometrics has been the oldest imaging modality in the diagnosis of OSA. However, its role in quantifcation of the pharyngeal volume is controversial as the image that is two-dimensional is used to evaluate a three-dimensional structure [3].

It is a known fact that the lateral pharyngeal wall collapse has a bigger infuence on severe sleep apnea than retropalatal and retrolingual collapse as studied with dynamic MRI, and this would not appear evident on a lateral cephalogram [10]. Another shortcoming of lateral cephalograms is that they are taken with the patient upright and awake and therefore do not characterize the asleep or supine airway.

Cephalometric images however have other advantages that can be used to predict OSA. It can be used to measure the upper airway length (UAL) (Fig. 71.3). UAL is signifcantly longer in OSA patients due to the relation between UAL and airfow resistance. Since the part of the airway is primarily composed of the soft tissues compared to the more rigid, cartilaginous, subglottic airway, this region may predispose to collapse. Studies have proved that male patients with UAL ≥ 72 mm have an eightfold increase in the probability of OSA while females with UAL ≥ 62 mm have a fvefold increase in OSA probability [11].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 71.2** Polysomnography leads and parameters. *EEG* Electroencephalogram, *EOG* Electrooculography, *EMG* Electromyography, *ECG* Electrocardiography

Cephalometrics can also be used to predict the success in multilevel phase I therapy for patients. Skeletal class II patients with a more retrognathic mandible are poor responders. Other patients who could be poor responders include those with hyperdivergent vertical pattern with a larger mandibular plane angle, longer lower facial height, and steeper occlusal plane [9].

#### **71.7.3.2 Dynamic Upper Airway Imaging [12]**

Dynamically assessment of the level of upper airway obstruction in OSA patients will allow targeted intervention and allow planning a specifc surgical procedure by allowing a delineation of the site and specifying degree and pattern of obstruction. It can also be used to exclude pathology like tumors. Dynamic sleep MRI and drug-induced sleep CT scan characterize the airway in OSA with the advantage of ability to evaluate the airway in a multiplane fashion in the sleeping state or a simulated sleep state.

Drug-induced sleep endoscopy (DISE) is an alternative to conventional endoscopy with the goal of more accurately representing patterns of collapse during the sleeping state.

#### **71.7.3.3 Acoustic Refex Ion Test**

In this test, sound waves are projected into the airway and are refected into the tube to a computer which creates an image that determines the location of obstruction. This can also predict the effect of mandibular advancement and protrusion on upper airway.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 71.3** Narrowing of oropharynx and long upper airway length in OSA

#### **71.8 Clinical Features (Tables 71.2 and 71.3)**

#### **71.9 Treatment Modalities**

OSA is a chronic condition that would require multidisciplinary management over a long period of time. There is a myriad of options to treat the condition ranging from behavioral to medical to surgical options. The success of treatment would have to ensure the voluntary active participation of the patient.

#### **71.9.1 Positive Airway Pressure [13]**

Continuous positive airway pressure (CPAP) is usually the frst line of treatment for OSA. It works on the principle of binding the upper airway in an open position to improve patency during sleep (Fig. 71.4).

This was frst described by Sullivan [14] in 1981. The pneumatic splinting action is effective in reducing the AHI. PAP may be delivered in either continuous (CPAP), bilevel (BPAP), or auto titrating (APAP) modes. CPAP is the frst line of treatment for moderate to severe OSA and may be used occasionally in mild OSA. CPAP has also found to be effective as an adjunctive therapy to alter blood pressure in OSA patients having hypertension.

Some of these patients may elicit intolerance for CPAP therapy. In these cases, BPAP, pressure relief, or APAP can be considered as an alternative. In addition to its splinting

#### **Table 71.2** Symptoms of OSAS


#### **Table 71.3** Signs of OSAS


action, CPAP increases vagal tone, cardiac output, and stroke volume and decreases systemic vascular resistance, and there is reduced risk of cardiovascular mortality.

Compliance with nasal CPAP (nCPAP) ranges from 50 to 89% [15]. Reasons for noncompliance are usually due to tolerance problems like dry mouth, conjunctivitis, rhinorrhea, skin irritation, pressure sores, nasal congestion, and epistaxis. Other less common causes of noncompliance include aerophagia, chest discomfort, and bed partner intolerance or psychological problems arising from lack of motivation, claustrophobia, and anxiety.

Though there is no established known lower limit of nightly use below which nCPAP therapy is ineffective, it is suggested that 3.4 h per night of nCPAP use may be adequate to improve cognitive function and quality of life.

#### **71.9.2 Behavioral Strategies [16]**

Behavioral strategies have also been used as treatment methods in OSA. These include weight loss, regular exercise, positional therapy, and sleep hygiene which involves alcohol abstinence and consumption of sedatives before sleep.

Sleep position while supine can decrease the lateral upper airway dimensions, particularly while in the supine position.

**Fig. 71.4** CPAP usage

Therefore, in positional therapy, the patient is kept in a nonsupine position.

#### **71.9.3 Oral Appliances [17]**

The primary role of oral appliances (OAs) is to enlarge the posterior oropharyngeal airway space, leading to reduction of chances of the upper airway collapsing during sleep. They are ideally indicated in mild and moderate cases of OSA who are noncompliant/poorly compliant to nasal CPAP. Oral appliances are of two types: tongue retaining or mandibular repositioning.


protrusive capacity. This is followed by polysomnography to check the effcacy.

It is mandatory for patients using MRD to have adequate number of teeth to seat the appliance. There should not be any deleterious TMJ disorder, and the patients should have an adequate range of jaw motion and adequate manual dexterity and should be motivated to use the appliance.

The MRD device is customized and the material used is fexible polyamide.

In general, OAs are either titratable or non-titratable. Titratable OAs permit varying amounts of mandibular protrusion. Non-titratable OAs hold the mandible in a single protrusive position without any possibility to change the position during treatment. Some of the non-titratable devices are a simple splint, bionator, Karwatsky activator, or Herbst appliance [20].

#### **71.9.4 Surgical Treatment of Obstructive Sleep Apnea** [21] (Table 71.4)

Surgical procedures to correct or treat OSA essentially provide site-specifc treatment to increase airway size and decrease airway resistance, thus reducing the effort required in breathing. The site of obstruction is specifc to each patient and is as unique as fngerprints. Therefore, one needs to know which the most appropriate procedure is to guarantee success. Since no single factor is predictive of OSA, the signifcance of a thorough physical examination and imaging to

Mandibular Repositioning Device (MRD) MRD

During sleep there is restricted airway space ©Association of Oral and Maxillofacial Surgeons of India

**Fig. 71.5** Mandibular repositioning device


**Table 71.4** Common surgical procedures for OSA by site

identify the target site of airway resistance cannot be over emphasized.

increases airway space

*Tracheostomy* has been used to bypasses the upper airway and is thus a successful modality in treatment, but the morbidity associated with it limits its application.

Factors in the nasal cavity may also play a role in infuencing the pharyngeal stability through abnormalities like septal deviation and inferior turbinate. *Nasal surgery* to remove these abnormalities can improve nasal airfow, thus having a positive effect on OSA.

*Multiple surgical procedures* of the palate like uvulopalatopharyngoplasty (UPPP), which involves removal of the tonsils, uvula, and posterior velum in patients with large tonsils and relatively normal palatal position, are also good adjunctive procedures.

UPPP can also be done assisted by lasers allowing more precise incision and excision than conventional surgery. It also has the advantages of avoiding the need for general anesthesia and with minimal bleeding.

*Tonsillectomy with adenoidectomy* is the usually frst line of surgery for children with OSA without signifcant craniofacial anomalies.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 71.6** Genioglossal advancement

*Tongue reduction* is also a part of the surgical option in enlarges tongue cases where partial glossectomy can reduce the tongue volume.

Surgical procedures of the genial segment of the mandible like *Genioglossal advancement* moves the genial tubercles forward along with the genioglossus muscle, resulting in a more forwardly positioned base of tongue. In addition, it also causes the forward movement of the hyoid bone. This shift increases the posterior airway space and avoids the collapse of its walls during the REM phase of sleep. There are a lot of modifcations of the genial advancement procedures.

The standard procedure moves the whole genial segment including the chin. A modifed technique allows the surgeon to advance the genial tubercle without altering the normal anatomic position or shape of a patient's chin by only moving the rectangular bony component involving the tubercle (Fig. 71.6).

*Hyoid myotomy* involves the detachment of infrahyoid muscles and moving the hyoid forward and upward and fxing it with sutures. Another procedure moves the hyoid forward and downward with excision of the lesser cornu and fxing the hyoid anterior to the thyroid cartilage by sutures.

Surgical procedures can also be performed at different levels either concomitantly or in a staged manner. This is done when patients have more than one site of obstruction.

*Hypoglossal nerve stimulators* (HGNS) are a new addition to the armamentarium for treatment of OSA. It was approved by the FDA for treatment of moderate to severe OSA in 2014 [22].

The device which acts like a pacemaker monitors the breathing patterns and gets activated during sleep to stimulate the hypoglossal nerve, thus controlling upper airway muscles.

*Maxillomandibular advancement (MMA)* is undoubtedly the most successful surgical technique in OSA. This advantage of this procedure is the effect in correcting airway obstruction at multiple levels. The surgical advancement of the maxillomandibular skeletal framework corrects the airway collapsibility at the nasopharyngeal and oropharyngeal levels and is ideal in patients with moderate and severe OSA who exhibit multilevel obstruction.

The Le Fort I osteotomy of the maxilla along with mandibular sagittal split osteotomy is performed for advancing maxilla and mandible, thus increasing the airway space as it draws the base of the tongue and soft palate forwards (Fig. 71.7).

Achieving *MMA by distraction* is another alternative technique, especially in cases of TMJ ankylosis (Figs. 71.8 and 71.9) where a defcient mandible in the sagittal plane is primarily responsible for the obstructed airway.

The dimensions of maxilla and mandible can also be increased in the transverse plane by distraction resulting in increase in the dimensions of nasopharynx, oropharynx, and the nasal cavity along with movement of tonsillar pillars and the musculature of the velum. Maxillomandibular transverse distraction osteogenesis can be concomitantly be performed with their sagittal advancement for a more effective form of treatment MMA alone.

#### **71.10 Adjunctive Therapies**

#### **71.10.1 Bariatric Surgery [23]**

Weight loss procedures through bariatric surgery is indicated in patients with a body mass index (BMI) ≥ 40 kg/m2 or those with a BMI ≥ 35 kg/m2 with important comorbidities especially when dietary attempts are ineffective.

#### **71.10.2 Medications [23]**

Pharmacologic agents can on occasion be used with some degree of success in treating OSA by increasing glossopharyngeal neurologic activity or decreasing REM sleep.

Protriptyline, a tricyclic antidepressant reduces the frequency of apnea and desaturation in non-REM sleep and suppressing REM activity. It also increases the tone of the upper airway muscles. The anticholinergic activity of the drug however limits its use.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 71.7** Maxillomandibular advancement and its effect on the airway

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 71.8** Compromised airway in ankylosis ©Association of Oral and Maxillofacial Surgeons of India

**Fig. 71.9** Improved airway after mandibular distraction in a TMJ ankylosis case

Theophylline reduces the episodes of apneas and hypopneas, but the quality of sleep deteriorates.

Modafnil is a wake-promoting medication that can improve residual daytime sleepiness in OSA patients despite regular use of CPAP. It is however avoided in patients who are noncompliant with CPAP. The adverse effects of these drugs are headache and nervousness.

Topical nasal corticosteroids have also been recommended in patients suffering from concurrent rhinitis.

#### **71.11 Conclusion**

Obstructive sleep apnea is a multi-factorial and multi-level condition whose management needs to be customized for every patient after a correct diagnosis. Treatment is regulated starting with the non-surgical options and moving to specifc site surgical procedures depending on the area of involvement.

#### **71.12 Case Scenario**

A 12-year-old female patient with history of sleeping diffculty due to airway obstruction.

Clinical features: Retruded chin, incompetent lips, dry mouth, short chin throat distance (Fig. 71.10).

Preoperative radiographic fndings: Defcient mandible, posteriorly placed menton, narrowed oropharynx (Fig. 71.11).

©Association of Oral and Maxillofacial Surgeons of India

Treatment plan: Mandibular advancement of 10 mm by distraction (Fig. 71.12).

Post op fndings: Improved profle, no episodes of apneas hypopneas (Figs. 71.13, 71.14 and Box 71.2).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 71.11** Preoperative cephalogram

#### **Box 71.1** Preoperative PSG report


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 71.12** Mandibular distraction

©Association of Oral and Maxillofacial Surgeons of India

#### **Fig. 71.13** Postoperative profle of the patient

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 71.14** Postoperative cephalogram showing improved airway

#### **Box 71.2** Post distraction PSG report


#### **References**


#### **Suggested Reading**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

**Part XIX**

**Developmental Deformities of the Oral and Maxillofacial Region**

**72**

Pritham N. Shetty, Jaideep Singh Chauhan, Mamatha Patil, Neha Aggarwal, and Dipesh Rao

#### **72.1 Introduction**

A cleft lip [CL] is defned as a congenital defect in lip continuity due to an embryological malformation. Cleft lip and palate [CLP] have an overall incidence of 1 in 1000 live births [1]. For different ethnicities, the incidence varies. Like other facial deformities, cleft lip and palate produce a considerable degree of disfgurement and functional impairment. A comprehensive treatment involving a cleft surgeon, otolaryngologist, geneticist, speech pathologist, orthodontist and others are required at multiple stages right from infancy to adulthood. A successful lip repair requires careful consideration of presentation of the cleft, the availability of tissues or the lack thereof and effect of intervention on growth and function. We have tried to simplify this concept, keeping certain key points in mind necessary for comprehension of the subject. In this chapter, we have discussed embryology, anatomy and clinical presentation of cleft as an integrated phenomenon for better understanding of cleft lip. The author's technique of cleft lip is discussed in a stepwise manner.

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_72) contains supplementary material, which is available to authorized users.

P. N. Shetty (\*)

OMFS, Bangalore Institute of Dental Science, Bangalore, India

J. S. Chauhan

#### M. Patil

Sparsh Hospital Bommasandra Industrial Area, Bangalore, India

N. Aggarwal

Cleft and Craniofacial Surgery, Meenakshi Cleft and Craniofacial Centre, Chennai, India

#### D. Rao

Bhagwan Mahaveer Jain Hospital, Bangalore, Karnataka, India

#### **72.1.1 History of Cleft Lip Repair**

The enigma of cleft lip and the historic journey to repair the defect has been well described in the narrative book by Millard [2].The excerpts from it illustrates the documentation of the frst cleft lip repair in the year 390 AD where an unidentifed Chinese physician cut the edges of the cleft and stitched it together with a postoperative order of limited lip movements for the next 100 days. The need to identify an ideal technique was derived on the basis of the anatomical outcome of the repair and also the postoperative scarring. The concepts of cleft lip repair have evolved from straight line repairs to a variety of techniques using various cutbacks, triangles, z-plasties and other faps.

The techniques for cleft lip can be broadly classifed into:


We will discuss certain techniques to explain the evolution from a historical point of view. The rotation-advancement technique with its modifcations will be discussed later in this chapter.

### **72.2 Embryology**

#### **72.2.1 Development of the External Face**

The face is derived from two sources: the frontonasal process that covers the forebrain (neural crest origin) and the tissues of frst pharyngeal arch (mixed mesoderm and neural crest origin). These tissues surround the oropharyngeal membrane. From the frontonasal process, two medial nasal processes and lateral nasal processes arise [3]. The frst pharyngeal arch gives

© The Association of Oral and Maxillofacial Surgeons of India 2021 1593

Department of Maxillofacial Surgery and the Smile Train, CHL Hospital, Indore, India

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_72

rise to a pair of mandibular processes and a pair of maxillary processes from which palatal processes arise [3]. The maxillary prominences continue to grow medially, compressing the medial nasal prominences towards the midline, subsequently meeting the lateral nasal processes and then the lower part of the medial nasal processes (Figs. 72.1, 77.1). This lower part is known as the globular or premaxillary process. The components derived from various parts are given in Table 72.1.

Abnormalities throughout this complicated developmental process occur in the most severe congenital forms if they develop early in facial embryogenesis (4–8 weeks) to the relatively minor problems developing later (8–12 weeks). Cleft lip varies from a notch in lips red border to extending into the foor of nostril and the alveolar ridge. It may be unilateral or bilateral (Fig. 72.2). Some other forms of facial clefts have also been described in a pictorial form as a result of failure of fusion of the same processes but in a different trajectory and various permutations and combinations (Fig. 72.3).


**Table 72.1** Components of face derived from various prominences


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**Fig. 72.1** (**a**–**d**) Development of the face. (**a**) Lateral nasal and medial nasal swellings that surround the nasal placodes appear on the frontonasal process (**b**) Paired maxillary processes grow medially, compressing

the medial nasal prominences towards the midline. (**c**) Medial nasal processes fuse with each other, lateral nasal processes and the maxillary processes. (**d**) Complete development of the nose and upper lip

**Fig. 72.2** Relation of embryological derivative to the anatomical and clinical description of cleft lip

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**Fig. 72.3** Embryology of various facial clefts

3. Median cleft lip—a very rare condition. Occurs due to the partial or complete failure of fusion of the two medial nasal prominences to form the intermaxillary segment. It is the characteristic feature of Mohr's syndrome.

#### **72.2.2 Embryology of Cleft and its Surgical Implications**

1. Mesodermal Migration: There are various theories to describe how a cleft occurs. These theories explain that cleft rises as a result of failure of fusion of the fve processes. These processes are formed as a result of mesodermal migration resulting in heaping under the ectodermal layer. Insuffcient or late migration of mesoderm leads to partial or total cleft as a result of epithelial breakdown.

Mesoderm gives rise to the fbromuscular layer of the lip. The importance of mesodermal migration carries in itself an important principle of cleft repair, i.e. muscle approximation. The author's technique presented later in this chapter describes this step as an important step in functional cleft repair. Also the mesoderm has chondrogenic potential which explains the accompanying defcit in the development of nasal capsule [4].

2. Vascular Supply: The philtrum and premaxilla derive their blood supply from the posterior septal artery and terminal branches of the ethmoidal artery (Fig. 72.4). Knowledge of this embryological vascular supply is important while designing the incision on the prolabium in a bilateral cleft lip repair. As the prolabium derives its blood supply solely from the frontonasal process, no back cuts are given during dissection of prolabial fap (Fig. 72.4). This is discussed again in surgical technique.


**Fig. 72.4** (**a**, **b**) As the philtrum and premaxilla are derived from the frontonasal process, their blood supply is from the posterior septal artery and terminal branches of the ethmoidal artery (**a**). As the prola-

bium derives its blood supply solely from the frontonasal process, no back cuts are given during dissection of prolabial fap (**b**)

#### **72.2.3 Prenatal Diagnosis in Cleft Lip**

Cleft lip can be diagnosed in the intrauterine stage with the help of routine ultrasound scanning at different intervals of gestation. The prenatal diagnosis is usually established during the second and third trimester [6]. Recent data suggests that during the 11–13 gestational weeks, a midsagittal view of the fetal head, face and brain, in addition to certain measurable abnormalities, such as a smaller palatino-maxillary diameter, can make grounds for an underlying CLP. 3D sonography can construct a computerized volumetric rendering of the foetus, similar to 3D CT volumetric reconstructions. Detection rates of up to 75% have been described by specialist maternal-fetal medicine [MFM] physicians and radiologists. Thus, prenatal counselling continues to be important with evolving diagnostic procedures. Although there is currently no intrauterine treatment of cleft lip and palate, research has indicated that both mother and child beneft from early diagnosis and counselling. Prenatal counselling has positive psychological implications on the parents of a child with cleft as they are better prepared and motivated for treatment.

#### **72.3 Surgical Anatomy**

Anatomy of the cleft lip patient includes two major components: the lip and the nose. Both the structures vary greatly in a unilateral and bilateral cleft lip deformity and are discussed individually here.

The upper lip is attached above to the nose and blends laterally into the cheek, curving into the lower lip at the commissures. It is formed of muscles and glands covered superfcially with skin and lined internally with mucous membrane. These layers are tightly adherent to the muscles and are sealed along the free margin (Box 72.1).

#### **Box 72.1 Components of an Upper Lip** Normal upper lip anatomy


#### **72.3.1 Surface Anatomy**

The following anatomical surface components of the upper lip are to be kept in mind when assessing a patient with cleft lip (Fig. 72.5). Anatomical equal repositioning of these features is essential for an aesthetic and functional outcome (Box 72.2).

#### **Box 72.2 Anatomic Landmarks**

*Philtral columns*: They are paired bilateral vertical lip bulges created by the dermal insertion of orbicularis oris fbres into the skin of the upper lip.

*Philtral dimple*: It's a concavity between the philtral columns created by relative defciency of muscle fbres.

*White roll*: The white roll is a prominent ridge just above cutaneous-vermillion border. It appears very distinct and white/light in colour due to refection of light off the skin. This is due to insertion of pars maginalis of orbicularis muscle and absence of hair in this region.

*Vermillion*: It's the red mucosal portion of lip divided into dry (keratinized) and wet (nonkeratinized) mucosa.

*Red line*: It's the junction between wet and dry vermillion mucosa.

*Cupid's bow*: A curvature of central white roll, formed by the two lateral peaks as the philtral columns extend inferiorly.

*Tubercle*: Vermillion fullness at central inferior apex of Cupid's bow.

In the normal lip, the columella is a central straight column reaching up to the nasal tip. At its base the columella blends into the nostril sill in front of the nasal foors laterally towards the alar bases. The arches of the alae are symmetrical with equal bulges of the alar cartilages. The eversion of the upper lip places it slightly out in front of the lower lip at the mucocutaneous junction of the upper lip. There is a continuous 1–2 mm rounded roll from commissure to commissure which tops the vermilion and picks up white light it coincides in its curves with the peaks of the Cupid's bow of the vermilion which has central tubercle fanked by, each arch of the bow. The abundance of eleidin in the epithelial cell layers increases the translucency, and the numerous rich capillaries of the papillae create the red colour of this area [5].

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**Fig. 72.5** Surface landmarks of a normal lip and nose

#### **72.3.2 Muscles**

The *orbicularis oris* consists of numerous layers of muscle fbres surrounding the rima oris traversing in different directions. It is partly derived from muscle fbres of the other facial muscles which are inserted into the lips and partly fbres of its own inserted into the skin near the midline. The main fbres of the lips are oblique and pass from the skin to the mucous membrane, throughout the lip thickness. In the upper lip, these fbres group into two bands bilaterally, lateral and medial [total of four bands]: the *lateral band* originating from the alveolus of the lateral incisor tooth and the *medial band* connecting the upper lip to the septum of the nose. The area between the two medial bands forms the *philtrum*, below the septum of the nose. The additional fbres for the lower lip arise on either side of the midline lateral to the mentalis and merge with the other muscles at the commissure [7].

Orbicularis oris derives from eight muscle components with their origins in the modiolus at each angle of the mouth. Orbicularis fbres of one side end by decussating in the median line with fbres from the opposite side. The orbicularis is composed of four pars peripheralis extending from the rima oris on the right and left side. Intimately associated with the pars peripheralis is the pars marginalis with its two right and left components lying in a plane superfcial to the pars peripheralis and confned to the area beneath the vermillion. Pars marginalis is responsible for fne movement (speech) and pars peripheralis for gross movement of the lips (Fig. 72.6a−c). In the presence of cleft, the orbicularis oris muscle fbres do not decussate transversely across the midline but tend to go parallel to the cleft edges towards the base of the nose with their integrity divided. In addition, the transverse nasalis muscle, levator labii superioris and depressor septi do not insert and are prolapsed laterally. They often contract abnormally which has a ripple effect of the lip and the nose. Muscles make the most of their advantage exerting unnatural lateral lifting and distortion of the lip elements in both incomplete and complete clefts. They play a role in displacement of alar base to the side of cleft and the nasal septum on non-cleft healthy side.

#### **72.3.3 Vascular Supply**

The major vascular supply to the lip and nose area is derived from the facial artery, branch of the external carotid artery. Other additional sources are from the ophthalmic and the infraorbital arteries. The facial artery gives off inferior and superior labial branches which arise near the corner of the mouth and course as the coronary vessels beneath the free border of the lips deep to the muscle and close to the mucous membrane. The right and left labial arteries freely anastomose to form a circle surrounding the oral aperture. The facial artery then proceeds upwards along the nasolabial fold and gives off the lateral nasal branch and then becomes the angular artery proceeding up to anastomose with the dorsal nasal branch of the ophthalmic artery. The posterior septal artery arising from the sphenopalatine artery in the roof of the nasal cavity courses down the vomerine groove to the incisive foramen anastomosing with the major palatine and ascending septal branches of the superior labial arteries (Fig. 72.7a, b).

Near the inferior lateral attachment of the ala, the lateral nasal artery divides to run one branch along the lower border and another along the superior margin of the lower lateral cartilage. These branches anastomose in the midline with the terminal branches of the anterior ethmoidal artery. It enters the nose and passes along the undersurface of the nasal bone continuing distally over the upper lateral cartilages to the tip of the nose. It joins the lateral nasal branches to continue into the columella anastomosing with the ascending septal branches of the superior labial artery [5].

Vascular anatomy in a cleft lip has been described pictographically in Fig. 72.8. There is an interruption in the usual arcade in the upper lip in unilateral clefts. However, there is suffcient blood supply to both lip elements and the nose to ensure adequate healing.

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**Fig. 72.6** (**a**–**c)** Concentric band of orbicularis oris forming oral sphincter. Upper and lower fbres arise from each modiolus and decussate in the midline. Superfcial fbres upper lip criss-cross at midline to attach to the dermis of the overlying skin at the philtrum. Deeper fbres attach to the anterior nasal spine [left]. Note the abnormal attachments in unilateral and bilateral clefts [middle and right]

**Fig. 72.7** (**a**, **b**) Vascular anatomy of a complete lip (**a**) and a unilateral cleft lip (**b**)

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#### **72.3.4 Nerve Supply**

The sensory nerve supply to the involved areas of the lips and nose comes from branches of the ffth cranial nerve, trigeminal nerve surfacing through the infraorbital foramen as the infraorbital nerve and through the mental foramen as the mental nerve The motor nerve supply to the muscles of the lips and nose comes from the seventh or facial nerve through its zygomatic, buccal and mandibular branches.

#### **72.3.5 Anatomy of the Unilateral Cleft Lip**

A thorough knowledge of the normal lip anatomy can help us understand the abnormal anatomy in cleft. Displacement of muscle insertions and deformation and functional hypotrophy leading to paucity of tissues result in a distorted anatomy of labial clefts (Fig. 72.9). The following are the characteristics of the cleft lip and nose deformity (Table 72.2):

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**Fig. 72.8** Embryological basis of vascular anatomy in unilateral and bilateral cleft lip

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**Fig. 72.9** Presentation of a unilateral cleft lip. Note the abnormal anatomy of the lip and nose compared to the non-cleft side

**Table 72.2** Comparison of normal and cleft anatomy



Matching of the philtral columns of both sides is central to a successful lip repair. The philtral columns are the paired elevated soft tissue structures of the face which make an important aesthetic subunit. Various surgical manoeuvres have been used to achieve symmetry of the philtral columns. The surgical design of rotationadvancement technique is also based on making the philtral columns of the same height.


#### **72.3.5.1 Nose**

1. Platform: The base, i.e. the premaxilla, is projected and rotated outwards, whereas the lateral maxillary segment is retropositioned. Consequently, there is nasal asymmetry at the base.


### **72.3.6 Anatomy of the Bilateral Cleft**

The following are the salient anatomical features of a bilateral cleft:


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**Fig. 72.10** Presentation of a bilateral cleft lip

#### **72.4 Classifcation and Presentations of Cleft**

As we discussed in embryology, insuffcient or late migration of mesoderm leads to epithelial breakdown resulting in a cleft. Thus, a cleft lip presents in various forms, and the management differs slightly for all forms of cleft. The basic classifcation is based on the side of presentation, i.e. left and right and complete and incomplete (Figs. 72.11 and 72.12). The incomplete cleft lip can be further classifed into various types (Box 72.3).

#### **Box 72.3 Presentation of Incomplete Clefts**

Incomplete clefts can be further divided on the basis of extent of involvement of the mucosa, skin and nasal foor.


Similarly, bilateral cleft lip can be divided into complete and incomplete clefts. Complete clefts can be further divided on the basis of status of the premaxilla. The premaxilla can be severely, moderately or mildly protruded. However, this is a clinical classifcation and helps in deciding treatment of a bilateral cleft lip.

#### **72.4.1 Classifcation**

Throughout history, many surgeons have attempted to classify cleft lip and palate in their own ways. Classifcations made have been on three bases: laterality, severity and morphology of the cleft. At the least any classifcation system should be able to specify the laterality, extent and severity of

**Fig. 72.11** Basic classifcation of cleft lip

lip with mucosal notch not extending into the skin. (**a**) Incomplete cleft lip with mucosal and skin notching. (**b**) Incomplete cleft lip involving the mucosa and skin extending upwards but not up to the nasal foor. (**c**) Incomplete cleft lip with Simonart's band

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the labial cleft and the palatal cleft necessary for treatment planning or outcome assessment (Tables 72.3 and 72.4).

Apart from the above-mentioned classifcations, there are various reports of individual classifcations by many international and Indian surgeons based on their experience and perspective. An ideal classifcation should be simple, clear and universally acceptable for purpose of communication and documentation.

#### **72.5 Treatment of Cleft Lip**

#### **72.5.1 Timing of Intervention**

Cleft lip repair constitutes the frst surgical step in cleft lip and palate. Each cleft protocol team advocates different timings for lip reconstruction, with slight variations from the neonatal period to 6 months and later. Timing of intervention can be broadly categorised based on chronological age of the cleft patient or based on certain dental age milestones and status of dentition (Tables 72.5 and 72.6). There are a number of protocols adopted by various centres around the world. Proponents of traditional repair at the chronological age of 10–12 weeks argue that it poses a decreased risk of anaesthesia-related complications and provides improved aesthetic outcomes and positive psychological assurance to the parents. Surgery was traditionally delayed for several weeks based on the "rule of tens", i.e. infant weighing a minimum of 10 pounds, having a haemoglobin level of 10 g/mL and reaching an age of 10 weeks. This rule was based on the fact that the musculature of the lip is more evolved by this age and thus allows for proper reconstruction [23]. Another important milestone is the neck holding capacity of the baby. It is generally present at 3–4 months of age. It is prudent to wait till this milestone is achieved. This is crucial in cautious transfer of the infant as he/she is transferred to the operating room, recovery or intensive care unit and is handled by various healthcare personnel.

#### **72.5.2 Basic Treatment Algorithm**

We have devised a basic treatment algorithm for unilateral and bilateral cleft lip repair that we follow at our centre. Due to lack of awareness, prenatal and postnatal counselling and the social taboo, many patients in India do not report at the correct age for surgery. As a result, the treatment methods have been modifed based on the age of presentation of the cleft patient to provide the optimal outcome (Figs. 72.13 and 72.14).

#### **72.5.3 Presurgical Nasoalveolar Moulding**

Wider, extensive clefts and bilateral clefts are associated with signifcant deformities of nasolabial complex, presenting a greater surgical challenge in approximating anatomic struc-


72 Cleft Lip

**Table 72.3**

(continued)




**Table 72.5** Timing of intervention based on chronological age


**Table 72.6** Timing of intervention based on status of dentition


tures, thus obtaining an optimum functional and aesthetic result. The basic goal of any surgical technique is to restore normal anatomy and function. Thus in such cases, where it is diffcult to achieve goals of primary repair due to wide discrepancies, presurgical maxillofacial orthopaedic appliances mould the nasolabial structures through specifcally directed forces, thus reducing the deformity before surgery for an easy repair.

Currently, presurgical nasal alveolar moulding (PNAM) is a widely used orthopaedic technique for presurgical cleft deformity correction [23, 24]. PNAM theory is based on the theory that increased hyaluronic acid content is present in the infant cartilage, which makes the cartilaginous structure more pliable and plastic. By the age of 3 months, the cartilage becomes more rigid with less plasticity. PNAM can signifcantly improve the nasal symmetry, by elongating the columella, bolstering the alae, narrowing the cleft and restoring the alveolar arch form, thus demonstrating favourable immediate and long-term outcomes.

PNAM is based on the principles of negative sculpting and passive moulding of the alveolus, lip and nasal tissues. An initial impression is obtained, and custom-made plates are fabricated. A series of modifcations are made to the surface of the appliances with the addition and deletion of materials in certain areas. This process is called negative sculpting [25]. The purpose of this is achieving approximation and symmetry of the two maxillary alveolar segments and addressing the nasal deformity by moulding the cartilage in anatomical position [26, 27] (Fig. 72.15). The process should be explained to the parents; insertion of the appliance should be carefully taught and made to practice. Parents should be explained the importance of this exercise through videos and photos of previous patients.

**Impression Making** A heavy-bodied polyvinyl siloxane impression material should be used for the frst impression. The infant is held in prone position to keep the tongue forward and to allow any material or saliva to drain out of the oral cavity and prevent aspiration. This should be done in a hospital setting to manage any airway emergency in the presence of an anaesthetist available if needed. Once impression is made, the mouth should be examined for any residual material.

**Device Fabrication** The moulding plate is made with clear methyl methacrylate lined with a soft denture material on the dental stone model. The borders should be trimmed and smoothened to prevent any ulceration. The oral surface should be smooth and polished with good retention and no extensions into the cleft area.

**Insertion and Moulding** The moulding plate is to be worn full-time by the patient. It should be removed for cleaning and routine hygiene practices to prevent infection and check for any ulceration. Suckling should be checked with the plate in position and to check gagging. The plate is secured to the

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cheek bilaterally using orthodontic elastics going to the opposite side and secured with surgical tapes. The elastic loop extends from the retention arm approximately in a 40–45 degree angle, thus pulling the anterior fange of the plate posterosuperior vector for activation. 2 ounces of traction force is given by stretching the elastic to twice its original. The surgical tape is applied to a layer of wound dressing material like micropore tape and not the skin directly. The tape is to be changed once a day. The tape should be applied to the noncleft side frst and then pulled over to the cleft side. Weekly follow-ups should be made to evaluate the moulding plate for retention and changes in the alveolar segments.

**Moulding Plate Modifcation** Selective grinding of acrylic material is done from the region into which the alveolar segments are to move. At the same time, soft denture lining material is selectively added to the plate to direct the alveolar segments to the midline, as desired. In a patient with bilateral cleft, the premaxilla is retracted and derotated, to bring to a normal maxillary arch alignment. An ideal surgical result may be obtained when 1–2 mm gap remains between alveolar segments.

**Nasal Stent** When the maxillary alveolar segment approximation has been achieved, the nasal moulding should begin. The nasal stent is added to the existing moulding plate in the form of a stainless steel wire projecting out of the plate outwards going into the nose like a "swan neck". A small wire loop can be made on which a bilobed intranasal acrylic component is made with a layer of soft denture liner. Nasal stent is placed 3–4 mm inside the ala and gently lifted towards dome until slight blanching is noted. **Fig. 72.15** PNAM treatment in a case of bilateral lip. (**a** and **b**) Pre- and postoperative PNAM. Note the changes in the nasal tip, alar cartilages and position of the premaxilla. (**c** and **d**) PNAM device with the nasal stent and lip taping

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Blanching of the nasal tip as the baby suckles activates the appliance. Lip taping is continued after the nasal stent appliance is added.

In a follow-up study over 6–9 years, Bennum et al. observed that patients treated with PNAM within 15 days after birth maintained satisfactory nasal symmetry [28]. Ezzat et al. compared 12 unilateral cleft lip and palate patients with PNAM treatment and found narrowing of the alveolar cleft, increased posterior width of the dental arch, uprighting of the columella and improved nasal symmetry [29]. Yang et al. reported similar results from 45 unilateral complete cleft lip and palate patients [30]. In a large multicentre study sample, Ross argued that orthopaedic correction of the premaxilla failed to stimulate maxillary growth and thus was not necessary [31].

The authors conducted a study to evaluate the nasolabial aesthetics on two-dimensional photographs at 6 months post cheiloplasty. Cupid's bow, vermilion symmetry, vermilion notching, premaxillary show at rest, scar aesthetics, columella height and bialar width were all signifcantly better in the PNAM group [32].

#### **72.5.4 Protocols**

There is no universal protocol for management of cleft lip, and there is a striking diversity of clinical practice. There is a paucity of higher-level evidence (i.e. systematic reviews and randomized controlled trials) on cleft lip and palate. There have been few RCTs comparing individual treatment steps. The Eurocleft study showed that among the 201 European centres, 194 different treatment protocols existed for unilateral clefts [33]. Listed below are some standard protocols followed worldwide.


Discussion of each protocol is beyond the scope of this chapter. However, we have tried to compare and discuss in detail few protocols for a comprehensive understanding of cleft lip and palate repair

The basic protocols of cleft lip repair can also be classifed as follows:


*Primary Cleft Lip Repair Only:* This protocol of early lip repair at 3–4 months of age following the rule of tens is followed popularly at various centres. The author's centre also follows the same protocol. The timing of intervention has been discussed previously in the chapter.

*Primary lip and anterior palate repair:* was proposed by Abyholm in Oslo protocol [37]. In the frst operation, cleft

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**Fig. 72.16** Cleft lip and anterior palate repair: Veau's vomer fap (Veau. 1931). An incision was made on the medial side of the cleft along the border line between oral and nasal mucosae or in bilateral clefts, along the free edge of the vomer. A mucoperiosteal fap is raised from the vomer and turned across the cleft. The lateral edge of the cleft is incised, and the palatal mucoperiosteum is elevated, allowing the vomer fap to be put under the mucoperiosteum and fxed with mattress sutures. In the alveolar area, and in continuity with the vomer fap plasty, the nasal mucoperiosteum is mobilised on both sides and joined across the cleft to complete the nasal foor anterior to the vomer fap. Towards the oral cavity, the raw surfaces of the vomer and of the fap are left uncovered

lip repair using Millard technique with simultaneous anterior hard palate closure using a single layer vomer fap. The mean age for frst surgery was 3.3 months. The soft palate was closed at a mean age of 17.2 months (Fig. 72.16).

*Primary lip and soft palate repair:* It is a well-established early palatal closure which causes maxillary hypoplasia. Because of this reason, many surgeons used to perform palate repair in two stages, i.e. soft palate frst followed by hard palate. At the time of introduction of this protocol, the soft palate was repaired along with the lip at around 4–6 months of age, and the hard palate was repaired at the age of 10–12 years. This was later reduced to 4–5 years.

*Complete Lip and Palate Repair:* one-stage simultaneous repair of the entire cleft is a simple and economic treatment of complete unilateral cleft lip and palate [43]. The concept of one-stage repair was frst introduced in 1958, when Farina (1958) described the surgical technique. A decreased risk associated with general anaesthesia, better healing, lower incidence of fstulae and reduced hospitalization costs has been the rationale for performing such repair. This repair performed in children above 10 months of age has been claimed by surgeons with extremely good results without any complications. Overall, the cleft teams from Brussels, Belgium; Konya and Zonguldak, Turkey; and Warsaw, Poland, found that their protocols employing one-stage closure of UCLP produced favourable morphological results [36, 37, 44, 45].

### **72.6 Unilateral Cleft Lip Repair**

#### **72.6.1 Techniques of Cleft Lip Repair**

The evolution of cleft repair was bound to happen mainly due to the nature of the aesthetics that had to consider the anatomical parameters, namely:


Broadly over the period of cleft history, lip repair can be divided into three basic types depending on the design of fap used (Fig. 72.17). These are straight line repairs (Box 72.4), geometric fap repairs (Box 72.5) and rotation-advancement fap.

**Fig. 72.17** Basic techniques of lip repair

#### **Box 72.4 Straight Line Repairs**


#### **Box 72.5 Geometric Flap Repairs**


#### **Millard's Rotation-Advancement Flap.**

*Ralph Millard (1957)* [2] revolutionized the cleft repair technique with most of its principles applicable and widely used in current day practice. His innovation was in designing the incisions without disrupting the aesthetic subunits. The cut as you go technique was simplifed further by understanding the anatomy of the lip. He realized that two thirds of the Cupid's bow, complete with tubercle, white roll of the mucocutaneous junction, one column and the dimple of the philtrum, were all present in the non-cleft side but askew and thus had to be rotated down to normal position [60].

#### **72.6.1.1 Basic Components of Millard's Repair**  (Video 72.1)

#### **Labelling of the Flaps**

A—Non-cleft side (with Cupid's bow and dimple—rotation). In Millard's original description, the incision for the rotation fap begins at the peak of the Cupid's bow [cleft side], marked along the cleft edge up to the junction with the columella, and curves under the base, crossing the midline, but doesn't cross the contralateral philtral column. Millard later added a back cut at the end of the incision, to allow for adequate rotation of the medial lip element and less tension on the repair [61, 62].

B—Cleft side (advancement).

The incision on the lateral lip element of cleft forms the advancement fap. It is made along the cleft edge, extending up to the nasal foor. This incision should match the length of the incision on the medial side of the cleft.

C—A small triangular fap attached to the columella from the non-cleft side left after the incision.

#### **72.6.1.2 Points Marked: The Following Points are Marked in a Classic Millard's Technique** (Fig. 72.18a, b)


The vertical distance from the alar base on the normal side 4 to the height of the non-cleft peak of the bow 2 gives the distance that must be matched ultimately on the cleft side from its alar base 10 to its peak 8 (usually around 10 mm).


Despite being seemingly complicated, a simple exercise of carrying out the points over an illustration of complete cleft lip shall allow the reader to completely understand the simplicity of the description (Fig. 72.19). Complete surgical technique of Millard's cleft lip repair with the author's modifcation is discussed later in this chapter.

Once the markings are made, the rotation and advancement faps are designed. The basic aim is to achieve symmetry of the philtral columns. This can be achieved by the following methods in a Millard's repair:

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**Fig. 72.18** (**a**, **b)** Basic design of Millard's technique

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**Fig. 72.19** (**a**, **b)** Marking of incisions


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**Fig. 72.20** (**a**–**c)** Mohler's modifcation of Millard's technique

#### **72.6.1.3 Modifcations to Millard's Technique**

In the original Millard's technique, the advancement fap often disrupts the upper third of the cleft side philtral column. Also, in wider clefts the advancement fap results in an unaesthetic scar around the alar base. This led to a series of modifcations to the conventional Millard's rotational advancement technique:

#### **External Scar Placement**

1. *Mohler (1987)* [64]: The medial lip rotation incision was modifed to extend onto the columella. The back cut was added which was confned to the columella. The C fap is used to fll the defect created by rotating the medial lip element at the base of the columella. Thus it is used for lengthening the shortened columella (Fig. 72.20).


In Noordhoff's words the essential features of this technique are as follows:


**Fig. 72.22** (**a**, **b)** Cutting's modifcation


The following modifcations have been made in muscle repair:

(a) *Cutting* [67]: Interposition orbicularis muscle repair.


### **72.6.2 Step-by-Step Technique of Unilateral Cleft Lip Repair: Author's Technique**  (Figs. 72.23, 72.24, 72.25, 72.26, 72.27, 72.28, 72.29, 72.30, 72.31, 72.32, 72.33 and 72.34)

#### Lip Repair:

The authors have presented their technique of lip repair in a stepwise manner.

The following steps have been described:

• Markings: The most important principle of cleft lip repair is to identify the normal and abnormal structures. This includes the length of the philtral columns and the width of wet and dry mucosa. All the soft tissues should be kept in mind while designing the fap. No soft tissue should be discarded or considered redundant.

*Non-Cleft Side.*

Deepest point on cupid's bow, peak on non-cleft side and normal philtral column. (To make the philtral column prominent, one may use a two-pronged nasal hook to pull and retract the columella.)

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**Fig. 72.23** (**a**) Mark the highest point on the Cupid's bow (cleft side), and also notice the philtral dimple. (**b**) Mark the future philtral column, and continue it up to the columella without cutting across the columella

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**Fig. 72.24** From the peak of Cupid's bow on the cleft side, mark the incision on the dry mucosa till the junction of wet and dry mucosa ©Association of Oral and Maxillofacial Surgeons of India


**Fig. 72.25** *Marking of C fap*: A triangular fap between the mucosa and the future philtral column

the cleft side philtral column. The back cut should be made after the muscle closure.


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**Fig. 72.26** M fap: The mucosal element on the non-cleft segment after raising the C fap becomes the M fap and is raised to expose the underlying muscle

and mucosa junction down to the mucosa to keep enough mucosa for nasal layer closure (Fig. 72.25).


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**Fig. 72.27** On the side of the cleft, mark the point B. From the B point, extend the incision along the mucocutaneous junction till point D. From point D, marking goes into the nose to separate the nasal mucosa and the skin [D1]

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#### **Fig. 72.28** Marking of L fap

*Cleft Side:*

• On the side of the cleft, mark the point B. First identify the white roll, and look for the point where the white roll starts to diminish; that is the exact point to join the Cupid's bow. Drop an imaginary line from this point to the junction of dry and wet mucosa. The maximum mucosal width is present at this point.

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**Fig. 72.29** Incision starts from the deepest point of the Cupid's bow till the columella base. The plane of dissection is just above the muscle


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**Fig. 72.30** Nasal layers are now sutured from both the cleft and noncleft sides and sutured using a 4.0 Vicryl


correspond to fnal anatomy, and the skin should be passively seated over the muscle layer. The suturing is completed using 4.0 Vicryl, and the knots are cut fush to prevent any extrusion of sutures on the skin surface (Fig. 72.32).


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**Fig. 72.31** Suturing of the oral mucosa

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**Fig. 72.32** Muscle suturing

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**Fig. 72.33** (**a**) Skin suturing. (**b**) Note the matching of the white roll

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**Fig. 72.34** Dry mucosa suturing

used here is 5.0 Vicryl Rapide or 6.0 Vicryl Rapide (Fig. 72.33b).


### **72.7 Bilateral Lip Repair**

James Barrett Brown said "Bilateral clefts are twice as hard as unilateral clefts, and the results are less than half as good" [69]. Bilateral cleft lip repair can be one-stage or two-stage. Proponents of one-stage repair stress on creating a symmetric, balanced lip. This is indicated in cases of complete or incomplete symmetric bilateral clefts or where the premaxilla is within the arch. Two-stage repair is indicated in the presence of a small prolabium, an asymmetric cleft or a protruded premaxilla. Proponents of two-stage repair advocate this technique for conversion of a bilateral into unilateral cleft, to encourage the growth of prolabium and to avoid excessive lip tension. In earlier techniques of bilateral lip repair, excision of the prolabium was made mistakenly assuming it to be a displaced columella. This was because surgeons failed to recognize the potential of the prolabium to grow in width and height when attached to the dynamic lateral lip elements.

*Principles of Bilateral Cleft Lip Repair:* Certain key points and landmarks need to be kept in mind while considering a bilateral cleft lip repair. The following principles of bilateral cleft lip repair should be adhered to:


#### **72.7.1 Techniques of Bilateral Cleft Lip Repair**  (Video 72.2)

#### **72.7.1.1 Straight Line Repair**

Bardach used a straight line repair. The prolabium was used for the entire central portion of the lip. This caused a problem in case of a short prolabium or a protruded premaxilla [71]. Salyer also used a straight line repair. In his repair, no tissue is discarded, the entire prolabium is lengthened and philtral and skin faps are used for vestibular lining [72].

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**Fig. 72.35** (**a**–**e**) Millard's technique of bilateral lip repair

#### **72.7.1.2 Millard's Repair**

Millard's repair allowed rotation of the Cupid's bow with the gap flled from skin advanced from the lateral element [73]. It allowed complete elevation of the prolabium and suturing of the orbicularis across the premaxilla. In addition, Millard created lateral segments of the prolabium as "forked faps". These faps were banked to add columellar height at a later stage, thus addressing the vertical height defciency, and it also corrected the wide alar bases (Fig. 72.35a−e). The key elements of bilateral lip repair are given in Box 72.6.

#### **72.7.1.3 Mulliken's Repair**

Mulliken designed a narrow prolabial fap with slightly concave sides; 2; 2.5 mm at base and 3.5–4 mm between Cupid s bow peak. The surgical stratagem is symmetrical labial

#### **Box 72.6 Key Elements of Bilateral Lip Repair**


repair and synchronous anatomic positioning of the alar cartilages with sculpturing/draping of the nasal soft tissues. It consists of following elements:


#### **72.7.2 Bilateral Lip Repair: Author's Technique**

Markings: Fig. 72.36 shows the marking of the prolabial fap and the lateral faps.

• Once all incisions are designed, the lip is infltrated with 1:100.000 epinephrine. We can start with either the prolabium or lateral faps. Grab the lip between fngers for better control during incision and bloodless feld.


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**Fig. 72.36** Markings for bilateral lip repair

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**Fig. 72.38** Dissection of the lateral faps

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**Fig. 72.37** (**a**) Marking of the prolabium fap and lateral fap. (**b**) The prolabium fap dissected


#### *Release and repositioning of the following structures from their abnormal attachment:*


## *Suturing*

(a) Nasal Floor


(d) Vermillion Repair

• The midportion of the vermilion is reconstructed by bringing lateral vermilion faps below the philtrum fap (Fig. 72.40).

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**Fig. 72.39** Lateral faps sutured beneath the prolabium. Muscle sutured to create the continuity

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**Fig. 72.40** Position of the prolabium to create the future philtral column

(e) Skin


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**Fig. 72.41** Skin suturing done

#### **72.8 Primary Chielorhinoplasty**

A variety of options exists to address the nasal deformity with cleft lip. These include preoperative nasoalveolar moulding, overcorrection of the nostril width and alar cartilage at the time of lip repair and postoperative use of nasal conformers. Primary treatment of the nose at the time of lip repair has become popular, in order to gain early restoration of the symmetry by repositioning the alar cartilage and lengthening the columella. However, relapse is frequent due to the elastic deformed alar cartilage. Various theories and opinions have been popularized regarding correction of the septum, to either straighten the septum or leave for later correction. A study done by Mancini et al. involves three-dimensional analysis of unilateral cleft lip and palate patients treated with PNAM and primary rhinoplasty, which demonstrated signifcant improvements in nasal projection, columellar length, nasal symmetry and nasal width [74].

#### **72.9 Postoperative Wound Care and Outcome Assessment**

Postoperative wound care is extremely important in determining the results of lip repair and is often a factor resulting in the need of a lip revision.


#### **72.9.1 Outcomes**

Improper surgical technique and tissue dissection can lead to certain undesirable outcomes. Other factors such as wide deformities, severely displaced premaxilla, inadequate postoperative care, poor healing and infection can also lead to aesthetic results. Understanding the process and severity of the outcome helps in addressing the problem in secondary lip repair or lip scar revisions. The outcomes can be divided into the following types:


#### **72.10 Indications for Lip Revision**

Scarred fbrous tissues with poor vascularity always make secondary surgery more challenging. Dissection and reapproximation of surgical landmarks are diffcult in such cases. The basic surgical principles that should be followed are identifcation and preservation of all the vital anatomic structures.

The basic indications for a lip revision surgery are:

	- The scar is not in line with the natural philtral column.
	- The lip length is short.
	- There is a mucosal notching.
	- There is a white roll to Cupid's bow mismatch.
	- There is a nasolabial fstula.
	- There is a wide philtral column.
	- Mucosal notching.
	- Whistling defect.
	- No sulcus depth.

#### **72.11 Conclusion**

In our course of learning of cleft, we often understand embryology, anatomy and the surgical technique as separate concepts. In this chapter, we have tried to integrate them and tried to explain the rationale behind the surgical steps. Embryological basis of normal anatomy and then of cleft is pivotal to understand the arrangements of muscles, the vascular supply and thus the basis of incisions. We have described our surgical technique of cleft lip repair with longterm follow-ups. In the congenital deformity of cleft where there is paucity and deformation of tissues, preserving the tissues during surgery is one of the important principles of lip repair.

#### **72.12 Case Scenarios**

Figures 72.42, 72.43, 72.44, 72.45 and 72.46 represent cases of operated unilateral and bilateral cleft lip with long-term follow-ups.

Figures 72.47, 72.48, 72.49 and 72.50 represents cases of lip revisions with follow-ups.

**Disclosure:** Authors have no fnancial conficts to disclose.

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**Fig. 72.42** (**a**, **b**) Pre operative (**a**) and postoperative (**b**) Photograph of repair of unilateral cleft lip using author's technique of lip repair [7-year follow-up]

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©Association of Oral and Maxillofacial Surgeons of India

case of operated bilateral cleft lip

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**Fig. 72.47** (**a**, **b**) A case of mucosal notching in an adult lip (**a**) Postoperative image after a 2-year follow-up (**b**)

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**Fig. 72.48** (**a**, **b**) A case of operated unilateral cleft lip with mucosal notching and vertical scar contracture (**a**) Postoperative image after lip revision (**b**)

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**Fig. 72.49** (**a**, **b**) An operated case of bilateral cleft lip before (**a**) and after (**b**) lip revision

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**Fig. 72.50** (**a**, **b**) A case of an operated bilateral cleft lip with protruding premaxilla and a wide lip (**a**) Postoperative image (**b**) after lip revision and premaxillary repositioning

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Cleft Palate**

P. V. Narayanan and H. S. Adenwalla

#### **73.1 Introduction**

It was Kilner who said, "Ask not for a spatula and torch to check your cleft palate repair, but listen to your patient speak." By this obvious but profound statement, he drew the cleft surgeons' attention to the fact that gone are the days of breakdowns and fstulae and that if your child does not speak well, your operation is a failure, for such a child would be out of the mainstream of life forever. In spite of the advances in technique and execution, experienced cleft surgeons all over the world still struggle to obtain perfect speech in a large percentage of cases.

In view of the obvious diffculties of intraoral surgery, it is not surprising that cleft lips were repaired way before anyone tried to repair a cleft palate. Credit for the frst successful repair of a cleft palate goes to Le Monnier, a French dentist from Roven. Le Monnier in 1766 cauterized to freshen the cleft edges and sutured them successfully [1].

Cleft surgery then passed through a stormy period of uncertainty in the hands of giants like Ferdinand von Graefe [2], Roux, Dupuytren [3], Dieffenbach [4], and Warren [5]. Mucosal faps were used, and even lateral osteotomies were tried to move the hard palate medially. In 1859, almost a hundred years after the frst hard palate was repaired, von Langenbeck [6] emphasized the need to raise mucoperiosteal bipedicled faps to repair a palate. Langenbeck procedure was a fundamental breakthrough, and with this major advance, breakdowns of the palate were reduced. In its wake

P. V. Narayanan (\*)

Consultant Plastic Surgeon, Jubilee Mission Medical College and Research Institute, Thrissur, Kerala, India

H. S. Adenwalla

refnements followed. In 1931, Victor Veau [7] parted from the bipedicled fap to single pedicled faps based on the greater palatine vessels. Veau stressed the importance of repairing the nasal lining of the palate and the need to lengthen it.

In 1937, Kilner [8] working in Oxford and Wardill [9] working in Newcastle on Tyne independently used a four fap procedure for the complete cleft palate.

The weakness of this procedure was a high fstula rate at the junction of the four faps. In the 1940s, Dorrance [10], Cronin [11], and others used various faps to lengthen the palate. In 1966 Millard [12] introduced his island faps based on the greater palatine arteries to lengthen the nasal lining. Ravin Thatte [13] went a step further and took two island faps one for lining and one for cover and used a tongue fap on the denuded hard palate. All these procedures had their day but were short lived in popularity. However, special mention must be made of the buccal myomucosal fap originally called the cheek fap by Padgett [14]. This fap was revived 30 years later by Murari Mukherjee [15] of Calcutta. He changed the direction of the fap. Recently Ian Jackson has introduced muscle into this mucosal fap to make it more robust, and he calls it a myomucosal fap. He uses it in all his palates to lengthen the nasal lining by 1.5 cm and believes that as a result he achieves better speech. Robert Mann [16] does a Furlow's and coves the residual raw areas with two buccal faps. His rationale is that there is defciency of tissue in the palate and therefore, on frst plastic surgical principles, bring in tissue from outside. This may become the philosophy of the future.

#### **73.2 Embryology and Anatomy** (Figs. 72.1 and 77.1)

#### **73.2.1 Embryology**

The primary palate is derived from the intermaxillary segment derived from the frontonasal and medial nasal

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_73) contains supplementary material, which is available to authorized users.

Department of Plastic Surgery, Burns and the Charles Pinto Centre for Cleft Lip, Palate and Craniofacial Anomalies, Jubilee Mission Medical College and Research Institute, Thrissur, Kerala, India

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_73

P. V. Narayanan and H. S. Adenwalla

prominences. The main part of the defnitive palate is formed by two shelf-like outgrowths from the maxillary prominences. These outgrowths, the *palatine shelves,* appear in the sixth week of development and are directed obliquely downward on each side of the tongue (Fig. 73.1a and b).

In the seventh week, however, the palatine shelves ascend to attain a horizontal position above the tongue and fuse, forming the *secondary palate* (Fig. 73.2a and b). Anteriorly, the shelves fuse with the triangular primary palate, and the *incisive foramen* is the midline landmark between the primary and secondary palates. At the same time as the palatine shelves fuse, the nasal septum grows down and joins with the cephalic aspect of the newly formed palate (Fig. 73.3a and b).

The secondary palate lies posterior to the incisive foramen and consists of the bony hard palate anteriorly and the soft palate posteriorly, terminating at the uvula. The hard palate consists of the palatine bony shelves on either side, attached to the vomer in the midline. The soft palate consists of a sandwich of muscles enveloped by oral and nasal mucosa.

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**Fig. 73.2** (**a**, **b**) Embryology of palate—secondary palate

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**Fig. 73.3** (**a**, **b**) Embryology of palate—completion of palate

#### **73.2.2 Muscles**

The muscles of the soft palate include intrinsic muscle, i.e., musculus uvulae, and the insertions of several extrinsic muscles. Apart from this, large amount of.glandular material is present in the anterior inferior portion of the velum and an anterior aponeurosis. Extrinsic muscles of the velum include the tensor veli palatine, levator veli palatini, palatopharyngeus, palatoglossus, and fbers of the superior constrictor. Pharyngeal muscles usually described as having functional role in velopharyngeal movement include the superior constrictor and the salpingopharyngeus (Fig. 73.4).

Following is a tabular summary for the muscles of palate and their abnormal anatomy in a cleft palate (Table 73.1).

From functional standpoint, it is apparent that the levator veli palatini muscle is the principal and quite possibly the only muscle to function for elevation of the velum in speech. The differences between the normal and the cleft arrangement of the muscles of velopharyngeal closure occur because the muscles extending toward the central line of the soft palate cannot attach themselves in the midline of the velum so they insert at some substitute points. These points prevent the muscles from becoming fully functional, and therefore their development is retarded. With the preservation of normal origins, the atypical insertions and hypoplasia of the muscles are the main pathological features in the cleft palate. The abnormal insertions of levators in clefts illustrate that the function of these muscles in cleft palate is almost opposite to that in normal one. While the muscles of both sides normally join in the raphe to form a sling lifting the palate upward, in cleft palate each muscle pulls its own half of the soft palate in an entirely different direction, i.e., superolaterally, causing further widening of the cleft.

#### **73.2.3 Vascular Supply** (Fig. 73.5a and b)

The internal maxillary artery gives off the descending palatine artery, which in turn gives off several branches to the tonsils and soft palate. It then passes through the posterior palatine foramen, just above the periosteum, and proceeds forward close to the alveolar margin on each side as the greater major palatine artery to the incisive fossa. At that point it sends terminal branch through the incisive foramen to anastomose with the terminal branch of the sphenopalatine artery. The vascular supply of importance is discussed under two headings, anterior and posterior palate.

#### **73.2.3.1 Vascular Supply of the Anterior Palate/ Premaxilla**

The blood supply to the anterior alveolar process of the maxilla comes from the arterial complex composed of the major palatine, anterior and superior alveolar, and branches of the sphenopalatine artery. The posterior septal artery arises from the sphenopalatine artery in the roof of the nasal cavity and courses down the groove of the vomer to the incisive foramen. In the complete bilateral cleft lip and palate, the union of the superior labial arteries is lacking; thus they do not contribute to the blood supply of the philtrum. Also the anastomosis of the posterior septal artery with the major palatine artery is absent. Therefore premaxilla and philtrum must derive their blood supply from the posterior septal artery and to some degree from the lateral and terminal branches of the anterior ethmoid vessels which pass through the columella. There is usually one well-developed vessel on either side of the premaxilla in the region where the incisive foramen should have been. Each of these vessels moves anteriorly and inferiorly into

Orifice of tube Tensor Palatopharyngeus (circular) Tensor (vertical) Tensor (horizontal) Palatopharyngeus (longitudinal) Palatopharyngeus (circular) Salpingopharyngeus Buccopharyngeus Levator (cut) Bilateral cleft lip Bilateral cleft alveolus Bilateral cleft palate **Fig. 73.4** Muscles of the palate demonstrated in a complete cleft of the lip, palate and alveolus (bilateral)

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#### **Table 73.1** (continued)


the philtrum and forms an arcuate anastomosis across the midline in the inferior part of the philtrum.

#### **73.2.3.2 Vascular Supply of Posterior Palate**

The greater palatine artery supplies the oral surface of the hard palate and gives off a few fne branches which perforate the horizontal plate of the maxilla to supply the nasal mucosa. It also sends twigs to the gingiva and the palatoglossal arch. The lesser palatine artery supplies the anterior half of the oral surface of the soft palate. A branch of the facial artery, the ascending palatine artery, is the largest vessel entering the soft palate. It ascends on the lateral side of the superior constrictor muscle to turn downward and forward into the soft palate, between the tensor and levator palati giving small branches to these muscles. Twigs from the tonsillar and ascending pharyngeal arteries also reach the soft palate. In the secondary palate, the existence or absence of cleft makes little difference to the vascular pattern. The palatal mucoperios-

**Fig. 73.5** (**a**, **b**) Vascular supply of the palate

teum is detached from its bony base in the palatal pedicle fap, and as a result the recurrent bony branches are severed. These branches result in bleeding from their cut stumps at the bony surface. This may be judged insignifcant at the time of surgery; however, after the fap is repositioned, should bleeding continue, blood may pool beneath the repositioned fap [17].

#### **73.3 Classifcation and Presentations of Cleft Palate**

Many of the historical and contemporary classifcations have been discussed in brief in the Chap. 72 on cleft lip. However, Veau's classifcation for palate is the most practical and therefore is mentioned again here.

Submucous cleft palate exhibits at least one of Calnan's three criteria [17]:


#### **Table 73.2** Veau's classifcation of cleft palate


Victor Veau (1931) has classifed cleft palates into four groups [7] (Table 73.2)

Clefts of the palate that are less extensive in magnitude include the submucous cleft palate and the occult submucous in cleft palate.

Sommerlad has devised a grading system for the submucous cleft palate with three points for each of the above criteria [18]. A lesser score in this system naturally denotes more trivial clefting. However, paradoxically a lower score refects a poorer prognosis for speech according to this study. An occult submucous cleft does not exhibit any of Calnan's criteria but shows a trough-like depression on the superior surface of the soft palate as seen in nasoendoscopy. Croft believed that in these patients, the musculus uvulae is absent. It is suspected when a child with a normal palate speaks with nasal emission.

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**Fig. 73.6** (**a**, **b**) Picture of child with Pierre Robin Sequence

#### **73.4 Clinical Evaluation of the Cleft Palate Patient**

#### **73.4.1 General Examination**

A routine per-oral examination of the neonate reveals the cleft of the palate with or without cleft lip. The extent of clefting is noted. General examination is mandatory as it is important to identify syndromic patients. These are more common in isolated cleft palate patients [19]. Pierre Robin sequence is a fairly common presentation with micrognathia or retrognathia (Fig. 73.6 and b). As the bony abnormalities are believed to be the cause of the non-descent of the tongue in utero leading to the clefting of the palate, this is now believed to be a sequence and not a syndrome. Syndromic patients include Treacher Collins syndrome, Goldenhar syndrome, etc.

#### **73.4.2 Clinical Assessment of the Cleft**

The frst clinical visit usually happens soon after birth. The extent cleft is assessed, i.e., the length of the palate and the width of the cleft. Randall has classifed cleft palate on the basis of length into four types [20]. Clefts may be partial or complete. A partial cleft of the secondary palate is confned to the soft palate (Fig. 73.7).

A complete cleft includes both the soft and the hard palate up to the incisive foramen (Fig. 73.8). In patients with bilateral cleft lips, the associated cleft palate usually presents with a central vomer and clefting on either side of the vomer (Fig. 73.9).

A pediatric assessment is made for other anomalies, weight of the baby is noted, and feeding instructions are given during this visit. A squeezable feeding bottle is usually advisable to overcome child's diffculties in sucking. The child is fed with the head held slightly higher. Parents are counselled about the need for immunization. They are also explained about the need for surgery and are shown results of the procedure on similar patients. It is very important to allay their anxiety as they are very often crestfallen on seeing the deformity in their baby. Subsequent visits, possibly at monthly intervals, aim to assess the growth and development of the baby. Associated cardiac or other anomalies if present need investigation.

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**Fig. 73.7** A child with partial cleft palate

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**Fig. 73.8** A child with complete cleft palate

### **73.4.3 Imaging and Other Investigations**

Routine imaging is not generally practiced in the evaluation of cleft palate patients. Syndromic patients require other investigations as part of the various manifestations of their syndromes. For instance, children with velocardiofacial syndrome may require echocardiogram in view of the associated cardiac anomalies. Children with delayed development, microcephaly, etc. will require neurological assessment and will usually need an MRI of the brain. Rarely a child may have a meningoencephalocele presenting behind the palate. MRI has been used to evaluate submucous clefts with a view to help in the planning of the management. If it can be shown that there is not adequate muscle continuity across the midline, an early decision can be taken to operate on the child at the usual time of cleft palate repair. On the other hand, if there is good muscle across the midline, these repairs can be

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**Fig. 73.9** A child with bilateral cleft palate

justifably delayed until the development of speech. MRI has also been used to assess the Eustachian tube function. Hearing assessment should be mandatory in all cleft palate patients.

### **73.5 Preoperative Factors** (Box 73.1)

#### **Box 73.1 Preoperative Considerations**


The dilemma regarding the timing of repair is between earlier repair with better prognosis for speech, but worse prognosis for maxillary growth, and late repair which is exactly the opposite. Most surgeons today agree that the cleft palate is to be operated close to 1 year. Some prefer 9 months, where others wait for up to a year and 4 months. At our center we have been operating on these children at about 11 months of age. The Oslo school of surgeons [21, 22] devised a protocol of operating on the lip with the soft palate in the frst stage and operating on the hard palate much later. In some centers, the palate has been repaired frst at initial presentation, and the cleft lip is repaired, subsequently, in view of the fact the children may not be brought back for treatment of the palate once the lip is repaired [23].

2. Airway.

Airway management is important at the time of birth in cleft palate patients, as most of isolated cleft palates may be associated with a smaller airway at birth. This may be due to associated sequence or syndromes, such Pierre Robin sequence or Treacher Collins syndrome. Such patients might require emergency tracheostomy or tongue lip adhesion to secure airway. Defnitive management for mandibular advancement and cleft palate repair can be undertaken at a later stage.

3. Feeding.

As mentioned already, the parents are counselled about feeding practices during the frst visit itself. Expressed breast milk is to be preferred. Special feeding bottles like the Haberman feeding bottle are used when the common methods like the use of simple squeezable bottles are not effective. As a cleft child swallows air along with the milk, frequent burping is essential to avoid regurgitation of feeds.

4. Anesthesia.

The operation is performed under general anesthesia with an endotracheal tube. RAE tubes are preferred for cleft palate patients. Previously, Oxford red rubber tubes were used. These were well adapted to the needs of the cleft children but often caused laryngeal edema presumably due to the latex in the tubes. At our center we have given up the use of these otherwise very useful tubes.

Preoperatively, the child must be assessed by a good pediatrician and also by a senior anesthetist. Respiratory infections are common in these children and must be treated if signifcant. X-ray of the chest is usually done to rule out heart or lung anomalies. Cardiology clearance is required when there are suspected cardiac anomalies. We have come across one case with a congenital absence of the lung.

The anesthetist should be experienced in pediatric anesthesia. In patients with Pierre Robin sequence or other anomalies like shoulder or spinal anomalies, diffcult intubation is to be anticipated, and appropriate equipment such as intubating endoscopes, etc. should be at hand, and the anesthetist must be familiar with its use.

### **73.6 Principles and Methods of Repair**

There are various surgical techniques described in literature. The techniques have been mentioned (Box 73.2), with the author's surgical technique described in detail (Figs. 73.23, 73.24, 73.25, 73.26, 73.27, 73.28, 73.29, 73.30, and 73.31).


#### *The basic principles of cleft palate repair are*:


#### **Box 73.2 Methods of Cleft Palate Repair** Methods of repair


### **73.7 Surgical Technique** (Figs. 73.12, 73.13, 73.14, 73.15, 73.16, 73.17, 73.18, 73.19, 73.20, 73.21, 73.22, 73.23, 73.24, 73.25, 73.26, 73.27, and 73.28)

Once intubated, the child is placed with the neck extended for adequate visualization of the palate. A pillow under the shoulder helps in this positioning. A suitable mouth gag is used. We use the Dott's gag (Fig. 73.12) with the Kilner suture carrier. A popular gag used widely is the Dingman's gag.

*Infltration:* A solution of lignocaine with 1 in 200,000 adrenaline is infltrated under the mucoperiostem of the hard

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**Fig. 73.11** Wardill's four fap palate repair. (**a**) are the anterior faps while (**b**) form the posterior faps that are closed in a "V to Y" fashion to gain length for the "push-back"

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**Fig. 73.12** Dott's gag

palate and above the nasal mucosa in the soft palate. A dental syringe with a short-beveled needle is very useful for this purpose.

*Surgical procedure:* At our center, we use the two longfap technique popularized in India by Charles Pinto and the world over by Bardach (Fig. 73.13). The technique was originally used by Veau. The cleft edges are pared (Fig. 73.14).

The lateral incision is made from the maxillary tuberosity area toward the retromolar area posteriorly. The pterygoid hamulus is dissected, fractured, and detached (Fig. 73.15a and b).

This aids in mobilization of the nasal layer subsequently. However, there are many surgeons nowadays

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**Fig. 73.13** Pinto Wardill (Bardach) two long-fap procedure. Classical method of raising two faps detached at the anterior pedicled on the greater palatine artery

who do not believe in fracturing the hamulus. It has, however, been shown in different studies that fracture of the hamulus does not cause any deleterious effects on hearing [26].

The lateral incision is then carried anteriorly and the oral mucoperiosteal fap is lifted off till the medial edge of the hard palate using Kilner's palate elevators (Fig. 73.16a and b).

An incision is then made on the medial border of the hard palate, and the fap is also divided anteriorly taking care to secure the end of the greater palatine vessels. The oral fap is then raised till the posterior border of the hard palate. Laterally, the greater palatine vessel is identifed and skeletonized, after incising the cone of periosteum which binds the vessel behind it (Fig. 73.17a, b, c and d).

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**Fig. 73.14** Pared cleft edges

After the hamulus is fractured, the medial pterygoid plate is denuded of any soft tissue attachments (Fig. 73.18).

Similarly, the posterior border of the hard palate is also cleared of muscular attachments (Fig. 73.19a and b).

A Cumine Scaler is introduced over the bare medial pterygoid plate and then turned anteriorly to separate the nasal layer from the hard palate in one clean sweep. This dissection is then completed on a deeper plane with a Wallace's fnisher (Fig. 73.20a and b).

This practice of separating the nasal layer from behind forward was originally introduced by Kilner [8] but has somehow not been followed widely. It is much easier than the alternative method of separating the nasal layer from the hard palate starting anteriorly. Very often this results in tearing of the nasal layer.

Similar dissection is performed on the other side also, raising a long oral mucoperiosteal fap. The vomer fap is raised (Fig. 73.21) and used when accessible and necessary.

Rarely, the vomer is receding and cannot be used. In a bilateral cleft lip patient, the vomer is in the midline, and a central incision on the vomer is made to raise two mucoperiosteal faps, one on each side, to be sutured to the corresponding side in nasal layer of the hard palate.

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**Fig.73.15** (**a**, **b**) Fracture of the pterygoid hamulus

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**Fig. 73.16** (**a, b**) Elevation of the oral fap with Kilner's elevator

#### **73.7.1 Dissection of the Soft Palate**

The early techniques of cleft palate repair only detached all false attachments of muscles from the posterior border of the hard palate (Fig. 73.22).

Surgeons like Braithwaite [27] and Kriens [28] emphasized the importance of the dissection and retroposition of the levator veli palati muscle. This was popularized by Sommerlad [29] and Tambewekar in India.

Infltration of lignocaine with 1:200,000 adrenaline is made between the nasal mucosa and the muscle (Fig. 73.23).

A transverse incision is made on the aponeurotic layer just beyond the hard palate (Fig. 73.24).

Then the muscle is dissected off the underlying mucosa leaving behind enough tissue on the nasal layer, to avoid its tearing during suturing. Also, a narrow layer of muscle is retained along the cleft edges to hold the sutures. The muscle is dissected till just short of the uvula. The muscle contains the levator veli palati mostly. However, it also contains other muscles like the palatopharyngeus ("muscle of Veau") (Fig. 73.25).

The extent of dissection of the muscle on the soft palate varies. The authors [30] only separate it from the nasal layer. Others like Sommerlad [29] also separate it off the oral layer. However, if there is any suspicion of injury to the greater palatine vessels during dissection, then the levator muscle should not be dissected free of the oral mucosa.

#### **73.7.2 Suturing**

Suturing commences on the nasal layer from anteriorly, proceeding backward. The sutures are not tied but held on the Kilner suture carrier.

#### **73.7.2.1 Uvula**

The last suture on the nasal layer is a mattress suture (Fig. 73.26) [30].

Next, an apical mattress suture is placed on the tip of the uvula, and this suture is left long and held on an artery forceps, thus turning the uvula over, providing access to the nasopharyngeal aspect of the uvula. Two or three simple sutures are placed between the mattress suture and the apical stitch (Fig. 73.27a).

Then two or three mattress sutures are placed on the oral aspect of the uvula (Fig. 73.27b).

The nasal layer sutures are then tied from behind forward.

"A" suture: this is the suture placed at the junction of the hard and soft palate. It goes through the nasal mucosa and later crisscrosses into the oral mucosa, resembling the letter A, but is like the fgure of "8" when tied.

Anterior sutures are also tied but retained long.

Suturing of the oral layers then proceeds from behind forward, with every suture picking up a bite on the nasal layer to obliterate dead space. The dissected levator mus-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 73.17** (**a, b**) Incising the Periosteal cone to free the greater palatine artery. (**c**, **d**) Hooking out the greater palatine vessels (the vessel is pulled out like a bird pulls a worm out of the ground). This reduces the tension on the faps on suturing

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 73.18** Medial pterygoid plate dissection

cle is also included in these oral sutures. Some surgeons close the levator muscle as a separate layer. The anterior sutures are then brought through the oral layer also, helping in anchoring the oral layer. In the absence of the anchoring, the oral layer may sag postoperatively causing a "fallen palate."

Laterally the raw areas are sutured with interrupted sutures without tension. This helps in hemostasis (Fig. 73.28).

Previously, this area used to be packed with different materials, but there was often bleeding from the areas on removal of the pack postoperatively.

Buccal pad of fat harvested through a stab incision on the buccal aspect bilaterally has also been used to fll large lateral raw areas.

#### **73.8 Complications:** (Box 73.3)

#### **Box 73.3 Complications**

*Immediate complications.*


#### **73.8.1 Early Complications**

#### **Hemorrhage**

This is often from the apices of the long faps, from the cut ends of the greater palatine vessels. Arterial bleeding points need to be ligated or cauterized using diathermy. Small venous bleeding areas can be controlled by the use of pressure with fngers or by the use of crushed ice or topical hemostatic agents like tranexamic acid.

#### **Respiratory Obstruction**

This may be from tongue fall and can be avoided by use of a tongue stitch at the time of palate repair. The tongue stitch has to be placed well posteriorly and must include a good bulk of the tongue tissue to avoid the sutures from tearing through.

When a wide cleft palate is closed, the child may have diffculty in learning to breathe adequately through the nose. Laryngeal edema due to endotracheal tube-related trauma may present with a hoarse cry and, in severe cases, chest retraction. Early detection is important, and this can be reversed by intravenous steroids and nebulization.

#### **Breakdown of the Repair**

It may result in fstulas or complete breakdown of the repair. The most common cause of these, especially at the junctional area, is suturing of the cleft edges under tension due to inadequate mobilization.

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**Fig. 73.19** (**a**, **b**) Dissection of the posterior end of the hard palate

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**Fig. 73.20** (**a**, **b**) Completion of nasal layer dissection with Wallace's Finisher

**Fig. 73.21** Posterior incision on the vomer

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**Fig. 73.22** Complete dissection of the oral and nasal layers

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**Fig. 73.23** Infltration of adrenaline beneath the palatine aponeurosis

**Fig. 73.24** Incision of the palatine aponeurosis

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**Fig. 73.25** Complete dissection and retroposition of the levator palati muscle

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**Fig. 73.26** Mattress suture at the base of uvula

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**Fig. 73.27** (**a**) Apical suture on uvula turned over and posterior sutures placed. (**b**) Completion of uvular reconstruction

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**Fig. 73.28** Completed suturing of the palate and the lateral raw areas

### **73.8.2 Long-Term Complications**

Long-term complications include poor speech. Adequate muscle repair has helped in better speech results. Nonetheless, speech is an enigma that has not been adequately understood and mastered. The variables like width of the cleft, the gap between the uvula and the pharynx, and the adequacy of the muscle repair all have a bearing on the speech results. Despite all the advancements in the repair of the cleft palate, no surgeon can truly claim to achieve perfect speech results in all patients consistently.

### **73.9 Long-Term Results**

The long-term evaluation of cleft palate patients should include the presence or absence of a fstula, the quality of speech, and the growth parameters of the maxilla, i.e., whether there is maxillary hypoplasia.

At present, many centers are able to produce fstula-free palates in a majority of patients. Tension-free closure of the palate and meticulous suturing are the key factors in the prevention of fstulas. A review of literature reveals a huge range in the incidence of fstula after cleft palate repair. The range is from 2.6 to 58%. In between these extremes, many have reported around 10%, some 15 and 23% [31, 32].

The emphasis on good levator veli palatini dissection and repair has led to improved speech results overall. However, one can never perfectly predict the speech outcome, as speech itself is an enigma. Probably as a result of the variation in the presentation, mode of repairs and age at the time of repair, etc., the published literature notes a VPI rate of 5.9–70% [32].

Maxillary growth continues to be a problem. Operations like these of Robert Mann show promise in this direction. Again, owing to variability involved in the type and extent of cleft, the time of repair and the nature of the surgery, the need for maxillary advancement may range from 10 to 40% in non-syndromic cleft patients [32].

#### **73.9.1 Secondary Repair and Revision**

The age old saying that primary surgery is the best chance for the surgeon to obtain optimal results is very apt in the repair of the cleft palate. A badly repaired cleft palate sometimes leaves behind a grossly scared palate with paucity of tissue. Small soft palate fstula can be repaired by freshening of the edge and two-layered closure. Small hard palate fstulas can be repaired by local turn over faps for lining and oral mucoperiosteal faps for the oral layer. Larger ones and those with poor speech will require revision palate repair. When there is gross defciency of tissue, faps like the tongue faps, or temporalis musculocutaneous fap, facial artery muscle mucosal (Famm) fap may be necessary [33, 34].

Secondary palate repair is also required for velopharyngeal incompetence (VPI). A detailed discussion about the management of such incompetence is beyond the scope of this chapter. Diagnosis of VPI is by speech assessment, nasoendoscopy, or videofuoroscopy. Once a diagnosis is made, treatment modalities will include redo palate repair, sphincter pharyngoplasty, or fap pharyngoplasties, depending on whether it is the palate, lateral wall (palatopharyngeus) or the posterior wall, or a capacious pharynx as seen on investigations.

Subsequent interventions will be required for maxillary hypoplasia when signifcant. This is again out of the scope of this chapter. In brief, anterior maxillary distraction is done if the maxillary advancement required is signifcant and the facial bones are still growing. Some of these do require a LeFort 1 osteotomy later on if there is relapse. When the growth is completed, then a LeFort 1 osteotomy is required when there is signifcant maxillary hypoplasia. When the advancement required is more than in 1 cm, bijaw surgery is needed, with a LeFort 1 advancement in the maxilla and a bilateral sagittal split osteotomy of the mandible.

#### **73.10 Recent Techniques**

The use of the buccal mucosal fap in primary repair was pioneered by Padgett [14] and then used extensively by Murari Mukherjee [15]. Later Ian Jackson incorporated buccinator muscle into the fap and used it on the nasal layer transverse to provide for lengthening of the soft palate.

Furlow's Double Opposing Z plasty described by Furlow [35] is increasingly used both for primary and secondary repair of cleft palates. This illustrated in the figure (Fig. 73.29a, b, c and d). Robert Mann has described the extensive use of the double opposing "Z" plasty with the buccal flaps over the nasal and/or oral layers to avoid lateral incisions and to promote for better bony growth. This is probably the method of the future as it shows promise of good speech and good maxillary growth. However, extensive suturing of the buccal flaps is involved and this is not the optimal surgery for the novice to try. The Mann procedure is for the experienced cleft surgeons [36].

#### **73.11 Case Scenario**

#### **Case 1**

This is a patient with a partial cleft of the secondary palate (Fig. 73.30). The hard palate is intact. The cleft palate was repaired at the age of 11 months using the Veau-Wardill V-to-Y repair and radical muscle dissection in the soft palate. Subsequently the child is undergoing regular follow-up and speech assessment.

#### **Case 2**

This is a child with a complete cleft of the primary and secondary palate on the (Fig. 73.31). The cleft lip was repaired at 6 months of age using the Millard's rotation advancement technique. At 11 months, the cleft palate was repaired using the two long-fap procedure popularized in India by Charles Pinto, the mentor of the senior author, and, worldwide, by Bardach. The child is now being subjected to constant follow-up and speech therapy.

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**Fig. 73.29** (**a**, **b**) Furlow's double opposing "Z" plasty (**a**) incision, (**b**) faps raised and mucosal incisions placed, (**c**) double opposing Z plasty completed and (**d**) oral faps inset

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**Fig. 73.30** Repair of incomplete cleft palate

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**Fig. 73.31** Repair of complete Cleft palate

#### **73.12 Disclosure**

Authors have no fnancial conficts to disclose.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Alveolar Bone Grafting**

**74**

Veerabahu Muthusubramanian and Kalarikkal Mukundan Harish

#### **74.1 Introduction**

Attempts to graft the alveolus started in the early 1900. The rationale for the procedure however has changed over the period. From its use as a procedure for establishing continuity over a defect, it has evolved and made itself indispensable in both cleft-related orthodontics and orthognathic surgery. Over the years, the technique has evolved, and the materials used have also been constantly studied and improved upon. This chapter aims to elaborate on the morphology of the alveolar cleft, its implications on dentition as well as facial skeleton, and the various management strategies and evolving trends.

#### **74.2 Normal Anatomy of Alveolus**

The alveolar process is that part of the jaw that contains the tooth sockets and forms a bridge between the teeth and the basal bones. The alveolar process is present in both the maxilla and the mandible. The status of the alveolar process and its development depends on the status of the teeth; if the teeth are absent or lost in later life, it reduces in size, eventually disappearing completely.

#### **74.2.1 Development of Alveolar Process**  (Figs. 72.1, 73.1, and 77.1)

The alveolar process begins to form in the end of the second month of fetal life. The maxilla and mandible develop a groove-like structure that opens toward the surface of the oral cavity. This groove contains the tooth germs, the dental nerves, and vessels. Gradually, bony septa begin to develop between adjacent tooth germs. Later the primitive mandibular canal is separated from the dental crypts through a horizontal plate of bone. The alveolar process remains fused to the body of the maxilla and mandible, and its formation is completed during tooth eruption.

#### **74.2.2 Structure of Alveolar Process**

There is no distinct boundary between the body of the maxilla or mandible and their corresponding alveolar processes. In conditions where the alveolus is not functionally related to teeth, it may be fused with and partly masked by bone.

Based on function, the alveolar process consists of two parts:

	- (i) The compact bone/cortical plate forming the vestibular and oral plates of the alveolar processes.
	- (ii) The spongy bone between these plates and the alveolar bone proper.

The cortical plates are usually much thinner in the maxilla than in the mandible. They are thickest in the bicuspid and molar region of the mandible especially on the buccal side. In the maxilla, the outer cortical plate is perforated by many small openings through which blood and lymph vessels pass. In the mandible, the cortical bone of the alveolar process is dense and, occasionally, shows small foramina. In the region of the anterior teeth of both jaws, the supporting bone is, usually, very thin. No spongy bone is found here and the cortical plate is fused with the alveolar bone proper.

The interdental and interradicular septa contain the perforating canals of *Zuckerkandl and Hirschfeld*, which house

V. Muthusubramanian (\*) · K. M. Harish

Department of Oral and Maxillofacial Surgery, Ragas Dental College, Uthandi, Chennai, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1655

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_74

the interdental and interradicular arteries, veins, lymph vessels, and nerves. The alveolar bone proper which forms the inner wall of the socket contains many openings which transmit branches of the interalveolar nerves and blood vessels into the periodontal membrane. It is named cribriform plate or lamina dura.

#### **74.2.3 Functions of Alveolar Bone**

The primary functions of the alveolar bone are highlighted in (Box 74.1).

#### **74.3 Alveolar Anatomy in Cleft Patients**

The alveolar cleft is usually represented either by a notch in the alveolus on the labial aspect or as a complete gap between the alveolar segments. In unilateral alveolar clefts, the cleft side of the maxilla (referred to as the lesser segment) is underdeveloped, causing abnormalities of the alveolus, as well as the lip, nose, and palate.

#### **74.3.1 Abnormalities of the Alveolus and Dentition**

The abnormalities of the alveolus and the dentition are projected in (Box 74.2).

#### **74.3.2 Abnormalities of the Lip-nasal Complex**


#### **Box 74.1 Primary Functions of the Alveolar Bone**


#### **Box 74.2 Abnormalities of the Alveolus and the Dentition**


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**Fig. 74.1** Intraoral frontal picture demonstrating clinical features of cleft alveolus (left side). (Refer to Box 74.2 for description of a, b and c)


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 74.2** Basal view picture demonstrating abnormalities of the lip-nasal complex (**a**) mismatch of the lower lateral cartilages and (**b**) widening of the nostril due to lack of support for the cleft side alar base

#### **Box 74.3 Goals of Orthodontics in Alveolar Bone Grafting (ABG)**


### **74.4 Role of the Orthodontist in Patients with Alveolar Cleft** (Box 74.3)

The objective of alveolar bone grafting (ABG) primarily involves restoring the structural and functional integrity of maxillary alveolar arch. This would further facilitate the eruption of the canine or lateral incisor into their respective position in the maxillary alveolar arch. The further employment of orthodontic treatment would help in stabilizing the arches and achieving proper alignment of misaligned teeth, The aim of orthodontics in ABG are highlighted in Box 74.3.

The orthodontist must be involved at all stages of dental development, namely, infancy, primary, mixed dentitions, and the permanent dentition stages.

#### **74.4.1 Infancy**

1. Pre-surgical orthopedics can be done with the use of appliances such as Latham's appliance, etc. It consists of a pin-retained device that is inserted into the palate with acrylic extensions onto the alveolar ridges. Further a screw mechanism is then used to manipulate the segments as desired.


In case of untreated clefts, the maxillary development was found to be normal. Which indicates that early lip repair may affect maxillary growth.


Jackscrew and spring-loaded appliance are some of the orthopedic appliances used. However, the effect of these appliances are still controversial.

#### **74.4.2 Primary Dentition**


#### **74.4.3 Mixed Dentition**


be high in scarring), surgical access to cleft area, and compliance of the patient are factors that determine the selection of appliance.


#### **74.4.4 Permanent Dentition**


#### **74.5 Alveolar Bone Grafting Procedure**

#### **74.5.1 History** [1]

Attempts to graft the alveolus started in the early 1900s. In the beginning, the goal was to prevent collapse of the alveolar ridge. Therefore, it was done during infancy. In 1970, reconstructive surgeons like Boyne [2, 3] stated that the ideal age for grafting the cleft was between 9 and 11 years. This was done to allow eruption of the canine.

#### **74.5.2 Classifcation**

Alveolar bone grafting procedures are classifed into four types based on the age and timing of the procedure:


The advantages and disadvantages of the various methods are highlighted in Table 74.1.

#### **74.5.3 Materials Used in Alveolar Bone Grafting**

A variety of materials have been used in grafting in secondary cleft deformities.

These include autogenous, allogenic, or alloplastic materials.

The success rate differs for each type, but fresh autologous cancellous bone is considered to be superior because it allows cells that are immune-compatible and integrate fully into the maxilla and trigger osteogenesis. In addition, it is the only bone source which possesses all the properties that promote bone formation—osteogenesis, osteo-conduction, and osteo-induction.

#### **74.5.3.1 Bone Grafts**

• Cortical:

Cortical bone refers to the compact outer part of the bone. This is generally less vascular, and so establishment of nutritional supply to cortical cells is a slow pro-


**Table 74.1** Comparison of advantages and disadvantages of different ABG techniques

#### cess. Therefore, this graft generally resorbs and is replaced by invasion of bone cells originating from the recipient site. The rate of metabolic turnover and cortical bone remodeling is much slower than in cancellous bone. Therefore, keeping the tooth-bearing function in mind, cortical grafts may not be feasible for the alveolar process.

• Cancellous:

Cancellous bone refers to the softer trabecular bone that is more vascular. This allows better ingrowth from the recipient site. The formation of new bone starts at the surface of the existing cancellous bone. Cancellous bone theoretically heals by osteogenesis, followed by bone resorption and deposition. This graft is harvested as a particulate form, so it may be diffcult to stabilize it in the recipient site.

• Cortico-cancellous:

A combination of the two produces good results and enables good vascularization to help incorporate bone with surrounding structures. It also adds good mechanical strength.

#### **74.5.3.2 Autogenous Materials**

The following sites are commonly used as sources for autogenous material used in alveolar bone grafting:

#### 1. Cranium [5]


#### 2. Iliac Crest [6]

	- Bone provided is more cortical and is limited compared to the ilium.
	- Damage to the adjacent teeth and mental nerve has been reported.
	- It is used by 4% of surgeons in Europe [7].
	- It has suffcient bone which is quick to harvest.
	- There is minimal scarring, and patient may be mobilized early but is restricted from sports for 3 weeks.
	- In children where the tibia is usually small, there is a possibility of damage to the epiphyseal cartilage.
	- Used by 3% of European and 2% of North American surgeons [8].

#### 5. Rib [9]

	- Bone may also be harvested from the intermedullary canal of the femur, but it carries the risk of high morbidity.

#### **74.5.3.3 Alloplastic Materials**

Alloplastic materials that have been used for ABG include rhBMP-2 (recombinant human bone morphogenetic protein), undecalicifed freeze-dried bone, TEOM (tissueengineered osteogenic material), and bioglass.

#### 1. rhBMP-2

	- This material contains MSC (mesenchymal stem cells), PRP (platelet-rich plasma), human thrombin, and mixed air.
	- Available in a gel form.
	- Claimed rate of success is about 70%.
	- This commercially available material is made up of silicone dioxide, sodium dioxide, calcium oxide, and phosphorus pentoxide.
	- It binds both to the soft tissue and bone.
	- Designed to engender surface reaction, which leads to osseointegration.

### **74.5.3.4 Allogenic Materials**

These materials are comparable to autogenous materials and allow for eruption of teeth while avoiding donor site morbidity. However, they do not have osteogenic potential, which causes delayed graft incorporation.

These materials include:


Most of the abovementioned products involve bone obtained from genetically dissimilar individuals. These allogenic bone particles are subjected to various processes to ensure the allogenic graft material is devoid of any microbial contamination however retaining the organic matrix and the inorganic components. They are available in various particle sizes or as block grafts or can even be milled for specific patients using CAD CAM technology.

#### **Box 74.4 Goals of ABG**


### **74.5.4 Technique for Alveolar Bone Grafting**

The technique of alveolar bone grafting must be performed with the following goals in mind (Box 74.4).

Alveolar bone grafting procedure is performed under general anesthesia. It can be performed comfortably using both naso-tracheal and oro-tracheal intubation. When iliac crest is the chosen donor site, a two-team approach can be followed simultaneously. The surgical sequence for unilateral ABG (Figs. 74.3a–f and 74.4a–f) and bilateral ABG (Fig. 74.5) are detailed below.

Surgery in the oral cavity is begun with infltration of local anesthesia containing adrenaline to assist hemostasis. It has to be borne in mind that the reconstruction of cleft alveolus involves neat and precise development of labial/palatal/ nasal layers and creating of a pocket for placement of graft, as this will ensure creation of structural and functional integrity of the alveolar arch. A fne needle gauge is used to probe the bony edges of the cleft in order to identify the site of the frst incisions (Fig. 74.5b). The initial incision must be made through the mucosa lying over the cleft and must pass down to the bony margins (Fig. 74.3a, b). Try to preserve the soft tissue on the labial and palatal sides. Adequate (and sometimes excess) tissue is usually present within the oronasal fstula, which may be sacrifced after planning for the oral layer closure. In the region of the pyriform aperture, there is no bony margin. Hence, at this site the soft tissue is divided to provide a layer for the superior most extent of the nasal closure. A similar kind of division of the mucosa is necessary on the palatal side too (Fig. 74.3c).

Next, incisions are made around the cervical region of the teeth on the labial aspect of the alveolus. The incisions should extend several teeth posteriorly from the cleft with the exact distance determined by the width of the cleft. A full-thickness mucoperiosteal dissection should be begun to raise a large advancement fap. A similar procedure is carried out on the palate, where incisions are made around the neck of the teeth followed by full-thickness mucoperiosteal dissection. As an alternative oblique sliding faps can also be raised (Fig. 74.3a, b). As these dissections are proceeding,

**Fig. 74.3** (**a**–**f**) (**a** and **b**) Incisions around the cleft margin and for developing oblique sliding faps (dashed lines), (**c**) Palatal faps are developed sharply with scissors. This also separates the nasal mucosa from the palatal tissue. (**d**) Palatal closure. This can be done before or

after the nasal mucosa is closed. (**e**) Depiction of the nasal mucosal fap along with the closure of the oral mucosa. (**f**) Nasal mucosal faps are refected from the bony walls of the cleft. The palatal fap facilitates packing and protects the palatal closure [4]

**Fig. 74.4** (**a**–**f**). (**a**) Nasal faps are approximated with sutures burying the knots when possible. (**b**) The closure of the nasal mucosa and the introduction of the bone graft to the alveolar defect. (**c**) Bone is packed into the defect with a periosteal elevator or orthodontic band pusher. Digital pressure against the palatal fap facilitates packing and protects

the palatal closure [4]. (**d**) Closure of the labial oblique sliding fap. (**e**) Final mucosal closure of the labial and palatal oblique sliding faps. (**f**) A palatal splint placed over the closure area to prevent formation of a hematoma and stabilize the bone graft

**Fig. 74.5** (**a**–**i**) (**a**) A bilateral alveolar cleft palate. (**b**) Needle palpation of the bony edges of the alveolar cleft while injecting local anesthesia. (**c**) The incision line (dashed line). (**d**) Elevation of the nasal mucosa on the left and closure of the nasal mucosa on the right. Placement of

the bone graft. (**e**, **f**) Palatal depiction of the movement of the adjacent mucosa in the oblique sliding fap technique. (**g**) Mucosal closure in a bilateral alveolar cleft. (**h** and **i**) Final closure of the bilateral alveolar cleft repair using an oblique sliding fap technique

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**Fig. 74.5** (continued)

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**Fig. 74.6** Pre-operative intra oral picture demonstrating collapsed maxillary arches with hidden oro-nasal fstula

the periosteal elevator may be carried around the cleft to allow the mucoperiosteum within the fstula to be rotated superiorly. This allows the full extent of the bony cleft to be visualized. Excess tissue within the nasal portion of the cleft

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**Fig. 74.7** Pre-operative intra-oral maxillary arch view of the same patient in Fig. 74.6, providing good visualisation of the oro-nasal fstula

can be trimmed, and then the nasal faps are sutured to provide closure of the nasal foor. This helps in the closure of a persistent oro-nasal fstula (Figs. 74.6, 74.7, and 74.8). It is ideal to evert these faps into the nose and to use inverted

#### 74 Alveolar Bone Grafting

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**Fig. 74.8** Clinical picture demonstrating labial and palatal fap refection and closure of nasal layer

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**Fig. 74.9** Clinical step in which a periosteal elevator is used to defne the alveolar cleft after closure of the nasal layer

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**Fig. 74.10** Creation of a pouch with closure of the labial faps in the alveolar cleft region to facilitate bone grafting

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**Fig. 74.11** Exposure of the iliac crest to harvest bone graft

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 74.12** Cancellous bone graft harvested from iliac crest

sutures so that the knots are on the nasal side. One should mobilize the palatal faps toward the cleft (Fig. 74.8), utilizing releasing incisions if necessary. The palatal faps may be sutured using interrupted sutures (Figs. 74.9 and 74.10).

The harvested bone is then (Figs. 74.11 and 74.12) condensed into a syringe prior to placement and packed tightly into the exposed bony cleft. While placing the bone graft, it is important to establish a normal contour to the pyriform aperture region. The labial faps can be then advanced over the graft. This usually requires the utilization of the periosteal-releasing incisions made perpendicular to the direction of the advancement. A tension-free closure is mandatory for this technique (Fig. 74.13).

The two palatal and two labial faps are then closed, utilizing a suture that simultaneously approximates all four corners. The fnal closure is completed with interrupted sutures closing the labial faps and the interdental releases (Fig. 74.14). Closure is performed in a way that retains the attached gingiva overlying the reconstructed alveolus. Rarely, it may not be possible to obtain adequate advancement of faps which necessitate the use of a cheek fap or a free gingival graft.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 74.13** Grafting of the alveolar cleft using harvested cancellous bone from the iliac crest

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 74.14** Watertight closure of the alveolar cleft after grafting

#### **74.5.5 Postoperative Assessment of Alveolar Bone Grafting**

The success of alveolar bone grafting depends on certain outcomes, which include Box 74.5.

#### **Box 74.5 Factors Determining Success of ABG**


Several scales are used to assess the success based on the above criteria. These scales use periapical, panoramic, or occlusal radiographs. A few of these scales are given below:

#### • *Bergland scale* [12] (Fig 74.15a–d).

This scale is the gold standard of assessment, and success is judged based on the height of the post-graft interdental bone septum. It is assessed after the eruption of permanent canine. Four categories of success are defned, with

Types I and II being satisfactory outcomes and Types III and IV being unsatisfactory:

*Type I*: Interdental septum height is almost normal (<25% of bone resorption).

*Type II*: Interdental septum height is equal to or greater than ¾ of the normal height (bone resorption 25%–50%).

*Type III*: Interdental septum height is less than ¾ of the normal height (bone resorption 50%–75%).

*Type IV*: Bone graft failure; no continuous bony bridge is visible across the cleft (bone resorption ≥75%) (Fig. 74.15).

#### • *Chelsea scale* [14] (Fig 74.16a–f).

This scale evaluates the presence of bone in relation to the teeth adjacent to the cleft. Based on this, six categories have been identifed. Only Types A and C represent satisfactory outcomes.

*Type A*: Bone tissue is present at the cementoenamel junction of the teeth adjacent to the cleft. At least 75% of roots on either side are covered by bone.

*Type B*: Bone tissue is present at the cementoenamel junction of the teeth adjacent to the cleft. At least 25% of roots on either side are covered by bone.

*Type C*: Bone tissue is present and surrounds at least 75% of the roots on either side of the cleft, in an apical direction.

*Type D*: Bone tissue surrounds at least 50% of roots on either side of the cleft, with an apical to coronal direction.

*Type E*: Bone tissue bridge is present in the cleft, except in the apical and coronal directions.

*Type F*: Less than 25% of bone tissue is present around both roots in the apical direction (Fig. 74.16).

#### **Fig. 74.15** (**a**–**d**) Bergland scale [13]

• *Trindade-Suedam scale* [15].

These authors modifed the Bergland scale described above and used alphabets to describe success or failure:

*E* (*Excellent)*: Interdental septum height is normal. *G* (*Good)*: The bony septum is visible, with minimal disability.

*R* (*Regular)*: Bone graft is enough to allow for canine eruption. However, tooth movement is defcient, or a defect that is more than 25% of root length is seen.

*B* (*Bad)*: Defcient bone in the nasal region, which does not permit tooth movement.

*F (Failure):* Bone graft is completely resorbed.

• *Kindelan scale* [16].

This scale compares pre-operative and postoperative occlusal radiographs, to assess the percentage of bone fll. This also considers the eruption of the canine.

Grade 1—Bone fll >75% (Fig. 74.17). Grade 2—Bone Fill 50–75%. Grade 3—Bone fll <50%. Grade 4—Complete absence of bone.

### **74.6 Complications of Alveolar Bone Grafting**

The complications of alveolar bone grafting may be witnessed at the donor as well as the recipient site.

**Fig. 74.16** (**a**–**f**) Chelsea scale [13]. (**a**) bone present at the Amelo-cemental Junction (ACJ) and covering 75% of both the roots, (**b**) bone present at the ACJ covering atleast 25% of both the roots, (**c**) bone covering atleast 75% of both the roots from the apical direction, (**d**) bone covering atleast 50% of the roots from the apical direction, (**e**) bony bridge present across cleft but no bone apically or coronally and (**f**) less than 25% bone cover from the apical direction

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 74.17** Occlusal radiograph after bone graft with a Kindlean score of 1

©Association of Oral and Maxillofacial Surgeons of India

#### **74.6.1 Donor Site Complications**

The site-specifc donor site complications are highlighted in Box 74.6.

#### **74.6.2 Recipient Site Complications**

	- (a) Osteoresorptive cells and an environment suitable for bone resorption—this occurs with deciduous tooth extraction.
	- (b) Excessive tension or trauma after surgery, resulting in exposure and loss of the graft.
	- (c) Overpacking of the graft, causing alveolar notching and graft resorption. (d) Poor oral hygiene.

#### **74.7 Conclusion**

Alveolar bone grafting aims at restoring the functional integrity of the alveolar arch. In addition, they facilitate the eruption of teeth through the grafted bone into their respective positions. The timing of alveolar bone grafting is very crucial and can be effectively assessed by evaluating the thickness of bone covering the crown (of the lateral incisor or of the canine), rather than the degree of root formation of these teeth. The usage of autologous cancellous bone from the iliac crest is the most widely accepted graft in the mixed dentition period. In recent years, bone substitutes have also been used

#### **Box 74.6 Donor Site Complications**

(a) Iliac crest:

	- Risk of inner table penetration.
	- Postoperative chest infection.
	- Pneumothorax.
	- Injury to mental nerve.

because of a tendency toward limited bone harvesting. These allograft or alloplastic sources of bone graft are especially useful in case of defcient donor autogenous bone material or to minimize donor site morbidity or in complicated cases. However, autologous bone is still the ideal choice for alveolar bone grafting, and none of the currently available methods can replace autologous bone completely. The future trend in alveolar bone grafting could be related to the usage of stem cells for bone regeneration; however many long-term clinical trials have to be conducted using stem cells to ensure its wide usage and cost-effectiveness.

**Disclosure** Authors have no fnancial conficts to disclose.

#### **74.8 Case Scenarios**

#### **Case 1** (Fig. 74.18a–f)

An 11-year-old female patient who was treated for unilateral cleft lip and palate on the left side presented with the complaint of leakage of fuid from the nose and escape of air from the oral cavity. She had undergone primary unilateral lip repair when she was 6 months old, and a palatal repair was done when she was 2 years old.

Procedures, which were performed at this stage—fstula closure and alveolar bone grafting.

A sulcular incision along with incision around the fstula was performed both on the labial and palatal side so to enable direct access to the fstula and bony defect. Oral and nasal layers were separated. The nasal layer was initially closed in a watertight manner. Cancellous bone graft was obtained from the iliac crest, and the bone graft was placed into the defect, and watertight closure was obtained.

Future treatment required—pre-surgical orthodontics, orthognathic surgery, post-surgical orthodontics, and rhinoplasty (if required).

#### **Case 2** (Fig. 74.19a–j)

#### **Case Presentation**

A 10-year-old female patient who was diagnosed with unilateral cleft lip and alveolus on the left side (Fig. 74.19a, b) reported to us with a chief complaint of leakage of fuid from the nose. She had previously undergone primary lip repair at 8 months of age. An OPG and IOPA revealed the extent of alveolar cleft (Fig. 74.19c, d). Pre-surgical orthodontic treatment was started to align the teeth and facilitate the eruption of 23 (Fig. 74.19e).

Procedures, which were performed at this stage—fstula closure and alveolar bone grafting.

A sulcular incision was placed around the involved teeth both on labial and palatal sides which exposed the fstula and the alveolar defect. A careful dissection was performed so as to separate the nasal layer and oral layer. The nasal layer was initially closed in a watertight manner. An adequate quantity of cancellous bone graft was harvested from the iliac crest. Thus obtained bone graft was placed into the alveolar defect, and a watertight closure was performed (Fig. 74.19f). The alveolar bone graft was assessed 6 months post-surgery using IOPA (Fig. 74.19g). The orthodontic treatment was completed after facilitating the eruption of canine and achieving leveling and alignment of teeth (Fig. 74.19h, i, j).

Future treatment required—Patient has to be assessed after growth completion, and if required the following treatment will have to be carried out:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 74.18** (**a**–**f**) (**a**) Extraoral frontal picture at rest. (**b**) Extraoral frontal picture at smile. (**c**) Intraoral picture demonstrating fstula. (**d)** Palate post-repair. (**e**) Creation of a pouch in the alveolar cleft region to facilitate bone grafting. (**f**) Grafting of the alveolar cleft using harvested cancellous bone from the iliac crest. (Fig. 74.14 shows Watertight closure of the alveolar cleft case shown in Fig. 74.18, after grafting)

**Fig. 74.19** (**a**–**j**) (**a**) Intraoral frontal picture demonstrating alveolar cleft on the left side of maxilla and associated fstula. (**b**) Intraoral maxillary occlusal picture demonstrating alveolar cleft and fstula. (**c**) OPG demonstrating the alveolar cleft on the left side and the eruptive status of the upper left permanent canine. (**d**) IOPA demonstrating the presence of alveolar cleft between upper left central incisor and upper left canine. (**e**) Intraoral frontal picture. Orthodontic treatment to facilitate tooth alignment and eruption of permanent upper left canine. (**f**) Intraoral picture demonstrating the completion of alveolar bone grafting. (**g**) IOPA demonstrating the uptake of alveolar bone graft in the region of alveolar cleft between upper left central incisor and upper left canine. (**h**) Intraoral frontal picture demonstrating orthodontic treatment. The permanent canine on the left side has been clinically moved to the occlusal plane. (**i**) Intraoral maxillary occlusal photograph postorthodontic treatment demonstrating the eruption and alignment of upper left canine in the alveolar arch. (**j**) Intraoral photograph postorthodontic treatment demonstrating the eruption and alignment of upper left canine in the alveolar arch

**g**

**i**

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 74.19** (continued)

#### **References**


defects – a comparison between Chin and Rib grafts. J Cranio Max Fac Surg. 1990;18:205.


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## **Cleft Maxillary Hypoplasia**

Philip Mathew, Mustafa. K, and Paul Mathai

#### **75.1 Introduction**

Studies of adult patients with unoperated cleft lip and palate (CLP) indicate that the maxilla in the unoperated patient is normally positioned or protruded. There are two major factors contributing to the protruded maxilla. The frst is the absence of normal functional forces that are provided by the perioral muscle and tissue continuity. The tongue pressure pushes the teeth and the alveolus forward while the pressure from the cleft lip and affected perioral tissues is insuffcient to balance this force out. The second factor contributing to the prognathic maxilla is the missing surgical scar [1–3].

Studies comparing unoperated cleft lip cases versus those with cleft lip repair show minimal difference in the growth of the maxilla. Thus, it has been proven that cheiloplasty has little effect on the growth of the maxilla and its dentition. On the other hand, palatal surgery has been identifed as the main cause of inhibition of midface growth. Scar tissue forms across sutural areas as a result of palatoplasty surgery. This scar tissue interferes in the downward and forward translation of the maxilla that plays a major role in normal development. Furthermore, the scar tissue across the palate

**Disclosures**: The authors have no fnancial conficts to disclose

Mustafa. K

causes the constriction of the maxilla leading to a collapsed bite or crossbite [1–3].

Maxillary hypoplasia is a secondary deformity that occurs as a result of cleft lip and palate surgery with a reported incidence of about 9–45% with isolated cleft lip cases having the lowest incidence. The need for surgical correction of the same can be identifed as early as age 10. Factors frequently associated with maxillary hypoplasia are congenitally missing maxillary teeth, revision palatoplasty procedures, pharyngeal faps, and delayed orthodontic care [4–7]. However, recent evidence has suggested that presence of a pharyngeal fap does not affect maxillary growth [8].

#### **75.2 Features of Cleft Maxillary Hypoplasia**

Cleft maxillary hypoplasia presents as a three-dimensional defciency. The degree of defciency increases with the severity of orofacial clefting and affects different anatomical subunits, e.g., dentoalveolar, para-nasal, infra-orbital, and zygomatic regions. The clinical features associated with cleft maxillary hypoplasia are described in Boxes 75.1–75.3 [1–3, 7].

The presence of the cleft alveolus causes the dentoalveolar segment to collapse palatally on the affected side(s) leading to the creation of anterior and posterior crossbites. The failure to perform an alveolar bone grafting and orthodontics during the growing phase increases the severity of the malocclusion [9, 10]. The extent of this abnormal growth of the midface varies from mild to severe and is also affected by genetic endowment, the severity of clefting (extent of orofacial and labio-palatal involvement), timing of surgery, surgeon skills, and the number of primary and revision surgeries performed in the process of re-habilitating the patient. It has not been conclusively proven if any particular palate closure technique or if a staged technique has reduced effects on maxillary growth. It is the author's opinion that techniques that leave a raw area on the palate like pushback palatoplasty are generally associated with greater maxillary regression [1–3, 11–15].

**75**

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_75) contains supplementary material, which is available to authorized users.

P. Mathew (\*)

Head of Department of Oral and Maxillofacial Surgery, Jubilee Mission Medical College and Hospital, Thrissur, Kerala, India

Department of Craniofacial Surgery, Kanachur Institute of Medical Sciences, Mangalore, Karnataka, India

P. Mathai

Senior Resident cum Fellow of Orthognathic Surgery, Department of Oral and Maxillofacial Surgery, Jubilee Mission Medical College and Hospital, Thrissur, Kerala, India

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_75

#### **Box 75.1: Primary Features of Cleft Maxillary Hypoplasia**


#### **Box 75.2: Secondary Residual Deformities in Cleft Lip and Palate Patients**


#### **Box 75.3: Dental Anomalies in Cleft Lip and Palate Patients**


In most cases, photographic and cephalometric analysis reveals that the mandibular plane-cranial base angle is increased leading to a more backwardly placed mandible. Thus, the mandible tends to have a mild retrognathic appearance in spite of having normal dimensions. An anterior open bite is observed if the patient has an underlying tongue thrust habit as well. In certain rare cases, the chin and mandible may also exhibit a degree of skeletal asymmetry [1–3] (Box 75.2).

The need for orthognathic surgery should be based not only on occlusion and jaw relationship but also on facial proportions, midface projection, and complaints of the patient [1–3].

#### **75.3 Objectives of Treatment** (Box 75.4)

#### **Box 75.4: Objectives of Treatment in Cleft Maxillary Hypoplasia**


#### **75.4 Sequencing Treatment in CMH** (Box 75.5)

#### **Box 75.5: Sequencing Treatment in CMH**


#### **75.5 Orthodontics in Cleft Lip and Palate Patients**

Owing to the severity of the condition, period of orthodontics can be prolonged and is carried out in three phases. Sometimes patients with CLP have a limited ability to open their mouth further increasing the diffculty of orthodontic treatment.

*Phase 1 Treatment* It is carried out between 7 and 12 years of age. Maxillary transverse expansion is carried out in cases that present with maxillary constriction. Maxillary protraction may be carried out in cases with signifcant midface regression. This phase also involves monitoring facial growth, space management, monitoring eruption of permanent teeth, and preventing ectopic eruption of permanent teeth [1–3].

In preparation for secondary alveolar bone grafting, extractions of supernumerary teeth and deciduous teeth on either side of the cleft and closure of oronasal fstulae are performed [16]. Box 75.6 outlines the controversy regarding whether maxillary expansion should be performed before or after alveolar bone grafting [17–19].

#### **Box 75.6: Arch expansion, before or after Alveolar Bone Grafting (ABG)**


*Phase 2 (Presurgical phase) Treatment* It is carried out between 12 and 17 years of age. It involves maintaining the previously attained expansion and further expanding the arch in cases of relapse or if no prior expansion was done. In case the skeletal discrepancy is minimal, we can also consider camoufage orthodontics to correct the occlusal discrepancy. Camoufage orthodontics involves correction of crowding and rotations, extraction of teeth that have erupted ectopically and cannot be accommodated, proclination of maxillary incisors, and retraction of mandibular incisors.

In case the skeletal discrepancy is moderate to severe, then we will have to consider surgical correction (distraction osteogenesis or orthognathic surgery) of the deformity. Presurgical fxed orthodontics is started to facilitate the planned skeletal movements and is described in Box 75.7.

#### **Box 75.7: Objectives of Pre-surgical Orthodontics**


In case the lateral incisor is missing, the decision to maintain space for prosthetic rehabilitation or substitute it with the adjacent canine needs to be made during this phase [1–3]. There is also a need to extract the mandibular third molars in case a bilateral sagittal split osteotomy is planned. There is an increased risk for bad splits associated with un-erupted and impacted mandibular third molars in the age group of less than 20 years on account of thinner and immature cortical bone [20].

*Phase 3 (Postsurgical Phase) Treatment* It is performed after surgical correction of the facial deformity (orthognathic surgery or distraction osteogenesis). It involves fne-tuning of the occlusion and maintaining achieved results in the long term through retentive appliances. One may have to consider re-creating dental compensations to accommodate for increased rates of relapse after cleft-orthognathic surgery.

#### **75.6 Considerations Before Surgery**

#### **75.6.1 Timing of Surgery**

Facial growth is normally completed by 16 years of age in females and by 17 years of age in males. It is advisable to perform orthognathic surgery only after skeletal maturity is achieved, in order to increase stability of the surgical results in the long term. In selective cases, orthognathic surgery is performed during growth for psychosocial or functional reasons. However, this has shown unpredictable results because of continued growth of the mandible with relapse rates in the range of 50–70% when operated before 18 years of age [2, 21, 22].

As an alternative, one may consider distraction osteogenesis prior to 17 years of age. A study by Meazzini et al. [23] reported a relapse rate of 26% in the long term when distraction osteogenesis of the maxilla was carried out during the growing phase. A systematic review by Liu et al. [24] reported a relapse rate 12–46% at "point A" and 26–77% for the SNA angle in the long term. Thus, the patient will require additional surgery after skeletal maturity for correction of the residual facial deformity, irrespective of whether distraction osteogenesis or orthognathic surgery was performed.

#### **75.6.2 Status of Alveolar Bone Grafting and Oronasal Fistulae**

Patients with cleft lip and palate usually present with a cleft alveolus. This cleft communicates with the nasal cavity, thus, creating an oronasal fstula. The cleft is also a source of weakness in the maxillary arch and increases the risk of arch collapse, thus, creating dentoalveolar deformities (e.g., crossbites) which make later surgical procedures like orthognathic surgery unstable. Lastly, the permanent teeth that erupt into the cleft will have a poor prognosis due to lack of bony support and inadequate periodontium. Thus, it is of utmost importance to graft the cleft alveolar region, and the benefts associated with it are described in Box 75.8 [9, 25].

#### **Box 75.8: Benefts of Alveolar Bone Grafting**

Reduction of oronasal fstula, creation of continuity of the maxillary alveolar arch, eruption of permanent teeth into the cleft site, elevation of the alar nasal base, and stability for future surgical procedures like orthognathic surgery and rhinoplasty

A prerequisite to a successful alveolar bone grafting is the closure of oronasal fistulae. Small fistulae can be closed at the time of grafting. However, the presence of a large fistula requires a staged reconstruction with the fistula closure initially and alveolar bone grafting later.

It is not rare to see a patient with a complaint of maxillary regression who presents at a later age (17 years and above) with a history of no alveolar bone grafting or failed alveolar bone grafting. If we proceed with a LeFort I osteotomy in this clinical scenario, the diffculty of the surgical procedure increases signifcantly as the maxilla is not a single unit. There are three possible treatment protocols that we can follow:


#### **75.6.3 Velopharyngeal Insufciency (VPI)**

If air or sound is allowed to leak through or resonate in the nasal cavity during the production of the non-nasal sounds (all phonemes except /m/, /n/, and /ng/), speech will be marked by hyper-nasality (nasal twang) and nasal air emission. VPI describes a structural or anatomic defect that prevents closure of the velopharyngeal mechanism during function. It is most commonly observed in patients with an overt cleft palate (unoperated > operated cases) and submucous cleft palate. In operated cleft palate patients, the incidence of VPI can range between 20 and 50% [31]. Chua et al. [32] and Pereira et al. [33] proposed the usage of perceptual speech assessment, acoustic measurement with nasometer, video nasoendoscopy (or video fuoroscopy), and cephalometric analysis for the assessment of preoperative speech and VPI.

When the maxilla is advanced in operated cases of the cleft palate, speech articulation is improved on account of improved lip competency and correction of previous dental malocclusion [34, 35]. There is also an associated increase in the velopharyngeal cavity depth [36]. As compared to the normal palate, the scarred cleft palate has decreased ability to adapt to such changes as it is unable to stretch adequately [37] This leads to an increase in the risk for worsening of preoperative VPI. The effect of maxillary advancement on VPI, especially in cleft palate patients, is still a controversial topic [34, 38].

There are two methods that are commonly used to advance the maxilla as given in Box 75.9.

#### **Box 75.9: Methods Used for Maxillary Advancement**

	- (a) Total maxillary distraction: internal maxillary distraction and rigid external distraction

The theoretical advantage of distraction is that the maxilla is advanced slowly which allows the patient to adapt to the changes in the velopharyngeal dimensions through increased velar muscle activity. Furthermore, distraction can be halted at any point of time that speech begins to deteriorate. Orthognathic surgery, unlike distraction, creates an immediate surgical advancement of the maxilla and does not allow speech to be assessed incrementally or allow for gradual adaption of the palate to the increase in the velopharyngeal cavity depth.

A randomized controlled trial by Chua et al. [32] for moderate maxillary advancement (4–10 mm) in cleft patients demonstrated that distraction osteogenesis had no advantage over orthognathic surgery for the purpose of preventing velopharyngeal incompetence and speech disturbance. Furthermore, no correlation was found between the amount of advancement and speech parameters. However, it should be noted that extreme advancements of the maxilla (greater than 10 mm) were excluded from the study.

A study by McComb et al. [37] helped identify predictors for worsening of VPI in cases of cleft maxillary advancement using conventional orthognathic surgery. Short preoperative soft palate, large postoperative velopharyngeal cavity depth, preoperative perceptual speech assessment, nasometry, and video nasoendoscopy were identifed as clinically signifcant predictors. Preoperative velopharyngeal cavity depth was not considered a satisfactory predictor as changes in the velopharyngeal space did not correspond proportionally to maxillary advancement [39]. Lastly, the span of maxillary advancement (2–16 mm) did not show a signifcant association with the worsening of VPI [37].

Janulewicz et al. [35], Philips et al. [40], Alaluusua [41], Smedberg [42], Seok-Kwun Kim et al. [43], Kelly Schultz et al. [44], and Pereira et al. [33] studied the relation between postoperative worsening of VPI and maxillary advancement using conventional LeFort I osteotomy in cleft patients. They established that preoperative borderline and higher grades of VPI were highly prone to worsening in the postoperative phase. Absent to negligible VPI pre-operatively, carries minimal risk of worsening during the post-operative period. Furthermore, the amount of maxillary advancement and the cleft type did not infuence the degree of worsening of VPI. In the author's opinion, the only confounding factor in the above studies was that some of the patients already had a preoperative pharyngeal fap.

A study by Trindade et al. [45] suggested that deterioration in the VPI after orthognathic surgery was transient and improved over time. Compensatory changes are known to occur in the velopharyngeal region during that time as documented by the study of Yu Wu et al. [36]. The velar length and angle and the velopharyngeal depth all increased. However, velar thickness, posterior pharyngeal wall thickness, and velar motility remained unchanged. During certain phonations, the motion of the posterior pharyngeal wall and the thickness of the Passavant's ridge increased signifcantly. Thus, it is advisable to wait for at least 1 year prior to considering surgical correction for VPI [35].

Poole et al. [46] and James et al. [47] suggested alternative surgical approaches to the routine LeFort I maxillary advancement which involved transecting the palatal mucosa followed by mobilizing the soft palate lying distal to the incision. This was combined with strategically placed vertical incisions in the maxillary buccal mucosa to avoid circulation injury. The advantage of the procedure was that the maxilla could be advanced by large amounts without worsening of speech and VPI as the soft palate did not move anteriorly with the maxilla. The disadvantage of the procedure was that a signifcant portion of the palate was left denuded and was expected to heal secondarily. Though the results were promising, the techniques did not become mainstream.

Anterior maxillary distraction (AMD) is a versatile, stable, and simple technique that can be used to correct the maxillary dentoalveolar regression in the cleft maxilla after the mixed dentition phase (Video 75.1). As the osteotomy is anterior to the junction of the hard and soft palate, the velopharyngeal dimensions and soft palate activity are not affected. Thus, it is considered optimal for the correction of cleft maxillary regression in cases with preoperative moderate to severe VPI. When used in the age group of 10–16 years, there is also an associated posterior movement of the distal maxilla owing to the elasticity of the bone which may also reduce preoperative VPI to a certain extent. An added advantage is that the increased arch length can be used to accommodate un-erupted teeth and correct crowding [48–53].

In case postoperative VPI develops, it is advisable to wait and watch for at least 1 year prior to resorting to surgical correction. During this period, one can try conservative methods like speech therapy and bulb palatal lift prosthesis and minimally invasive methods like autologous fat injections into the soft palate and the posterior pharyngeal wall [31, 54, 55]. If the VPI does not improve to a clinically acceptable level even after a year, then surgical options need to be considered.

In terms of risk of development of postoperative obstructive sleep apnea, Furlow palatoplasty and buccal myomucosal faps have the least adverse effect followed by sphincter pharyngoplasty and fnally pharyngeal fap which has the most adverse effect [56, 57]. Nonetheless, the pharyngeal fap is the most commonly used method, and a recent paper by Dentino et al. [58] demonstrated that the superiorly based pharyngeal fap was highly successful in correcting VPI after cleft maxillary advancement.

#### **75.6.4 Degree of Maxillary Hypoplasia**

The classifcation of cleft maxillary hypoplasia is given in Box 75.10.

#### **Box 75.10: Classifcation of Maxillary Hypoplasia**


The above classifcation of maxillary hypoplasia needs to be combined with the age at which the patient presents for optimal treatment planning. It should be noted that the regression is calculated only on the basis of reverse dental overjet. The presence or severity of para-nasal hollowing is not accounted for in the above classifcation.

#### **75.7 Treatment Plans**

#### **75.7.1 Pearls for Treatment Planning**

• If surgical treatment (distraction osteogenesis or orthognathic surgery) is performed prior to the skeletal maturity, there is a high chance of relapse due to continued skeletal growth. Thus, additional surgery will be required to correct the residual skeletal deformity. Nonetheless, distraction osteogenesis is preferred over orthognathic surgery in the growing patient.


regions. As the mandible is usually unaffected in cleft maxillary hypoplasia, a setback beyond 8 mm leads to a poor aesthetic result and is also associated with higher relapse rates.

	- Determining preoperative speech and VPI status is a must: perceptual speech assessment, acoustic measurement with nasometer, video nasoendoscopy (or video fuoroscopy), and lateral cephalometric analysis.
	- If there is no preoperative VPI, then there is minimal risk for worsening of speech and occurrence of VPI postoperatively.
	- If there is borderline (or greater) VPI preoperatively, then there is a high risk for worsening of VPI postoperatively.
	- Wait for at least 1 year before considering surgical correction of postoperative VPI.

#### **75.7.2 Age Group of 6–11 Years** (Fig. 75.1)

The patient has a mixed dentition during this phase. There are multiple un-erupted dental follicles present that can pose a problem to certain surgical procedures. Alveolar bone grafting is preferably performed during this phase as it is associated with higher success rates [26]. Large oronasal fstulae, if present, need to be closed prior to secondary alveolar bone grafting.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 75.1** Treatment plan for age group 6–11 years

If the child presents with a mild regression, one can choose to wait and watch or proceed with dentofacial orthopedics using a reverse pull headgear to achieve protraction of the maxilla. If the child presents with moderate regression, then one must proceed with reverse pull headgear therapy to achieve some degree of correction.

The usage of reverse facemask therapy requires considerable patient co-operation and works by stimulating growth at the various maxillary suture sites (Fig. 75.2a–c). It is usually combined with a maxillary expansion appliance that helps disrupt the circum-maxillary sutural system and increase the effects of the orthopedic face mask. The general effect produced is that of a downward and forward movement of the maxilla, backward rotation of the mandible, and a net increase in the lower facial height. However, the response varies widely from individual to individual, and long-term stability is also questionable [7, 63–66].

The stability and extent of correction with reverse facemask therapy reduces with increasing severity of labiopalatal clefting and absence (or failure) of prior alveolar bone grafting [63–66]. The degree of ossifcation of the zygomaticomaxillary buttress also plays an important role in the results of facial protraction therapy. Earlier stages (younger age group) of ossifcation are associated with a greater span of movement and skeletal and dental changes. Later stages of ossifcation (older age group) are associated with a smaller span of movement and mainly dentoalveolar changes [67, 68]. Today, skeletal anchorage is slowly replacing traditional tooth borne anchorage on account of better control of degree of rotation of the mandible and greater potential for skeletal movements [69, 70]. In patients who are less co-operative, one can consider using a modifed technique with inter-maxillary elastics between a miniplate secured to the zygomaticomaxillary buttress region posteriorly and another miniplate secured to the mandible anteriorly (Bone-anchored maxillary protraction - BAMP). This technique has provided promising results which are comparable to traditional reverse facemask therapy. However, this modifcation can be performed only after the eruption of the mandibular canine to allow for plating in the anterior mandible [69, 71, 72].

Very rarely will a child present with severe or extreme regression in this age group. Rigid external distraction (RED) is the only option available for the correction of such a severe discrepancy and is mainly used in syndromic patients presenting with moderate to severe obstructive sleep apnea and in patients with a poor psychological status. RED allows for high osteotomies as it does not rely on rigid fxation techniques to secure the distractor. This helps avoid injury to tooth follicles in the growing patient while simultaneously correcting para-nasal hollowing. On the contrary, internal total maxillary distraction (ITMD) and anterior maxillary distraction (AMD) cannot be used as the lower-level osteotomies used in these procedures will damage the un-erupted dental follicles. The plates of the internal distractor also need to be secured to the bone with screws, which will also cause damage to the tooth follicles.

In spite of the above treatments, it is diffcult to maintain results in the long term on account of continued mandibular growth. Thus, surgery will mostly be required once the patient reaches skeletal maturity to correct any residual skeletal deformity. However, the fnal amount of maxillary advancement will be much lesser resulting in increased postoperative stability of the cleft maxilla.

#### **75.7.3 Age 12–16 Years** (Fig. 75.3)

All permanent teeth (except the third molars) have erupted. The absence of un-erupted dental follicles makes procedures like AMD and ITMD (internal total maxillary distraction) feasible in this age group. Due to defcient arch length, there may be moderate to severe crowding. Some permanent teeth may have remained un-erupted, impacted, or erupted ectopically adding to the complexity of the treatment. If alveolar bone grafting has not been done prior or has failed, it needs to be performed during this phase. Large oronasal fstulae, if present, also need to be closed in preparation for orthognathic surgery.

If the regression is mild to moderate, one can consider camoufage orthodontics, maxillary protraction therapy, or AMD in order to create an acceptable occlusion. Alternatively, we can choose to wait and watch and directly correct the maxillary hypoplasia once growth is complete (Fig. 75.4a, b).

Severe to extreme maxillary regression is preferably treated with AMD. The available span of most commercially available hyrax screws does not exceed 13 mm. Thus, there are two options available to the clinician: repeat the AMD twice in a single stage or in a two-staged manner (at least 1 year apart) [50]. The author prefers to repeat the AMD activation twice, in a single stage. This requires the fabrication and immediate application of a fresh appliance, once the frst appliance has attained complete activation of the incorporated Hyrax screw. Great care should be taken to avoid excessive pressure on the anterior maxilla while ftting the new appliance as the callus is not fully mature and large forces may easily destroy it. Alternatively, we can consider total maxillary distraction (ITMD or RED) (Figs. 75.5a–d and 75.6a–f) as long as the patient does not have moderate to severe preoperative VPI (Also see Fig. 70.17).

In spite of the above treatments, it is diffcult to maintain results in the long term on account of continued mandibular growth. Thus, surgery will mostly be required once the patient reaches skeletal maturity to correct any residual skel-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 75.2** (**a**–**c**) Reverse pull headgear therapy in a growing child with cleft maxillary hypoplasia. (**a**, **a1**) Pre-treatment profle and frontal photographs, (**b**, **b1**) Profle and frontal photographs of patient after application of "reverse-pull headgear", (**c**, **c1**) Post-treatment profle and frontal photographs demosntrating an improvement in the patient's profle

**Fig. 75.3** Treatment plan for age group 12–16 years

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 75.4** (**a**, **b**) Severe reverse overjet at 14 years of age and mild VPI. Anterior maxillary distraction was performed (AMD). Final correction with orthognathic surgery to be done after 16 years of age

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 75.5** (**a**–**d**) Use of internal maxillary distraction in the management of CMH. (**a**) Intra-operative positioning of internal maxillary ditractors, (**b**) post-distraction picture prior to the removal of distractor

devices, (**c**) Pre-operative lateral cephalogram and (**d**) Post-operative lateral cephalogram demonstrating ditractor in-situ

etal deformity. However, the fnal amount of maxillary advancement will be much lesser resulting in increased postoperative stability of the cleft maxilla.

#### **75.7.4 Age 17 Years and Above** (Fig. 75.7)

If prior alveolar bone grafting has failed or has not been performed, a decision should be made as to whether it needs to be performed or not. Large oronasal fstulae, if present, need to be closed in preparation for orthognathic surgery.

If the regression is mild to moderate and VPI is absent or negligible, then either total maxillary distraction, AMD, or orthognathic surgery can be performed. Orthognathic surgery is preferred in this scenario as we can achieve immediate improvement in facial profle and occlusion (Figs. 75.8a–h, 75.9a–h). If there is moderate to severe VPI preoperatively, then it is advisable to perform AMD to avoid further deterioration of the same.

If the regression is severe to extreme and the VPI is absent or negligible, then either orthognathic surgery (Fig. 75.10a–f), AMD, or TMD can be performed. AMD may have to be repeated twice in the same sitting or in a stage manner as described previously. If optimal esthetics is the goal, then AMD followed by conventional LeFort I maxillary advancement is the ideal treatment plan (Fig. 75.11a–g). The only drawback of this procedure is the prolonged treatment duration as a minimum waiting period

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 75.6** (**a**–**f**) Patient treated with rigid external distractor (RED). (**a**, **b**) Pre-operative frontal and profle photographs, demonstating hypoplastic midface and concave profle. (**c**, **d**) Frontal and profle pho-

tographs showing RED in situ. (**e**, **f**) Post-operative frontal and profle photographs demonstrating good midface fullness and a convex facial profle

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 75.7** Treatment plan for age group 17 years and above

of 1 year is needed between both surgeries. If there is moderate to severe VPI preoperatively, then it is advisable to perform AMD to avoid further deterioration of the same. As a means of saving time or if the mandible is truly prognathic, AMD and TMD can be combined with a mandibular setback (using bilateral sagittal split osteotomy) in a simultaneous or staged manner to reduce the span needed to be distracted [73].

#### **75.8 LeFort I Procedure for Cleft Maxillary Hypoplasia**

The protocol preferred by the authors is described below.

#### **75.8.1 Preoperative Investigations**

The preoperative investigations are described in Box 75.11.

*Chronic Maxillary Sinusitis* Most CLP patients suffer from chronic maxillary sinusitis on account of the presence of nasal obstructions and residual oronasal fstulae. It is the author's opinion that such patients need to be referred to an ENT specialist at least 3 months prior as active sinusitis affects the quality of the bone in the maxilla.

#### **Box 75.11: Preoperative Investigations**

#### Primary Investigations

Clinical diagnosis, pre-anesthetic assessment (blood investigations, chest x-ray, ECG, additional investigations for any signifcant medical history), facial photographs, cephalometric analysis (lateral cephalogram and postero-anterior cephalogram), articulated study models with bite registration and facebow transfer, dental model analysis, orthopantomogram, perceptual speech assessment, video nasoendoscopy (or video fuoroscopy) for velopharyngeal insuffciency, psychological screening, and patient education regarding realistic expectations

Adjunctive Investigations

3D computed tomography scans, stereolithographic model, sleep studies, and 3D virtual surgical planning

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 75.8** (**a**–**h**) Mild reverse overjet and no preoperative VPI. The patient was treated with single jaw orthognathic surgery (maxillary advancement). (**a**, **b**) Pre and post-operative frontal photographs. (**c**, **d**)

Pre and post operative profle photographs (left side). (**e**, **f**) Pre and post-operative profle photographs (right side). (**g**, **h**) Pre and post-operative lateral cephalograms

#### **75.8.2 Preoperative Preparation**

A single dose of 8 mg dexamethasone (half-life of 36–54 h) is given preoperatively to help reduce postsurgical airway and maxillofacial edema. It also has a synergistic analgesic effect when combined with postoperative analgesics. As a only a single dose is given, it is associated with minimum side effects [74, 75]. A single dose of 1 gm tranexamic acid is given 1 h preoperatively as it helps reduce intraoperative blood loss [76].

#### **75.8.3 Intubation**

Nasal intubation is preferred followed by submental intubation. In case a pharyngeal fap or nasal obstruction (enlarged inferior turbinates or deviated nasal septum) is present, it is advisable to perform fber-optic assisted awake intubation. Alternatively, it may be necessary to pass a more rigid tube or catheter initially after which the endotracheal tube is passed over it.

The author always prefers to use a fexometallic nasoendotracheal tube as the tube is able to maintain its integrity even if damaged during the LeFort I osteotomy on account of the additional strength imparted by the metal coils.

#### **75.8.4 General Anesthesia**

The author commonly uses hypotensive anesthesia during orthognathic surgery as it provides a clean hemostatic feld, reduces blood loss, and shortens hospital stay. There is an association between hypotensive anesthesia, forces generated during pterygomaxillary dysjunction, and optic nerve damage. Risk for optic nerve damage increases when hypotensive anesthesia is used in head and neck surgery which is

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 75.9** (**a**–**h**) - Moderate reverse overjet and mild preoperative VPI. The patient was treated with orthognathic surgery alone (maxillary advancement and advancement genioplasty). (**a**, **b**) Pre and post-opera-

tive frontal photographs. (**c**, **d**) Pre and post operative profle photographs (left side) (**e**, **f**) Pre and post-operative profle photographs (right side). (**g**, **h**) Pre and post-operative lateral cephalograms

prolonged (>6 h) and large amount of blood loss (> 1 l) has taken place [77–82].

A larger amount of force is needed for pterygomaxillary dysjunction in CLP patients on account of the thicker pterygomaxillary junction. The stray forces, generated as a result of the dysjunction, can dissipate toward the orbital cavity and optic foramen with a magnitude potent enough to cause damage to the optic nerve. This is possible due to the orbital extensions of the palatine and sphenoid bones [7, 83, 84]. Thus, the author prefers to maintain hypotensive anesthesia during the entire orthognathic surgery except during pterygomaxillary dysjunction.

#### **75.8.5 Cleft LeFort I Osteotomy** (Video 75.2)

In cases of unilateral CLP, a routine incision in the height of the maxillary vestibule is used, and care should be taken that it extends only to the mesial surface of the frst maxillary molars on both sides [7, 30, 85] (Refer Chap. 69 on Maxillary orthognathic procedures).

In cases of bilateral CLP, the incision is modifed such that it extends from the lateral incisor to mesial surface of the frst molar on both sides. A vertical stab incision is made in the midline to allow for placement of the nasal septal osteotome. This is to preserve blood supply to the pre-maxillary segment as most of its blood supply comes from the upper lip [2, 7, 28, 30].

Frequent surgery in the cleft maxilla leads to creation of scar tissue in the buccal, palatal, and upper lip regions. This scar tissue has compromised vascularity and healing ability. Therefore, it is essential to maintain an adequate soft tissue pedicle. There have also been suggestions to use modifed vertical incisions instead of circumvestibular incisions, but it increases the diffculty of the procedure manyfold due to poor access and visualization [2, 3, 86]. Careful and gentle retraction of tissues (especially the pedicles) is essential throughout the procedure and especially during the down-fracture process.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 75.10** (**a**–**f**) Severe reverse overjet and mild preoperative VPI. The patient was treated with bi-jaw orthognathic surgery. (**a**, **b**) Pre and post operative frontal photographs. (**c**, **d**) Pre and post operative profle photographs. (**e**, **f**) Pre and post operative lateral cephalograms

The nasal mucosa is routinely elevated from the walls and foor of the nasal cavity prior to starting the LeFort I osteotomy. In the cleft maxilla, there is no intervening bone between the oral and nasal cavity in the region of the cleft; instead, the nasal mucosa is fused to the palatal mucosa due to the previously performed palatoplasty. This tissue should be sharply dissected close to the nasal foor, and care should be taken to avoid perforating the palatal mucosa. This step also aids in the down-fracture and mobilization of the maxilla.

The cleft maxilla usually exhibits para-nasal hollowing. Hence, the routine LeFort I osteotomy may not suffce for complete correction of cleft maxillary hypoplasia. Instead a high LeFort I osteotomy is used which has the added advantage of correcting the para-nasal hollowing as well [7, 30, 86]. Care should be taken to avoid damage to the tooth roots and the infra-orbital nerve as it exits from the infra-orbital foramen (Fig. 75.12). One should keep in mind that the descending palatine artery is closer to the lateral pyriform rim while performing the lateral nasal wall osteotomy.

To completely mobilize the maxilla during a LeFort I osteotomy, it is necessary to perform a pterygomaxillary dysjunction which separates the maxilla from the pterygoid plates. The maneuver is essentially blind and involves orienting a pterygoid chisel (curved osteotome) in a downward, medial, and anterior direction such that it engages the lower part of the pterygomaxillary fssure while maintaining a safe distance from the internal maxillary artery [87–89].

Studies have revealed that the medial pterygoid plate is shorter and the pterygomaxillary junction is thicker in cleft patients as the region around the hamular notch is fre-

**Fig. 75.11** (**a**–**g**) Extreme reverse overjet and mild preoperative VPI. 1st stage corrected by anterior maxillary distraction (AMD). Note the persistent para-nasal hollowing that is only partially corrected by AMD. 2nd stage completed by bi-jaw orthognathic surgery (OGS) with improvement in para-nasal hollowing. (**a**) Pre-operative profle photo-

quently manipulated during palatoplasty. The shorter medial pterygoid plate, by virtue of its smaller dimensions, may be more prone to fracture which increases the risk for vascular complications [87, 88]. Furthermore, the thicker pterygomaxillary junction requires a larger magnitude of force to achieve adequate separation. The usage of greater force leads to less control over this blind manoeuvre, thus increasing the risk for vascular complications (internal maxillary artery damage, carotid cavernous sinus) and neurologic (optic nerve damage) and skull base fractures (sphenoid fractures) [84].

graph. (**b**) Profle after stage 1 correction wthe AMD. (**c**) Profle after stage 2 correction with orthognathic surgery. (**d**) Pre-operative lateral cephalogram. (**e**) Lateral cephalogram after stage 1 - AMD. (**f**) Postconsolidation lateral cephalogram. (**g**) Lateral cephalogram after stage 2 -orthognathic surgery

There have been many modifcations suggested to the original technique with an intention to reduce complications [87, 88, 90–95]. However, their use has never been documented widely in CLP cases. One may also attempt to use a piezo-surgical instrument or sequentially increase the size of the osteotomes to help reduce the force required for fnal pterygomaxillary separation [96, 97]. Another important consideration would be the preference of a third molar vertical osteotomy cut instead of a pterygomaxillary disjunction. This manoeuvre is anatomically less hazardous, allows greater mobility of the segments, allows a larger vascular pedicle to be maintained and permits the use of interpositional bone graft in the osteotomised area, after the advancement in order to prevent relapse.

Once pterygomaxillary dysjunction has been performed, the maxilla is down-fractured using leverage or specialized instruments like the Smith's spreader. If the

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**Fig. 75.12** Modifed high LeFort I osteotomy (blue) cut to help correct para-nasal hollowing. Avoid damage to the infra-orbital nerve (yellow) and roots of teeth (white) while making the osteotomy. The pyriform rim is marked in orange

nasal mucosa has not been dissected from the palatal mucosa previously, then it has to be done at this point [2, 7, 30]. After the down-fracture, it is important to suture the divided edges of the nasal mucosa to regain continuity of nasal lining. In the author's opinion, the edges of the divided nasal mucosa are a common source of bleeding postoperatively if left un-sutured (Fig. 75.13a, b). The presence of nasal obstructions like enlarged inferior turbinates can be corrected at this time.

After the down-fracture, the process of mobilizing the maxilla is done in a gradual progressive manner as the scarred tissues are less compliant. Specialized instruments like the Tessier's mobilizer can be used. If a pharyngeal fap is present and is impeding maxillary advancement, it may need to be incised. The maxilla is fnally advanced to its desired position and should be seated in a passive manner. Signs of resistance at this point may indicate that the maxilla has not been adequately mobilized, and the previous steps need to be revisited. If resistance to the desired maxillary position persists, then one must consider to switch to maxillary distraction or setback the mandible to avoid postoperative relapse. In situations where an alveolar bone grafting procedure has not been performed, or where the take of the grafting is sub-optimal, the cleft maxilla may present as a two-piece (unilateral cleft) or a three-piece (bilateral) maxilla. This may necessitate the use of transverse maxillary plating (Fig. 75.14a, b), for stabilization of the segmented bone.

There may also be need for segmental osteotomies as it is diffcult to completely co-ordinate both arches with presurgical orthodontics on account of the variable anatomy of the cleft maxilla. The cleft alveolar gap can be opened or closed

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 75.13** (**a**) Torn nasal foor mucosa after down-fracture of maxilla. The endotracheal tube is visible. (**b**) The torn edges should be sutured back to prevent postoperative bleeding

**Fig. 75.14** Transverse plate across maxilla for stability during LeFort I osteotomy in a cleft. (**a**) Unilateral cleft of maxilla (**b**) Bilateral cleft of maxilla

to facilitate alveolar bone grafting or close alveolar fstulas. It can widen the maxillary arch within acceptable limits, allow differential movement of greater and lesser segments, align the occlusal plane, and maximize intercuspation to improve postoperative stability [98].

The presence of a persistent oronasal fstula and alveolar cleft defect requires careful soft tissue closure and bone grafting. One can also augment the defcient area along the lateral piriform rim on the cleft side to improve the contour of the alar base. The maxilla can fracture at the cleft alveolus site into two segments during the down-fracture and mobilization, even when the alveolar cleft site has been previously grafted. A preoperatively fabricated surgical palatal stent helps stabilize the maxilla in this situation.

Rigid fxation with mini plates and screws is preferred to stabilize the maxilla in its fnal position with a preference for the lateral pyriform rim and zygomaticomaxillary buttress regions as the bone here is thicker [83, 99]. One should pay attention while suturing and prevent entrapment of soft tissues into the osteotomy sites. The soft tissue of the upper lip may be tight with a shallow vestibular depth and defcient vermilion show that may become worse following maxillary advancement. "V-Y" closure can be used to reduce lip shortening.

#### **75.8.6 Additional Steps Performed on a Caseto-Case Basis**

#### **75.8.6.1 Deciding the Level of Midface Advancement** (Fig. 75.15a–f)

In most of the cases, a traditional LeFort I (Fig. 75.15a) osteotomy is advocated. However, in some rare instances, it may need a LeFort II (Fig. 75.15b) or LeFort III (Fig. 75.15c) osteotomy depending on the severity and the extent of the involvement. As the CMH involves the pyriform, the paranasal, and the zygomatic areas, though not symmetrical, the LeFort I osteotomy design in such situations may need modifcation to involve the para-nasal (Fig. 75.15d) and/or zygomatic (Fig. 75.15e) areas unilaterally (Fig. 75.15f) or bilaterally as the case may be.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 75.15** Levels of midface advancement (**a**) LeFort I, (**b**) LeFort II, (**c**) LeFort III osteotomies. Modifcations of LeFort I osteotomy (**d**), para-nasal extension, (**e**) para-nasal and zygomatic extensions, and (**f**)

conventional LeFort I on the unaffected side and para-nasal extension on the affected side

#### **75.8.6.2 Preserving the Descending Palatine Artery**

Studies by Bell et al. established that the descending palatine artery did not contribute signifcantly to the re-vascularization of the maxilla after a total maxillary osteotomy in routine cases [100, 101]. However, the greater palatine arterial network in CLP patients may become narrow and develop vascular anomalies because of the presence of scar tissue created by the palatoplasty procedure [7, 60, 83]. Considering the unique scenario of the cleft maxilla, it is advisable that efforts should be made to preserve the descending palatine artery and secure it as an additional source blood supply for the osteotomized maxilla [7, 102]. Techniques to identify and preserve the descending palatine artery have been documented in the literature [103–108]. However, the above technique needs to be tailored to the cleft maxillary anatomy as it is highly variable. Studies have established that the distance between the lateral pyriform aperture and the descending palatine artery is on an average 3–4 mm lesser in CLP patients. Similarly, the posterior and lateral distances to the descending palatine artery were greater on in CLP patients on account of the thickened pterygomaxillary junction [7, 83, 84]. The perpendicular process of the palatine bone surrounding the descending palatine artery is also of the dense cortical type adding to the diffculty of isolating the vessel [99]. The author reserves this step only when the patient has undergone a large number of revision surgeries in the palate.

#### **75.8.6.3 Grafting of the Osteotomy Site**

The cleft maxilla is defcient in all three dimensions, and hence its correction requires complex large movements. Cortico-cancellous bone grafts can be placed across the gap created in the region of the lateral osteotomy [2, 3, 7, 86, 109]. The ideal source of autogenous bone grafting is the anterior iliac crest [110]. As an alternative, one can also use autogenous genial grafts, allogenic grafts, or synthetic hydroxyapatite bone blocks [111–114]. The author prefers to graft the osteotomy site only when down-grafting the maxilla or advancing the maxilla more than 10 mm.

#### **75.9 Clinical Morbidity and Psychological Response**

According to Stork et al. and Chua et al., there was no major difference between clinical morbidity between distraction osteogenesis and orthognathic surgery and between grafted and non-grafted patients, the source of graft being the anterior iliac crest [115–117].

Patients undergoing distraction osteogenesis experienced greater levels of stress in the short term. Over time, 1695

the distraction group had a higher satisfaction with life [118–120]. This may be because of the better stability of the distraction osteogenesis in the long term as well as the self-perceived contribution of the patients to the success of their treatment. There is also an aspect of superior soft tissue response to distraction as compared to orthognathic surgery which may improve the final aesthetic result (refer Chap. 87 to read more about Distraction Osteogenesis) [121].

Nonetheless, psychological support from family and friends is recommended for patients undergoing either distraction or orthognathic surgery so as to achieve a better life satisfaction in the long term.

#### **75.10 Stability of Results**

The postoperative stability after orthognathic surgery in cleft patients is lower than non-cleft patients [2, 3, 7, 86]. Maximum relapse in cleft orthognathic surgery occurs in the frst 6 months, and the situation stabilizes 2 years postoperatively [122].

#### **75.10.1 Soft Tissue Envelope**

The presence of scarred tissue in the palate and the lip prevents the maxilla from being adequately mobilized. Though the maxilla might be secured into its desired position with the help of rigid fxation and bone grafting, the excess stress placed on the maxilla due to the scarred soft tissue envelope leads to relapse in both the sagittal and vertical dimensions [2, 3, 7, 86, 123]. The severity of labio-palatal clefting and history of multiple revision surgeries increase the risk for relapse.

#### **75.10.2 Magnitude of Planned Surgical Movement**

The amount of surgical movement is the most important factor that determines the degree of relapse in cleft and noncleft cases. Thus, most surgeons tend to overcorrect by an additional 20% to account for the possible relapse [2, 3, 7, 86, 124].

However, a recent study by Watts et al. [125] suggested that amount of linear advancement was not a major cause for skeletal and dental relapse rate in cleft orthognathic. Studies by Bhatia et al. [59] and Hoffman et al. [126] suggested the same. Nonetheless, the general trend is to perform bi-jaw orthognathic surgery or distract the maxilla if more than 10 mm advancement is needed.

#### **75.10.3 Status of Alveolar Bone Grafting**

Lack of alveolar bone grafting increases the diffculty of performing cleft orthognathic surgery. However, though alveolar bone grafting contributes to transverse stability of the maxillary arch and improve outcomes in orthodontia, it does not improve stability of sagittal, vertical, or rotational movements [122, 124].

#### **75.10.4 Intraoperative Factors**

Inadequate separation at the pterygomaxillary junction due to its thicker form in CLP patients, the presence of a pharyngeal fap, a shallow overbite, and the absence of multiple teeth leading to poor intercuspation may contribute to relapse as well [2, 3, 7, 86, 124]. Segmentation of the maxilla as compared to one-piece maxilla was not associated with greater relapse rates in CLP patients and instead could correct orthodontic and occlusal problems that were distinctive to the cleft maxilla. Nonetheless, no attempt should be made to signifcantly widen the cleft maxilla as using a segmental osteotomy is a highly unstable procedure [98, 127, 128].

In the author's opinion, poor-quality bone in the cleft maxilla makes rigid fxation diffcult and increases the risk for relapse [2, 3, 7]. Thus, it is advisable to always secure plates in the region of thick cortical bone, i.e., the zygomaticomaxillary buttress region posteriorly and the lateral pyriform aperture anteriorly (Fig. 75.16a–c). Bony fenestrations can be encountered in cases with prior AMD during maxillary orthognathic surgery; extra care must be taken during plating the same (Fig. 75.17).

Owing to the large advancements commonly performed in cleft orthognathic surgery, the gap between the osteotomized segments is large. When the contact area between the bony shelves is small, there may be instability or fbrous union between segments which increases the risk for relapse. By grating these gaps, there is increased bony contact which helps in optimal healing. Rarely, the space posterior to the maxillary tuberosity after advancement of the maxilla is also grafted to help prevent relapse [46]. Owing to the hostile environment of the cleft maxilla, it is general consensus that autogenous bone grafts provide the best results in terms of take up of the graft and signifcantly lower complication rates. It is interesting to note that a recent study by Stork et al. [115] suggested that grafting was not a major factor in preventing postoperative skeletal relapse in cleft and noncleft patients contrary to the currently accepted methodology. A study by Hoffman et al. [129] in non-cleft patients suggested the same. The author's opinion is in line with both the above authors and grafts the osteotomy site only when advancing the maxilla more than 10 mm or down-grafting the maxilla.

#### **75.10.5 Timing of Surgery**

As previously mentioned, surgery performed before skeletal maturity is associated with a higher relapse rate in both horizontal and vertical dimensions due to continued growth. This is applicable irrespective of the type of surgery being performed: orthognathic surgery or distraction osteogenesis [21, 23, 24]. Secondary surgery for the correction of residual growth deformities is required after growth is complete. It is

Fenestrations / Weak Bone **a b c**

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**Fig. 75.16** (**a**–**c**) Poor-quality bone seen in the anterolateral and posterolateral walls of the maxilla. Always plate along the lateral pyriform rim and zygomamaxillary buttress (dotted) region which are known to have good-quality bone. Part of the miniplate obscured by the retractor and tissues has been traced for better understanding of the plate position. Blue line denotes line of osteotomy on the dental side

Bone along osteotomy line

fractured & displaced into sinus

Plating Design Along Pyriform Rim and Zygoma-Maxillary Buttress

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 75.17** Large bony fenestration in anterolateral wall of the maxilla at the time of orthognathic surgery. It is commonly found where prior anterior maxillary distraction was done. The presence of such a large fenestration can make plating diffcult

important to note that distraction osteogenesis was more commonly preferred in the growing patient [2, 3, 7, 22, 130, 131].

#### **75.10.6 Degree of Relapse**

A review by Kloukos et al. [120] established that results obtained with distraction osteogenesis were more stable as compared to conventional orthognathic surgery 5 years postoperatively. A review by Saltaji et al. [132, 133] reported average horizontal relapse rates of 10 % in distraction cases and 25–30 % in orthognathic cases for cleft patients. Vertical relapse rates in cleft orthognathic patients were high with an average rate of 40–50 %. Similar results have been documented in other studies and reviews with up to 5-year followups [134–140]. The rate for re-operation in cleft orthognathic surgery was approximately 12.2% [140]. Internal distractors were also found to be more stable than external distractors. This can be attributed to the rigidity provided by the internal distractor during the consolidation phase. The use of rigid fxation with miniplates was attributed with the least amount of relapse in cleft orthognathic surgery [2, 3, 7, 132].

Based on the above evidence, distraction osteogenesis has become the mainstay for the management of severe to extreme cleft maxillary hypoplasia (reverse overjet greater than 11 mm) as the slow distraction of bone and the accompanying histogenic abilities help reduce skeletal relapse. Orthognathic surgery is preferred for mild to moderate cleft maxillary hypoplasia (reverse overjet lesser than 11 mm).

#### **75.10.7 Clinical Suggestions to Avoid Relapse**

Commonly used methods to prevent or control relapse are as follows: overcorrection of the fnal surgical result by 20%, prolonged intermaxillary fxation during the postoperative phase, using face masks with reverse traction of the maxilla, interpositioning bone grafts between the gaps created by maxillary advancement, and performing bi-jaw surgery or distraction when advancements greater than 10 mm are required [114]. A study by Tabrizi et al. [141] established that the use of rigid fxation after the consolidation phase of cleft maxillary distraction did not increase stability of results. In anterior maxillary distraction, it is essential to lock the appliance with wire or acrylic plug during the consolidation phase to prevent backward rotation of the hyrax screw.

#### **75.11 Complications**

A study by Metalwala et al. [142] established that there is increased risk for infection and prolonged hospital stay in patients with craniofacial anomalies undergoing orthognathic surgery. The incidence of complications in non-cleft patients has been reported at 6.4% as compared to 25.2% in cleft patients [83].

Studies by Yamaguchi et al. [140] and Moran et al. [143] revealed that an average of 15–30 % of patients present with perioperative complications. The most common complications were closure failure of pre-existing palatal fstula, velopharyngeal impairment, temporary paresthesia of the infra-orbital nerve, and surgical site infection. A review by Santos et al. [144] established that cleft maxilla patients present with the highest incidence of cranial nerve damage on account of the anatomically higher modifed LeFort I osteotomy cut and excessive forces needed at the time of pterygomaxillary dysjunction. Rare and severe complications like arteriovenous fstula, maxillary aneurysm, cavernous sinus thrombosis, skull base fractures, and maxillary necrosis blindness are more common among patients with craniofacial anomalies but have an incidence of lesser than 0.5% [140, 143, 145]. It has been suggested by Eduardo et al. [146] that the use of piezo-electric surgical instruments in orthognathic surgery is associated with a lower complication rate.

With the author's experience (PM) of approximately 900 cleft orthognathic cases while using the traditional dysjunction technique, there has been no major vascular complication or skull base fractures. However, two patients experienced transient blindness with partial recovery of vision in the long term [79].

#### **75.12 Conclusion**

Skeletal surgery is a critical component of surgical management of CLP. On account of the unique anatomy of the cleft maxilla that has been subjected to previous lip & palate interventions, the conventional LeFort I osteotomy technique and orthognathic surgical principles need to be adapted accordingly. The ultimate goal of treatment should be to achieve intelligible speech and an acceptable appearance with good balance of facial skeleton, soft tissues, and occlusion. Distraction osteogenesis is a useful technique in the management of severe maxillary defciency, but does not replace conventional orthognathic surgery. Maxillofacial surgeons who treat these deformities should be part of a craniofacial team to provide interdisciplinary care for the patient. The aim of the team should be to help the child to develop into a confdent young adult.

**Acknowledgment** Dr. Rahul Tiwari (M.D.S Oral and Maxillofacial Surgery) for manuscript preparation

Designation: Fellow of Orthognathic Surgery

Institutional Address with pin code: Jubilee Mission Medical College and Hospital, Thrissur 680005

#### **References**


associated with facemask and rapid maxillary expansion compared with bone anchored maxillary protraction. Am J Orthod Dentofac Orthop. 2013;144(5):705–14.


of posterior osseous interferences for maxillary impaction in le fort i osteotomy. J Craniofac Surg. 2013;24(3):978–9.


lowing distraction osteogenesis? J Oral Maxillofac Surg. 2018;76(6):1309–15.


injuries in Le Fort I osteotomy: a systematic review. Int J Oral Maxillofac Surg. 2018;10–2.


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**76**

## **Cleft Rhinoplasty**

Sunil Richardson and Rakshit Vijay Sinai Khandeparker

#### **76.1 Introduction**

Rhinoplasties in cleft lip and palate (CLP) patients are considered one of the most diffcult and challenging surgeries to carry out. The reasons understood for this are twofold: the principal reason being the simultaneous involvement of all the layers of the nose, including the skin, cartilage, skeleton and vestibular lining, and the other the signifcant scarring that accompanies multiple previous surgical interventions. The deformity has a major impact on nasal aesthetics as well as function and can range from being absolutely inconspicuous to catastrophic.

The literature is fooded with numerous techniques for ultimate correction of unilateral and bilateral cleft lip-nasal deformities. More recently, most cleft surgeons have started opting for primary rhinoplasties at the time of lip repair with or without presurgical orthopaedics. These early interventions have defnitely improved the nasal deformity and the overall nasal symmetry; however, defnitive rhinoplasty may still be required at a later date as the child grows. Despite all the recent developments in cleft surgery, an optimal surgical modality that addresses the issues of desired nasal form coupled with long-term stability for correction of cleft lip-nasal deformity still fails to exist.

**Disclosure:** Authors have no fnancial conficts to disclose

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_76) contains supplementary material, which is available to authorized users.

Richardson's Dental and Craniofacial Hospital, Chunkan Kadai, Nagercoil, Tamil Nadu, India

R. V. S. Khandeparker

#### **76.2 Pathologic Anatomy**

A clear understanding of the associated complex anatomical and pathological abnormalities is paramount to obtaining desired nasal form and function [1].

#### **76.2.1 Unilateral Cleft Nasal Deformity**

The hallmark of unilateral cleft nasal deformity is a threedimensional asymmetry of the nasal tip and the alar base (Fig. 76.1a–c). The characteristic features include:


S. Richardson (\*)

Department of Oral and Maxillofacial Surgery, Goa Dental College and Hospital, Bambolim, Goa, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1703

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_76

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 76.1** (**a**–**c**) Photographs depicting the pathologic anatomy as observed in unilateral cleft nasal deformity. (**a**) Frontal view showing the deviation of the nasal root towards the non-cleft side with asymmetrical appearing nasal tip. (**b**) Basal view depicting the deviation of the base of the columella to the non-cleft side. Also, observe the wide and horizontally directed nostril on the cleft side. Furthermore, the alar base on the cleft side is directed laterally, posteriorly and inferiorly. (**c**) Pictorial depiction of deviation of the caudal nasal septum (blue) towards the non-cleft side

orbicularis oris muscle pull and asymmetric LLC on the cleft side [4, 5].


overlap type of relationship seen on the non-cleft side. The ULC on the cleft side is also weakened by inadequate skeletal support [8]. The consequence of both these factors is reduced support and collapse of the ULC with deep inspiration.

10. **Compromised internal nasal valve on the cleft side:** This is primarily because of septal bowing into the cleft side at the internal nasal valve together with weakened support of the ULC at the cleft side which causes the cartilage to collapse with respiration.

#### **76.2.2 Bilateral Cleft Nasal Deformity**

The bilateral cleft lip nasal deformity is grossly symmetrical and shares similar clinical characteristics as observed in unilateral cleft deformity [9, 10] (Fig. 76.2a–c). The clinical characteristics include:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 76.2** (**a**–**c**) Photographs depicting the pathologic anatomy as observed in bilateral cleft nasal deformity. (**a**) Frontal view demonstrating a more or less symmetrical deformity with bifd nasal tip and blunting of the alar dome. (**b**) Basal view depicting symmetrical position of the caudal nasal septum, short columella and bilateral displacement of the alar bases laterally, posteriorly and inferiorly with wide and horizontally directed nostrils bilaterally. (**c**) Pictorial depiction of the classical midline position of the caudal nasal septum


#### **76.3 Surgical Timing**

The timing of cleft lip nasal repairs can be divided into primary, intermediate and secondary or defnitive repairs.

#### **76.3.1 Primary Rhinoplasty**

Initially, most surgeons were sceptical with early nasal interventions at the time of cleft lip repair following demonstrations of impairment of nasal and midfacial growth in experimental studies that resulted after large submucosal resections of the nasal septum. However, studies by McComb and Coghlan [7] have dispelled this philosophy and demonstrated that early interventions seldom interfere with growth provided the lower lateral cartilage is only repositioned and not resected. Primary rhinoplasties are now increasingly accepted, and their positive effects on secondary rhinoplasties are well documented.

Primary cleft rhinoplasty is typically carried out at 3 months of age at the time of primary cheiloplasty [15]. An early intervention improves the existing cleft nasal deformity by achieving better symmetry, allowing the nose to grow in a symmetric fashion and potentially improving long-term appearance and the fnal outcome.

The defnite goals of the procedure are highlighted in Box 76.1.

#### **Box 76.1: Defnite Goals of Primary Cleft Rhinoplasty**


The addition of presurgical naso-alveolar moulding device is advocated by some authors in conjunction with primary surgery. The technique delivers continuous low-level pressure on the alveolar segments and is highly successful in shaping the nasal cartilage within the initial 6 weeks due to high levels of circulating maternal oestrogen that makes the cartilage increasingly elastic [17].

The technique helps in bringing the alveolar segments closer thereby narrowing the cleft gap, improving the alar base symmetry, expanding the soft tissue envelope and elongating the columella [18, 19].

#### **76.3.2 Intermediate Rhinoplasty**

Intermediate rhinoplasty is reserved for procedures that are carried out prior to completion of nasal growth, in the time interval spanning between defnitive lip repair and secondary rhinoplasty. The procedures are planned on the lines of conservation with the singular aim to achieve symmetry during continued nasal growth, ultimately creating a defnitive platform for a more successful defnitive repair.

The primary goal of surgery is to correct the abnormal position of the LLC on the cleft side so that there is no exacerbation of the deformity following nasal growth in future. It is imperative to perform a septorhinoplasty or cartilage grafting procedures in the post-adolescence age so that the nasal growth proceeds unimpeded [11].

Intermediate rhinoplasty can be carried out at two distinct time intervals [20]. One corresponds to 4–6 years of age, and this age group coincides with the timing of lip revision if required and also helps in achieving a better nasal symmetry. Also, this is the time when the peer pressure starts to mount necessitating the need for intermediate rhinoplasty in this age group. Furthermore, any lateral vestibular webbing can be dealt with preventing the obstruction of the external nasal valve.

The other instance when an intermediate rhinoplasty can be carried out is after completion of orthodontic alignment and secondary alveolar bone grafting (8–12 years). This helps in creating a solid skeletal platform to affect a longlasting correction of severe nasal deformities.

#### **76.3.3 Secondary or Defnitive Rhinoplasty**

Secondary or defnitive rhinoplasty is performed once the maxillary and nasal growth ceases, which corresponds to 14–16 years of age in females and 16–18 years of age in males [21]. The procedure has to be defnitive and provides an opportunity to introduce aggressive surgical interventions like septorhinoplasty, nasal osteotomies and cartilage grafting manoeuvres without fear of jeopardising the maxillary or nasal growth.

The goals of defnitive rhinoplasty are mentioned in Box 76.2.

#### **Box 76.2: Goals of Defnitive Rhinoplasty**


Most CLP patients present with maxillary hypoplasia and therefore require maxillary advancement surgery in the form of either LeFort I osteotomy, total maxillary distraction or anterior maxillary distraction. The maxillary projection can be improved with these procedures without affecting the nasal dorsum adversely [22]. These procedures also allow for forward movement of LLC and improvement of the tip projection. In scenarios such as this, defnitive rhinoplasty is often carried out after addressing the skeletal discrepancies.

#### **76.4 Preoperative Evaluation**

Prior to carrying out a rhinoplasty surgery, it is prudent to carry out a thorough evaluation of the nose in a meticulous manner. This when backed up with sound knowledge of nasal anatomy can bring about aesthetically pleasing results in cleft rhinoplasty.

#### **76.4.1 History**

It is imperative to address any patient concerns as related to symmetry of the lip and nose, nasal airway, etc. prior to carrying out a rhinoplasty surgery. Any previous nasal surgeries have to be documented accurately. The effects of such surgeries on the postoperative outcomes have to be explained to the patient beforehand.

#### **76.4.2 Physical Examination**

A thorough physical examination involves examining both the external appearance and the internal nasal structures.

**External examination** of the nose must be carried out in accordance with its position on the facial skeleton. Measurements as traced on preoperative photographs can provide a guide in the surgical planning (Fig. 76.3a–d).

**Internal nasal examination** proceeds in a systematic and repeatable manner and is performed using a nasal speculum to evaluate for the nasal function.

When performing the physical examination of the nose, the clinical characteristics of unilateral and bilateral cleft nasal deformities as previously described are looked up for in a systematic manner. Gunter diagrams can be a valuable aid for the purpose of preoperative planning [21].

#### **76.4.3 Photographic Documentation**

#### **76.4.3.1 Two-Dimensional Photographs**

Appropriate documentation of the deformity is made possible by taking preoperative photographs in all views, viz. frontal, basal, lateral and oblique views (Fig. 76.4a–f). These photographs serve diagnostic purpose as well as help in protecting the surgeon in cases of medico-legal implications. The photographs also help in explaining the goals of surgery adequately to the patient. Furthermore, the photographs can serve as a visual guide to the surgeon intraoperatively, helping in implementing the planned surgical goals precisely.

#### **76.4.3.2 Three-Dimensional Imaging**

This method requires a set of devices, viz. an optical system, digital communication network and a computer with a calculation program which helps in determining the shape of the three-dimensional object by transforming the image from analogue to digital form (Fig. 76.5a). The technique is reliable, can be safely employed in child patients due to its nonionising nature and offers both qualitative and quantitative assessments, and the digital model can be employed in the clinical setting immediately. The disadvantages include the cost, long time that is required for patient preparation and data acquisition and inability to measure bony or interactive landmarks.

#### **76.4.4 Radiographic Assessment**

#### **76.4.4.1 Cephalometric Analysis**

Cephalometric analysis aids in evaluating the maxillary position and its possible implications on the patient's nose [21] (Fig. 76.5b). The need for any maxillary advancement surgery and the importance of performing it before any rhinoplasty surgery should be conveyed to the patient. Cephalometric analysis also allows for evaluation of chin position [21].

#### **76.4.4.2 Computed Tomography (CT)/Cone Beam Computed Tomography (CBCT)**

CT scans of the paranasal sinuses in axial and coronal views help in defning the deformation of the septum as well as other intra-nasal structures. CBCT is an attraction alternative to CT with regard to decreased ionising radiation to the patient and image quality for hard tissues on par with CT. No modalities other than CT/CBCT allow for evaluation of nasal septum objectively [23] (Fig. 76.5c).

#### **76.4.5 Facial Casts**

Facial casts have been employed by authors to study the nasal morphology by direct anthropometry [24] (Fig. 76.5d). The technique is found to be objective and cost-effective and

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 76.3** (**a**–**d**) Important angular and linear measurements as traced from preoperative photographs can serve as a guide for preoperative surgical planning

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 76.4** (**a**–**f**) Standard photographic views for cleft rhinoplasty. (**a**) Frontal view. (**b**) Left lateral view. (**c**) Right lateral view. (**d**) Left lateral oblique view. (**e**) Right lateral oblique view. (**f**) Basal view

allows precise recording of selected parameters as the soft tissues are not deformed.

#### **76.4.6 Video Recording**

Some authors [25, 26] have also resorted to video recordings that make assessment of movements possible and eliminates the need for clinical photographs as these can be generated from the video records. The disadvantages include increased time and need for trained personnel with considerable cooperation from the patients.

#### **76.4.7 Functional Assessment**

Function is as important as nasal aesthetics. Functional assessment can be established using rhinomanometry; however the usefulness of such an evaluation is limited.

#### **76.5 Surgical Correction**

#### **76.5.1 Surgical Approaches**

Cleft rhinoplasty can be accomplished using either an open or closed approach.

While primary rhinoplasty can be carried out using either of the two approaches, defnitive rhinoplasty is almost always accomplished using an open approach.

The open approach allows for both superior visual control and enhanced surgical exposure of all the abnormal components facilitating their anatomical reconstruction under direct vision. Furthermore, the approach facilitates nasal sculpting either by suturing or by introduction and fxation of different types of grafts. The approach also helps in saving time when compared to the closed approach. When employing the open approach, a combination of bilateral marginal incisions with an inverted V mid-columellar incision is preferred among most surgeons [27] (Fig. 76.6a, b).

Sometimes, additional skin needs to be recruited in the columella. In such cases, the typical external columellar incision can be modifed. When addressing the unilateral cleft nasal deformity, columellar lengthening can be achieved with the help of an asymmetric V to Y incision on the side of the cleft. The V to Y incision is made in the midline, recruiting the skin from the upper lip into the columella in cases of bilateral cleft nasal deformity. A viable alternative incision in cases of bilateral cleft noses is an upper lip forked faps which achieve columellar lengthening together with narrowing of the central segment [28].

Other viable options include the use of prolabium advancement fap together with an Abbe fap, composite graft of skin and auricular cartilage and skin rim rotation fap [29].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 76.5** (**a**–**d**) Tools for preoperative patient evaluation for cleft rhinoplasty. (**a**) Three-dimensional model of the face. (**b**) Lateral cephalogram for cephalometric analysis for evaluating the maxillary and chin position prior to cleft rhinoplasty. (**c**) (1 and 2): Axial and coronal CT scan views allow for evaluation of the nasal septal deviation objectively (white arrows). (**d**) Facial cast for evaluating the nasal morphology

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 76.6** Open approach for cleft rhinoplasty. A combination of inverted V (**a**, **b**) transcolumellar and bilateral marginal incisions is typically employed. (**a**) Marking of the incision. (**b**) Skeletonisation of the nose using the above incision

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 76.7** (**a**, **b**) Tajima and Maruyama reverse U incision for correction of nostril asymmetry. (**a**) Marking of the reverse U incision on to the external nasal skin on the right side of the nostril. (**b**) Correction of nostril asymmetry following closure (also see Fig. 76.17)

Most patients with unilateral cleft nasal deformity are often disturbed with the nostril asymmetry that accompanies such a deformity. This has been addressed using a reverse U incision as described by Tajima and Maruyama in 1977 [30]. The technique involves extending the marginal incision into a rim incision at the point of the alar web. The skin of the web is incorporated with the LLC fap and vestibular skin, and the fap is suspended both medially and cephalically from the LLC to the ipsilateral ULC and the septum using sutures (Fig. 76.7a, b). This helps in recruiting the external skin of the alar web to the vestibular lining which also helps in addressing the issue of defcient vestibular skin associated with unilateral cleft noses. This incision is well accepted among surgeons for correction of nostril asymmetry.

#### **76.6 Primary Rhinoplasty**

The aim of the surgery is to attain symmetry of the nasal tip and alar base.

#### **76.6.1 Unilateral Cleft Nasal Deformity**

The literature has reported a number of techniques for achieving symmetry in unilateral cleft nasal deformities primarily [15, 31]. The salient points that are common to most of these techniques include:

• Completely freeing the soft tissue attachments of the alar base from the pyriform aperture and maxilla for symmetrical repositioning of the retro-positioned alar base on the cleft side.


#### **76.6.2 Bilateral Cleft Nasal Deformity**

In bilateral cleft nasal deformities, the retro-positioned alar bases are released from the nasal lining laterally and positioned symmetrically by securing the nasalis muscle to the nasal septum on both sides. The nasal muscular ring is reconstructed as performed in the unilateral cleft noses. Nasal tip surgery is not performed at this stage but is carried out at the time of intermediate rhinoplasty [21].

#### **76.7 Intermediate Rhinoplasty**

#### **76.7.1 Unilateral Cleft Nasal Deformity**

The intermediate rhinoplasty addresses two issues in unilateral cleft nose: the asymmetric position of LLC on the side of the cleft and vestibular webbing laterally (Fig. 76.9a–d).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 76.8** (**a**, **b**) Schematic representation of primary rhinoplasty in a unilateral cleft lip nasal deformity case. (**a**) Dissection for access to crura utilising the incisions for lip repair. (**b**) Recreating the cleft side nasal dome using transnasal sutures for better symmetry and projection. The sutures are made to pass through the nose, vestibular lining and

LLCs and through the nasal skin before being reintroduced through the nasal skin and ULC and sutured down within the nasal vestibule. It is important to reintroduce them through the same hole they exited to prevent necrosis of the nasal skin

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 76.9** (**a**–**d**) A case of unilateral cleft nasal deformity in a 6-yearold child managed using intermediate rhinoplasty. (**a**) Preoperative frontal view. (**b**) Preoperative basal view showing the abnormal position of LLC on the cleft side (Left). (**c**) Postoperative frontal view. The abnormal position of the LLC on the cleft side is corrected using an open approach (inverted V transcolumellar incision) and transnasal sutures (black arrow). (**d**) Postoperative basal view showing symmetrical positioning of the LLC on the cleft side (black arrow)

In cases of asymmetric position of the LLC on the cleft side, an open approach is usually preferred that exposes the LLCs bilaterally so that the geometric differences between the two sides can be appreciated and subsequently corrected using suture techniques followed by closure along the columellar incision [33].

In cases of lateral vestibular webbing, a V/Y-type incision or a back cut can be carried out to affect the lateral nasal sidewall lengthening which will subsequently bring the LLC forward [1].

#### **76.7.2 Bilateral Cleft Nasal Deformity**

In such cases, intermediate rhinoplasty corrects the depressed LLCs as well as affects lengthening of the short columella [1, 34] (Fig. 76.10a, b). An open approach is employed for correction of the above-mentioned scenarios. Following exposure of the LLCs, the angle of divergence between the domes is decreased using transdomal suture, helping in increasing the projection of the nasal tip [34].

#### **76.8 Secondary or Defnitive Rhinoplasty**  (Video 76.1)

Despite an excellent primary rhinoplasty, secondary deformities coupled with scarring are bound to occur. These issues are tackled upon by defnitive rhinoplasty. The surgeon's skill and his expertise will ultimately decide the success of primary cleft lip nose repair and the severity of secondary deformities. The success of defnitive rhinoplasty depends on addressing every component of the deformity in a systematic manner beginning with the nasal base and ending with the alar base reduction.

#### **76.8.1 Nasal Base**

Creating a strong base for the nose represents the preliminary step in correction of either unilateral or bilateral cleft nasal deformity, the foundation for which is laid down at the time of primary cheilorhinoplasty with the approximation of the nasal foor with the lip. This is followed by addressing

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 76.10** (**a**, **b**) A case of bilateral cleft nasal deformity in a 5-yearold managed using intermediate rhinoplasty. (**a**) Preoperative basal view showing the abnormal position of the LLCs as well as short columella (black arrow). (**b**) Postoperative basal view. One can appreciate

lengthening of the columella that is achieved (black arrow). The correction of LLCs is also affected bilaterally. An open approach was utilised with bilateral reverse U incision to correct the horizontal orientation of the nostrils

the skeletal defciency in the maxilla and premaxilla and correction of the retro-positioned alar base. In some cases, the nasal sill and the nasal base might still have to be augmented at the time of secondary rhinoplasty using local tissue faps [35].

#### **76.8.2 Septum**

The caudal septum is seen to deviate to the non-cleft side, bowing away from the anterior nasal spine with resultant nasal airway obstruction. This requires resection of this portion of the septum, maintaining at least 1 cm dorsal, and caudal septal segments in the form of a L strut to help in preserving the nasal tip and the dorsal support [21] (Fig. 76.11a–i). When doing so, more than 40% contact point must be allowed between the crest of the maxilla and L strut which helps by subjecting the septum to decreased load forces thereby preventing nasal deformities like saddle nose deformity or ptosis of the nasal tip from developing in the future. It is observed in most cases that despite resecting the deviated portion of the septum, the L strut continues to remain deviated due to residual memory that is present in the L strut. In such cases, sutures can be placed through the ULC and the septum applying force in the direction opposite of the deviation to aid in correcting the asymmetry [36]. In cases of severe septal deviation, one needs to resort to using caudal septal extension graft as struts along the dorsal margins followed by surgical repositioning of the caudal septum [37, 38] (Fig. 76.11). The resected portion of the septal cartilage can itself be used as a spreader graft. In cases where the resected septal cartilage is inadequate, one can use rib cartilage as a spreader graft. The caudal portion of the L strut is secured to the anterior nasal spine with the help of sutures. Some surgeons also prefer to make a notch in the anterior nasal spine to which the L strut can be secured. If there exists any residual memory in the septal cartilage after securing it to the nasal spine, it can be relieved by cartilage scoring with the help of a no. 15 blade.

Access to the caudal nasal septum is achieved using an open approach and by dissecting between the medial crura of the LLCs [21]. From this point onwards, a sub-perichondrial fap can be developed. Make sure that the dissection is in the proper plane. The blue appearance of the septal cartilage serves as a guide to correct plane of dissection. The mucoperichondrial fap should be cautiously raised without perforating the surrounding mucosa to provide superior coverage for a large septal extension graft especially from the rib.

#### **76.8.3 Middle Third of the Nose**

The middle third of the nose has poor support on the side of the cleft and therefore the ULCs tend to collapse resulting in internal valve dysfunction which affects the patient's ability to breathe normally. In such instances, spreader grafts placed between the septum and ULCs on either side and stabilised using sutures can help open the internal nasal valve and improve breathing [39, 40] (Fig. 76.11i).

#### **76.8.4 Nasal Tip or LLCs**

Once the caudal septum is stabilised, attention is shifted to the correction of asymmetric LLC and the nasal tip complex. Various techniques are advocated for the same.


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 76.11** (**a**-**i**) 22-year-old patient with unilateral cleft lip and palate before (**a**–**c**) and 2 months after (**d**–**f**) open rhinoplasty performed to correct the severely deviated caudal septum. (**g**) Intraop picture showing batten grafting. (**h**) Resection of septal cartilage in cases of severely deviated nasal septum, maintaining an L shaped contact (black arrow) for preserving tip and dorsal support. The resected portion can be utilised as a septal extension graft (green arrow). (**i**) Spreader grafts placed between ULCs and nasal septum (black arrows)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 76.12** (**a**–**c**) Schematic representation of techniques for correction of asymmetric LLCs and nasal tip complex. (**a1**, **a2**) Cephalic trimming (before and after). (**b**) Shield grafts, caudal septal extension grafts for improving the symmetry and projection of the nasal tip. Dorsal nasal augmentation is also been shown. (**c1**, **c2**) Lateral crural steal technique


In bilateral cleft nasal deformities, LLCs of either side need repositioning with tip suture techniques. In cases of weak cartilages, septal extension grafts as columellar struts as well as in onlay position need be used for ideal projection [42]. Large nasal tip can beneft from cephalic trimming of both LLCs. The goal is to decrease the angle of divergence between the domal points of the lower lateral cartilages, cre-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 76.13** Alar batten grafting demonstrated in a case of unilateral cleft nasal deformity. The graft fortifes the LLC and removes the concavity of the same (Refer Fig. 76.17i)

ate a more defned nasal tip and provide a strong nasal framework for better tip projection.

#### **76.8.5 Alar Rim (Lateral Crus of LLC)**

The LLC on the cleft side has poor skeletal support on the medial and lateral sides which makes the LLC concave with an introverted contour to the ala [43]. This concavity can be managed with different techniques, viz. suture techniques using horizontal mattress sutures, underlay alar batten grafts, onlay grafts and autocartilage faps [44]. The lateral crus of LLC can also be dissected from the underlying vestibular skin, removed, fipped and resutured in a convex fashion.

Alar batten grafts either are placed below the residual lateral crus as underlay graft or can be placed above it as an onlay graft. This graft strengthens the lateral crus of the LLC and removes the concavity of LLC [39] (Fig. 76.13). Suture techniques such as horizontal mattress sutures also strengthen and fatten the lateral crus of the LLC. Lastly, the cephalic margin of the LLC can be made into an advancement fap which can be advanced to provide support to the remaining LLC. Each of these techniques provides support to the lateral crus of the LLC and fortifes the external nasal valve.

#### **76.8.6 Nasal Dorsum and Nasal Osteotomies**

The following issues are observed when addressing this area in defnitive rhinoplasty.


**Fig. 76.14** Addressing the nasal dorsum and nasal osteotomies. A case of fat and under-projected dorsum managed using modifed Turkish delight technique. (**a**, **b**) Pre op frontal and lateral. (**c**, **d**) Post op frontal

and lateral. (**e1**, **e2**) Schematic representation of dorsal hump reduction. (**f**, **g**) Schematic and clinical lateral nasal osteotomies

©Association of Oral and Maxillofacial Surgeons of India

Dorsal hump should be addressed in conjunction with other aspects of the nose, or else an open roof deformity will be the consequence. The correction is carried out by reduction of the bone by rasping and the ULC using either scissors or number 15 blades (Fig. 76.14e).

• **Thick and wide nasal bones with deviation towards the non-cleft side with wide dorsum:** Such cases require either lateral or paramedian osteotomies to narrow the dorsal width and bring about symmetry. The authors' preferred technique for lateral osteotomies is by introducing a 2–3 mm osteotome transcutaneously to create micro punctures along the planned osteotomy going from low to high [42] (Fig. 76.14f, g). The same can also be carried out by introducing the osteotome transnasally. If this does not affect narrowing of the dorsum adequately, then the authors resort to paramedian osteotomies to create an open roof deformity followed by in-fracturing the nasal bones. This manoeuvre almost always requires placement of spreader grafts to prevent collapse of the internal nasal valve.

#### **76.8.7 Piriform Rim and Pre-maxilla Augmentation**

Cleft noses whether unilateral or bilateral present with skeletal defciency in the region of the premaxilla and piriform rim which brings about posteroinferior displacement of the nose. If this area is left unattended, the fnal result is bound to be asymmetric despite addressing all the other aspects of rhinoplasty well [39]. This area can be augmented using a portion of the rib graft and securing it with a screw (Fig. 76.15). This allows for improving the anterior projection. Other options include the use of silicone implant, cortical one or fat grafting [21].

#### **76.8.8 Nasal Alae**

The nasal alae in cleft noses as discussed previously are usually displaced in a lateral and inferior direction. Correcting the abnormal orientation of the nasal alae represents the concluding steps in defnitive rhinoplasty. This is usually achieved using two techniques, viz. V to Y advancement and Weir procedure (alar resection) along the alar facial groove [46–48]. These two procedures need to be supplemented with augmentation of the piriform rim as well as vertical enlargement of the nostril on the cleft side in order to achieve true symmetry. Vertical enlargement of the nostril can be achieved using skin grafts or composite grafts just inside the ala. Superior results are possible despite not addressing the nostril except from the basal view which will make the vertical height discrepancy of the nostril evident. Weir procedure is used in cases of excess skin laterally and allows for symmetrical correction of the alar base on the cleft side nostril which is usually longer and elongated (Fig. 76.15a–g). It also provides access for carrying out augmentation of the piriform rim using grafts. Nostril retainers are often sutured in place for the purpose of helping in moulding and maintaining the nasal sill.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 76.15** (**a**–**f**) Piriform rim augmentation and alar base reduction using Weir procedure. (**a**, **b**) Pre op and post op basal views. (**c**) Alar base resection. (**d**) Peri alar resection. (**e**) Closure. (**f**) Piriform rim augmentation

#### **76.9 Use of Grafts in Defnitive Rhinoplasty**

Grafts are pivotal to the long-standing success of defnitive rhinoplasty in terms of nasal aesthetics and function. Autologous tissue is the norm and always preferred over synthetic substitutes like Medpor and silicone which presents with higher incidences of infection, displacement as well as possible extrusion. Among the autologous options available, cartilage (harvested from septum, auricle or rib) and bone (harvested from cranium, rib or iliac crest) are widely used.

Cartilage grafts harvested from the septum have the advantage of being located in the same surgical feld, requiring no additional incisions and therefore preventing any additional donor site morbidity. Furthermore, simultaneous correction of septal deviations is possible with the use of this graft. The disadvantages include minimal amounts of cartilage available for grafting and presence of residual memory subjecting it to deformation. When the amount of available septal cartilage is inadequate, auricular cartilage can be the source of grafting. It may offer a large area for graft harvesting, and usually does not induce local sequelae. When larger amount of cartilage is needed especially for the purpose of dorsal augmentation, rib cartilage is an excellent source especially from the right seventh, eighth or ninth rib. This cartilage is present in abundance, is quite sturdy and robust, resists deformation by scar contracture, is easy to shape and also provides superior support for optimising the nasal projection [39]. The disadvantages include graft warpage, increased operating time, visible external scar, post-operative pain and risk of pneumothorax. Another disadvantage is ossifcation of cartilage in older patients [39].

Cartilage grafts are classically divided into contouring grafts and structural grafts.

#### **76.9.1 Contouring Grafts**

These grafts are added to the native osteocartilaginous nose in the coronal plane to improve upon the existing nasal aesthetics. Two most common sites for placement of these grafts are the dorsum and the infratip regions of the nose which help in optimising the tip projection. These grafts are stabilised using either resorbable or non-resorbable sutures or glue. Examples of contouring cartilage graft include dorsal onlay graft or shield-type tip graft.

• **Dorsal onlay graft**: It is used for dorsal nasal augmentation. The rib cartilage is the obvious choice. We have also utilised the modifed Turkish delight (diced Medpor mixed with autologous blood and wrapped in Surgicel) for the same purpose with reasonable success.

• **Shield-type tip graft:** Onlay shield grafts help in defning the nasal tip better, optimise the tip projection as well as provide support and hide any minor tip asymmetries.

#### **76.9.2 Reconstructive Grafts**

These grafts strengthen the cartilaginous framework of the nose which improves upon the existing nasal function. These grafts are placed in the sagittal plane and display long-term stability especially when an open approach is used to secure the same. They allow structural and functional reconstruction of the nasal tip in cases of defnitive rhinoplasty. Examples include spreader grafts, alar batten grafts, columellar strut grafts, etc.


### **76.10 Treatment Strategy for Unilateral and Bilateral Cleft Nasal Deformities**

Nakamura N has devised a treatment strategy for both unilateral and bilateral cleft noses that addresses each anatomical and pathological abnormality that is seen in either scenarios [49].

#### **76.10.1 Unilateral Cleft Nasal Deformity**

The pathologic abnormalities that have been previously mentioned are best explained by Nakamura N by comparing the unilateral cleft nose to a house that is been built on a slope. The mid-pole of the house can be thought to be nasal septum, whereas the roof is the LLC and skin, the lateral pole is the vestibule and the base of the house is the maxillary bone. As the house is present on the slope, the mid-pole and the roof incline towards the downward side. In such cases, a straight house can be built on the slope by up righting the centre pole in the centre of the pillar with expansion of the lateral pole and by lifting the roof upward [49] (Fig 76.16a).

Nakamura N's treatment strategy addresses each anatomical and pathological abnormality that causes the main deformities in unilateral cleft nasal deformity listed in Table 76.1. The author's steps in defnitive rhinoplasty consist of an open approach; septoplasty; repositioning of the lower lateral cartilage; medial and upward advancement of the lip and nose components, the nasal vestibular tissues, the nasal ala, nasalis muscle and the upper part of the lip including orbicular oris muscle; and nasal vestibular expansion with or without bone graft [50].

#### **76.10.2 Bilateral Cleft Nasal Deformity**

The pathologic abnormalities that have been previously mentioned are best explained by Nakamura N by likening the bilateral cleft nose to a house that is compressed by stress. In such cases, normal form of the nose can be created by extending the centre pole at the centre, advancing the roof upwards and extension of the lateral poles on each side (Fig. 76.16b). It is very critical to relieve the stress which in other words means relieving the pull on the nasal tip due to columellar skin shortage [49].

The treatment strategy devised by Nakamura N is based on the principle that the ideal technique of defnitive rhinoplasty should minimise damage to either or both the upper and lower lip tissue. This strategy also addresses each anatomical and pathological abnormality that causes the main deformities of the bilateral cleft lip-nose as shown in Table 76.2. Therefore, the author's secondary correction involves open rhinoplasty, repositioning of the lower lateral cartilages, a caudal septal extension graft, medial and upward advancement of the lip and nose components, nasal vestibular expansion and columella lengthening using a nostril rim rotation fap, if necessary [51].

<sup>©</sup>Association of Oral and Maxillofacial Surgeons of India


**Table 76.1** Treatment strategy for unilateral cleft nasal deformity

**Table 76.2** Treatment strategy for bilateral cleft nasal deformity


Nakamura N et al., J Oral Maxillofac Surg 2010; 68: 2248 [50]

Nakamura N et al, J Cranio Maxillofac Surg 2011; 39: 305 [51]

#### **76.11 Outcomes in Cleft Rhinoplasty**

Over the past few years, there has been an increased emphasis on the functional rather than aesthetic outcomes in cleft rhinoplasty [52]. Techniques like primary cleft rhinoplasty and naso-alveolar moulding have also been laden with complications. Although several studies have compared the different techniques of rhinoplasty to determine which technique offers the best surgical outcome, these studies lack standardised objective measurements to draw any meaningful conclusions.

The data regarding functional outcomes in cleft rhinoplasty is also sparse. In one of the prospective studies with 68 cleft patients, the authors evaluated aesthetic and respiratory outcomes at two intervals, viz. pre- and 6 months postoperatively using an active anterior rhinomanometry, rhinoresistometry and acoustic rhinometry [53]. The study showed signifcant improvement in many parameters. The authors concluded that while aesthetic improvement of the cleft nose is a goal, which can be achieved with regularity, nasal respiration still seems to be a challenge in cleft patients. This study highlights the need of recording functional data to study about the effects of surgery.

The outcome that is clearly documented in literature is the high satisfaction rates in patients undergoing surgery for cleft nose deformity. A study incorporating 35 patients with cleft nasal deformity was carried out by Sandor and Ylikontiola [54]. An open approach of rhinoplasty followed by alar base relocation and asymmetric nasal tip augmentation with auricular cartilage grafts was carried out in all patients. The patients' level of satisfaction was recorded in the form of a survey and interview 2 years post-surgery. A visual analogue scale (VAS) numbered 0–10 was also used by the patients to grade outcome compared to preoperative appearance at four anatomic sites. The study demonstrated highest improvements in VAS score for the tip, followed by alar position and dorsum and symmetry of nostrils. They noted that all patients were willing to undergo such procedure for a second time, if necessary. Two more studies have also reported high patient satisfaction rates for patients undergoing surgery for cleft nasal deformities [55, 56].

#### **76.12 Further Revisions in Cleft Rhinoplasty**

Although secondary cleft rhinoplasty is considered the ultimate revision rhinoplasty, in certain cases like those involving asymmetries or scarring, the patient's overall functional and aesthetic outcome may be compromised necessitating further revisions. It is important to remember that the principles that are followed in revision rhinoplasties are similar to those followed in primary and secondary rhinoplasties. The emphasis should be on early recognition after the defnitive rhinoplasty so that revision is possible before scarring sets in.

#### **76.13 Complications**

The complications noted in cleft rhinoplasty are similar to those noted in the traditional open rhinoplasty in non-cleft patients. As cartilage grafts are employed, there exists a possibility of infection. Over the long term, the grafts, whether autologous, allogenous or alloplastic, can demonstrate failure. There is no difference in the risk of bleeding between cleft rhinoplasty and traditional rhinoplasty. All patients should be made aware of possible need for secondary rhinoplasty, need for revision either major or minor, existence of nostril asymmetry, visible scars, necrosis of the skin, nasal system dysfunction and morbidity associated with the donor site. One can fail to create the nasal contour as desired as well as fail in creating a normal looking appearance, and these are very common fndings in cleft rhinoplasty.

#### **76.14 Conclusion**

Cleft rhinoplasty as a surgical procedure is often complex and complicated due to multiple surgical procedures that the patient needs over the years. Despite all the challenges that the procedure offers, the fnal surgical outcome could serve as a life changer for the patient in terms of aesthetics, function as well as symmetry. One should stick to the concepts of restoring symmetry and defnition to the nasal tip and alar base, realigning and re-establishing the patency of nasal airway and preventing scarring and webbing from jeopardising the outcome. All cases have to be thoroughly planned preoperatively using the right assessment tools, and the surgery should be executed to near perfection. An increased emphasis should be placed on carrying out a primary rhinoplasty procedure keeping in mind that a defnitive rhinoplasty will almost always be required to fne-tune the results.

### **76.15 Case Scenarios**

**Case 1** Figure 76.17 represents a case of right unilateral cleft nasal rhinoplasty in a 20-year-old female managed with defnitive rhinoplasty. The patient presented with the chief complaint of crooked nose and diffculty in breathing from the right nostril. The patient was subjected to thorough clinical examination of both the external and internal nasal anatomy. The following features of the cleft nose were noted: deviated nasal dorsum away from the cleft in frontal view and horizontally oriented right nostril in basal view with deviated base of columella to the left. Deviated caudal septum was also noted with diffculty in breathing in the right nostril. Concavity of the right LLC was also observed in the basal view. In the lateral view, tip ptosis was observed. The patient was subjected to open rhinoplasty approach using inverted V transcolumellar incision with incorporation of the reverse U incision on the right side to correct the right nostril asymmetry. Following skeletonisation of the nose, dissection was carried between the medial crura of LLCs to expose the caudal septum which was resected to correct the septal deviation. *The authors would like to stress on the importance of addressing the nasal septum almost always in all cases when performing a defnitive rhinoplasty in a unilateral cleft nasal deformity*. Substantial amount of septal cartilage was harvested to be used as a caudal extension graft to correct septal deviation as well as to improve tip projection. The cartilage was also utilised as an alar batten graft sutured to the lateral crura of LLC of the right side to correct the concavity of the right LLC. Bilateral spreader grafts were sutured between the ULC and the septum to improve the nasal breathing by improving the internal nasal valve function. Lateral crural steal was performed on the right side to maximise the projection of the nose, and further tip projection was achieved using

**Fig. 76.17** (**a**–**n**) Clinical Scenario 1: A case of unilateral cleft nasal deformity in a 20-year-old female managed with defnitive rhinoplasty. (**a**) Pre op frontal. (**b**) Pre op lateral. (**c**) Pre op basal. (**d**) Incision marking (inverted V with Tajima modifcation). (**e**) Exposure of lower lateral

cartilages. (**f**) Exposure of nasal septum. (**g**) Spreader grafts placement bilaterally. (**h**) Columellar strut. (**i**) Columellar reconstruction and alar batten graft. (**j**) Intra op frontal. (**k**) Intra op basal. (**l**) Post op frontal. (**m**) Post op lateral. (**n**) post op basal

**Fig. 76.17** (continued)

©Association of Oral and Maxillofacial Surgeons of India

#### **Fig. 76.17** (continued)

interdomal sutures. The deviated nasal dorsum away from the cleft was corrected using transcutaneous lateral osteotomies bilaterally in a low to high fashion. Lastly, right alar base reduction using a Weir procedure was carried out to achieve symmetry between the two alar bases. Closure of the incision was carried out using 4-0 Vicryl Rapide sutures. Comparison of the pre- and 4 weeks postoperative photographs demonstrate signifcant improvement in the nasal aesthetics. The patient is very satisfed with the overall result and has no complains of diffculty in breathing.

**Case 2** Figure 76.18a–k represents a case of bilateral cleft nasal deformity in a 6-year-old male managed with intermediate rhinoplasty. On clinical examination, all the features characteristic of bilateral cleft nasal deformity was evident some of which included wide dorsum with bifd nasal tip, horizontally oriented nostrils, tip ptosis and short columella with a wide base. The septum was classically midline. Intermediate rhinoplasty was planned via an open approach in this case. An inverted V transcolumellar incision with bilateral reverse U incisions was planned to correct the horizontal orientation of the nostrils. The goal of the surgery was to primarily affect symmetric positioning of LLCs as well as to increase the length of the columella. Following exposure, dissection of the LLCs was carried out. A columellar strut from medpor was utilised which served to increase the tip projection. Symmetric positioning of LLC's was affected and sutured in place using horizontal mattress sutures. Transdomal sutures were also added to correct the bifd tip and decrease the angle of divergence between the alar domes. A modifed Turkish delight graft was utilised for the purpose of dorsal nasal augmentation, and closure was affected with vicryl rapide sutures. It is important to note that any septal procedures were avoided to prevent growth disturbances. The pre- and 2 months postoperative photographs reveal a dramatic improvement and achievement of the preoperative goals.

**Fig. 76.18** (**a**–**k**) Clinical Scenario 2: A case of bilateral cleft nasal deformity in a 6-year-old male managed with intermediate rhinoplasty. (**a**) Pre op frontal. (**b**) Pre op lateral. (**c**) Pre op basal. (**d**) Exposure of lower lateral cartilages. (**e**) Cartilage delivery after lower lateral steal.

(**f**) Columellar strut for columellar reconstruction. (**g**) Modifed Turkish delight for dorsal augmentation. (**h**) Closure. (**i**) Post op frontal. (**j**) Post op lateral. (**k**) Post op basal

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 76.18** (continued)

#### **References**


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**Part XX**

**Craniofacial Anomalies**

**77**

## **Rare Facial Clefts**

Srinivas Gosla Reddy and Avni Pandey Acharya

#### **77.1 Introduction**

Since ages, congenital deformities were considered evil and wizard, and infants were abandoned to die in isolation. Jean Yperman (1295–1351) valued the congenital origin of the clefts. He additionally characterized the different types of the condition and set out the standards for their treatment. Fabricius ab Aquapendente (1537–1619) and William His of college of Leipzig independently researched and published embryological premise of clefts [1].

Laroche was the frst to separate between common cleft lip or harelip and clefts of the cheek. Further qualifcation was made in 1864 by Pelvet, who isolated oblique clefts including the nose from the other cheek clefts, and drawing on Ahlfeld's work, in 1887 Morian gathered 29 cases from the writing, contributing 7 instances of his own. Morian perceived three unique groups of oblique facial clefts. From that point forward, astounding audits have been composed by Griinberg in 1913, Boo-Chai in 1970, Paul Tessier in 1976 [2] and Millard in 1977 [3].

Craniofacial cleft by defnition is "a fssure of the soft tissues that corresponds as a general rule with a cleft of the bony structures." [1] The greatest research on craniofacial clefts was fnished by Tessier and is credited for the formation of the craniofacial surgery for establishing the framework of the advanced craniofacial surgery by fundamentally breaking down facial clefts and portraying facial osteotomies [4].

Craniofacial clefts are signifcant clefts affecting the face, cranium, or both. These clefts cause distortion of the face and cranium with lacks or abundances of tissue that cleave anatomic planes in a straight fashion [2]. Craniofacial clefts exist in changing degrees of seriousness, and practically every one of them happens along the anticipated embryo-

**Disclosure:** Authors have no fnancial conficts to disclose.

GSR Institute of Cranio-maxillofacial & Facial Plastic Surgery, Hyderabad, Telangana, India

logic lines. These clefts can be either complete or incomplete and can seem alone or in relationship with other facial clefts. Seriousness of craniofacial clefts fuctuates extensively, running from a scarcely distinguishable indent on the lip or on the nose or a scar-like structure on the cheek to an extensive partition of all layers of facial structures. Notwithstanding one parted sort can show on one side of the face, while an alternate kind is available on the other side [2, 3].

Craniofacial clefts need comprehensive rehabilitation. Past the physical consequences for the patient, they have monstrous mental and fnancial impacts on both patient and family, prompting disturbance of psychosocial working and diminished nature of life [4, 5].

Cleft repair is a necessary part of the modern craniomaxillo-facial surgical spectrum and remains a challenge on account of inadequate and contorted tissue (minor to major) at the site of the deformity [6]. The outcomes are additionally impacted by the short and long haul aesthetic (soft tissue and facial skeletal appearance) [7] and useful (occlusal and discourse) outcomes [8]. What's more, the kind of careful fx, the specialist's abilities and the compliance of the patient likewise, affects the stylish [9] and utilitarian [10]outcomes. The real test isn't just understanding the hereditary qualities [11], in addition to plan the standard conventions for the surgery in these phenomenal kinds of clefts [12].

#### **77.2 Incidence**

Craniofacial clefts are a lot rarer than the simple cleft lip/ palate deformity [13]. The precise occurrence of craniofacial clefts has not been exactly documented in view of their rarity. However, the reported frequency of craniofacial clefts is 1.5–6.0 per 100,000 live births [14]. The occurrence of uncommon craniofacial clefts contrasted with ordinary cleft lip and palate may vary from 9.5 to 34 for every 1000 [15].

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_77

S. Gosla Reddy (\*) · A. P. Acharya

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1735

Lateral or transverse clefts of the lip are very uncommon and have commonly archived to have a rate of 0.3% of 1.0% of all of the facial cleft deformity spectrum (Boo-Chai 1969; Hawkins et al. 1973; Bauer et al. 1982; Verheyden 1988; Gleizal et al. 2007), or of 0.02% of live births (Kuriyama et al. 2008) [16]. Median clefts of the lower lip are very rare and only 68 cases have been accounted for till date [17].

#### **77.3 Embryology**

Successful treatment of innate craniofacial defects depends on an intensive comprehension of the embryologic procedures prompting their development [18]. There are various interesting highlights that plainly recognize craniofacial improvement from the advancement of different tissues in the body.

One of these novel highlights is the double starting point of craniofacial tissues: the skeletal framework and the vast majority of the connective tissues, including veins, begin from a gathering of cells called the cranial neural crest, while the musculature and some parts of the skull begin from mesoderm.

A second one of a kind component is the unit of intricate, complementary tissue interactions between the neuroectoderm, the mesenchyme, and facial ectoderm that drive ordinary advancement.

A third novel element is the extravagantly arranged morphogenetic developments—brought about by both uninvolved cell removal and dynamic cell movement—that characterize head advancement. Any procedure that upsets the rate, the planning, or the degree of these complex cell conduct can result in a craniofacial birth imperfection.

#### **77.3.1 The Initiation of Craniofacial Development**

#### **77.3.1.1 Establishment and Fusion of the Facial Prominences** (Figs. 77.1 and 72.3)

The basic morphology of the face is established between the 4th and 10th week of human development. The face is formed as a result of fusion of the midline frontonasal prominence and three paired prominences, the maxillary, lateral nasal, and mandibular prominences. Each of these prominences is flled with cranial neural crest cells that originated at different positions along the neural tube.

#### **77.3.1.2 The Frontonasal Prominence**

The frontonasal prominence gives rise to the forehead, midline of the nose, the philtrum, the middle portion of the upper lip, and the primary palate. Interruptions in frontonasal growth often result in a bilateral cleft lip, where the primary palate frequently "everts." In the mildest cases, clefts involving frontonasal prominence-derived structures may be limited to a notch in the vermillion border of the lip. In more severe cases, frontonasal clefts involve all of the tissues of the lip, and these cases may most likely occur because of a failure of fusion between the frontonasal and maxillary prominences.

#### **77.3.1.3 The Lateral Nasal Prominences**

The lateral nasal prominences give rise to the alae of the nose. Clefts that involve the side of the nose often result from a failure in the fusion between the lateral nasal prominences and either the frontonasal or the maxillary processes.

**Fig. 77.1** (**a**–**d**) Embryological representation of fusion of nasal prominences

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.2** (**a**)Tessier classifcation for soft tissue clefting. (**b**) Tessier classifcation for bony clefting

#### **77.3.1.4 The Maxillary Prominences**

The maxillary prominences develop into the upper jaw, the facial halves, the upper lips, and the secondary palate. The nasal passage is divided from the pharynx by the secondary palate, which is formed from the neural crest cells. The palatal shelves frst drop vertically and then rotate into a horizontal plane on the dorsal side of the tongue before fusing. The epithelium of the palatal shelves sloughs off, with only the basal layer of epithelium remaining to cover the later palate.

#### **77.3.1.5 The Mandibular Prominences**

This develops into the lower jaw and lower lip. Clefts of the lower jaw are very rare, presenting with a wide variety of phenotypes, ranging from a vermillion notch on the lip to a complete cleft involving the anterior mandible, chin, tongue, and lower lip and occasionally involving midline structures of the neck up to the manubrium sterni [19].

### **77.4 Etiology and Pathogenesis**

Development of the head and face contains a standout among the most mind-boggling events among embryonic advancement. Disturbance of this frmly controlled course can result in a facial cleft where the facial primordia fail to meet and form the suitable structures [20]. The defnite instrument of the cause of facial clefts is obscure, yet they are accepted to have a multifactorial etiology including a mix of natural and hereditary causes during embryonic development [21, 22]. In India affliation and healthful inadequacies in pregnant mothers are the main cause of clefts [23].

The discussion is as yet in contention between the supporters of Meckel who trusted that clefts were brought about by a developmental arrest and Geoffroy St. Hilaire (1832) who felt that amniotic groups were responsible [15].

Fogh-Andersen previously characterized hereditary factors in clefting, which have been affrmed by segregation analysis [23]. Research in molecular genetics have identifed genes responsible for rare facial clefts which may be syndromic and also for complex non-syndromic variants [24].

The non-syndromic types of orofacial clefts are likely due to secondary gene-environment interactions [25]. Non-syndromic cleft is a heterogeneous disease entity with candidate clefting loci on chromosomes [1, 2, 4, 6, 11, 14, 17, 19].

Four general classes of natural "cleftogens" have been distinguished to date, as follows [26]:

**Radiation.** Huge dosages of radiation have been associated with microcephaly.


Any maternal liquor consumption during pregnancy increases the frequency of orofacial clefting [27]. The impact of maternal smoking also may be responsible [28]. Multiple studies have demonstrated that folate defciency is related with clefts. Pre-birth folic acid supplementation has shown to diminish this hazard. At present, folic acid supplementation is the main empirical safeguard to diminish the frequency of facial clefting [2].

#### **77.5 Classifcation**

An all-round grouping plan that completely envelops, precisely depicts, and coordinates all the different types of orofacial and craniofacial clefts does not exist [2]. Soemmering (1791), Morian in 1886, Degenhardt (1961), the American Association of Cleft Palate Rehabilitation (AACPR) (1962), and Boo-Chai have made huge contributions in building up a classifcation [29–32].

#### **77.5.1 Tessier Classifcation**

In 1976, Paul Tessier depicted an anatomical order framework in which a number is doled out to every abnormality based on its position with respect to the sagittal midline [33].

This framework has moved towards global acknowledgment and allows reliable correspondence among clinicians [34].

This classifcation involves the orbit as the principle reference point. Fifteen areas of clefting have been demonstrated with discussion of their soft tissue and hard tissue involvement [33] (Fig. 77.2a, b).

The numbered clefts relate the soft tissue features to underlying bony involvement.

These have been verifed by operative fndings and more recently preoperative 3D CT assessments [35]. The clefts are radially distributed around the orbit with the midline 0 cleft named as median facial dysrhaphia [33].

#### **77.5.1.1 Number Zero**

The no. 0 cleft is the most widely recognized of the craniofacial clefts [36]. No. 0 and 14 is also called as midline craniofacial dysrhaphia. Clinically, this cleft shows up as an absence of conclusion of the front neuropore [33].

It shows two variants: a true and false middle congenital cleft, with or without related hypo- or hypertelorism [36]. Developmental cause of Tessier no. 0 isn't evident; however, it is realized that midline facial deformities can be followed to a period relating to the third week of gestation [36]. The cleft expresses as a duplication of the crista galli in frontal bone ("skull bifdum" and middle encephalocele), and as nasal septal duplication, and cleft through the columella, maxilla, and lip [33]. This form of cleft may have either a defciency or abundance of tissue: with tissue agenesis and holoprosencephaly toward one side and frontonasal hyperplasia and inordinate tissue (the hyperplasias) at the opposing end. Midway inconsistencies with normal tissue volume possess the center segment of the spectrum [37].

Features of true midline congenital fssure:


Features of the pseudo midline congenital fssure include:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.3** (**a**–**c**) Clinical subclassifcation of Tessier number 0. (**a**) Type I—Involving only vermillion not involving the white roll. (**b**) Type II— Involving vermillion and white roll. (**c**) Type III—Involving vermillion, white roll, and philtrum

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.4** (**a**–**c**) Clinical subclassifcation of Tessier no. 0. (**a**) Type IV—Involving vermillion, white roll, philtrum, columella. (**b**) Type V—Involving columella and tip, supratip, and dorsum of the nose.

Millard [39] classified a middle split of the lip as any vertical cleft through the focal point of the upper lip, paying little heed to the degree (Fig. 77.3a–c). Middle clefts have been isolated into two gatherings by Millard and Williams [39]. The principal bunching includes agenesis of the frontonasal procedure, and the second gathering is portrayed as separated to the middle component. The last is related with different degrees of nasal bifurcation and cranial malformations including hypertelorism [40–42] (Fig. 77.4a–c).

#### **77.5.1.2 Number 1 Cleft**

The number 1 cleft is also called as a paramedian cleft. Skeletally it passes through the frontal bone affecting the olfactory groove along the ethmoid producing hypertelorism (**c1, c2**) Type VI—Involving columella, tips, supratip, dorsum of the nose and frontonasal area

(Fig. 77.5). It also widens the area between the nasal bone and the frontal process of maxilla. The soft tissue component involves the dome of the nose and may involve the alveolus and the lip. It may have a cranial counterpart in No 13 cleft. [33]

#### **Soft Tissue Characteristics:**

Soft tissue characteristics of No 1 cleft include:


**Fig. 77.5** Tessier 1

#### **Skeletal Involvement:**

Skeletal features are as follows:


#### **77.5.1.3 Number 2 Cleft**

Tessier no. 2 clefts are found parallel to the midline Tessier No. 0 clefts [33]. The deformation of the middle third of the nostril rim is a characteristic feature of the Tessier 2 cleft. This produces widening of the nasal bridge and fattening of the lateral side of the nose (Fig. 77.6a–e).

Skeletal features of Tessier 2 clefts are as follows:

1. Alveolar dysplasia from the lateral incisor to the pyriform aperture.


#### **77.5.1.4 Number 3 Cleft**

No. 3 is the oculo-nasal cleft (Morian I). This is also called "medial" orbito-maxillary cleft which passes through the lacrimal segment of the lower eyelid. This paranasal cleft occurs obliquely involving the lacrimal groove [33]. The patient may have microphthalmia [35] but anophthalmia is rare [45] (Figs. 77.7a–c and 77.8a–c).

#### **Soft Tissue Characteristics [35, 46]**

The important soft tissue features of the Tessier 3 cleft are:


Skeletal involvement include the following features:


#### **77.5.1.5 Number 4 Cleft**

The No 4 Tessier cleft is a rare, complex, and gruesome craniofacial malformation [47]. No. 4 is the oculofacial separated I (Morian II). This is a "focal" orbito-maxillary cleft [33].

It may range from a unilateral notch paramedially to large bilateral tissue defects extending from the mouth to the eyes with huge bony fssures [47] (Fig. 77.9a–f).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.6** (**a**–**e**) Tessier 2 clefts ranging from microform defect to more severe

Soft tissue characteristics include:


Skeletal characteristics are enumerated below:


©Association of Oral and Maxillofacial Surgeons of India

#### **77.5.1.6 Number 5 Cleft**

The Tessier No 5 cleft is a very uncommon malformation and is also referred as the oculofacial cleft II (Morian III). This lateral orbito-maxillary cleft gets through the medial third of the lower eyelid [33] (Fig. 77.10a, b).

Soft tissue involvement demonstrates:


Skeletal involvement:

1. The alveolar cleft starts lateral to and travels lateral to the infra-orbital foramen and ends in the lateral part of the orbital foor. There may be associated hypoplasia of the maxillary sinus [48].

©Association of Oral and Maxillofacial Surgeons of India


#### **77.5.1.7 Number 6 Cleft**

This is otherwise called as zygomaticomaxillary cleft which may form an incomplete variant of the Treacher Collins syndrome (Fig. 77.11a, b). It was named as maxillozygomatic dysplasia by Van der Meulen [33, 49].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.9** (**a**–**f**) Tessier 4. (**a**, **b**) Skeletal Tessier 4. (**c**, **d**) Unilateral Tessier 4. (**e**, **f**) Bilateral Tessier 4

Soft tissue involvement of the No 6 cleft is detailed below:

Skeletal involvement is as follows:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.10** (**a**, **b**) Tessier 5

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.11** (**a**, **b**) Tessier 6. Skeletal Tessier 6. (**a**) Unilateral Tessier 6. (**b**) Bilateral Tessier 6

#### **77.5.1.8 Number 7 Cleft**

This is a temporo-zygomatic cleft and is the most wellknown of all the craniofacial clefts [35] (Figs. 77.12 and 77.13a–d). It may occur along with hemifacial microsomia.

Soft tissue features include:


Skeletal qualities include [35, 53, 54]:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.12** Tessier 7

©Association of Oral and Maxillofacial Surgeons of India


#### **77.5.1.9 Number 8 Cleft** (Fig. 77.2)

This fronto-zygomatic cleft situated at the lateral canthus forms the equator of the Tessier craniofacial cleft sphere. It is a part of the zygomatico-frontal dysplasias [49]. The number 8 cleft seldom occurs in isolation and usually occurs as a part of other craniofacial clefts. It corresponds to the cranial occurrence of the No 6 cleft. In bilateral occurrences it is associated with numbers 6 and 7. This shows features similar to the Treacher-Collins and the Goldenhar's disorder with the former showing more skeletal deformities and the latter soft tissue ones [55].

Soft tissue features include [56, 57]:


Skeletal involvement includes [58, 59]:


#### **77.5.1.10 Number 9 Cleft**

No. 9 is a form of the upper "lateral" orbital cleft. The clefting is seen in the lateral third of the upper eyelid and the lateral supra-orbital angle (Fig. 77.14). It is the cranial extension of the number 5 facial cleft [52]. There may be a defcient greater sphenoid wing in this type [60].

Soft tissue involvement shows:


Skeletal involvement:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.14** Tessier number 9


#### **77.5.1.11 Number 10 Cleft**

No. 10 is an upper "central" orbital cleft with the cleft happening in the middle third of

the supra-orbital edge, lateral to the supra-orbital nerve (Fig. 77.15a, b) [33]. This is the cranial counterpart of the No 4 cleft. Both present with similar ocular deformities and may show colobomata of the iris [33].

This cleft causes a large defect in the frontal bone [46]. Soft tissue features include:


©Association of Oral and Maxillofacial Surgeons of India

Skeletal involvement:


#### **77.5.1.13 Number 12 Cleft**

The No 12 cleft shows defciencies in the ethmoid labyrinth and the glabella [46]. This cleft is usually found medial to the medial canthus [35] (Fig. 77.16).

Soft tissue characteristics include:


#### Skeletal involvement:


#### **77.5.1.12 Number 11 Cleft** (Fig. 77.2)

No. 11 is the upper "medial" orbital cleft. This shows coloboma of the medial third of the upper eyelid, with stretching of the eyebrow [33]. This cleft is often associated with the facial cleft No 3 [35]. Van der Meulen incorporated this deformity in his frontal dysplasia group [49].

Soft tissue involvement includes:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.16** Tessier number 12

3. Presence of a V-shaped frontal hairline in the paramedial region of the forehead [35]

Skeletal involvement:


#### **77.5.1.14 Number 13 Cleft**

The number 13 cleft is the cranial counterpart of the paramedian facial cleft 1.

It is situated between the nasal bone and the frontal process of the maxilla passing through the frontal bones and along the olfactory groove [36] (Fig. 77.17).

Soft tissue characteristics include the following:


©Association of Oral and Maxillofacial Surgeons of India

Skeletal involvement:


#### **77.5.1.15 Number 14 Cleft**

No. 14 is the cranial congener of the cleft no. 0, which is the median craniofacial dysrhaphia. The terms frontonasal and frontonasoethmoid dysplasia were utilized by Van der Meulen for this group of deformities [49] (Fig. 77.18a–g).

Soft tissue characteristics:


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.18** (**a**–**g**) Tessier number 14 with variable degree of nasal duplication and hypertelorism


Skeletal characteristics:


#### **77.5.1.16 Number 30 Cleft**

Tessier 30 cleft otherwise known as lower midline facial cleft or median mandibular cleft is a rarity (Fig. 77.19). Median cleft of the lower jaw was frst described in 1819 by Couronne [30].

It is generally constrained to a deformity in the soft tissue of the lower lip.

In its severe form, it may groove or split the mandibular symphysis and at times involve the midline structures of the

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.19** Tessier no 30

neck including the hyoid bone, the thyroid, and even the strap muscles. The anterior part of the tongue may be bifd, showing ankyloglossia [54], with one case of absence of tongue being reported [55].

#### **77.6 Treatment of Craniofacial Clefts**

Surgery for facial deformities involves the best balance of art and science. The restoration of the malformed anatomy requires artistic creativity, while the science lies in the reestablishment of impaired function [57].

From a careful perspective, even microform clefts might deform. Contingent upon the level of distortion, an arranged strategy has been viewed as the treatment of choice [58]. Due to their multifaceted nature; the individual level of cleft involves successful reconstruction and the rehabilitation in practically every one of the cases request multistep and multi-profcient procedure [59]. Besides cautious examination, imaging methods are important to evaluate the individual level of skeletal inclusion. For correct determination current imaging frameworks seen in systems, for example, CT, MRI, and 3D CT, permit better preoperative comprehension of the issue and planning of the surgeries. Analysis ought to be founded on a classifcation relying upon the site and types of defects (morphology) which helps in foundation of a legitimate treatment plan [60] (Figs. 77.20, 77.21, and 77.22a–e).

Institutionalized treatment plans are not constantly conceivable in light of the assortment of craniofacial clefts and dimensions of seriousness. Be that as it may, core values are useful in deciding the best possible planning and stages for restorative surgery [30]. The Australian Craniofacial Unit Treatment Protocol, which is a pioneering center with international acclaim, has recommended the following:


#### **77.6.1 Tessier No. 0–14 Cleft**

Literature reveals that the midline Tessier 0 and 14 clefts are among the most common encountered [5], while the combination of 0 and 14 is the most common combination of non-isolated clefts [61].

**Fig. 77.20** Sailer's morphological classifcation step I

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**Fig. 77.22** (**a**–**e**) Anatomical classifcation of facial, craniocalvarial clefting

The most commonly adapted protocol for Tessier no. 0–14 is modifed from surgical protocol for midline Tessier 0–14 craniofacial clefts (David 2006) (Fig. 77.23).

As per Sailer's morphological classifcation, Tessier 0–14 clefts involve:


Treatment is generally formulated based on the degree of involvement of these zones (Figs. 77.20 and 77.21).

#### **77.6.2 The Orbital Zone and Skull Bone Defect**

#### **77.6.2.1 Resection of Encephalocele**

An encephalocele is a herniation of a part of the cerebral matter through a deformity in the skull. This may contain meninges (meningocele), or meninges, cerebrum, and ventricle (meningoencephalocystocele) [61].

Tessier no. 0–14 is most generally connected with frontoethmoidal gathering of encephaloceles group which can be subdivided into nasofrontal, nasoethmoidal, and nasoorbital types.

The objectives of repair involve:

1. Meticulous repair of skin deformities. This helps prevent contamination and desiccation of brain tissue.


#### **77.6.3 Orbital Hypertelorism**

Hypertelorism is the most common indication for major craniofacial correction in a Tessier 0–14. Treatment strategies are varied and range from medialization of the medial wall of the orbits to total repositioning of the orbital and facial bipartition [63]. Hypertelorism is a physical fnding in many craniofacial malformations, which is characterized by an increase in interorbital distance. It may be a part of a syndrome but it is not a syndrome by itself.

In 1924, Greig called orbital hypertelorism as "ox-eyed" and also coined the term "ocular hypertelorism" [64]. The more accurate term of "orbital hypertelorism" to denote true lateralization of the orbital complex was coined by Tessier in 1972 [65]. Tessier classifed hypertelorism into three degrees based on the interorbital distance [65, 66] (Fig. 77.24).

#### **77.6.3.1 En Bloc Osteotomies** (Fig. 77.25a–d)

Radical mobilization of the orbits to correct increased interorbital distance is one of the most challenging procedures in craniofacial surgery [67].

Paul Tessier was the frst to perform orbital mobilization using a trans-cranial approach [53]. This surgical intervention was planned to eliminate undue risk to the

**Fig. 77.23** Surgical protocol for midline Tessier 0–14 craniofacial clefts

Adapted Surgical Protocol for Midline 0–14 Tessjer Craniofacial Clefts (David, 2006) [16, 17]

#### **Birth to 1 year**


#### **5 years**


#### **10 years until the completion of growth**


#### **Completion of growth**



**Fig. 77.24** Hypertelorism

optic nerve [65]. Converse described in 1968 preservation of the olfactory nerves by performing subcranial U-shaped osteotomy [68]. Schmid described the extra-cranial circumferential orbital osteotomies for medializing the orbits [68], while Jacques van der Meulen described the facial bipartition in 1983 [69]. Medialization of the medial orbital walls and hemifacial rotation do not interrupt midfacial growth and thus were performed before age 5 in the majority of patients. Orbital translocation causes growth disturbances and thus is to be performed after attaining skeletal maturity [63].

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.26** Stereolithographic models—simulation

#### **Pre-op Evaluation**

Pre-op evaluation for orbital hypertelorism includes the following:

External facial measurements

Dental casts

Posteroanterior x-ray cephalometry [70]

Modern aids like computed tomographic scan

Three-dimensional imaging and stereolithographic models [71] (Fig. 77.26)

#### **Facial Bipartition**

The facial bipartition procedure involves the mobilization and rotation of the entire midface in a monobloc fashion (Fig. 77.27a, b). The osteotomy involves the supra-orbital rims frst. It is then continued along the lateral orbital walls in a similar fashion to the LeFort 3 osteotomy and is dropped caudally to involve the dentate segment also in the mobilized segment. The intra-orbital circumferential osteotomies are performed using a combined trans-cranial and trans-facial approach once the hemifacial segments are mobilized, the intervening ethmoids are resected creating space for the upper face to be rotated medially. This causes the maxillary dentate segment and the palate to have a lateral rotation increasing the transverse dimension of the face and correcting the palatal crossbite of the upper posterior teeth. This procedure can also be combined with an advancement of the midface complex by combining it with a LeFort 3 type modifcation [72].

#### **77.6.3.2 Box Osteotomy** (Fig. 77.28a–d)

Correction of orbital hypertelorism done using a box osteotomy may include corrections of associated nasal deformities. Bone and cartilage grafts may be necessary to provide nasal framework. Skin grafts may be required for nasal coverage and may be accomplished by local faps. The box osteotomy is generally preferred when the dental occlusion is normal.

Van den Elzen et al. (2011) advocated waiting until after age 10 (after eruption of permanent dentition) to perform orbital box osteotomy. Monasterio and Taylor [61] supported the use of orbital translocation after skeletal maturity and have stated that early intervention retards midfacial growth. Tessier (1973) noted that neuro-ophthalmological beneft was increased by correcting hypertelorism at 3 years and psychosocial beneft was heightened by operating at 6 years, before schooling begins, or after 12 years to preserve the dentition. Marchac et al. (1999) also described the use of box osteotomies after 12 years of age.

#### **77.6.3.3 Spectacle Osteotomy** (Fig. 77.29a–e)

The spectacle osteotomy is done by performing the transfrontal craniotomy and preservation of frontal bandeau along with trimming of the bone in the periorbital region and around the pyriform aperture with *medialization* of the orbits.

A lateral canthopexy is an integral part of this procedure [48]. The medial canthi should be recognized and anchored using trans-nasal wires. At times this is performed with a miniplate anchor for orienting the wires in the right direction [72]. The plate is secured to the thick nasal bone, and the lower hole is kept at the level of the lacrimal crest. The canthi are independently fxed to these holes bilaterally utilizing steel wires (Also refer Chap. 79 on craniofacial syndromes) [73].

#### **77.6.3.4 Soft Tissue Management**

The midline cleft lip notch can be successfully treated by holding fast to three noteworthy standards (Fig. 77.30a, b):


**Fig. 77.27** (**a**, **b**) Facial bipartition

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.28** (**a**–**d**) Box osteotomy—skin incision for the intracranial correction of the orbital hypertelorism consists of bicoronal incision, transfrontal craniotomy sparing the frontal bar, periorbital osteotomy, block bone removed near pyriform area, calvarial bone graft, miniplate fxation and closure

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.29** (**a**–**e**) Spectacle osteotomy

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.31** (**a**, **b**) Resection of the excess skin of the nasal dorsum and closing in the midline

In managing the 0–14 cleft, the clinician should be able to diagnose if it is a true or a pseudo occurrence. In cases of a true midline cleft, care should be taken to reconstitute the important components of the lip, external nose, and nasal septum. Resection of excess skin also needs to be planned and performed [36] (Figs. 77.31a, b and 77.32a, b).

#### **Nasal Clefts**

Nasal clefts include Tessier no. 2 and Tessier no. 3 clefts.

Principles of surgical management (Fig. 77.33). Because of their rarity and extreme variability, it is not surprising that *standardized* methods of correction have not been established for patients with nasal clefts. Therefore, each case

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.32** (**a**, **b**) Reconstruction of the lip and resection of the excess skin of the nasal dorsum and closing in the midline

Principles of Management of Complex Nasal Clefts


Inventory of Nasal Components


Cartilage

Bone


**Fig. 77.33** Principles of management of complex nasal clefts

must be approached on an individual basis using the basic principles of nasal reconstruction as a foundation.

The fundamental principles and techniques of nasal reconstruction are to assess what is present, what is missing, utilization of available tissue, and importing required tissue as indicated by the deformity.

#### **Inventory of Nasal Components**

Each component of the nose, skin, lining, and support (bony and cartilaginous), must be evaluated in a quantitative and qualitative manner. The quality and quantity of external skin and nasal lining are evaluated for defciency or excess. The integrity of the cartilaginous framework, nasal septum, has to be assessed.

#### **Staged Reconstruction**

Patients with complex craniofacial clefts frequently require multiple staged reconstructive procedures. Planning of these procedures must be tailor-made to each patient. Surgical stages must be planned and executed with all subsequent surgical sessions clearly in mind.

#### **Replace Like with Like**

Whenever possible absent or deformed tissue should be replaced with identical or similar autogenous material.

Bony defects may be present along the cleft from the alveolus to the orbit. It is essential to reestablish a stable anatomic bony base to ensure adequate support for the soft tissue reconstruction of the nose and orbit. Autogenous split calvarial, rib, and iliac graft are the general preferences.

#### **Cartilage**

Free cartilage grafts alone may often suffce to correct small defciencies of the alar rim, nasal rim, nasal dorsum, or tip. Larger defects of the upper and lower lateral cartilages can be replaced using conchal or septal cartilage grafts. Thin bone from the perpendicular plate of the ethmoid can be used to replace upper lateral cartilage.

Small composite chondro-cutaneous grafts from the concha can be used to replace small defects if additional lining is needed. For larger cartilage defects in the area of the upper laterals, septal hinge faps can be used. Reconstruction of lower lateral cartilage can be accomplished using conchal cartilages or chondromucosal grafts from nasal septum.

#### **Nasal Lining**

Adequate lining to the nose is critical to achieve a functional and predictable aesthetic result. This is also essential to reestablish vascularity to the underlying tissue and to minimize contracture of the soft tissues. Local turnover faps are useful for small defects, while larger defects may require vascularized tissue transfer.

#### **Skin**

Small nasal clefts are amenable with local tissue transfer in the form of rotation faps from the lateral nasal area. Onus in simple nasal clefts is given to the reestablishment of the alar rim contour [68]. The use of z-plasty techniques and composite grafts helps in achieving additional symmetry [77].

Downward rotation of the cephalically displaced alar rim is the frst step in this process. This may require the use of a back cut to rotate the alar margin caudally. The triangular defect produced by the alar rotation is then flled by a transposition fap from adjacent areas having excess skin [78, 79].

Descriptions of a nasal dorsal rotation fap (Figs. 77.34a–d and 77.35a, b) for a Tessier 2 cleft and a brow-eyelid-nasal transposition fap for a Tessier 3 are predictable techniques [80].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.34** (**a**–**d**) Design for bilateral Tessier no. 3 cleft—nasal dorsum rotational fap

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.35** (**a**, **b**) Nasal dorsum rotational fap

The nasal dorsum rotational fap design to correct Tessier no. 2 clefts improves alar symmetry at the cost of reduced nostril size. A notch on the affected ala is a major problem to handle in this technique [80, 81].

The forehead-eyelid-nasal transposition fap (Fig. 77.36) technique involves the use of an inter-eyebrow-forehead fap which is pedicled on the tissue of the nasal bridge. The rotation achieved by the fap gives both the alar and nostril symmetry while reducing the need for revision [80].

#### **Reestablish Nasal/Facial Aesthetics**

Optimal reconstruction of the nose should be based on the principle of aesthetic subunits as described by Gonzalez-Ulloa and Castillo (1954) and refned by Burget and Menick

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.36** Forehead-eyelid-nasal transposition fap

(1985). Superior results are better achieved by replacing the entire subunit of the nose rather than simply patching the defect. The achievement of the nasal proportions should be in conjunction with facial proportions though there are many aesthetic and surgical limitations because of associated severe craniofacial deformities. Defnitive nasal reconstruction may need to be delayed or staged as explained, until optimal canthal, orbital, and maxillary relationships are obtained.

#### **77.6.4 Tessier No. 4** (Fig. 77.37a, b)

Tessier no. 4 cleft is a rare, complex malformation which has severe implications on both the soft tissue and skeletal structures of the face. As a general rule, priority needs to be given for reconstructing the soft tissue envelop, and the skeletal repair should in the form of osteotomies or bone grafting procedures need to be deferred until the school-going years. This is due to the fact that early intervention to the bony skeleton may hinder the development of the midface and associated (Resnick and Kawamoto 1990; Kawamoto and Patel 1998) [76].

An important clinical indication that necessitates emergency intervention is exposure keratitis of the cornea and resultant blindness. This depends on the gravity of the cleft deformity. In narrow cases of Tessier 4 cleft, the clefting is more toward the medial side of the orbit which retains a large bony component of the lateral orbit. This lends support to the globe and enables reasonable competence of the upper eyelid to cover the cornea. In such instances the early surgical intervention may be avoided [82]. On the other hand in severe cases, there is total absence of the orbital foor causing the globe to sink downward with the cornea facing upward due to a lax supporting structure. This prevents the upper

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.37** (**a**) Incision for bilateral Tessier no. 4 (**b**) unilateral tessier 4 on left side with tessier 7 on right side

eyelid from being able to protect the cornea, with the resultant problem of exposure keratitis and permanent corneal damage. Such instances produce an emergency, and a repair of the orbital support system is mandated. In cases where an early intervention is not possible due to medical and anesthetic implications, emergency intervention at least in the form of a tarsorrhaphy is performed within 2–4 days of birth.

While treating severe deformities like the Tessier no. 3 and Tessier no. 4 clefts, a "split method" of management can be utilized to handle the anatomical regions individually as given below [83].

The affected regions were divided into three segments:


#### **77.6.4.1 Managing the Lid Segment**

An ectropion like deformity is commonly present. This can be managed using conventional techniques. They include (a) a back-cut release of the lower eyelid to cheek junction and medial advancement of the lower eyelid with medial canthopexy, (b) lower lid resection with inferior layered tarsal strip, or augmentation of the tarsal plate with spacer grafts. However in cases where there is inadequate tissue locally, tissue must be imported into the lower eyelid for optimal results [83]. Some of the commonly used faps for this include the median forehead fap and the nasolabial fap. However, free vascularized tissue transfer techniques also may be adopted [84].

Numerous techniques have been described for the management of the Tessier 4 cleft. But most of them result due to the interdigitating scars produce a sub-optimal outcome [33] (Tessier 1976; Kawamoto 1990). Longaker et al. (1997) proposed the superiorly based nasolabial fap that was transposed to the lower eyelid. Though this technique had an advantage cosmetically, it had that limitation that it was useful only for mild forms of the cleft. The cheek advancement technique described by Van der Meulen [4] had the advantages of being useful even for wider clefts and favorable scars along aesthetic facial subunits. Van der Meulen likewise depicted that it was signifcant for improving the scarring caused by anchoring the cheek fap frmly to the pyriform aperture [85]. However, despite the options available, it is better to understand that a single fap may be insuffcient at times to reconstruct the eyelid [86]. To overcome these challenges, the use of tissue expanders and free vascularized transfers have also been advocated [87, 88].

The Veau III method of bilateral lip repair can be used for correcting the lip component. The last area to be addressed is the naso-malar junction [89].

#### **77.6.5 Tessier No. 5–9 Cleft** (Fig. 77.38a, b)

The primary outcomes that are needed for the correction of these clefts include:


The principles to be borne in mind in the management of the Tessier 5–9 spectrum have been modifed by different surgeons: Tessier (1971) advocated early correction of orbital dystopia – prior to 1 year of age. In all forms of facial clefts that affect the ocular region, priority is given to the preservation of vision by early interventions to prevent exposure keratitis of the cornea. Pre-surgical care includes use of ophthalmic ointments or temporary tarsorrhaphy procedures [48, 89]. Kara and Öçsel (2001) have reported the use of multiple z-plasties for the soft tissue reconstruction as early as 8th day after birth.

#### **77.6.6 Tessier No. 7**

Lateral facial cleft or Tessier no. 7 cleft is generally unilateral in presentation, though may also occur bilaterally. The bilateral form produces more gross clinical appearance with the face being amphibious in nature with an expanded mouth and infero-laterally placed commissures.

The condition is often related to syndromes of the first and second branchial arches. The cleft involves the skin, mucosa, and muscles of the oral sphincter (i.e., the orbicularis oris and the buccinator) [89]. In rare instances the cleft may involve the masseter [90]. This is a condition which may be concurrent with a lot of other deformities mandating a very thorough investigation in any patient exhibiting the classical feature of macrostomia [89].

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**Fig. 77.38** (**a**, **b**) Tessier no 5–9 management

The surgical objectives for the management of the lateral facial cleft have been detailed as follows [90] (Fig. 77.39a–d):


Numerous procedures for the repair of macrostomia have been described in literature; [16, 17, 92, 93, 96, 97] Onizuka 1965; Boo-Chai 1969; Mansfeld and Herbert 1972; Skoog 1974; Talukder 1980; Kaplan 1981; Bauer et al. 1982; Fukuda and Takeda 1985; Verheyden 1988; Yoshimura et al. 1992; Torkut and Coskunfrat 1997; Ono and Tateshita 1999.

Maximal care is exercised on the repair of the involved muscles with an overlapping technique [94, 95]. In severe cases other muscles of facial expression like the buccinator and the risorius also need to be repaired (Ono and Tateshita) [93]. This ensures normalization of both form and function of the perioral region [94].

The skin repair consists of two parts: repair of the cheek wall and commissuroplasty. Commissuroplasty denotes the reconstruction of the skin mucosa junction at the corner of the lips. Care is taken to design the repair in such a way that there is no associated contracture in the post-surgical period. There are various descriptions for the commissural repair. The triangular fap repair of Ono and Tateshita [93]. This procedure produced better aesthetics due to the triangular design of the faps. Kawai et al. in 1998 described an inferiorly based triangular fap taken close to the lower lip to minimize the re-expansion of the commissure in the long term.

Eguchi et al. used the vermillion square fap method for commissuroplasty [96].

Other popular techniques described for the skin repair of the lateral lip element include to direct linear suturing, Z-plasty [94], and W-plasty [96]. The purpose of a Z-plasty is to break the long linear scar. But it is seen that the use of multiple Z-plasty or W-plasty procedures violates the relaxed skin tension lines. Therefore, a single Z-plasty with vertical limb lying in the nasolabial crease is preferred [90].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.39** (**a**–**d**) Tessier no. 7. (**a**) Diagram demonstrating abnormal oral aperture with distorted anatomy of orbicularis oris. (**b1**, **b2**) Clinical presentation of patient with macrostomia. (**c**) Incision marking. (**d**) Angle grafting

#### **77.6.6.1 Bone Grafts**

The establishment of normal contour of the soft tissues is never complete without the much needed skeletal support system. The skeletal reconstruction of craniofacial clefts essentially needs the use of bone grafts to fll and bridge both minor and major defects. The consolidation and take of the bone graft in the recipient site happens in two important steps: (i) the bony union of the joints between the grafted bone and the native bone and (ii) graft remodeling and creeping substitution [97]. Bone grafting can be performed at any age and is generally combined with soft tissue reconstruction [97].

Repairs performed in the early years of life can be accomplished with bone stock from the rib or iliac crest. However, the quality of the bone supplied by the ilium is better suited for this work. The cortico-cancellous graft material can be placed as such or carried over titanium cribs. It is important to note that the general consensus for the use of nonvascularized grafts is for defects less than 6 cm [98].

• Iliac crest grafts are the most favored with a good stock of available cortico-cancellous bone. Generally the anterior iliac crest is preferred as the posterior iliac crest requires a change of position to prone and may not accommodate simultaneous work from two teams. Donor site morbidity rate for anterior iliac crest grafts is around 23% and much less for posterior iliac crest. Complications include postoperative pain, iliac or acetabular fractures or instability, persistent hematoma, herniation of abdominal contents, vascular injury, lateral femoral cutaneous nerve injury, and contour defects along the iliac crest [17].


©Association of Oral and Maxillofacial Surgeons of India


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 77.41** (**a**, **b**) Calvarial bone graft

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**Fig. 77.42** Distraction osteogenesis in the correction of asymmetry

Defects which are larger and demand more complex reconstruction may not be amenable to bone grafting alone and may require well-designed osteotomy techniques [82, 101] or at times, even distraction osteogenesis (introduced by McCarthy and co-workers) [102] to form better contour of the involved skeletal framework and improve function (Refer Chap. 87 on Distraction osteogenesis) (Fig. 77.42).

#### **77.7 Conclusion**

The uncommonness of craniofacial clefts has made the accumulation and complete anatomic documentation of this extensive arrangement troublesome. Preoperative and postoperative CT examinations with 3D reproductions will improve the understanding of these complex deformities. The test of managing these monstrous deformities still challenges the skill and experience of many a craniofacial surgeon [35].

This is an effort to bring a comprehensive account on the varied presentation and management techniques employed in the management of craniofacial clefts of the head and face. We also emphasize the utilization of the brilliant and time-tested diagnostic and surgical principles detailed here to establish new protocols for the comprehensive management of these deformities. Moreover we also advocate that more standardization along with structured investigation and planning methods should be utilized to come to sensible yet effcient treatment models that can be utilized by all for the treatment of this unfortunate set of people.

#### **References**


surgical treatment in a large series of patients. Plast Reconstr Surg. 2008;122:1505–13.


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## **Hemifacial Microsomia (HFM) and Treacher Collins Syndrome**

Manikandhan Ramanathan

#### **78.1 Introduction**

Hemifacial microsomia (HFM) is a three-dimensional congenital deformity of the craniofacial region characterized by abnormal and underdevelopment of the frst and second pharyngeal arches. Due to involvement of multiple structures, this disorder has a broad spectrum of involvement with diverse clinical features [1].

The highly variable phenotypes have probably led to variation in its nomenclature as well, alternatives used being craniofacial microsomia (CFM), otomandibular dysostosis, facio-auriculo-vertebral spectrum, oculo-auriculo-vertebral spectrum, frst and second branchial arch syndrome, otomandibular-facial dysmorphogenesis, and lateral facial dysplasia [2].

This disorder is characteristically unilateral; however, incidence of bilateral cases is 10–15%. Although this disorder was described frst by Carl Ferdinand von Arlt, a German physician in 1881, "hemifacial microsomia" got its name from Gorlin and Pindborg in the early 1960s. Converse et al. proposed the name, craniofacial microsomia, in cases of coexisting cranial deformities where HFM is also associated with vertebral, cardiac, and renal defects, in a condition called as Goldenhar syndrome. It was termed "oculoauriculovertebral dysplasia" (OAVD) by Gorlin. It is also associated with epibulbar dermoids and ear deformities [2, 3].

#### **78.1.1 Epidemiology and Etiopathogenesis**

HFM is the second most common congenital anomaly of the face, with a male predilection and which is more common in

M. Ramanathan (\*)

the right than the left side. The incidence of HFM ranges between 1 in 3500 and 1 in 26,000 live births [4–7].

The cause of HFM remains largely unknown. Poswillo in 1973 reported that hematomas resulting from disruption of embryonic arteries (stapedial artery) in utero produce abnormalities in the development of the structures derived from the frst and second pharyngeal arches. The extent of the hematoma and consequent tissue damage during the frst 6 weeks of gestation determines the severities of deformities. He was able to produce the CFM phenotype in mice, thus proving his theory. He administered teratogens to produce a hematoma of the stapedial artery and the artery of the second arch which resulted in regional necrosis [4] (Fig. 78.1a, b).

The second widely accepted hypothesis is a change in the migration of neural crest cells (Fig. 78.2). Retinoic acid is believed to infuence and alter the migration and distribution of neural crest cells, which may predispose to abnormalities in the pharyngeal arch derivatives. The intake of retinoic acid in humans during the early stages of pregnancy may cause multiple disorders collectively known as "retinoic acid embryopathies" (RAEs); these include variable defects of the jaws and the middle and external ear [3–5]. Apart from retinoic acid, thalidomide, primidone, ethanol and isotretinoin have also been studied as causative agents in HFM through their teratogenic effects [6, 7].

More recent studies have demonstrated an association between HFM and multiple gestations, along with other maternal risk factors such as assisted reproduction, smoking, maternal diabetes mellitus and vasoactive drugs. Moreover, HFM may demonstrate autosomal dominant and recessive Mendelian patterns in families. Positive family history accounts for 50% occurrence of features [8].

Genetic events like duplication of the OTX2 gene (chromosome 14q22.3) have also been researched upon. OTX2 encodes a transcription factor, essential for craniofacial development and anterior brain morphogenesis. Heterogeneity in aetiology along with variable penetrance

**78**

Department of OMFS, Meenakshi Ammal Dental College and Hospital, MAHER University, Chennai, India

Meenakshi Cleft and Craniofacial Centre, Meenakshi Ammal Dental College and Hospital, Chennai, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1769

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_78

**Fig. 78.1** (**a**, **b**) Anatomy of **a** the stapedial artery during embryonic development

©Association of Oral and Maxillofacial Surgeons of India

and expression is postulated to account for the widely variable phenotypic spectrum of HFM [9, 10].

#### **78.1.2 Classifcation Systems**

Various classifcations have attempted to categorize various features of HFM as enumerated below [11–13]:


#### **78.1.2.1 SAT Classifcation**

The skeletal, auricle, and soft tissue (SAT) classifcation.

The SAT and the OMENS (Tables 78.1 and 78.2) classifcations provide an elaborate system covering simple to complex skeletal, soft tissue and neurological involvement. On the other hand, the Kaban-Pruzansky classifcation explains malformations involving the mandible, masticatory muscles, and TMJ. Therefore, it is more useful for orthodontists and maxillofacial surgeons in reconstruction of the mandible and TMJ. Thus, this classifcation has become the gold standard. It involves four classes—

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#### **Table 78.1** SAT classifcation of HFM


**Table 78.2** OMENS classifcation


the Type 1, Type 2A, Type 2B, and Type 3 (Fig. 78.3a–d).

#### **Type 1**

In this category, the TMJ morphology is normal with adequate bulk and function of masticatory muscles. The mandible is slightly hypoplastic and retruded which may project as a mild asymmetry with deviation of the chin to the affected side (Fig. 78.4a, b).

#### **Type 2A**

In this type, the affected side TMJ is shifted anteriorly and medially than its counterpart, but the overall morphology of the condyle and glenoid fossa remains unchanged. The joint is functional associated with moderate muscular hypoplasia. The patient demonstrates moderate hypoplasia of the mandible with occlusal canting or open bite, and the chin is deviated to the affected side.

#### **Type 2B**

There is moderate-to-severe involvement of the joint with condyle and the glenoid fossa grossly hypoplastic. The joint exhibits only rotation movement of the condyle and nearnormal function. Involvement of other facial bones and defciency of masticatory muscles are clinically evident. The patient demonstrates severe asymmetry and occlusal canting with or without an open bite (Fig. 78.5a, b).

#### **Type 3**

There is gross facial asymmetry with severely hypoplastic or absent muscles of mastication. There is associated severe deformity of the skull and orbito-zygomatic complex as well. The mandible is severely affected with a "foating mandible" appearance due to absence of the condyle and ramus (Fig. 78.6a, b). These patients from birth may often present with signs of a compromised airway due to severe degrees of mandibular retrusion.

#### **78.1.3 Clinical Features**

The diagnosis of HFM is challenging owing to its wide phenotypic spectrum. There are no defnite diagnostic criteria and classifcations. The condition is diagnosed based on its clinical features of phenotype ranging from involving the orbit or ear alone to full-blown hemifacial microsomia under development with jaw malformations. For this reason, certain classifcation systems have been established to standardize the assessment in an organized manner and formulate treatment plan accordingly. The areas of examination include various components of the face, i.e. external ear, mandible, temporal bone, zygoma, orbit middle ear, facial musculature, facial nerve supply, and other adjacent bony and soft tissues [2, 5, 7, 14] (Fig. 78.7a–d and Table 78.3).

#### **78.1.3.1 Skeletal Defects**

#### **Cranio-orbital**

The cranial involvement is mainly limited to the squamous part of the temporal bone. Most individuals affected with HFM demonstrate hypoplasia of the zygomatico-maxillary complex. These patients clinically show malar depression with orbital dystopia. The zygomatic bone hypoplasia can lead to alterations in the glenoid fossa.

#### **Maxillomandibular**

The maxillomandibular region is primarily affected due to abnormal development of the frst and second branchial arches. It presents as unilateral facial deformities with reduced dimensions of facial bones in all three dimensions (3D). This produces varying degrees of gross morphological asymmetry of the face and compensatory changes of the contralateral side. The affected side in HFM may vary in severity and also alters the morphology of the so-called normal contralateral side, resulting in gross deviation in 3D, making it a diffcult term as unaffected normal side (Figs. 78.5, 78.7, 78.8a–c and 78.9a–c).

Mandibular growth changes are the earliest manifestations of HFM and are accountable for its classical presentation of facial asymmetry. The ramus of the mandible is either absent or short, with a medial displacement. The contour of the entire mandibular corpus is altered with a shift of the Genium to the affected side. Dental compensations occur for the skeletal discrepancy, which may mask the actual severity of the clinical condition.

©Association of Oral and Maxillofacial Surgeons of India

**d**

**Fig. 78.3** (**a**–**d**) Kaban's modifcation of Pruzansky's classifcation for hemifacial microsomia (HFM). (**a**) Type 1, (**b**) Type 2A, (**c**) Type 2B (**d**) Type 3 Note that the temporomandibular joint (TMJ) in Type IIB is

medially, inferiorly and anteriorly displaced so as to be operationally equivalent to Type III

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**Fig. 78.4** (**a**, **b**) CT scan of patient with left-sided Type 1 Kaban-Pruzansky deformity

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**Fig. 78.5** (**a**, **b**) CT scan of patient with right-sided Type 2B Kaban-Pruzansky deformity

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**Fig. 78.6** (**a**, **b**) CT scan of patient with right-sided Type 3 Kaban-Pruzansky deformity

#### **78.1.3.2 Soft Tissue Defect**

Soft tissue deformities may involve the ear, the seventh nerve and the muscles of facial expression and mastication. Subcutaneous tissues of the face may also be affected to varying degrees. Macrostomia is a common feature along with the presence of skin tags between the tragus and the commissure of the mouth. Lateral facial clefts (Tessiers 6, 7 and 8) may be present involving the soft tissue or hard tissue or both. Function of the cranial nerves, essentially the seventh and rarely the ffth, may be compromised [15, 16]. General soft tissue bulk of the subcutaneous fat and muscles may exhibit defciency (Fig. 78.7). There may also be compromise in the function of the soft palate.

#### **Skin Tags**

Vestigial skin rests also called as auxiliary hillocks or skin tags are usually present along an imaginary line connecting the tragus of the ear to the commissure of the mouth. This is the embryonic line of fusion between the frst and second pharyngeal arches. The tags are frequently present in varying numbers and are associated with cartilaginous remnants, blind sinus tracts that may form inclusion cysts if obstructed [4–6] (Fig. 78.7).

#### **Macrostomia**

Macrostomia occurs as a result of failure of fusion of the maxillary and mandibular processes, leading to a cleft at the oral commissure including the skin and the underlying orbicularis oris (Fig. 78.10a, b). Sixty-one per cent of patients with HFM exhibit macrostomia as reported by Vento and colleagues [12].

#### **External Ear Deformities**

Meurman described a classifcation for deformities of the external ear which was modifed by Marx [17, 18] (Fig. 78.11a–c):


**Fig. 78.7** (**a**–**d**) 15-year-old male, frontal and profle view (**a**, **b**) showing features of hemifacial microsomia such as lateral cleft and preauricular skin tags. (**c**) demonstrates macrostomia and maloccusion while

(**d**) shows exaggerated oral aperture with deviation of mandible to the right side on mouth opening (Also see Fig. 78.30b)

**Table 78.3** Clinical features of hemifacial microsomia and the spectrum of associated anomalies


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 78.8** (**a**–**c**) Radiographs lateral cephalogram (**a**), posteroanterior cephalogram (**b**) and OPG (**c**) showing features of asymmetry. OPG showing defcient body and ramus region

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**Fig. 78.9** (**a**–**c**) Intraoral views showing malocclusion, asymmetric anterior open bite, canting and crowding

©Association of Oral and Maxillofacial Surgeons of India


#### **Muscle Defcit**

Defcits in the temporalis and the pterygo-masseteric group of muscles may be seen in HFM. This also contributes to the skeletal defcit seen. A hypoplastic temporalis may be associated with a hypoplastic or at times absent ramus-condyle unit (RCU) which includes the coronoid process also; a similar association is also evident with the presentation of the pterygo-masseteric muscles and the ramus of the mandible. With cases of increasing severity, the proximal aspect of the zygomatic arch may also be absent with the aponeurosis of the hypoplastic masticatory muscles flling that space. Lateral pterygoid muscle hypoplasia ranges from mild to complete absence and correlates with the extent of the skeletal defect. Hypoplasia of the muscles and defciency of the RCU lead to abnormalities of the TMJ and also with absence or altered joint structures. This often leads to deviation of the mandible to the affected side at rest and on mouth opening (Fig. 78.12a).

**Fig. 78.10** (**a**, **b**) (Left, profle view; right, frontal view): Adult with right-sided hemifacial macrostomia. Note the deviation on mouth opening to the defcient right side. Also note the preauricular skin tags and epibulbar lesions

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**Fig. 78.11** (**a**) Grade 1 mild ear deformity, (**b**) Grade 2 moderate ear deformity, (**c**) Grade 3 severe ear deformity

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**Fig. 78.12** (**a**) Unilateral cleft lip and palate patient with right-sided hemifacial microsomia, Grade 1 ear deformity, right-sided muscle weakness of orbicularis oris, buccinator and orbicularis oculi. (**b**) Deviated smile due to facial nerve deformity

#### **Cranial Nerve Abnormalities**

Approximately 25% of the patients with HFM are affected with cranial nerve defcits, resulting in features ranging from nerve weakness to complete paralysis. The marginal mandibular branch is the most commonly affected followed by the frontalis muscle dysfunction. Rarely, there may be a sensory defcit due to trigeminal nerve involvement along with total involvement of the facial nerve [19] (Fig. 78.12b).

#### **Soft Palate Function**

The cause for the soft palate deviation (to the normal side) in HFM has long been debated. It is proposed that the deviation may be due to a combination of skeletal asymmetry, neurological defcits, and hypoplastic musculature. Literature shows that patients with HFM are predisposed to velopharyngeal dysfunction, even in the absence of a palatal cleft [20].

#### **78.1.4 Radiological Assessment**

Considering the three-dimensional skeletal nature of the deformity, radiological assessment is of paramount importance. Conventional methods of 2D imaging are very helpful and still relevant in assessing the condyle anatomy and extent of asymmetry. Orthopantomogram, posteroanterior cephalogram, and lateral cephalogram should be taken for initial assessment (Fig. 78.9). With the advent of reconstructed 3D imaging, the surgeons can now evaluate the full extent of asymmetry including the cranial base and glenoid fossa (Figs. 78.5, 78.6 and 78.7). Scintigraphy or technetium scan can be done in these cases to rule out apparent hypoplasia due to hyperplasia of one side condyle (Fig. 78.13a, b).

#### **78.1.5 Diferential Diagnosis of Hemifacial Microsomia**

Patient with HFM must be distinguished from those with Goldenhar syndrome, Treacher Collins syndrome, hemimandibular elongation, Parry-Romberg syndrome, juvenile rheumatoid arthritis, Nager syndrome, traumatic postnatal deformity, postaxial acrofacial dysostosis, muscle dysfunction, branchio-oto-renal syndrome (BOR), and maxillofacial dysostosis. The following is a table of distinguishing features of hemifacial microsomia and other entities (Table 78.4).

#### **Hemifacial Microsomia with Cleft Lip and Palate**

The incidence of HFM with concomitant orofacial clefting is a range between 18 and 61%, including presentations of atypical clefts and macrostomia. Fan et al. reported cleft lip with/without cleft palate in 10% of HFM patients. Thus, cleft lip and palate may actually be considered as a part of the HFM spectrum [20, 21]. The laterality and severity of presentation of cleft lip/palate correlate with the severity and side of presentation of HFM. This shows common embryological aetiopathogenesis of HFM and orofacial clefting. However, patients with HFM often present with velar defciencies, leading to hypernasality and velopharyngeal insuffciency. Patients with HFM have a higher incidence of cleft maxillary hypoplasia than non-syndromic cleft patients. The already present abnormality in maxillary growth in HFM may further infuence the midface defciency seen in HFM patients with CL only.

#### **78.1.6 Principles of Management of Craniofacial/Hemifacial Microsomia**

The principles involved in the management of HFM are described below. We have categorized them as per age and the required intervention. Growth considerations are important in formulating treatment plan. Various challenges and treatment methods have been described in literature with focus on the mandible and TMJ reconstruction (Fig. 78.14 and Table 78.5).

#### **78.1.6.1 Neonates and Infants**

Due to the morphological severity of the skeletal deformities, severe functional compromise of the infant's airway can happen after birth. Later on, the presence of a compromised airway can also affect the child's ability to swallow. Hence, the primary management in a neonate should be focused on stabilization of the airway and assisted feeding [22].

#### **78.1.6.2 Airway**

A grossly compromised airway may necessitate procedures to maintain the patency of the child's airway and facilitate the child to thrive. These procedures are neonatal distraction (early distraction osteogenesis), tongue lip adhesion, or tracheostomy [22, 23]. The neonatal distraction has fallen into disfavour due to future unpredictable

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**Fig. 78.13** (**a**) SPECT scan in the case of facial asymmetry. (**b**) Note the active uptake on the left side. Technetium scan can be done to rule out asymmetry due to contralateral condylar hyperplasia


**Table 78.4** Differential diagnosis of Hemifacial Microsomia

growth and possibility of tooth bud damages. Most children presenting with HFM may require assisted feeding using nasogastric tubes or gastrotomy for a few weeks to months.

#### **78.1.6.3 Management of Associated Orofacial Clefting**

The incidence of orofacial clefting occurring with HFM is approximately 10%. The most common form of clefting apart from cleft lip is Tessier 7 facial cleft or macrostomia (Fig. 78.15a, b). The cleft is repaired at 3–6 months of age as per the standard protocol [20]. Cleft lip and palate is more severe in HFM and is associated with worse outcomes. There is tissue hypoplasia and neuromuscular defciency of pharyngeal muscles in patients with HFM. This may be responsible for the development of palatal fstulas and exacerbation of VPI, making management of cleft palate more challenging in such cases.

#### **78.1.6.4 Intermediate Surgical and Orthodontic Management**

Management during the growth phase in HFM differs from that of an adult. Intermediate surgical management includes reconstruction of the external ear which may be planned at 6–7 years as the contralateral ear achieves its full growth during this time. Reconstruction of the cranio-orbital region is usually accomplished between 7 and 9 years as calvarial growth is almost complete during this time. A split calvarial graft to reconstruct the lateral orbital rim and zygoma is the

**Fig. 78.14** Flowchart depicting algorithm of treatment at various levels according to growth

**Table 78.5** Challenges and corrections needed necessary at different ages


graft of choice for reconstruction of defcient zygomaticoorbital region. Surgeons have also used temporo-parietal myoosseous faps for better bulk, contour and retention of graft in place.

Orthopaedic growth modifcation can help these patients to correct occlusion in early stage [23–25]. If the patient has growth potential, with the stimulus provided by a hybrid functional appliance and stretching the soft tissue, growth can be increased on the affected side. The child must have at least 20 mm mouth opening to ensure that proper translation of condyles allows mandible growth. An asymmetric functional appliance (hybrid) that guides the mandible to a new postural position, controls the eruption of teeth and inhibits the soft tissue pressure is used [26]. It directs the developmental growth of mandible three dimensionally.

An orthodontist should constantly monitor the eruption of primary and permanent teeth to improve mandibular defciency and maxillary canting. After the adolescent growth spurt, occlusion can be achieved by means of fxed orthodontic appliances.

#### **78.1.6.5 Correction of Maxillomandibular Complex**

Variations in the maxillomandibular complex management range from early intervention (Figs. 78.16a, b, 78.17a, b and 78.18a, b) to late reconstruction after growth completion. Wait-and-watch policy with only dental and orthodontic interventions may be adopted to reduce the impact of the deformity on the dental occlusion and masticatory function. Defnitive surgical reconstruction of the maxilla, mandible and TMJ can be taken up after cessation of growth [27–31].

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**Fig. 78.15** (**a**, **b**) Surgical correction of lateral facial cleft through commissuroplasty. (**a**) pre-operative photo showing macrostomia. (**b**) post-operative photo demonstrating correction with commissure reconstruction

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**Fig. 78.16** (**a**) Preoperative radiograph-defcient left ramus and body. Note the absence of teeth and tooth buds on the left side. (**b**) Vertical ramus distraction done to achieve symmetry of the mandible and chin

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**Fig. 78.17** (**a**) Intraoperative photograph of the same patient as in Fig. 78.16, showing the horizontal cut. (**b**) Distractor removal after 3 months showing consolidated anatomic bone formation

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**Fig. 78.18** (**a**) Preoperative frontal photo of the same patient in Fig. 78.16 showing left-sided HFM with ipsilateral chin deviation and facial asymmetry. (**b**) Postoperative view showing considerable symmetry of the face

#### **Functional Appliance Therapy**

In cases where the ramus-condyle unit (RCU) shows reasonable function to translate into skeletal growth, growth modifcation with the use of functional appliances does play a role by achieving the following outcomes:


The focus of functional therapy is repositioning the affected condyle to a more inferior and anterior position to enable the mandible to grow and catch up for the intrinsic skeletal defcit [29–31].

#### Ear Reconstruction

Construction of the external ear is a priority in the aesthetic management of HFM patients. Two important factors that affect the ability to construct the ear are the decreased anteroposterior dimension of the upper face and the absence of an adequate platform (i.e. temporal bone cavity). The position and quality of the soft tissue remnants should also be kept in mind while planning surgery. An ear reconstructive surgeon and the maxillofacial surgeon should work collaboratively to determine the most ideal location of the ear relative to the future constructed ramus-condyle unit. Reconstruction options include (1) autogenous rib cartilage, (2) alloplastic options such as Medpore, and (3) tissue-engineered auricular framework. The technique of ear reconstruction is dealt with in detail in Chap. 35 on "Ear Reconstruction".

Though autologous chondral cartilage for reconstruction still remains the best option, it requires a multistage approach to (1) harvest the costal cartilage grafts and create a framework by carving (time-consuming and fxation and retaining of shape challenges), (2) place the graft (positioning as per existing altered morphology), (3) transpose the lobule (soft tissue defciency—tissue expander may have to be used) and (4) create a post-auricular sulcus (with skin graft and split temporalis graft) (Fig. 78.19a, b).

Various materials have been used for alloplastic ear reconstruction with varied results. Porous polyethylene's inert nature and pore size provide and allow for some tissue ingrowth and are safe to use. The alloplastic materials always carry a risk of rejection and infection and may not have accurate sizes and shapes as they are stock implants with limited sizes.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 78.19** (**a**) Pre- and (**b**) post operative photograph of ear reconstruction using rib graft (Also refer Chap. 35 on Ear reconstruction)

Tissue-engineered 3D cartilage reconstruction and its use in regular clinical practice are under trial in many parts of the world though long-term clinical studies still lack regarding its application and optimal results.

#### **Delayed Management in Adults**

Management in adults includes defnitive reconstruction for skeletal and residual soft tissue defcits. With the advent of 3D imaging and computer-assisted surgical planning and printing, precise spatial relationship of the cranial structures with maxillomandibular complex can be studied. This printed models give the surgeon extra weapon outside theatre to simulate surgery and make appropriate decisions before going to theatre. Appropriate treatment plan can be virtually executed, and a CAD-CAM splint can be fabricated to facilitate the accurate surgical outcome [32, 33] (Table 78.6).

#### **Orthodontics for Defnitive Skeletal Surgery**

Orthodontic preparation before defnitive surgical correction of the face is similar to the conventional pre-surgical orthodontic protocols. These include arch levelling and alignments, de-crowding and transverse widening if neces-

**Table 78.6** Principles of management of the deformed temporomandibular joint


sary. Compromise may be necessary in many cases due to the extreme lingual tilt on the affected premolar-molar areas, leaving few options for the orthodontist due to limited bone availability for straightening the teeth [29, 30].

Conventional orthodontic treatment may take longer period and may necessitate the use of anchorage screws for aligning some teeth.

#### **Type 1 and 2A**

In types 1 and 2A, the glenoid and condylar components of TMJ are morphologically intact with minimal hypoplasia. There is no specifc indication for the reconstruction of the TMJ since the joint exhibits normal movement characteristics, and the patient is able to demonstrate adequate mouth opening and masticatory function. Deviation while mouth opening can be seen towards the affected side.

Teeth eruption and angle of its placement will be hampered even in these two types of situations which will require further defnitive treatment. Simultaneous maxillomandibular distraction introduced by Monasterio and Molina is an alternate method for achieving maxillary and mandibular corrections without disturbing the dental intercuspation and occlusal cant [34] (Figs. 78.20a, b and 78.21a, b).

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**Fig. 78.20** (**a**) Preoperative view showing right-sided maxillomandibular defciency. (**b**) Postoperative view showing correction of asymmetry following simultaneous maxillomandibular distraction

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**Fig. 78.21** (**a**, **b**) Radiographs of the same patient as in Fig. 78.20 treated with maxillomandibular distraction (Molina's technique). (**a**) Pre-distraction orthopantomogram demonstrating vertically defcient ramus-condyle unit on the right side. (**b**) Post-distraction xray showing lengthening of the right ramus-condyle unit with the distractor in-situ

#### **Type 2B**

Type 2B patients exhibit severe hypoplasia of both the condylar and the glenoid elements of the joint, thus causing altered functioning of the joint. This greatly reduces or there is a complete absence of the translatory movement of the joint sparing the rotatory movement. The mandible may completely deviates towards the affected side. The arc of rotation completely shifted, leading to malocclusion and scissor bites sometimes.

Distraction osteogenesis can be used to correct the defciency of the mandibular body along with reshaping the glenoid and condylar process. The use of osteotomies to correct the dentofacial deformity is also performed either in the same setting or in a staged manner.

Options for reconstruction of the ramal-condylar unit are another concern which can be approached with costochondral grafting and alloplastic joint reconstruction [35]. The costochondral graft for stimulated growth should be used by the age of 7 years, which can be used as an onlay graft on top of the existing ramal segment in the correct position of glenoid fossa. However, large series of cases with success in this technique lacks the scientifc evidence of growth similar to the unaffected joint, and reports of under- and overcorrection are plenty in literature.

#### **Type 3**

Patients with Type 3 deformities require total reconstruction of the TMJ, i.e. the glenoid-zygomatic complex region and the ramal-condylar unit. For the growing adolescent due to growth completion, glenoid reshaping and costochondral graft reconstruction of the RCU may be undertaken. Total alloplastic joint reconstruction with concomitant orthognathic surgery should be done in adults.

Posterior distraction of existing mandibular segment to create ramal-condylar unit has ended up with limited success due to lack of posterior support of distraction advancing segment and unpredicted movement in 3D dimensions. It was found in authors' experience that the correct direction control of upwardly directing condylar segment is diffcult to achieve towards a missing or defective glenoid fossa, and many times the position can alter more medial and anterior than expected rather than posterior towards external auditory meatus.

#### **Management of the Maxillomandibular Complex** Type 1

The minimal asymmetry and deformity associated with a Type 1 HFM may be amenable to minor surgical corrections such as genioplasty (Fig. 78.22a, b). Since the occlusion may

**Fig. 78.22** (**a**, **b**) Diagrammatic representation of surgical management of Type 1 Kaban-Pruzansky (**a**) deformity with isolated genioplasty for asymmetry correction (**b**)

be normal or demonstrate minimal occlusal canting, orthognathic surgical correction may not be warranted.

In cases with minimal asymmetry where the patient is not willing to undergo a surgery of the entire maxilla-mandibular complex, it is possible to achieve facial midline symmetry by means of altering the midline chin and mandibular body orientation through an extended operation involving the basal bone of the chin and body of the mandible. It was published by Paul C Salins in 2008 [36]. The author of this chapter was happy to have learned this technique from Salins himself and greatly understood the concept of this 3D movement of genial bone along with body and ramus of the mandible to the unaffected side without altering the occlusal relationship of the maxilla or mandible.

But this technique had obvious disadvantage in the form of signifcant relapse due to large movements and requirement for multiple points of fxation.

At this juncture, the author of this chapter has designed a distractor which can be placed below the lower border of the mandible to move the genial-body-ramus unit in desired direction by incremental distraction similar to other distraction protocols. This completely eliminated the need for any plate usage, better stability without relapse and more or less excellent unlimited movement in all three directions. This is completely a basal bone distraction which can be either performed in isolation or in combination with other distractions and osteotomies of the maxilla-mandibular skeleton (Figs. 78.23a, b, 78.24a, b, and 78.25a, b).

One of the key advantages of MDO is that the bone movement produces good contour of the chin area along with fat unaffected part of the mandible, and it obviously stretches and accommodates the redundant excess submentalsubmandibular skin available to a more symmetrical position as shown in Fig. 78.26a, b.

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**Fig. 78.23** (**a**, **b**) Orthomorphic correction of defcient mandible. (**a**) Diagrammatic representation of a left sided HFM, (**b**) osteotomy design for correction of the left sided defciency

#### Type 2A

Patients with Type 2A deformities require planned presurgical orthodontic interventions for defnitive orthognathic correction (Fig. 78.27a–d).

Bimaxillary surgery is planned to achieve the following goals:

*Maxilla and midface*


#### *Mandible*


#### **Types 2B and 3**

As explained earlier, types 2B and 3 patients require reconstruction of the TMJ as the primary goal. This may be executed either as a Stage 1 correction with only maxillomandibular correction or as Stage 2 with joint reconstruction (Fig. 78.27).

Thus, although skeletal correction improves the dental occlusion and skeletal symmetry, it may accentuate the existing soft tissue discrepancy. Soft tissue augmentation should be taken up after hard tissue correction. Various methods are available such as fat transfer, microvascular free fap for adipose tissue transfer and alloplasts such as Medpore and nanogels to give shape to defcient soft tissue (Fig. 78.28a, b).

#### **78.1.7 Controversies in Surgical Management of HFM**

#### *Growth Considerations and Role of Early Mandibular Reconstruction in HFM*.

HFM has been reported as a nonprogressive disorder, i.e. proportional defciency of the face is maintained throughout the growth of the child. Indications for early reconstruction of the RCU during early childhood, especially in types 2B and 3

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**Fig. 78.24** (**a**, **b**) Pictorial view of basal bone osteotomy and orthomorphic distractor placement. (**a**) Basal view showing distractor position for orthomorphic distraction method, (**b**) frontal view of the distractor postion

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 78.25** (**a**, **b**) Indigenous distractor made and modifed, placement showed in a dry skull mandible. Note the placement of distractor on the basal bone. (**a**) frontal view of distractor placement, (**b**) basal view

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**Fig. 78.26** (**a**, **b**) Orthomorphic distraction done in a patient having hemifacial microsomia. (**a**) Pre- and (**b**) postoperative photograph showing achievement of anatomic chin and contour and mandibular asymmetry

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**Fig. 78.27** (**a**–**d**) Diagrammatic representation of surgical management of Type 2 Kaban-Pruzansky deformity (**a**). Derotation of the maxillamandibular complex by orthognathic surgery (**b** and **c**). Midline skeletal correction with a centring genioplasty (**d**)

classes, has mixed reports of success. Longitudinal studies provide evidence for stable results with early osteodistraction in mild-to-moderate skeletal deformities [20, 33, 34] (Type 1 and Type 2A). However, the role of mandibular distraction may be more relevant in severe deformities. It is also suggested that early intervention makes defnitive fnal correction easier to achieve, since the extent of deformity is reduced.

#### **78.1.8 Long-Term Results**

Long-term evaluation of growing HFM patients treated by surgical correction and distraction osteogenesis depends on two main factors: the time of intervention and the severity of the skeletal deformity. According to Hollier et al., by achieving normal mandibular dimensions at a young age, it is

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**Fig. 78.28** (**a**, **b**) Soft tissue augmentation using abdominal autologous fat transplant. (**a**) pre-surgical frontal view demonstrating severe right sided defciency in a patient with HFM, (**b**) frontal view showing soft tissue augmentation

hypothesized that the maxilla, overlying muscle and soft tissue envelope may develop along with a balanced functional matrix [19]. Proponents of mandibular distraction believe that an early intervention would prevent the secondary compensations from taking place or would unravel the compensations at the onset. This means the contralateral and ipsilateral distortions can be reduced in comparison with patients not undergoing distraction in the younger age (Figs. 78.29a, b and 78.30). Clinicians have found that early distraction can also prevent the long orthodontic decompensation phase followed by orthognathic surgery. Considering severity of deformity, the more severe deformities demonstrate less stable and favourable results when attempted early.

The indications for early skeletal correction maybe (1) compromise of airway necessitating immediate mandibular lengthening irrespective of age and (2) negative psychological impact on the child in school-going age.

In authors' experience irrespective of area and direction of distraction in the mandible or in maxilla in younger age, the following fndings were concluded in 20 years of clinical follow-up:

1. It is diffcult to predict the future growth of already distracted area of bone though claims of growth potential on distracted bone have been debated by many.


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**Fig. 78.29** (**a**, **b**) Long-term results of patient treated with mandibular distraction in childhood. (**a**) frontal photo of patient with right sided HFM at, (**b**) frontal photo of patient after 8 years follow up

10. Alloplastic prosthetic condyles should be reserved as a last resort if all other techniques fail to achieve a functionally stable total agenesis of condyles [21].

#### **78.1.9 Recent Advances**

The assessment of facial topography using non-invasive methods, such as laser surface scanners, stereophotogrammetry or ultrasonographic measurements, has been recently reported in several studies. Particularly, 3D stereophotogrammetry for the evaluation of soft tissue surface facial asymmetry has been extensively studied [36]. In distraction osteogenesis, recent advancements like automated distraction using battery-operated and hydraulic distractors have been tried. Since hemifacial microsomia involves bone augmentation in a multiplanar fashion, the advent of curvilinear and multiplanar distractors has greatly helped overcome this challenge [37, 38].

Tissue-engineered osteogenic material comprising of culture-expanded mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) can now be injected at the distraction site to ensure more predictable bone formation. Not only animal studies but also clinical trials have demonstrated that this material can effectively regenerate osseous tissue [39, 40].

#### **78.2 Treacher Collins Syndrome**

#### **78.2.1 Introduction**

Treacher Collins syndrome (TCS), also called mandibulofacial dysostosis (MFD), is an autosomal dominant disorder of craniofacial development with variable penetrance. It has a worldwide incidence of 1 in 50,000 live births (Gorlin et al. 1990) [41]. Early descriptions were given by Berry (1889), Treacher Collins (1900) and Franceschetti and Klein in 1949. Therefore, this entity is also named as Berry's syndrome and Franceschetti-Zwahlen-Klein syndrome [42, 43]. While 40% of TCS cases have a previous family history, 60% of cases could possibly arise as a result of de novo mutations (Jones et al. 1975) [44].

The TCOF1 gene plays an important role during early embryonic development for tissues derived from the frst and second branchial arches, ectodermal clefts and endodermal pouches. TCOF1 gene encodes a nuclear phosphoprotein "Treacle" that may serve as a link between rRNA gene transcription and pre-rRNA processing. TCOF1 mutation leads to abnormal neural crest cell migration or anomalies in the extracellular matrix [45]. Sulik et al. also documented excessive cell death in the maxillary and mandibular processes of the frst branchial arch and the apical ectodermal ridge of the limb bud [46]. These deductions have been made on the basis of experimental studies wherein animals were exposed to

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**Fig. 78.30** (**a, b**) Defnitive skeletal management of patient with HFM. (**a**) Preoperative Frontal photo of patient with right sided HFM at 15 years of age. He underwent mandibular distraction for correction of

teratogenic cis- or trans-retinoic acid during embryonic development. Recently, Dauwerse et al. [47] detected mutations in genes encoding subunits of RNA polymerases I and III in Treacher Collins patients.

Normally, prenatal diagnosis is recommended for families with a history of TCS using fetoscopy or ultrasound imaging [USG]. Prenatal diagnosis using either of these methods can only be performed in the second trimester of pregnancy (approximately 18 weeks). Due to the late nature of the diagnosis, termination of pregnancy can be a particularly traumatic procedure. Imaging with USG has improved immensely in recent years [e.g. 3D sonography], allowing non-invasive prenatal diagnosis to be made. However, mild cases of TCS are still diffcult to diagnose. Genetic counselling is highly recommended for affected individuals and their families for prevention of further affected child birth.

asymmetry followed by second stage Bi maxillary orthognathic surgery at 18 years of age (Fig. 78.7a). (**b**) Stable skeletal results after a 7 year followup when patient is 25 years of age

#### **78.2.2 Clinical Features and Presentation**

The complete spectrum of features which can be present are explained in the table below [48] (Table 78.7).

A case of Treacher Collins syndrome in a 13-year-old female with the following features (Fig. 78.31a, b):


• Ears: Malformation of the external, middle and inner ear, with low implantation of the auricle which is common. The pinnae are often crumpled and misplaced towards the angle of the mandible. Bat-fan ears, deafness, microtia, extra ear tags and blind fstulas [which may occur anywhere between the tragus and the angle of the mouth] are the other common fndings.

#### **Table 78.7** Clinical features of TCS



#### **78.2.3 Imaging for TCS**

The conventional OPG and the lateral and frontal cephalometric image are pivotal in diagnosing TCS along with clinical correlation. The OPG helps identify the following: hypoplastic condyle with a short condylar neck, absent articular eminence, shortened ramus-condyle unit and severely hypoplastic coronoid process (Figs. 78.33 and 78.34). The lateral cephalogram shows a severely retrognathic mandible with microgenia, clockwise-rotated maxillomandibular complex and a reduced posterior airway space. However, threedimensional computed tomography [3DCT] is the gold standard in diagnosis as well as treatment planning (Fig. 78.35a–c). The features that are remarkably seen on the 3DCT are hypoplasia of the orbito-zygomatic complex, poorly developed lateral orbital and supraorbital ridges, mandibular hypoplasia and reduced overall facial width. The orbits are hyper-teloric and the infraorbital foramen is usu-

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 78.32** (**a–e**)Intraoral pictures of the same patient in Fig. 78.30 showing operated cleft palate, mixed dentition stage with severe crowding. (**a**–**c**) frontal and lateral intra-oral dental views, (**d**) maxillary occlusal and (**e**) mandibular occlusal views

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 78.33** Lateral cephalogram of the same patient in Fig. 78.31 showing reduced posterior airway space, micrognathia and microgenia

ally absent. The paranasal sinuses are often small and may be completely absent. Furthermore, the mastoids are not pneumatized and are frequently sclerotic. The cranial base is also progressively kyphotic [48]. Lastly, these patients require

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**Fig. 78.34** Orthopantomogram of the same patient in Fig. 78.31 showing hypoplastic ramus-condyle unit

long-term follow-up in order to evaluate the effects of mandibular growth, airway dimensions, degree of surgical relapse and the need for additional surgical intervention.

#### **78.2.4 Proposed Classifcation**

A classifcation system of the orbito-zygomatic skeletal deformities seen in TCS has been proposed by Nikkah D et al. The classifcation is designed to characterize the degree of deformity and as a guide to the reconstructive planning [49]. Treatment planning becomes complex as TCS can have a variable presentation with respect to the severity of the hypoplasia/dysplasia of the skeletal and soft

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 78.35** (**a**–**c**) 3DCT view of TCS patient showing hypoplasia of orbito-zygomatic complex. (**a**) Right lateral view demosntrating type 2b deformity, (**b**) frontal view showing type 2b deformity on the right and type 3 deformity on the left, (**c**) left lateral view showing type 3 deformity

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 78.36** (**a**, **b**) Type 1: Patients have the entire orbito-zygomatic complex present but the region is dysplastic and hypoplastic

tissue elements, shape and position of the affected structures and resulting functional deformity. Thus, the challenges faced in treating TCS are similar to those faced in treating HFM.

#### **78.2.4.1 Methods**


©Association of Oral and Maxillofacial Surgeons of India

There is not always a symmetrical classifcation as 25% of the TCS demonstrated asymmetry.

#### **78.2.4.2 Classifcation of Temporomandibular Joint and Mandibular Malformation**

The Kaban and Pruzansky classifcation system for the degree of TMJ-mandibular malformation in HFM is applicable to TCS patients as well [13, 26]. This classifcation is useful in defning the anomalies and directing reconstruction similar to HFM patients.

#### **78.2.5 Diferential Diagnosis**

Differential diagnosis of TCS includes acrofacial dysostosis (Nager and Miller syndromes) and oculo-auriculo-vertebral spectrum (hemifacial microsomia and Goldenhar syndrome).

Nager syndrome has facial features similar to that of TCS. In addition, the thumb[s] may be hypoplastic, aplastic or duplicated, and there may be fusion of the radius and ulna. Miller syndrome also has features similar to TCS. Ectropion or outturning of the lower lids is an additional diagnostic feature. Clefting of the lip and palate is more common in this syndrome than in TCS [50]. HFM primarily affects development of the ear, mouth and mandible. Goldenhar syndrome has a spectrum of deformities that include those of HFM in addition to vertebral abnormalities and epibulbar dermoids [51].

#### **78.2.6 Treatment**

Though there have been immense medical advances in terms of in utero surgery, stem cell therapy and genetic manipulation, there is currently no treatment for TCS in utero. Treatment is performed postnatally according to the nature of the deformity and severity of functional disturbance [52].

The following issues are present in case of TCS:


These issues can challenge clinicians from birth to adulthood as concerns vary from aesthetic to functional in nature. Thus, a multidisciplinary approach is indispensable for achieving optimal outcomes.

#### **78.2.6.1 Multidisciplinary Management: Team Members Necessary from Birth to Adult Stage**


#### **78.2.6.2 Airway Management**

Syndromic patients [e.g. TCS] with micrognathia suffer from OSA frequently due to narrowing of the upper airway [53]. Despite respiratory effort, partial or complete obstruction of the upper takes place, leading to frequent episodes of oxygen desaturation and sleep disruption. In the long term, OSA can harm an individual's physical and mental health, as has been documented recently in the literature [54].

Respiratory compromise is due to two reasons:


Earlier, long-term tracheostomy was the only solution available for severe cases of infantile OSA. However, longterm tracheostomies are commonly associated with morbidities like tracheomalacia, chronic bronchitis, throat tightness and dislocation of the tracheostomy tube [55] (Fig. 78.38a, b). Today, distraction osteogenesis [DO] has become the favoured treatment method for TCS patients with OSA. Mandibular advancement by means of DO helps in increasing the posterior airway space, thus relieving the symptoms of OSA and preventing severe respiratory distress [56]. Due to the unique mandibular and oropharyngeal anat-

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**Fig. 78.38** (**a**, **b**) Photograph of a 4-year-old male with TCS. Patient had history of hospitalization due to respiratory distress. Tracheostomy tube in situ since 7 months of age

©Association of Oral and Maxillofacial Surgeons of India

omy of TCS patients, a fbre-optic-assisted intubation method similar to that described by Ellis et al. can be successfully used [57].

Paediatric mandibular advancement was initially performed using bilateral external distractors which are advantageous because of their ease of use, manipulation and versatility [ 58]. However, external devices also create aesthetic [e.g. scarring] and social problems. Another important point to be noted is that retention period of such devices is reduced and an increased relapse rate is seen compared to internal distractor devices [59]. If the child is extremely uncooperative and parents are unable to maintain and monitor the external distractors, an internal distractor should be used (Fig. 78.39a, b).

Recently, paediatric mandibular distraction for OSA has been discouraged in many centres around the world due to concern of permanently damaging the teeth buds. Instead, tongue lip adhesion (TLA) has been popularized by many centres instead of DO as it has signifcantly lower morbidity. After the airway improves, better feeding and weight gain are expected and cleft palate closure is done. Subsequently, TLA release can be attempted [60]. In comparison to DO, the TLA needs stricter postoperative care in intensive setup as feeding and breathing need to be assessed regularly for a week at the minimum.

#### **78.2.6.3 Feeding Problem**

The abnormal or hypoplastic craniofacial issues in TCS can sometimes produce severe feeding problem for infants, leading to weight loss and failure to thrive. Most feeding problems relate to cleft lip and palate, retrognathic jaws and airway problems. Ideally, a craniofacial feeding management team should guide the parents regarding position of feeding, type of nutrition and dietary plan for such children.

Position (holding the baby upright or supporting the cheek and jaw while feeding) is important to avoid aspiration. It is also preferable to do a video-fuoroscopic swallow study (VFSS) to understand the swallowing pattern of the patient and its coordination with breathing [61].

Primary palatoplasty for closure of the cleft palate should be done once the patient gains weight, to assist in normalizing the swallowing pattern without nasal regurgitation.

#### **78.2.6.4 Brain and Psychological Development in TCS**

Individuals with TCS have a tendency towards a shorter stature, at least early in life. Intelligence is usually unaffected, but brain and behavioural anomalies such as microcephaly and psychomotor delay have been occasionally reported as part of the condition. Additionally, the facial deformity of this syndrome may affect psychosocial development, school adjustment and other milestones. A psychologist or social worker should be made available for evaluation and counselling if needed.

In the Indian scenario, poor parental awareness, lack of medical advice, social taboos and feeding diffculties lead to failure to thrive among TCS infants and children belonging to lower socio-economic classes. Psychological stress during schooling [e.g. marked out as different by peers] is one of the more challenging issues to be addressed throughout the life of the patient.

#### **78.2.6.5 Management of Cleft Palate**

Isolated cleft of the soft palate is the most common form of cleft in TCS. Complete cleft palate up to the alveolus may also be seen. Closure of the soft palate is routinely done at the end of 1 year. Meticulous dissection and suturing of soft palate muscles can produce excellent results, nearing to that of a normal palate. Postoperative maintenance of oral hygiene is necessary and can become challenging in these children for fear of aspiration. Velopharyngeal insuffciency [VPI] is a common issue in these children. VPI can be corrected secondarily with intra-velar palatoplasties or buccal advancement faps for velar lengthening.

#### **78.2.6.6 Ophthalmological, Auricular and Hearing Issues**

#### **Ophthalmological Issues**

Eye anomalies include aberrations in the extraocular muscle function, corneal exposure diffculties and visual acuity. Ophthalmologic issues may include vision loss (37%), amblyopia (33%), refractive errors (58%), anisometropia (17%) and strabismus (37%). A thorough paediatric ophthalmological assessment should be done to establish proper management.

#### **Hearing Issues**

A 3D CT of the petrous temporal bones should be done to accurately assess the external auditory canal and middle and inner ear anatomy. TCS patients with microtia can have congenital aural atresia and extremely narrow canals, leading to signifcant conductive hearing loss as the bone blocks passage of sounds to tympanic area and middle ear. Furthermore, exfoliated skin cells and ear wax cannot drain out, leading to otitis media and occasionally form cholesteatoma. Despite hearing loss, these children tend to grow normally. However, the chances of developmental cognitive defcits are not uncommon.

#### **Microtia Correction**

Microtia ear correction can be done when the patient is around 6 to 7 years old, an age at which external ear development is complete. The most preferred way of auricle reconstruction is the use of autogenous rib cartilage, in a staged manner. The rib cartilage is harvested from the sixth to the ninth rib. The sixth and seventh rib cartilage are utilized to form the base of the framework. The triangular fossa and scapha are carved in the superior portion of the previously created cartilaginous base. The eighth rib cartilage is then carved to replicate the helical rim. The carved cartilage is then inserted under the skin in the region of the missing ear, with or without skin expansion (Fig. 78.19).

Bone-conduction hearing aids such as the bone-anchored hearing appliance (BAHA) or a middle ear implantable prosthetic device can signifcantly improve hearing in these patients.

#### **78.2.6.7 Nasal Issues**

Nasal deformities can be classifed as external or internal in nature. Commonly seen external nasal deformities are the dorsal hump (73%), external deviation (≤55%), bifd or bulbous nasal tip (55%) and columellar septal luxation (55%). Commonly seen internal nasal deformities are nasal obstructions due to septal deviation and presence of spurs. Due to presence of the above structural deformities, functional problems, e.g. snoring and impaired phonation, are commonly present in these patients.

A detailed physical examination along with nasal endoscopy and 3D CT of the nasal and paranasal regions can help identify all the deformities present. The commonly performed procedures that should be paid attention to are dorsal hump reduction, correction of the deviated external osseous deformity, septoplasty and tip plasty.

#### **78.2.6.8 Dentoalveolar Issues and Orthodontic Alignment**


#### **78.2.6.9 Management of the Adult TCS Patient**

#### **Clinical and Cephalometric Features**

The adult patient with TCS has a convex facial profle due to severe mandibular retrognathia. However, the horizontal projection of the maxilla to the cranial base remains normal. Over the growth period, the facial convexity angle remains relatively constant, thus confrming that the facial profle morphology of the infant with TCS remains similar to that of the adult.

©Association of Oral and Maxillofacial Surgeons of India

The total facial height is often excessive, with a normal upper facial height. This is due to combination of anterior open-bite malocclusion, mandibular retrognathism and chin dysplasia. Hypoplasia of the orbito-zygomatic complex is a characteristic feature. These hypoplastic facial skeletal features have variable effects on the TMJ, masticatory function and facial soft tissues and expressions.

Both the maxilla and mandible are rotated in a counterclockwise rotation. Thus, the maxillary and mandibular plane angles are excessively steep. Clinically, this translates to a shorter posterior facial height in TCS patients.

The mandible size is evidently decreased in both the ramus height and the body length. The gonial angle is obtuse with anti-gonial notching. The steepness due to clockwise rotation of the maxillomandibular complex along with the anterior and posterior vertical height disproportions and severe horizontal defciency is refected in the A-point-to-Bpoint discrepancy. All of these cephalometric fndings explain the clinical facial dysmorphology.

Incidence of cleft palate with or without cleft lip (and choanal atresia of the nasal cavity) is variable. Dental anomalies are present in 60% of individuals such as tooth agenesis enamel, opacities and ectopic eruption of the maxillary frst molars.

#### **78.2.6.10 Surgical Management of the Orbitozygomatic Region**

*Treatment of the skeletal defect in the orbito-zygomatic region* varies according to the severity of the defect. The following classifcation categorizes the deformities according to severity and their treatment. Since this region attains growth by age of 9, most surgeons postpone defnitive reconstruction up to this age.

*Type 1 defects*: The orbito-zygomatic complex is dysplastic and hypoplastic. Type 1 represents the mildest form of the defect and can be easily treated by autologous fat, either by liposuction and injection or dermis fat graft [65]. The merit of autologous fat grafting is that it is repeatable with minimal donor site morbidity and can be done before growth completion. It is ideal for growing children who are psychologically affected due to a poor facial appearance. The disadvantage of this technique is that it may have to be performed repeatedly to maintain the volume of correction.

Fat transfer can be used alone for correction of minor defects. It has more of an adjunctive role in severe defects after wherein hard tissue augmentation is the preferred intervention.

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**Fig. 78.41** (**a**, **b**) Extraoral profle view showing marked improvement in the lower third of the face. (**a**) Pre-surgical profle photo showing retrogenia (Fig. 78.31a1), (**b**) post-surgical profle photo after a double sliding genioplasty, showing good chin prominence

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 78.42** (**a**–**c**) Intraoperative view of double sliding genioplasty done for the same patient as in Fig. 78.41. (**a**) Surgical exposure of the genium, (**b**) osteotomy design marked on the chin and (**c**) completion of genioplasty with fxation (also see Figs. 68.32 and 68.33 for use of double sliding genioplasty in other clinical situations)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 78.43** (**a**–**f**) Case of TCS who underwent early osteodistraction. (**a**, **b**) Pre-operative frontal and profle photos, (**c**, **d**) Frontal and profle photos post distraction with bilateral uni-directional distractors, (**e**, **f**) Frontal and profle views after fve years follow-up

*Type 2 defects:* Defect consists of hypoplastic zygomatic body with a reduced zygomatic temporal process and a dysplastic or absent lateral orbital wall. This class of defect usually requires surgery to address the bony defciency. Studies have established that a malar osteotomy offers better contour as compared to onlay bone autografting [66]. Though the malar osteotomy is aimed at correcting the width of the midface, it is diffcult to augment anteroposterior projection by osteotomy only. It should be noted that this defect is characterized by a defcient vertical dimension as well. Thus, a zygomatic osteotomy is preferably combined with an onlay graft. The Mommaerts zygomatic osteotomy is favoured in some units because it does not alter orbital dimensions. Alloplastic materials [e.g. Medpore] can be very effective alternatives to the traditional onlays [67].

#### **Types 3 and 4**

The defects range from severe hypoplasia/dysplasia to complete absence of orbito-zygomatic bony complex. Patients belonging to these groups require bony augmentation. In adults, alloplastic augmentation with patient-specifc implants can be considered as they provide optimal results.

In general, the zygomatico-maxillary-orbital bone complex can be reconstructed using an autologous free bone or regional pedicle graft. Non-vascularized autologous bone grafting for larger defects is increasingly prone to loss of graft due to infection and resorption if not fully covered by surrounding soft tissue. Studies have established that resorption occurs due to reduced vascularity and increased functional loads on the graft. Therefore, it is prudent to line the bone grafts by soft tissue on its inner side in the proximity of maxillary sinus and nasal cavity [68].

1805

Calvarial bone grafts have been used for reconstruction of midface in various craniofacial deformities. Fullthickness calvarial grafting outcomes are more stable in the long term due to the dense cortical nature of the graft (Fig. 78.44a, b). Studies [69] have also established that dense membranous bone grafts [e.g. calvarial] are more effective than endochondral grafts [e.g. iliac crest] in the craniofacial skeleton. Calvarial bone grafts have become popular because of their low resorption rates and minimal donor site morbidity for orbito-zygomatic complex reconstruction [70].

#### **78.3 Conclusion**

Hemifacial microsomia and Treacher Collins syndrome are both congenital craniofacial anomalies that negatively impact the physiological and psychological wellbeing of an individual [71]. Due to multidimensional nature of the deformity, a multidisciplinary holistic approach is required with proper guidance and counselling of the patients at every level of treatment. However, with the advances in regenerative sciences and genetic engineering, diagnosis and management of such congenital deformities is becoming less challenging. Disclosure Authors have no fnancial conficts to disclose.

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**Fig. 78.44** Skeletal correction for TCS. (**a)** Calvarial graft harvest for recsontruction of zygoma, (**b)** graft in place, (**c)** osteotomy design for orthognathic correction with bimaxillary surgery and genioplsty, (**d)** diagram showing post orthognathic fnal correction

#### **78.4 Case Scenarios**

## **Case 1: Treacher Collins Syndrome**

(Fig. 78.43a–f)

Case of TCS who underwent early osteodistraction. Note the mandibular advancement using bilateral unidirectional distractors. Follow-up after 5 years. Patient is currently undergoing orthodontic treatment.

**Case 2: Hemifacial Microsomia** (Figs. 78.45a–e, 78.46a–c, 78.47a, b, 78.48a–c, 78.49a–c, 78.50a, b, 78.51, 78.52a–d, 78.53a, b)

Case of a 20-year-old girl having HFM, undergoing osteotomy for asymmetry correction. Preoperative photographs, radiographs and CT scans showing the extent of asymmetry. Pre-surgical orthodontics for levelling and alignment. Virtual planning to fabricate CAD-CAM splint. Final postoperative

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**Fig. 78.45** (**a**–**e**) Preoperative views of a female patient with facial asymmetry and deviation towards the left side

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**Fig. 78.46** (**a**–**c**) Intraoral view showing malocclusion, crowding and midline deviation

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**Fig. 78.47** (**a**, **b**) Preoperative (**a)** lateral cephalogram and (**b**) OPG showing Class II skeletal profle with left-sided TMJ deformity

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**Fig. 78.48** (**a**–**c**) Preoperative CT scans showing TMJ deformity on the left side

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**Fig. 78.49** (**a**–**c**) Pre-surgical intermediate orthodontics treatment for alignment and levelling

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**Fig. 78.50** (**a**, **b**) Virtual planning using 3D photogrammetry. (**a**) soft tissue reconstruction from the CT data, (**b**) superimposition of the patients photograph on the CT model

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 78.53** (**a, b)** Postoperative (**a**) lateral cephalogram and (**b)** OPG showing correction of maxillomandibular relation. Refer to Fig. 78.47 for pre-operative xrays

photographs and radiographs showing correction of asymmetry.

#### **References**


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## **Modern Management of Craniosynostosis**

David Koppel and Jaime Grant

# **79**

#### **79.1 Introduction**

The different presentations of craniosynostosis form the majority of the workload of craniofacial services, and it is important to note that the surgical interventions only form a small part of the overall management of this vulnerable group of patients and their families.

#### **79.1.1 Defnition**

Craniosynostosis is defned as the premature fusion of one or more of the cranial sutures. This premature fusion can either be an isolated disorder (e.g. sagittal synostosis) or form part of a syndrome (e.g. Apert syndrome). In many cases the resultant head shape is typical of the involved suture such that the Greek/Latin descriptive terms are used synonymously with the description of the affected suture. For example scaphocephaly (boat-shaped head) is used to describe sagittal synostosis; however this approach can lead to confusion as can be seen in the use of the term plagiocephaly (fat head) which may refer to a unicoronal synostosis but also can be used in unilateral lambdoid synostosis, skull base torsion, the deformity resulting from torticollis and positional skull deformities. For this reason it is probably best to avoid the Latin/Greek descriptive terms and identify the affected suture(s) by name.

The majority of craniosynostoses are primary in nature and congenital; however a small proportion are termed secondary—caused by another pathology, usually resulting in reduced brain growth as seen in microcephaly or post-shunting.

#### **79.1.2 Aetiology**

#### **79.1.2.1 Primary Craniosynostosis**

In the majority of cases, no cause for the synostosis is identifed, but in an increasing proportion (currently about 25%), a mutation is identifed. A signifcant proportion of these mutations are related to six genes FGFR2, FGFR3, TWIST1, EFNB1, TCF12 and ERF, however there is an increasing frequency of additional mutations being identifed by more complex genetic analysis.

The incidence of identifying a mutation is much higher in syndromic craniosynostosis cases (69%), but the rate of mutation identifcation in the non-syndromic cases is increasing (currently 5%) particularly in the bicoronal, multisuture and unicoronal (in decreasing frequency) [1].

These genetic advances have assisted in the diagnosis of these conditions and infuence the genetic counselling but have yet to impact on the management of the resultant problems related to the premature suture closure. As the mechanisms of sutural control and homeostasis are elucidated, novel therapies may be introduced.

#### **79.1.2.2 Secondary Craniosynostosis**

Microcephaly and babies who have been shunted as well as other systemic conditions such as sickle cell disease, thalassaemia and rickets can lead to synostosis usually affecting all the sutures. In cases of microcephaly, it is important to differentiate between a primary pansynostosis resulting in a small head often with raised intracranial pressure from a secondary synostosis with normal intracranial pressure [2].

D. Koppel (\*)

Consultant Craniofacial/Oral & Maxillofacial Surgeon, Clinical Director Surgery & Gastroenterology, Clinical Lead Scottish National Craniofacial Service for Children and Young People, Royal Hospital for Children, Glasgow, UK e-mail: davidkoppel@nhs.net

J. Grant Craniofacial Fellow, Birmingham Children's Hospital, Glasgow, UK e-mail: jaimegrant@nhs.net

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1813

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_79

#### **79.1.3 Epidemiology**

The incidence of craniosynostosis ranges from 1 in 1400 to 1 in 2100 live births worldwide with a slight male preponderance.

The different types of craniosynostosis occur in the following proportions:


utility and is in fact misleading—the deformity as a result of a unicoronal synostosis is extremely complex and as more is understood about the genetic basis the more complex the condition becomes.

In terms of utility, the craniosynostosis is best classifed by the suture(s) involved and whether this is associated with a syndrome (i.e. other abnormalities). See Table 79.1 and Illustrations 79.1, 79.2, 79.3, 79.4, 79.5, 79.6 and 79.7. The condition can be further defned by the genetic abnormalities. In general the syndromic craniosynostosis cases tend to be more severe and have a greater incidence of complicating features.

#### **79.2 Management**

**79.1.4 Classifcation**

The classifcation of craniosynostosis has, in recent years, changed; the previously utilised terminology of simple and complex, referring to single-suture and multiple suture abnormalities, respectively, has been abandoned. It has little The care of babies and children with craniosynostosis is best delivered in a centre with access to a full multidisciplinary team. This team involves the core specialities of paediatric neurosurgery and craniofacial surgery (either OMFS or plastics based) as well as support from paediatricians, neonatologists, geneticists, respiratory specialists, ophthalmologists and ENT surgeons. The input from specialist nurses and psychologists is vital [4].



©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Illustration 79.6** (**a**, **b**) Pansynostosis causing turricephaly or oxycephaly

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Table 79.2** Treatment options in infancy for complex synostosis problems


#### **79.2.1 Prenatal Diagnosis**

The use of high-defnition prenatal ultrasound has increased the early diagnosis of both hydrocephalus and craniosynostosis [5]. This facilitates the preparation of parents for the birth of a child who is likely to have additional medical, surgical and emotional needs. In these circumstances parents getting to know the craniofacial team and being better informed of the potential problems often makes supporting them much easier.

#### **79.2.2 Perinatal Care** (Table 7.2)

In the perinatal period, care is directed at optimising the airway, ensuring the child is well oxygenated, preventing corneal damage (ocular protection) and confrming the diagnosis. In the majority of single-suture abnormalities, there are often no issues that prompt early intervention; however in the complex syndromic cases, this is not the case. Airway problems due to severe midface retrusion; breathing disturbance due to central problems, often due to posterior fossa crowding and Chiari malformation; corneal exposure secondary to midface and brow retrusion; and associated non-craniofacial anomalies prompt more urgent interventions. The necessity for such interventions is greatest in the syndromic conditions such as Apert, Pfeiffer, Crouzon and Carpenter syndromes. In cases where there is signifcant midface retrusion, there may also be feeding diffculties [6].

In the severe cases, initial care is supportive. The airway should be assessed and intervention initiated if necessary. It is important to assess the oxygen saturation and the work of breathing and correlate these fndings with formal blood gas measurements. This assessment can be augmented with a formal sleep study, and on occasion simultaneous measurement of intracranial pressure may be helpful. Airway support can range from positional nursing, the use of a nasopharyngeal airway, intubation and in some cases tracheostomy. As part of this assessment, when the airway is an issue of concern, consideration should be given to performing a CT scan, and this will be useful to look at cranial anatomy but also the nasal anatomy, particularly to exclude choanal atresia. In assessing the airway, babies often manage satisfactorily but may suddenly decompensate with a minor upper respiratory tract infection or whilst feeding [6].

Surgical intervention in this period is only undertaken when the airway is such that no simple measures are able to overcome the symptoms; often a period of intubation is helpful to allow for a more thorough assessment rather than rushing to either tracheostomy or a monobloc fronto-facial advance.

During this period parents and family members have to come to terms with the often unexpected consequences of having a child with additional needs and medical interventions. Early and ongoing support needs to be delivered; this can and should be through multiple avenues. Many such children are born in institutions with little or no experience of the condition(s), and this professional unfamiliarity often adds to parental anxiety. For these reasons early contact with a dedicated craniofacial team is invaluable. Specialist nurses, psychologists and support groups can often ease the stress of this diffcult time [7].

#### **79.2.3 Care in Infancy**

The management of craniosynostosis in infancy is primarily aimed at addressing the primary consequences of the premature suture closure as well as dealing with the associated problems.

The management of the synostosis has, over the years, evolved considerably and in some respect completed a complete circle. The treatment is aimed at ensuring cranial volume is satisfactory to ensure that there is no elevation of ICP (in the absence of hydrocephalus) as well as attempting to normalise the head shape. The normalisation of head shape is done to maximise the chances of a normal head shape at the completion of growth. Initial treatment introduced in the second half of the last century involved a procedure known as suturectomy [8]. The principle of this was to excise the pathological, prematurely fused suture with the idea that removal of the pathology would allow the skull to continue to grow into a normal shape possibly aided by the continued growth of the brain. This was found to be partially effective especially when done before the age of 18 months [9]. It was however noted that in many cases re-fusion of the suture occurred and a number of surgeons began wrapping the bone edges on either side of the resected suture with silicone edging in an attempt to minimise the chances of re-fusion. Unfortunately this approach did not prevent re-fusion, and this often occurred on the dural side of the silicone edging. In pansynostosis cases the sutures were excised and the remainder of the skull was morselised [9]. These simple techniques have been superseded with more complex reconstructive procedures involving suturectomy and remodelling. (See case series examples (Figs. 79.2, 79.3, 79.4 and 79.5). When the coronal sutures are involved, either unilaterally or bilaterally, and/or the metopic sutures, the mainstay of treatment is a fronto-orbital advancement, with remodelling of the affected bones. When the sagittal suture is involved, the affected suture is excised and the remaining skull remodelled. The extent of remodelling varies from case to case but can involve addressing the frontal bossing, bitemporal narrowing and the occipital bullet [4]. These procedures involve extensive exposure and blood loss with their attendant risks, and for these reasons there has been a move to attempt to correct these abnormalities with less invasive procedures. These less invasive approaches utilise endoscopic suturectomy coupled with active postoperative helmet therapy to mould and harness the ongoing brain and hence skull growth [10]; another approach has used a minimal access suturectomy and specially designed springs to actively separate the affected suture edges [11]. A further technique, particularly in bicoronal or pansynostosis cases, is to utilise distraction osteogenesis; a craniotomy of the occipital bone is performed, and two or three distraction devices are applied; these are then activated over a period of 2–3 weeks, expanding the skull volume and in many cases improving the posterior fossa crowding seen in such cases. For reasons not fully understood, this technique often leads to a signifcant improvement in the contour of the frontal bones [12].

In terms of timing of surgery, there is considerable variation between different centres. In general elective (not motivated by functional concerns), suturectomy and skull remodelling procedures are performed between the ages of 5 months and 2½ years. The younger the patient, the greater the contribution of normal brain growth in normalising head shape; however the drawback of earlier surgery is the fragility of the skull bones and most importantly the risks of complications—particularly excessive blood loss [13].

During this period patients are generally followed up to monitor for signs of raised intracranial pressure, obstructive sleep apnoea (OSA) and evidence of a signifcant change in the rate of head growth as indicated by head circumference. Discrepancies between the plots on the growth charts (Fig. 79.1a, b) for length, weight and head circumference as well as plots crossing the centile lines should prompt further investigation.

**b**

**Fig. 79.1** (continued)

#### 79 Modern Management of Craniosynostosis

**Fig. 79.2** (2.1–2.9) Case series of sagittal synostosis. (2.1–2.4) Preoperative facial views of patient with sagittal synostosis aged 13 weeks. Note elongated A-P dimension and bitemporal narrowing with

prominent forehead and occiput. (2.5–2.7) Postoperative facial views of patient with sagittal synostosis after full calvarial remodelling. (2.8 and 2.9) Preoperative CT scan of the same patient with sagittal synostosis

**Fig. 79.2** (continued)

©Association of Oral and Maxillofacial Surgeons of India

#### **Fig. 79.2** (continued)

Elevated ICP manifests as distressed behaviour, inconsolable crying and headbanging with symptoms being worse at night. When symptoms are combined with papilloedema, urgent intervention is indicated. The absence of papilloedema does not exclude raised ICP, but its presence is of signifcance. In cases of doubt, formal ICP monitoring can be undertaken. In established cases the use of an indwelling telemetric ICP measurement device may be helpful [14].

Formal ophthalmological assessment should be undertaken and appropriate intervention initiated. Regular assessments are necessary to identify deterioration, particularly to identify corneal exposure and avoid the development of amblyopia.

Routine computerised tomography (CT) cross-sectional imaging is not indicated, and the diagnosis can, in the vast majority of cases, be made on clinical fndings alone. In cases where the diagnosis is in doubt or there is the suspicion that there may be posterior fossa crowding, Chiari malformation or craniocervical abnormalities, a CT is indicated. Magnetic resonance imaging (MRI) is indicated to investigate the brain for structural abnormalities. The objective with this very conservative approach to imaging is to minimise the ionising radiation exposure, which has been demonstrated to adversely affect brain development and damage the developing eye [15].

Obstructive sleep apnoea can manifest as noisy snoring, characteristically crescendoing to a maximum followed by a period of silence, representing the apnoeic period with a cyclical restart, or a failure to thrive coupled with daytime tiredness. If OSA is suspected, an initial overnight pulse oximetry study can be undertaken, and if this proves to be suggestive of OSA, a full polysomnogram sleep study should be performed. This can be combined with formal ICP monitoring should there be any concerns about raised ICP. The active management of established OSA requires intervention from the multidisciplinary team, and the respiratory/ENT specialist input is paramount. It is important to establish the causes of sleep disorder and the level(s) of airway obstruction so that the most appropriate intervention(s) can be employed. Further investigations might involve microlaryngoscopy to exclude tracheal abnormalities. Imaging with CT is useful, and interventions should be stepwise with consideration being given to tonsillectomy and adenoidectomy [16].

In the majority of cases of non-syndromic single-suture abnormalities, a single intervention for the surgical correction of the head shape is the norm [4].Whilst there is considerable variation between different units regarding

**Fig. 79.3** (3.1–3.17) Case series of metopic synostosis. (3.1–3.3) Preoperative facial views of patient with metopic synostosis, age 23 months (late presentation), note pointed brow, triangular-shaped skull and hypertelorism. (3.4–3.6) Preoperative CT scan of the same patient with metopic synostosis—note it is not our usual practice to obtain preoperative CT in metopic synostosis; however this was taken due to the subtle (and late) presentation. (3.7–3.14) Intraoperative views of fronto-orbital remodelling. (3.7) Frontal bar after removal prior to remodelling. (3.8) Frontal bar and fontal bones after removal prior to remodelling. (3.9, 3.10) Frontal bar after remodelling with midline graft to correct hypotelorism. (3.11) Frontal bone osteotomised ready for remodelling. (3.12–3.14) Final views after fxation—frontoorbital remodelling or anterior two-thirds remodelling. Note use of absorbable plates in load−/tension-bearing areas and absorbable sutures or stainless steel wires in less critical regions. Bone dust and bone dust putty (fbrin sealant mixed with bone dust) are used in resultant bone defects to encourage ossifcation. (3.15–3.17) Postoperative facial views of patient with metopic synostosis

**Fig. 79.3** (continued)

**Fig. 79.3** (continued)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 79.3** (continued)

**Fig. 79.4** (4.1–4.12) Case series of unicoronal synostosis. (4.1–4.4) Preoperative facial views of patient with unicoronal synostosis, patient aged 31 weeks—left unicoronal synostosis—fattened left brow anterior plagiocephaly when viewed from above and ridging of the involved left coronal suture. (4.5–4.9) Intraoperative views of asymmetric fronto-orbital advance. (4.5) Precraniotomy planning—note the fused

left coronal suture. (4.6–4.9) After fxation of the osteotomised segments—asymmetric fronto-orbital advancement; note onlay bone graft to left supraorbital region, fxation with absorbable plates and pins as well as absorbable sutures. (4.10–4.12) Postoperative facial views of patient with unicoronal synostosis

**Fig. 79.4** (continued)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 79.4** (continued)

**Fig. 79.5** (5.1–5.13) Case series of Crouzon syndrome. (5.1 and 5.2) Patient with Crouzon syndrome after initial calvarial remodelling aged 34 weeks. (5.3 and 5.4) Preoperative facial views of same patient aged 5 with Crouzon's type facies. (5.5–5.7) Postoperative facial views after Le Fort III distraction osteotomies and static fronto-orbital advance with the rigid external distractor (RED frame) and internal distractors in place (day 1 post-op). The use of the internal distractors allows for the early removal of the external device after the active distraction period, acting as fxation devices for the retention period. (5.8–5.9) Final postoperative result immediately after RED frame distractor removal. (5.10–5.11) Late postoperative result following internal distractor removal. (5.12 and 5.13) Pre- and mid-distraction CT images of Le Fort III distraction and static fronto-orbital advance. Note internal distractors engaging zygoma (pushing Le fort III and external RED frame pulling midface). It is not our usual practice to obtain a CT mid treatment, but this was carried out due to concerns around a possible CSF leak. The static fronto-orbital advance is secured with absorbable, radiolucent, plates, but the multiple pin holes are visible

**Fig. 79.5** (continued)

**Fig. 79.5** (continued)

1834

©Association of Oral and Maxillofacial Surgeons of India

#### **Fig. 79.5** (continued)

timing and actual intervention, the Glasgow craniofacial service protocol is outlined in Table 79.3. See also Table 79.4 for an outline of the surgical procedures commonly carried out and the case series (Figs. 79.2, 79.3, 79.4 and 79.5) for an overview of treatment outcomes.

In the management of the syndromic cases, the treatment has to be more fexible and problem driven. There is considerable variation in the severity and comorbidities in this group of patients. Overall the aim is to minimise the number of surgical interventions; however re-synostosis, systemic problems, corneal exposure, airway obstruction and raised ICP are much more common in the group [14]. In the absence of additional pressing clinical issues, the syndromic synostosis cases can be managed as the non-syndromic cases in terms of the timing and extent of skull surgery.

#### **79.2.4 Management in Early Childhood (3–8 Years)**

In this period the management is primarily of observation. The non-syndromic cases are followed up 6 weeks, 6 months and 1 year post-skull vault surgery with growth, particularly head circumference, development and vision being moni-

**Table 79.3** Glasgow protocol for the management of non-syndromic synostosis


In the presence of elevated ICP

tored. A fnal review is usually undertaken immediately prior to the child starting school. Some units have a much longer follow-up period; however we reserve longer follow-up for the small proportion of patients who encounter ongoing development problems or symptoms. This protocol should be modifed if there is a less well-developed communitybased health surveillance programme.

The syndromic cases are followed up more closely with a minimum of annual reviews. In addition to the parameters noted above, the development of OSA may be insidious, and therefore at every review this should be asked about specifcally. Towards the end of this period, consideration can be given to performing either a midface advancement or hypertelorism correction. This decision should be primarily driven by clinical problems rather than purely aesthetics, though teasing, bullying and psychological issues can, and should, play a role in decision-making. The input of child psychologists is often very helpful in developing a treatment plan and choosing the optimal timing [17].

During this period it is also important to monitor dental development and try to optimise routine dental care. In addition, at some time the patient should be referred for a full genetic consultation, though the timing of this can be determined by the needs and desires of the family. Throughout the care of the patient development, psychological, educational, physical and speech and language development should be monitored and intervention initiated when necessary.




#### **Table 79.4** (continued)


**Illustration 79.8** (**a**, **b**) Fronto-orbital advance and remodelling

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India **Illustration 79.9** Sagittal remodelling/total vault remodelling

©Association of Oral and Maxillofacial Surgeons of India

**Illustration 79.10** Asymmetric fronto-orbital advancement for unicoronal synostosis

©Association of Oral and Maxillofacial Surgeons of India

**Illustration 79.11** (**a**, **b**) Monobloc advancement

©Association of Oral and Maxillofacial Surgeons of India **Illustration 79.13** Posterior vault distraction

©Association of Oral and Maxillofacial Surgeons of India

**Illustration 79.12** Subcranial Le Fort III

©Association of Oral and Maxillofacial Surgeons of India

**Illustration 79.14** (**a**) Facial bipartition. (**b**) Box osteotomy to correct hypertelorism

#### **79.2.5 Management in Middle Childhood (8–12 Years)**

During this period routine monitoring is necessary, and as the face and dentition develop, attention can be turned to managing the midface and occlusion. During the transition from the deciduous to permanent dentition, it is important to have an orthodontic assessment—so that a defnitive orthodontic/orthognathic plan can be developed. One of the major factors that may prompt early midface surgery would be the development of OSA; thus regular questioning and targeted investigations at review appointments are necessary. In considering orthodontics it is important to be mindful of the fact that repeated courses of orthodontics will lead to root shortening and also potentially exhaust the tolerance and cooperation of the patient and his/her family [18].

In general, the routine correction of hypertelorism can be safely performed from about the age of 8 years; however this is determined by the chosen technique (facial bipartition vs box osteotomy) (illustration 79.14a, b) and whether an early midface advancement is necessary for the management of OSA [19]. As with all surgery aimed primarily at improving facial appearance, the indications, objectives and expectations of surgery must be discussed at length with the patient and his/her family and a consensus reached. The input from specialist child psychologists is often very helpful. The transition from primary to middle or secondary school is often traumatic, and interventions before this time can be very helpful from a psychological perspective, but it needs to be acknowledged and accepted that further surgery at the completion of growth may well be necessary [18].

#### **79.2.6 Management in Adolescence and after the Completion of Growth**

At this stage in development, defnitive corrective surgery (when necessary) should be planned and an integrated orthodontic/surgical plan developed. In the syndromic cases, ongoing monitoring for functional and developmental issues is required, and as the child matures, the drive and the responsibility for decision-making will move towards the patient and away from their parents. Many adolescents at this stage are tired of multiple hospital appointments and are not keen on further interventions; in these circumstances it is important to work with the patient and their family to provide care but also respect the patient's wishes and desires. It is better to postpone treatment rather than have a half completed course of orthodontics with poor cooperation and the consequent complications and fnally lose the confdence of the patient.

The planning of comprehensive surgery will need assessment in the following areas:


It is always best to offer and plan for a total correction in the frst instance. The discussion around further transcranial surgery is often key to the decision-making. Many patients and families do not want to undertake any further transcranial surgery, in spite of the signifcant benefts, particularly for hypertelorism or dystopia corrections. None the less these procedures can offer signifcant improvements in the fnal result [19].

For residual skull defects of approximately 2 cm diameter or larger, it is usual to offer some form of reconstruction; this could be autologous (usually cranial bone), or alloplastic. Alloplastic reconstructions may be of a variety of materials and can be CAD/CAM designed or shaped intraoperatively. One of the most common residual defects following a frontoorbital advancement is a degree of temporal hollowing; this can be effectively addressed with the use of mouldable hydroxyapatite synthetic bone material. This technique can be used to satisfactorily address minor skull irregularities and defects, and it is also possible to combine this technique with the use of alloplastic custom-made cranioplasties (e.g. titanium or PEEK) [20].

The assessment of orbital position is critical to deciding on what operative procedure to offer. The combination of hypertelorism and marked maxillary narrowing (particularly if the upper incisors are crossed), as is often seen in Apert syndrome, lends itself to correction with a facial bipartition; this technique can also be used early as the bone cuts do not result in damage to the dentition. The major drawback of this technique is that orbital asymmetries cannot be addressed. The more conventional box osteotomy is used to effect asymmetric movements, hypertelorism and dystopia corrections. The overall aesthetic outcome is often enhanced with nasal augmentation and soft tissue surgery, but the fnal improvement (particularly in severe hypertelorism cases) unfortunately often does not match the skeletal changes achieved.

The upper midface can be advanced, either as part of the bipartition procedure, transcranial Le Fort III (monobloc), subcranial Le Fort III or Le Fort II. These procedures can be performed conventionally with bone grafting and fxation with either absorbable or titanium plates and screws or with the use of distraction techniques. If distraction is being utilised, the devices can be a halo-based external device or buried devices. It is sometimes helpful to combine external distraction devices with buried devices which facilitate the early removal of the somewhat cumbersome halo device for the retention period [21]. In addition to advancement movements, it is possible to incorporate height changes, but rotatory movements (e.g. to correct the upper dental midline) are very diffcult unless the symmetry is equal at all facial levels. Furthermore if the maxillary advancement required has a signifcant differential between the upper component and dental component, it is possible to combine a Le Fort III (transcranial or subcranial) or a monobloc advance with a simultaneous Le Fort I osteotomy. This additional level of movement allows for differential advancements and/or height changes as well as rotations at the lower level. See case series in Fig. 79.5 of Crouzon syndrome.

The mandible including the chin should be considered as one would for conventional orthognathic surgery, but caution should be exercised in setback procedures as correction of the occlusion to a retrusive maxilla may worsen or precipitate OSA.

Nasal deformity is best dealt with as close to the end of treatment as possible; the range of deformity is considerable; each patient should be treated on their own merits. In cases with severe defciency, dorsal augmentation with alloplastic or autologous material may be necessary, and this can be refned with nasal tip surgery.

The fnal phase of surgery is the management of the soft tissues, and again a variety of techniques can be employed to improve the overall aesthetic result. As well as rhinoplasty techniques, facelifting, brow suspension, eyelid surgery, soft tissue augmentation with fllers or fat transfer and soft tissue reduction with direct excision or liposuction all have their place.

See Table 79.2 for an outline of the management of common clinical problems and Table 79.4 for an outline of surgical procedures.

#### **References**


of shunt-induced craniosynostosis. J Craniofac Surg. 2015 Jan 1;26(1):e70–2.


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**Part XXI**

**Malignant Pathologies of the Oral and Maxillofacial Region**

**80**

## **Premalignant Lesions and Conditions of the Oral Cavity**

El Mustafa, Sat Parmar, and Prav Praveen

#### **80.1 Premalignant Lesions**

It is well established that oral cavity cancer develops in a two-step process and, consequently, that most malignant ulcers are preceded by a precursor lesions [1]. These lesions are typically red or white patches referred to altogether in the 2007 WHO consensus statement as the group of potentially malignant disorders (PMDs) [2] (Table 80.1). Clinical identifcation of PMDs offers a window for intervention: eliminating diseased mucosa and exclusion of occult invasive cancers. This is important from a clinician's perspective on several fronts. Firstly, it is important to be able to recognise high-risk lesions among a multitude of innocent oral conditions that present with similar features. Some conditions such as oral lichen plans may have a potential for malignant change, but the condition is so prevalent that it becomes impractical to monitor every single patient with the disease. To avoid additional burdens on clinical services, the oral physician or surgeon needs to make a decision as to which patients must be kept under review at a specialist centre and which may be safely referred back for ongoing follow-up in the community. Among those who are reviewed at a specialist practice, ongoing decisions are made at each visit, when to intervene and to what extent one should be aggressive with the treatment plan offered. On a second front are the diffculties of recognition of tumour recurrences following treatment. Surgical treatment and radiotherapy change the tissue appearance and texture irreversibly. Among these patients, it is known that a proportion would develop either a second tumour at the site of surgery or a new tumour in a neighbouring area. It is challenging enough to identify precancerous lesions in nascent tissue, and thus the clinician must be much more vigilant in recognising potentially cancerous new

#### **Table 80.1** Potentially malignant lesions


lesions in patients under follow-up posttreatment of head and neck cancer.

Further to these concerns, we know that premalignant conditions tend to develop in what is known as feld change. This means that for any subsite within the oral cavity at which cellular nuclear damage resulted in a PMD (or even cancer), the adjacent mucosa is almost equally at risk of producing additional PMD lesions even if they appear normal to the naked eye.

Knowledge of the patterns and behaviour of PMDs (premalignant disorder) is thus an essential part of oral medicine and oral surgery practice.

The commonest PMDs are leukoplakia with an overall prevalence of 2.9% in the general population [3] and submucous fbrosis with a prevalence of nearly 11% in high-risk populations [4]. The risk for submucous fbrosis is specifc to populations where paan use is prevalent unlike the risk for leukoplakia which is universally applicable. Lesions are considered potentially malignant rather than premalignant. Clinical behaviour is unpredictable; some lesions remain stable; others regress, but in up to 30% of cases, oral malignancy is diagnosed within 5 years of follow-up. Cancer may arise from the lesion itself or at a different subsite within the oral cavity refecting the concept of 'feld cancerisation' explained previously.

It is important to note that a role for primary prevention in patients with leukoplakia is not confrmed. For example, smoking is a risk factor for the development of leukoplakia,

E. Mustafa · S. Parmar · P. Praveen (\*)

Department of Oral and Maxillofacial Surgery, Queen Elizabeth Hospital, Birmingham, UK e-mail: Prav.Praveen@uhb.nhs.uk

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1845

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_80

but smoking cessation does not necessarily reduce the risk of developing OCC. There is, however, beneft in screening for potentially malignant lesions, and this was demonstrated in a recent review of the US SEER-Medicare database of head and neck cancer. Yanik et al. [5] reported better treatment and survival outcomes in patients who developed oral cell carcinoma whilst under follow-up for a premalignant lesion [5]. This correlated with the fact that oral cancers were identifed at an earlier stage in this patient cohort. Patients without the beneft of such close observation tended to present with more developed or advanced tumour forms. A role for screening patients following treatment for head and neck cancer recurrence is not known, and thus secondary prevention is not currently known to be effective. It is likely, however, that the principle of recognising early tumours and potentially malignant lesions would still result in timely provision of therapy. Table 80.1 enlists premalignant lesions discussed in this chapter.

#### **80.2 Aetiogenesis**

Development of a malignancy is a complex multistep process resulting from failures in several regulatory cellular pathways. Dysplasia in oral cancer is usually the frst step in the malignant down spiral. Dysplasia is a descriptive term used on microscopic assessment. It indicates that the tissue has accrued a signifcant population of abnormal cells that display a pattern of nuclear damage that is known to herald cancerous behaviour. These changes are summarised in Table 80.2. Usually but not always, these changes are followed by unregulated hyperplasia (cellular multiplication). The tumour cells have gained autonomy meaning they escaped nuclear and immune mechanisms that limit excess growth and prevent accumulation of damaged cells. The fnal step is loss of integrity of the basement membrane at the boundary between mucosa and submucosa; the dysplastic cells begin to invade into the surrounding tissues or directly gain access to vascular channels. Each of these steps is controlled by molecular pathways directed by gatekeeper genes and gene products.

Two cellular or microscopic changes broadly defne oral premalignancy: *hyperplasia* which results from over activation of the retinoblastoma pathway and the development of various degrees of *dysplasia* due to mutations in the p53



gene. In health and normal physiology, genes along the retinoblastoma pathway activate transcription factors required for taking the cells from the indolent G1 to the active S phase. Overactivation of these genes leads to loss of control of orderly cell division resulting in epithelial hyperplasia. A product of the CDKN2A gene, the p16 protein, usually keeps this stage of cell cycle in check. This protein may become inactivated either because of a mutation/deletion/epigenetic slicing of the parent gene CDKN2A or through direct degradation by a viral product, the E7 protein, of the HPV virus (relevant to the development of oropharyngeal cancer). The retinoblastoma pathway may also be directly upregulated by amplifcation of the Cyclin D1 gene, a proto-oncogene of the locus 11q13 [6].

With each cell division, there is a probability of errors arising in the nuclear DNA resulting in a defective daughter cell. Most errors are corrected during cell division, or the cells are removed by immune mechanisms. Defective cells that have escaped these reparative measures may still be suppressed by transcription factors that induce apoptosis. Apoptosis is triggered through p53, a tumour suppressor protein. The protein p14 is an alternative reading frame of the CDKN2A gene responsible for initiating the p53 pathway. Direct degradation of p53 by the E6 viral protein (HPVrelated cancer) or genetic mutations in the parent gene (in 60% of non HPV cancer) restricts protective physiological apoptosis leading to a shift in cell population and accumulation of dysplastic cells. The premise behind looking out for premalignant disorders is that oral mucosa will change appearance with the onset of dysplastic changes and that the extent of dysplasia does correlate with malignant potential. High-grade dysplastic lesions indicate treatment is required imminently, whereas mild dysplastic lesions may be observed and are even considered a feature of benign chronic infammation. Dysplasia is classifed according to several grading systems summarised in Table 80.3, the most common system in use being the one proposed by the WHO in 2005. Further

**Table 80.3** Grading systems for dysplasia


genetic changes are involved in progression towards invasiveness, but these are not as well defned as these are outside the scope of the chapter.

#### **80.3 Leukoplakia**

Idiopathic leukoplakia is the most common premalignant disorder. Nearly one in every 10 cases of oral cavity cancer (OCC) is known to arise in leukoplakia (Fig. 80.1), usually within 3 months of diagnosis of the lesion [5]. These lesions are defned as 'white plaques of questionable risk having excluded disorders that carry no increased risk for cancer' [2]. Table 80.4 enlists white lesions without a known malignant potential. These are rare, and thus most persistent white patches are best treated with suspicion until further evaluation.

Clinical variants of leukoplakia include homogenous plaques, nodules, speckled erythroleukoplakia and a distinct subtype discussed separately: proliferative verrucous subtype. Leukoplakia is present in less than 1% of the general population [5] but with greater prevalence reported among those older than 75 years of age and tobacco users of all age groups [7]. Men are twice as much likely to develop leukoplakia compared with women. In the Indian subcontinent, in regions where betel is consumed, prevalence rates approach 5% [8]. The annual risk of malignant transformation is estimated between 1 and 2% [9]. Larger non-homogeneous

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 80.1** Leukoplakia

#### **Table 80.4** Innocent white patches


**Table 80.5** Risk predictors for malignant transformation

lesions, particularly those on the tongue and foor of the mouth, are associated with the highest conversion rates to oral squamous cell carcinoma. Table 80.5 lists clinical risk predictors for malignant transformation.

Tissue biopsy is required to assess the degree of epithelial dysplasia, an independent and consistently reliable risk factor for malignant transformation. Liu et al., using a binary grading of dysplasia, found that patients with high-risk lesions (moderate/severe dysplasia) eight times as likely to be diagnosed with oral cancer as those with low-risk (no/ mild dysplasia) lesions [10]. Histological evaluation may also identify other conditions that are clinically indistinguishable from idiopathic leukoplakia such as hyperplastic candidosis, oral lichen planus variants, lichenoid reactions and discoid lupus.

Categorisation into high- and low-risk lesions is helpful in identifying target areas for surgical removal and those that may be safely observed but closely followed up.

However, in populations with high incidence of oral cancer, studies have shown oral leukoplakia as foci of invasive cancer and have advocated surgical excision of these lesions.

Toluidine blue dye improves visual detection of highrisk mucosa [11] and helps determine the extent of peripheral margins required for complete excision. It is not established whether surgical intervention reduces the risk of subsequent cancer, but a resection specimen may upgrade the histological evaluation or identify areas of occult focal invasion. Recurrence following surgery is observed in 10% of cases [12]. Laser surgery is effective in controlling lowgrade leukoplakia, but signifcantly higher failure rates of up to 9% were reported in high-grade lesions and erythroleukoplakia [13]. Recent reviews have examined photodynamic therapy as a treatment option particularly helpful in controlling widespread and multifocal leukoplakia [14]. Partial and complete response rates as high as 70–100% were reported, but the range of photosensitisers used and photo-irradiation protocols applied varied greatly between individual authors.

Medical treatments for oral premalignancy include systemic vitamin A, systemic beta carotene and topical bleomycin. These were shown to control premalignant lesions, but a 2016 Cochrane review concluded that relapse rates were high and that transformation into oral cancer was not effectively reduced [15].

#### **80.4 Proliferative Verrucous Leukoplakia**

Proliferative verrucous leukoplakia (PVL) is a distinct and aggressive form of leukoplakia with one of the highest known malignant transformation rates. It is typically diagnosed in elderly women (4:1 female ration) without a history of tobacco use [16]. Aetiology is thus largely unknown. Lesions often start as isolated fat white plaques but gradually spread to become diffuse and multifocal with a characteristic warty appearance (Fig. 80.2). There typically is no erosive component. The lesions tend to present on the tongue or buccal mucosa or well as the alveolar ridge. They can be mistaken for hyperplastic candidosis or frictional keratosis particularly in denture wearers. Histological appearance is dependent on the stage of the disease ranging from benign hyperkeratosis to dysplastic keratosis merging into verrucous carcinoma. Malignant transformation may also happen simultaneously at multiple foci, and this is one of the clearest manifestations of the feld cancerisation concept introduced earlier. Verrucous carcinoma is a squamous cancer with welldifferentiated histopathological architecture that displays very little cellular atypia.

PVL is a lesion that benefts from excision biopsy rather than an incisional sample (see biopsy discussion below) for it is estimated that 20% of verrucous lesions, if adequately sampled, would reveal foci of conventional pattern squamous cell carcinoma. Local control is, however, diffcult with high recurrence rates following surgical excision and greater malignant transformation rates in excess of 70% [17]. It is also one of the most diffcult lesions to follow up, requiring multiple biopsies to monitor behaviour over time.

#### **80.5 Erythroplakia**

Erythroplastic lesions (Fig. 80.3) are similarly defned to oral leukoplakia but as red velvety lesions following exclusion of other named entities. It is a rare disorder with prevalence

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 80.2** Proliferative verrucous leukoplakia

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 80.3** Erythroplakia

between 0.01 and 0.2% but a much higher transformation rate compared to leukoplakia, reportedly between 51 and 90% [16]. Clinical appearance tends to follow one of three patterns: the homogenous, granular and speckled types [12]. Most common subsides are the palate, the buccal mucosa and the foor of the mouth. Lesions are rarely multicentric and may present a similar clinical appearance to erosive and atrophic oral lichen planus, erythema migrans, stomatitis, candidosis, lymphatic malformations and desquamative gingivitis (e.g. vesiculobullous lesions and gingival lichen planus). Speckled erythroplakia and leukoplakia most likely refer to the same disorder with red appearance correlating to highrisk epithelial dysplasia. Treatment options are surgical excision, laser excision or evaporation as per leukoplakia with a lower threshold for application for wide local excision due to the higher risk of cancer development.

#### **80.6 Submucous Fibrosis**

Oral submucous fbrosis is progressive scarring disorder linked to the use of betel products (paan). Additional risk for oral squamous cell carcinoma is conferred by the addition of slaked lime to the betel quid or concurrent use of tobacco. The active ingredients in paan include arecoline, copper and polyphenol fragments (favonols, tannins) which stimulate an intense acute infammatory response characterised by a polymorphic infltrate and vascular dilatation. This gives way to a chronic immune response and constrictive vascular changes that end with obliteration of blood vessels in the affected region. Over time, this leads to an epithelial to mesenchymal transition mediated by TGF-β [18]. Fibroblasts are activated, and collagen is deposited steadily replacing the submucous tissues with hyalinised cartilage almost devoid of cellular components. Several genes are known to associate with the risk of developing submucous fbrosis including MMP3 gene promoter region and CYP1A1/CYP2E1 genes,



but the genetic basis for transformation into squamous cell carcinoma is not currently defned. Table 80.6 summarised the histopathological evolution and progression of submucous fbrosis.

Consumption of paan is common in Southeast Asia and the Western Pacifc but is now also seen in Europe and North America. It is estimated that more than half a billion persons consume betel worldwide [19]. Early presentation refects the early histological picture with non-specifc infammatory mucosal changes. The diagnosis becomes clearer when early changes are replaced by the characteristic hypo-vascular blanched appearance with a fbrous texture although these changes may be patchy or reticular causing potential confusion with unrelated mucosal changes (e.g. lichen planus). In general, submucous fbrosis tends to present in young adults (predominantly males) with worsening trismus (37.2% of patients), painful dysesthesia (25.9%), excess salivation (22.5% of patients) and recurrent ulceration. Clinical fndings on examination are white patches particularly in the buccal mucosa (20.8%) and the palate (17.7%) followed by the foor of mouth and the retromolar trigone [20]. Clinical signs develop within 3–5 years following commencement of chewing betel preparations. Patients are 19 times as likely to develop oral cancer particularly with betel quid containing tobacco [4]. Malignant transformation rates are reportedly 4–13% [21].

Conservative and medical measures are considered for the early clinical stages. This includes physiotherapy, immune modulators steroids and promoters of blood fow such as pentoxifylline. Many other medical treatments are reported but none with defnitive clinical beneft.

Surgical options are limited and complete excision unlikely, but surgery is usually indicated for local release of

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 80.4** Oral lichen planus

retromolar or buccal scarring to help relieve trismus. Release of trismus is usually necessary at the mouth opening of 25 mm and less and is achieved with incisions, local V–Y faps and masticator muscle myotomy, resurfacing the defect with the buccal fat pad or other grafts.

#### **80.7 Oral Lichen Planus**

Lichen planus (LP) (Fig. 80.4) is a prevalent infammatory much cutaneous disease affecting 5% of the population worldwide. The pathogenesis is not well understood but is essentially an autoimmune response to the epidermal basal cell layer mediated by cytotoxic T cells. Characteristically, T cells are seen to infltrate into the lamina propria on microscopy and the damaged basal keratinocytes degrade into apoptotic residues known as civatte bodies (not pathognomonic for LP) [22]. Aetiology is unknown, but it is well recognised that appearances of lichen plans can result from a hypersensitivity reaction to nonsteroidal anti-infammatories, angiotensin-converting enzyme inhibitors and dental amalgam. These reactions are more commonly referred to as lichenoid mucositis. In rare instances, the disease associates with viral hepatitis (B and C), but in most patients LP, there is no triggering factor. Stress is thought to be a contributing factor.

Commonly, oral lichen planus (OLP) presents as reticular white patterns on the buccal mucosa or the tongue known as Wickham's striae. Many varieties and presentations are recognised such as desquamative gingivitis, plaque form and an unusual form that presents with vesicular bullae. An erosive form is also recognised giving the appearance of the highrisk erythroplakia and mixed red and white lesions [23]. Some authors use the term erosive OLP to refer to the ulcerated type of lesion and erythematous OLP as the commoner type which affects atrophied buccal mucosa (usually seen with reticular lesions). Distribution is usually symmetrical, a feature it shares with discoid lupus.

It is not clear whether oral lichen planus (OLP), a relatively common benign condition, is an independent risk factor for malignancy. A meta-analysis of 7806 patients concluded that just over 1% of patients OLP develop oral cavity cancer [24]. The highest risk subsites were predominantly the tongue (51%) and the buccal mucosa (32%). Malignant transformation was three times as likely in females as it was in men. It is proposed that changes at lower-power magnifcation of oral leukoplakia resemble lichen planus or that lichenoid changes in epithelial dysplasia are common. Clinically, there is overlap between the clinical appearance of the various types of OLP and between erythroleukoplakia and verrucous leukoplakia. A diagnosis of OLP is more likely in symmetric lesions, but only a biopsy demonstrating epithelial dysplasia would confrm truly high-risk lesions. Correlation between malignant change and certain subtypes of OLP, namely, the erosive and plaque-like forms, has not been consistent. Interestingly a co-existence with proliferative verrucous leukoplakia has been noted by several authors [25, 26].

#### **80.8 Chronic Hyperplastic Candidosis**

*Candida* is present in the oral cavity in between 40 and 60% of healthy individuals. Association between *Candida* infection and cancer is through smoking, an independent risk factor equally for the development of chronic hyperplastic candidosis (CHC) and premalignant mucosal lesions. Once hyperplastic candidosis is established, these lesions manifest and behave similar to homogeneous or speckled leukoplakia with 15% risk of progression to epithelial dysplasia [27]. CHC is usually resistant to antifungal therapy, and thus surgery is indicated particularly for well-defned lesions.

#### **80.9 Premalignant Conditions**

Premalignant conditions are a disparate group of rare congenital and acquired disorders of immune regulation, inheritable genetic instability and infectious diseases. Table 80.7 enlists conditions that associate with mucosal SCC followed by Table 80.8 which also provides a summary of clinical features, site distribution and risk probabilities for conditions that associate with the cutaneous type of squamous carcinoma. Reports of malignant transformations are generally few and data concerning the natural history of OCC limited. Conditions that rarely associate with oral SCC such as Plummer-Vinson syndrome are not discussed here.

**Table 80.7** Potentially malignant conditions: mucosal SCC


**Table 80.8** Potentially malignant conditions: cutaneous SCC


#### **80.10 Tissue Biopsy**

A sample of tissue is required whenever a premalignant disorder is suspected. Dysplasia cannot be visualised on clinical inspection. It is true that some lesions such as the speckled red and white lesions are most likely to harbour dysplastic cells, but it is hard to characterise white patches as dysplastic or not on clinical examination alone. Most sites within the oral cavity are accessible for a biopsy under local anaesthetic. General anaesthetic may well be indicated in some cases depending on tumour site particularly in the oropharynx or in patients not compliant with awake procedures. A biopsy may be obtained either by using a scalpel blade or through a punch biopsy applicator with pre-set width.

A small amount of local anaesthetic is administered locally within the site of the lesion for it provides pain relief and vasoconstriction through the action of an additive. Concentrations of 1:50,000 to 1:200,000 epinephrine are used as vasoconstrictor additives typically to lidocaine. Other vasoconstrictor agents include felypressin typically combined with prilocaine as a local anaesthetic. Care should be taken in patients who take anti-platelets agents or anticoagulant medications. The oral mucosa has a rich blood supply, and bleeding from small biopsy sites may prove to be diffcult to control.

Excision of the abnormal patch as a whole may be achievable in smaller lesions, but in large and extensive lesions, an incisional sample is indicated. The site for taking a biopsy in this case is important. A white lesion may contain within multiple foci, and a biopsy from a uniform looking area may miss an area of dysplasia or early invasive cancers. Within a white lesion, it is advisable to take a biopsy from a speckled area, an area where there is induration/thickening and an erosive patch or where there is frank ulceration. When there is ulceration, then removal of tissue from the centre of the ulcer may return tissue that is necrotic and hard for the pathologist to interpret. Thus, it is also advised to take a biopsy from the margin of the ulcer particularly if the margin is elevated or everted. A small extension to incorporate normal looking tissue is helpful to enable the pathologist to visualise pathological transition into normal background architecture and pick up subtle changes that may otherwise be diffcult to interpret.

The full thickness of mucosa is required for complete assessment. Invasiveness is impossible to interpret without inclusion of the basement membrane in the tissue biopsy. Traditionally that may not have been crucial for at the highest end of the dysplastic spectrum severe dysplasia is also considered to be at least as intra-epithelial neoplasia and in most cases surgical excision would be indicated. However, recent modifcations of the TNM classifcation system and the work of D'Cruz et al. have highlighted depth of invasion as an independent risk predictor for regional metastasis [31].

Thus a biopsy may not only identify the nature of the lesion and reveal unexpected invasiveness; it may also determine the next step in treatment whether surgical excision of the lesion is enough or whether the threshold for regional surgery (i.e. a neck dissection) is required as well.

Once the sample is removed, haemostasis is required with either bipolar diathermy or, in small sites, chemical cautery with silver nitrate that is useful too. Most biopsy sites lend themselves to primary closure with a resorbable suture, whereas particular sites such as the mucosa overlying the hard palate may be safely left to heal by secondary intent.

#### **80.11 Conclusion**

Clinical examination of the oral cavity must include active screening for mucosal changes that are potentially cancerous. This may take place in the primary care setting, in dental practice, for these lesions are mostly asymptomatic and the patients may not be aware of their presence. A high index of suspicion is required for it is well known that although some lesions associate with known risk factors (e.g. oral submucous fbrosis), many lesions do not (e.g. verrucous leukoplakia). Clinical features may be ambiguous with some lesions that are red, erosive or speckled lending themselves to easier recognition compared with faint leukoplakia and subtle early changes in long-standing lichen planus. A low threshold for biopsy is recommended unless the lesion is demonstrably consistent with candidosis (i.e. may be clinically wiped off) or in the case of striated lichen planus that has remained consistent and well defned. Clinical photography is helpful in establishing objective documentation lesions for it is likely that the patient would be reviewed by different clinicians during follow-up. Once identifed and histology is characterised, then lesions require stratifcation into high-risk and low-risk categories in order to determine the long-term plan for the patients, namely, surgical removal versus clinical observation, and the appropriate recall intervals for future follow-up. As discussed above, the treatment options are diverse and are tailored to the size of the lesion and degree of epithelial dysplasia. Although surgical removal does not eliminate the risk of malignant change entirely, early identifcation and close follow-up of premalignant lesions offer the best chance for achievement of good local control if and when oral cancer develops.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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## **Oral Squamous Cell Carcinoma: Diagnosis and Treatment Planning**

Vijay Deshmukh and Kishore Shekar

#### **81.1 Background and Incidence**

The incidence of oral and oropharyngeal SCC is on the rise. Each year approximately 263,000 new cases of oral cancer are detected worldwide, and 127,000 people die of the disease [1]. In India it is the third most common cancer and accounts for almost 40% of deaths. Among men it is the second most common site, and in women it is the fourth in India [2]. In 2012, the incidence rate for male was 10.1/1,00,000 and for female 4.3/1,00,000 [3].

#### **81.2 Introduction**

Oral carcinoma commonly called as the oral squamous cell carcinoma (OSCC) occurs as an ulceroproliferative lesion of the oral mucosa affecting any site starting from the lips to the oropharynx. The commonest sites are gingivobuccal sulcus of mandible followed by the tongue and foor of the mouth. It should be understood that Indian cancer is much different to other parts of the world. The habit of the tobacco chewing (smokeless tobacco) and pan masala, i.e., a mixture of the tobacco, betel nut, and unknown chemicals used for the color and favors, is the commonest cause. Classical Indian cancer is the gingivobuccal sulcus (GBS) of the mandible due to the

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_81) contains supplementary material, which is available to authorized users.

Maxillofacial and Microvascular Surgeon, Deshmukh Institute of Maxillofacial Surgery and Research Centre, Aurangabad, India

Department of Dentistry and Maxillofacial Surgery, JIIU'S Indian Institute of Medical Sciences, Maharashtra, Jalna, India

K. Shekar

Head and Neck Surgeon (OMFS), Ninewells Hospital and Dundee University Medical School, Dundee, UK e-mail: Kishore.Shekar2@nhs.scot

placement and holding of the tobacco-lime mixture, in the area. Over the last three decades, pan masala has become popular, due to the easy availability in pre-mixed packed. This maybe chewed or kept in the oral cavity, i.e., GBS, which leads to continuous action of the contents on the oral mucosa. The constant irritation leads to fbrosis and with time results in submucous fbrosis.

#### **81.3 Etiology of Oral Carcinoma**

Etiology of oral SCC is multifactorial. Local irritants contribute signifcantly to the conversion of a premalignant process to invasive carcinoma. Damage to the epithelial layer followed by the basement membrane and submucosa secondary to chemical and mechanical injury leads to fbrosis of the mucous membrane.

The prominent etiological factors are:

1. Tobacco consumption—All forms of tobacco smoke as well as smokeless have carcinogenic potential. Evidence for smokeless tobacco causing oral and pharyngeal cancer was evaluated and confrmed [4]. India is the third largest producer and consumer of smoked and smokeless forms of tobacco. Tobacco-related cancers account for nearly 50% of all cancers among men and 25% of all cancers among women with the burden of tobacco-related cancers in 2001 estimated to be nearly 0.33 million cases annually. It has been predicted that an incidence of sevenfold increase in tobacco-related cancer is expected between 1995 and 2025 resulting in an increase by 220% of cancer deaths simply related to tobacco use [5]. In India chewable tobacco is consumed in various forms. The traditional form is called the pan (Figs. 81.1, 81.2 and 81.3). Local form of smoking tobacco is called as bidi, which is a crude form of cigarette. This is considered to be more carcinogenic. It commonly causes carcinoma of the palate, oropharynx, and larynx.

**81**

V. Deshmukh (\*)

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_81

1854

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.1** Betel nut (areca nut). Various forms. Raw red in color and roasted white in color. It is broken in pieces with a special cutting device. Pieces are chewed with tobacco-lime mixture or with betel quid (pan)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.2** Pan masala (gutkha) pouches. Ready to eat mixture of tobacco, betel nut, lime, catechu, and unknown chemical coloring and favoring agents


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.3** Pan-betel quid. Betel leaf coated with lime-catechu-favored tobacco-betel nut. It is rolled, wrapped, and pinned with clove. Most commonly chewed in Indian subcontinent

or dried or may be cured before use by boiling, baking, or roasting. The abrasive mechanical property causes attrition of teeth and physical damage to the mucosa. This sandpaper action makes the mucosa more susceptible to the chemical properties of beetle nut. In India alone 38 different combinations of areca nut with tobacco have been documented (Fig. 81.1). The number of patients with a pan masala chewing habit (68.0%) was higher than the number of patients with betel nut (17.4%) or betel quid chewing habits (14.6%). The chewing of pan masala is associated with earlier presentation of oral submucous fbrosis (OSMF) as compared to betel nut chewing [9]. Pan masala (Fig. 81.2) is the artifcial mixture available in small pouches having contents of tobacco, betel nut, spices, coloring and favoring agents, preservatives, as well as unspecifed agents. This has proven to be highly carcinogenic. Consumption of this mixtures leads to OSMF which is a precancerous condition. Development of precancerous lesions like leukoplakia in preexisting fbrosis potentiates carcinoma conversion. Betel nut is also consumed with a pan (Fig. 81.3) a freshly prepared mixture on the betel leaf with tobacco, slaked lime, catechu, and clove. This is chewed over a longer time and remains in contact with oral mucosa causing mechanical and chemical irritation. The important favonoid components in areca nut are tannins and catechins. These alkaloids undergo nitrosation and give rise to N-nitrosamine which might have cytotoxic effect on cells [10].

4. Nutritional defciencies—Dietary defciencies of vitamin A, folate, ribofavin, iodine, and iron add to the risk of cancer. High dietary fber; vitamins C, E, and A; and selenium offer protection against cancer [11, 12].


#### **81.4 Precancerous Situations of Oral Cavity**

Precancerous situations can be broadly divided into precancerous conditions and precancerous lesions. Precancerous condition's most commonly seen in India are oral submucous fbrosis (OSMF) and oral lichen planus. Precancerous conditions can be associated with the precancerous lesions (please also see Chap. 80 on premalignant lesions and conditions).

#### **81.4.1 Precancerous Conditions**

Precancerous conditions make every part of the oral cavity susceptible to cancer conversion as is seen in oral submucous fbrosis (OSMF). The phenomenon simulates feld cancerization. Development of a second primary despite adequate treatment of the frst is common. Sometimes two primaries at distant anatomical sites are noted in extensive long-standing OSMF.

#### **81.4.2 Oral Submucous Fibrosis (OSMF)**

Oral submucous fbrosis is a chronic insidious disease of the oral mucosa characterized by loss of mucosal elasticity and excessive fbrosis (Figs. 81.4, 81.5 81.6 and 81.7). It is always associated with juxta-epithelial infammation and progressive hyalinization of lamina propria [13]. Oral submucous fbrosis (OSMF) is predominantly seen among betel quid chewers and pan masala chewers in India. OSMF generally starts at the RMT (retromolar trigone), anterior faucial pillars, and the adjoining area of the soft palate. It extends to involve the buccal mucosa, commissure, lips, and rima oris. Resulting trismus is due to mucosal and muscle fbrosis in the masseter and pterygoids. Figures 81.8 and 81.9 shows the traumatic ulcers caused in buccal mucosa and RMT area in OSMF cases mainly due to the limited mouth opening and fbrosis. In such cases early dental intervention or extractions

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.4** OSMF (oral submucous fbrosis). Note fbrosis affecting RMT, faucial pillars, buccal mucosa, as well as rima oris

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.5** OSMF (oral submucous fbrosis). Note fbrosis affecting RMT, faucial pillars

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.6** OSMF (oral submucous fbrosis). Note fbrosis affecting lower lip and blanching of mucosa. Note pale nails due to anemia

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.7** Bald tongue in OSMF. Has high malignant potential

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.9** OSMF with traumatic ulceration from last molars

may be delayed due to the diffculty in access to the posterior teeth due to trismus. Such chronic traumatic ulceration may undergo malignant change as seen in Fig. 81.10.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.8** OSMF with traumatic ulceration from last molars

#### **81.4.2.1 Molecular Pathogenesis of OSMF**

Time and constant irritation lead to infammation with mucosal atrophy. It can thus be considered that induction of oral mucosal infammation by betel quid is a critical event in the pathogenesis of OSMF. Cytokines like interleukin-6 (IL-6), tumor necrosis factor (TNF), interferon-a (INF-a), and growth factors like TGF-b are synthesized at the site of infammation.

TGF-b1 is a key regulator of extracellular matrix (ECM) assembly and remodeling. TGF-b1 increases collagen production and decreases its degradation [14]. OSMF has characteristic clinical presentation depending on the stage of the disease. The majority of patients have intolerance to spicy food, roughness of oral mucosa, and varying degrees of diffculty in opening the mouth.

OSMF is a well-recognized potentially premalignant condition of the oral cavity. The transformation rate is as high as 7.6% over a period of 10 years [15]. In this group, primary malignancy develops in the buccal mucosa extending to involve the retromolar trigone. This is unique in the context

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.10** Malignant transformation in posterior buccal mucosa in a case of OSMF, accompanied by chronic trauma form tooth

of the Indian subcontinent, as pure tobacco chewing habit has decreased and is replaced by the gutkha chewing habit. Tobacco-lime preparation used to be kept in the GBS or the foor of the mouth for longer period. This led to leukoplakia and/or erythroplakia, followed by malignant transformation. The current preparation is not constantly placed in the GBS but chewed for long time and swallowed. The chemical effect leads to OSMF and feld concretization.

#### **81.4.3 Oral Lichen Planus**

Oral lichen planus (OLP) tends to often present bilaterally as white striae on the buccal mucosa. Any mucosal site in the mouth may be involved. Other sites, in decreasing order of frequency, may include the tongue, lips, gingivae, foor of the mouth, and very rarely palate [16].

Six clinical forms of oral lichen planus are recognized [17]: reticular, erosive/ulcerative, papular, plaque-like, atrophic, and bullous. Atrophic/erosive lichen planus is associated with a risk of cancerous transformation [18]. Patients with OLP tend to be monitored closely to detect any potential change early.

The rate of malignant transformation in individual studies ranged from 0 to 3.5%. The overall rate of transformation was 1.09% for OLP.

#### **81.4.4 Precancerous Lesions**

Precancerous lesion is a pathology of the oral mucosa which has a tendency to transform into the squamous cell carcinoma. The commonly prevalent lesions are leukoplakia erythroplakia, carcinoma in situ, and smoker's palate.

#### **81.5 Diagnosis of Oral Squamous Cell Carcinoma (OSCC)**

Diagnosis of oral squamous cell carcinoma is not a challenging task except in the cases of an unknown primary. History of risk factors, classic clinical appearance of an indurated ulcer, involvement of lymph nodes, and destruction of bone are common features in advanced disease.

#### **81.5.1 Clinical Features of Oral Carcinoma**

Oral squamous cell carcinoma often presents as an indurated ulcer, exophytic growth, indurated non-ulcerative patch (endophytic), or a combination of the above appearances. Figures 81.11, 81.12, 81.13, 81.14, 81.15, 81.16, 81.17, and 81.18 shows the various clinical presentation of SCC in tongue. Fig. 81.19 shows multiple primary tumors arising in case of OSMF.

Important parameters to be recorded at the primary site in clinical examination are site of the tumor; size; extension to involve adjacent structures like the skin, muscles, bone of maxilla and/or mandible, and skull base; and extensions into compartments such as the paranasal sinuses, nasal cavity, orbit, pterygoid space, masticatory compartment, and infratemporal fossa. Regional spread to the lymph node basin in the neck needs clinical and radiologic correlation. Evaluation of distant metastasis to lungs and bones forms a part of the staging process.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.11** Precancerous lesion of the tongue—diffuse leukoplakia. Lesion has a potential to undergo SCC

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.12** OSCC of the tongue—inverted margins. Lesion not associated with any habit. These lesions often can have genetic predilection and behave aggressively

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.13** OSCC of the tongue—everted margins. Lesion can behave aggressively often associated with tobacco-related habit

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.14** OSCC of the tongue—exophytic growth. Lesions have nonaggressive behavior with better prognosis

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.15** Another case of OSCC of the tongue—exophytic growth. Lesions have nonaggressive behavior with better prognosis

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.16** OSCC of the tongue—ulcerative patch. Lesion is not associated with any habit. Genetic predilection

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.17** OSCC of the tongue—non-ulcerative patch. Lesion is frequently associated with smoking

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.18** OSCC of the tongue—verrucous growth. Lesion generally has dormant behavior with better prognosis

**Fig. 81.19** Intraoperative picture. Multiple primary tumors—SCC in OSMF. Rt.GBS/BM—resected, with Tongue-Rt. side. Either of these can be considered as Second Primary Tumour (SPT)

#### **81.6 Imaging in OSCC Diagnosis**

The minimum radiologic investigation for the primary site and neck should include imaging from the skull base to the clavicle. Staging of the chest is to detect both metastatic disease and synchronous tumors. MRI and/or CT with contrast is considered to be the gold standard. In poorer socioeconomic background, one could consider ultrasound scan of the neck as a staging modality. This will however not adhere to the current international guidelines. In our units the minimum standard is a MRI of the neck (including the primary) and CT chest. A double-contrast CT of the neck is as valuable as a MRI. Radiologic examination provides a greater accuracy in the staging process. Prognosticators such as depth of invasion and extracapsular spread in lymph nodes can be studied with good accuracy.

Where there is involvement of bone, a MRI and CT will provide better defnition for resection. Marrow signal changes can only be evaluated on a MRI. The CT provides

©Association of Oral and Maxillofacial Surgeons of India

better information on cortical erosion. In addition a thin slice CT helps in 3D planning prior to free fap reconstruction.

The role of a PET-CT is limited. Its primary indication is to detect an unknown primary prior to targeted biopsy. A further role for the PET-CT is in post-radiotherapy evaluation of the neck (Fig. 81.20).

MRI scans offer better accuracy of soft tissue extension of tumor. Studying fat planes between muscle groups allows for compartment resections in T4 tumors.

#### **81.7 Tissue Sampling**

Incisional biopsy is the gold standard in the diagnosis of squamous cell carcinoma. FNAC is used for the detection of lymph node metastasis. However with the increased accuracy in MRI and USS reporting, this modality is used less. Biopsy tissue should be taken from the most indurated portion of the tumor. Taking a biopsy from the summit or the center of an ulcer may yield a false-negative result. Scalpel, punch, and low-voltage electrocautery are all good options. Minimum size of the sampled tissue should be ideally 6 mm in all three dimensions. Mapping biopsy from multiple sites may be required at times to evaluate the extent of involvement and to prevent a falsenegative result. This is especially the case when a tumor develops in the background of a premalignant lesion.

Deep biopsy is required to get estimation on the depth of invasion (DOI). In cases of exophytic lesions, tumor thickness may cause diffculty in getting deeper tissue; in such cases tumor margin area can be chosen. In order to obtain a good-quality oral biopsy, the clinician should avoid crushing the sample with the tissue-holding forceps, infltrating anesthetic solution within the lesion, using an insuffcient volume of fxing solution and taking insuffcient amount of tissue in extension and depth. The specimen should be handled gently, avoiding any crushing, and introduced in the fxing solution such as 10% formalin.

In inaccessible areas, due to the site of tumor or reduced mouth opening, it is good practice to carry out an examination under anesthesia to evaluate the extent of the tumor. This also provides an opportunity for the lesion to be accurately biopsied in a more controlled environment of theaters.

#### **81.7.1 Histopathology**

Pathologist is expected to report on the tumor grade—welldifferentiated squamous cell carcinoma, Grade 1; moderately differentiated squamous cell carcinoma, Grade 2; or poorly differentiated squamous cell carcinoma, Grade 3. Well-differentiated tumors resemble normal squamous epithelium to a large degree (Fig. 81.21), poorly differentiated tumors exhibiting little or no histologic traits of the squamous phenotype, and moderately differentiated tumors having an intermediate morphology between the two ends of the spectrum. Higher grades have strong potential for recurrence and lymph node metastasis [19].

Several prognostic indicators have consistently demonstrated a correlation with disease-specifc survival, local and regional recurrence, and lymph node metastasis in numerous single or multicenter studies. The prognosticators are depth of invasion (DOI), pattern of invasion (POI), perineural invasion (PNI), lymphovascular invasion (LVI), and extranodal extension (ENE).

#### **81.7.2 Depth of Invasion/Tumor Thickness**

It is important to differentiate between depth of invasion and tumor thickness. The DOI is a more predictable prognostica-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.21** Well-differentiated OSCC. H&E 10x

tor compared to the latter. It is known that exophytic tumors (verrucous carcinomas being the prototype) or predominantly exophytic tumors have a good prognosis, whereas endophytic or deeply infltrating tumors are aggressive [20]. Depth of invasion (DOI) is an important independent factor in prognosis with strong effect on disease-free survival and overall survival, correlating with propensity for nodal spread better than tumor size in oral cancer [21–25]. In the foor of the mouth, 1-cm-wide tumor infltrating at 0.7 cm depth will likely have a worse outcome and carries a higher risk of neck metastasis than a 2-cm-wide tumor with microinvasion or superfcial invasion (e.g., less than 2 mm in thickness) [26–28].

#### **81.7.3 Pattern of Invasion**

Pattern of tumor invasion is an important prognostic factor. Tumor interface abutting deeper tissues has better prognostic value as compared to multiple tumor satellites into the deeper tissues [20].

#### **81.7.4 Perineural Invasion (PNI)**

PNI presence is a soft indicator for local recurrence and decreased survival. Multiple studies have shown conficting results [29]. However it is one of the most important predictors of neck metastasis [30] alongside DOI. PNI increases the rate of occult metastasis [31].

#### **81.7.5 Lymphovascular Invasion (LVI)**

Histopathological presence of lymphovascular invasion has poorer prognostic outcome. The presence of LVI is associated with nodal spread or occult metastases [23, 32–34]. Literature review has conficting evidence regarding the importance of LVI.

#### **81.7.6 Bone Invasion**

It is common to see OSCC of GBS and retromolar trigone (RMT) invade the adjoining mandible, maxilla, and pterygoid column. This upstages the tumor to a T4.

The increased risk of local recurrence can be attributed to two factors—tumor character and margin status following resection. Invasion into the pterygoid spaces makes surgical resection diffcult. Close margin is expected in these advanced tumors.

Mandible infltration can be of periosteal fxation, cortical erosion, or medullary invasion. Deeper invasion has poor prognosis [35] (Fig. 81.22).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 81.22** OSCC with bone invasion. H&E 10X

#### **81.8 Neck Assessment in OSCC**

A positive neck node is the single most important prognosticator for disease-free survival at 5 years. Size, number of levels involved, fxation to adjacent structures, and extranodal extensions (ENE) are of signifcance in lymph node assessment of the neck.

In a N0 neck, the pickup rate of a sub-centimeter positive node is less than 50% on clinical examination alone. Use of radiologic examination increases the pickup rate to 90%. A staging neck dissection is the only modality that has a pickup rate greater than 98% [36–38].

A well-lateralized tumor often spreads to the ipsilateral neck. In 5% of patients, the frst echelon can be the contralateral neck. Tongue cancers have the propensity for skip metastasis and contralateral spread. For all other regions of the oral cavity, the frst echelon spread is at level I/II.

Depending on the literature one reads, the specifcity and sensitivity between MRI and CT are confusing. The authors recommend that the radiologist choose the modality he has the greatest confdence in reporting. Ultrasound scan as a screening tool is useful in the outpatient setting.

Radiologic signs of nodal involvement are increases in size of the lymph node, obliteration of the fatty hilum, increased vascularity, an ill-defned outline, and intranodal necrosis. Ten millimeters or more in an axial section are considered positive for nodal involvement in the neck. However, false-positive or false-negative results of 15–20% are noted in the literature [39, 40].

#### **81.9 Distant Metastasis**

Distant metastasis needs to be suspected in lungs and vertebrae. Evaluation is done by CT alone or a PET-CT scan.

#### **81.10 TNM Staging System**

Cancer staging can be divided into a clinical stage and a pathologic stage. In the TNM (Tumor, Node, and Metastasis) system, clinical stage and pathologic stage are denoted by a small "c" or "p" before the stage (e.g., cT3N1M0 or pT2N0). This staging system is used for most forms of cancer. Accurate staging is critical as treatment is often based on clinical and radiologic stage.

Currently AJCC eighth Edition is used; this includes both the depth of primary tumor invasion and extracapsular extension of lymph node metastases. The AJCC eighth Edition OSCC staging system showed improved disease-free survival discrimination between overall stages and between T categories, while AJCC seventh Edition did not [19].

#### **81.10.1 AJCC Eighth Edition Clinical Staging System**

T—Primary tumor.

Tx—Primary tumor cannot be assessed.

Tis—Carcinoma in situ.

T1—Tumor ≤ 2 cm in greatest dimension, ≤ 5 mm depth of invasion (DOI not tumor thickness).

T2—Tumor ≤ 2 cm with DOI > 5 mm or tumor > 2 cm and ≤ 4 cm with DOI ≤ 10 mm.

T3—Tumor > 2 cm and ≤ 4 cm with DOI > 10 mm or tumor > 4 cm with DOI ≤ 10 mm.

T4—Moderately advanced or very advanced local disease.

T4a—Moderately advanced local disease.

Lip: tumor invades through cortical bone or involves the inferior alveolar nerve, foor of the mouth, or skin of the face (i.e., chin or nose).

Oral cavity: tumor invades adjacent structures only (e.g., through cortical bone of the mandible or maxilla, or involves the maxillary sinus or skin of the face). Note: Superfcial erosion of bone/tooth socket (alone) by a gingival primary is not suffcient to classify a tumor as T4.

T4b—Very advanced local disease. Tumor invades masticator space, pterygoid plates, or skull base and/or encases internal carotid artery.

Regional lymph nodes (N) ENE—extranodal extension.

Nx—Regional lymph nodes cannot be assessed.

N0—No regional lymph node metastasis.

N1—Metastasis in a single ipsilateral lymph node, ≤ 3 cm in greatest dimension and ENE (−).

N2—Metastasis in a single ipsilateral lymph node, > 3 cm but ≤6 cm in greatest dimension and ENE (−); *or* mets in multiple ipsilateral lymph nodes, ≤ 6 cm in greatest dimen-

**Table 81.1** AJCC prognostic staging groups according to the eighth AJCC edition


sion and ENE *(−); or* mets in bilateral or contralateral lymph nodes, ≤ 6 cm in greatest dimension and ENE (−).

N2a—Metastasis in single ipsilateral lymph node >3 cm but ≤6 cm in greatest dimension and ENE (−).

N2b—Metastasis in multiple ipsilateral lymph nodes ≤6 cm in greatest dimension and ENE (−).

N2c—Metastasis in bilateral or contralateral lymph nodes ≤6 cm in greatest dimension and ENE (−).

N3—Metastasis in a lymph node >6 cm in greatest dimension and ENE *(−) or* metastasis in any lymph node(s) with clinically overt ENE (+).

N3a—Metastasis in a lymph node >6 cm in greatest dimension and ENE (−).

N3b—Metastasis in any lymph node(s) with clinically overt ENE (+).

Distant metastasis (M).

M0—No distant metastasis (no pathologic M0; use clinical M to complete stage group).

M1—Distant metastasis.

AJCC prognostic stage groups are provided in Table 81.1.

#### **81.11 Treatment Planning for the Management of Head and Neck Malignancy**

#### **81.11.1 Introduction**

The management of head and neck cancer has undergone a sea change since the 1980s. The most important change that has been to the beneft of both patients and clinicians is the emphasis on evidence-based practice, and this has led to the development of the multidisciplinary team (MDT) or the tumor board as it is also known as.

In the more recent past, a new thought process is the practice of realistic medicine. The emphasis is on a more personalized approach to patient care and changing our style to shared decision-making. This is an approach that has been rolled out across Scotland.

#### **81.11.2 MAGIC: Making Good Decisions in Collaboration**

The key questions to be asked are:


#### **81.11.3 The Start of Treatment Planning**

The beginning of planning treatment starts on the receipt of a referral or patients' attendance. Patients with a history of a neck or salivary gland lump, non-healing ulcer of the oral cavity, bleeding, pain refractory to analgesia, hoarseness, and dysphagia are seen in the clinic within 2 weeks. Clinical examination should include the examination of the tongue base, tonsils, larynx, and nasopharynx with fexible nasoendoscope.

Developing a one-stop clinic helps in avoiding delays, and this has a signifcant impact on patients' psychological well-being. The one-stop clinic includes a biopsy on the same day for visible lesions and an ultrasound-guided core biopsy of neck lumps. The results of these preliminary investigations should be available in a week, setting up for a second meeting.

#### **81.11.4 The Second Meeting**

The second meeting or breaking bad news is perhaps the most important consultation in treatment planning. Patients are invited to attend the clinic with members of their family. Consultation is held in a quiet atmosphere in the presence of a clinical nurse specialist. It is important to be factual and honest. Unrealistic expectations should not be given. One must also bear in mind the impact the diagnosis will have on patients and their families. Empathy is very important. A good rapport with the patient and their family is invaluable.

#### **81.11.5 Staging Scans**

The minimum staging scans for head and neck cancer include a MRI and/or CT neck and CT chest. The rationale for staging is localization of the tumor and detection of regional and distant lymph node metastases. This has an importance in both the extent of therapeutic intervention and the diseasespecifc survival.

#### **81.11.6 Localization of Primary Tumor**

The localization of the primary tumor helps in the decisionmaking regarding the resectability of the lesion with clear margins. Tumor resection with a R1 margin is considered a futile procedure, and at the best it is palliative and at its worst just a "big biopsy." Anatomical areas of interest in localization are the skull base with particular interest to the carotid canal, involvement of the infratemporal fossa, the extent into the orbit, and in the case of tongue tumors proximity to the tongue base and larynx. Involvement of any of the above structure carries a very high risk of a positive or close margins resulting in increased risk of recurrence. Adjuvant treatment would then be inevitable. Functional outcomes are poorer.

MRI of the soft tissues is our preference for localization of the tumor as it helps in planning anatomic resection by determining the depth of infltration. This can be in the form of compartment resection—medial masticatory compartment resection for retromolar, soft palate, and posterior tongue tumors. Anatomical resections in tongue tumors uses muscle planes to identify margins and vascularity of the remainder tongue. The muscle groups most important to this are the mylohyoid, styloglossus, and stylohyoid. With tumors extending to the infratemporal fossa and skull base, a key landmark is the styloid. Prestyloid resections are considered straightforward, and a R0 margin is to be expected. Tumors in the poststyloid space carry the risk of a close margin.

Tumors involving the mandible and maxilla, in our practice, have a CT and MRI. The MRI helps in determination of marrow signal change and gives an aid to planning resection margins. The CT has a two fold advantage. CT helps localize cortical breach and complements the MRI in planning resection. It has also the added advantage of obtaining 3D models which helps in planning bone reconstruction with a free fap.

For malignancies of the salivary glands, our frst line of investigation remains an USS-guided core biopsy followed by a full staging of the neck and chest with MRI and CT, respectively. Tumors of the skull base and infratemporal fossa have both MRI and CT for localization of the primary.

For patients with suspected recurrence, especially under a free tissue fap transfer, the preferred modality is a PET-CT. PET-CT allows for a functional evaluation of the suspect area. In areas of previous surgery, the MRI has higher false-positive rates due to loss of fat planes and the inability to differentiate from scarifcation. A double-contrast CT scan may give better defnition of a recurrence; however both specifcity and sensitivity are low. The CT may give better spatial resolution. However false-negative results are high in glottic tumors and in mucosal disease with superfcial spread with CT.

The role of PET-CT in our practice is limited to neck lumps with unknown primary, small malignancies and in recurrent SCC. The major drawback for a PET-CT is poor anatomical depiction. Anatomical resection is not possible with a PET-CT alone. PET-CT adds little value in patients who have had recent surgery, i.e., biopsy. This invariably gives rise to a hot spot in infamed tissue. However, it is more sensitive than CT and MRI in detecting small malignancy. In more than 30% of cases, the PET-CT picks up malignancy not identifed by other modalities, and the majority of these are at the tongue base and supraglottic space.

Direct evaluation by examination under anesthesia and pan endoscopy provides probably the most accurate assessment for localization and planning surgery.

#### **81.11.7 Evaluation of the Neck**

There are numerous papers regarding the sensitivity and specifcity of different evaluation techniques—clinical examination, duplex ultrasound scan, CT scan, MRI, and PET. It is agreed by all that clinical examination of the neck provides the least reliable results of all and an adjunct investigation is necessary. It is the opinion of the authors that both CT and MRI give equally reliable results. The decision to which modality suits an individual team the best is reliant on the expertise of the head and neck radiologist in reporting the scans. In our own clinical practice, we feel that the MRI scan provides a good diagnostic value for staging the neck. In T1 tumors where there is a N0 neck clinically and radiologically, the evidence for staging neck dissection is limited. In cases where the MRI is equivocal, an USS with a FNAC (fne needle aspiration cytology) may be indicated. The USS would evaluate the lymph node for size criteria, presence of necrosis, and the absence of normal hilum. Lymph nodes that are rounded and greater than 1 cm in the neck are regarded to be pathologic until proven otherwise.

The role of USS should not be easily dismissed with the advent of cross-sectional imaging. The USS has many advantages. The spatial resolution of a good USS is better than that of a CT or MRI. Taking account of shape, contour, echogenicity, grouping, internal architecture, necrosis, and pattern of Doppler vascularity enhances the accuracy of US for nodal metastases to greater than 90%.

The USS is a cheap and quick modality that can be used. There is no radiation exposure. Its use as a surveillance scans cannot be surpassed in today's economic constraints. The one major drawback we have noted in our practice is that its sensitivity and specifcity are highly operator dependent. It cannot detect retropharyngeal, retrotracheal, and mediastinal lymphadenopathy. In these instances a CT or MRI gives better information.

PET-CT has a limited role in the staging of the neck. PET-CT is a useful tool to look at post-chemoradiation treatment response and to evaluate the neck following radiotherapy with residual neck mass. In the head and neck, misregistration of PET to CT can cause diffculty in reporting and increase false-positive results.

#### **81.11.8 The Role of Sentinel Node Biopsy**

The presence of metastatic disease to the neck is an important prognostic factor for disease-free survival in head and neck cancer. Recent papers by Anil D Cruz et al. have shown that patients who had an elective neck dissection fared much better than those on the watchful waiting strategy in both T1 and T2 tumors [29].

Sentinel node biopsy relies on the fact that metastases to the regional lymph nodes follow a predictive pattern in most cases. Migration of cancer cells is often to the frst echelon node. It is therefore predicted that if the frst echelon node is negative, the more distal node is unlikely to have cancer cell migration. Validation studies involving elective neck dissection have shown that there is 95% detection rate in sentinel nodes. The frst echelon node in most oral cancers is at level I or level II. In a well-lateralized tumor, the frst echelon node more often than not is on the ipsilateral side.

The indications for a sentinel node biopsy are:


Proponents of SLN biopsy claim the following advantages: reduces the morbidity of elective neck dissection, more accurate staging of the neck, and better prediction in those who have an unpredictable pattern of metastatic disease, therefore guides decision-making, helps identify skip metastases and micrometastases, and saves time and expense.

It is the opinion of the authors that sentinel node biopsy is a very good adjunct. Recent meta-analysis and systematic reviews suggest that high sensitivity, negative predictive value, and accuracy of SNB make this a valid diagnostic tool. NICE (National Institute of Clinical Excellence) guidelines recommend that a SLNB should be offered to all patients with T1 and T2 tumors with a node-negative neck. A word of caution, however, for T1 and T2 tumors with a tumor thickness greater than 5 mm, an elective neck dissection may still be indicated.

#### **81.11.9 The Multidisciplinary Team**

Following completion of all diagnostic requisites, the fndings are discussed at the weekly MDT or the tumor board meeting. The MDT has a core group of clinicians and healthcare professionals. The MDT comprises of maxillofacial surgeons, ENT surgeons, oncologist, speech and language therapist (SALT), dietician, clinical nurse specialist (CNS), head and neck radiologist, head and neck pathologist, restorative dentist, and cancer audit offcer to collect data. We have two clinicians from each of the subspecialties at our MDT. The MDT should not be regarded as a forum to advance individual pride or agenda. This is a group that helps balance evidence base in the management of patients and makes a realistic recommendation of treatment strategy.

The responsibility of the MDT is to protect and facilitate the patients' pathway through cancer treatment. The frst and foremost recommendation made by the MDT is the treatment intent—curative or palliative. This is followed by the treatment strategy—surgery or radiotherapy ± chemotherapy (Refer Chap. 84 to read about Adjunctive therapy in oral cancer).

At our MDT, the nature of surgery or the form of reconstruction is rarely discussed. The certainty of achieving tumor clearance and potential morbidity associated with the treatment form the majority of the discussions. Speech and language team assess the need for potential future PEG (gastrostomy) or nasogastric feed. Where there is a high index of suspicion that a PEG feed will be necessary, this is done pre-treatment. Dieticians help in planning feeding regimes both pre- and postoperatively. The restorative dentist offers an opinion on unrestorable teeth that need to be extracted at the time of surgery or prior to chemoradiation to reduce the incidence of future osteoradionecrosis.

#### **81.11.10 Planning Reconstruction**

The choice of reconstruction is numerous (Refer Chap. 82 to read about principles of surgical management of oral cancer. Chapter 85 deals with the access osteotomies to maxillofacial region while Chaps. 86 and 88 deals with soft and hard tissue reconstruction respectively). The preferred choice is dependent on the following factors:


The best form of reconstruction is to try and substitute like for like. A simple but effective way of looking at reconstruction would be:


#### **81.11.11 Conclusion**

A good functional MDT that practices evidence-based medicine with a realistic approach that is patient centered will be an effective oncology team that will deliver high-quality care for patients.

#### **References**


with primary surgery. Eur Ann Otorhinolaryngol Head Neck Dis. 2012;129(6):291–6.


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**82**

## **Principles of Surgical Management of Oral Cancer**

Sushma Mehta and Moni Abraham Kuriakose

### **82.1 Introduction**

Management of oral cavity cancers in a curative intent setting mainly involves surgery. The other treatment modalities such as radiotherapy and chemotherapy are most commonly used as adjuvant treatment based on the histopathological features. However, it is to be noted that surgery alone is insuffcient to treat oral cancer. Chemotherapy is either concurrent with radiotherapy or in very rare scenario used as induction therapy. The primary cancer treatment and risk factor reduction are of utmost importance to improve effectiveness of the primary treatment and to prevent development of second-primary cancers.

Ablative surgery has evolved over the years with the attempt to extirpate the tumor in its entirety with the understanding of the molecular tumor biology, pattern of tumor invasion of the tumors, as well as availability of better instrumentations.

With the advent of endoscopic assisted and roboticassisted neck dissection, the branch of oral oncology has truly made progress, thus improving visualization and threedimensional navigation; however it is still in its infancy and needs further research to understand the benefts over the conventional methods.

This chapter outlines details of ablative surgery and rationale for addressing neck (node positive/node negative) in patients with oral cavity cancers.

S. Mehta

M. A. Kuriakose (\*) Cochin Cancer Research Centre, Kochi, Kerala, India

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_82

### **82.2 Initial Evaluation and Staging**

Initial evaluation as for any other medical condition includes history, a clinical examination and investigations to form a diagnosis. The other two important aspects infuencing management of oral cavity cancer (mainly squamous cell carcinoma) are habit history and performance status. Table 82.1 describes the performance status scales.

Staging of the disease is particularly important as it helps the clinicians in better communication in a scientifc forum and forming a treatment plan for a patient. Various phases in management of oral cancer include accurate diagnosis, appropriate treatment plan, and execution of the advised treatment with relevant reconstruction, rehabilitation, and surveillance. So, to help clinicians in decision-making, there are several guidelines that exist. As these guidelines have a more generalized approach, it is the clinician's knowledge

**Table 82.1** Performance status scale: Zubrod scale and Karnofsky scale


**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_82) contains supplementary material, which is available to authorized users.

Mazumdar Shaw Cancer Center, Bengaluru, Karnataka, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1869

and understanding and experience which will help in tailoring the treatment plan to each individual distinctly. This individualized approach cannot be implemented unless there are multidisciplinary tumor board meetings, which are crucial for clinicians practicing oncology and hence provides teambased practice keeping the patient in mind [2–4]. This is best done before initiating the treatment.

To be able to know the extent of disease and decide the intent and modality of treatment, imaging plays a very important role. Precise imaging information is needed to determine the locoregional extent, erosion, and involvement of underlying bone and marrow space, lymph node involvement and to rule out distant metastasis—especially to the lungs. However the dilemma that most clinicians face is which is the imaging modality of choice for different clinical scenarios. In the following section, we attempt to provide indications of each imaging type available, which probably will help the clinicians in deciding what suits their needs.

Plain radiography is restricted to evaluation of pathological fractures or initial benign lesions. Contrast-enhanced computed tomography (CECT) is considered as the most popular, easily available, and cost-effective diagnostic imaging. It is the imaging modality of choice to know the presence of bone erosion and lymph node characteristic. Bony expansion is usually a feature of slow-growing/benign disease process; however destruction of bone and replacement by the tumor depicts the aggressiveness and hence is a feature of malignant process (Figs. 82.1, 82.2, 82.3 and 82.4).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 82.1** Axial section of contrast enhanced CECT showing an illdefned heterogeneously enhancing mass lesion along the mandibular alveolus involving the central lateral incisors and canines with erosion of body of mandible

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 82.2** Sagittal section of the patient same as Fig. 82.1 to depict the extent of bony erosion and involvement providing a guide for the osteotomy

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 82.3** This is axial section in bony window for exact extent of bony erosion

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 82.4** Axial section—contrast-enhanced computed tomography. A heterogeneously enhanced conglomerate of the lymph nodal mass at left level II with cystic areas highly suspicious of metastatic lymphadenopathy. The mass has partially compressed internal jugular vein and pushed it posterolaterally

Magnetic resonance imaging (MRI) is usually indicated as an adjunct as it has better soft tissue delineation. It is also used for assessing dural invasion (linear or nodular), medullary bone involvement, and perineural invasion. Radiographic assessment of tumor extent is invaluable for treatment planning. In case of tongue cancers, MRI has gained popularity for assessment of tongue cancer especially as it is helpful in identifying tumor thickness, involvement of the contralateral side, and involvement of extrinsic muscles. With recent addition of depth of invasion in the AJCC classifcation for staging, MRI has proven its role. As for buccal mucosa tumors, assessment of masticatory muscles involvement is crucial because it has historically been considered unresectable. However, according to Liao, infranotch lesions are still amenable for resection with favorable oncological outcome.

As oral cancers usually metastasize frst to the lung, preoperative chest imaging is a part of initial pre-operative work-up. This can be in the form of either plain flm or 3D imaging such as computed tomography (CT). Fluorodeoxyglucose positron emission tomography (FDG-PET) scan has emerged as the imaging modality of choice in patient with recurrence and high clinical suspicion for distant metastasis (Figs. 82.5, 82.6, 82.7 and 82.8).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 82.5** The contrast-enhanced T1-weighted MRI images depicting hyperintensity involving the left lateral tongue with extension till the midline and involving tip of the tongue

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 82.6** Axial section of an MRI (T2-weighted) showing multiple lymph node metastasis at level IB

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 82.7** This is the whole body image of PET-CT scan depicting uptake in the multiple areas suggestive of metastatic disease

It is to be noted that any suspicious lesions in PET-CT scan needs to be corroborated with tissue diagnosis (direct or guided) as there are a subset of lesions with false-positive fndings; however, PET-CT is considered to have the highest negative predictive value approaching 100%. Although as per the NCCN guidelines, PET-CT has to be advised for all stage III and IV disease, it is usually reserved for patients with recurrent or second primary disease in a resourceconstrained setting [5, 6]. Tables 82.2 and 82.3 provide imaging considerations in oral cavity tumors.

Baseline follow-up imaging is usually done after 3 months, and CECT has established its role in ruling out recurrence/residual disease. To avoid misinterpretation, it is

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**Fig. 82.8** FDG PET-CT images to show FDG avid lesion in the right lower alveolus and ipsilateral level II lymph nodes along with uptake in the right nasopharynx. All the lesion have a similar standard uptake value (SUV) of 15 corresponding to the metabolic activity

important that the concerned imaging radiologist is familiarized with postoperative sequelae of tissue changes or changes that occur following radiotherapy such as nonspecifc tissue thickening, edema, or fbrosis and various bony and soft tissue reconstruction methods to facilitate interpretation.

Staging the disease is developed to provide ease of communication and helps in understanding the prognosis and planning the treatment. AJCC staging system has been followed for years and provides concise information on size characteristics and extent of primary tumor and involvement of lymph nodes. The recent eighth edition has features like tumor thickness, depth of invasion, and extranodal extension (clinical and pathological).

### **82.3 Category for Oral Cavity Cancer, Eighth Edition Staging Manual**

Table 82.4 provides the categorization for oral cavity cancer [6].

### **82.4 Principles of Surgical Management**

In majority of oral cavity squamous cell cancers, surgery has been the mainstay of treatment, and hence, the need to know intricate surgical aspects has to be emphasized. As there has been improved understanding of disease pattern, biologic behavior of the disease at the molecular level, and the poten-

#### **Table 82.2** Imaging in oral cavity tumors


**Table 82.3** Imaging considerations for various sites


**Table 82.4** Category for oral cavity cancer, eighth edition staging manual [6]: Defnition of primary tumor (T)


or core needle biopsy only

U Metastasis above the lower border of the cricoid

#### **Table 82.4** (continued)


Similarly, clinical and pathological ENE should be recorded as ENE(−) or ENE(+) N suffx Defnition


#### **Defnition of distant metastasis (M)**


tial aggressive nature, the need has arisen for several technical modifcations in this era. Hence as surgeons, we have to evolve and adapt to the required changes to improve outcomes of ablative surgery (oncological and functional) in patients with squamous cell carcinoma of oral cavity.

For early-stage oral cavity cancers, especially tongue, it has been proven that both surgery and radiotherapy/brachytherapy offer similar outcome (single modality). For advanced lesions with extensive disease, multimodality treatment is required; surgery being the primary modality and followed by adjuvant radiotherapy +/− chemotherapy (depending on the histopathological evaluation) has been the standard of care.

#### **82.5 Treatment Decision Algorithm** [14]

Critical decisions which have to be made are as follows:


**Decision 1** Primary intent of treatment: This is the frst and most critical decision-making point. All patients other than those with technically unresectable tumors, distant metastasis, poor performance status, and major comorbidities precluding surgery must be considered for treatment with curative intent. However, it is to be noted that surgical excision with positive margins portends poor prognosis. Palliative care is usually when patient has distant metastasis and given only to relieve symptoms and control spread. This is in the form of chemotherapy, radiotherapy or metronomics.

**Decision 2** Curative modality of treatment: The primary treatment for patients with oral cavity cancers is surgery. However, in selected scenarios, non-surgical treatment may be considered. This includes primary radiotherapy for tumors of the commissure of mouth and lip tumors where surgery can cause signifcant esthetic and functional disability. In addition, signifcant comorbidities that preclude long anesthesia may necessitate the need for primary radiotherapy or chemoradiotherapy. However primary chemoradiotherapy has very limited role in treatment of oral cancers.

**Decision 3** Management of neck in N0 stage: Even with no radiographic evidence of signifcant suspicious lymph-nodes, rate of occult metastasis reaches up to as high as 30% [15]. Presence of lymph node metastasis and the number of lymph nodes involved have a direct relation with the prognosis of the disease; decreasing the overall survival rate by 50%. Moreover, a signifcant subset of metastatic nodes of less than 1 cm can have extranodal extension [16]. This further worsens the prognosis. There is now level I evidence from a randomized control trial, that addressing the neck surgically irrespective of the lymph node status improves overall survival to about 84% when compared to 69% in patients who were selected for wait-and-watch policy [17]. Therefore, almost all the patients with oral cavity cancer should undergo elective neck dissection. A subset analysis of the same study did not show beneft for primary tumors of depth less than 3 mm. This may be considered in selected patients with cancers of lower nodal metastatic prevalence such as lip and buccal mucosa.

**Decision 4** Extent of neck dissection in N+ve oral squamous cell carcinoma: Conventional teaching is that any patients with N+ve neck should undergo modifed radical neck dissection covering levels 1–5. This has been questioned by several observational studies. Large cohort of patients who have undergone radical neck dissection for N+ve disease has showed less than 3% incidence of level V nodes [17]. This also was observed only when there were pathologically positive level IV nodes [18]. There are reports of oncologic safety for clearing level I–III lymph nodes for alveolus and buccal mucosal cancers and to clear level IV in addition to levels I, II, and III lymph nodes in patients with oral tongue cancers as they bore high risk of skip metastasis [19]. It is to be noted that when a patient is found to have pathological nodal metastasis, in general, it is recommended for adjuvant radiation that covers all levels of the neck with additional boost in the levels which are positive for metastasis.

**Decision 5** Indication for adjuvant radiotherapy: Any patients with more than one of the high risk features should be considered for adjuvant radiotherapy.

This includes (1) nodal metastasis without extracapsular extension, (2) perineural invasion, (3) lymphovascular invasion, (4) poor differentiation, (5) close margin (1–5 mm), and (6) depth of invasion over 1 cm.

But the absolute indication for radiotherapy is stage III and IV disease.

**Decision 6** Indication for adjuvant chemoradiotherapy: Meta-analysis of two randomized trials has suggested that in patients with positive surgical margin (<1 mm) and neck nodes with extranodal extension would beneft from adjuvant chemoradiotherapy.

**Decision 7** Best supportive care options: This is an important and critical decision. Once the decision for treatment with palliative intent is arrived at, the goal should be made clear with the treating team of doctors and the patient/ patient attenders. Ambiguity at this stage may result in loss of trust between the treating team and the patient, causing delay in treatment and possible increase in morbidity. Although this decision is made in the multidisciplinary tumor board, it requires series of meetings with the family to convey the treatment goals. It is also essential to appreciate by treatment group that lack of active treatment does not mean stoppage of care, which needs to be provided by the same team till the end. The quality of death is equally important as quality of life.

The role of best supportive care is to palliate the symptoms the patients may have. In this situation, it is essential to balance the morbidity of treatment versus potential beneft the patient may receive. Often one may have ethical dilemma when faced with young patients with locoregionally advanced tumors. In this situation, temptation of surgery should be tempered. One should consider surgery as palliation to alleviate fungating ulcers or to close a cutaneous fstula. The goal of this surgery must be made very clear to the family. It is essential not to give false hope to the family, which will have deleterious consequence in the patient-physician relationship. In patients with good performance status, especially those who have not received previous radiotherapy, one may consider chemoradiotherapy with curative dose, with the goal to obtain durable palliation. In doubtful situations, induction chemotherapy followed by chemoradiotherapy could also be considered. Local radiation or re-radiation to a limited feld may be considered for fungating ulcers. The dose, fractionation, and volume of radiation feld need to be tailored for palliative purpose.

In patients with advanced metastatic disease, one needs to be very selective in recommending systemic therapy as the beneft is doubtful. Chemotherapy with targeted anti-EGFr treatment has shown improved survival up to 4 months, with signifcant morbidity associated with the regimen [20]. An alternate approach is chemotherapy at metronomic dosing regimen, especially the use of methotrexate and celecoxib [21]. Recent evidence of nivolumab, a checkpoint inhibitor, showing improved survival of about 3 months, and acceptable morbidity, is to be considered. However the cost of the treatment is a major deterrent for its wider application. Table 82.5 provides the indications for adjuvant RT and adjuvant CT + RT.



• Bernier J et al. [22]

#### **82.6 Indications for Adjuvant RT and Adjuvant CT + RT**

After various comparative studies, it has been concluded that in adjuvant setting, postoperative IMRT has to be given at dose of 60 Gy in 30 fractions to surgical bed and frst echelon nodal stations and the high-risk regions receive a total dose of 66 Gy. It has to be remembered that for salvage surgery cases, concept of re-irradiation should be explained to the patient. A minimum of 12-month duration gap is required prior to re-irradiation to allow for the spinal cord recovery.

In cases with postoperative histopathological features like extranodal extension or positive surgical margins, patients are treated with concurrent chemoradiation (usually 100 mg/ m2 of cisplatin for a maximum of 6 cycles in India). Indication of chemotherapy as described is usually in adjuvant setting in oral cavity cancers.

However role of chemotherapy as induction therapy is evolving. Chemotherapy usually exerts its cytotoxic effects systemically and hence associated with side effects. The major drawbacks of chemotherapeutic agents used commonly are the adverse toxicities and cellular resistance. In an induction setting, most commonly taxanes, platinum, and 5FU are used as 3 cycle regimen (also refer Chap. 84 of this book on Adjunctive therapy in Oral Cancer).

Tumors of oral cavity which are considered technically unresectable are as follows:


These are considered unresectable not due to surgical technicality but because of the inability to get negative margins and to achieve R0 resection. However, with the superior skills such as endoscopic-assisted surgeries which are associated with less morbidity, and better adjuvant treatment including chemotherapy, an attempt has been made to consider resection of tumors involving muscles of mastication and pterygoid plates especially with the anterior infratemporal fossa involved. Recent studies have shown that surgical resection of these tumors along with adjuvant treatment has shown survival beneft. Also studies from Tata Memorial Hospital, India have shown better outcome in patients who have undergone surgical resection following neoadjuvant chemotherapy.

#### **82.7 Principles of Ablative Surgery**


The surgical approaches for tumors of oral cavity depends primarily on the site of tumor (anterior versus posterior), its size, and its proximity to bone (maxilla or mandible). The various approaches frequently used for oral cavity cancers are shown in Figs. 82.9, 82.10, 82.11, 82.12, 82.13, and 82.14 (Also refer Chap. 85 of this book on Access Surgeries and Osteotomies of the Maxillofacial Region).

Types of mandibulotomy is shown in (Figs. 82.15, 82.16a, b) shows marginal mandibulectomy and segmental mandibulectomy.

#### **82.8 Sub-Site-Wise Surgical Management**

#### **82.8.1 Tongue and Floor of Mouth**

The tongue is a muscular organ which is composed of intrinsic and extrinsic muscles and divided anatomically into the oral tongue (falls in oral cavity cancers) and base of tongue (BOT, sub-site of oropharynx). The tongue is innervated by the hypoglossal nerve, and vascularity is by lingual artery (branch of external carotid artery). Pathway of tumor spread from the oral tongue can be into the foor of mouth, mandible, or/and base of tongue via local extension, the lingual septum being the barrier to tumor spread. For tumors abutting the mandible, marginal mandibulectomy is indicated for negative surgical margin encompassing the tumor and at the same time preserving the mandibular continuity. Segmental mandibulectomy is usually done when there is mandibular erosion or paramandibular spread. Anterior segmental mandibulectomy is more commonly indicated in foor of the mouth cancers.

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**Fig. 82.9** Lip split incisions; (**a**) midline lip split (straight), (**b**) midline lip split with Z-plasty; (**c**) angle/commissure lip split; (**d**) straight midline with chin contour; (**e**) straight midline with chin contour and Z-plasty at vermilion and submental region

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**Fig. 82.10** Pictorial representation of excision of lesionally per-orally. This is usually indicated for T1–2 lesion in patients with adequate mouth opening

Lingual artery is an end artery, and hence clinicians have to be careful in resections involving more than two-thirds of tongue mass as this may jeopardize the vascularity and utmost care to be taken to preserve the neurovascular bundle.

There is a recent concept of compartment resection in patients with infltrative disease where the adjacent extrinsic musculature and neurovascular bundle is excised in continuity to ensure negative margins. This was proposed by Calabrese [23], and all cases underwent access mandibulotomy; hence it is not commonly followed. Tumors of foor of the mouth are usually infltrative and lymph node metastasis is seen bilaterally. According to Byers, the rate of lymph node skip metastasis at level IV is observed in about 10–15% cases. According to the study by Kowalski [24], tumors of foor of the mouth, tongue cancers crossing the midline, and advanced stage of the disease have a propensity of developing contralateral lymph node metastasis.

**Fig. 82.11** Weber-Ferguson incision for tumors of maxilla not amenable to per-oral excision and not requiring infratemporal fossa access. The upper cheek fap is raised as shown

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**Fig. 82.12** A lower midline lip split incision continued and transverse neck skin crease incision followed by raising of a lower cheek fap. This gives the best access to infra-temporal fossa. The periosteum to be left on the mandible to preserve its periosteal blood supply. The mental neurovascular bundle has to be sacrifced

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#### **82.8.1.1 Surgery**

Wide local excision (WLE)/adequate glossectomy procedure with adequate surgical margins has been the procedure of choice for early tongue cancers, and this is amenable with per-oral approach. Before planning resection, thorough knowledge about the extent of lesion is important, and palpation of induration provides a guide for the same. Ideal margin for resection of tumour is all 1–1.5 cm all around. Usually it is the deep soft tissue margin which is prone for being close or positive, and this can be avoided by palpation method. In many institutions, it is a useful practice to ligate the lingual artery in the neck before performing WLE for

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**Fig. 82.13** This picture depicts access mandibulotomies for tumors situated in the posterior tongue. The other alternative is pull through approach

**Fig. 82.15** Depiction of various types of access mandibulotomies

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**Fig. 82.14** Visor fap provides best access for total and subtotal glossectomy

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©Association of Oral and Maxillofacial Surgeons of India

adequate bleeding control and clean surgical feld. The resulting defects of adequate glossectomy for early lesions are usually closed primarily avoiding tethering of the tongue. Excisional biopsy for suspicious lesions is highly discouraged even if the lesion is about 1 cm.

Moderately advanced cancers of the tongue and foor of the mouth (T2–T3) warrant classical hemiglossectomy which sacrifces the tip jeopardizing the tongue mobility resulting in compromised speech and swallowing. Majority of these tumors are excised by combinations of per-oral and pull-through approaches, without the actual need for lipsplit or access mandibulotomy. The pull through technique helps in avoiding positive posterior margins as the resection is done under direct vision. All these patients require reconstructive surgery (lining or bulk), along with longterm tracheostomy and feeding tube (ryles tube/PEG) dependence. Free-fap reconstructions have become inevitable following resection of tongue cancers. Locally advanced (T4a) cancers (tumor depth > 20 mm, restricted mobility and hypoglossal palsy) of tongue warrant total glossectomy or near-total glossectomy. Standard total glossectomy procedure involves complete removal of anatomical tongue from mandible to hyoid and from the tip of the tongue upto the vallecula.

The following a is brief outlay of surgical steps: anterior belly of digastric muscle is frst divided through the cervical neck incision followed by intra-oral crevicular incision. Then the genioglossus, geniohyoid is divided from the genial tubercle and mylohyoid muscle from the mylohyoid line from the mandible. At the contralateral retromolar region come the division of buccopharyngeal fascia, styloglossus muscle, and the palatoglossus muscle and incision at the vallecula. The same steps are repeated on the other side for total glossectomy. However in near-total/subtotal glossectomy, base of the tongue of uninvolved side is preserved. It is the extent of excision of the base of tongue which determines the postoperative swallowing function.

Tongue and the FOM lesions involving or abutting mandible pose a unique challenge. Resecting the segment of mandible increases morbidity and reconstructive challenge by many times. In such situations an attempt should be made to preserve the mandible whenever possible.

Removal of the level V lymph node is reserved in situations when level IV or V is involved or in N3 nodal disease. According to Kowalski et al., the indications for addressing contralateral lymph nodes are lesions of the tongue crossing the midline, foor of the mouth tumors, and locally advanced T3 and T4 tumors [24].

Reconstruction of the tongue requires a soft tissue fap with large volume to provide the adequate bulk which in turn is believed to aid in swallowing. The drawback of a reconstructed tongue is the impaired mobility resulting in compromised speech. The most commonly used fap is radial forearm free fap and anterolateral thigh free fap. The other uncommon examples for free tissue transfer are lateral arm fap, gracilis fap, and local fap such as FAMM fap and submental fap.

Reconstruction of tongue defect using radial forearm free fap (Figs. 82.17, 82.18, 82.19, 82.20 and 82.21).

Reconstruction of tongue defect with local fap: facial artery myomucosal fap (Figs. 82.22, 82.23, 82.24 and 82.25).

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**Fig. 82.17** Squamous cell carcinoma of left lateral border of the tongue with induration extending 1 cm short of midline not involving foor of mouth

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**Fig. 82.19** Completed left modifed radical neck dissection

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**Fig. 82.18** Post-surgical defect following left hemiglossectomy and left marginal mandibulectomy

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**Fig. 82.20** Left radial artery forearm free fap harvested for the defect

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**Fig. 82.21** Radial forearm free fap inset into defect and anastomosed to left facial artery and tributory of left internal jugular vein

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**Fig. 82.22** Tongue defect following wide local excision of left lateral border tongue squamous cell carcinoma

#### **82.8.2 Buccal Mucosa**

#### **82.8.2.1 T1/T2 Lesions**

**Surgical Steps: For Early Buccal Cancer** Per-oral approach is adequate. It is important to ensure oncologic

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**Fig. 82.23** Harvesting of facial artery myomucosal fap (FAMM)

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**Fig. 82.24** FAMM fap tunneled into the defect and reconstructed

completeness and appreciate depth. Inadvertent injury to the buccal branch of facial nerve and to the parotid duct should be avoided. Facial artery, facial vein, and parotid duct (if encountered or injured) should be ligated. Mucosal incision around the lesion, with adequate margin, taking the buccinator muscle in specimen forms the deep soft tissue margin. These defects can be reconstructed with split thickness skin grafts/buccal pad of fat/local faps such as nasolabial fap.

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**Fig. 82.25** Closure of the donor site

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**Fig. 82.26** Locally advanced T4a, left buccal mucosa lesion requiring composite resection with excision of the overlying involved skin

**Advanced T3/T4 Lesions (Lesions with Skin Involvement/ Bone Involvement/Involvement of Muscles of Mastication)** Pre-operative clinical examination revealing a subtle skin puckering and imaging studies shows stranding

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**Fig. 82.27** Defect following composite resection and modifed radical neck dissection; this defect was reconstructed with anterolateral thigh free fap

of subcutaneous fat that is the early sign of skin involvement. If buccal space involvement is suspected, then buccal fat pad should be included in the specimen.

These advanced lesions require full-thickness cheek resection. The planning of incision may be a midline lip split or angle split, both of which will help in raising a lower cheek fap or when overlying skin is involved, an incision around the skin involved in continuity with the neck dissection incision. The muscle of mastication involvement warrants infratemporal fossa clearance (Figs. 82.26, 82.27 and 82.28).

#### **82.8.3 Gingivobuccal Sulcus**

Gingivobuccal sulcus (GBS) tumors are tumors occurring in the upper or lower GBS, usually seen to abut the bone adjacent (Fig. 82.29). These occur almost exclusively in Southeast Asia due to high incidence of chewing tobacco use. Due to the high propensity for local invasion and close proximity of bone, skin, and masticator space, presentation is often advanced, and outcomes are poor. If there is superfcial erosion of bone or if the lesion is abutting the mandible, then the resection should include marginal mandibulectomy. Superfcial cortical erosion in alveolar tumors is not considered as T4 lesion, and marginal mandibulectomy may still suffce. Although MRI is consid-

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**Fig. 82.28** Excised specimen in toto (Same case shown in Figs. 82.26 and 82.27)

ered most sensitive imaging modality to determine extent of bony involvement, periosteal stripping is by far the best method to determine extent of bony erosion and helps in decision-making regarding extent of mandibulectomy. GBS tumors usually present at an advanced stage with gross mandibular erosion, paramandibular spread, or overlying skin involvement (skin involvement is never seen in the masseter region as it is a tumor barrier). These fndings preclude the use of marginal mandibulectomy, and hence patients often require segmental mandibulectomy and bony reconstruction.

#### **82.8.4 Retromolar Trigone Carcinoma**

Retromolar trigone tumors are rare but more aggressive malignancies with poorer outcome. Higher incidence of local recurrence has been reported in squamous cell carcinoma of the retromolar trigone (RMT) and posterior GBS carcinomas. This is attributed to to its higher propensity of infratemporal fossa (ITF) and pterygomandibular fssure involvement. Due to restricted mouth opening at the time of presentation, thorough clinical examination is hindered. For both oncologic and anatomic reasons, tumors with mandibular invasion are best managed surgically by segmental mandibulectomy including coronoid process of the mandible.

The reason to preserve condyle is as follows: (a) it may be used for secondary reconstruction, and (b) as the condyle lacks medullary bone, it does not act as a pathway of spread and hence can be oncologically safe to preserve it.

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**Fig. 82.29** Classic example of a gingivo buccal tumor abutting the adjacent mandible

As a large proportion of the RMT tumors involve both the upper and lower jaw (Fig. 82.30), excision of ramus of mandible in the form of subsigmoid marginal mandibulectomy with at least an upper alveolectomy and ITF clearance (anterior ITF comprising masseter and medial pterygoid with or without pterygoid plates) is required. Selective neck dissection comprising of level I–V lymph nodes is usually performed electively for all stage cancers for purpose of staging.

#### **82.8.5 Hard Palate**

Tumors of the hard palate are less common when compared to tumors of the mandible, tongue, or buccal mucosa and are often of minor salivary gland etiology. Premaxilla provides support for the nose and midface; lesions involving anterior alveolus and hard palate will require bony reconstruction to prevent midface deformity. Lesions of the posterior alveolus and hard palate have a higher tendency to locally invade the orbital foor and skull base or through various neurovascular bundles (greater palatine foramen, sphenopalatine foramen, palatovaginal canal).

Lymph node involvement is very rare for salivary neoplasm of the palate, and neck dissection is reserved only for node-positive disease. However, maxillary alveolar carcinoma has a high propensity for occult lymph node metastasis

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**Fig. 82.30** Left retromolar trigone squamous cell carcinoma extending to involve lingual surface of mandible, soft and hard palate ipsilaterally

(15–20%), and also in patients where neck is not addressed, they tend to present with nodal recurrences which are not salvageable in two-thirds of the cases; hence it is wise to consider elective neck dissection. The other point worthwhile and to be noted is that perifacial group of lymph nodes have to be cleared for effective disease control for the upper alveolus (Figs. 82.31, 82.32, 82.33 and 82.34).

#### **82.8.5.1 Brown's Classifcation System for Maxillary Defects** [25] (Fig. 82.35)

#### **Vertical Component**


**Horizontal Component** I, unilateral alveolar maxilla and resection of the hard palate;

(a) resection of less than or equal to half of the alveolar and hard palate, not involving the nasal septum or crossing the midline;

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**Fig. 82.31** Minor salivary gland tumour of the hard palate

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**Fig. 82.32** Defect following partial maxillectomy

(b) resection of the bilateral alveolar maxilla and hard palate, including a smaller resection that crosses the midline of the alveolar bone, including the nasal septum; and

(c) removal of the entire alveolar maxilla and hard palate.

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**Fig. 82.33** Specimen in toto

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**Fig. 82.34** Defect reconstructed with conventional obturator placement

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**Fig. 82.35** Brown's classifcation for maxillectomy defects

#### **82.8.6 Lip Carcinoma**

Squamous cell carcinoma of the lip is most frequently associated with sun exposure as the risk factor. Lower lip is more commonly involved than the upper lip. Submental and submandibular nodal basins are the primary echelon drainage pathways; regional nodal metastasis occurs in only 10% of patients. Full-thickness excision with up to 1 cm margin is necessary. Lesions that involve less than one-third of the lip are managed with simple wedge excision and primary closure and hence offer acceptable oncologic and reconstructive results. For lesions larger than one-third but less than two-thirds, Abbe-Estlander or



Karapandzic fap can be utilized (refer Chap. 86 on Soft tissue reconstruction of the Maxillofacial Region). For defects more than two-thirds, free tissue transfer is preferred to achieve better cosmetic result and avoid microstomia and oral incompetence. To ensure oral competence, adjunctive procedures such as fascial sling, palmaris longus sling, or temporalis muscle sling can be used along with the adynamic soft tissue fap.

Table 82.6 describes the treatment modalities of use in oral cancer.

#### **82.8.6.1 Management of the Neck in Oral Cavity**

#### **Introduction**

Although skip metastasis can occur, lymph node metastasis usually follows a predictable fashion from the frst echelon nodes to the second echelon nodes. Tumors of the oral cavity most commonly drain to levels I (submental and submandibular group) and level II (upper jugular group) in the neck. Level IA is between the two anterior belly of digastric muscle, and level IB is between anterior and posterior belly of digastric muscle on either side. The submental triangle drains the anterior portion of the oral cavity and hence can get involved in the tumors of the incisor region, the anterior foor of mouth, or anterior mandibular gingival/alveolar cancers. The level II nodes are found between the level of the hyoid bone inferiorly and anteriorly, the posterior belly of the digastric muscle superiorly, and the posterior border of the sternocleidomastoid muscle (SCM) posteriorly. In the jugular chain, the level III lymph node station is demarcated inferiorly by the omohyoid muscle as it crosses the internal jugular vein (IJV) and contains the mid-jugular lymph nodes particularly the prominent omohyoid node lying in close relationship to the muscle. Level IV (between the omohyoid muscle and the transverse cervical vessels, medially bound by the IJV) and V (between the posterior border of SCM and anterior border of trapezius muscle, further divided into levels A and B by the spinal accessory nerve) nodes are very rarely directly involved by early initial spread of oral SCC. In addition to these classical patterns of spread, buccal cancers may present with parotid nodes, and the posterior maxillary alveolus/hard palate may spread initially to retropharyngeal nodes. Tumors involving/ crossing midline and tumors of the foor of the mouth generally require bilateral neck dissection.

#### **82.9 Evaluation and Diagnosis**

Evaluation of neck disease for the purpose of staging is best done by USG-guided FNAC, it being both highly sensitive and specifc, simple, and cost-effective but observer dependent. Although palpation is most commonly employed, it has a very low accuracy ranging between 50 and 65%. The limitations of palpation method are obese patients or patients with previously treated necks; examination is more diffcult. Imaging with CT scan or MR has been said to improve accuracy for metastatic neck disease to approximately 90%. Chaukar et al. found contrast-enhanced CT to give better concordance with histology in the N0 neck than either US or PET/CT.

#### **82.10 Management**

Evolution of neck dissection [26, 27]:


#### Technique:


fatty tissue between these structures, the deep limit of dissection being the prepectoral fascia. At any given point on time tractional injury to the SAN has to be avoided.

• This is followed by release of the fascia and tissue along the posterior border of SCM till the clavicle inferiorly;

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**Fig. 82.36** Incision marking for selective neck dissection

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**Fig. 82.37** Raising of subplatysmal fap

mylohyoid muscle retracted inferiorly and lateral border of IJV identifed. Care is taken to preserve deep cervical plexus. Now the level II–IV tissue is retracted anteriorly and peeled off the IJV and continued in the anterior triangle of the neck till the midline, preserved the superior thyroid vessels and tributary of IJV.

• Level IIB is dissected between the posterior belly of digastric and postero-superior to the SAN, posterior limit being SCM.

This completes the selective neck dissection (Figs. 82.36, 82.37, 82.38, 82.39, 82.40, 82.41, 82.42, 82.43, 82.44 and 82.45).

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**Fig. 82.38** Mobilization of submandibular salivary gland for level I dissection; also seen is isolation of facial vessels

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**Fig. 82.39** Completed Level Ib dissection, boundaries well appreciated

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**Fig. 82.40** Exposed SCM, greater auricular nerve, and external jugular vein can be seen over the SCM

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**Fig. 82.41** Spinal accessory nerve exposed in level II region

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**Fig. 82.42** Level II–IV Lymph node dissection mobilized over the IJV

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**Fig. 82.43** Completed selective neck dissection (level I–IV) preserving sternocleidomastoid (SCM), spinal accessory nerve (SAN), internal jugular vein (IJV)

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**Fig. 82.44** Intraoperative picture depicting right infrastructure maxillectomy, right hemimandibulectomy, modifed radical neck dissection (level I–V) preserving only internal jugular vein with suction drains in situ

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**Fig. 82.45** Composite resection with left hemimandibulectomy and selective neck dissection (Level I–IV) preserving the non-lymphatic structure

#### **Table 82.7** Complications of neck dissection [29]


#### **82.11 Complications of Neck Dissection**

Table 82.7 provides a comprehensive view of the complications arising from neck dissection [29].

**Disclosure** Authors have no conficts of interest to disclose.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

**83**

## **Sarcoma of the Maxillofacial/Head and Neck Region**

D' Souza Jacob and Boyapati Raghu

#### **83.1 Introduction**

Sarcomas are uncommon malignant tumours with incidence of less than 5% of all head and neck malignancies in adults [1, 2]. They are more common in children, accounting for 30% of head and neck sarcomas [2, 3]. They arise from either soft or hard tissue mesenchyme cells. There is a male predominance and presentation is usually in the third and fourth decade of life in 70% of cases [4, 5].

Metastasis at initial presentation is seen in only 10% of patients, usually from high-grade primary lesions [6–8]. Despite this, prognosis tends to be poor, partly due to the proximity of vital neurovascular structures leading to diffculty in obtaining adequate surgical clearance. Moreover, majority of the sarcomas are poorly differentiated, a poor prognostic marker [9].

Sarcomas tend not be related to the use of tobacco and alcohol. Predisposition to the development of sarcomas is seen in some conditions [4, 8, 10]. Notable examples include association of osteosarcoma in patients with Li-Fraumeni syndrome, angiosarcoma with chronic lymphoedema and Kaposi's sarcoma with HIV infection. Additionally, exposure to chemicals such as vinyl chloride is well-recognised risk factors [10].

#### **83.2 Classifcation**

Broadly speaking, sarcomas can be classifed into two categories: soft tissue and hard tissue (bone and cartilage) sarcomas. This, however, is an oversimplifcation since precise classifcation is fraught with signifcant diffculties. For example, fbrosarcoma and malignant fbrous histiocytoma are soft tissue sarcomas that arise in hard tissues [11, 12]. In contrast, chondrosarcomas are classifed as soft tissue

D. S. Jacob (\*) · B. Raghu

Maxillofacial Unit, Royal Surrey County Hospital, Guilford, UK e-mail: dsouzaj@icloud.com; raghusurgdent@doctors.org.uk

tumours. Additionally, some hard tissue tumours display extraosseous extension [1–3].

Ten or more main histological types and even more subtypes of sarcomas are described. Osteosarcoma, angiosarcoma and malignant fbrous histiocytoma make up the majority tumours in adults. In children, rhabdomyosarcoma is the most common sarcoma [1–3].

#### **83.3 Staging**

Soft and hard tissue sarcomas are staged using different systems (Tables 83.1 and 83.2). The American Joint Committee on Cancer (AJCC) and the International Union Against Cancer (UICC) staging systems are used in most centres [13]. Other systems may be used in selected cases such as the Memorial Sloan Kettering system [14].

#### **83.4 Natural History and Prognostic Factors**

Head and neck sarcomas tend to show poorer response to treatment compared to sarcomas affecting the trunk and extremities [5, 6]. This is despite the low rate of lymph node metastasis at presentation (less than 10% of cases) and the modern multimodality treatment with surgery, radiotherapy and chemotherapy [4, 5]. Local and regional nodal recurrence is common and is more likely to result in death than distant metastatic spread [5, 8, 10].

The reasons for treatment failure resulting in disease recurrence are multifactorial. Adequate surgical margins are hard to achieve given the complex anatomy of the maxillofacial and the skull base regions (Fig. 83.1). The morbidity of radical resections is unacceptable, both functional and aesthetic. This is especially true for primary tumour larger than 10 cm at presentation [8, 9, 11]. Resections aimed at minimising morbidity risk positive or involved surgical

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1893

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_83

**Table 83.1** TNM/UICC classifcation of soft tissue sarcomas



**Table 83.2** TNM/UICC staging of bone sarcomas


margins and are an independent predictor of treatment failure and hence survival [5, 7, 8]. The grade of tumour is another prognostic factor. For example, the 5-year survival rates for high-grade tumours such as malignant fbrous histiocytoma, osteosarcoma and angiosarcoma are in the range of 60%. This is in contrast with low-grade tumours such as chondrosarcoma or dermatofbrosarcoma protuberance which show survival approaching 100% at 5 years [8, 9, 15]. There is optimism, however, with modern combined treatment modalities, for example, patients with rhabdomyosarcomas are showing better survival outcomes. Finally, sarcomas arising in previously irradiate tissues have poor prognosis due to a multitude of factors: delayed diagnosis; high-grade, inadequate surgical margins; limited option of adjuvant radiotherapy; and lack of proven chemotherapy regimens [10, 16, 17].

It is important to interpret the published treatment outcomes and survival rates with caution. Comparison between institutions is unreliable due to different study population, histological subtypes and follow-up regiments. Moreover, lack of standardisation in reporting leads to institutional bias of a selected treatment modality. Reported overall survival for bone sarcomas approach 80% at 2 years and 74% at 5 years [18, 19]. Radiation-induced sarcomas perhaps have the worse survival outcomes, as low as 25% at 5 years [19, 20].

#### **83.5 Principles of Treatment**

It is diffcult to draw frm treatment guidelines for head and neck sarcomas because they are a rare group of heterogeneous tumours. The treatment philosophies vary between institutions due to multitude of factors as discussed previously in this chapter. Meta-analysis outcomes are therefore controversial and unreliable to draw frm conclusions. Furthermore, there are no randomised controlled trials [20, 21]. Despite this, there is consensus that early surgical resection with appropriately

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 83.1** (**a, b, c**) Osteosarcoma of the right posterior maxilla. Photograph showing osteosarcoma of the right maxilla. The extent of bone destruction from the tumour is seen in the scan. The resected specimen confrms the loss of the hemi-maxilla

timed adjuvant therapies can help improve outcomes. Needless to say, the role of multidisciplinary input/tumour board is vital.

Surgical resection of the tumour is the favoured primary treatment modality for patients with sarcomas of the hard tissues [22, 23]. Surgery is often preceded by chemotherapy on a neoadjuvant protocol [19, 22, 23]. The intention is to reduce tumour bulk and hence morbidity by minimising tissue loss. Elimination of micro-metastatic disease, mainly pulmonary deposits, is of added beneft. The role of adjuvant radiotherapy is limited to patients with positive surgical margins who often are not candidates for further resection [19, 24]. Further resections may not be feasible due to anatomical complexity or in those who have undergone complex reconstruction. Note should be made of the evolving role of radiotherapy in Ewing's sarcoma.

The size of the tumour at presentation often restricts the use of surgery in patient presenting with soft tissue sarcoma. Adjuvant radiotherapy is an indication when the resection margins are positive; the tumours are of intermediate or high grade and in cases of recurrent disease [12, 16, 24, 25]. The feasibility of introducing neoadjuvant chemotherapy or preoperative radiotherapy should be considered with diligence in patients with advanced disease at presentation with a view to reduce morbid resections [25, 26]. When surgery is not feasible, the role of palliative radiotherapy alone or in combination with chemotherapy should be considered.

#### **83.6 Principles of Surgery**

#### **83.6.1 Hard Tissue Sarcomas**

There is a consensus that achieving tumour-free zone of tissue at the resection margins maximises the chance of cure. However, what defnes adequate margin remains debated. The current recommendation is resection of the tumour with a 2–3 cm macroscopic margin in patients who receive neoadjuvant chemotherapy aiming to sterilise the microscopic deposits around the main body of the tumour [24– 28]. It is important to plan the resection on scans obtained prior to the neoadjuvant chemotherapy. This is because both the tumour-killing effect of the neoadjuvant chemotherapy and tissue shrinkage are unpredictable. Furthermore, one should aim for compartmental excision (Fig. 83.1) that allows for removal of all potentially involved structures beyond the radiographic margins such as intra-osseous extension of the tumour via marrow spaces [2, 19, 24]. Although this approach is radical, for instance, resection of the hemi-mandible to include disarticulation of the condyle in ramus tumours, the chance of surgical clearance can be maximised to 85% or greater [2].

#### **83.6.2 Soft Tissue Sarcomas**

Similar to hard tissue sarcomas, adequate surgical margins predict survival outcomes, both disease-free and overall survival. The recommendation is for 1–3 cm macroscopic margins [24, 29, 30]. Achieving this may be limited due to anatomical constrains and an infltrative pattern of tumour spread that tends to characterise soft tissue sarcomas. One published series reported adequate surgical clearance in 85% of osteosarcomas vs. 64% soft tissue tumours [2]. The 2-year overall survival estimate for bone tumours (51 patients) was 91% vs. 67% for soft tissue tumours (50 patients) [2]. The 5-year overall survival estimates were 73 and 56%, respectively. These results were statistically signifcant. Other series with different patient cohort have reported 5-year overall survival rates of 74 vs. 57% for bone and soft tissue sarcomas, respectively [31, 32].

#### **83.7 Clinical Assessment**

Patients present with a wide range of signs and symptoms. These may range from indolent lumps to rapidly growing and locally destructive lesions (Figs. 83.1 and 83.2). Pain

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 83.2** (**a**, **b**, **c**) Osteosarcoma of the right posterior mandible. Plain radiograph showing tumour destruction of the right posterior mandible. A fbula free fap and dental implants are used for rehabilitation

is variable and there is a tendency for nocturnal bone pain [1, 4].

There may be a mass at the primary site, ulceration, sensory change affecting the skin or the mucosa, proptosis, epistaxis or nasal discharge, loosening of teeth and unexplained bleeding.

Involvement of the skull base by direct extension can lead to focal neurology. Metastatic lesions can present with a neck mass. Systemic symptoms tend to be non-specifc such as malaise, loss of weight and appetite [8, 23].

#### **83.8 Investigations**

Magnetic resonance imaging (MRI) is usually the preferred investigation for primary lesions [30, 33]. They provide information regarding the nature of the primary tumour (solid, cystic, presence or absence of calcifcations, internal vascularity, etc.). The relationship of the tumour to adjacent tissues can be accurately defned; this helps plan tumour resection [22, 34, 35]. Computer tomography (CT) scan of the facial bone may be used to complement the MRI scan, especially in patients requiring hard tissue resection and reconstruction (Figs. 83.1 and 83.2). The use of composite faps with 3-D reconstruction with prefabricated plates is increasingly used in several centres [36, 37]. The use of dental implants has signifcantly improved outcomes following composite reconstructions (Fig. 83.2). CT scans of the thorax and upper abdomen complete the staging investigations. There is an evolving role for positron emission tomography (PET), both in the initial staging of the disease, the response to treatment and tumour surveillance [38, 39]. Blood tests include comprehensive baseline tests (full blood count, renal and bone profle) and serum alkaline phosphatase. Additional tests may be necessary, often dictated by individual patient profles. Biopsy for tissue diagnosis must include an appropriate sample that in addition to routing staining provides tissue for immunocytochemistry [4, 12].

#### **83.9 Osteosarcoma**

Osteosarcomas are the commonest sarcomas of the bones in adults, representing 1% of all head and neck cancers. They do not show sex predilection. The peak incidence is between 20 and 30 years. However, tumours arising in area of Paget's disease of the bone are seen in older patient 60–70 years of age [25–27]. The mandible is the most frequently affected site, especially the angle/ramus region. In the maxilla, the tumour has a predilection to the alveolar ridge and sinus foor. Notable risk factors include chromosomal abnormalities (deletion of 13q14), germ line mutations (Li Fraumeni syndrome) and dysplasia of bone (Paget's disease and fbrous dysplasia) [25–28]. In some instances, these tumours arise in irradiated bone or de novo.

Patient may present with asymptomatic intra-oral mass, loose teeth and toothache.

Destructive lesions can cause soft tissue cheek swelling, sensory change, proptosis, nasal discharge or bleeding.

Three histological subtypes of osteosarcoma are recognised, namely, osteoblastic, chondroblastic and fbroblastic variants [31, 39].

However, myxoid pattern is the norm (Fig. 83.3). The chondroblastic variant shows binucleated cell characteristic of the lesion (Fig. 83.4) The degree of differentiation classifes them as stage I (well-differentiated and low-grade) to stage IV (poorly differentiated and high-grade). Regional neck metastases at presentation are rare, seen in less than 10% of patients at presentation. Distant metastases are seen in up to 30% of patients at presentation, mostly pulmonary [23, 27, 31]. On rare occasions, patients may present with rapidly progressive, fatal multifocal disease. Imaging reveals local bone. The well-documented fnding of subperiosteal bone formation (Codman triangle) is uncommonly seen in head and neck lesions.

Whilst surgery, radiotherapy and chemotherapy are offered as single or multimodality treatments, wellestablished treatment regimens are lacking in consensus. Various drug combinations have been tried and tested, leucovorin, Adriamycin, cisplatin, ifosfamide and cyclophosphamide, with unpredictable response. One study has shown 2- and 5-year overall survival rates of 100 and 67%, respectively, in those treated with neoadjuvant chemotherapy and surgery. This compares favourably with patient treated with surgery alone showing poorer 2- and 5-year overall survival rates of 66 and 41%, respectively [19, 23, 31]. The role of

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 83.3** Osteosarcoma-myxoid variant. H&E section of an axial slice through the masseter (far left), ramus of the mandible, tumour, medial pterygoid and palatal mucosa (far right bottom corner)

1898

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 83.4** Osteosarcoma-chondroblastic variant. Photomicrograph showing binucleated cells, characteristic of the chondroblastic type

adjuvant radiotherapy is applicable in patients with inadequate or positive surgical margins; however, doses in excess of 60Gy are necessary given their radio-resistant behaviours [8, 16, 31].

In addition to high-grade disease and large tumours at presentation, some additional factors have prognostic signifcance. For example, the expression of the p-glycoprotein confers multidrug resistance negatively impacting on prognosis. Osteosarcomas arising in Paget's disease and elevated alkaline phosphate levels have poorer prognosis [9, 25, 27, 32].

#### **83.10 Malignant Fibrous Histiocytoma**

Malignant fbrous histiocytoma is the commonest soft tissue sarcoma affecting the trunks and extremities. However, it is rare in the head and neck region, with less than 3% occurring here. It shows a male predilection with a 2:1 ratio and mostly seen between 40 and 60 years of age. The commonest subsite is the sinonasal tract. There is a strong link to ionising radiation exposure [11].

Histology shows highly pleomorphic fbroblasts mixed with abnormal histiocytes in a storiform pattern with a background dense infammation (Fig. 83.5). Phagocytised neutrophils with large nuclei/nucleoli are commonly seen. Necrosis is an uncommon feature, but bizarre giant cells or atypical mitotic fgures can be seen on most occasions [30, 34, 40]. The commonest subtype is pleomorphic; less common are giant cell and myxoid types. Immune positivity is seen with α-1-antichymotrypsin, vimentin and Ki-67 [11].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 83.5** Malignant fbrous histiocytoma. H&E section showing highly pleomorphic tumour cells with atypical mitotic fgures amidst dense acute infammation

Wide surgical resection is the primary treatment, with consideration given to adjuvant chemoradiotherapy [17, 23]. Whist local recurrence is the norm, regional metastases to lymph nodes are rare. Positive margins predict for treatment failure locally and distant spread, usually to the lungs and liver [23, 33].

#### **83.11 Liposarcoma**

Although liposarcomas are second most common soft tissue tumours, less than 5% occur within the head and neck region. They show a slight male predominance, most commonly presenting between the ages of 30 and 60. Majority arise de novo rather than developing in a lipoma [24]. Patient may demonstrate risk factors such as repeated trauma, irradiation or genetic abnormality (NF-1 gene). The histological behaviour varies from high-grade (pleomorphic, round) to lowgrade (myxoid) tumours. The myxoid variant shows lipoblasts arranged within a chicken-wire vascular network in a dense stroma (Fig. 83.6). The pleomorphic type shows signifcant numbers of highly atypical fat cells along with lipoblasts (Fig. 83.7). The epithelioid variant can be confused with carcinoma [40].

Whilst surgery remains the primary treatment modality, the role of adjuvant radiotherapy should be considered in patients with high-grade lesions and large tumours with positive resection margins. Published literature supports the use of adjuvant radiotherapy in reducing local recurrence from 60 to 40% [19, 20, 24].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 83.6** Liposarcoma myxoid variant. H&E section showing myxoid tumour with lipoblasts arranged within a chicken-wire vascular network amidst dense myxoid stroma

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 83.7** Liposarcoma pleomorphic variant. H&E showing atypical adipocytes along with pleomorphic lipoblasts

#### **83.12 Rhabdomyosarcoma**

These are predominantly childhood tumours, usually affecting those below the age of 12 years [2, 4, 5]. They show slight male predilection. In contrast to adult sarcomas, up to half of all rhabdomyosarcomas occur in the head and neck sites. The favoured subsites are the orbits, the nasopharynx and the temporal bones [15].

Histologically, at least 70% of the tumours are of embryonal subtype; less commonly, the alveolar subtypes are seen (Fig. 83.8). Immune positivity to desmin, myoglobin and actin is well documented (Fig. 83.9). Cells show fnely granular eosinophilic cytoplasm with cross striations with enlarged nucleus. More differentiated tumours may show elongated rhabdomyoblasts and occasional giant cells. Defnitive diagnosis is based on myogenesis, multinucleated myoblasts, individual tumour cells with cross striations and dense eosinophilic cytoplasm [41].

Prognostic indicators include the location of the primary, age at presentation and metastatic disease. The survival rates have shown signifcant improvement: 71% in 2001 vs. 25% in the 1970s [15, 23, 31]. The orbital tumours show the best prognosis with 5-year survival rates exceeding 90% in children [15]. This contrasts with poor survival rates in adults at approximately 30%.

#### **83.13 Chondrosarcoma**

Chondrosarcomas are malignant tumours of the bone or cartilage, and 10% are located in the head and neck [2, 8]. The larynx is the most commonly involved subsite, closely fol-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 83.8** Rhabdomyosarcoma pleomorphic variant. H&E section showing high-grade sarcoma with pleomorphic rhabdomyoblasts

lowed by the maxilla and mandible. The peak incidence is 30–50 years. At least 80% arise de novo. Secondary tumours arise in abnormal bone in conditions such as Paget's disease and fbrous dysplasia [40]. Rarely, extraosseous tumours are seen due to cartilaginous differentiation of primitive cells. Patient's symptoms depend on location and the extent of local tissue destruction. Despite slow initial progression, multiple metastases can develop rapidly [26]. Radiographic examination may show sunray speculation.

The degree of differentiation can range from well to poorly differentiated tumours. The common subtypes include myxoid and mesenchyme [26]. It is not uncommon for them

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 83.9** Rhabdomyosarcoma. Showing expression of desmin in rhabdomyoblasts

to show histological similarity to tumours such as chondroblastic osteosarcoma and malignant fbrous histiocytoma. Additionally, low-grade tumours may show benign histology such as chondromatosis or osteochondroma.

Surgery remains the primary treatment modality, possibly driven by the belief that these tumours are radio-resistant. Additionally, irradiating areas such as the skull base can be carried out with conventional external beam photon therapy particularly with new techniques like Intensity modulation radiation therapy (IMRT). The role of proton beam therapy delivering high-energy irradiation has shown local control rates of 85–100% at 5 years [42].

The site of the primary tumour has implications for prognosis; for example, laryngeal primaries do better compared to nasopharyngeal primaries. High-grade and dedifferentiation confers poor prognosis due to early local recurrence and distant metastases. The 5-year overall survival rates are less than 50% vs. 80% or greater for high- and low-grade tumours, respectively.

#### **83.14 Angiosarcoma**

These tumours arise from the endothelial cells lining the vascular or the lymphatic system. They are most common above the age of 62 years and show male predilection with a ratio of 2:1. They can arise in several different sites given the wide distribution of the endothelium. Some lesions are localised and nodular, whilst others are diffused. Regional metastases are less than 20% of patients at presentation. However, distant metastases may be present in up to 45% of patients at presentation, mostly involving the lungs and liver [6–8]. The tumours show immune positivity for CD31. Histological examination shows anastomosing and infltrating channels

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 83.10** Angiosarcoma. H&E section showing pleomorphic tumour cell lining interconnecting atypical vascular channels

lined by multilayered endothelial cells with variable atypia (Fig. 83.10). Free-foating endothelial cells of 'fsh in the creek' pattern with surrounding adnexae and dermal collagen can be a reliable feature [42].

Although surgery is the primary modality of treatment, diffuse lesions can make adequate surgical clearance a diffcult task. The reported 5-year survival rates range from 12 to 40%. Predictors of poor survival include location of the primary tumour, size greater than 7 cm at presentation, highgrade and advancing age [1, 20, 23]. Local recurrence is seen in more than 50% of patients with inadequate or positive surgical margins, usually within 2 years. The role of adjuvant therapies is questionable in achieving adequate loco-regional control and improving survival.

#### **83.15 Malignant Schwannoma**

These are tumours arising in the nerve: peripheral or cranial. They usually affect the neck, followed by sinonasal areas. Involvement of the maxillofacial skeleton is rare. Although there is an association with von Recklinghausen's disease or neurofbromatosis type 1, sporadic tumours are well recognised [43]. Surgery remains the primary treatment modality. Tracking of the tumour along the nerve sheath limits the resectability, hence the need of adjuvant therapies, be it radiotherapy or chemotherapy.

#### **83.16 Fibrosarcoma**

These tumours often present as an asymptomatic painless mass between 30 and 40 years of age. History is positive for previous radiation exposure in at least 10% of patients. Histological similarities are seen with malignant fbrous histiocytoma [6, 7, 44]. Surgery remains the mainstay of treatment, with adjuvant radiotherapy aimed at those with inadequate surgical margin and lessons that are high-grade. The reported 5-year survival rates are 80% or greater [22, 23].

#### **83.17 Kaposi's Sarcoma**

Human herpes virus 8 is implicated in the aetiology of these tumours arising in patients with AIDS. It is worth noting that Kaposi's sarcomas represent up to 80% of oral cavity sarcomas and have poor prognosis [25, 45].

#### **83.18 Synovial Sarcoma**

Contrary to the name, synovial sarcomas arise from the pluripotent mesenchymal cells, not the synovial cells. They show a male predilection and a peak incidence between 20 and 40 years. The common head and neck subsites are the hypopharyngeal and retropharyngeal areas. It is worth noting that up to 50% of patients have pulmonary metastases at presentation [5, 7, 15].

All histological subtypes (monophasic, biphasic, poorly differentiated) are high-risk tumours. Up to 90% of patients have chromosomal translocation (tX: 18) [21]. Prognosis tends to be poor with less than 20% of patients with metastasis at presentation alive at 2 years. Increasing age, size greater than 5 cm and poor differentiation predict worst prognosis [18, 22].

#### **83.19 Ewing Sarcoma**

These tumours arise in privative neuroectodermal cells and represent 5% of primary tumours. They are second most common malignant tumours of the bone in children. Subtypes include osseous and extraosseous. Metastases at presentation are seen in 20% of patients, mostly involving the lungs [46]. History may be positive of prior childhood malignancies treated with irradiation or chemotherapy. Most patients present with an enlarging mass that may be asymptomatic or painful. Destructive lesions due to osteolysis are evident on radiographs.

### **83.20 Conclusion**

Sarcomas are aggressive tumours, fortunately rare in the head and neck regions except for rhabdomyosarcoma in children, which has shown good, improved outcomes with current treatment regimens. The primary treatment modality is surgery, often preceded by neoadjuvant chemotherapy and followed by postoperative chemoradiotherapy. Large tumours with a risk of positive surgical margins and histologically high-grade tumours are adverse features. Age is an independent prognostic factor in children and adults with sarcomas arising in Paget's disease for bone.

Treatment regiments are often institution-dependent and biased. Given the lack of randomised controlled trials and diffculty in interpreting meta-analysis, close cooperation and data sharing between centres can go a long way in improving treatment outcomes for this diverse group of patients.

#### **References**


toneal sarcomas: a 15-year single-institution evaluation of prognostic features. J Surg Oncol. 2016 Jul;114(1):56–64.


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

Amit Dhawan

#### **84.1 Introduction**

Oral cancer is the sixth most common cancer in the world, primarily caused by consuming tobacco and its products, alcoholism, nutritional defciencies, poor oral hygiene, certain strains of human papillomavirus (HPV) and genetic predilection [1, 2]. Considering global incidence of oral cancer, more than 50% of overall head and neck cancer are occurring in Asian subcontinent with India having maximum numbers of these patients. According to some epidemiological studies in Asian Indian population, approximately 80,000 to 1,20,000 new patients of oral cancers are being diagnosed yearly, making oral cancer the third most common cancer in India after lung cancer [1]. Oral cavity cancers are primarily treated surgically owing to gross visual disease, easy accessibility, and less chance of obtaining the R1 resection (resection with positive margins). Retrospectively, all T1 and some of T2 lesions of oral cavity were treated with primary radiotherapy with curative intent, but the results were more promising with upfront surgery followed by some kind of adjuvant treatment depending upon the fnal histopathology report. Developing countries like India have nonstandardized oral cancer screening protocols due to which most of the oral cancer patients are missed at an early stage and are presented at an advanced stage (stage III–stage IV) with higher T stage (T3–T4) and dissemination of disease in the lymphatics of the neck which further reduces the prognosis for the survivability of the patients. There are other independent predictors on which prognosis of an oral cancer patient depends on like depth of invasion of tumor, involvement of lymph nodes in the neck (lymph node ratio), pattern of invasion of tumor, extranodal extension, and presence of positive margins after surgery. In the recent past, advanced-stage (stage III–stage IV) oral cancer was primarily managed by upfront ablative resection and neck dissection followed by postoperative

©Association of Oral and Maxillofacial Surgeons of India

adjunctive radiotherapy depending upon the other predictors of prognosis. This dual modality approach of followed by radiotherapy has given promising results in advanced-stage cancers, but the overall survival beneft came out to be as low as 40% [2–5].

In 2004, two large-scale trials were conducted, Radiation Therapy Oncology Group (RTOG) 9501 in America and European organization for Research and Treatment of Cancer (EORTC) 22,931. The results of these trials had provided the new insights for the management of advanced head and neck squamous cell carcinoma. The evidence from these landmark trials confrms the use of chemotherapy to the adjuvant radiation regime in the treatment of advanced-stage squamous cell carcinoma patients [5, 6].

The addition of chemotherapy may result in better locoregional control, overall survival, and metastasis-free survival in these patients. The three major pillars of treatment for oral squamous cell carcinoma are surgery, radiotherapy, and chemotherapy. To get the maximum survival advantage from these treatment modalities, all the three treatment modalities have to be used as an adjunct to each other [2, 3] (Fig. 84.1).

A. Dhawan (\*)

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_84

**84**

**Adjunctive Therapy in Oral Cancer**

Department of Oral and Maxillofacial Surgery, SGRD Dental Institute, Amritsar, India

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1903

#### **84.2 Basic Principles of Radiotherapy**

When the radiation is used for the purpose of treatment, especially in the patients of oral cancer, it is referred to as radiation therapy or radiotherapy. Radiotherapy is frequently used in as an adjunctive therapy or adjuvant therapy, to improve both local-regional control and overall survival. Radiation therapy is thought to kill tumor cells via damage to their DNA. The amount of radiation is typically measured in the unit gray (Gy), which represents joules of energy per kilogram. The following gives the conversion between grays, radiation absorbed dose (rad), and centigrays: 1 Gy = 100 rad = 100 cGy [7, 8].

External beam radiotherapy refers to the treatment, when a targeted beam of energy in the form of radiation is directed from a machine placed outside the patient to an area to be irradiated located within the patient. However, a radioactive substance may be introduced directly within an existing tumor or tumor-bearing area which is referred to as brachytherapy. Arranging for a patient's radiation treatment involves a number of steps before treatment can commence, of which the frst is a dental evaluation and appropriate dental care. After consultation, a patient is simulated, which usually involves obtaining a computed tomographic (CT) scan, while the patient is immobilized with a face mask. Afterward, the radiation oncologist outlines the disease on the scan (contouring). Then a medical physicist and dosimetrist devise a method to deliver the radiation safely to the patient while avoiding radiation to normal anatomical structures. At the time of treatment, the radiation therapists verify that the patient lines up appropriately before treatment can begin. Immobilization of the patient is carried out with a predesigned face mask made up of a thermoplastic material. It is to be noted that accurate positioning of the patient without movement and the ability to recreate the same position of the patient every time (up to 6 weeks) are important factors for overall effective radiation treatment of the patient [7–10].

#### **84.2.1 Biology of Radiation Therapy**

The current understanding of radiotherapy techniques makes use of radiobiological principles for better treatment planning and outcomes. These principles infuence the response of both normal tissues and of tumor clonogens to ionizing radiation, and a basic understanding and application of these principles are vital to improve the narrow therapeutic ratio of tumor versus normal tissue damage.

The 5R' concept of radiobiology is as follows [9, 10]:


#### **84.2.2 Primary Radiotherapy**

This is also called as radical radiotherapy. The indications of primary radiotherapy only include early-stage oral cancers like carcinoma of lip, ventral surface of tongue, and foor of mouth. According to some reports, primary radiotherapy is indicated for treating T1 and T2 cancers with proliferative character. It is believed that the local control and overall survival of the patients are similar in these cases without upfront surgery with an added advantage of preservation of cosmetic, anatomic, and functional integrity of the head and neck region. The literature supports the use of postoperative radiotherapy instead of preoperative radiotherapy even for smallsized tumors as the locoregional recurrence is reported to be slightly more in primary radiotherapy group as compared to postoperative radiotherapy group, but the survival advantage is not statistically signifcant.

After radiation therapy, the preferred method for assessment of tumor response, in addition to clinical and endoscopic examination, is a posttreatment positron-emission tomographic (PET)/CT scan at 12 weeks. In most patients with a complete response to therapy and negative PET scan results, routine neck dissection is not recommended in the postoperative setting.

#### **84.2.3 Indications of Adjuvant Radiotherapy**

The treatment for the stage III and stage IV oral cancer is complex. According to current National Comprehensive Cancer Network (NCCN) guidelines, single-modality treatment with either surgery or radiotherapy is recommended for approximately 30% to 40% of initial stage oral carcinoma patients (stage I and II). Both modalities of treatment have resulted in comparable survival beneft in these patients. On the other hand, combined modality treatment is generally recommended for the approximately 60% of patients with locally or regionally advanced disease at diagnosis. The treatment in these individuals depends on factors such as site of the disease, stage, pathological fndings, and presence of adverse features in the resected specimen. Several studies have classifed the oral cancer patients into low risk, medium risk, and high risk [2, 3].

Postsurgical adjuvant radiotherapy is indicated according to the presence of adverse features on fnal histopathology.

The adverse features refer to extranodal extension, lymphovascular invasion, and perineural invasion.

Patients who are classifed as high or intermediate risk of relapse beneft the most from the addition of postoperative radiotherapy.

The indications of adjuvant radiotherapy after primary ablative surgery in oral cancer patients are as follows:


Often, radiation to the head and neck involves the selection of different doses depending on the amount of disease in that area. Typically, gross disease receives a dose of 70 Gy. Areas at high risk of microscopic disease often receive a dose of between 60 and 66 Gy. Areas at low risk of microscopic disease typically receive a dose of 50–54 Gy. The areas designated at high risk and low risk will depend on the site of occurrence of disease, the stage, and presence of pathological adverse features. The most common fraction size is 2 Gy of radiation per day [10–13].

#### **84.2.4 Efect of Radiation Treatment Delay**

Postsurgical radiation delay has a profound effect on overall survival of patient. Tumati V et al. found an association between treatment delays and oncologic outcomes in patients treated with surgery followed by post-op radiotherapy in a total of 277 patients of oral and oropharyngeal carcinoma. On multivariate analysis it was observed that radiation treatment time had a signifcant impact on locoregional recurrence in these patients. The authors found out that delays in the postoperative radiation therapy >43 days were associated with statistically signifcant locoregional recurrences (*p* = 0.02) in patients with non-p16-positive cancers. Many investigators have studies in coherence with the above conclusions. An increase in distant metastasis appears to be the mechanism by which prolonged time to treatment initiation leads to worse overall survival [14].

#### **84.3 Radiotherapy Techniques**

Depending upon the indication and treatment plan, there are multiple techniques with which radiation therapy can be delivered to a patient undergoing treatment for oral cancer. The techniques of radiotherapy should deliver the calculated radiation dose to the patient as per treatment plan without much toxic effects to the normal tissues. Some of the radiation techniques are listed below (Table 84.1) [15–19].


#### **Table 84.1** Radiation techniques

#### **84.3.1 Radiation Dosage and Fractionation Schedule**

Radiotherapy schedule, conventionally, is followed for 5–7 days a week with defned breaks in the treatment for reoxygenation and repair of normal tissue cells of the body for target effectiveness of radiotherapy. According to the literature, the tumor cells repopulate in between the radiotherapy regime especially after fourth week, so unscheduled breaks between the course of radiotherapy are not recommended by the radiation oncologists. That's the reason different fractionation schedules have been advocated by the radiation oncologists for successful completion of the treatment without unnecessary treatment breaks which can have a negative impact on the fnal outcome of the patients [15–19].


#### **84.4 Complications of Radiotherapy**

Though the dual-modality treatment (surgery and radiotherapy) has become a norm for the treatment of advanced-stage (stage III–stage IV) oral squamous cell carcinoma, there are some unavoidable toxic effects of radiation therapy which can affect the quality of life (QOL) of the patient. Radiotherapy has proved to be very effective in improving the locoregional control and overall survival of the patient, but there are short-term and long-term sequel of radiotherapy which sometimes limit the effectiveness of the therapy due to breaks in the treatment schedule. The intensity of the complications and toxic effects depends upon the dose of delivered radiation and the site exposed to the radiation therapy. Radiation techniques like intensity-modulated radiotherapy IMRT and image-guided radiotherapy IGRT are helpful in controlling the delivered dosage of radiation to the patient, thereby decreasing the rate of complications and increasing the response of the patient toward the therapy.

Depending upon the response to radiation, the complications have been divided into acute toxic effects or short-term sequel and chronic toxic effects or long-term sequel.

IMRT requires that the radiation oncologist outline the tumor, the areas at risk for microscopic spreading, and the critical normal structures on every CT slice (contouring). Outlining the gross disease (gross tumor volume [GTV]) and areas at risk of microscopic spreading (clinical target volume [CTV]) requires a thorough understanding of the anatomy of the region and is signifcantly more labor-intensive than prior two-dimensional or conventional radiation therapy techniques.

#### **84.5 Acute Toxic Efects**

#### **84.5.1 Xerostomia**

Xerostomia is also referred to as dry mouth. It is one of the most common acute and chronic side effects of radiotherapy. Xerostomia starts from the frst week of radiotherapy and is a more common complaint in the frst 2 weeks in those patients in whom submandibular salivary glands have been removed as part of the neck dissection. As far as possible, contralateral submandibular salivary gland should be preserved in uninvolved neck when bilateral neck dissection has to be performed. With the traditional radiographic techniques, parotid gland was not spared which resulted in more profound effects of dry mouth leading to halitosis, stasis of thick saliva, dysphagia, and cervical caries. Stasis of thick saliva leads to dysphagia like symptoms and even aggravation of mucositis earlier in the course of therapy.

Intensity-modulated radiotherapy technique and imageguided radiotherapy have revolutionized the concept of delivery of radiotherapy, thereby minimizing the risks of development of unavoidable side effects like xerostomia leading to more acceptable quality of life. A randomized controlled trial by Nutting et al. confrmed the reduction in postradiation xerostomia signifcantly. They compared intensity-modulated radiotherapy without taking parotid gland in the radiation feld and conventional radiation therapy for all patients. About 83% patients developed grade II or higher xerostomia with conventional radiotherapy as compared to 29% of patients who were adopted for parotid sparing intensity-modulated radiotherapy [19].

Many investigators have assessed the relationship of radiation dosage to parotid and submandibular gland and severity of xerostomia at weekly intervals. The inference from these studies point toward the damage to plasma membrane of secretory granules of glands. Another observation was that the fow of saliva from submandibular and parotid glands considerably decreases up to less than 20% of pretreatment values by the end of the second week of radiation therapy. The recommendations are to use current radiotherapy techniques like intensity-modulated radiation therapy to spare the submandibular and parotid gland with lowest possible exposure. The treatment of xerostomia converges toward the usage of sialagogues, artifcial saliva, and fuid therapy along with reassurance to the patient [20, 21].

#### **84.5.2 Oral Mucositis**

Oral mucositis due to radiotherapy and other systemic therapies in oral cancer treatment represents a major complication causing a wide spectrum of clinical signs and symptoms. Oral mucositis may hamper the quality of life, resulting from debilitating oral pain and bleeding from oral cavity, dysphagia, infections, and inability to chew food and may interfere with the ongoing radiation treatment, ultimately jeopardizing overall patient outcome. According to certain reports, third week of post-radiotherapy is the most crucial time when the mucositis begins to set in and the severity increases in the subsequent weeks. The severity and agony from mucositis is directly proportional to the total dosage of radiation delivered and the volume of irradiated tissue in a specifed interval of time. Mild initial erythema to patchy mucositis (characterized by white patches of fbrinous exudate on an erythematous base) to confuent mucositis (where the exudative patches coalesce) are the presenting symptoms of progression of ongoing mucositis in the oral cavity. On the other hand, if there is an evidence of bleeding to touch from the oral ulcers, it is considered as severe to fulminant mucositis.

Confuent mucositis, common toxicity criteria (CTC) grade 3, is seen in 40–80% of patients receiving more than 60Gy (or equivalent), more frequently in those receiving concurrent chemotherapy or accelerated radiotherapy. The patients should be advised to keep good oral hygiene with 0.12% chlorhexidine gluconate along with sialagogues or artifcial saliva which will have protective action for the underlying oral mucosa thus reducing the severity of symptoms and relieve the pain. A narcotic analgesic like tramadol is recommended for pain from mucositis. There are some reports which favor elemental zinc or zinc carnosine complex for relieving the symptoms of severe mucositis.

The role of nonalcohol-based mouthwash has been established by many authors for relieving the debilitating effects of mucositis. Topical steroids had been used in past for the treatment of mucositis in severe stages, but their use is constantly discouraged in the current settings. The radioprotectant drug amifostine has been investigated as a means of reducing the incidence of xerostomia and mucositis. The route of administration of amifostine is intravenous everyday prior to initiation of radiotherapy. Patient should be constantly monitored for hypotension and nausea postoperatively.

Moreover, WHO recommends the constant nutrition support to the patients undergoing radiotherapy which will have a positive effect on the recovery from acute mucositis. If oral route is jeopardized, the nasogastric feeding, PEG percutaneous endoscopic gastrostomy, and parenteral nutrition should be considered based on the severity of mucositis. Recovery of severe mucositis may not begin until 2–3 weeks after treatment completion then take up to 4–8 weeks to regain normal swallowing. The recovery is mostly complete; however, only <5% of patients may remain PEG dependent.

*Other known acute toxic effects of radiotherapy* are erythema of facial and skin of the neck, lethargy, loss of taste, and smell. Erythema of the skin takes about 7–10 days of complete remission after cessation of radiation therapy; however the skin remains photosensitive even after the completion of therapy [20–22].

#### **84.6 Chronic Toxic Efects**

There are multiple chronic toxic effects of radiotherapy enumerated in the literature by different authors and radiation oncologists (Table 84.2). It has been found out that the chronic effects of radiotherapy are more dependent on dosage than the acute effects of radiation.

#### **84.6.1 Osteoradionecrosis of Maxilla and Mandible**

Currently, one of the most serious long-term or chronic complications of radiotherapy to the head and neck region is osteoradionecrosis of the jaws. The associated morbidity of this complication and its subsequent treatment will include close observation and/or radical surgical resection followed by reconstruction with free fbula, deep circumfex iliac artery fap (DCIA), or a variety of pedicled and soft tissue free faps depending upon the severity of necrosis and systemic condition of the patient.

The etiopathogenesis of osteoradionecrosis have been explained on the basis of current theory of Delanian and Lefaix [23]. It states that osteoradionecrosis of the jaws is a radiation-induced fbrosis with histopathological formation of phases which appear similar to those of chronic wounds. There is a histopathological picture of combination of dead or dying osteoblasts without replication of new osteoblasts and excessive proliferation of myofbroblasts. This condition is manifested as loss of trabeculae of existing bone and subsequent decrease in the quality and structure of underlying bone.

Among the risk factors for the development of osteoradionecrosis, total radiation dose delivered to the bone, in a specifed period of time, remains the most important and crucial risk factor. The cumulative dose of radiation to the bone will **Table 84.2** Chronic effects of radiotherapy


produce an environment of hypo-cellularity and hypovascularity leading to the cause and effect relationship in the underlying bone. Maxillary bone is less susceptible to the development of necrosis than mandible as maxilla has a more porous structure of bone with more vascularity as compared to a single terminal inferior alveolar artery in mandible which undergoes fbrosis after high-dose radiation therapy. Moreover, muscles of facial expression and thick mucoperiosteum in maxilla prevent it from getting hypo-vascular in a shorter period of radiation therapy. Facial artery is notoriously unreliable to produce collateral blood supply to the mandible which is insuffcient to prevent osteoradionecrosis. On the other hand, in case of post-neck dissection patients, the facial artery is most of the time ligated in the ipsilateral side during the clearance of level IB (submandibular) group of lymph nodes.

According to a comparative study conducted by Kuhnt et al. [22] on 776 patients with head and neck cancer who underwent intensity-modulated radiotherapy as radical radiotherapy for the treatment of head and neck cancer and as postoperative radiotherapy, the highest cumulative incidence of osteoradionecrosis was found to be 12.4%, and relative frequency was 6.6%. The interesting inference of this study is the actual risk for the development of osteoradionecrosis remains there for a lifetime of the patient and may increase by a factor of two in long-term survivors. There remains a highest risk for the development of osteoradionecrosis in patients who had undergone primary bone surgery during tumor resection (hazard ratio: 5.87 95% confdence interval) and in patients with tumor located in the oral cavity than other sub-sites in the head and neck region. This means the dental treatment including extractions and minor surgical procedures should be performed well before in the patients advised for adjuvant radiotherapy in which mandibular resection (marginal mandibulectomy or segmental mandibulectomy) has been advised. Moreover, it is prudent to cover the marginal mandibulectomy defect with the free fap or a soft tissue pedicled fap to maintain vascularity so as to prevent postradiation chance of osteoradionecrosis.

Gender, dentition (dentulous vs edentulous), and concurrent chemotherapy have no signifcant clinically relevant infuence on the development of osteoradionecrosis. Males are found to have three times more risk for the development of osteoradionecrosis than women. According to a study conducted by Gabriela et al., 25% of patients developed refractory osteoradionecrosis which required some kind of resection and subsequent reconstruction when the radiation dose delivered were more than 66Gy at a daily fraction exceeding up to 2.2Gy as compared to no evidence of osteoradionecrosis at or below 65 Gy of radiation dose [24]. On the other hand, as the daily dose of radiation decreases to 1.8 and 1.9 Gy, and a total dose of 69–75.6 Gy, the rate was 19.6%. Daily dose of radiation is thus considered to be a most signifcant factor in determining likelihood of developing osteoradionecrosis especially in cases of oral cancer. The close proximity of the cancer to the mandible (with in 1 mm) receiving high dose of radiation remains the other risk factors for the development of osteoradionecrosis.

Prevention is better than the treatment of osteoradionecrosis. One study confrms the effectiveness of hyperbaric oxygen therapy in a very few number of patients. State-ofthe-art radiotherapy techniques will limit the total absorbed dose to the mandible and potential sites in the oral cavity thus limiting the incidence of osteoradionecrosis [24, 25].

#### **84.7 Principles of Chemotherapy**

The oral cancer is considered as the sixth most common malignancy worldwide accounting up to 1,30,000 cases every year in a developing country like India. Due to poor screening facilities at primary examination level, lack of awareness among patients, and nonstandardization of public health sector, most of the cases are diagnosed when they have attained stage III and stage IV disease.

On the other hand, chemotherapy regimens for oral cancer treatment are evolving. There are multiple methods by which chemotherapy may be offered to the patients for the management of head and neck cancer to improve the overall outcomes in terms of survivability of patients.

*Methods of providing chemotherapy for head and neck cancer patients are as follows:*


Single-modality treatments usually have low effcacy in terms of locoregional recurrences. On the other hand, chemotherapy with or without radiotherapy poses the patient toward the risk of systemic toxicities and unwanted immunosuppression which may alter the overall result and outcomes of the patient undergoing cytotoxic therapy in any form [25–29].

#### **84.7.1 Cytotoxic Chemotherapeutic Agents**

While multiple cytotoxic drugs have been identifed for the treatment of oral squamous cell carcinoma in addition to surgery and radiotherapy, some of the chemotherapy agents are listed below (Table 84.3).

#### **84.7.2 Chemoradiation in Oral Cavity Cancers**

Earlier it was thought that radiation therapy alone is effective for treating small T1 and T2 lesions of lower lip, foor of mouth, tongue, and palate within the oral cavity. After a decade, many centers adopted surgery alone for smaller lesions of oral cavity as primary treatment. Then a dual-modality approach (surgery followed by radiotherapy) was popularized for locally advanced carcinoma (stage III–stage IV AJCC eighth edition) of oral cavity. Hence, the dual-modality approach emerged as a conventional, widely accepted, and equally effective treatment option for the management of advanced (T3–T4) lesions. Conventionally, the combination of chemotherapy and radiotherapy, as primary treatment modality, had been reserved for those patients with unresectable disease or patients who refuse the surgical treatment.

It has been published by the RTOG trial reports that adjuvant radiotherapy improves the outcome of patients which received the surgical treatment for advanced-stage squamous cell carcinoma arising in the head and neck. At the same time, the disease-free survival and 5-year overall survival came out to be generally between 30 and 40% which is highly nonpromising. These trials also suggested that if the concurrent chemotherapy, using cytotoxic drugs, is added to the conventional postoperative radiotherapy regime, the effects of radiotherapy are intensifed. This methodology of adjunctive treatment has signifcant amount of survival beneft than dual-modality treatment, and the chances of locore-


**Table 84.3** Chemotherapy agents used in oral cancer

gional recurrences are likely to be less especially in high-risk patients postoperatively. In the last 10 years of research in the feld of head and neck carcinoma treatment, the effcacy of triple-modality therapy has been justifed in the literature for postoperative high-risk squamous cell carcinoma patients. Like RTOG a similar trial was conducted in Europe, the EORTC trial. This trial also reconfrmed the addition of adjuvant chemotherapy to the radiotherapy regime. The inference of this trial showed better rates of local control, diseasespecifc survival, and overall survival and signifcant decreased incidence of late toxic effects. Both these trials compared the addition of three planned cycles of concomitant cisplatin at 100 mg/m2 every 3 weeks to radiotherapy (60–66 Gy, over 6–6.5 weeks, standard fractionation) with the same radiotherapy alone in patients with adverse feature of head and neck carcinoma. Therefore the concomitant therapy with cisplatin at 100 mg/m2 every 3 weeks with adjuvant radiotherapy on day 1, day 22, and day 43 is the regimen of choice. The only limitations of these two trials were that these trials were not oral cancer specifc. There are very few studies in the literature who have evaluated the concept of triple-modality therapy yet being site specifc to oral cavity. Choi et al. retrospectively reviewed 861 patients with oral carcinoma treated in Korea from 1984 to 1996. Almost 63% of patients had stage III and stage IV cancer, and 36% had T3–T4 lesions. The authors concluded that triple-modality treatment (upfront surgery followed by postoperative chemoradiation) yielded a greater treatment response rate than dual-modality treatment [29]. On the other hand, Zhang et al. conducted a trial in oral cancer patients who received surgery followed by radiotherapy as a primary treatment modality. The trial found out that there is a 3.6 times more incidence to develop distant metastasis in surgery and radiation group as compared to surgery followed by chemoradiation group [3].

### **Box 84.1 Questions to be answered**

Now the question arises.


*Explanation for Q1&2*: Results of the recent study conducted by Stenson et al. revealed that patients who underwent chemoradiation as primary therapy for advanced-stage oral squamous cell carcinoma had a greater rate of metastasisfree and overall survival beneft with 66.9% disease-free or progression-free survival [30]. One of the recent singleinstitutional study conducted by Dhawan et al. on 128 patients of advanced-stage high-risk oral carcinoma shows an overall survival beneft of 10% in patients receiving chemoradiation as compared to patients receiving only radiation therapy after primary ablative surgery. This study was conducted in a subset of Asian Indian population to evaluate the benefts of multimodal therapy in the management of stage III/IV oral carcinoma [2]. Zhang et al. in their study showed a survival beneft of 11% in patients receiving chemoradiation as compared to radiation alone [3].

*Explanation for Q-3*: But the survival beneft doesn't come without a price to the patient. Along with improved survival comes the greater incidence of acute and chronic toxicities due to cytotoxic chemotherapeutic agents. The chances of recurrence always remain high even with the addition of chemotherapy due to the advanced stage and higher volume of the disease being treated. The recurrence potential of the lesion depends on the invasive pattern of tumor invasion at the frst place and the presence of cancer stem cells in a given area. According to Pericot et al., high incidence of recurrence is associated with size of the primary tumor (T stage), and the diffculty in obtaining margins free of disease, after surgical resection. So obtaining a positive margin or a close margin (between 1 to less than 5 mm) after resection becomes an indication for administration of concurrent chemoradiation therapy. On the other hand, the development of myelosuppression, neutropenia, mucositis, and xerostomia is inevitable with triple-modality treatment [31].

*Explanation for Q-4*: The type of radiation (IMRT and routine radiotherapy) also affects the survival outcomes when used concurrently with chemotherapy as IMRT is more effective along with chemotherapy than with conventional radiotherapy.

*Explanation for Q-5*: Neck node involvement is also considered as an independent predictor of survival in oral cavity cancer. According to the literature, patients with nonpalpable disease in the neck or clinically N0 necks are having greater overall survival rate as compared to subsequent N stages. A recent study by Franceschi et al. found that among patients with involved neck nodes, survival rate was signifcantly lower when more than two levels of lymph nodes were involved, or when extranodal extension was observed. The adverse features which are found after fnal histopathological examination of primary as well as neck dissection specimen are currently addressed as extranodal extension, perineural invasion, and lymphovascular invasion. These patients are particularly at higher risk of disease progression and have higher death rates [32]. According to Zhang et al. [3], patients with extranodal extension and perineural invasion had improved disease-specifc and metastasis-free survival in the surgery followed by chemoradiation group (*p* < 0.05). In a retrospective study conducted in 2016, authors found out that overall survival was signifcantly infuenced by the type of modality and regional spread of disease. Chemoradiation after primary ablative surgery group had improved overall, disease-specifc, disease-free, and metastasis-free survival compared to surgery followed by radiotherapy group even in patients with extranodal extensions, perineural spread, and lymphovascular invasion.

According to RTOG and EORTC landmark trials, there are some absolute indications for postoperative chemoradiation. These studies provided the base for the risk-adapted strategies in postoperative adjuvant therapy and *established extranodal extension and positive surgical margin as the absolute indications for adding concomitant systemic chemotherapy to adjuvant radiation*. However, proper patient assessment preoperatively is mandatory keeping in view the systemic toxicity due to chemoradiation.

#### **Absolute Indications of Adjuvant Chemotherapy in Oral Cavity Cancers**

According to RTOG trial, the defnition of high-risk patients is as follows:


#### **84.7.3 Induction Chemotherapy Before Surgery**

Since 1982, during the days of early clinical trials on chemotherapeutic agents and their clinical advantage in head and neck squamous cell carcinoma, induction chemotherapy was thought to have potential benefts for treating head and neck cancers. Unfortunately, the higher response rates of these chemotherapeutic results have failed to result in statistically signifcant survival beneft. Induction chemotherapy before surgery is generally instituted in primarily unresectable oral cavity cancers at some centers. The effcacy of induction chemotherapy has yet to be proven in oral cancer treatment with regard to locoregional control and/or overall survival of these patients. The effcacy of induction chemotherapy to downstage oral cavity cancers was observed by a study conducted by Grau et al. in a prospective way with unresectable stage III–stage IV oral cavity cancers. They found out that disease-free survival at 5 years was 26% for patients undergoing resection and 22% for patients who received chemoradiation. Improved outcome is always at an expense of increased toxicity. There are other studies with comparable results which were carried out exclusively in oral cancer patients. Currently, induction chemotherapy cannot be recommended in resectable oral cancer patients for improvement in the survival [33].

#### **84.7.4 Palliative Chemotherapy in Patients with Oral Cancer**

Patients with recurrent and metastatic squamous cell carcinoma of head and neck are considered incurable with surgery or radiation. In these patients mainstay of treatment remains the systemic chemotherapy with cytotoxic chemotherapeutic drugs. Chemotherapeutic agents can be used either in combination regimen or as single agent in the management of metastatic oral cavity carcinomas. Radiation therapy with concurrent cetuximab, a monoclonal antibody to epidermal growth factor receptor (EGFR), has been shown to signifcantly improve overall survival rates compared with radiation therapy alone in the palliative setting. A direct randomized comparison of cetuximab versus platinum-based regimens is underway at many centers in the world. At present, platinum-based regimens (cisplatin, carboplatin) are preferred over other drugs, as long as patients can tolerate the regimen with acceptable complications [34–36].

#### **84.8 Conclusions**

Adjunctive therapies are included in the treatment regimen of oral squamous cell carcinoma to improve the disease-free, metastasis-free, and overall survival of the patients. Adjuvant radiotherapy is indicated in high-risk advanced-stage (stage III–stage IV) oral squamous cell carcinoma patients as dual modality. The complications and side effects of radiotherapy can be reduced by adopting advanced radiotherapy techniques like intensity-modulated radiotherapy, image-guided radiotherapy, and stereotactic radiotherapy. Concurrent chemoradiation therapy is adopted as primary treatment in patients with locally advanced oral cavity cancer whose disease is not amenable for surgical resection. Adjuvant chemoradiation is indicated in patients having postresection positive margins and with extranodal extensions or extracapsular invasion as a multimodality treatment. Consider cetuximab synchronously with radiotherapy in patients unsuitable for platinum-based chemoradiation.

#### **References**


and radiotherapy for head and neck cancer. Head Neck. 2019 Feb;41(2):315–321.


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## **Access Surgeries and Osteotomies for the Maxillofacial Region**

Madan G. Ethunandan

#### **85.1 Bicoronal Scalp Flap**

The bicoronal fap was frst described by Hartley and Kenyon [1] to access the cranium and popularised by Tessier [2] to provide additional access to the orbits and midface. Various modifcations of the fap have been described and include a zigzag (stealth) incision [3], deeper plane of dissection in the temporal scalp region to avoid damage to the facial nerve [4, 5] and strategies to minimise alopecia [6].

The coronal fap provides access to the skull, anterior and middle cranial fossa, upper midface including the nasoethmoid region and orbits and temporal and infratemporal fossa.

The SCALP is an acronym consists of fve layers: *S*kin, sub*C*utaneous connective tissue, galea *A*poneurotica, *L*oose areolar tissue and *P*ericranium. The frst three layers are frmly attached to each other and are raised as a single layer, superfcial to the loose areolar tissue (avascular plane of Merkel). The blood vessels and nerves run within the frst three layers. The "perceived" complexity of the layers in the temporal region can be rationalised, if one was to consider the galea aponeurotica as a single layer which extends to the temporal region as the "temporoparietal fascia" (synonym superfcial temporal fascia/supra-zygomatic SMAS) and the pericranium extending as the "temporalis fascia" (synonym deep temporal fascia) overlying the temporalis muscle. The deep temporal fascia divides about 2–3 cm superior to the zygomatic arch into a superfcial and deep layers. The temporoparietal fascia, superfcial layer of the deep temporal fascia and the periosteum of the zygomatic arch fuse together on the lateral aspect of the zygomatic arch and contain the frontal branch of the facial nerve. The superfcial temporal fat pad is present between the superfcial and deep layer of the deep temporal fascia, with the deep layer attached to the deep

M. G. Ethunandan (\*)

Consultant Oral and Maxillofacial/Skull Base Surgeon,

Honorary Senior Clinical Lecturer, Lead, Head and Neck Cancer, University Hospital Southampton, Southampton, UK

aspect of the zygomatic arch. Dissection deep to the galea and the temporoparietal fascia affords a relatively bloodless plane and maintains and preserves the blood supply and avoids damage to the nerves, including the frontal branch of the facial nerve. This "safe" plane of dissection can be between the temporalis muscle and the "undivided" deep temporal fascia or (more inferiorly) between the superfcial and deep layers of the "divided" deep temporal fascia (Fig. 85.1a).

The frontal branch of the facial nerve crosses the zygomatic arch at least 8 mm (range 8–32 mm) in front of the external auditory meatus, at least 1 cm anterior to the superior attachment of the helix to the scalp, and runs no further than 2 cm above the frontozygomatic suture (Fig. 85.1b).

#### **85.1.1 Procedure**

The hair along the incision line can be parted or a small strip shaved. Local anaesthetic containing 1: 200,000 adrenaline is infltrated above the galea for appropriate haemostasis (you know you are in the right plane if increased resistance is felt. If it is easy to inject, you are in the deeper loose areolar tissue plane). The incision is marked from the anterior attachment of the helix and carried over the vault to the opposite side, inside the hairline (Fig. 85.1c). It can stop at the midline, if only unilateral access is required. If repeated access is likely to be required to the cranial skeleton, it would be useful to incorporate a posteriorly directed "curve", just above the helical attachment to the scalp, to try and avoid injury to the anterior branch of the superfcial temporal artery and maintain additional vascularity to the fap. A "bevelled" incision can be made parallel to the hair follicles to minimise alopecia, and a "zigzag" can be incorporated to reduce parting of the hair along a straight incision line. When designing the fap in male patients, the likely infuence of male pattern baldness should be taken into account.

The incision commences at the vertex between the superior temporal lines and is made with a blade through the

**85**

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_85

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 85.1** Scalp fap. (**a**) Layers of the scalp in the temporal region. Dotted line—dissection between the superfcial and deep layers of the (divided) deep temporal fascia. Solid line—dissection between the (undivided) deep temporal fascia and temporalis muscle. (**b**) Position of the frontal branch of the facial nerve. (**c**) Skin marking for a coronal fap. (**d**) Pericranial fap raised as an extension of the deep temporal fascia incision (note same plane of dissection). (**e**) Incision marked on the undivided deep temporal fascia. (**f**) Periosteal tunnel created along the zygomatic arch, deep to the position of the frontal branch of the facial nerve. (**g**) Exposure of the lateral orbit and zygomatic arch. (**h**) Temporalis muscle retracted to expose the temporal fossa and lateral orbital wall

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 85.1** (continued)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 85.1** (continued)

galea, up to the loose areolar tissue, and the superfcial three layers are raised as a unit. Blunt scissors or a brain retractor can be used to undermine the incision line along this plane, down to the root of the helix, and with the brain retractor in situ, the incision is made down to it. This allows rapid elevation of the fap, without inadvertent damage to the underling temporal fascia/temporalis muscle. Dissection is carried inferiorly in the subgaleal plane. The pericranium is incised approximately 3 cm above the superior orbital rim, and the dissection continued subperiosteally. Resistance can be encountered in the frontozygomatic and frontonasal suture region and around the supraorbital neurovascular bundles. If the supraorbital neurovascular bundle is present within a foramen, rather than a notch, the foramen can be opened with careful use of a fne osteotome (divergent cuts to minimise damage and ease of release).

A pericranial fap could be easily incorporated, by extending the pericranial incision superiorly to the required length, between the superior temporal lines, as an extension of the temporalis fascia incision (Fig. 85.1d). If a pericranial fap is to be utilised, the subgaleal dissection should stop 2 cm above the supraorbital rim, to maintain the vascularity of the pericranial fap.

Exposure of the nasal bones and frontal process of the maxilla can be facilitated by a vertical periosteal releasing incision in the midline. The medial canthal ligaments can be detached from the anterior lacrimal crest, which provides excellent exposure of the medial orbit up to the optic canal and the medial foor up to the infraorbital nerve.

The detached medial canthal tendon must be "tagged" through the periosteum with a unresorbable suture on a round-bodied needle, for subsequent reattachment to a microplate. Subperiosteal dissection medially is now possible as far as the foor of the orbit.

The skin incision is extended inferiorly in a naturally occurring skin crease, to just below the cartilaginous meatus, if exposure of the zygoma, lateral orbit or temporomandibular joint is considered. This could be modifed to follow the free edge of the tragus, to make this section less conspicuous. The dissection is carried forward medially following the cartilaginous meatus*.* At the superior attachment of the helix, the temporalis fascia is incised −1 cm above the zygomatic arch, and angled forwards to join the supraorbital periosteal incision 3 cm above the supraorbital rim (Fig. 85.1e). The incision is extended vertically in along the temporal fascia to the root of the zygomatic arch, which can be felt on palpation above the cartilaginous meatus. A pocket is created at the root of the zygomatic arch, deep to the periosteum and the soft tissues tented with a periosteal elevator to expose the arch. The soft tissues superior to the arch, on the surface of the temporalis muscle, can be transected down to the periosteal elevator to expose the zygomatic arch, zygoma and lateral orbit, without damaging the frontal branch (Fig. 85.1f, g).

Retraction of the temporalis muscle posteriorly provides additional exposure to the temporal fossa and the superior boundary of the infratemporal fossa (Fig. 85.1h).

Closure of the galea and meticulous haemostasis is essential, and drains and/or head dressing can be additionally utilised to prevent haematomas.

#### **85.1.2 Potential Complications and Solutions (Clinical Pearls)**

*Alopecia*: Use a knife for skin incision, meticulous haemostasis with judicious use of bipolar diathermy and tensionfree closure.

*Frontal nerve damage*: Appropriate plane of dissection, care during retraction and the use of diathermy in the temporal/ preauricular region.

*Supraorbital/supra-trochlear nerve damage*: Care during dissection in the supraorbital rim region and judicious use of fne/sharp osteotomes when deroofng the supraorbital foramen.

#### **Clinical Tips**


#### **85.2 Midface Access**

A modifed Weber-Fergusson approach remains the most popular transfacial approach to the midface. This access was originally described well over 150 years ago by Weber [7] from Germany and Fergusson [8] from the United Kingdom. Various modifcations have been incorporated over the years, and the more commonly used ones include the midline lip incision being placed on the philtrum [9], lateral eyelid extension [10] and medial eyebrow extension [11]. The original lateral rhinotomy incision was described by Moure [12], and a modifcation of the nasal component to lie along the nasal subunits was described by Thankappan [13].

A modifed Weber-Fergusson incision provides excellent access to the ipsilateral maxilla and, with appropriate extensions, provides additional exposure to the nasal cavity, orbit and ethmoid (Fig. 85.2a). The "nasal" part of the incision can be utilised for a lateral rhinotomy access.

A Le Fort I down-fracture osteotomy can also be utilised to access the nasal cavity, maxillary antrum, pterygopalatine fossa and clivus. However, with the widespread use of endonasal endoscopic techniques, its use has become limited. The technique is similar to that utilised in orthognathic surgery and is outlined in the orthognathic surgery chapter.

An intraoral vestibular incision can be joined with bilateral piriform fossa and intercartilaginous and septocolumellar transfxion incisions to "deglove" the upper lip, cheek and soft tissues of the nose to provide access to the maxilla and nasal cavity [14, 15].

A maxillary swing procedure can be utilised to access the posterior maxilla, pterygopalatine/infratemporal fossa and nasopharynx. However, with the widespread use of endoscopic techniques, its role has also become limited. Its principal use is in the management of recurrent nasopharyngeal tumours, which cannot be accessed endoscopically [16].

The modifed Weber-Fergusson commences with an upper lip split incision that is made along the philtrum and extended along the alar margins. A "V" can be incorporated along the nasal foor to improve localisation of the fap during closure. The incision is carried along the alar margin and extended superiorly at the junction between the nasal side wall and dorsal nasal subunit (Fig. 85.2a).

The intraoral incisions are made along the gingival crevice or buccal vestibule and are principally determined by the location of the tumour. A "V" can be incorporated in the lip mucosa to facilitate accurate approximation during wound closure. The cheek fap is elevated to expose the maxilla (Fig. 85.2b). The plane of dissection is principally determined by the extension of the tumour. A "tonsil" swab can be placed in the nasal cavity and soft tissues along the piriform rim transected to gain access to the nasal cavity and avoid inadvertent damage to the nasal septum.

Lateral extensions can be incorporated, if additional access is required to the orbits and zygoma. This is made along the subciliary/midtarsal skin crease and can be extended laterally along the crow's feet skin crease (Fig. 85.2a). Care is taken to elevate the skin fap "superf-

**Fig. 85.2** Midface access, (**a**) Marking for a modifed Weber-Fergusson incision respecting the nasal subunits. Lateral lower and upper eyelid extensions (for total maxillectomy with orbital exenteration) and medial glabella extension (for additional nasal access). Red

dotted lines with Lynch (superior) and crow's feet (lateral) extensions. (**b**) Exposure afforded by the incision. (**c**) Anterior ethmoid artery (arrow), exposed in the medial orbit along the frontoethmoid suture. (**d**) Lacrimal sac/nasolacrimal duct exposed in the lacrimal fossa

cial" to the orbicularis oculi muscle in the eyelid region to preserve function, and it is important to avoid "button holes" in the thin skin of the eyelids.

Superior extension (Lynch [11] modifcation) can be incorporated, if additional access is required to the medial orbit and ethmoids (Fig. 85.2a). The nasal sidewall incision is extended superiorly along the medial orbit at least, 5 mm medial to the medial canthus, up to the medial end of the eye brow/medial supraorbital rim. The incision deepened down to the bone and the frontal process of the maxilla, anterior lacrimal crest and frontonasal suture exposed. The medial canthal tendon is "formally" identifed and detached. It is "tagged" with a 3.0 Prolene suture on a round body needle, for subsequent reattachment. The medial orbit can now be exposed with fne periosteal elevators. The frontoethmoidal suture (FES) in the medial orbit provides an excellent landmark for the position of the anterior and posterior ethmoid vessels and optic canal. These vessels are identifed along the suture, skeletonised and ligated/diathermised (Fig. 85.2c). The optic canal lies posteriorly in superomedial orbit, in line with the suture. The number of ethmoidal vessels varies frequently [1–3] and the over-reliance of the distances between the vessels (24 mm, 12 mm, 6 mm) and the optic canal can be dangerous The FES can often lie "above" the cribriform plate, and its relationship to the anterior cranial fossa should be "critically assessed" in the preoperative scans. Osteotomies are best placed below the FES, if "unintentional" intracranial extension is to be avoided.

The lacrimal sac is identifed inferiorly in the lacrimal fossa and can be dissected free for retraction or transection (Fig. 85.2d).

A medial extension, along the glabella skin crease, can be incorporated if additional access is required to the nasal bones, roof of the nasal cavity, or if a "nasal" swing is considered (Fig. 85.2a).

The lower eyelid extension can be combined with a similar upper eyelid incision, if a lid-sparing orbital exenteration is planned (Fig. 85.2a).

#### **85.2.1 Potential Complications and Solutions (Clinical Pearls)**

*Unsightly scar*: Use the modifed Weber-Fergusson incision along the philtrum, nasal subunits with "v" in the nasal foor and lip mucosa—meticulous layered closure in layers and accurate alignment of the vermillion border.

*Delayed bone healing (maxillary swing)*: Minimal soft tissue elevations along the osteotomy sites, pre-plating prior to completion of osteotomy, use fne saw blades and bur and copious irrigation.

#### **Clinical Tips**


#### **85.3 Nasal Swing**

This provides access to the nasal cavity, ethmoids and nasal roof and can be considered for bilateral lesions, when the nasal skin/bones can be preserved. Currently, with the widespread use of endoscopic techniques, its role, as a "sole" access to these lesions, is restricted. It is often used for additional access, as part of a wider resection.

A modifed Weber-Fergusson incision is made respecting the nasal subunits, and allowance is made for a transverse medial extension along the glabella skin crease (Fig. 85.3a). The soft tissues are retracted laterally and superiorly to obtain exposure of the nasal bones, frontal process of the maxilla and the piriform rims. The soft tissue overlying the nasal bone is left undisturbed. Exposure of the contralateral nasal bones is achieved by undermining in a subperiosteal plane. A fne bur/saw is used to make the bone cuts along the frontal process of the maxilla and across the nasal bones (Fig. 85.3b). The contralateral nasal osteotomy is carried out with fne osteotomes, if necessary, through separate stab incisions. The osteotomy sites are prelocalised with low-profle bone plates, removed and replaced during the procedure. The underlying nasal mucosa and soft tissue along the piriform rim are released with a diathermy. The soft tissue incisions and the bone cuts are stepped or staggered.

The nasal septum restricts complete lateral retraction. The septal cartilage is transected with a cutting diathermy—the damp tonsil swab in the other nostril can prevent accidental injury to the contralateral lateral nasal wall mucosa and the facial skin. The 1 cm strut of nasal septal cartilage is preserved along the dorsum and columella to prevent collapse (Fig. 85.3c). The nasal bones and the soft tissues can now be retracted to the opposite side (Fig. 85.3d).

A soft tissue only and soft and hard tissue nasal swing can be combined with a larger midface/craniofacial resection for pathologies involving adjacent structures. The nasal swing can be linked with a frontal craniotomy for resection of tumours that also involve the central compartment of the anterior cranial fossa (Fig. 85.3e, f).

The plates are replaced, and the wound is closed in layers (Fig. 85.3g).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 85.3** Nasal swing. (**a**) Skin marking, respecting the nasal sub units. (**b**) Bone cuts along the frontal process of the maxilla and nasal bones. (**c**) Marking for septal incision preserving dorsal and caudal strut. (**d**) Exposure of the nasal cavity following retraction of the nose.

(**e**) Bone cuts for "nasal/ethmoid clearance" as a part of a craniofacial resection. (**f**) Defect viewed from the cranial aspect following "nasal/ ethmoid" clearance. (**g**) Wound closure following nasal swing

**Fig. 85.3** (continued)

#### **85.3.1 Potential Complications and Solutions (Clinical Pearls)**

*Unsightly scar*: Use the modifed incision along the philtrum, nasal subunits with "v" in the nasal foor and lip mucosa. Carry out meticulous closure in layers and acheive accurate approximation of the vermillion border.

*Delayed bone healing (nasal osteotomy)*: Minimal soft tissue elevations along the osteotomy sites, pre-plating prior to completion of osteotomy, use fne saw blades, burs and osteotomes and copious irrigation.

*Nasal collapse*: Attempt to preserve caudal/dorsal septal strut.

#### **Clinical Tips**


#### **85.4 Per Oral Access**

A signifcant proportion of the oral lesions can be accessed and managed per orally. The use of a solely per oral access is dictated by the location and size of the lesion, the mouth opening and status of the dentition. An appropriately sized mouth prop/gag with cheek and tongue retractors and traction sutures can be utilised to provide the necessary access to safely carry out the procedure (Fig. 85.4).

#### **Clinical Tips**


#### **85.5 Soft Tissue Lip Split**

Lip split incisions to gain additional access to the oral cavity have been in practice for over 150 years. A midline chin incision was described by Roux [17] and subsequently popularised by Trotter [18] in the early 1900s. Further modifcations by Macgregor [19] placed the chin component along the mentolabial fold, and Hayter [20] suggested incorporating a chevron in the vermillion and mentolabial area.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 85.4** Per oral access. Per oral access for excision of a tongue lesion

Soft tissue only lip split can provide excellent access to the posterior buccal mucosa and mandible, for lesions that cannot be safely excised through a per oral or cervical approach. The principle disadvantage of this approach is the need for lip split scar and likely sacrifce the mental nerve; this must be weighed against improved access. The latter is not a consideration if the inferior alveolar nerve has to be sacrifced in the subsequent resection. A lip split through the commissure would have to be considered for tumours located close to the commissure to avoid devascularising the segment between the midline lip split and commissure. This would also be a consideration for composite resections involving the adjacent skin.

A full-thickness vertical incision is made through the lower lip in the midline and extended inferiorly along the midline of the chin/upper neck (Fig. 85.5a). It continues with an appropriately placed low-neck skin crease incision. A "V" can be incorporated in the mucosal aspect of the lower lip to facilitate accurate approximation. The cosmetic outcome with a midline chin incision is excellent and reduces the risk of numbness and ischemia of the ipsilateral chin, associated with a curvilinear incision along the mental fold.

The neck skin fap is raised in a plane deep to the platysma, up to the lower border of the mandible, taking care to avoid injury to the marginal mandibular branch of the facial nerve. The cheek fap is elevated by detaching the platysma from the lower border of the mandible in the subperiosteal plane. More posteriorly, the dissection can be continued superfcial or deep to the masseter muscle (Fig. 85.5b).

Intraoral soft tissue incisions are placed along the gingival crevice or the lower vestibule and are principally determined by the location of the tumour. The wound is meticulously closed in layers, taking care to accurately align the vermillion border.

### **85.5.1 Potential Complications and Solutions (Clinical Pearls)**

*Unsightly scar*: Accurate alignment of the vermillion border and meticulous layered closure.

*Mental and marginal mandibular nerve damage*: Appropriate plane of dissection and identifcation and protection of the nerves.

*Lip necrosis*: Avoid "additional" midline incision for tumours in the commissure region or composite buccal mucosa resections.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 85.5** Soft tissue lip split. (**a**) Skin markings for a soft tissue lip split. (**b**) Exposure following fap elevation

#### **Clinical Tips**


#### **85.6 Visor Flap**

A visor fap can be utilised for lesions in the foor of mouth, tongue and mandible and can be combined with bilateral neck dissections. The incision is marked at an appropriate low-neck skin crease and extends from one mastoid tip process to the other (Fig. 85.6a). The skin faps are raised in the sub-platysmal plane up to the lower border of the mandible, taking care to avoid injury to the marginal mandibular branch of the facial nerve. The periosteum is incised along the lower border of the mandible and a mucoperiosteal fap elevated, taking care to identify the mental nerves. Intraoral mucosal incisions are determined by the location of the lesion, and the mental nerves might have to be sacrifced to obtain further access or adequate margins. The skin faps are retracted cephalad with "penrose" rubber drains (Fig. 85.6b)*.*

When used as a part of lingual release/pull-through procedure to access a foor of mouth/tongue lesion, the mental nerves and labial/buccal soft tissue can be left undisturbed [21, 22]. Resection of the lesions in the anterior foor of mouth along with the mandible results in detachment of the tongue to the mandible. It is essential that the geniohyoid and genioglossus muscles are reattached to the reconstructed mandible to prevent the tongue from falling back. The wound is closed in layers. An advantage of the visor incision is the avoidance of a lip split facial scar, which needs to be weighed against the risk of bilateral injury to the marginal mandibular branch of the facial and mental nerves.

#### **85.6.1 Potential Complications and Solutions (Clinical Pearls)**

*Mental and marginal mandibular nerve damage*: Appropriate plane of dissection and identifcation and protection of the nerves.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 85.6** Visor fap. (**a**) Skin markings for a visor fap. (**b**) Exposure following fap retraction with "penrose" rubber drains

#### **Clinical Tips**


#### **85.7 Transmandibular Approaches**

#### **85.7.1 Mandibular Swing**

#### **85.7.1.1 Lip Split Paramedian Mandibulotomy**

Mandibulotomy to access oral cavity, oropharynx and skull base has been in use for over 150 years, since its initial description by Roux [17] and Trotter [18]. It was popularised by Spiro [23], who suggested a median mandibulotomy, and McGregor [19] described a paramedian location, anterior to the mental foramen. Though various sites and design of the osteotomy have been described, a straight line paramedian mandibulotomy is currently the most widely used option, as it preserves the attachment of the anterior belly of the digastric, geniohyoid and genioglossus muscles and mental nerve. The availability of rigid fxation and fne saws negate the need for step osteotomies and tooth extractions in most cases.

The lip split with a mandibulotomy provides excellent access to the mid and posterior third of the tongue, foor of the mouth, soft palate, tonsillar fossa, oropharynx/posterior pharyngeal wall and supraglottic larynx. It can be extended posteriorly to provide additional access to the infratemporal fossa and the parapharyngeal space with safe vascular control. It can be considered in three discrete stages; lower lip/ chin division, paramedian mandibulotomy and soft tissue elevation on the lingual aspect of the mandible.

A vertical full-thickness incision is made through the midline of the lower lip and extended inferiorly across the midline of the chin/upper neck and continues with an appropriately placed low-neck skin crease incision (Fig. 85.7a). A "V" can be incorporated in the mucosal aspect of the lower lip to facilitate accurate approximation.

The cosmetic outcome with a midline chin incision is excellent and reduces the risk of numbness and ischemia of the ipsilateral chin, associated with a curvilinear incision along the mental fold.

The neck skin fap is raised in a plane deep to the platysma, up to the lower border of the mandible, taking care to avoid injury to the marginal mandibular branch of the facial nerve. Intraorally, the incision through the labial mucosa and

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 85.7** Lip split paramedian mandibulotomy. (**a**) Skin marking for lip split mandibulotomy. (**b**) Mucosal marking for lip split mandibulotomy. (**c**) Lingual subperiosteal tunnel, bone cuts and pre-plating prior to completion of mandibulotomy. (**d**) Lingual crevicular incision and mandible retracted laterally following release of mylohyoid muscle. (**e**) Additional exposure of the infratemporal fossa by tracing the inferior dental and lingual nerves. Defect following maxillectomy and infratemporal fossa clearance (different patients)

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 85.7** (continued)

attached gingiva is designed (stepped), so that it does not directly overlie the planned osteotomy (Fig. 85.7b). The elevation of the periosteum and mentalis muscle should be restricted to allow identifcation and protection of the mental nerve and placement of the plates.

A soft tissue pocket is created by elevating the lingual mucosa off the mandible adjacent to the osteotomy. A periosteal elevator is placed in the pocket, and an osteotomy is carried out between the lower lateral incisor/canine or canine/frst premolar region (Fig. 85.7c). The mandible is osteotomised with a fne saw, taking care to avoid injury to the tooth roots. Occasionally a tooth would have to be removed to facilitate the osteotomy. The mandible is pre-plated prior to completion of the bone cuts, and these are removed and replaced during the procedure. The osteotomy cuts are in a straight line, as a stepped osteotomy neither aids fxation or bone union and can increase the risk of injury to the teeth apices and mental nerve.

Once the mandible is divided, it is gently retracted laterally, and an incision made along the lingual gingival crevice and the mucoperiosteum elevated off the lingual mandible (Fig. 85.7d). The mylohyoid muscle is detached along its attachment to the mylohyoid ridge. Further soft tissue dissection is dictated by the location of the tumour.

If additional access is required to the infratemporal fossa/ parapharyngeal space, it will be necessary to detach the medial pterygoid muscle from the medial ramus of the mandible. In addition, the stylomandibular ligament (at the angle of the mandible) and the sphenomandibular ligament (at the lingula) have to be detached to obtain the best possible access (Fig. 85.7e). The inferior dental and lingual nerve are identifed early and protected and can be utilised as roadmaps to the foramen ovale and skull base. The maxillary artery can also be identifed entering the infratemporal fossa, at the neck of the condyle by following the posterior border of the mandible. Early identifcation and ligation can help provide a relatively bloodless feld for dissection of the infratemporal fossa.

The lingual gingival crevicular incision facilitates easy closure and avoids placement of the suture line at the depth (sump) of the wound. The mandible is held in occlusion, and the plates are replaced accurately to achieve the premorbid localisation. The wound is meticulously closed in layers.

#### **85.7.2 Potential Complications and Solutions (Clinical Pearls)**

*Unsightly scar*: Accurate alignment of the vermillion and meticulous layered closure.

*Mental and marginal mandibular nerve damage*: Appropriate plane of dissection and identifcation and protection of the nerves.

*Delayed bone healing*: Minimal soft tissue elevations along the osteotomy sites, pre-plating prior to completion of osteotomy, use fne saw blades, burs, osteotomes and copious irrigation. Osteotomy ideally in the canine region.

*Damage to adjacent teeth*: Design osteotomy where space allows, use fne instruments and consider extraction.

#### **Clinical Tips**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 85.8** Double mandibular osteotomy. (**a**) Skin markings for double mandibular osteotomy. (**b**) Bone cuts marked and mandible pre-plated. (**c**) Mandibular segment retracted laterally and superiorly to expose deep lobe parotid tumour

#### **85.8 Double Mandibular Osteotomy**

Mandibular osteotomies to access the parapharyngeal region can be broadly divided into those involving the oral cavity (lip split mandibulotomy) and those staying out with the oral cavity. Since it was initially popularised by Attia [24] to access parapharyngeal and pterygomaxillary region, several designs of osteotomies have been described, involving one, two and three osteotomies, variously placed in the paramedian and ramus/condylar region [25].

Double mandibular osteotomy provides excellent access to the infratemporal fossa, parapharyngeal space, deep lobe of the parotid and terminal extracranial internal carotid artery adjacent to the skull base, when the oral cavity does not have to be entered.

A low-neck skin crease incision with submental extension is made (Fig. 85.8a), and the neck fap is raised in the subplatysmal plane up to the lower border of the mandible, preserving the marginal mandibular branch of the facial nerve. The lateral mandible is exposed in a subperiosteal plane and the mental nerve identifed and protected anteriorly. The masseter muscle is detached from the lateral ramus of the mandible up to the sigmoid notch. The anterior bone cuts are fashioned anterior to the mental foramen, between the canine/ lateral incisor or canine/frst premolar teeth roots. The posterior bone cut is made from the sigmoid notch to the lower border of the mandible, posterior to the lingula and inferior dental canal (similar to a vertical sub-sigmoid osteotomy). The mandible is pre-plated prior to completion of the bone cuts (Fig. 85.8b). The plates are removed and replaced during the procedure. Following completion of the osteotomy, the segment of the mandible containing the inferior dental nerve is retracted lateral and superiorly to provide wide access to the parapharyngeal and infra temporal areas (Fig. 85.8c).

Further soft tissue dissection is dictated by the necessity to access specifc parts of the medial mandibular area.

The stylomandibular ligament can be detached from the posterior "condylar" segment to obtain further exposure of the stylomastoid area. The muscular and ligamentous attachments to the styloid process can be detached, and, if necessary, the styloid process is osteotomised to gain addition access to the "post-styloid" space, terminal extracranial internal carotid and the skull base close to the jugular foramen and lower cranial nerves.

This procedure avoids a lip split scar and helps preserve sensation to the lip while providing access to the more "diffcult-to-reach" areas.

#### **85.8.1 Potential Complications and Solutions (Clinical Pearls)**

*Mental and marginal mandibular nerve damage*: Appropriate plane of dissection and identifcation and protection of the nerves. Osteotomies planned to avoid the course of the inferior dental nerve.

*Delayed bone healing*: Pre-plating prior to completion of osteotomy, use fne saw blades, burs, osteotomes and copious irrigation.

*Damage to adjacent teeth*: Design osteotomy where space allows, use fne instruments and consider extraction.

#### **Clinical Tips**


#### **85.9 Zygomatic Osteotomy**

Facial translocation techniques allow modular craniofacial disassembly of the facial skeleton to access "relatively" inaccessible regions of the skull base and nasopharynx. A variety of osteotomies have been described, but with the increased use of endoscopic approaches, the necessity for extensive procedures continues to diminish. Various modifcations of zygomatic and orbital osteotomies in combination with craniotomies has been described since it was popularised by Lesoin [26], Hakuba [ 27] and Sindou [28] to access skull base lesions.

Zygomatic osteotomy, pedicled on the masseter muscle and its subsequent inferior displacement, provides simultaneous exposure of the temporal and infratemporal fossa and orbit. An additional frontotemporal craniotomy can link the middle and anterior cranial fossa and the middle cranial fossa with the infratemporal fossa. The extent of the "zygomatic" osteotomy and the direction of retraction of the temporalis is determined by the location of the pathology. For subcranial lesions, (temporal/infratemporal fossa/orbit), the temporalis is retracted superiorly following a coronoidectomy. For simultaneous exposure of the anterior/middle cranial fossa and temporal/infratemporal fossa/orbit, the temporalis is refected inferiorly. The vascularity of the temporalis muscle can be at risk with both superior and inferior retraction.

The zygomatic body, arch and lateral and inferior orbital rims are exposed via a coronal fap (Fig. 85.1e, g). Meticulous subperiosteal orbital dissection is carried out to protect the orbital contents, which are retracted with thin malleable retractors. The temporalis is detached from the lateral orbit in the temporal fossa. The lateral end of the inferior orbital fssure is identifed in the temporal fossa and orbit with a blunt hook. The bone cuts are made with a fne saw: superiorly at the frontozygomatic suture, infero-laterally from the lateral infraorbital rim through the body of the zygoma towards the inferior orbital fssure and posteriorly just anterior to the articular eminence. A sagittal bone cut is then made in the lateral orbital wall from the temporal fossa aspect, extending from the frontozygomatic suture osteotomy to the inferior orbital fssure (Fig. 85.9a). A more limited zygomatic arch osteotomy can be utilised, when orbital access is not required (Fig. 85.9b). The osteotomy is preplated, and plates are removed and replaced during the procedure (Fig. 85.9b). The cuts are completed, and the zygoma is mobilised and pedicled inferiorly on the masseter muscle.

Exposure to the infratemporal fossa is limited with a zygomatic osteotomy, which restricts its use to benign pathology, when utilised as a sole means of access. It can however be combined with frontotemporal craniotomy to widely access the anterior and middle cranial fossa, optic canal, superior orbital fssure and for combined middle cranial/infratemporal fossa resections (Figs. 85.1h and 85.9c).

**a**

**c**

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 85.9** Zygomatic osteotomy. (**a**) Bone cuts marked for a zygomatic osteotomy. (**a**) Osteotomy above frontozygomatic suture, (**b**) osteotomy across body of zygoma, (**c**) osteotomy across zygomatic arch and (**d**) orbital contents. (**b**) Bone cuts marked and pre-plated for zygomatic

#### **85.9.1 Potential Complications and Solutions (Clinical Pearls)**

*Delayed bone healing*: Preserve masseter attachment, preplating prior to completion of osteotomy, use fne saw blades, burs, osteotomes and copious irrigation.

arch osteotomy (extended to lateral orbital rim due to increased width of orbital rim). (**c**) Tumour exposed in the foor of the middle cranial fossa following temporal craniotomy and retraction of the zygomatic arch and temporalis

*Damage to orbital contents*: Meticulous intra-orbital subperiosteal dissection and haemostasis, fne malleable retractors for orbital retraction and bone cuts under "direct" vision.

*Malposition of lateral canthus*: Accurate bone reapproximation with pre-plating. Consider tagging lateral canthus prior to detachment and subsequent reattachment.

#### **Clinical Tips**


#### **85.10 Lateral and Superior Orbitotomies**

Lateral orbitotomy was initially popularised by Kronlein [29] but with a reverse "C"-shaped incision overlying the temple. A variety of modifcations, principally in the design of the skin incisions, have been described subsequently: lateral canthotomy [30, 31] "S"-shaped incision over the orbital rim, upper eyelid skin crease incision and coronal fap.

Superior/lateral orbitotomies, combined with frontal [32] and pterional [33] craniotomies have been extensively used since their original descriptions in the 1980s.

This approach is useful for lacrimal and lateral/superior/ inferior extra and intraconal orbital lesions and provides additional access for "lookup" approaches to the anterior and middle cranial fossa and for reconstruction with a temporalis fap following orbital exenteration.

A coronal fap is raised, and the zygomatic complex is exposed as described above for the zygomatic osteotomy (Fig. 85.10a). For isolated lesions, a Stallard-Wright [31] "S"-shaped incision extending from the eyebrow, inferolaterally over the lateral orbital rim to the crow's feet skin crease or an upper eyelid skin crease, can be utilised (Fig. 85.10b). The temporalis muscle is refected posteriorly to expose the temporal aspect of the lateral orbit, and the orbital periosteum (periorbita) is elevated from lateral orbital wall (Fig. 85.10c). The lateral end of inferior orbital fssure is identifed with a blunt hook, both within the orbit and the temporal fossa. Perforating blood vessels are identifed and coagulated prior to division.

The orbital contents are protected with a malleable retractor, and the bone cuts are made with a thin saw. Superiorly, just above the frontozygomatic suture; inferiorly, inferior lateral orbital rim along the superior border of the zygomatic arch (the superior border of the zygomatic arch is at the same level as the orbital foor) up to the lateral limit of inferior orbital fssure.

The posterior cut is made with a fne bur/piezo saw in the lateral orbital wall, joining the superior bone cut to the lateral limit of the inferior orbital fssure. This is more easily made from the temporal aspect. The bone cuts are pre-plated prior to removal of the osteotomised segment and plates replaced following completion of the procedure.

The lateral orbitotomy can be combined with a superior orbitotomy and is usually performed in conjunction with a frontotemporal craniotomy. The craniotomy is best performed initially, and the superior orbital wall is delineated from the cranial aspect. With malleable retractors in situ, the superior and lateral orbitotomy can be carried out under direct vision (Fig. 85.10d). This provides excellent exposure of the contents of the superior orbit, superior orbital fssure and optic nerve/canal (Fig. 85.10e). This can also be used for "lookup" approaches to the superior anterior and middle cranial fossa lesions. The bone faps are replaced (Fig. 85.10f), and the wounds are closed in layers. The medial extent of the superior orbitomy can be limited by the extent of the frontal sinus. The supraorbital neurovascular bundle will have to be protected/retracted.

#### **85.10.1 Potential Complications and Solutions (Clinical Pearls)**

*Delayed bone healing*: Pre-plating prior to completion of osteotomy, use fne saw blades, burs, osteotomes and copious irrigation.

*Damage to orbital contents*: Meticulous intra-orbital subperiosteal dissection and haemostasis, fne malleable retractors for orbital retraction and bone cuts under "direct" vision.

*Malposition of lateral canthus*: Accurate bone reapproximation with pre-plating. Consider tagging lateral canthus prior to detachment and subsequent reattachment.

#### **Clinical Tips**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 85.10** Lateral and superior orbitotomies. (**a**) Skin marking for a hemicoronal fap. (**b**) Upper eyelid skin crease incision for lateral orbitotomy. (**c**) Bone marking for superolateral orbitotomy and frontotem-

poral craniotomy. (**d**) Superolateral orbitotomy bone cuts following craniotomy. (**e**) Exposure of the orbital contents following orbitotomy. (**f**) Craniotomy and orbitotomy bone faps replaced

#### **85.11 Conclusion**

Multiple routes are available to the clinician to access the pathology in the craniomaxillofacial region. The technical aspects of the individual procedures are described in detail, along with the potential alternatives and a progressive algorithm. An understanding of the relevant anatomy, a critical analysis of the extent of the lesion, exposure required and potential reconstruction helps in determining the most appropriate choice of procedure. There is no substitute to working within well-functioning teams to obtain the relevant clinical experience.

#### **85.12 Algorithms**

*2. Access to Tongue*

The following algorithms provide a potential sequence that can be considered for progressive access for pathologies in the head and neck region. The algorithms "exclude" endoscopic approaches that can be used in isolation or in combination with open access for lesions especially in the nose, orbit, anterior skull base and retromaxilla.

*4. Access to Maxilla\**

#### 85 Access Surgeries and Osteotomies for the Maxillofacial Region

## *5. Access to Nasal cavity\** Per nasal (small anterior lesion) Lateral rhinotomy (ipsilateral nasal lesion) Nasal swing (soft tissue / nasal bone) – Bilateral lesion, able to preserve skin and nasal bone) Facial degloving approach (Bilateral / inferior lesions, able to preserve nasal Skin Lefort 1 osteotomy (bilateral / inferior lesions) Nasal swing (soft tissue) – Bilateral lesion, able to preserve nasal skin \*With the wide spread use of endoscopic techniques, the need for open approaches as the "sole" access modality continues to diminish.

## *7. Access to Parapharyngeal space (deep lobe parotid / post styloid compartment pathology)* Transcervical Lip split mandibulotomy (oropharyngeal mucosal involvement) Transcervical transparotid Double mandibular osteotomy (no oropharyngeal mucosal involvement)

Common access procedures to the various sitesa


a Excludes endoscopic approaches, which can be utilised alone or in combination with the open approaches

#### **References**


#### **Additional Readings**


#### **Lateral Rhinotomy**

Mertz JS, Pearson BW, Kern EB. Lateral rhinotomy. Indications, technique, and a review of 226 patients. Arch Otolaryngol. 1983;109(4):235–9.

#### **Lip Split**

Rapidis AD, Valsamis S, Anterriotis DA, Skouteris CA. Functional and aesthetic results of various lip splitting incisions: a clinical analysis of 60 cases. J Oral Maxillofac Surg. 2001;59:1292–6.

#### **Double Mandibular Osteotomies**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

**Part XXII**

**Reconstructive Procedures of the Oral and Maxillofacial Region**

## **Soft Tissue Reconstruction of the Maxillofacial Region**

Benjamin Turner, John Collin, and Rui Fernandes

#### **86.1 General Considerations**

The general precept of reconstructive surgery is to assess what tissue and structures are missing and what is available to replace them, ensuring that where possible 'like should replace like'. Hard tissue defects are best restored with hard tissue and soft, soft tissue. Usually skin closest to the defect will give the best cosmetic match. Hard tissue reconstruction falls outwith the remit of this chapter, but where required it should be performed frst to provide the foundation for successful soft tissue reconstruction. Next, muscle and fasciocutaneous tissue should be resuspended from the maxillofacial skeleton to restore muscle function and prevent ptosis of the soft tissues. The aerodigestive tract needs to be isolated from the cranial cavity, deep neck spaces and external skin to reduce the risk of spreading infection, fstula and sinus formation. Finally, the aphorism that form follows function is germane and careful reconstruction of normal anatomy will often meet the dual goals of cosmesis and restoration of function. Anatomical subunits should be respected, and generally if the defect is greater than 50% of a subunit, better results are obtained with removal and reconstruction of the entire subunit such that scars are camoufaged within their boundary lines (Table 86.1).

For any particular defect, the choice of reconstruction can range from simple to complex, along a continuum commonly described as the 'reconstructive ladder'(Table 86.2) [1]. The

Head and Neck Oncologic and Microvascular Reconstructive Surgery, Fellowship, Jacksonville, Florida, USA e-mail: Benjamin.Turner@jax.uf.edu; John.Collin@jax.uf.edu

R. Fernandes (\*)


'reconstructive matrix' has also been described as a development of this linear concept to take into account technical requirements and potential risks to the patient on additional axes (Fig. 86.1) [2].

#### **86.1.1 Healing by Secondary Intention**

Where there has been soft tissue loss and/or the skin is not re-approximated, healing occurs via secondary intention with deposition of granulation tissue (Fig. 86.2). Typically this results in a broader area of scar tissue and is therefore inadvisable at most sites in the maxillofacial region. Superfcial defects of concave subsites (e.g. medial canthus, conchal bowl) or mucosa are the exception and may be left to heal by secondary intention with good cosmetic results.

#### **86.1.2 Primary Closure**

Primary closure describes the apposition of skin edges to permit healing without granulation tissue formation and minimal scaring (Fig. 86.2). Ideally lines of primary closure should coincide with the boundaries of the anatomical subunits (Fig. 86.3), such that the scar is hidden in a natural skin crease or hairline or mimics the natural highlight of the white roll of the lip, for example. Similarly, for ablative procedures involving 50% or more of an anatomical subunit, it is preferred to remove the entire subunit for these reasons. Obviously reconstruction would then entail some kind of tissue transfer. A further consideration is orientation of closure

**86**

B. Turner · J. Collin

Professor, Department of Oral and Maxillofacial Surgery, University of Florida, Florida, USA

Division of Head and Neck Surgery, Jacksonville, Florida, USA e-mail: Rui.Fernandes@jax.uf.edu

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_86

#### **Table 86.2** Reconstructive ladder


**Fig. 86.1** The reconstructive matrix

with respect to the lines of relaxed skin tension that typically run perpendicular to underlying muscle fbres where possible. These two factors may dictate the decision to excise further tissue in a traumatic injury. The temptation to excise and close primarily out with these orientations should be avoided; however, as unless tissue is grossly contaminated or frankly necrotic, a straight surgical scar is usually more prominent than random pattern scars. The generous vascular supply of the face means that it is always best to err on the side of caution and perform minimal debridement such that a maximum of soft tissue is preserved.

Primary closure is appropriate for small defects that can be closed without signifcant tension or distortion of key areas such as the apertures of the mouth, nares and orbit. The latter is particularly sensitive to these effects and can result in ectropion and ocular sequelae if appropriate care is not taken. Techniques such as a creating a superior lateral canthal curve to the Mustarde fap, canthopexy and Frost sutures can be employed to reduce the risk of ectropion.

#### **86.1.3 Grafts**

The third rung of the reconstructive ladder is occupied by grafts, which may be further categorized as simple if composed of a single tissue type—commonly split or full-thickness skin but also mucosal grafts, or composite when containing more than one tissue type. Generally they are autografts, although xenografts and bioengineered material such as porcine collagen (Permacol), Polytetrafluoroethylene, fish skin and dermal matrix (e.g. Integra) have certain utility in maxillofacial reconstruction (Table 86.2).

#### **86.1.4 Flaps**

Flaps may be local, pedicled (regional or distant) or free. Local faps transfer tissue to a defect by advancement and/or rotation and are typically supplied by a random vascular pattern. Axial faps based on a named vessel can potentially pro-

#### Healing by primary intention

©Association of Oral and Maxillofacial Surgeons of India

vide a fap of longer length to width ratio. Examples in the head and neck region include the paramedian forehead fap, nasolabial fap and facial artery myomucosal fap.

Regional pedicled faps are able to provide a far greater area of soft tissue coverage than is possible with local faps in the maxillofacial region, without requiring the facilities and expertise for microvascular reconstruction. They are generally less technique sensitive and susceptible to failure than microvascular free faps; however, partial failure can still be problematic. For example, the pectoralis major myocutaneous fap has been reported to have a partial necrosis rate of up to 29% [3, 4]. Furthermore, while pedicled faps are versatile and can usually provide a good skin match, free tissue transfer can often be a better option.

Free faps offer many reconstructive options and can provide good cosmetic and functional outcomes. They may be sub-classifed according to the tissue they contain and whether the pedicle is a named vessel or from a perforator system. Free faps are available to reconstruct practically any size of defect in the maxillofacial region. Freedom from a pedicle allows them to be placed in any location, native vessels permitting.

**Fig. 86.3** Facial aesthetic units (Also refer Fig. 49.2)

	- 4. Cheek: 4a. Infraorbital 4b. Zygomatic 4c. Buccal 4d. Parotid-masseteric

8. Ear: 8a. Helix 8b. Antihelix 8c. Concha 8d. Earlobe 8e. Retroauricular 9. Scalp

©Association of Oral and Maxillofacial Surgeons of India

Disadvantages of faps include:


#### **86.1.5 Transplantation**

Over recent years a number of partial and total facial transplants have been performed successfully. These cases are rare, requiring extremely careful selection and require a huge amount of resources. When indicated, however, this may be the only option to provide a cosmetic and to some extent functional outcome. Additional factors not associated with other reconstructive techniques, including donor selection, psychology, ethics and long-term immunosuppression require thorough consideration.

#### **86.2 Reconstruction of the Oral Cavity**

The functional roles of the oral cavity are among the most important in the body and are extremely sensitive to alteration resulting from even an apparently small defect. The coordinated action of structures within a relatively small anatomical region are critical for both nutrition (mastication and deglutition) and social interaction (speech and facial expression), two of the most vital activities that determine a patient's quality of life.

#### **86.2.1 Reconstruction of the Lips**

The aim of lip reconstruction should be to restore both function and aesthetics. Careful reconstitution of lip anatomy, such as the white roll, vermilion border and Cupid's bow, are required for a satisfactory cosmetic outcome. Continuity of the orbicularis oris muscle and adequate perioral sensation are needed to maintain lip competence. This is important during mastication and the oral stage of deglutition, particularly with fuids, and to prevent drooling in repose. The size of the reconstructed oral aperture will affect function too. All of these factors will contribute to the aesthetics of the lower third of the face.

The lips are unique in that they represent the transition from cutaneous tissue to keratinized dry and non-keratinized wet mucosa. As a result reconstruction of lip defects is best achieved by using remaining lip tissue when possible. This also often preserves contiguous, innervated orbicularis oris muscle and hence function as explained above.


Therefore, local rotational, advancement and cross-lip faps have become mainstays of reconstruction for larger deformities not amenable to direct or sliding lip closure (Table 86.3).

#### **86.2.2 Reconstruction of the Vermillion**

Deformity of the vermillion and the white roll of the lips is readily apparent to most observers; therefore careful reconstruction is vital for cosmesis. Small superfcial defects that do not involve the underlying orbicularis muscle may be left to heal satisfactorily by secondary intention, although the process is slow (25 days on average) and can result in contracture [5, 6]. For these reasons, primary closure of a small vertically oriented fusiform excision is the preferred option, especially as often the defect will extend just beyond the vermillion, so control of the vermillion border re-approximation is required. Where redundant 'dog ear' mucosal tissue is likely to occur with primary closure of a mucosa only defect, a V-Y island of mucosa can be advanced from the labial mucosa or laterally from adjacent vermillion [7].

Large superfcial defects of the upper or lower vermillion are best managed by resection of the entire vermillion subunit (lip shave) and advancement of a fap of labial mucosa. This provides a close cosmetic match, particularly in older patients. Sensation often returns with this approach; however, atrophy and contracture can be apparent particularly if the depth of the fap is not matched carefully to the depth of the defect. Alternatively, transfer of the vermillion of the opposing lip has been described, either as a single or bi-pedicled mucosal fap. Underlying muscle can be included as a myomucosal fap pedicled on the labial vessels [8]. These approaches require division and inset as a second procedure, arguably for minimal beneft compared with mucosal advancement from the labial mucosa. Reconstruction with tongue [9], buccal mucosal or myomucosal faps can give acceptable results. Finally, anal verge mucosa grafts to the lips has also been described [10].

#### **86.2.3 Reconstruction of the Lower Lip**

#### **86.2.3.1 Defects Up to one Half of Lower Lip Width**

Depending on the laxity of the lower lip, which is mainly related to the age of the patient, most defects of less than one third to half the width of the lower lip can be closed primarily with excellent cosmetic and functional outcomes. The defect is extended inferiorly along a 'v' or shield shape incision. The point of the 'v' can be curved laterally to follow the labiomental groove to camoufage the scar in wider defects. In even larger defects, this groove can be followed on one or both sides of the base of the resection to aid in tissue mobilization. Some surgeons utilize a 'w'-shaped incision at the base of the defect, but this may result in a less cosmetic scar. Defects that involve the commissure can be more challenging as blunting that results may require a further commissuroplasty procedure.

#### **86.2.3.2 Defects Greater Than One Half Lower Lip Width**

Lower lip defects of this proportion are unlikely to be able to be closed primarily without causing unacceptable microstomia.

#### **Lip Switch Flaps**

A reverse Abbe fap (see *upper lip reconstruction* below) can be used to reconstruct larger lower lip defects, whereby a segment of upper lip with the same vertical dimension, but around 50% of the width of the lower lip defect is pedicled

**Fig. 86.4** Bilateral Karapandzic faps for reconstruction of lower lip defect

laterally on the labial artery. To prevent deformity of the upper lip, harvest should only be from lateral to the philtrum. In theory bilateral reverse Abbe faps can be used, although the two pedicles that result make oral intake diffcult until the faps are inset.

#### **Karapandzic Flap**

The Karapandzic fap allows reconstruction of lower lip defects up to 80% of the lower lip width [11], with good preservation of function and aesthetics (Fig. 86.4). Some degree of microstomia and blunting of the commissures is caused, however. Unilateral or bilateral transdermal curvilinear incisions that follow the nasolabial creases allow mobilization and re-approximation of the remaining lower lip [12]. The incision extends through dermis only, preserving the neurovascular supply to the remaining lower lip either side of the defect. This is the main advantage compared with the older advancement faps such as the Gillie's fan fap (Fig. 86.5), which disrupt underlying neurovasculature due to full-thickness incisions.

#### **86.2.3.3 Subtotal Defects**

#### **Cheek Advancement Flaps**

Bilateral horizontal cheek advancement faps where described by Bernard (1852) and von Burow (1853) for reconstruction of large lip defects [13]. Tissue is advanced from the cheek by extending incisions laterally from the commissure and excising three triangles – two lateral Burow's triangles and one triangle around the defect of the lower lip itself. Webster refned this technique for reconstruction of lower lip defects using only partial-thickness incisions along the nasolabial and labiomental creases [14] (Figs. 86.6, 86.7 and 86.8). This concept was further refned

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.5** Gillies fan fap for reconstruction of lower lip defects

©Association of Oral and Maxillofacial Surgeons of India

by Pirgousis and Fernandes for lower lip reconstruction [15] (Figs. 86.9 and 86.10).

#### **Nasolabial Flaps**

**Fig. 86.6** Webster modifcation of Bernard-von Burow fap for lower lip

reconstruction

Fujimori described 'gate' faps that are effectively nasolabial faps, which can be combined with a lower labial mucosa advancement fap to reconstruct the entire lower lip [16]. A similar technique allows reconstruct of the upper lip [17] (Fig. 86.11).

#### **86.2.3.4 Reconstruction of the Upper Lip**

#### **Primary Closure**

Defects of the upper lip are less amenable to primary closure than those of the lower lip. There is relatively less laxity, and asymmetry is more apparent because of deviation or distortion of the philtrum and nasal base. Defects up to around one quarter to one third of upper lip width can still be reapproximated satisfactorily, particularly if laterally situated. The philtrum is less forgiving though and while defects up to around half the width can be closed primarily, there is a tendency for fattening and upwards retraction of the vermillion in this subsite.

#### **Lip Switch Flaps**

The frst report of a two-stage pedicled 'lip switch' fap was by Sabattini in 1838 [18]. The labial artery-based fap was popularized by Abbe in 1898, however, for use in cases of bilateral cleft lip [19]. The lower lip donor site is designed to be half the width of the upper lip defect (to equalized the horizontal discrepancy between upper and lower lips), equal to the height of the defect, and with a laterally based pedicle.

B. Turner et al.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.7** Webster-Bernard-Burrow fap markings prior to lower lip resection

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.9** Fernandes fap incisions following lower lip resection

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.8** Webster-Bernard-von Burow fap following closure

The central lower lip is the preferred donor site, as it is hairbearing in males and leaves the least prominent scar. The white roll should be marked prior to incision and potential obscuration due to bleeding, oedema and pallor. The fap is raised including skin, muscle and mucosa but with preservation of the lateral vermilion incorporating the labial vessels. The fap is rotated and inset, taking care to re-approximate

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.10** Fernandes fap following closure

the orbicularis oris muscle and align the white roll (Fig. 86.12). After 2–3 weeks, the pedicle is divided and the fap inset. For defects of the commissure, Estlander described a similar fap where the commissure is the rotation point, and therefore no secondary insetting is required (Fig. 86.13).

#### **Perialar Crescentic Advancement**

Initially described by Webster [20], a perialar incision can be made unilaterally or bilaterally to recruit lateral tissue for closure of upper lip defects (Figs. 86.14 and 86.15). This technique can also be combined with an Abbe fap to recon-

**Fig. 86.12** Abbe fap for upper lip reconstruction. (**a**) Defect and fap markings. (**b**) Flap inset prior to division of

pedicle

©Association of Oral and Maxillofacial Surgeons of India

struct the philtrum when defects involve the midline of the upper lip.

#### **Reverse Karapandzic**

Incisions following the melolabial groove upwards to join the superior margin of an upper lip defect can be used to advance lateral tissue in a similar fashion as the Karapandzic fap does for closure of lower lip defects.

#### **86.2.3.5 Commissuroplasty**

Most of the reconstructive techniques described above result in blunting and rounding of the oral aperture. The simplest way to correct this is to make a horizontal full-thickness incision through the blunted commissure, extending laterally to correspond with the position of the contralateral normal commissure. Epithelium superior and inferior to the incision is excised and labial mucosa advanced from intraorally to recreate the vermilion (Fig. 86.16). An alternative method was described by Gillies and entails excision of a triangular segment of skin lateral to the rounded commissure, to a point comparable with the normal side. A vermilion fap from the opposite lip is then raised and rotated into this and a mucosal fap advanced to reconstruct the vermilion of the donor site (Fig. 86.17).

#### **86.2.3.6 Total Lip Defects**

A combination of the techniques presented above can be employed to reconstruct total defects of one or other lip. Increasingly, free tissue transfer is used instead, however. The most commonly used fap for this purpose is the radial free fap (Figs. 86.18 and 86.19). This is mainly due to the thin, soft, pliable tissue offered and reliable, long pedicle. **Fig. 86.13** Estlander fap for reconstruction of defect involving commissure. A medially pedicled fullthickness fap half the width of the defect is raised from the upper lip and inset into the lower lip defect

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.14** Perialar crescentic fap to reconstruct upper lip defect

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.15** Perialar crescentic fap after closure

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.17** (**a**–**c**) Gillies commissuroplasty. An area mirroring the normal commissure is de-epithelialised (dashed lines, **a**). Vermillion is raised from the lower lip and inset into the de-epithelialised upper lip (**a**, **b**). The lower vermillion is reconstructed with a mucosal fap raised from the labial mucosa (**b**, **c**)

©Association of Oral and Maxillofacial Surgeons of India

There is also the option to include palmaris longus tendon harvest [21]. This can be used as a sling between the commissures, or to the malar periosteum to improve lip form and oral competence. Alternatively, the fexor carpi radialis tendon or a nonvascularized fascia lata graft can be utilized for the same purpose. Coaptation of the lateral antebrachial cutaneous nerve to the mental nerve has been described to restore sensation to radial fap reconstruction of the lower lip [22]. Other free faps that have been employed for total lip reconstruction include the gracilis for the lower lip [23–25] and temporal scalp for upper lip defects [26, 27].

#### **86.3 Buccal Mucosa and Cheek**

The main function of the cheek is to hold food between the occlusal surfaces of the teeth during mastication. Inadequate reconstruction can lead to excess tissue that interferes with mastication or insuffcient tissue and scarring that results in trismus. Where possible the parotid duct should be repaired and/or re-sited in the buccal mucosa if involved in the defect or reconstruction to prevent obstructive parotitis. Small buccal mucosa defects can be closed primarily, but larger mucosal defects often beneft from reconstruction with a split-thickness skin graft or ipsilateral buccal fat pad [28]. As size and depth of the defect increases, the use of regional faps described in the part of this chapter that addresses foor of the mouth defects should also be considered. The radial forearm fap is the most commonly used fap for reconstruction of intraoral buccal defects due to its pliability and lack of bulk (Figs. 86.20 and 86.21). Thicker and more extensive defects may beneft from an anterolateral thigh fap, depending on the patient's body habitus. Full-thickness cheek defects often require reconstruction of both the intraoral and extraoral surfaces. A combination of techniques may be employed, for example, a regional or free fap for the skin and a split-thickness skin graft for mucosa, but often it is best to consider reconstructing with a folded or dual paddled fap. Both radial forearm [29] and anterolateral thigh [30] free faps are well suited for bi-paddled designs. The frst is more pliable and thinner; the second can be made larger and confers less donor site morbidity, as it can generally be closed primarily. The portion between the paddles is deepithelialized where it will lie within the substance of the cheek. Alternatively, if the lip is involved in the defect, the intervening tissue can instead be used to reconstruct the lip. Obviously this will be a static repair and will therefore have an effect on oral competence.

Full-thickness cheek defects often involve the buccal or marginal mandibular branches of the facial nerve, with con-

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.18** (**a**) Design of RFFF for lower lip reconstruction. (**b**) RFFF after inset to subtotal lower lip defect

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.19** Late postoperative appearance of RFFF reconstruction of subtotal lower lip defect

sequent paralysis of the lower face. A detailed description of facial reanimation is outwith the scope of this chapter; however the methods can broadly be categorized as either static or dynamic. Static reanimation includes gold or platinum weights or springs to aid upper eyelid closure and resuspension of the oral commissure to deep temporal fascia with palmaris longus, fascia lata, acellular dermal matrix, PTFE or polypropylene [31]. Dynamic reanimation involves either

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.20** Buccal mucosa defect

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.21** RFFF inset to reconstruct buccal mucosa defect

the reinnervation, usually with nerve grafts or the interposition of innervated muscle, commonly temporalis transposition or a gracilis neuromuscular free fap [32].

#### **86.4 Floor of Mouth**

The foor of the mouth comprises the myomucosal diaphragm that extends from the ventral surface of the tongue, bounded anteriorly and laterally by the lingual aspect of the mandibular gingiva and posteriorly by the retromolar trigone. This inferior limit of the oral cavity provides a reservoir for food during mastication, while the muscles are also active during deglutition. The mylohyoid, geniohyoid and anterior digastric muscles raise the aerodigestive tract anterosuperiorly during swallowing, anchoring the tongue and increasing the diameter of the fauces. At rest the same muscles, particularly genioglossus, prevent upper airway compromise by posterior displacement of the tongue: an important consideration when reconstructing this region. Finally, mobility of the tongue during speech, mastication and swallowing depends on adequate anterolateral separation from the mandible, and therefore reconstruction should also aim to recreate the lingual sulcus and prevent ankyloglossia.

One commonly employed method to reconstruct foor of mouth defects is the submental artery island fap, frst described by Martin et al. in 1993 [33]. It is easily raised with minimal donor site morbidity to provide a large and reliable paddle. The pedicle is up to 8 cm in length, and cutaneous dimensions up to 7 × 18 cm can be harvested, suffcient to reconstruct most pure foor of mouth defects. It confers less donor site morbidity than the main alternative of a radial forearm fap; often there is even a cosmetic improvement in the patient's soft tissue profle. The main concern with the use of this fap is in the oncological setting is due to potential compromise of nodal dissection in level 1. In one small series, four of nine patients undergoing SIF suffered local or regional recurrence thought to be attributable to incomplete nodal harvest [34]. On the other hand, Howard et al. found that in 50 patients undergoing SIF, all with clinically negative level 1 nodes, none experienced recurrence attributable to the fap [35]. It is generally accepted that the fap is contraindicated in necks with clinically positive nodes, particularly in level I. A history of radiation is a relative contraindication, though good outcomes have been described despite this [36, 37]. Finally, since the submental vessels arise from the facial vessels, the fap cannot be performed in patients who have undergone a neck dissection with sacrifce of the facial vessels. In such patients or where tissue is required outside previous radiation felds, the infrahyoid island fap [38] is an alternative of similar size and character to the SIF. Supraclavicular island (Fig. 86.22) and pectoralis major faps are also well-proven options that generally lie outside any previously operated or radiated feld. They have broad pedicles, which unless skeletonized can introduce excess tissue into the defect or the tunnel from donor site. A radial forearm free fap may therefore be preferred, providing a thin, supple reconstruction with negligible pedicle bulk (Figs. 86.23 and 86.24).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.22** SCIF inset to reconstruct foor of mouth defect

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.23** Design of RFFF for foor of mouth defect

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.24** RFFF reconstruction of foor of mouth defect demonstrating good tongue mobility

#### **86.5 Tongue Reconstruction**

Adequate tongue function requires interaction between sensory and motor components of both voluntary and involuntary nervous systems to achieve intelligible speech, mastication and swallowing. Therefore tongue defects have a signifcant effect on quality of life compared with other oropharyngeal structures, proportional to their volume. Tongue reconstruction that recreates the biomechanics of the healthy tongue leads to better function and even cortical adaptation to the neotongue [39]. In terms of speech, the ability for the anterior tongue to contact the palate is particularly important. Speech therapy following tongue reconstruction should be considered as it can improve proprioception of the reconstructed tongue and facilitate cortical plasticity.

#### **86.5.1 Primary Closure**

Small volume defects of the free oral tongue can often be closed primarily with satisfactory outcomes (Figs. 86.25 and 86.26). As the area of the defect increases, the option of healing by secondary intention should be considered as this can result in a more natural tongue morphology, while dehiscence is often the natural course for primary closure in any case.

#### **86.5.2 Pedicled Flap Reconstruction**

Tongue defects can be reconstructed with a variety of pedicled faps, often utilized when free tissue transfer is precluded. Prior to development of free tissue transfer, the pectoralis major and deltopectoral fap were common options, with the facial artery myomucosal fap an alternative for smaller volume defects. There has been a renaissance in the use of other regional faps over recent years, such as the submental (Figs. 86.27 and 86.28), supraclavicular, trapezius and infrahyoid island faps.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.25** Superfcial defect of lateral tongue

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.26** Primary closure of lateral tongue defect

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.27** Submental fap prior to reconstruction of lateral tongue defect

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.28** Late postoperative appearance of submental fap reconstruction of left lateral tongue

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.29** RFFF to reconstruct right hemiglossectomy

#### **86.5.3 Free Flap Reconstruction**

Tongue reconstruction with a microvascular free fap is usually recommended to restore form, resist contractures and tethering in defects greater than a quarter of the original tongue size [40]. The fap should be designed to recreate premorbid morphology in all three dimensions as far as possible.

The radial forearm free fap is the workhorse of tongue reconstruction for good reason (Fig. 86.29). It provides thin, pliable, soft tissue and large-calibre vessels of consistent

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**Fig. 86.30** Folded ALT fap for glossectomy reconstruction prior to pedicle division

anatomy and excellent length for microvascular anastomosis. Harvest can be simultaneous with resection and presents limited morbidity. The lateral antebrachial cutaneous nerve can be coapted to the lingual nerve to provide a sensate fap with some evidence of improved function and resistance to atrophy [41]. Defects greater than three quarters of the tongue may beneft from reconstruction with tissue of greater substance such as an anterolateral thigh (ALT) or rectus abdominis free fap. ALT harvest results in a more easily hidden scar and potential sensory loss is less troublesome. Total glossectomy reconstruction is particularly challenging. Recreation of three-dimensional morphology is critical, with emphasis on height and a tip protruberance, to facilitate speech and swallowing [42] (Figs. 86.30 and 86.31). A fap that is around one third greater than the defect is recommended to achieve this aim due to inevitable atrophy. Hyolaryngeal suspension should also be considered as an adjunct, to reduce the risk of persistent laryngeal aspiration [43].

#### **86.6 Palatal Soft Tissue Defects**

Simple mucosal defects overlying the hard palate can be left to close by secondary intention. Although the process is sometimes prolonged, pain and remucosalization can be aided by an acrylic cover plate retained by bone screws or dental cribs. Buccal mucosa with or without buccal fat pad can be advanced to repair palatal mucosa if the adjacent alveolus is edentulous. Palatal mucosal faps, facial artery myomucosal faps, temporalis or temporoparietal faps and tongue faps are alternatives. Functional reconstruction of the soft palate is diffcult, but uvula, posterior pharyngeal wall or folded radial free faps are options to consider.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.31** (**a**) ALT fap inset for glossectomy reconstruction. (**b**) Late postoperative appearance

#### **86.7 Facial Reconstruction**

The aims of facial reconstruction differ from those of oral reconstruction. While the emphasis in the latter case is on function, without neglecting cosmesis, the priority here is reversed. Besides the disfgurement itself, patients will often suffer signifcant and irremediable social detriment due to inadequate facial reconstruction. Cosmetically acceptable results require a detailed understanding of facial anatomy. This is best considered in terms of the facial aesthetic units [44] (Fig. 86.3). This approach was frst described by Gonzales-Ulloa [45–48], who demonstrated that scars can be hidden in the natural lines dividing units from one another. Menick later discussed the importance of human perception in reconstruction [49].

#### **86.7.1 Forehead Reconstruction**

The forehead comprises midline and paired median, lateral, temporal and brow subunits (Fig. 86.32). Small defects can be closed primarily parallel to horizontal RSTLs that run perpendicular to the underlying frontalis muscle fbres. The defect can be extended to an ellipse or with terminal

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**Fig. 86.32** Aesthetic subunits of the forehead

M-plasties to achieve this. Midline defects may be closed vertically with acceptable results, particularly in the aged face. Undermining and careful closure of the galeal layer is important when closing larger defects primarily.

Split or full-thickness skin grafts can be used for large defects, although there will be a mismatch with the native skin particularly if split thickness. An alternative is tissue expansion either to provide full-thickness skin from a site such as the supraclavicular fossa or locally to provide tissue for a local fap.

Reconstruction of the forehead with local faps usually has a better cosmetic outcome than skin grafts. Unilateral or bilateral horizontal 'H' advancement faps work well, as does an 'A' to 'T' fap at the hairline. Finally, large forehead and scalp defects can be reconstructed with free tissue transfer. With this option, often the best cosmetic results are achieved with a radial fap or latissimus dorsi muscle fap combined with a skin graft.

#### **86.7.2 Eyelid Reconstruction**

The eyelids are of critical importance in protecting the globes and preventing loss of vision through exposure keratitis. The main goals of reconstruction are therefore to recreate a lid that lies passively against the globe without ectropion or entropion and permits full eye closure (Table 86.4). Both the upper and lower eyelids have a bilaminar structure, which has relevance to reconstructive options. The anterior lamella is composed of the thinnest skin in the body and underlying preseptal orbicularis oculi muscle. The posterior lamella is comprised of the tarsal plate and conjunctiva. The tarsal plates impart some rigidity to the eyelids and contain meibomian glands to produce the lipid component of tears. They are around 25 mm in width and 1 mm thick, with the upper plate 7–12 mm and the lower plate 3–4 mm in height. The upper tarsal plate is attached to the levator palpebrae superioris (oculomotor innervation) muscle via the levator aponeurosis and sympathetically innervated Muller's muscle. The lower plate is attached to orbital septum rather than an aponeurosis.

The orbicularis oculi muscle has three parts. The preseptal and pretarsal components are active in blinking, promoting lachrymal fow from gland to canaliculi and insert into the canthal tendons. The outermost orbital component is involved in voluntary eyelid closure and does not insert into the canthal tendons. There are two preaponeurotic fat pads present in the upper lid and three post septal fat pads in the lower lid (nasal, central and lateral). They are separated by fbrous septa, plus the inferior oblique muscle between nasal and central lower fat pads.

**Table 86.4** Aims of eyelid reconstruction


#### **86.7.2.1 Healing by Secondary Intention**

Small superfcial defects limited to the anterior lamella may be left to heal by secondary intention particularly in the medial canthal region where the nasal bones resist scar contracture and therefore ectropion. This approach should generally be avoided in central or lateral lower eyelid defects due to the high risk of cicatricial ectropion.

#### **86.7.2.2 Primary Closure and Grafts**

Small defects not involving the ciliary margin can be closed parallel to relaxed skin tension lines if lagophthalmos does not result. For larger defects confned to the anterior lamella, full-thickness skin grafts from the opposing lid are ideal, providing a good match with minimal hair and resistance to the contraction associated with split-thickness grafts.

If the defect involves the ciliary margin, primary closure is possible up to one third of the lid width. Typically a 7/0 resorbable vertical mattress suture though meibomian gland orifces is used to align the ciliary margin, the tarsal plate is closed with 6/0 resorbable sutures and fnally skin with 6/0 fast resorbing sutures (Fig. 86.33). Conversion to a pentagonal defect with squaring of the tarsal defect and a slight temporal slant to the anterior lamella portion can be helpful to prevent notching of the ciliary margin. A lateral canthotomy and superior or inferior cantholysis can help recruit lateral tissue. Care must be taken to appose both the tarsus and skin to avoid notching of the ciliary margin.

#### **86.7.2.3 Local Flaps**

Full-thickness defects up to 60% of the lower lid width can be repaired with a Tenzel fap [50] (Fig. 86.34), which rotates and advances tissue from the lateral canthus. Alternatively defects of this size can be repaired with a tarsoconjunctival graft and musculocutaneous advancement fap or a Hughes fap [51] (Fig. 86.35). The latter method is a two-stage procedure that involves a pedicled tarsoconjunctival fap from the upper lid covered with skin grafted from one of the upper lids. The pedicle is divided after 4–6 weeks. To prevent entropion of the upper lid, 3–4 mm of tarsus should be preserved. This method in reverse has also been described to repair defects of the upper eyelid [52]. A cervicofacial (Mustarde) fap can also be combined with a Hughes fap, free tarsoconjunctival or palatal mucosa or nasal septal graft to reconstruct lower lid defects.

Defects one third to one half the upper lid width can be repaired with a reverse Tenzel fap or sliding tarsoconjunctival fap (Fig. 86.36) and skin graft. Larger defects can be repaired with a Cutler-Beard fap [53] that transfers an infratarsal fullthickness lower lid fap underneath a bridge of preserved lower ciliary margin (Fig. 86.37). The pedicle is divided after 6–8 weeks. Interposition of a cartilage or dermal matrix graft between the lamellae of the fap can improve the form of the reconstructed upper lid [54] (Table 86.5).

**Fig. 86.33** (**a**–**d**) Primary closure for small defects involving the ciliary margin. A vertical mattress resorbable suture is placed through the meiobian duct orifce region (**a**), to oppose the ciliary margin (**b**). The muscle (**c**) and skin (**d**) are then closed in layers

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Tenzel flap

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**Fig. 86.34** (**a**–**c**) Tenzel fap to advance lateral tissue into lower lid defect. A superiorly curved incision is extended laterally through the lateral canthus (**a**) to allow advancement of a partial thickness fap and remaining lateral lid to close a lower lid defect (**b**). Excess skin inferior to the defect is excised in the manner of a Burow's triangle

**Fig. 86.35** (**a**–**d**) Hughes tarsoconjunctival fap from upper lid to reconstruct lower lid defect. A lower lid defect (**a**) is reconstructed with a superiorly based tarsoconjuctival fap raised from the deep aspect of the upper lid (**b**–**d**). The fap is covered with a skin graft from one of the upper lids and the pedicle divided after 4-6 weeks

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#### **86.7.3 Ear Reconstruction**

(Also refer Chap. 35)

The external ear is a relatively isolated aesthetic unit with its own complex subunit anatomy (Fig. 86.38). Reconstruction requires attention to shape, angular orientation with respect to the adjacent skull, and symmetry with the contralateral ear [55]. Of these three points, the last is the most important. Finally, the reconstructed ear should serve as support for spectacles or hearing aids (Table 86.6).

The major constitutive subunits, working from peripheral to central, are the helix, scapha, antihelix and concha (subdivided into cymba and cavum). The tragus, antitragus and lobule are less critical to overall auricular aesthetics, as a defect involving these subunits has minimal effect on the shape of the remainder of the external ear.

Orientation with respect to the skull follows these general guidelines [55]:

1. Auricular height = distance between lateral orbital rim and root of helix at the level of the brow.


The following will concentrate on helical defects, since the helix is the most common site, and many lesions centred in other regions will extend to involve it as well [56]. The classical reconstructive ladder is somewhat modifed for defects of the ear. For defects overlying intact perichondrium, a full-thickness skin graft is the optimal technique, rather than primary closure [55]. Alternative approaches must be used when perichondrium has been resected, as denuded cartilage will not support a skin graft. If the defect exposes cartilage in an area where it can be resected without altering the shape of the ear, it should be resected down to the opposing perichondrium, which should be covered with a skin graft [55]. The retroauricular skin is the best colour match, and the scar at the donor site is well hidden by the ear.

**Fig. 86.36** (**a**–**d**) Sliding tarsoconjunctival fap for upper lid defect repair. An upper lid defect (**a**) is repaired with a superiorly based tarsoconjunctival fap raised from the adjacent remaining lid (**b**). The fap is

Resection of shape-determining cartilage requires further subdivision. Small helical defects, ideally less than 1.5 cm, can be closed primarily [57]. Primary closure can be facilitated by the extension of the defect into a wedge excision.

For larger defects, the resulting distortion exaggerates the ear's lateral depth and makes it stand out too far from the skull. Defects between 1.5 and 2.5 cm, or roughly one third of the ear's height, can be closed by means of the helical advancetransposed and inset into the defect (**c**), prior to coverage with a skin graft harvested from another eyelid (**d**)

ment fap frst described by Antia and Buch [57–59] (Fig. 86.39). In this repair, the helical sulcus is incised superiorly and inferiorly through the cartilage, but sparing the posterior perichondrium and skin, which then serves as the vascular supply for the fap. A crescent of skin and cartilage can be resected from the scapha anterior to this incision, in order to decrease the size discrepancy between the helix and antihelix and thereby the degree of cupping in the fnal repair [57].

**Fig. 86.37** (**a**–**d**) Cutler-Beard full-thickness lower lid fap to upper lid defect

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#### **Table 86.5** Options for eyelid reconstruction


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**Fig. 86.38** Anatomy of the pinna



Some authors suggest that the Antia-Buch approach is not appropriate for larger marginal defects, since it induces excessive microtia [55]. Others advocate a more aggressive Antia-Buch repair [57], arguing that the microtia will only be noticeable in those exceptional viewing situations when both ears are visible at once. Alternate strategies for a larger defect include adjacent tissue transfer such as a staged tubular pedicled graft [60] or retroauricular fap [61].

For near or complete loss of the external ear, the three options are:


A patient wishing to avoid repeated surgery, or a poor surgical candidate, might be best served by the frst option. Staged autogenous reconstruction was pioneered by Tanzer [62], who described a six-stage approach. This has since been simplifed to a three or two-stage approach by the work of Brent [63] and then Nagata [64]. In summary, a cartilaginous framework is fashioned from costal cartilage, sutured to the remainder of the native ear and reposed beneath the skin as stage one. Stage two refashions the posterior aspect of the ear and establishes the correct angulation away from the skull. Exogenous cartilage substitutes can be used for this approach as well.

Finally, the entire external ear can be reconstructed with a prosthesis attached via adhesive or osseointegrated implants [65–67]. This solution is often best for patients in who the surrounding skin is compromised, for example by radiation or burns [55]. Typically implants require a minimum of 4 mm thickness of temporal bone and connect to the prosthesis via magnets.

#### **86.7.4 Nasal Reconstruction**

Nasal reconstruction must be considered with respect to aesthetic subunits (Fig. 86.40). The nine nasal subunits are the dorsum, lateral walls, tip, ala, soft triangles and columella. A detailed discussion of nasal aesthetics is beyond the scope of this text, but we will describe the approaches most pertinent to trauma and oncologic reconstruction. Only the smallest nasal defects can be closed primarily. However, the available regional fap options are versatile and highly cosmetically acceptable. Lateral defects can often be closed with a nasolabial fap, providing a good colour match and hiding the donor scar in the nasolabial fold [68]. Some blunting of the nasofacial angle can occur particularly if not resisted with deep sutures. Larger defects (>2 cm.) cannot be closed with the limited volume of tissue available, and the dorsum and tip are not accessible with this fap [69]. Other options are the bilobed rotation fap for sidewall defects or sliding Rintala fap for dorsal and tip defects.

Larger defects, and those centred near the midline, are generally best repaired with a paramedian forehead fap. This approach was frst described by Sushruta in the sixthcentury BC [70] and has undergone very little change since. **Fig. 86.39** (**a**–**d**) Antia-Buch helical rim advancement fap. A defect of the helix is repaired by advancement of adjacent helix. Full thickness incisions are made along the inside of the helix +/– a partial thickness incision anterior to the root of the helix (dotted lines, (**a**). A crescent or wedge of scaphal cartilage is excised (**b**) to reduce its circumference and permit approximation of the remaining helix (**c**). Finally, excess skin overlying the scaphal cartilage can be trimmed and the incisions closed (**d**)

©Association of Oral and Maxillofacial Surgeons of India

The fap provides skin of similar character and suffcient size to replace an entire nasal subunit and also a portion of nasal vestibule for alar defects, potentially improving aesthetic outcome [68, 69]. The frst stage involves rotation of a paramedian skin paddle about a narrow pedicle based on the supratrochlear vessels. The fap is generally based on the contralateral vessels, as this produces less torsion of the vessels. The dissection is carried out in the subcutaneous plane at the distal aspect, to provide pliable skin for the repair, but transfers to the subgaleal and ultimately subperiosteal planes as it proceeds proximally towards the pedicle. The paddle is sutured in place, with stents for the nares if necessary. The second stage is carried out approximately 3 weeks after the frst, in order to provide for neovascularization. At this stage, the pedicle is divided and the superior edge of the fap inset. A third stage can be carried out to debulk the fap and is often required for ideal aesthetic outcome [69]. In patients with vascular disease, a greater proportion of the fap can be carried out in the subgaleal plane, and a debulking stage performed before division and inset, in order to decrease the chance of fap necrosis [70]. Reconstruction of alar nasal mucosa in full-thickness defects can be achieved with a

Subunits of contour ©Association of Oral and Maxillofacial Surgeons of India

**Fig. 86.40** Aesthetic subunits of the nose

hinged nasal septum mucoperichondrial fap. Alar rim defects can also beneft from reconstruction with composite grafts harvested from the lobule or helical rim of the pinna.

Defects involving signifcant bony or cartilaginous destruction require repair with similar tissue. Small cartilaginous defects can be reconstructed with nasal septal cartilage [68], but only a limited volume can be harvested without impairing septal integrity and tip support. Grafts may also be taken from the ear or rib; the frst confers less morbidity and has a favourable contour for alar reconstruction, while the second provides a larger volume of cartilage stock [55]. Many potential donor sites are available for bony defects, including calvarium, mandible, iliac crest and long bones (tibia or radius). The dorsal contour is the most important to reconstruct; this can be accomplished with an osseous strut graft [69].

In total or subtotal nasal defects, reconstruction of the internal and external soft tissue and hard tissue requires consideration. Most commonly a radial forearm free fap is employed and can be harvested with a portion of radial bone for use as a dorsal strut [71]. The best cosmetic outcome is generally achieved with this fap when combined with paramedian forehead fap to reconstruct the external skin. Finally, nasal prostheses require less surgery and can provide an excellent match in appearance to the premorbid nose. They can be retained with adhesive, spectacles or osseointegrated implants. Their chief disadvantage is cost, as they must be replaced every 1 to 2 years [68].

#### **86.7.5 Reconstruction of the Extraoral Cheek**

The greater laxity and simpler architecture of the skin of the cheek allows primary closure of most defects, usually by conversion to an ellipse. However, even moderate tension can result in a wide scar or distort adjacent aesthetic units, and ectropion of the lower eyelid is a particular concern here. If primary closure can be achieved to lie along the nasolabial or preauricular creases, this can give an excellent cosmetic outcome. For larger defects, these natural lines can be utilized with cervicofacial rotation fap reconstruction.

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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## **Distraction Osteogenesis of the Maxillofacial Region**

R. S. Neelakandan

#### **87.1 Introduction**

Reconstruction of the facial skeleton is a technique sensitive process for the reconstructive surgeon as the resulting outcome should improve the form and function of the patient. Distraction osteogenesis (DO) can be defned as the biologic process consisting of new bone formation between the bone segment surfaces that are gradually separated by incremental applied traction. It is a technique to which precludes donor site morbidity which is commonly performed to correct long bone deformities but gaining popularity in the maxillofacial reconstructive procedures in the recent times. The recent advancement of DO procedure is the transport distraction osteogenesis (TDO) which involves osteogenesis and histogenesis from the residual host tissues.

Following gradual movement of the transport segment, new bone regenerate formation occurs behind it flling the defect.

**Ilizarov and his colleague's classifed bone transport techniques as:** Monofocal. Bifocal. Trifocal.

The bifocal and trifocal techniques play a major role in regenerating new bone across the continuity defects. TDO involves creating a new bone and soft tissue to cover the defect by moving a segment of bone and new soft tissue formation behind it until the segment docks the receiving host bone. TDO can be achieved by movement of bone segments across the defect (Fig. 87.1a, b, and c).

**TDO is of three types:** Bifocal. Trifocal. Quadrifocal.

Bifocal distraction is the incremental movement of one viable bone segment, trifocal distraction is the incremental movement of two viable bone segments and quadrifocal distraction is the incremental movement of three viable bone segments.

#### **87.2 History of DO**

Distraction osteogenesis (DO), a well-established technique used for several decades by orthopedic surgeons to repair long bone defects has over the past 15 years gained acceptance for correction of various craniofacial deformities. Bone distraction is not a new concept. Distraction was introduced frst by Codvilla nearly a 100 years ago and was subsequently popularized during the 1940s by Ilizarov, who developed a single-stage procedure to lengthen long bones without the use of grafting material. The feasibility of applying Ilizarov's principles to different craniofacial deformities was not considered until several decades after his pioneering work in the peripheral skeleton. In the purest sense, the frst reports of craniofacial DO were in the early 1960s, when rapid expansion of the palate was carried out in growing patients. This practice, however, involved distraction of a naturally occurring physis. Finally, in 1973, Snyder frst described the Ilizarov technique to lengthen a surgical osteotomy of the

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1969

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_87

**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_87) contains supplementary material, which is available to authorized users.

R. S. Neelakandan (\*)

Department of Oral and Maxillofacial Surgery, Meenakshi Ammal Dental College and Hospital, MAHER, Chennai, Tamil Nadu, India

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**Fig. 87.1** (**a**) Bifocal distraction, (**b**) Trifocal distraction, (**c**) Quadrifocal distraction

canine mandible. Interest in craniofacial distraction at frst grew slowly, with sporadic experimental reports appearing over the ensuing two decades. However, in the early 1990s, experimental investigation intensifed following reports from New York University on lengthening of dog mandibles and from Constantino and Friedman et al., who used DO to successfully close canine segmental lower jaw defects. Thereafter, several studies on various animal models demonstrated the application of osteodistraction at a number of different sites, including the mandible, midface, and cranial vault. It was Michieli and Miotti who frst suggested the protocol for mandibular distraction in humans which included a latency period of 1 week after osteotomy followed by activation rate of 1 mm on alternate days and a minimum of 45 days consolidation period of every 15 mm distraction. In 1992, the frst clinical results of craniofacial DO were reported by McCarthy et al. in a small series of patients with congenital mandible deformities. Since then, several larger series with longer follow-up periods have appeared. More recently, the technique has been successfully used for midfacial and upper craniofacial skeletal defects (Table 87.1) [1].

### **87.3 Biology of Transport Distraction**

The adaptive function of bone to mechanical stimuli causing resorption of existing bone and formation of new bone is the continuous remodeling process of the bone tissue and was recognized as the Wolff's law. The principle behind DO is the application of defned mechanical strains to the reparative callus that is formed in the osteotomy gap. It is based on the law of tension stress by which states that gradual traction on living tissues creates stresses that can stimulate and maintain regeneration and active growth of these tissues.

**Table 87.1** The history of DO is long and various researchers has contributed to its development, as summarized below


The sequence of DO is, osteotomy frst, followed by latency period, which is the duration from bone division to the onset of traction. The third phase is the distraction phase which is the time when gradual traction is applied and distraction regenerate is formed, followed by the consolidation period which allows maturation and corticalization of the regenerate after traction forces are discontinued. The last

#### **Sequence of DO**

Osteotomy. Latency period. Distraction phase. Consolidation period. Remodeling phase.

**Fig. 87.2** (**a**, **b**) Traction force applied to the bone segments, slowly pulling them apart, resulting in formation of new bone. (**c**) Line diagram depicting process of TDO in a

mandible requiring

defect

reconstruction for a segmental

stage is the remodeling phase where there is completion of the regenerated bone remodeling [1] (Fig. 87.2a, b).

The entire healing process of TDO is similar to that of a fracture healing process. The osteotomy causes discontinuity of the skeletal segment which triggers an evolutionary process of bone repair. It involves recruitment of osteoprogenitor cells, followed by cellular modulation or osteoinduction, and establishment of an environmental template or osteoconduction resulting in a reparative callus. The latency period is the period from bone division to the onset of traction. It represents the time allowed for reparative callus formation. On the ffth day after osteotomy, a mini-cellular network of growing capillary loops is formed in the medullary canal of both proximal and distal segments in the areas adjacent to the fracture line. This is a stage represented by soft callus where granulation tissue is converted to fbrous tissue by fbroblasts starting in the periphery.

During distraction phase traction force is applied to the bone segments and is slowly pulled apart, resulting in formation of new bony tissues which progressively increases the intersegmental gap. The cartilaginous callus is replaced by new bone formation due to various cellular activities, and this stage of hard callus remains for approximately 3–4 months. However, the normal fracture healing process is interrupted by the application of gradual traction to the soft callus. As distraction begins, the fbrous tissue of the soft callus becomes longitudinally oriented along the axis of distraction. In the second week of distraction, primary trabeculae

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begin to form and the osteoid begins to mineralize. In TDO both membranous and endochondral processes play an important role in the process of new bone formation.

The consolidation period is defned as the time between cessation of traction forces to the removal of distraction device. It represents the time required for complete mineralization of the distraction regenerate. The remodeling period is the period from the application of full functional loading to the complete remodeling of the newly formed bone. The distraction regenerate is remodeled to mature bone during remodeling at a later stage.

#### **87.4 Biology of Bone Transport**

Biologically, bone transport techniques are based on two distinct processes, *distraction osteogenesis* and *transformational osteogenesis*. DO as previously described, is a biologic process of new bone formation between the surfaces of bone segments that are gradually separated by incremental traction. Transformational osteogenesis is a mechanically induced biologic process of pathologic bony tissue transformation into normal bone. Importantly, these two processes occur simultaneously during bifocal bone transport. Distraction osteogenesis occurs between the surfaces of the residual host bone segment and the trailing edge of the transport disc, while transformational osteogenesis occurs between the leading edge of the transport disc and the residual target bone segment (Figs. 87.3 and 87.4a, b).

In TDO the transport segments undergo stress due to compressive forces as well as distraction force. For instance, in bifocal transport, the leading edge realizes compression force, while the trailing edge realizes distraction force, and with trifocal transport, the leading edge of both segments realizes one common compressive force, and the trailing edge realizes two distraction forces one on either side.

#### **87.5 Device Design**

The concept of TDO has been increasingly applied to the craniofacial skeleton in the recent years. Initially used in experimental animal models, then gradually it gained popularity in the clinical setup. After encountering failures with avascularized and vascularized grafts in our patients with mandibular continuity defects, this modality of reconstruction was contemplated in our clinical practice. After treating 22 cases with earlier generation distraction devices, there were certain biological and mechanical problems resulting due to lack of vector control and inadequate tension stress effect. For these reasons various modifcations were made in

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the initial design with an aim to improve the vector control and stability of the device.

The transport distraction device may be divided into three components:


A proper surgical plan and device design should be followed in each case to achieve the desired results. Few factors that are to be considered are the cross-sectional dimension of the transport disc and the length of the defect along with number of teeth in the disc which can be used for prosthetic rehabilitation as well as to monitor the movement of transport disc during the distraction. It is essential to decide if the condyle should be retained or disarticulated to incorporate the condylar component in the device. It is advisable to retain the condyle when possible so as to maintain the natural joint architecture (Table 87.2 and Figs. 87.5, 87.6, 87.7, 87.8, 87.9 and 87.10).

#### **87.6 Biomechanical and Vector Consideration in Mandible and Selection of Device**

The success of distraction osteogenesis is based on biological and biomechanical factors. The biological factors are the length and geometric shape of the defect (straight unilateral posterior/curved across midline), cross-sectional area, and

**Fig. 87.4** (**a**, **b**) Stress realized by transport segment in bifocal and trifocal distraction



density of the transport disc and tension of the soft tissue envelope. The biomechanical factors are dependent on the length and geometric shape of the defect that dictates the selection of straight or curved device.

Every vector is a one-dimensional entity, whereas the desired movements are in most cases two- or threedimensional. The base of the mandible is constituted by fve linear vectors (Fig. 87.11). Two A-P linear vector running **<sup>a</sup> Fig. 87.5** (**a**) frst generation extraoral device. (**b**, **c**) Panoramic radiographs showing the placed frst generation distractor device. (**d**, **e**) Clinical pictures with the frst generation device

©Association of Oral and Maxillofacial Surgeons of India

parallel to the base of the mandible one on either side in the body region, two A-P linear vector running parallel to the base of the mandible in the parasymphysis region, and one horizontal linear vector running again parallel to the base of the mandible in the mid symphysial region. If the defect is along a single vector, it is best reconstructed with straight regeneration, and if the defect is along more than single vector, it is best reconstructed with arched regeneration.

With the advent of various generations of devices for distraction osteogenesis, it is the author's contention that the straight tissue buried distraction device is preferred for unilateral defects, whereas, for bilateral defects crossing the midline, extraoral transcutaneous pin fxation device, either bifocal or trifocal is preferred, as it provides better vector control.

#### **87.7 Classifcation of Mandibular Defects in TDO**

Mandibular defects for reconstruction purpose are classifed as central and lateral defects. Central defects can be either symmetrical or asymmetrical, and lateral defects can be either straight, when the defect is posterior to the second premolar and arched when the defect is from anterior to second premolar (Fig. 87.12a, b).

For reconstruction of central defects, when there is a symmetrical central defect, arched regeneration could be contemplated trifocally with identical transport segment from either side and when there is an asymmetrical central defect arched regeneration could be contemplated quadrifocally with nonidentical transport segments (Fig. 87.13).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.6** (**a**) second generation transport distraction device. (**b**) Panoramic radiograph showing placement of second generation device with a reconstruction plate. (**c**) Clinical picture showing second generation device

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.7** (**a**) Frontal profle view of patient with placement of third generation distractor device. (**b**) Panoramic radiograph showing the presence of third generation distractor device

When it comes to reconstruction of lateral defects, a single-vector defect posterior to the second premolar could be regenerated bifocally, and a two-vector defect anterior to canine could be regenerated either bifocally or trifocally depending upon the availability of horizontal ramus to create transport disc (Fig. 87.14a, b).

The choice of the transport distraction device is dependent upon the site of defect. For defects posterior to second premolar, a straight bar device with or without condylar prosthesis could be used and for defects anterior to frst premolar an arched bar device across the midline could be used. However, a curvilinear push ball device could be used for both the types of defects.

#### **87.8 Indications of TDO**

Transport regeneration is indicated when there is a continuity defect of mandible due to any cause. It is indicated not only as a primary modality of reconstruction following tumor ablative surgery or bone loss due to trauma but also as a secondary modality of reconstruction whenever there is failure with previous reconstruction. It can also be carried out on pediatric patients and even on irradiated patients.

However, it has a limitation when there are no horizontal rami available on either side to create transport segment. Even in such situation, bone grafting and subsequent transportation can be contemplated.

#### **87.9 Presurgical Investigations**

When it comes to investigations, panoramic radiograph and CT will help us to know the exact extension of the lesion and thereby to assume the type of defect we are dealing with. This helps in selection of device.

Stereolithographic 3D models help us in contouring the device exactly along the defect presurgically. This helps in minimizing the working time on the table (Fig. 87.15a, b, c, d).

#### **87.10 Surgical Procedure**

Transport distraction involves creating a transport disc in the residual host bone stump, adjacent to a discontinuity defect or a resection site. The transport disk is then advanced 1.0 mm per day to span the discontinuity defect. As this transport disc advances toward the target host bone segment, callus forms at its trailing edge, which gradually matures and calcifes. Once the transport disc reaches the docking site, the segment is held in neutral fxation until a cortical outline is seen in the regenerate. At the time of distractor removal, a small bone graft may need to be positioned between the transport disc and the docking site because the transport disc becomes rounded and encased with a fbrocartilaginous cap on the advancing front. Osseous union between the disc and docking site necessitates removal of this intervening fbrocartilaginous cap.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.8** (**a**) fourth generation distractor device with an attached reconstruction plate. (**b**) Panoramic view showing presence of fourth generation device without a condylar component. (**c**) Placement of the device in the mandible after a lip split incision

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.9** (**a**) ffth generation arc-shaped device, adapted on STL model. (**b**) Panoramic radiograph showing the placement of ffth generation device. (**c**) Clinical picture of ffth generation device

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.10** (**a**, **b**) Curvilinear ball device for straight and arched regeneration

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.11** Linear vectors in mandibular reconstruction

#### **87.11 Biological Consideration While Designing Transport Disc**

Periosteal preservation is the single most important biologic consideration while designing bone transport, for the transport segment solely depends on periosteal blood supply for its viability. Hence extreme care at every stage—right from making a small incision to minimal periosteal refection to abundant irrigation and water tight mucosal closure over the transport segment—should be ensured.

While designing the transport segment, parallelism of the cut edges of the residual host bone segment, transport segment, and target bone segment should be ensured to achieve even docking of the transport disc to the cut edges of residual target bone segment. This is carried out by taking the vertical osteotomy cut perpendicular to an imaginary baseline that runs between gonion and menton and parallel to maxillary occlusal plane (Fig. 87.16a–e) followed by implant rehabilitation (Figs. 87.17 and 87.18).

#### **87.12 Vascular, Clinical, Radiological, and Histological Features of the Regenerated Bone**

The process of TDO induces tensile stretching of the osteoblast-like cells that alters the local regulation of bone formation and increases the expression of the growth factors. This entire process is vascular-dependent and requires the maintenance of an adequate blood supply. DeCoster et al. in their animal experimental model on transport distraction osteogenesis used injection angiography to study the arterial response of the bone undergoing transport distraction. The angiographic techniques revealed that the transport segment had an intact arterial supply after the osteotomy cut was completed (adhering to surgical principles of TDO) and, also, after transport distraction was activated. They also showed an extensive increase in vessels in distracted limbs of the experimental animals with proximal stretching and distal kinking of the major artery in that limb. Such studies involving major facial vessels during TDO are awaited to be added to maxillofacial literature [2]. Formation of callus can be detected earliest with ultrasonography where it appears as a mixed to hyper echoic area depending upon the degree of maturation. The color Doppler study of the callus demonstrates the quantum of vascularity in the regenerate before maturation [1, 2] (Fig. 87.19).

For radiological examination (Figs. 87.20 and 87.21) regular plain flm radiographs remain the mainstay for screening the TDO during active distraction and consolidation period. Panoramic radiograph, submento-vertex view, lateral oblique mandibular projections, and posteroanterior and lateral skull views may all aid in planning and screening the

**Fig. 87.13** Reconstruction of central defects

Symmetrical Defect

Asymmetrical defect

Trifocally with Identical Transport Discs Quadrifocally with Non-identical Transport Discs

Bifocal Straight Regeneration Bifocal/trifocal Arched Regeneration ©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.15** (**a**, **b**, **c**, **d**) Presurgical planning

**c**

**e**

**Fig. 87.16** (**a**) Incision extending bilaterally to expose the entire mandible inferiorly after layered dissection. (**b**) The lesion resected with clear margins of the preserved bone. The osteotomy should be kept parallel and free from the lesion. (**c**) Osteotomy cut perpendicular to an imaginary baseline that runs between Go and Me and parallel to maxillary occlusal plane. (**d**, **e**) Placement of ffth generation distractor

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.17** Clinical appearance of regenerate of patient from Fig. 87.16

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.18** Implants placed on the regenerated bone after 1 year of the same patient from Fig. 87.16

TDO. These radiographs have their limitation of 2D view of the mutivectorial 3D procedure.

Multi-slice-computed tomographic scans provide a better preview but have the limitation of excessive radiation exposure and scatter due to the distraction device when it is in situ. Elsalanty et al. have extensively experimented on conebeam CT densitometry and three-dimensional histomorphometry in mandibular bone defects reconstructed with bone transport and found that the physical dimensions and architectural parameters of the new bone regenerated remain comparable to the contralateral normal bone in TDO [3]. In their study, the radiographic density comparison was done

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.19** Ultrasound appearance of regenerate

by studying the radiographic attenuation of the regenerate measuring in Hounsfeld units (HU) and comparing it to the outer, inner, and inferior cortices of the bone on opposite side of the mandible (normal bone). Their results showed that the density of the distraction regenerate was comparable to the inner and outer cortices of the control bone, whereas the lower border of the control side of the mandible showed higher density than the regenerate at 1 month of consolidation. The Hounsfeld unit value of the regenerate by TDO was toward the 2000 mark (2000 HU) after a month of consolidation. Microcomputed tomography-based threedimensional histomorphometry used to assess percentage of bone volume, bone mineral density, degree of anisotropy, trabecular thickness, trabecular number, trabecular pattern factor, and trabecular separation showed no signifcant differences between the regenerate and the normal bone after a month of consolidation in all parameters except percent bone volume and the trabecular separation. Percentage bone volume is reported to be signifcantly less, while trabecular separation is signifcantly higher in the regenerate (Fig. 87.22a, b).

Garcia et al. studied the histology of the regenerate and docking site in bone transport in the tibial-diaphyseal defect of adult sheep model and concluded that there is a marked difference between the ossifcation of the docking site and of the regenerate. Intramembranous ossifcation plays a major role in the regenerate, with bone forming from the host bone segment to the target segment. The ossifcation of the docking site shows endochondral and intramembranous ossifcation simultaneously, but the intramembranous ossifcation is limited to rare and small foci [4].

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.21** Osseointegrated dental implants in the regenerated bone

appearance of regenerate

©Association of Oral and Maxillofacial Surgeons of India

Studies done on the architecture and microstructure of cortical bone regenerated with TDO, it has been found that at 12 weeks of consolidation, bone created during bone transport distraction osteogenesis was comparable to native bone in microstructure, architecture, and mechanical properties, and when appropriate time has lapsed, the properties of the regenerate bone were identical to the host bone.

Çakır-Özkan et al. in their study on immunohistochemical analysis of reconstructed sheep mandibles by transport distraction osteogenesis reported strong positive staining for BMP-2, -4, and TGF-β in the cells, and matrix components. These growth factors are believed to enhance the osteogenesis in TDO [5].

#### **87.13 Transport Distraction Osteogenesis in Maxilla**

Ever since the concept of transport distraction on long bone was initiated by Ilizarov and then after it was subsequently introduced on the facial skeleton by Constantino, Fodotov, Wolford, and many others, a lot of articles got published in the world literature affrming the possibility of regenerating quality bone for any length of mandibular defects [6]. It has even become a gold standard in comparison to other modalities of reconstruction. So, the question arises whether transport distraction has a role in maxillary reconstruction. [7, 8]

Cheung et al. were the frst to publish their work on reconstruction of a maxillectomy defect using transport DO in animal experimental model [9]. Our contention is that when transport distraction has become an accepted norm in the reconstruction of mandibular continuity defects, maxilla with its multiple vascular perfusion, rich periosteal supply, and increased cancellous bone is expected to biologically respond even better to the distraction force [10].

Here are a few cases showing our evolution in transport distraction osteogenesis for reconstruction of maxillary defects.

In our maiden clinical attempt at reconstructing a maxillary defect using TDO a straight distraction device was used. The limitation we had with straight bar device was that they were all buccally directed and not conforming to the posterior maxillary arch (Fig. 87.23a, b, c, d, e, f). Subsequently we have successfully employed bifocal transport distraction (Fig. 87.24a, b, c, d, e, f, g, h, i) and trifocal transport distraction (Fig. 87.25a, b, c, d, e, f, g, h) for reconstruction of maxillary defects. Maxillary TDO has also been successful to treat alveolar clefts of maxilla (Fig. 87.26a, b, c, d, e, f, g).

#### **87.14 Advantages of TDO**

Though bone transport may not be possible in all situations, when indicated, it has an edge over other modalities for it doesn't require any specialized hands or equipment, it doesn't prolong the duration of surgery and hence is costeffective. Since no bone grafting is required, there is no donor site morbidity, and there is recreation of alveolar ridge with attached mucosa, buccal, and lingual sulci, all in near normal anatomy. TDO not only regenerates new bone but also every element of soft tissue around it as well. These are summarized in Table 87.2.

#### **87.15 Complications of Bone Transport**

The complications with bone transport in regenerating new bone formation can be discussed under biological and mechanical factors.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.23** (**a**) Straight transport distraction device post-resection defect. (**b**) Transport disc with device. (**c**, **d**) Evidence of histogenesis and osteogenesis in the clinical picture and OPG respectively, after consolidation phase. (**e**) Buccal deviation of the regenerate. (**f**) Rehabilitation with FPD

**Fig. 87.24** (**a**) Arched bifocal regeneration with push ball device. (**b**) Bifocal push ball device in situ—latency period. (**c**, **d**) Transport distraction in progress on same side. (**e**) Transport distraction in progress across midline. (**f**, **g**) Transport disc on docking and consolidation. (**h**, **i**) Post-consolidation and rehabilitation with complete denture

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.24** (continued)

The biological factors are the ones which we have very little control over, whereas the mechanical factors of vector control and bodily movement of transport segment across the midline can be successfully carried out by modifying the device (Table 87.3) [11, 12].

#### **87.15.1 Hypertrophic Regenerate**

This occurs when a single transport segment is designed to regenerate a lengthy defect, when the collagen fibers are overstretched with the central portion of the callus narrowing representing an hourglass appearance in the radiograph (Fig. 87.27). This phenomenon can also occur when the cross-sectional thickness of the transport segment is not adequate to recreate good volume of bone.

#### **87.15.2 Drifting of Teeth**

The teeth in the transport segment and RHBS tend to drift as distraction proceeds due to pull of transseptal fbers across the line of osteotomy. This problem could be overcome by applying a fgure of eight wire to stabilize the teeth in each segment (Fig. 87.28a, b, c).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.25** (**a**) A case of continuity defect across midline following gunshot injury in a soldier. (**b**) CT image of case in 25 a. (**c**, **d**) Trifocal distraction in progress. (**e**) OPG view showing the trifocal distraction in

progress. (**f**) Transport on docking and consolidation. (**g**, **h**) Dental rehabilitation using implants post-consolidation

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.26** (**a**, **b**) A case of maxillary cleft alveolus. (**c**, **d**) Latency period of 5 days. (**e**) Docking of the transport disk on eighth post-op day. (**f**, **g**) Post-consolidation phase rehabilitation

**Table 87.3** Complications of TDO

Biological complications of TDO


#### **87.15.3 Relapse**

Relapse of the new bone regenerate can occur resulting in contracture of the regenerate that could be avoided either by using an acrylic space maintainer or by placing a fxed partial denture immediately after the intended length of bone regenerate is formed across abutment teeth on either segment. It is a wise practice to retain the teeth in the transport disc for this purpose.

#### **87.15.4 Straight Regeneration**

Straight regeneration occurs while transporting the disc across the midline because the collagen fbers does not follow arc architecture of the defect in the midline; instead they get stretched in a straight direction, similar to an elastic band (Fig. 87.29a, b).

Misdirected vector in sagittal and coronal plane can occur when the guidance rod is not kept parallel to the occlusal plane. When such misdirection takes place, it can be allowed to proceed in the same vector until the intended length of bone regenerate is achieved, which could be corrected by callus molding before consolidation of the regenerate. The callus is molded by the rate and rhythm of the distraction and plating is done to achieve stability of the device. IMF is done to keep the occlusion intact on the contralateral side (Fig. 87.30a, b, c, d, e, f).

#### **87.15.5 Midline Consolidation**

The major limitation that we have with this modality of reconstruction is midline consolidation in both mandible and

**Fig. 87.27** Hourglass deformity

maxilla with arched regeneration. The transport segment freezes by the time it reaches a point lateral to midline on the opposite side. The concept of midline consolidation is that as the distraction proceeds beyond canine across the midline, the buccal cortex of the transport segment expresses greater movement than the lingual cortex for the same degree of rotation, as with the long and short arm of a clock suggesting lingual cortical tipping movement less than the required 1 mm per day. This results in lingual consolidation. This can be overcome by further re-distracting the transport segment after performing a lingual cortical osteotomy alone (Fig. 87.31a, b, c, d, e).

transseptal fbers. (**b**) Drifting of teeth. (**c**) Figure of 8 wiring

©Association of Oral and Maxillofacial Surgeons of India

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.29** (**a**, **b**) Straight regeneration not conforming the arch form in mandible and maxilla

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.30** (**a**, **b**) Callous molding and plating done for lingual deviation. (**c**, **d**) Callous molding and IMF done for buccal deviation. (**e**, **f**) Coronal deviation

Maxilla

mandible

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 87.31** (**a**) Midline consolidation in maxilla (**b**) mandible. (**c**) Lingual consolidation as a result of lingual cortical tipping movement less than the required 1 mm per day (left) similar to the long and short hands of a clock. (**d**) Lingual consolidation (*red line indicates the site*  *where callus will be formed after distraction*). (**e**) Re-distraction after lingual cortical osteotomy (*red line indicates the site where callus will be formed after distraction*)

#### **87.16 Role of Exogenous Growth Factors and Platelet-Rich Plasma (PRP) in TDO**

Studies have highlighted that the transforming growth factor-beta, basic fbroblast growth factor, and insulin-like growth factor I are the chief upregulated factors during TDO. These factors are present in the bony matrix, in the cytoplasm of the cells, in osteoblasts, and in a few mesenchymal cells. Distraction at faster rate shows stronger presence of the growth factors but clinically a poor regenerate. An optimum distraction rate, presence of the growth factors, and strict adherence to the biomechanical principles of DO remains the key to successful clinical outcome. Currently, external administration of the exogenous growth factors remains controversial and is a subject of further research, with evidences both for and against it. It may be concluded that the optimum TGF-beta1 is present during the distraction phase in vivo and its exogenous administration may not be recommended based on the evidences from future research. Injection of platelet-rich plasma (PRP) is found to have more favorable clinical outcome to enhance bone healing during distraction osteogenesis. PRP releases plateletderived growth factor and transforming factors (TGF-1 and TGF-2). Platelet-derived growth factors are the initial growth factors present in a wound and initiate connective tissue healing, bone regeneration, and repair. Plateletderived growth factors are a cost-effective and safe alternative to enhance mineralization of the distraction chamber.

In our experience with bioregulators, limited to PRP, we have found that injecting PRP into the site of new bone regenerate chamber after achieving the desired length through TDO, we can reduce the time of consolidation phase by one-third compared to consolidation phase without PRP. PRP has proved to hasten the mineralization of the regenerate and we can achieve the quality of bone that is usually expected in 6 weeks without PRP in 2 weeks' time itself, thus reducing the duration of treatment [13].

#### **87.17 Conclusion**

As we understand, microvascular surgery is not restricted to a particular specialty and is a technique that can be mastered by any surgeons of any specialty. However, it requires a steep learning curve, whereas bone transport doesn't require any additional training or equipment. It involves only the routine plate bending and fxing. So, to conclude, distraction osteogenesis is a continually evolving feld of research and study and an aesthetically and functionally acceptable option for managing extensive maxillomandibular defects and those not amenable to conventional methods. It is akin to "old wine in new bottle" especially brewed to the taste of oral and maxillofacial surgeons, for it is the only contemporary modality of reconstruction that we maxillofacial surgeons can master ourselves and also one that we can call with pride as "our own (Refer Figs. 65.14, 65.15, and 65.17 for TMJ ankylosis cases where distraction osteogenesis has been used as a part of the overall treatment plan)."

**Acknowledgments** Figures 87.1 (a, b, c), 87.2 (a, b), 87.15c, 87.19, 87.22(a, b), 87.28 (a, b, c) are from Neelakandan RS, Bhargava D. Transport distraction osteogenesis for maxillomandibular reconstruction: current concepts and applications. J Maxillofac Oral Surg. 2012;11(3):291–299. Springer, https://www.ncbi.nlm.nih.gov/pmc/ articles/PMC3428445/.

Figure 87.23 (a, b, c, f) from Neelakandan RS, Mathew PC. Intraoral maxillary transport distraction: a casereport. J Oral Maxillofac Surg. 2009 Aug; 67(8):1751–5. PubMed PMID: 19615594. https://doi. org/10.1016/j.joms.2009.03.038. License Number 4613700616915. License date Jun 21, 2019. Licensed Content Publisher Elsevier.

Figure 87.25 (a, c, e) from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5328860/, https://doi.org/10.1007/s12663-015-0861-7; Rajkumar K, Neelakandan RS, Devadoss P, Bandyopadhyay TK. Reconstruction of a Post Traumatic Anterior Maxillary Defect by Transport Distraction Osteogenesis. J Maxillofac Oral Surg. 2017 Mar;16(1):118–122. Springer.

Figure 87.31 (d, e) from S. Neelakandan, R & Bhargava, Darpan. (2011). Transport distraction along the mandibular midline. International journal of stomatology and occlusion medicine. 4. 123–126. https://doi.org/10.1007/ s12548-011-0018-3. (open access).

#### **References**


**Open Access** This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons. org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

## **Hard Tissue Reconstruction of the Maxillofacial Region**

**88**

Srinivasa R. Chandra and Vijay Pillai

#### **Abbreviations**


#### **88.1 Introduction**

The maxillofacial skeleton can be visualised as a threedimensional structure, and its integrity is essential for neurovisceral function like vision, airway conduction, nutritional luminal support, etc. The location and the size of the defect determine the hard tissue reconstruction and the donor site selection.

### **88.2 General Principles** [1]


**Electronic Supplementary Material** The online version of this chapter (https://doi.org/10.1007/978-981-15-1346-6\_88) contains supplementary material, which is available to authorized users.

Nebraska Medicine Fred & Pamela Buffett Cancer Center, Omaha, NE, USA

V. Pillai

Department of Head and Neck Surgical Oncology, Mazumdar Shaw Cancer Center, Narayana Health, Bangalore, India


### **88.3 Principles of Reconstruction**


### **88.4 Terminology**

*Autograft:* Transplant between areas within the same individual.

*Allograft*: Transplant between individuals (same species).

*Xenograft*: Transplant between individuals of different species.

*Isograft:* Transplant between monozygotic twins.

*Osteoconduction* is the phenomenon of bone regeneration which needs a scaffold for ingrowth of capillaries, osteoprogenitor cells and perivascular tissue. The ingrowth of capillaries from the recipient bed causes differentiation of the osteoprogenitor cells and results in the formation of new bone. There are materials which promote osteoconduction as

S. R. Chandra (\*)

Department of Head and Neck Oncology and Reconstructive Microvascular and Oral and Maxillofacial Surgery, UNMC, Omaha, NE, USA

<sup>©</sup> The Association of Oral and Maxillofacial Surgeons of India 2021 1997

K. Bonanthaya et al. (eds.), *Oral and Maxillofacial Surgery for the Clinician*, https://doi.org/10.1007/978-981-15-1346-6\_88

grafts or scaffolds. These can be autologous or alloplastic, homologous, xenogeneic bone particles, bone glass and hydroxyapatite ceramic material.

*Osteogenesis* is the spontaneous growth of new bone. It can either be *spontaneous* from progenitor cells in the area of the bone defect, or it could be *transplanted* osteogenesis arising from grafted progenitor cells.

*Osteoinduction* is auto induction by differentiation of mesenchymal cells from the native bed into osteoblastic tissue. This requires inductive stimulation, either from the grafted bone material (there is natural bone morphogenetic protein release with the resumption by osteoclastic activity on the middle matrix) or by the addition of recombinant bone morphogenic protein-2. This results in recruitment from the surrounding bed of mesenchymal cells, which then differentiate. This is mediated by graft-derived factors, viz. recombinant human bone morphogenic protein-2 (rhBMP-2), in situ BMP, TGF-ß, IGF-1 and IGF-2, BFGF, PDGF.

#### **Clinical Pearls**

Key concept in bone grafting which is a part of hard tissue reconstruction is the extent of ostial induction, ostial conduction and osteogenesis caused by the graft. The main tenet is that only autologous bone graft grafts can promote osteogenesis due to its volume of biocompetent viable cells. Allo- and xenografts do not have osteogenic potential.

#### **88.5 Bone Grafts** [2, 3]

### **88.5.1 Cortical vs Cancellous Grafts**

Cancellous grafts revascularize more rapidly when compared to cortical grafts. For example, cranial bone revascularizes more rapidly than other cortical bone.

Mechanism of healing:

	- Cancellous grafts repair more completely.
	- Cortical bone incompletely resorbed/remodelled

#### **88.5.1.1 Considerations in Usage of rhBMP-2** [4]

In March 2007, the US Food and Drug Administration (FDA) approved the use of rhBMP-2 in maxillofacial surgical procedures for intraoral ridge augmentation.

*Biologic concept*—the mechanism is through osteoinduction by chemotactic osteoprogenitor cellular proliferation and differentiation causing osteoid maturation.

*Technique—*BMP is carried in the acellular collagen sponge (ACS) to the defect where the formed osteoid matures into an ossicle about 6 months after the cycle of resorption and remodelling. There are multiple case reports of allogenic freeze-dried, crushed cancellous bone with BMP and platelet-rich plasma used in large maxillofacial reconstructions. rhBMP-2 is a lyophilized powder mixed with prepackaged sterile water. Concentration of 1.5 mg/mL of rhBMP-2/ACS is advised. For molecular binding the mixture is kept soaked for 15 minutes. To prevent desiccation and protein loss, rhBMP/ACS mixture must be used within 2 hours. Informed consent, warning of swelling and tension-free closure are important considerations.

*Indications*: Approved by FDA—spinal fusions (2002), treating open tibial fractures (2004) and oral and maxillofacial sinus and ridge augmentations (2007).

*Contraindications and precautions:*


#### **88.5.2 Bone Graft Carriers and Fixation Techniques**


#### **Autogenous Bone Donor Sources**

The choice of donor site depends on:


#### **Common Locations of Autogenous Bone Donor Sites**


©Association of Oral and Maxillofacial Surgeons of India

**Fig. 88.1** Bone graft carriers and fxation techniques(**a**–**b**) custom made implants compared to stock prosthesis. (**a**) Custom-built bone graft carrier and plate as patient specifc implant—note that this can be planned for optimal areas of fxation (anchoring the crib to the plate, the

#### **88.5.3 Costochondral Graft**

The costochondral rib graft came into vogue with the concept of transplanting a growth centre to the recipient site in reconstruction. This was initially used for temporomandibular joint arthroplasty and extended to the ramus condyle subunit, as it was a substitute for the growth centre at the condyle and was needed to maintain the growth potential of the joint.

#### **88.5.3.1 Technique**

A submammary incision is placed around the 5th–seventh rib, taking care not to extend beyond to avoid a fail segment. The incision is made in the mid-clavicular line, placed more medially if a costochondral graft is needed. It is deepened down to bone, and a circumferential subperiosteal dissection is done with a stripper. If the cartilage is harvested, a sleeve of periosteum is retained. Subperiosteal dissection is done avoiding pleural damage. Once the graft is removed, inspect the cavity with saline and check for any air leaks. A layered closure is performed with a drain.

#### **88.5.3.2 Indications**

Laryngotracheal reconstruction, nasal reconstruction, auricular reconstruction, facial augmentation in syndromic disorders.

#### **Clinical Pearls**


#### **Pitfalls**


span and width of the screws, etc.). (**b**) The fgure shows a reconstruction bar adapted with stock titanium mesh for carrying a non-vascularised iliac bone graf

#### **88.5.4 Autologous Rib Grafts**

Rib grafts are a good source of corticocancellous membranous bone that can be used as onlay bone grafts for the craniofacial skeleton. Being soft and fexible, it is unable to withstand zones of high stress placement.

The harvest is similar to the costochondral graft; however, leaving the periosteum in situ would allow for regeneration of the rib but would reduce the take of the rib graft.

#### **Pitfalls**


#### **88.5.5 Iliac Crest**

The ilium is a rich source for cortical, cancellous and a combination of corticocancellous bone grafts.

It is primarily utilized for arthrodesis, bony non-unions and alveolar clefts.

The anatomy of the ilium with the dense cortical bone permits grafts for high stress areas like the long bones and hands and also allows for rigid fxation. The outer table has numerous muscular attachments, thus is not preferred. The inner table is commonly harvested.

The iliac crest allows the harvest of large amounts of cancellous bone.

The cartilaginous apophysis in children must not be disturbed as it contributes to the normal growth and development.

#### **88.5.5.1 Technique**

The anterior approach is the most commonly utilized with the incision being placed after careful palpation to ensure the scar lies on the lateral aspect of the crest.

The incision is deepened through the skin, fascia, muscle and periosteum up to the bone. Ideally the inner or medial table is preferred for harvest as it does not cause disruption of the muscle attachments on the lateral side. The bone cuts should be placed preserving the crest so that it is hinged laterally and can be repositioned once the desired bone has been harvested. Maintaining the periosteal attachments of the crest would preserve its blood supply and further fxation would not be needed.

Good haemostasis, meticulous-layered closure with a drain in the subcutaneous tissue can help prevent a postoperative haematoma. It is also common practice to place an epidural catheter into the bed to permit infusion of a long acting local anaesthetic agent for the frst 24 hours.

Most of the disadvantages of iliac bone harvest can be circumvent if the amount of bone graft needed is not too excessive by using the trephination technique.

#### **Pitfalls**


#### **88.5.6 Tibia**

#### **88.5.6.1 Tibial Autogenous Cancellous Bone Harvest**

This was frst reported by Catone [5] in 1992 and is used in maxillofacial bone grafting techniques with a harvest volume of about 25–40 cc from a unilateral site. Harvest can be performed under local or general anaesthesia. The anatomical access to the tibial proximal head can be medial or lateral. Paediatric harvest has been reported, but the growth plate of the tibial plateau should be mature for adequate safety. The contraindications for tibial bone harvest cited are metal prostheses, athletes and history of knee trauma.

#### **88.5.6.2 Technique**

As mentioned the approach can be medial or lateral to the midline patellar tendon. In the lateral approach—Gerdy's tubercle is the bony prominence which is palpated between the midline patellar tendon and the lateral proximal head of the fbula. This bony prominence has the attachment of the iliotibial fascial tract. In the medial approach, there is no signifcant bony prominence, and the only overlying structures to the tibial proximal head are just skin and subcutaneous tissue. Accordingly, an incision on either side goes through the skin and subcutaneous tissue and a self-retaining retractor can be used for retraction.

Once the tibial head is identifed, using a narrow drill with a postage stamp technique, a window is created either supra or subperiosteally. This cortex can be left attached to the periosteum and repositioned at the end of the harvest if cortical bone is not needed. Cancellous bone can be curetted with adequate care not to perforate the superior tibial plateau entering the knee joint. Adequate haemostasis with local cautery should be used to prevent any postoperative haematomas. Deep and superfcial layer closures are performed. No immobilization is recommended, but active weight bearing is avoided for a couple of days. If there is any concern for superior tibial plateau perforation or knee joint violation, an orthopaedic review is mandated.

#### **88.5.7 Cranial Bone** [2]

It is well-known through craniofacial surgery that paediatric skull defects less than 1 cm with an intact pericranium can cause adequate bone healing with osseous regeneration. Calvarial bone grafts can be performed as mono- or bicortical harvest based on the surgeon's competence. Cortical bone shavings are commonly utilized. Just off the midline of the skull sagittal plane, parietal cortical calvarial bone is accessed through skin and the scalp layer incision. Adequate retraction is performed with a self-retaining retractor or assistance. The amount of bone needed is identifed in the subperiosteal plane and marked with round bur of a narrow diameter. Adequate outer beveling is performed (as depicted in the fgure) using a straight fssure bur for a fat osteotomy technique as parallel to the outer surface. Multiple fssuring osteotomies in a parallel fashion can be performed too. The intracortical medulla is carefully traversed through osteotomes and if any small dural perforations are made, they can be covered with artifcial allografts or even haemostatic material. A neurosurgical review is needed in case of dural tear. Haemostasis with bone wax or electrocautery and good pericranial adjacent tissue rotational coverage and closure of the scalp layers leads to reduced postoperative haematomas. The bone harvested can be contoured with a crimping forceps as shown in the fgure (Fig. 88.2a and b).

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 88.2** (**a**) Cranial bone graft harvest with circumfrential trough and beveling. It is ideal to harvest this in the parietal area. Narrow strips are ideal for harvest. (**b**) Cranial non vascular bone graft being contoured with pinch forceps

#### **88.6 Microvascular Free Tissue Transfer**

Most hard tissue grafting using this technique is a 'composite' bone and soft tissue transfer by arteriovenous anastomosis. This transferred bone is usually held in place by plates and/or screws. There is osteogenesis at the interface of the native and grafted bone interface. Current techniques of vascular free tissue using microvascular anastomosis along with minimal donor site morbidity have a success rate close to 98 percent. There is a potential for failure due to anastomotic complication. The vascularized free transferred tissue is resistant to infection and radiation to a degree of volume. There are concepts of creating a vascular envelope and subsequent allogenic or xenogeneic grafting for better osteoconduction by vascular ingrowth.

#### **88.6.1 Osteocutaneous Radial Forearm Free Flap (OCRFFF)**

The popular workhorse fasciocutaneous radial forearm free fap is very well-known for most reconstructive surgeons. Whereas an osteocutaneous variant of this fap is not the 'go to' fap in composite reconstructions. There is signifcant donor site morbidity with about 70% postharvest strength and an increased fracture risk of the distal radius. Distal radius can be reinforced with a prophylactic plate by internal fxation. Figure 88.3 shows osteocutaneous radial forearm free fap for maxillary reconstruction including the orbital rim. Figure 88.4a and b shows radial forearm fap for reconstruction of maxillary and mandibular defects.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 88.3** Osteocutaneous radial forearm free fap for maxillary reconstruction including the orbital rim

#### **88.6.1.1 Indications**

Periorbital, nasal and maxillary subunit reconstructions are the common indications for an osteocutaneous radial forearm free fap. It is a real alternative if other donor sites are not viable.

**Fig. 88.4** (**a** and **b**) Radial osteocutaneous fap as an alternative in mandible (**a**, 3D rendering) and (**b**) maxillary reconstruction (left maxilla CT )

©Association of Oral and Maxillofacial Surgeons of India

#### **88.6.1.2 Technique**

Surface markings of the soft tissue from the distal wrist skin crease as the horizontal line, the radial pedicle and the cephalic vein are outlined. The osseous part of the anterior lateral radius segment between the insertion of the pronator teres and the brachioradialis is harvested up to 10–13 cm in length and about 40 percent in circumference. The distal styloid aspect of the radius should have at least 2 cm to complete a bone plate fxation after the fap harvest. The fascial and muscular periosteal vascularity is retained in harvest. The fap can be raised from the radial or the ulnar side in a subfascial plane. The brachioradialis is retracted laterally protecting the superfcial branch of the radial nerve. A sharp incision is made down to the periosteum preserving the attachment of the intermuscular septum. On the medial side, the fexor carpi radialis muscle is reached and retracted medially so the median nerve is protected. The muscle bellies of the pronator quadratus and the fexor pollicis longus are carefully dissected distal to proximal preserving enough muscular cuff to retain perforators to this segment perfusing from the radial artery in its lateral intermuscular septum. Once the radius periosteum is incised in length noting the curve of radius bone, multiple drill holes are used to outline the osteotomy. A boat-shaped harvest is completed of the cortex protecting the radial vasculature after distal ligation and the muscular perforators to the osseous part. The proximal harvest is completed of the pedicle similar to radial forearm harvest by radial artery and vena comitans ligation. A prebent compression plate is adapted and fxated using bicortical screws across the site of harvest (Fig. 88.5). Osteotomy scan be performed of this

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 88.5** Post-radial osteocutaneous fap harvest with orthopaedic internal bicortical fxation of radius as prophylaxis for prevention of radial shaft fracture

donor segment with close attention for orbital rim reconstruction if needed.

#### **88.6.2 Scapula Free Flap** [6]

Theoretical conceptualization of the scapular fap was frst described by Saijo in 1978 and popularized by Dos Santos [7] in 1979. This scapular system which got described includes a myriad of options based on the subscapular vessels. It can be used as two types of bony composite faps with the utilization of angle of the scapula and the lateral border. The major branches of the subscapular system are the circumfex scapular artery and the thoracodorsal artery. Circumfex scapular artery and its associated vein with the lateral border of the scapula are the classical osseous fap. Scapular and parascapular faps offer the most fexibility with combinations of osseous, muscular, fasciocutaneous free tissue transfer based on the subscapular vascular system. Approximately 10–14 cm of the length with a thickness of 0.5–1.5 cm bone composing the lateral aspect of the scapula and or the angle of the scapula can be harvested.

Figure 88.6 shows the advantage of this fap: independence of soft tissue pedicle in relation to the bone.

It can also be harvested using the angular artery, a branch of the thoracodorsal artery obtaining a longer vascular pedicle and teres major muscle along with the scapular tip. The medial border of the osseous scapular fap has been described; the fexibility of the overlying fasciocutaneous part is not very pliable. The medial border is comparatively narrow even in males for placement of osseointegrated implants.

*Tips for donor site confrmation to the defect:*


Studies have shown good conformance between the scapular tip and the palate. The tip can be used horizontally for a palate and vertically for anterior maxillary reconstruction. There are reports of nonvascular scapular tip being used for orbital foor reconstructions.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 88.6** The osteocutaneous scapular free fap. The great advantage of this fap is the independence of the soft tissue pedicle in relation to the bone

#### **88.6.2.1 Indications**

Composite and complex midfacial defects of the orbit, maxilla, skull base and mandible can be reconstructed using this chimeric fap.

#### **88.6.2.2 Advantages**


#### **88.6.2.3 Disadvantages**


#### **88.6.2.4 Technique**

Clear understanding of the scapular arteriovenous system and its branches composing the circumscapular, descending branch and parascapular vessel anatomy is essential.

The osseous branch of the circumfex scapular artery to the lateral border runs directly into it along with the vein. There is a gap between this and the cutaneous perforator which provides the fexibility of the skin paddle.

Patient can be positioned in a lateral decubitus or prone position for access between the axilla to the midline spine. The author's choice is use of a beanbag under the ipsilateral side and a protected axilla for the contralateral side. To increase the fexibility of the pedicle in relation to the lateral border of the scapula, a scapular or parascapular skin paddle can be based on the circumfex artery. The triangular space is made by the teres minor superiorly and teres major inferiorly, and the long head of the triceps laterally is identifed using a Doppler 2 cm superior to the posterior axillary fold edge. The fasciocutaneous fap elevation is medial to lateral superior to the muscular fascia until the omotricipital triangle is reached. The circumfex vascular pedicle can be followed proximally to the subscapular and axillary arterial system with dissection between the teres minor and major muscles superiorly. The circumfex scapular artery is dissected in the lateral aspect of the scapular border with preservation of the muscular perforators to the bone by medial retraction of the teres minor and inferior retraction of the latissimus dorsi. An incision parallel to the lateral border of the scapula is made through the teres minor and infraspinatus muscle and periosteum. Protecting the vascular pedicle laterally on the glenohumeral joint superiorly osteotomy can be performed using a saw to the desired length with or without the angle of the scapula. Scapular angle can be harvested independently with identifcation of the angular perforators. Adequate care is taken to protect the underlying subscapularis musculature. Teres major muscle is reattached with multiple drill holes to the new border of the lateral scapula donor site to prevent winging. Perioperative drain and postoperative immobilization of the arm after primary closure of the defect site are commonly utilized along with physiotherapy.

#### **88.6.3 Fibula Free Flap** [8, 9]

Taylor et al. frst introduced the fbula fap in 1975 for extremity reconstruction but was reintroduced for mandible reconstruction by Hidalgo. Though designed as an osteocutaneous free fap, the initial reports of unreliability of the skin paddle did not fnd favour in its use as an osteocutaneous fap.

#### **Clinical Pearls**


#### **88.6.3.2 Preoperative Assessment**


Figure 88.7 shows the fbula free fap reconstruction for the left mandibule of the body, angle and ramus. Figure 88.8a– c shows the planning and execution for fbula free fap on a stereo lithographic model. The closing osteotomies are made with measurements using a ruler template; the smallest fbula segment is noted as marginally more than 2 centimetres. In Fig. 88.8b, one can see a sterile ruler held at the lateral fbula harvest with pedicle attached proximally and skin paddle. In Fig. 88.8c, the osteotomized fbula is immobilized to a reconstruction plate at the lower extremity donor site with the pedicle fowing intact.

#### **88.6.3.3 Technique**

Prepare the whole lower limb circumferentially from the calf downwards and the opposite limb for a skin graft. Perform the surface markings of the fbula, with the design of the skin paddle centred along the posterior border that corresponds to the intermuscular septum. Design the skin paddle after the perforators have been mapped out using a Doppler probe. Preserve at least 4–5 cm bone proximally and distally for the stability of the knee and ankle joint and to avoid injury to the

#### **88.6.3.1 Anatomy**

The fbula is a triangular bone in cross section, around 40 cm in length and 1.5–2.0 cms in diameter, articulates proximally with the tibia and distally with the tibia and talus and has dense cortical bone with a small amount of cancellous bone.

*Blood supply*: Dual endosteal and periosteal. The dominant endosteal nutrient pedicle enters posterior to the interosseous membrane at the junction of the upper and middle thirds of the fbula. It is the segmental periosteal blood supply arising from the peroneal artery that permits multiple osteotomies. Average pedicle length depending on the bone length harvested is from 5 to 10 cms with a diameter of 1.8–2.5 mm and venous drainage via paired venae comitantes.

*Skin paddle*: The skin territory for the fap harvest on the lateral aspect of the leg can be up to 25 cm in length and around 15 cms in width and is supplied by perforators from the peroneal system which can be either septocutaneous or musculocutaneous passing through the fexor hallucis longus and soleus. The number of perforators is around 4–8.

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 88.7** Fibula free fap reconstruction for the left mandible of the body, angle and ramus

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 88.8** Maxillary reconstruction planning for fbula osteotomies. (**a**) Planning for fbula free fap on a stereo lithographic model. The closing osteotomies are made with measurements using a ruler template; the smallest fbula segment is noted as marginally more than two centimetre. (**b**), the template being transferred to the fbula area for

superfcial peroneal nerve. Carefully apply a tourniquet and exsanguinate the lower limb.

The incision begins anteriorly on the skin paddle deepened into the subfascial plane over the peroneus longus and brevis and dissected to identify suitable perforators. The incision is extended in a curvilinear manner proximally, and dissection in the lateral compartment is done keeping a cuff of peroneus muscle cobblestoned on the bone.

The next step is the dissection in the anterior compartment of the extensor hallucis longus and extensor digitorum planning the closing osteotomies. You see a sterile ruler held at the lateral fbula harvest with pedicle attached proximally and skin paddle; (**c**) The osteotomized fbula immobilized to a reconstruction plate at the lower extremity donor site with the pedicle fowing intact

longus up to the dense interosseous membrane which is incised. The anterior tibial vessels are seen anterolateral to the fbula and preserved.

Proximal and distal osteotomies are performed using a reciprocating saw, preserving the superfcial peroneal nerve superiorly. Distally ligate the peroneal vessel once the bone is osteotomized.

The posterior compartment dissection is performed between the tibialis posterior and fexor hallucis longus which identify the peroneal vessels. Keep a cuff of fexor hallucis or soleus muscle onto the graft depending on the soft tissue requirement and if the skin paddle is centred along the mid bone.

The posterior design of the skin paddle is made in a similar manner deep to the fascia over the soleus and lateral gastrocnemius preserving the saphenous vein and sural nerve.

Identify and preserve the posterior tibial vessels and tibial nerve 1–1.5 cm medial and parallel to the peroneal vessels.

Perforators to the soleus must be ligated, and additional length of the pedicle can be obtained by a subperiosteal dissection or ligation of the lateral posterior tibial vein.

Shaping of the fbula can be done on the benchside or while still connected with the circulation using either a prebent plate, cutting guides with virtual surgical planning. Closing wedge osteotomies are performed and fxation done.

Donor site closure should be meticulous with good haemostasis; suction drains closing the proximal and distal skin incisions and grafting the remaining donor site. Immobilization with a posterior splint with the ankle in 90 degrees fexion is recommended though not routinely practiced.

Postoperative physiotherapy for the lower limb can commence by the second day and with accompanying gradual weight bearing.

#### **Pitfalls**


#### **88.6.4 Deep Circumfex Iliac Artery-Based Composite Flap or Vascularized Iliac Crest Flap (DCIA)**

Similar to the fbula the DCIA can be planned virtually. Opening osteotomies are performed instead of closing osteotomies in maxilla-mandibular reconstruction (Fig. 88.9a, b, c, d).

This fap can be harvested as an osseous or an osseocutaneous with the soft tissue component of the muscle and skin. This fap is based on the deep circumfex iliac artery and vein with the pedicle length as long as 8 cm with a diameter of the vessels between 1.5 and 3 mm. The iliac crest osteocutaneous free fap (ICFF) was described separately by Taylor [10] et al. and Sanders and Mayou in 1979 and popularized by Urken in 1989 for mandibular reconstruction and by Brown [11] in 1996 for maxillary reconstruction and use of internal oblique muscle [11]. The deep circumfex iliac artery and vein vessels arise from the external iliac vessels. The bone quality and quantity are excellent for both the maxillary as well as mandibular reconstruction.

Maxilla and mandibular segments can be reconstructed using the iliac crest bone based on the deep circumfex branch of the external iliac artery. The authors prefer a harvest using the superior approach in reference to the spermatic cord or the round ligament. Donor site morbidity is not signifcant, and the patient can be supine allowing a two-team approach. Up to 14 cm of bicortical bone with internal oblique muscle can be harvested. The thickness can vary between 0.5 cm and 2.5 cm.

#### **88.6.4.1 Indications and Contraindications**

This composite fap offers optimal volume of bone for endosteal implants as well as segmental mandibular defects with need of reconstruction of the dentate contour. Maxillary palatal contour and the regional complex subunits after maxillectomy can be reconstructed. The relative contraindications for this harvest are inguinal hernia, obesity, hip prosthesis and polyparity in women.

#### **88.6.4.2 Vascular Anatomy**

Just above the inguinal ligament, the deep circumfex iliac artery (DCIA) branches off the posterolateral aspect of the external iliac artery. As it traverses laterally parallel to the inguinal ligament, the ascending branch takes off 1–2 cm medial to the anterior superior iliac spine. This is located between the internal oblique on the transversalis fascia with penetrating perforators. The DCIA has a diameter averaged at 2 mm and a pedicle length of 5–6 cm. Vena comitans accompanies the artery draining into the external iliac vein. The position of the DCIA is about 2 cm inferior to the surface of the iliac crest at the fusion of the transversalis fascia and iliacus muscle. The two variations reported are the ascending branch takeoff in medial relation to the anterior superior iliac spine (1–2 cm versus 2–4 cm) and multiple ascending branch perforators instead of a single identifable ascending branch of the DCIA.

#### **88.6.4.3 Technique**

With the patient supine, a soft hip support is placed and the skin prepped from the midline pubis laterally to the midaxillary line, superiorly from the subcostal margin to the anterior thigh inferiorly with the greater trochanter included in the feld. This includes the planned cutaneous paddle. The cutaneous perforators are concentrated 5 cm lateral to the anterior superior iliac spine and 4 cm superior to the iliac crest midpoint. Only internal oblique musculature for lining of the oral mucosal lining is included. Incision is made in a superomedial elliptical fashion through the Scarpa's and Camper's fascia up to the external oblique musculature. This is identifed in its orientation from the lateral to medial direction, and as this is incised, the underlying 90 degree medial to lateral internal oblique muscle is identifed. The external oblique musculature is included with the osteocutaneous

©Association of Oral and Maxillofacial Surgeons of India

**Fig. 88.9** (**a**, **b**, **c**, **d**) Similar to fbula DCIA can be planned virtually. Opening osteotomies are performed instead of closing osteotomies in maxilla-mandibular reconstruction

fap. The external oblique incision extends from the lateral entirety of the whole length up to the border of the inguinal ligament. The superior part of the fap is retracted and the internal oblique muscle exposed, and the amount of this internal oblique muscle inclusion is identifed for harvest superior to the iliac crest attachment. The internal oblique and transversalis fascia is dissected sharply from the superior lateral aspect to the inferior lateral direction with superior retraction and access. The ascending branch is visualized and dissection is directed to identify the DCIA itself. The ileacus muscle is visualized and preserved based on the pedicle position and harvesting about 2 cm of it. At least 4 cm of the internal oblique muscle is harvested lateral to medial towards the ilioinguinal ligament. The vein runs over the DCIA medially to the external iliac vein.

The bone harvest is performed after detaching the gluteus medius muscle from the outer aspect of the ilium. The medial bone cut is made depending on the inclusion of the anterior crest of the ilium. The template as shown in the fgure (anterior maxillary virtual fnding fgure) is used for making medial and lateral cuts using an oscillating saw. The medial side should be protected for pedicle integrity and peritoneum. If osteotomies are needed of the bony pedicle, they're performed with adequate care to gently greenstick the components.

The abdomen is closed in layers after adequate haemostasis of the donor osseous margins of the osteotomies. Multiple postage stamp holes are made in the bicortical iliac cortex and the residual muscular layers reattached with thicker nonresorbable sutures. And non-resolvable mesh can be used to reinforce the harvested internal oblique defect, and this can be sutured to the cortical holes as described above. The cutaneous closure is performed over suction drainage with multiple layer closure.

The quality and quantity of the bone of this fap are ideal for maxillofacial defect reconstruction. Maxillary reconstruction may need a rather lateralized bony segment harvest to gain adequate pedicle length for anastomosis into the neck. If the mandibular angle is to be reconstructed, the anterior iliac crest is included. An entire hemimandible can be reconstructed using the unilateral iliac crest.

#### **88.6.5 Vascularized Rib Graft**

There are other osteocutaneous faps which are described like posterior costal osteocutaneous fap similar to the harvest of the costochondral part of the rib. These vascularized grafts can be from the right ffth rib in the ventral surface and up to the ninth rib in the dorsal surface. The intercostal vascular pedicle and subcutaneous venous pedicle or even the internal mammary perforators medially are used. The ribs can also be a part of the pectoralis major osteomyocutaneous fap, latissimus dorsi, serratus and trapezius muscular harvest with their pedicles. Of course the isolated rib graft with or without the costochondral graft has been the work horse for temporomandibular reconstruction for decades. The harvest has been documented well in surgical literature over the years.

#### **88.6.5.1 Lateral Femoral Condyle Free Flap**

The choice of this fap is for novelty in maxillofacial surgical needs. Femoral internal condyle with the descending genicular artery and vein as a pedicle can be harvested as free fap. The bony corticocancellous segment measuring up to 8 × 1.5 × 1.5 cm can be harvested [12].

#### **88.7 Conclusion**

In conclusion the hard tissue regeneration and reconstruction have been a primary focus in clinical and research interests for all reconstructive maxillofacial surgeons. The techniques and molecular science have ongoing updates persistently for the optimal and ideal technique. The understanding of intercellular and molecular behaviour of regeneration and grafting procedure is sought by biomedical scientists by research. And with virtual surgery and planning with guided navigation, the future of hard tissue reconstruction is poised for technically predictable results.

#### **References**


#### **Suggested Reading List**


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