Sleep Medicine for Dentists:
An Evidence-Based Overview, Second Edition

To our students, patients, and research associates who have contributed to the progress in dental sleep medicine.

Library of Congress Cataloging-in-Publication Data

Names: Lavigne, Gilles J., editor. | Cistulli, Peter A., editor. | Smith, Michael T. (Michael Timothy), 1967- editor.

Title: Sleep medicine for dentists : an evidence-based overview / edited by Gilles J. Lavigne, Peter A. Cistulli, Michael T. Smith.

Description: Edition 2. | Batavia, IL : Quintessence Publishing Co, Inc, [2020] | Includes bibliographical references and index. | Summary: “This book provides a rapid source of practical information to students, practicing dentists, and scientists about the evolving field of dental sleep medicine”-- Provided by publisher.

Identifiers: LCCN 2019056811 | ISBN 9780867158281 (hardcover) | ISBN 9781647240097 (epub)

Subjects: MESH: Sleep Wake Disorders | Dentistry--methods | Mouth Diseases--complications | Tooth Diseases--complications

Classification: LCC RC547 | NLM WL 108 | DDC 616.8/4980246176--dc23

LC record available at https://lccn.loc.gov/2019056811

© 2020 Quintessence Publishing Co, Inc

Quintessence Publishing Co, Inc
411 N Raddant Rd
Batavia, IL 60510
www.quintpub.com

5 4 3 2 1

All rights reserved. This book or any part thereof may not be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, or otherwise, without prior written permission of the publisher.

Editorial: Bryn Grisham & Samantha Smith
Design: Sue Zubek
Production: Sue Robinson

Printed in the United States

Contents

Foreword by David Gozal

Preface

In Memoriam

Contributors

Abbreviations

Section I  Introduction to Dental Sleep Medicine

1 The Nature and Structure of Sleep

Cibele Dal Fabbro, Monica L. Andersen, Gilles J. Lavigne

2 Sleep Neurobiology

Florin Amzica, Gilles J. Lavigne, Barry J. Sessle, Florian Chouchou

3 A Dental Perspective on the Classification of Sleep Disorders

Raphaël C. Heinzer, Peter A. Cistulli, Alberto Herrero Babiloni, Gilles J. Lavigne

4 Role of Dentists in Sleep Medicine

Gilles J. Lavigne, Raphaël C. Heinzer, Cibele Dal Fabbro, Michael T. Smith, Jean-François Masse, Fernanda R. Almeida, Takafumi Kato, Frank Lobbezoo, Peter A. Cistulli

Section II  Sleep Breathing Disorders

5 Overview of Guidelines/Protocols for SDB

Galit Almoznino, Rafael Benoliel, Frank Lobbezoo, Luc Gauthier

6 Sleep-Related Breathing Disorders

Joseph M. Duncan, Andrew S.L. Chan, Richard W.W. Lee, Peter A. Cistulli

7 Pathophysiology of OSA

Danny J. Eckert

8 Mouth Breathing, Dentofacial Morphology, and SDB

Stacey D. Quo, Benjamin Pliska, Nelly Huynh

9 Long-Term Consequences of OSA

Frédéric Gagnadoux

10 Periodontal Diseases and OSA

Maria Clotilde Carra, Joerg Eberhard, Peter A. Cistulli

11 Clinical Approaches to Diagnosis of Adult OSA

Anna M. Mohammadieh, Richard W.W. Lee, Andrew S.L. Chan

12 Imaging in OSA

Kate Sutherland, Richard J. Schwab, Lynne E. Bilston

13 An Overview of OSA Treatment in Adults

Jesse W. Mindel, Ryan Donald, Ulysses J. Magalang

14 Diagnosis and Management of Pediatric OSA

Dimple Goel, Dominic A. Fitzgerald

15 Orofacial Orthopedic Treatment

Stacey D. Quo, Benjamin Pliska, Nelly Huynh

16 Oral Appliance Therapy

Fernanda R. Almeida, Kate Sutherland, Peter A. Cistulli

17 Upper Airway Surgical Management of OSA

Leon Kitipornchai, Stuart G. MacKay

18 Emerging Therapies for OSA

Olivier M. Vanderveken

19 Risks of Anesthesia in Patients with OSA

David R. Hillman

20 Myofunctional Therapy for OSA

Wen-Yang Li, Jean-François Masse, Frédéric Sériès

21 Precision Medicine Approaches for OSA

Kate Sutherland, Peter A. Cistulli

22 Genetics of SDB

Sutapa Mukherjee, Lyle J. Palmer

Section III  Sleep Bruxism: From Oral Behavior to Disorder

23 Definitions, Epidemiology, and Etiology of SB

Frank Lobbezoo, Jari Ahlberg, Daniel A. Paesani, Ghizlane Aarab

24 Clinical Approaches to Diagnosis of SB

Kiyoshi Koyano, Yoshihiro Tsukiyama, Peter Wetselaar

25 SB as a Comorbid Condition of Other Sleep-related Disorders

Ghizlane Aarab, Ramesh Balasubramaniam, Milton Maluly Filho, Gilles J. Lavigne

26 Physiologic Mechanisms Associated with SB Genesis

Takafumi Kato, Kazuo Okura, Guido M. Macaluso, Gilles J. Lavigne

27 Psychosocial Factors in Sleep and Awake Bruxism and Other Oral Parafunctions

Richard Ohrbach, Sylvia D. Kreibig, Ambra Michelotti

28 Genetic and Environmental Factors in SB

Kazuyoshi Baba, Yuka Abe, Samar Khoury, Frank Lobbezoo

29 Consequences of SB on the Dentition, Dental Restorations, and Implants and How to Mitigate Them

Sandro Palla, Iven Klineberg, Mauro Farella

30 Behavioral, Dental, Pharmacologic, and Alternative Management of SB

Daniele Manfredini, Charles R. Carlson, Ephraim Winocur, Frank Lobbezoo

31 SB in Children and Adolescents

Nelly Huynh, Naomi Kadoch, Christian Guilleminault

Section IV  Sleep and Orofacial Pain

32 Definition and Classification of Orofacial Pains

Alberto Herrero Babiloni, Donald R. Nixdorf

33 Pathophysiologic Conceptualizations of the Transition from Acute to Chronic Pain

Claudia M. Campbell, Robert R. Edwards, Janelle E. Letzen

34 Mechanisms Underlying the Interactions Between Sleep Deficiency and Pain

Monika Haack, Navil Sethna

35 Behavioral and Pharmacologic Approaches to Manage Chronic Pain Comorbid with Sleep Disturbances

Monika Haack, Navil Sethna

36 Association and Putative Causality of Orofacial Pain Conditions and Sleep Disturbances

Peter Svensson, Lene Baad-Hansen, Taro Arima, Antoon De Laat

37 Sleep and Headache

Scott Maddalo, Shuja Rayaz, Michael T. Smith, Nauman Tariq

38 Pharmacologic Management of Sleep-Pain Interactions

Traci J. Speed

39 The Use and Risks of Opioids in the Management of Orofacial Pain

Alberto Herrero Babiloni, Léa Proulx-Bégin, Gilles J. Lavigne, Marc O. Martel

40 Nonpharmacologic Management of Insomnia and Orofacial Pain

Daniel Whibley, Nicole K.Y. Tang, Michael T. Smith

Index

Foreword

It is quite unbelievable that more than 10 years have elapsed since the first edition of Sleep Medicine for Dentists appeared! At that time, it seemed almost daring to publish a book on sleep disorders aimed at the dental profession. Yet, there is little doubt now that dentists are one of the many important portals of entry through which patients can gain earlier detection and therefore benefit from improved management of sleep disorders. Furthermore, the array of uniquely valuable and efficacious tools that dentists bring to the field is further enhanced by the fact that increased knowledge of sleep among any health care professional and by the public at large can only lead to better outcomes.

We cannot forget, or for that matter let anyone else forget, that sleep is a vital function and constitutes the fourth pillar of health and wellness. As such, rather than continue the isolationist route of silo building across professions and disciplines, focusing only on our area of expertise, there has been a slow and steady progressive evolution toward multidisciplinary and interdisciplinary cooperation in sleep medicine. Are we there yet? No, not yet, but we are moving in the right direction, and to continue getting there, we need to make sure that all health care professionals receive adequate and informative training focused around sleep and its disorders.

Before I comment on how this new edition of the book elegantly achieves such lofty goals, I want to remind ourselves that we tend to forget large portions of the wisdom generated by our predecessors. I was recently pointed to a paper published in 1913 by The Boston Medical and Surgical Journal (now The New England Journal of Medicine). In this short manuscript, Dr Irving Sobotky was already challenging the effectiveness of adenotonsillectomy in children and remarked on the high frequency of patients who continued to be mouth breathers despite “successful” surgeries.1 He further elaborated on the importance of nasal breathing. More than 100 years after this observation, we are still in pursuit of the elusive ideal of nasal breathing. Hopefully, this time, we can count on not only ENTs and sleep physicians but on the many other disciplines, and top among them, dentists, to help our patients breathe well through their noses.

As a sleep physician who has been deeply involved in sleep medicine over 30 years, I am thrilled to see the uniquely exquisite attention and effort paid in this new edition to facilitate learning and attract learners. The content is carefully divided and balanced between important areas of sleep that are pertinent to the dental profession, and the inordinately attractive and visually pleasing layout of text, tables, and graphics makes it nearly impossible to let go of the book once you get started. I would definitely hope that this textbook will become a mandatory part of the curriculum for all dental schools, and that it will stimulate many of its readers to not only put the knowledge gained to practice but also go and dig deeper and bring their ingenuity to the forefront, thereby advancing the field.

David Gozal, MD, MBA

Marie M. and Harry L. Smith Endowed Chair

Chairperson and Pediatrician-in-Chief

Department of Child Health

MU Women’s and Children’s Hospital

University of Missouri School of Medicine

Columbia, Missouri

1. Sobotky I. Persistent mouth breathing following adenoidectomies. Boston Med Surg J 1913;168:230–231.

Preface

It has been 11 years since the publication of the first edition of this dental sleep medicine book with Quintessence. The key aim of Sleep Medicine for Dentists was to provide a rapid source of practical information to students, practicing dentists, and scientists about the evolving field of dental sleep medicine. We sought to put a stake in the ground to herald the emergence of a new interdisciplinary field. The first edition was an instant success, with such strong continued interest that in the last few years the book has only been available for resale by a previous owner. This is a strong indication that the field of dental sleep medicine is growing in both the clinical practice and academic spheres. The book became an academic and board exam reference—a testament to its stature as an authoritative but concise resource. We thank everyone who believed in our collective work.

The role of dentistry in sleep medicine has evolved considerably over the last decade and is now accepted as an important component of the multidisciplinary approach to diagnosis and management of patients with diverse sleep complaints across the lifespan. There is a critical role for dentistry from childhood upper airway and oral development to management of adult sleep apnea, diagnosis of oral conditions linked to sleep-disordered breathing, sleep bruxism, and orofacial pain syndromes. What was previously considered the exclusive domain of the medical profession has now expanded to other disciplines, including dentistry, psychology, and physical/speech therapy. Dentists, dental therapists, and hygienists are among a team of collaborators that are increasingly and, sometimes uniquely, well-positioned in health care systems to maintain quality of life and optimal health for patients suffering with sleep-related breathing disorders, sleep bruxism, orofacial pain, and other orofacial-related syndromes that disrupt sleep and exacerbate pain and fatigue. The role of concomitant conditions (ie, comorbidities) with the above three major sleep problems is also of critical concern.

We believe the timing of this second edition is a perfect way to highlight the incredible advancements that have occurred in the last decade to entrench the role of dentistry in sleep medicine. The 2020 edition has been expanded from 24 to 40 chapters. As before, the book has 4 sections: Introduction to Dental Sleep Medicine, Sleep Breathing Disorders, Sleep Bruxism: From Oral Behavior to Disorder, and Sleep and Orofacial Pain. All previous chapters were updated, and new ones have been added based on the suggestions of many of our readers. The objective of this new edition is to present evidence-based material in a practical manner to guide students in their training and clinicians in their practice.

Editing such a book would have been impossible without the collective, respectful, and professional effort of the three editors, and our colleague Frank Lobbezoo, who provided invaluable input on the sleep bruxism section. We owe our gratitude to all authors and coauthors for their generosity of time, commitment, and integrity. They have come together to share with you the best of their knowledge and their passion for dental sleep medicine. We also want to thank Bryn Grisham and Samantha Smith from Quintessence for their perseverance in working on the second edition of the book.

In Memoriam

Christian Guilleminault (1938–2019)

This book is dedicated to Doctor Christian Guilleminault, who was a faithful advocate for the role and importance of dental sleep medicine.

Contributors

Ghizlane Aarab, DDS, PhD

Associate Professor

Department of Orofacial Pain and Dysfunction

Academic Centre for Dentistry Amsterdam (ACTA)

University of Amsterdam and Vrije Universiteit Amsterdam

Amsterdam, Netherlands

Yuka Abe, DDS, PhD

Assistant Professor

Department of Prosthodontics

Showa University

Tokyo, Japan

Jari Ahlberg, DDS, PhD

Associate Professor

Department of Oral and Maxillofacial Diseases

University of Helsinki

Helsinki, Finland

Fernanda R. Almeida, DDS, PhD

Associate Professor

Department of Oral Health Science

Faculty of Dentistry

University of British Columbia

Vancouver, British Columbia

Galit Almoznino, DMD, MSc, MHA

Senior Lecturer and Head

Big Biomedical Data Research Laboratory

Orofacial Sensory Clinic

Taste and Smell Clinic

Department of Oral Medicine Sedation & Maxillofacial Imaging

Hebrew University Hadassah School of Dental Medicine

Jerusalem, Israel

Florin Amzica, PhD

Professor

Departments of Stomatology and Neuroscience

Faculties of Dentistry and Medicine

Université de Montréal

Montréal, Québec

Monica L. Andersen, PhD

Associate Professor and Vice-Chair

Department of Psychobiology

Escola Paulista de Medicina

Universidade Federal de São Paulo

São Paulo, Brazil

Taro Arima, DDS, PhD

Associate Professor

Faculty of Dental Medicine

Hokkaido University

Sapporo, Japan

Lene Baad-Hansen, DDS, PhD, Dr Odont

Associate Professor and Deputy Department Head

Department of Dentistry and Oral Health

Aarhus University

Aarhus, Denmark

Kazuyoshi Baba, DDS, PhD

Professor and Chair

Department of Prosthodontics

Showa University

Director

Showa University Dental Hospital

Tokyo, Japan

Ramesh Balasubramaniam, BDSc, MS, MRACDS (OralMed), FOMAA

Clinical Associate Professor

Faculty of Health and Medical Sciences

University of Western Australia Dental School,

Perth, Australia

Rafael Benoliel, BDS, LDS, RCS

Professor and Associate Dean for Research

Director

Center for Orofacial Pain and TMDs

Rutgers School of Dental Medicine

State University of New Jersey

Newark, New Jersey

Lynne E. Bilston, PhD

Senior Principal Research Fellow

Neuroscience Research Australia

Conjoint Professor in Medicine

University of New South Wales

Sydney, Australia

Claudia M. Campbell, PhD

Associate Professor

Department of Psychiatry and Behavioral Sciences

Johns Hopkins University School of Medicine

Baltimore, Maryland

Charles R. Carlson, PhD

Professor

Department of Psychology and Oral Health Practice

University of Kentucky

Lexington, Kentucky

Maria Clotilde Carra, DDS, MSc, PhD

Associate Professor

Department of Periodontology

Rothschild Hospital

Paris, France

Faculty of Odontology

University of Paris

Paris, France

Andrew S. L. Chan, MBBS, PGCertClinLds, MBA, PhD, FRACP

Deputy Director

Centre for Sleep Health and Research

Department of Respiratory and Sleep Medicine

Royal North Shore Hospital

Clinical Associate Professor

The University of Sydney School of Medicine

Sydney, Australia

Florian Chouchou, PhD

Assistant Professor

Department of Physical Activity and Sports Science

University of La Réunion

La Réunion, France

Peter A. Cistulli, MD, PhD, MBA, FRACP, FCCP, ATSF

Professor

ResMed Chair in Sleep Medicine

Charles Perkins Centre

Faculty of Medicine and Health

University of Sydney

Director of the Centre for Sleep Health and Research

Department of Respiratory and Sleep Medicine

Royal North Shore Hospital

Sydney, Australia

Cibele Dal Fabbro, DDS, MSc, PhD

Clinician

Instituto do Sono

Visiting Research Scientist

Center for Advanced Research in Sleep Medicine

Sacred Heart Hospital of Montréal

Montréal, Québec

Antoon De Laat, DDs, PhD

Professor

Department of Oral Health Sciences

Catholic University of Leuven

Leuven, Belgium

Ryan Donald, MD

Assistant Professor

Division of Pulmonary, Critical Care, and Sleep Medicine

Department of Medicine

The Ohio State University Wexner Medical Center

Columbus, Ohio

Joseph M. Duncan, MBBS

Sleep Fellow

Department of Respiratory and Sleep Medicine

Royal North Shore Hospital

Sydney, Australia

Joerg Eberhard, Dr med dent, MME

Chair of Lifespan Oral Health

Charles Perkins Centre

University of Sydney School of Dentistry

University of Sydney

Sydney, Australia

Danny J. Eckert, PhD

Professor

College of Medicine and Public Health

Director

Adelaide Institute for Sleep Health

Flinders University

Bedford Park, Australia

Robert R. Edwards, PhD

Associate Professor of Anesthesia

Pain Management Center

Brigham and Women’s Hospital

Harvard Medical School

Boston, Massachusetts

Mauro Farella, DDS, PhD

Professor and Chair

Discipline of Orthodontics

Department of Oral Sciences

Sir John Walsh Research Institute

University of Otago

Dunedin, New Zealand

Milton Maluly Filho, DDS, PhD

Postdoctoral Fellow

Division of Sleep Medicine and Biology

Department of Psychobiology

Paulista School of Medicine

Federal University of São Paulo

São Paulo, Brazil

Dominic A. Fitzgerald, MBBS, PhD, FRACP

Pediatric Respiratory Sleep Physician and Professor

Discipline of Child & Adolescent Health

Department of Respiratory Medicine

The Children’s Hospital at Westmead

Sydney Medical School

University of Sydney

Sydney, Australia

Frédéric Gagnadoux, MD, PhD

Professor

Department of Respiratory and Sleep Medicine

Angers University Hospital

Angers, France

Luc Gauthier, DMD, MSc

Visiting Professor

Faculty of Dentistry

Université de Montréal

Montréal, Québec

Dimple Goel, MBBS, MD, FRACP

Pediatric Sleep Fellow

Department of Respiratory Medicine

The Children’s Hospital at Westmead

Conjoint Associate Lecturer

Pediatric and Child Health Division

University of Sydney

Sydney, Australia

Christian Guilleminault,* MD, DM, DBiol

Professor

Sleep Medicine Program

Department of Psychiatry and Behavioral Sciences

Stanford University School of Medicine

Redwood City, California

Monika Haack, MA, PhD

Associate Professor

Department of Neurology

Harvard Medical School

Beth Israel Deaconess Medical Center

Boston, MA

Raphaël C. Heinzer, MD-MPH

Associate Professor and Head

Center for Investigation and Research in Sleep

Lausanne University Hospital

Lausanne, Switzerland

*Deceased

Alberto Herrero Babiloni, DDS, MS

PhD Student

Center for Advanced Research in Sleep Medicine

Sacred Heart Hospital of Montréal

Université de Montréal

Division of Experimental Medicine

McGill University

Montréal, Québec

David R. Hillman, AM, MBBS, FANZCA, FRCP, FRACP (hon)

Clinical Professor and Senior Principal

Research Fellow

Department of Pulmonary Physiology and Sleep Medicine

Sir Charles Gairdner Hospital

Centre for Sleep Science

University of Western Australia

Perth, Australia

Nelly Huynh, PhD

Associate Professor

Faculty of Dentistry

CHU Sainte-Justine Research Center

Université de Montréal

Montréal, Québec

Naomi Kadoch, DMD

Research Student

Faculty of Dentistry

Université de Montréal

Montréal, Québec

Takafumi Kato, DDS, PhD

Professor

Department of Oral Physiology

Graduate School of Dentistry

United Graduate School of Child Development

Osaka University

Sleep Medicine Center

Osaka University Medical Hospital

Osaka, Japan

Samar Khoury, PhD

Postdoctoral Fellow

Alan Edwards Center for Research on Pain

McGill University

Montréal, Québec

Leon Kitipornchai, BEng, MBBS, MEpi, FRACS

Clinical Senior Lecturer

School of Clinical Medicine

University of Queensland

Brisbane, Australia

Iven Klineberg, AM, RFD, BSc, MDS, PhD, FDSRCS, FICD

Emeritus Professor of Prosthodontics

School of Dentistry

Faculty of Medicine and Health

Westmead Hospital Centre for Oral Health

University of Sydney

Sydney, Australia

Kiyoshi Koyano, DDS, PhD

Professor

Division of Oral Rehabilitation

Faculty of Dental Science

Kyushu University

Fukoka, Japan

Sylvia D. Kreibig, PhD

Senior Research Scientist

Department of Psychology

Stanford University

Stanford, California

Gilles J. Lavigne, DMD, PhD, FRCD(c), hc, FACD, FCAHS, OC (CM)

Professor

Canada Research Chair on Pain, Sleep, and Trauma

Faculty of Dental Medicine

Université de Montréal

Clinical Research Scientist

Center for Advanced Research in Sleep and Trauma Unit

Sacred Heart Hospital (CIUSSS North Island)

Montréal, Québec

Richard W. W. Lee, MBBS, PhD, FRACP

Codirector

Sleep Investigation Unit

Department of Respiratory Medicine

Gosford Hospital

Conjoint Senior Lecturer

School of Medicine and Public Health

University of Newcastle

New South Wales, Australia

Janelle E. Letzen, PhD

Postdoctoral Research Fellow

Department of Psychiatry and Behavioral Sciences

Johns Hopkins University School of Medicine

Baltimore, Maryland

Wen-Yang Li, MD, PhD

Lecturer

Respiratory and Critical Care Department

First Hospital of China Medical University

Shen Yang City, China

Frank Lobbezoo, DDS, PhD

Professor, Chair, and Vice-Dean

Department of Orofacial Pain and Dysfunction

Academic Centre for Dentistry Amsterdam (ACTA)

University of Amsterdam and Vrije Universiteit Amsterdam

Amsterdam, The Netherlands

Guido M. Macaluso, MD, DDS, MDS

Director

Center of Dental Medicine

Dean

Department of Medicine and Surgery

School of Dentistry

University of Parma

Parma, Italy

Stuart G. MacKay, BSc (Med), MBBS (Hons), FRACS

Honorary Clinical Professor

Otolaryngology and Head and Neck Surgery

University of Wollongong Graduate School of Medicine and Illawarra Shoalhaven Local Health District

Wollongong, Australia

Scott Maddalo, MD, MS

Pain Management Specialist

Department of Anesthesiology

St John’s Riverside Hospital

Hawthorne, New York

Ulysses J. Magalang, MD

Professor

Neuroscience Research Institute

Division of Pulmonary, Critical Care, and Sleep Medicine

Department of Medicine

The Ohio State University Wexner Medical Center

Columbus, Ohio

Daniele Manfredini, DDS, PhD

Professor

School of Dentistry

Department of Biomedical Technologies

University of Siena

Siena, Italy

Marc O. Martel, PhD

Assistant Professor

Faculty of Dentistry and Department of Anesthesia

McGill University

Montréal, Québec

Jean-François Masse, DMD, MSc

Visiting Professor

Faculty of Dentistry

Laval University

Québec City, Québec

Ambra Michelotti, BSc, DDS

Professor

Department of Neurosciences, Reproductive Sciences and Oral Sciences

Division of Orthodontics

University of Naples Federico II

Naples, Italy

Jesse W. Mindel, MD

Assistant Professor of Neurology and Internal Medicine

Department of Neurology

Department of Medicine

Division of Pulmonary, Critical Care, and Sleep Medicine

The Ohio State University Wexner Medical Center

Columbus, Ohio

Anna M. Mohammadieh, BA, MBBS, FRACP

Respiratory and Sleep Physician

Centre for Sleep Health and Research

Department of Respiratory Medicine

Royal North Shore Hospital

Charles Perkins Centre

University of Sydney

Sydney, Australia

Department of Thoracic Medicine

St Vincent’s Hospital

Darlinghurst, Australia

Sutapa Mukherjee, MBBS, PhD

Associate Professor

Sleep Health Service

Respiratory and Sleep Services

Southern Adelaide Local Health Network

Adelaide Institute for Sleep Health

Flinders University

Adelaide, Australia

Donald R. Nixdorf, DDS, MS

Professor and Director

Division of TMD/Orofacial Pain

School of Dentistry

University of Minnesota

Minneapolis, Minnesota

Department of Neurology

Medical School

University of Minnesota

Minneapolis, Minnesota

Richard Ohrbach, DDS, PhD

Professor

Department of Oral Diagnostic Sciences

University at Buffalo School of Dental Medicine

Buffalo, New York

Kazuo Okura, DDS, PhD

Lecturer

Department of Stomatognathic Function and Occlusal Reconstruction

Institute of Biomedical Sciences

Tokushima University Graduate School

Tokushima, Japan

Daniel A. Paesani, DDS

Professor of Stomathognatic Physiology

University of Salvador

Buenos Aires, Argentina

Sandro Palla, Dr med dent

Emeritus Professor

Center for Dentistry

University of Zürich

Zürich, Switzerland

Lyle J. Palmer, PhD

Professor of Genetic Epidemiology

School of Public Health

University of Adelaide

Adelaide, Australia

Benjamin Pliska, DDS, MS

Associate Professor

Division of Orthodontics

Faculty of Dentistry

University of British Columbia

Vancouver, British Columbia

Léa Proulx-Bégin, BA

Doctoral Candidate

Department of Psychology

Université de Montréal

Montréal, Québec

Stacey D. Quo, DDS, MS

Clinical Professor

Department of Orofacial Sciences

School of Dentistry

University of California

San Francisco, California

Shuja Rayaz, MD

Resident

Department of Medicine

Mercy Hospital

Baltimore, Maryland

Richard J. Schwab, MD

Professor

Center for Sleep and Circadian Neurobiology

Perelman School of Medicine

University of Pennsylvania Medical Center

Philadelphia, Pennsylvania

Frédéric Sériès, MD

Professor

Centre de pneumologie

Québec Cardiology and Respirology University Institute

Laval University

Québec City, Québec

Barry J. Sessle, MDS, PhD, FRSC

Professor

Faculty of Dentistry and Medicine

Department of Physiology

University of Toronto

Toronto, Ontario

Navil Sethna, MBchB

Clinical Director of the Pediatric Pain Rehabilitation Center

Senior Associate in Perioperative Anesthesia

Department of Anesthesiology, Critical Care, and Pain Medicine

Boston Children’s Hospital

Boston, Massachusetts

Associate Professor in Anesthesiology

Harvard Medical School

Cambridge, Massachusetts

Michael T. Smith, PhD, DBSM

Professor of Psychiatry and Behavioral Sciences

Professor of Neurology

Director, Division of Behavioral Medicine

Johns Hopkins University School of Medicine

Baltimore, Maryland

Traci J. Speed, MD, PhD

Assistant Professor

Department of Psychiatry and Behavioral Sciences

Johns Hopkins University School of Medicine

Baltimore, MD

Kate Sutherland, PhD

Research Fellow

Sleep Group

Charles Perkins Centre

Faculty of Medicine and Health

University of Sydney School of Medicine

Centre for Sleep Health and Research

Department of Respiratory Medicine

Royal North Shore Hospital

Sydney, Australia

Peter Svensson, DDS, PhD, DrOdont

Professor and Head

Section of Orofacial Pain and Jaw Function

Department of Dentistry and Oral Health

Faculty of Health

Aarhus University

Aarhus, Denmark

Nicole K.Y. Tang, DPhil CPsychol

Reader

Department of Psychology

University of Warwick

Coventry, United Kingdom

Nauman Tariq, MBBS

Assistant Professor of Neurology

Director, Headache Center

Johns Hopkins School of Medicine

Baltimore, MD

Yoshihiro Tsukiyama, DDS, PhD

Professor

Section of Dental Education

Division of Oral Biological Sciences

Faculty of Dental Science

Kyushu University

Fukuoka, Japan

Olivier M. Vanderveken, MD, PhD

Professor and Chairman of Ear, Nose, Throat, Head, and Neck Surgery Deparment

Antwerp University Hospital

University of Antwerp

Antwerp, Belgium

Peter Wetselaar, DDS, MSc, PhD

Associate Professor

Department of Oral Kinesiology

Head

Clinic of Orofacial Pain and Dysfunction

Program Director

Oral Health Sciences

Academic Centre for Dentistry Amsterdam (ACTA)

University of Amsterdam and Vrije Universiteit Amsterdam

Amsterdam, The Netherlands

Daniel Whibley, PhD

Epidemiology Group

School of Medicine. Medical Sciences, and Nutrition

University of Aberdeen,

Aberdeen, United Kingdom

Ephraim Winocur, DMD

Clinical Assistant Professor

Department of Oral Rehabilitation

The Maurice and Gabriela Goldschleger School of Dental Medicine

Sackler Faculty of Medicine

Tel Aviv University

Tel Aviv, Israel

Abbreviations

This reference list contains the most common abbreviations used throughout the book. Please note that these terms will not be spelled out in the book.

CHAPTER 1

The Nature and Structure of Sleep

Cibele Dal Fabbro
Monica L. Andersen
Gilles J. Lavigne

In the animal kingdom, sleep is a universal and imperative biologic process to maintain and restore health. Sleep is defined as a physiologic and behavioral state characterized by partial isolation from the environment. A baby’s cry, the vibration of an earthquake, or a sudden pain intrusion will all interrupt sleep continuity; a sleeping brain maintains a sentinel function to awaken the organism for protection purposes.

The duration of sleep usually is 6 to 9 hours in adults. Although most adults sleep an average of 7.5 hours, some are short sleepers and some are long sleepers (ie, less than 5.5 hours and more than 9.0 hours, respectively). Good sleep quality is usually associated with a sense of having slept continuously through the night and feeling refreshed and alert on awakening in the morning. The perception of sleep quality is subjective and varies widely among individuals. Some individuals perceive their sleep as satisfying most of the time, and some consistently report being poor sleepers (eg, having difficulties in initiating or maintaining sleep—insomnia, feeling unrefreshed when they awaken, and having nightmares). However, sleep recording systems indicate that, in general, poor sleepers tend to underestimate the length of time they sleep (as do some good sleepers). The neurobiology of sleep is described in chapter 2, and a classification of the various sleep disorders relevant to dentistry is found in chapter 3.

Sleep-Wake Cycle

An adult’s 24-hour cycle is divided into approximately 16 hours of wakefulness and 8 hours of sleep. Synchronization and equilibrium between the sleep-wake cycle and feeding behaviors are essential for survival. Mismatches in the synchronization of the feeding cue and metabolic activity are associated with eating disorders.1 Poor sleep can cause health problems and can increase the risk of transportation- and work-related accidents and even death.2

Homeostatic process

The propensity to sleep is directly dependent on the duration of the prior wakefulness episode. As the duration of wakefulness increases, sleep pressure accumulates and builds to a critical point, when sleep onset is reached. As this sleep pressure increases, an alerting circadian signal helps the person to remain awake throughout the day. The ongoing 24-hour circadian rhythm therefore runs parallel to the homeostasis process, also known as process S (Fig 1-1). The process S corresponds to the sleep pressure that individuals accumulate during the wakefulness period before being able to fall asleep. With increasing sleep pressure, sleep is proportionally longer and deeper in the following recovery period.

Changes in the frequency of slow-wave sleep waves can be estimated by a mathematic transformation of brain wave electrical signals or by quantitative spectral analysis of the electroencephalographic (EEG) activity. Rising or rebound of slow-wave EEG activity in the first hours of sleep is a marker of sleep debt.3 In contrast, a reduction in slow-wave activity is observed in patients with chronic pain.4,5 However, the cause-and-effect association of these biologic signals with reports of fatigue and poor sleep is unknown. During the day, the effects of energy expenditure are accumulated, which may be connected to the feeling of tiredness.

Two times in the 24-hour cycle are characterized by a strong sleep pressure, 4 PM and 4 AM, +/- 1 to 2 hours (see Fig 1-1). At a certain point, sleep pressure is so powerful that an individual will fall asleep regardless of the method or strategies used to remain awake.

Circadian rhythm

Humans tend to alternate between a period of wakefulness lasting approximately 16 hours and a continuous block of 8 hours of sleep (see Fig 1-1). Most mammals sleep around a 24-hour cycle that is driven by clock genes that control the circadian rhythm (process C). Light helps humans synchronize their rhythm with the cycles of the sun and moon by sending a retinal signal (melanopsin) to the hypothalamic suprachiasmatic nucleus. The suprachiasmatic nucleus is a network of brain cells and genes that acts as a pacemaker to control the circadian timing function.6

The investigation of sleep-wake process C uses biologic markers to assess a given individual’s rhythm. A slight drop (hundredths of a degree centigrade) in body temperature and a rise in salivary and blood melatonin and growth hormone release—peaking in the first hours of sleep, around midnight in the 24-hour cycle—are key indications of the acrophase (high peak) of the process C. Interestingly, corticotropins (adrenocorticotropic hormone and cortisol) reach a nadir (lowest level) during the first hour of sleep. They then reach an acrophase in the second half of the night.1,7 The process C can also be studied using temperature recordings in relation to hormone release and polygraphy to measure brain, muscle, and heart activities.

Ultradian rhythm

Under the 24-hour process C of sleep and wakefulness, sleep onset and maintenance are governed by an ultradian cycle of three to five periods in which the brain, muscles, and autonomic cardiac and respiratory activities fluctuate (Figs 1-2 and 1-3).8 These cycles consist of REM sleep (active stage) and NREM sleep (light and deep stages). The REM stage is known as paradoxical sleep in some countries.

In humans, a clear decline in electrical brain and muscle activities as well as heart rhythm is observed from wakefulness to sleep onset. This decline is associated with a synchronization of brain waves toward stage N1 of sleep. Stage N1 is a transitional period between wakefulness and sleep. Stage N2, which accounts for about 50% to 60% of total sleep duration, is characterized by two EEG signals—K-complexes (brief, high-amplitude brain waves) and spindles (rapid, spring-like EEG waves)—both described as sleep-promoting and sleep-preserving factors. Sleep N1 and N2 are categorized as light sleep.

Next, sleep enters a quiet period known as deep sleep, or stage N3, which is characterized by slow, high-amplitude brain wave activities, with dominance of delta sleep (0.5 to 4.5 Hz). This sleep period is associated with a so-called sleep recovery process.

Finally, sleep enters an ascension period and rapidly turns into either light sleep or REM sleep. REM sleep is associated with a reduction in the tone of postural muscles (which is poorly described as “atonia” in literature but is in fact hypotonia because muscle tone is never zero; see chapter 2, reference 13) and a rise in heart rate and brain activity to levels that frequently surpass the rates observed during wakefulness.

Humans can dream in all stages of sleep, but dreams during REM sleep may involve intensely vivid imagery with fantastic and creative content. During REM sleep, the body is typically in a paralyzed-like state (muscle hypotonia). Otherwise, dreams with intense emotional content and motor activity might cause body movements that could injure individuals and their sleep partners.

An understanding of the presence of ultradian sleep cycles is relevant because certain pathologic events occur during sleep, including the following sleep disorders:

• Periodic body movements (leg or arm) and jaw movements, such as SB, most of which are observed in stage N2 of sleep and with less frequency in REM sleep

• Sleep-related breathing events, such as apnea and hypopnea (cessation or reduction of breathing), observed in N2 and REM sleep

• Acted dreams with risk of body injury, diagnosed as RBD, which occur during REM sleep (see chapter 3)

Sleep Recordings and Sleep Arousal

When a PSG of a sleeping patient (collected either at home with an ambulatory system or in a sleep laboratory) is assessed, the scoring of sleep fragmentation is a key element in analyzing sleep quality. Poor sleep quality, as reported subjectively by the patient, is associated on PSGs with more bed time with wake after sleep onset (WASO), frequent arousals with or without body movements or with a high score of periodic limb movement (PLM), frequent stage shifts (from a deeper to a lighter sleep stage), respiratory disturbances (measured per hour by the respiratory disturbance index [RDI]), and higher muscle tone. All these signs of sleep fragmentation interrupt the continuity of sleep and alter the sleep architecture.

Sleep efficiency is another important variable to evaluate. A standard index of sleep impairment, sleep efficiency is defined as the amount of time asleep divided by the amount of time spent in bed, expressed as a percentage. Sleep efficiency greater than 90% is an indicator of good sleep.

The ultradian cycle of sleep, described previously, includes another repetitive activity: sleep-related arousals. During NREM sleep, arousals are recurrent (6 to 14 times per hour of sleep), involving brief (3 to 10 seconds) awakenings associated with increased brain, muscle, and heart activities (tachycardia or rapid heart rate) in the absence of the return of consciousness.9–11 In the presence of sleep movements, breathing disorders, or chronic pain, these arousals are more frequent. Sleep arousals can be viewed as the body’s attempt to prepare the sleeping individual (who is in a low-vigilance state) to react to a potential risk, ie, a fight-or-flight state.

Sleep arousals are concomitant with or precede most PLMs and SB (described also in chapter 26 on pathophysiology of SB, section III). In contrast, sleep apnea and hypopnea (described in section II) are respiratory distress–like events that trigger sleep arousals. An index of arousal per hour of sleep is estimated as well as arousal-related ones: frequency of shifts in sleep stage, PLMs, bruxism, snoring, and sleep-related apnea and hypopnea.

In addition to these methods, sleep fragmentation can be estimated by the presence of the cyclic alternating pattern (CAP) to evaluate the instability of sleep. CAP is an infraslow oscillation, with a periodicity of 20 to 40 seconds, between the sleep maintenance system and the arousal pressure involved in the dynamic organization of NREM sleep and the activation of motor events.12

CAP is the estimate of the dominance of active phasic arousal periods—that is, the rise in heart rate, muscle tone, and EEG activities (phase A)—over more stable and quiet sleep periods (phase B).11,13 The active phase is subclassified as A1, a period that promotes sleep onset and maintenance; A2, a transition phase; and A3, the final phase, or the arousal window, involving a marked increase in muscle tone and cardiorespiratory rate. Note that most SB events are scored in phases A2 and A3 (see chapter 26).

People appear to have individual levels of tolerance for sleep fragmentation. These levels may be genetically determined. Nevertheless, recurrent sleep deprivation or fragmentation produces a cumulative sleep debt, which in turn is likely to increase complaints of fatigue, memory and mood dysfunction, and bodily pain. The cause-and-effect relationship remains to be supported by evidence.

Developmental Changes in Sleep-Wake Patterns

The human sleep-wake pattern changes with biologic maturation and aging. In the first 6 weeks of life, sleep of infants is dominated by REM sleep, which occupies about 50% of their sleep time. Around age 6 to 9 months, their wakefulness and nighttime sleep pattern tends to become more synchronized with their parents’ feeding and sleeping schedule.14 Preschool children sleep about 14 hours per 24-hour cycle, and most stop napping somewhere between the ages of 3 and 5 years. An important aspect related to development is the growth of the airway and involution of adenoids that seems to influence occurrence and resolution of snoring and apnea in children between 5 to 12 years of age (see chapter 14).

Pre-adolescent children are sleep-wake phase advanced. They fall asleep earlier and awake earlier than middle-aged adults. Teenagers tend to be phase delayed (get to bed later and wake later in morning) and tend to sleep about 9 hours per 24 hours (ranging from 6.5 to 9.5 hours), falling asleep and awakening later than their parents and younger siblings.

Most adults sleep about 6 to 7 hours on workdays and more on the weekends. By about the age of 40 to 45 years, adults’ sleep starts to become more fragile, and individuals are more aware of being awake for a few seconds to a few minutes a night. In the elderly, the sleep-wake pattern returns to a multiphase pattern typical of young children. Elderly people go to sleep earlier than middle-aged adults and awake earlier in the morning, taking occasional naps (catnapping) during the day. Some may present advanced phase shift, ie, get to sleep earlier and wake earlier in morning.

The human biologic clock can adapt to sleep deprivation and changes in the sleep-wake schedule within certain limits. For example, some people can adapt better than others to jetlag or sleep deprivation because of night work (eg, flight crew, hospital staff), but most individuals find such variations difficult.

Sleep and Health

The diagnosis, prevention, and management of sleep disorders are currently domains of high impact in public health (eg, prevention of breathing disorders from childhood, management of daytime sleepiness to decrease the risk of transportation accidents, and the relationship of hypertension and sleep apnea).

Sleep and circadian rhythm entail several functions, including physical recovery, biochemical refreshment (eg, synaptic neuronal function; glial cell role in glymphatic process), memory consolidation, emotional regulation, and to a small extent, possible learning of simple tasks/behaviors15–22 (Box 1-1). A persistent reduction in sleep duration can cause physical and mental health problems because of the cumulative effect of lack of sleep on several physiologic functions (see chapters 9 and 33 to 35).