TEMPOROMANDIBULAR
DISORDERS

Priorities for Research and Care

Enriqueta C. Bond, Sean Mackey, Rebecca English,
Cathy T. Liverman, and Olivia Yost, Editors

Committee on Temporomandibular Disorders (TMDs):
From Research Discoveries to Clinical Treatment

Board on Health Sciences Policy

Board on Health Care Services

Health and Medicine Division

A Consensus Study Report of

THE NATIONAL ACADEMIES PRESS
Washington, DC
www.nap.edu

THE NATIONAL ACADEMIES PRESS 500 Fifth Street, NW Washington, DC 20001

This activity was supported by a contract between the National Academy of Sciences and the U.S. Department of Health and Human Services: National Institutes of Health (NIH) (Office of the NIH Director and the National Institute of Dental and Craniofacial Research). Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of any organization or agency that provided support for the project.

International Standard Book Number-13: 978-0-309-67048-7
International Standard Book Number-10: 0-309-67048-9
Digital Object Identifier: https://doi.org/10.17226/25652
Library of Congress Control Number: 2020934005

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Suggested citation: National Academies of Sciences, Engineering, and Medicine. 2020. Temporomandibular disorders: Priorities for research and care. Washington, DC: The National Academies Press. https://doi.org/10.17226/25652.

COMMITTEE ON TEMPOROMANDIBULAR DISORDERS (TMDs): FROM RESEARCH DISCOVERIES TO CLINICAL TREATMENT

ENRIQUETA C. BOND (Chair), President Emeritus, Burroughs Wellcome Fund, QE Philanthropic Advisors

SEAN MACKEY (Vice Chair), Chief, Division of Pain Medicine, Stanford University Medical Center

PENNEY COWAN, Founder and Chief Executive Officer, American Chronic Pain Association

DAVID DEITZ, Principal, David Deitz & Associates, LLC FRANCESCA C. DWAMENA, Professor of Medicine, Michigan State University

ROGER B. FILLINGIM, Distinguished Professor, University of Florida

MARGARET M. HEITKEMPER, Professor and Chair, Biobehavioral Nursing & Health Systems, University of Washington

FRANCIS KEEFE, Professor of Psychiatry and Behavioral Sciences, Duke University Medical Center

KATE LORIG, Professor Emerita, Stanford University School of Medicine

RICHARD OHRBACH, Professor, Department of Oral Diagnostic Sciences, University at Buffalo School of Dental Medicine

AMANDA C. PUSTILNIK, Professor of Law, University of Maryland Carey School of Law

SRINIVASA N. RAJA, Professor of Anesthesiology and Critical Care, Medicine and Neurology, Johns Hopkins University School of Medicine

CORY M. RESNICK, Assistant Professor of Oral and Maxillofacial Surgery, Harvard School of Dental Medicine

ANTONY ROSEN, Vice Dean for Research, Mary Betty Stevens Professor of Medicine, Johns Hopkins University School of Medicine

KATHLEEN A. SLUKA, Kate Daum Research Professor, Department of Physical Therapy and Rehabilitation Science, University of Iowa Carver College of Medicine

BARBARA G. VICKREY, Professor and System Chair, Neurology Department, Icahn School of Medicine at Mount Sinai

ROBERT WEYANT, Professor, University of Pittsburgh School of Dental Medicine

HAI YAO, Ernest R. Norville Endowed Chair and Professor of Bioengineering and Craniofacial Biology, Clemson University and Medical University of South Carolina

Study Staff

CATHY T. LIVERMAN, Study Director

REBECCA ENGLISH, Study Director

OLIVIA YOST, Associate Program Officer

SIOBHAN ADDIE, Program Officer

KENDALL LOGAN, Senior Program Assistant

ANDREW M. POPE, Senior Director, Board on Health Sciences Policy

SHARYL NASS, Director, Board on Health Care Services

Consultants

JUSTIN DURHAM, School of Dental Sciences, Newcastle University

ERIN HAMMERS FORSTAG, Common Good Consulting

GARY SLADE, University of North Carolina School of Dentistry

Reviewers

This Consensus Study Report was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in making each published report as sound as possible and to ensure that it meets the institutional standards for quality, objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process.

We thank the following individuals for their review of this report:

Although the reviewers listed above provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations of this report nor did they see the final draft before its release. The review of this report was overseen by DAN G. BLAZER II, Duke University School of Medicine, and MICHELLE M. MELLO, Stanford Law School and Stanford University School of Medicine. They were responsible for making certain that an independent examination of this report was carried out in accordance with the standards of the National Academies and that all review comments were carefully considered. Responsibility for the final content rests entirely with the authoring committee and the National Academies.

Contents

PREFACE

SUMMARY

1 INTRODUCTION

Complexity of TMDs

Challenges in Care: Patient Experiences

Identifying the Appropriate Model for TMD Care and Research

Key Themes

Organization of This Report

References

2 DEFINITIONS AND SCOPE: WHAT ARE TMDs?

Terminology: What Term Should Be Used for This Set of Disorders?

Diagnostic Criteria to Categorize Types of TMDs

Types of TMDs

Understanding the Etiologies of TMDs

Factors in the Disease Course of a TMD

What Can Be Learned from Other Pain Conditions?

What Can Be Learned from Other Orthopedic Conditions?

Conclusions and Research Priorities

References

3 INDIVIDUAL AND SOCIETAL BURDEN OF TMDs

Prevalence of TMDs

Incidence of TMDs

Burden and Costs of TMDs

Comorbidities

Risk Factors for TMDs

Conclusions and Research Priorities

References

4 STATE OF THE SCIENCE ON TMDs

Recent Biomechanical and Bioengineering Research on the TMJ

Neurobiology of Orofacial Pain and TMDs

Neuroimmune Interactions and TMDs

Neuroendocrine Interactions, Stress Response, and TMDs

Biomarkers and Molecular Genetics of TMDs

Neuroimaging of the Central Nervous System: Exploration of TMD Phenotypes

Psychosocial Factors Underlying TMDs

Application of Data Science Methodologies and Novel Technologies to TMD Research

TMD Research Funding

Moving the Research Enterprise Forward

A National Collaborative Research Consortium and Framework for Action

Conclusions

References

5 CARING FOR INDIVIDUALS WITH A TMD

First, Do No Harm

Prevention and Early Detection

Assessment and Diagnosis of TMDs

TMD Treatments

Improving and Disseminating Evidence

Conclusions

References

6 IMPROVING TMD HEALTH CARE: PRACTICE, EDUCATION, ACCESS, AND COVERAGE

TMD Health Care Pathways

Improving Interprofessional Education and Collaboration

Strengthening Education and Training

Improving Access to Specialty Care

Improving Payment and Coverage

Conclusions and Research Priorities

References

7 IMPROVING PATIENT, FAMILY, AND PUBLIC EDUCATION AND AWARENESS ABOUT TMDs

Overcoming Stigma

Increasing Patient and Family Education and Improving Communication with Health Care Professionals

Raising Public Awareness and Knowledge About TMDs

Conclusion and Research Priorities

References

8 NEXT STEPS AND RECOMMENDATIONS

Build and Sustain Collaborative and Multidisciplinary Research

Improve Access to and Quality of TMD Health Care

Improve Health Care Professional Education About TMDs

Raise Awareness, Improve Education, and Reduce Stigma

Opportunities for Action

References

APPENDIXES

A Workshop and Open Session Agendas

B Committee Biographical Sketches

C Commissioned Paper by Gary Slade and Justin Durham

D Masticatory System: Anatomy and Function

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Preface

Everyday activities, including eating and talking, are often difficult for people with temporomandibular disorders (TMDs), and many of them suffer severe chronic pain due to this condition. Common social activities that most people take for granted, such as smiling, laughing, and kissing, can become unbearable. This dysfunction and pain, and its associated suffering, take a terrible toll on affected individuals, their families, and their friends. Individuals with TMDs often feel stigmatized and invalidated in their experiences by their family, friends, and, particularly, a health care community that frequently relies on “seeing” a condition in order to treat it. Misjudgments and a failure to understand the nature and depths of TMDs can have severe consequences—more pain and more suffering—for individuals, their families, and our society. People with TMDs, desperate for solutions, often seek out multiple clinicians, turning to dubious treatments in search of a cure, which can potentially lead to iatrogenic injury and costly, yet ineffective, treatments.

This study—focused on improving TMD care and identifying research directions—occurs at a time of both challenges and opportunities for progress in this field. TMDs are especially challenging because they often require care across medicine, dentistry, and other fields of health, and yet, given the current divide between the medical and dental fields in the United States, such coordinated care rarely happens. The medical–dental divide is further exacerbated by a payment system that inadequately reimburses for the complex care needed by people with TMDs. Clinicians can be affected by bias, limitations in their knowledge and training, and differences in the systems in which different types of clinicians work. Efforts are needed to

break down these silos and devote research efforts aimed at understanding this complex set of disorders and improving patient care. Furthermore, research is needed to learn more about the structure and function of the temporomandibular joint and the management of its associated disorders. Many TMDs do not exist in isolation, but rather are frequently associated with other painful conditions such as headache, neck and back pain, irritable bowel syndrome, fibromyalgia, sleep disorders, and chronic fatigue syndrome. Despite these challenges, a number of opportunities exist, such as in increasing patient involvement in order to help move health care forward and in new research tools and technologies that can expand the current understanding of the etiology and progression of TMDs. In responding to the study’s broad task—which stretches from research to education to care—this report aims to provide an overview of the current state of knowledge on TMDs and to focus its recommendations on near- and long-term actions to move the field forward in such a way that it improves care for individuals with a TMD as rapidly as possible.

The committee’s work greatly benefited from the compelling insights that were so graciously shared by many individuals with TMDs and their family members. These individuals described their often arduous and costly experiences in living with these often complex conditions, including the challenges of trying to navigate through fragmented and divided dental and medical health care systems and frequently dealing with health professionals who were largely unfamiliar with TMDs. We are grateful to these people for sharing their stories, hopes, disappointment, and anger in their written comments and testimonials. We kept those shared messages at the forefront of our deliberations and focus while creating this report.

The committee also greatly appreciates the information provided by workshop speakers as well as by many others who shared information with the committee. The feedback from the report reviewers was invaluable. We especially thank the study sponsors for their work on TMDs and for their support of this study: the Office of the Director at the National Institutes of Health and the National Institute of Dental and Craniofacial Research.

It was our great privilege to work with such dedicated committee members, each of whom thoroughly engaged in the study, generously shared their expertise, and contributed significant time and effort to this endeavor. This was a complex task, and the committee members stepped up to meet the challenge. Their reasoned and thoughtful discussions made this report possible. We were all fortunate to work with a diligent and outstanding team of National Academies of Sciences, Engineering, and Medicine staff, and we deeply thank Cathy Liverman, Rebecca English, Olivia Yost, Kendall Logan, and Siobhan Addie, led by Andrew Pope and Sharyl Nass, board directors in the Health and Medicine Division. We also thank Erin Hammers Forstag for her writing and editing work and Daniel Bearss of

the National Academies library staff for his assistance conducting detailed literature searches for the committee and staff.

The committee worked to develop this report in an objective manner based on the available evidence and knowledge. During this process we were acutely aware of the limitations in existing evidence and the data to support that evidence. These limitations and the opportunities to transform our understanding of TMDs helped guide our recommendations. TMDs result from a complex interplay between biological, biomechanical, psychological, and social factors that transcend simple explanations. Efforts are needed to enhance our understanding of TMDs from cells to society, taking advantage of team science approaches to these complex problems. Further progress will be made through the development and use of new tools, metrics, and biomarkers to diagnose TMDs and forecast their trajectory, predict treatment efficacy, and monitor advances in improving health and well-being. The education and training of health care professionals about TMDs and incentivizing them to work individually and in teams will be critical for making improvements in providing care of individuals with recent onset TMDs, chronic TMDs, or high-impact TMDs. Enhanced models of care will incentivize health care professionals to provide the most optimal care for people with TMDs—and do so in a way that is culturally sensitive and patient-centric. It is the committee’s hope that this report will provide a springboard to move this field forward.

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