Consider the joints of the human body. What might first come to mind are the hips and knees—the large joints that support us in our mobility—followed by the wrists, ankles, elbows, fingers, and toes. What can be overlooked, although clearly evident in the mirror, is one of the most used, most necessary, and perhaps most misunderstood set of joints—those of the jaw—which are critical to the vital work of human life, including eating, talking, kissing, and even breathing.
This report focuses on temporomandibular disorders (TMDs), a set of more than 30 health disorders associated with both the temporomandibular joints (TMJs) and the muscles and tissues of the jaw. TMDs have a range of causes and often co-occur with a number of overlapping medical conditions, including headaches, fibromyalgia, back pain, and irritable bowel syndrome. TMDs can be transient or long lasting and may be associated with problems that range from an occasional click of the jaw to severe chronic pain involving the entire orofacial region.
The national prevalence of TMDs is difficult to estimate due to challenges in conducting clinical examinations on a large scale, such that most prevalence data are based on self-reported symptoms associated with TMDs rather than examiner-verified classification. For example, one analysis of 2018 data found that an estimated 4.8 percent of U.S. adults (an estimated 11.2 to 12.4 million U.S. adults in 2018) had pain in the region of the TMJ that could be related to TMDs (see Chapter 3). Orofacial pain symptoms may or may not be related to TMDs. As discussed throughout this report, TMDs are a set of diverse and multifactorial conditions that can occur at
different stages in an individual’s life with a range of manifestations and impacts on quality of life.
Action is urgently needed to improve care for individuals with a TMD. Too long compartmentalized as a dental issue, both the clinical management of and research addressing TMDs need to implement a holistic and multidisciplinary approach. Individuals with TMD symptoms often encounter health professionals (across medicine, dentistry, and beyond) that are unfamiliar with TMDs and do not know where best to refer patients for further diagnosis and treatment. The divide between medical and dental care is currently vast in the United States and much of the world, and is a divide that profoundly affects care systems, payment mechanisms, and professional education and training.
This report explores a broad range of issues relevant to improving the health and well-being of individuals with a TMD. To address the study’s Statement of Task (see Chapter 1), the National Academies of Sciences, Engineering, and Medicine appointed an 18-member committee with expertise in public health; pain medicine; basic, translational, and clinical research; patient advocacy; physical therapy; dentistry; self-management; TMDs and orofacial pain; oral and maxillofacial surgery; health care services; internal medicine; endocrinology; rheumatology; law; nursing; psychiatry; and communications. The study was sponsored by the Office of the Director of the National Institutes of Health and the National Institute of Dental and Craniofacial Research.
CHALLENGES IN CARE: PATIENT EXPERIENCES
The committee greatly benefited from the input of individuals with a TMD and family members, many of whom face significant day-to-day challenges in living with a TMD. These challenges include difficulties in eating, in personal and social interactions, and in talking, which are often accompanied by severe ongoing pain. The committee received input from more than 110 individuals through in-person and online opportunities to testify at the committee’s public workshop (see Appendix A) and through written submissions to the study’s public access file.1 Among the many issues raised in these testimonies, several focused on the health care system and the care of individuals with a TMD:
- Lack of coordinated care and abandonment—Individuals reported that they were often shuffled back and forth between clinicians in the medical and dental fields with little to no attention paid to
a comprehensive approach to coordinated care. Patients also reported being abandoned by their dentists and other clinicians when the treatments did not work, with no referrals or other options provided.
- Over-treatment/harmful treatment—Many patients reported on having endured multiple TMD-related surgeries (in some cases more than 20), often with no resolution to their pain or with worsening symptoms. Other individuals reported that they had not had surgery but had had a removable oral appliance, orthodontic correction of the teeth, replacement of teeth, or some combination of these treatments.
- Impact on quality of life—Individuals with a TMD described how having a TMD has profound impacts on the quality of their day-today lives, from struggling in pain to kiss a loved one to challenges in dining out with friends or simply eating solid foods. Some individuals noted that the disorder affected their ability to work and to care for their families. Many described challenges in dealing with the emotional consequences of their condition and its treatment and with the episodic or ongoing pain that they experience.
- Expense—The financial burden of seeking and receiving care for a TMD was noted by individuals and family members. Some people said that they had received limited insurance coverage, but, for the most part, the coverage was paid out of pocket by the individual at costs of up to tens of thousands of dollars.
- Identifying qualified health care professionals—Individuals with a TMD and their families often expressed their frustration at not knowing where to turn for quality care. Primary care and internal medicine clinicians and general dentists often did not know how to help them locate qualified specialists. Patients were highly aware of the TMJ implant failures of the 1970s and 1980s and conveyed their concerns about the lack of quality treatment options for TMDs. Additionally, they noted that misleading advertising practices—in which clinicians claim to be experts but do not have the proper experience or evidence-based practices—further complicate access to quality care.
- Comorbidities—Many individuals with a TMD noted challenges with comorbid conditions, including fatigue, widespread pain, fibromyalgia, depression, anxiety, and arthritic conditions.
This brief overview highlights only some of the challenges that continue to be faced by individuals with a TMD and by clinicians in diagnosing TMDs and identifying appropriate care for them. A part of the history of the treatment of TMDs centers on the synthetic implants often used from
the late 1960s to early 1990s to replace the condyle, fossa, and articular disc of the TMJ. Many of these implants were either recalled by the Food and Drug Administration or voluntarily withdrawn from the market after they caused a range of adverse health outcomes including severe pain and functional joint impairment (see Chapter 5).
Patients have played and continue to play a major role in bringing attention to the need to advance the understanding of and ability to treat TMDs.
COMPLEXITY OF TMDs
The TMJs are among the most frequently used joints in the body, often opening and closing approximately 2,000 times daily. All of the critical activities of this joint, ranging from verbal and nonverbal communications to the demanding movements of chewing to the more subtle function of breathing, require healthy functioning of both the TMJs and associated tissues. Additionally, the joints are vital to interpersonal interactions, to the facial expressions of emotions such as joy or sadness, and to self-esteem and self-identification.
During joint movement, the two TMJs act through parallel efforts to move the semi-rigid jaw and connect the mandible to the temporal bone of the skull. The complexity of the varied conditions that are included in the set of disorders known as TMDs has been a challenge for individuals with a TMD, their family members, health care professionals, and researchers. Although these disorders have sometimes been lumped together as one entity (with terms such as temporomandibular joint disorder), recent efforts have focused on emphasizing that this is a set of disorders (see Chapter 2) and therefore that there is no one treatment or one care pathway for TMDs—one “size” does not fit all.
Upon being diagnosed with a TMD, the goals are for each patient to know the specific type of disorder (or multiple TMDs) that he or she has and to be provided with an appropriate treatment plan specific to that diagnosis. The challenge (as described in Chapter 5) is that the evidence base for matching a specific treatment (or group of treatments) with a specific diagnosis is not yet fully developed so that in some cases, particularly for chronic conditions, much remains to be learned. While a small number of abnormalities of the TMJ require specific surgical operations to correct, the majority of TMDs have diffuse symptoms and may not respond predictably to one specific intervention. As discussed in Chapter 3, much also remains to be learned about the prevalence of specific TMDs.
The committee uses the broad definition of TMDs as a set of diseases and disorders related to alterations in the structure, function, or physiology of the masticatory system and that may be associated with other systemic
and comorbid medical conditions. The term “TMDs” is used as an umbrella term to encompass disorders that can range from muscle or joint pain to joint disorders (including hypomobility or hypermobility of the joint) to joint diseases (including osteoarthritis) (see Chapter 2). The pain associated with TMDs can range from none to severe high-impact pain. TMDs can range from a single isolated condition to multi-system involvement and can be associated with other comorbid and systemic disorders and overlapping pain conditions (e.g., fibromyalgia, back pain, headache, irritable bowel syndrome, inflammatory arthritis).
The committee supports a biopsychosocial model of TMDs that is interdisciplinary and can be used across medicine and dentistry to focus on the total person’s health and well-being. The biopsychosocial approach is a broad model that can encompass the range of TMDs and apply the best science from medicine, dentistry, physical therapy, integrative health, and multiple other fields to the care of individuals with a TMD. This approach acknowledges that TMDs are not a single entity and consequently most often have varying causes (e.g., trauma, genetics, environmental etiologies) that affect differing parts of the masticatory system and potentially other body systems and require varied, and sometimes multiple, treatment modalities (see Chapter 5).
NEXT STEPS AND RECOMMENDATIONS
The committee worked to review the scientific literature; to seek information from patients and their family members, researchers, clinicians, policy makers, research funders, and others; to analyze the data; and to develop its conclusions and recommendations.
The recommendations below focus on the actions that many organizations and agencies should take to improve TMD research and care. The committee also emphasizes the critical role that individuals with a TMD and their family members have played—and hopefully will continue to play—in bringing TMD issues to the attention of policy makers and health professionals and moving the research and care agenda forward on multiple levels in the public and private sectors. These efforts are to be commended and are encouraged to continue and expand. Specifically, it is hoped that individuals with a TMD and their families will be able to partner with their health care professionals to find the best options for care, to continue to actively participate in patient support networks, to explore ways to be a participating voice in research efforts, and to be active advocates for improvements in care and services for themselves, their family members, and other people with a TMD. The goals of the following recommendations are to build a strong base of knowledge about TMDs and to facilitate actions needed to improve the overall health and well-being of individuals with a
TMD. Some of these recommendations can be accomplished rapidly with actions by key decision makers. Other recommendations are more aspirational and will require the collaboration and commitment of multiple organizations and dedicated resources—including investments of time, funds, and innovative energies—to accomplish these goals. The committee has provided both short-term and longer-term priorities (see Chapter 8) to be used as starting points and long-range planning points. Key to making a difference in improving care for individuals with a TMD will be:
- pioneering pathways that span medicine, dentistry, physical therapy, and other fields of health care to provide holistic, comprehensive approaches to care—interprofessional and interdisciplinary efforts are of critical importance;
- willingness of health care agencies, organizations, and professionals to commit the resources needed to address this long neglected and often dismissed area of health care; and
- openness and commitment to using and strengthening the evidence base on TMD treatment and changing practice as needed.
Build and Sustain Collaborative and Multidisciplinary Research
Despite investment in research directly and indirectly related to TMDs—most significantly in the field of orofacial pain—researchers have yet to unravel the etiologies and pathophysiologies of TMDs or to translate, in a meaningful way, research findings into improved clinical care practices. Over the past decade, research on TMDs has centered on the biological mechanisms underlying the development and persistence of orofacial pain and on the structure and function of the joint and its tissues, while more recent research has begun to examine the molecular genetics, biomarkers, and biopsychosocial risk factors of TMDs and common comorbidities. Broadly, the research foundation relating to TMDs, as has been the case with other complex, stigmatized conditions, has suffered from the siloing of disciplines and from a lack of clear direction—thus stunting the potential clinical impact of the research. In the case of TMDs, these difficulties have been heightened by a significant dental–medical divide that affects both research and clinical care.
Engagement by multiple stakeholders will be required to dismantle the silos keeping research fields isolated and to advance TMD research and care. A broad range of interrelated research priorities are explored in the report across the research-to-clinical-care continuum. Chapter 4 highlights research priorities, including those that overlap with those of more broadly funded health concerns, such as chronic pain, and emphasizes the importance of keeping patient needs central to the process of research.
The committee recommends that a research consortium be established to bring together relevant National Institutes of Health (NIH) institutes and centers and other stakeholders from the public and private sectors to focus future research efforts on filling key evidence gaps in TMD research and care and to ensure that clinically meaningful, patient-centered outcomes are prioritized. The committee stresses the importance of an organized research approach for TMDs, but the mechanism to carry this out should be flexible.
Fresh ideas and multiple disciplines are needed to advance TMD research to improve patient care. NIH provides approximately one-third of all biomedical research funding in the United States and, therefore, the interests and priorities of NIH institutes and centers can stimulate research interests and training programs throughout the country. TMDs are not the primary mission of any NIH center or institute. NIH funding for TMD research falls largely within the National Institute of Dental and Craniofacial Research (which has one of the smallest research budgets of the NIH institutes) with a total budget of approximately $461 million compared to the National Cancer Institute’s budget of $5.99 billion for fiscal year 2019. Given the number of individuals suffering from TMDs, the severity of some of the disorders, and the substantial public health burden of TMDs, there is a significant opportunity for NIH and other biomedical research institutions to drive increased funding to TMDs in order to spark new research interest and discoveries. Efforts are needed to ensure that TMD research is incorporated into NIH-wide initiatives, including the NIH Pain Consortium. Furthermore, as noted in Public Law 116-94, an NIH inter-institute working group is being called on to focus on coordinating TMD research across the multiple NIH institutes and centers relevant to this field. Details on each of these recommendations is provided in Chapter 8.
Recommendation 1: Create and Sustain a National Collaborative Research Consortium for Temporomandibular Disorders (TMDs)
A National Collaborative Research Consortium for TMDs should be established and sustained to coordinate, fund, and translate basic and clinical research (including behavioral, population-based, and implementation research) to address evidence gaps, generate clinically meaningful knowledge, identify safe and effective treatments, and improve the quality of TMD care.
The consortium would:
- Establish and implement a national research framework for TMDs;
- Provide infrastructure for the implementation of research projects;
- Establish milestones and timelines;
- Facilitate research collaborations;
- Develop public–private partnerships;
- Develop and test evidence-based strategies for knowledge transfer;
- Support the development of a multidisciplinary research workforce for TMDs through existing and new training and center initiatives; and
- Evaluate progress and disseminate research findings.
Recommendations 2 to 4: Coordinate and Expand Research on Temporomandibular Disorders (TMDs)
The National Collaborative Research Consortium for TMDs, led by the National Institutes of Health (NIH) along with other funders, should fund and strengthen:
- Basic research efforts and the translation of that research as part of a patient-focused, multidisciplinary research agenda on TMDs to address evidence gaps, generate clinically meaningful knowledge, identify effective treatments, and improve quality of care;
- The collection, assessment, and dissemination of population-based data on the burden and costs of TMDs and the effects of TMDs on patient outcomes in order to improve the prevention (primary, secondary, and tertiary) and management of TMDs; and
- Clinical and implementation research to clearly define effective treatments and continuously improve the quality of care for patients with a TMD.
Improve Access and Quality for TMD Health Care
The multiple types of TMDs and the extensive comorbidities often seen in patients with TMDs have posed a challenge to clinicians for decades. Correct diagnosis is the first barrier and is complicated further by confusing terminology and a lack of clarity around the causes and development of the disorders (see Chapter 2). Management strategies are equally unclear, with limited or poor-quality data to support treatment decisions and siloed practices that limit the interactions of dental and medical clinicians. Throughout this report, the committee emphasizes a number of important elements of TMD care and awareness, including:
- Patient centeredness, recognizing that individuals with a TMD are more than their medical condition and that quality-of-life factors are important;
- Coordinated and multidisciplinary care as needed that may involve a team of professionals across disciplines; and
- A focus on education, in order to improve clinicians’ knowledge and skills, the general public’s awareness and understanding of TMDs, and the self-management skills of individuals with a TMD.
An important challenge in ensuring the availability of high-quality care for TMDs, particularly for those who have a TMD that is not easily resolved, is making sure that patients have access to coordinated care across medicine, dentistry, and other health professions. Innovative approaches and interprofessional efforts will be needed. Specialized TMD centers, especially for individuals that need multiple types of care, would be vital and could contribute significantly to telehealth options for improving access to specialty care as well as to innovative approaches to health professional education, clinical research, and data collection and analysis. Much remains to be learned about how to individualize patient care to the extent possible in order to provide the most effective management and treatment options for that individual. Details on the following recommendations are provided in Chapter 8.
Recommendation 5: Improve the Assessment and Risk Stratification of Temporomandibular Disorders (TMDs) to Advance Patient Care
The International Network for Orofacial Pain and Related Disorders Methodology, American Dental Association, American Academy of Orofacial Pain, and The TMJ Association, in collaboration with the American Academy of Family Physicians, Society of General Internal Medicine, American College of Rheumatology, and other relevant professional organizations and stakeholders, should develop diagnostic, screening, and risk stratification tools, including a list of high-risk/red-flag symptoms for health care professionals (primary care and dentists) for TMDs. Diagnostic tools and resources for TMDs should be improved for the initial assessment by primary care clinicians and dentists and for referrals to specialists as needed. These efforts should include the development of decision criteria for risk stratification to aid in identifying patients who are likely to escalate from self-limiting and localized symptoms to a systemic pain condition and then to high-impact pain.
Recommendation 6: Develop and Disseminate Evidence-Based Clinical Practice Guidelines and Quality Metrics for Care of Temporomandibular Disorders (TMDs)
The International Association for the Study of Pain, American Academy of Pain Medicine, American Academy of Orofacial Pain, International Network for Orofacial Pain and Related Disorders Methodology, and American Chronic Pain Association should convene stakeholders to develop evidence-based consensus clinical practice guidelines for dentists and primary care clinicians to guide diagnosis, initial treatment, and referral strategies for patients with TMD symptoms. Clinical practice guidelines should be developed and widely disseminated that provide evidence-based pathways for the initial recognition and stepped care management of TMDs and for specialty care for patients with TMDs. Once clinical practice guidelines are developed, clinical performance measures should be deployed in quality improvement initiatives.
Recommendation 7: Improve Reimbursement and Access to High-Quality Assessment, Treatment, and Management of Temporomandibular Disorders (TMDs)
The American Dental Association, in collaboration with The TMJ Association and private and public health insurers (including Medicare and Medicaid) and health professional associations should convene a working group across public and private health and dental insurers and health care systems to develop mechanisms for providing access to consistent, fair, equitable, and appropriate insurance coverage for safe and effective treatments for TMDs. The Center for Medicare & Medicaid Innovation should also conduct demonstration projects that would explore new delivery and payment models for Medicare, Medicaid, and the Children’s Health Insurance Program to improve access, quality, and coverage for TMD care.
Recommendation 8: Develop Centers of Excellence for Temporomandibular Disorders (TMDs) and Orofacial Pain
The American Academy of Orofacial Pain and the existing orofacial pain programs in academic health centers, working with other relevant medical and dental professional associations and with patient advocacy organizations, should develop Centers of Excellence for TMDs and Orofacial Pain to provide comprehensive evaluations and treatment of individuals with TMDs; to serve as a resource for clinicians (including interprofessional consultations and telehealth opportunities); to
contribute to the research base for TMDs; and to provide onsite and virtual education and training, particularly continuing education, for a range of health care professionals. Centers should involve a range of specialists across medicine, dentistry, and other areas of health care and should include patient representatives in the planning and implementation. National Institutes of Health institutes and centers and other research funders should support center-related research through the use of P50 center grants and other relevant funding mechanisms.
Improve Health Care Professional Education About TMDs
A critically important component of improving care for TMD patients is ensuring that health care professionals (across medicine and dentistry) have the professional education and training they need on TMDs—that they have basic knowledge about the set of TMDs and that they are up to date on current research findings and best practices for TMD care. Primary care clinicians—including family physicians, pediatricians, general dentists, nurse practitioners, and physician assistants—need to be well aware that a wide array of disorders are grouped as TMDs and that there are initial care practices (including self-management) that can be useful to many patients. Furthermore, they need to know when to refer patients for specialty care and to which specialists to refer patients.
Additionally, relatively few orofacial pain and TMD specialists are credentialed by independent organizations to provide TMD care. The recommendations below point to actions needed to increase the number of qualified specialists and to provide those specialists with the interprofessional training and expertise needed to equip them to help patients bridge the gaps across medicine and dentistry and obtain full and complete care. Further details on the following recommendations are provided in Chapter 8.
Recommendation 9: Improve Education and Training on Temporomandibular Disorders (TMDs) for Health Care Professionals
Health professional schools and relevant professional associations and organizations across medicine, dentistry, nursing, physical therapy, and all other relevant areas of health care should strengthen undergraduate, graduate, pre- and postdoctoral, residency, and continuing education curricula in pain management, orofacial pain, and TMD care for health professionals and work to ensure interprofessional and interdisciplinary training opportunities.
- Deans of health professional schools (across medicine, dentistry, nursing, physical therapy, and all relevant areas of health) should
ensure that their schools’ curricula include attention to TMDs and cover the physiology, pathophysiology, and assessment, referral, and management of related conditions.
- Health professional licensing organizations (including the organizations administering the National Board Dental Examinations, National Council Licensure Examination, U.S. Medical Licensing Examination, and National Physical Therapy Exam) should expand and improve exam questions about pain management and TMDs, moving beyond physiology and diagnosis and toward treatment and management.
- The Commission on Dental Accreditation should amend the accreditation standards for predoctoral dental programs to include screening, risk assessment, and appropriate evidence-based interventions for TMDs.
- Health professional associations should ensure that all continuing education courses on TMDs for health care professionals are evidence based and reflect and promote current research, clinical guidelines, and best practices.
Recommendation 10: Establish and Strengthen Advanced/Specialized Training in Care of Orofacial Pain and Temporomandibular Disorders (TMDs)
The number and quality of health care professionals with specialized training in pain management, orofacial pain, and TMDs should be increased, recognizing the existence of such barriers as reimbursement and recognition of the practice of orofacial pain.
- The American Dental Association’s National Commission on Recognition of Dental Specialties and Certifying Boards should recognize orofacial pain as a dental specialty.
- The American Board of Medical Specialties, the Accreditation Council for Graduate Medical Education, and the American Society for Pain Management Nursing/American Nurses Credentialing Center’s certification in pain management should ensure that TMDs and TMD care are sufficiently covered in its requirements and certification examination.
- The Commission on Dental Accreditation should work with oral and maxillofacial surgery programs to ensure that participants receive comprehensive training on the surgical and non-surgical management of TMDs, including referral to other health care professionals when appropriate.
- Relevant professional associations should expand and improve opportunities for all health professionals to pursue clinical rotations
and fellowships in pain management, orofacial pain, and TMD care that emphasize interprofessional care.
Raise Awareness, Improve Education, and Reduce Stigma
Individuals with a TMD and their families have contributed significantly to the progress that has been made in TMD research and care. They are among the most persuasive advocates and educators as they have a firsthand picture of the disorder and its impact. There is a need for patients and their families to have consumer-friendly tools and educational resources to enable them to become more informed for their own well-being and, if they so decide, to inform others and advocate for change. Furthermore, efforts are needed to reduce the stigma that is often associated with TMDs. Although there is a limited amount of research on stigma that is specific to TMDs, research on the impact of stigma from chronic pain, together with patient testimony provided to the committee, eloquently document the stigma suffered by individuals with a TMD and its consequences for patients. The committee believes that efforts to increase professional education and awareness about TMDs across the dental and medical professions (see Chapter 6) as well as actions to improve the education of patients, families, and the general public (see Chapter 7) are part of the efforts needed to help reduce the stigma of TMDs and improve patient health and well-being. Chapter 8 provides additional details on implementation actions.
Recommendation 11: Raise Awareness, Improve Education, and Reduce Stigma
The TMJ Association, American Dental Education Association, TMJ Patient-Led RoundTable, American Chronic Pain Association, and American Academy of Orofacial Pain should lead efforts in collaboration with other relevant stakeholders to develop, update, and widely disseminate evidence-based communications and patient-focused tools related to temporomandibular disorders (TMDs). These tools should be strengthened, promoted, and widely disseminated through multiple avenues for adults and youth of all health literacy levels and in multiple languages to raise public awareness about TMDs, improve the resources available to patients and families, and reduce the stigma related to TMDs.
OPPORTUNITIES FOR ACTION
Through commitment, dedicated efforts, and interdisciplinary collaborations, the bold goals outlined in this report (and briefly outlined in Box S-1) can be accomplished to improve the lives of individuals with a TMD.