Temporomandibular Joint and Muscle Disorders:
NIH Supports a Wide Range of Research
GAO-08-454R: Published: Apr 4, 2008. Publicly Released: Apr 4, 2008.
Temporomandibular joint and muscle disorders (TMJD) include a heterogeneous group of disorders with overlapping--but not identical--signs and symptoms. Symptoms of TMJDs vary, but typically include pain in the jaw joint and surrounding muscles. Other symptoms may include limited or no movement of the jaw joint, clicking or grating in the jaw joint when opening or closing the mouth, headaches, and shoulder or back pain. Most people with TMJDs have relatively mild forms of these disorders with symptoms that diminish without treatment. However, a small number of individuals develop significant, long-term problems, including persistent and debilitating pain and loss of jaw function. Although some TMJDs are due to a specific known cause, such as jaw injury or arthritis, the causes of many TMJDs are unknown. While the level of understanding about these conditions has evolved with scientific advancements, diagnosis and treatment are difficult because the exact causes and patterns of symptoms remain unclear. The National Institutes of Health (NIH), an agency within the Department of Health and Human Services (HHS), funds research on the causes of, treatments for, and other aspects of TMJDs. The NIH is organized into 27 institutes and centers and the Office of the Director, each with its own mission and functions. Through these institutes and centers, NIH supports both extramural research--conducted at external research institutions by scientists who are awarded funds to support their work--and intramural research conducted by its own scientists. In 1996, NIH sponsored a Technology Assessment Conference that included a panel of experts from a variety of fields, including clinical dentistry, medicine, surgery, immunology, behavioral and social sciences, and pain management. The panel addressed, among other things, the effective management and treatment of patients with TMJDs and the most productive directions for future research, including both applied and basic research. The panel concluded there was a clear need for applied research on a number of issues, including the prevalence of TMJD symptoms, predisposing and precipitating conditions, diagnostic methods, and treatment outcomes. It also concluded that there was a need for basic research in areas such as pain and biomechanics. Noting that TMJDs continue to pose complex health problems for the American public, you expressed interest in the progress that has been made in acting on the panel's conclusions. GAO is reporting on (1) TMJD-related research activities that NIH supported from fiscal year 2002 through fiscal year 2006, and (2) NIH's plans to support future research on TMJDs.
NIH supported a wide range of TMJD-related research from fiscal year 2002 through fiscal year 2006. GAO identified 170 TMJD-related projects supported by NIH during this time period. These projects varied in the types of research activities involved, the institutes and centers that supported them, and the questions the research was designed to investigate. Specifically, NIH supported a variety of different research activities through, for example, grants to support discrete projects performed by investigators in their specific area of interest and grants to support organized efforts of several investigators conducting related research projects. Most of the projects we identified were supported by NIH's National Institute of Dental and Craniofacial Research (NIDCR); nine other institutes and centers and the Office of the Director also supported TMJD-related projects. The research supported by NIH during this time period addressed a wide range of questions related to TMJDs. For example, research addressed questions about the prevalence of TMJD signs and symptoms, predisposing and precipitating conditions, gender differences in TMJDs, pain, and biomechanics. NIH officials told GAO that the agency plans to support future research on TMJDs by continuing to fund research it finds meritorious, including research applications submitted in response to targeted funding announcements. Several targeted funding announcements issued from December 2005 through December 2007 signaled NIH's interest in supporting research in areas involving TMJDs. These announcements either focused directly on TMJDs or addressed research areas, such as pain, that could include TMJDs. Specifically, NIH signaled interest in receiving applications in one area of research that directly focused on TMJDs--the co-occurrence of TMJDs with other chronic conditions, such as chronic fatigue syndrome. During the same 2-year time period, NIH signaled interest in receiving applications addressing 15 other areas of research that identified TMJDs as a possible focus, but did not require investigators to include TMJDs as a focus of their research proposal. NIH officials reported that they may issue additional targeted funding announcements to encourage future research on specific aspects of TMJDs.