Temporomandibular disorders comprise a collection of medical conditions affecting one or both jaw joints and/or their associated muscles and other tissues. Symptoms include pain and difficulties in making normal jaw movements, such as those used in speaking, chewing, swallowing or forming facial expressions.
The two temporomandibular joints, located in front of the right and left ears, connect the lower jaw, the mandible, to the temporal bone of the skull. They are the most complex joints in the body, richly endowed with nerves and muscles that allow coordinated movements in three dimensions. Jaw injuries and various forms of arthritis can give rise to TMJ Disorders but in general, the cause or causes (etiology) of TMJ Disorders is unknown.
What is known that these disorders are more prevalent in women, occurring during the childbearing years, and that the female to male ratio of those affected increases with the severity of the disorder so that for patients with the most severe chronic and painful TMJ Disorders the ratio of females-to-males approaches 9:1.
Traditionally patients with jaw problems have been seen by or referred to general dentists or oral surgeons, who have often sought to remedy the problem by altering the teeth or operating on the jaw. The TMJ Association (TMJA) was formed in 1986 as a patient support group in Milwaukee concerned with the lack of understanding of etiology and the multiple but unproven treatments in use—some of which caused even greater pain and disability. TMJA has since grown into a national nonprofit advocacy organization promoting research, education, and support of patients and their families. Through the Association’s efforts, the National Institutes of Health has issued a “less is best” recommendation urging patients to avoid invasive procedures such as jaw surgery, if at all possible, and has increased TMJ research. There is greater attention to the interplay of gender, genetics, environmental and behavioral factors in the etiology of TMJ Disorders and a major study is underway exploring risk factors.
Over the decade, the Association has sponsored eight scientific meetings in conjunction with the National Institutes of Health aimed at expanding the base of TMJ science and making recommendations for further research. There is now consensus that the TMJ Disorders represent a complex family of disorders best studied with a systems approach in which investigators from many disciplines work as a team, exploring all aspects of the disorder from genes and molecules to the whole person living in an environment.
At one of our most recent meetings it explored the finding that many TMJ patients experience one or more other systemic conditions that also predominantly or exclusively affect women, including chronic fatigue syndrome, endometriosis, fibromyalgia, generalized pain conditions, interstitial cystitis, irritable bowel syndrome, rheumatoid arthritis, and vulvodynia. Scientists at the meeting were enthusiastic that discovering a common pathway linking these overlapping conditions would have the potential of leading to a therapy that might benefit all of them.
As research advances to understand more about TMD, many in the health care community are reassessing past treatments and ways in which they were developed. As noted earlier, there is a growing consensus of health professionals who consider TMD a complex family of conditions like hypertension or diabetes. In that regard, the TMD patient should not be seen as someone with an isolated dental or jaw condition but rather viewed as a whole individual subject to genetic, hormonal, environmental and behavioral factors that may be contributing not only to jaw pain and dysfunction, but to a range of other serious comorbid conditions.
In some cases, the patient may experience one condition initially and then go on to develop one or more comorbidities. In other cases, two conditions may occur together at the outset. Such a perspective can direct and inspire scientists to discover commonalities that can advance understanding and ultimately lead to beneficial therapies.
Research to understand why these conditions coexist is in its early stages, but it is already prompting leading investigators to propose a name change. “TMD” is not an apt term to describe the complex multisystem pains and dysfunctions that many patients experience. The thinking now is that these debilitating problems experienced in various parts of the body have their origin in pathology at the highest levels of the brain and central nervous system.
The TMJ Association continues to advocate for research for solutions to TMD and the medical conditions that frequently co-occur it, as well as for the development of safe and effective diagnostics and treatments. We will keep you updated on the latest scientific research findings through our website and we invite you to visit often.