Temporomandibular (TMJ) disorders, which typically affect more females than males, arise from a highly complex biological interplay that involves myriad factors which possibly mask or modify the symptoms of the TMJ problem. With so many variables, some researchers have suggested the best scientific entry point to examine and ultimately identify the elements of a TMJ disorder is during its earliest stages, before the full-blown complexity of advanced disease clouds the investigative picture. Five years ago the National Institute of Dental and Craniofacial Re-search (NIDCR) supported the launch of the Orofacial Pain: Prospective Evaluation and Risk Assessment project, or OPPERA. It marks the first-ever large, prospective clinical study to identify risk factors that contribute to the development of a TMJ disorder.
In the Clinical Journal of Pain (February 2010), NIDCR grantees and colleagues published the results from a separate pilot natural history study that helped lay the scientific groundwork for the larger OPPERA trial. The paper presents 3-year data from a large cohort of women between the ages of 18 and 34 years who began the study with no history of TMJ disorders (TMD). The researchers found that 16 of the study’s 266 participants developed a TMD condition, totaling 6% of enrollees. They note that this percentage is comparable to the 3-year results of another previous longitudinal study. The researchers also found that the 16 women who developed TMD also self-reported significant increases in headaches, muscle, and other pain. Interestingly, these women also collectively reported at baseline more experience with joint, back, chest, and menstrual pain compared to other participants.
“These findings are in agreement with various case-control studies which have suggested that it seems inappropriate to consider TMD in isolation,” the authors concluded. “Rather, regional and widespread chronic pain conditions represent ‘overlapping’ conditions and should be considered as part of a ‘continuum’ [rather] than distinct entities with distinct etiologies. That being said, there are also other risk factors unique to the development of TMD such as bruxism [teeth grinding], history of facial trauma, and third-molar extraction, which may not present as significant risk factors for the development of pain in other areas of the body.”
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