Association between temporomandibular disorders and pain in other regions of the body.

The pain from temporomandibular disorder (TMD) is often associated with physical symptoms of other chronic pain disorders and comorbidities, such as generalised muscle and joint pain. However, this association is not widely studied. To evaluate the prevalence of comorbid pain in joints, specifically in the knees, hips, ankles, shoulders, wrists and elbows, in individuals with and without TMD. We evaluated 337 patients from a public hospital in the city of Rio de Janeiro, Brazil. The Research Diagnostic Criteria for TMD questionnaire were used for the diagnosis of TMD. To assess the presence of other joint pain, the patients were asked to answer questions considering: the presence of pain in the knee, hip, ankle, shoulder, wrist and elbow joints and time duration of pain. Individuals with TMD are 5·5 times more likely to present with other joint pain compared with those without the disorder. TMD muscle disorders were most associated with a higher number of pain at the other locations. There was a significant association between the presence of pain at the other locations, muscle (P < 0·001) and joint disorders (P = <0·001), as well as age advance, in TMD participants, showed to be a covariate factor for pain at the other locations. Individuals with TMD showed a high prevalence of pain in other joints of the body when compared with individuals without the disorder, and knee pain was the most prevalent pain complaint.