Temporomandibular joint abnormalities and bite force in a group of adults with rheumatoid arthritis.

Maximal mouth opening, translatory condylar motion (radiographically assessed) and bite force in sixteen adults with rheumatoid arthritis and radiographic temporomandibular joint abnormalities were compared with data from sixteen individuals without joint disease. Mean mouth opening in the arthritis group was reduced, but not statistically significant. Condylar translation and bite force showed significantly lower values than in the healthy individuals. Maximal mouth opening seemed to be the most uncertain parameter for the estimation of jaw function. In seven patients with a normal mouth opening (40-46 mm), both the condylar translation and the bite force were significantly impaired.