Arthritis of the temporomandibular joints.

The most common disease of the temporomandibular joint (TMJ) is osteoarthritis. Rheumatoid arthritis and psoriatic arthritis may also involve this joint. Other diseases that may occasionally affect the TMJ include familial Mediterranean fever, systemic lupus erythematosus, gout, Sjögren's syndrome and infectious arthritis. Many cases of TMJ syndrome are labeled as idiopathic facial pain syndrome, a category that probably represents a number of different entities. The role of dental malocclusion has been greatly overemphasized in the past.