A proposed classification of temporomandibular disorders based on synovial joint pathology

Classifying temporomandibular disorders is essential for descriptive and diagnostic reasons. The etiology of many temporomandibular joint (TMJ) disorders is unknown and lack of scientific agreement about etiologic concepts contributes to controversies about the real nature of TMJ disorders. Although many classifications have been suggested, mostly based on etiologic assumptions, a generally accepted classification is not yet available. Considering the TMJ as a true synovial joint, comparable to all other joints in the body, implies that the classification of disorders of the masticatory system should be consistent with the approach to musculoskeletal disorders in other parts of the body. Based on this criterium and on the considerable amount of information available in the literature, a classification of TMJ disorders is here proposed for general use.