Passive motion therapy in temporomandibular joint disorders: the use of a new hydraulic device and case reports.

To understand the importance of motion on the structural and functional integrity of the temporomandibular joint (TMJ), the effects of immobilization and mobilization on synovial joints are reviewed. Impaired motion has profound deleterious effects on the synovial membrane, articular cartilage, muscles, ligaments, bone, and periarticular connective tissue. Conversely, motion has been shown to be essential to the maintenance of the structural and functional integrity of synovial joints. As in other synovial joints, the relative lack of the stimulus of mobility of the TMJ contributes to pathogenic mechanisms. Restoration of joint mobility is an important principle in the management of TMJ disorders. Illustrative cases are presented in which passive motion therapy, using a new device with a hydraulic mechanism, was successfully used for rehabilitation of TMJ function.