Dental attrition and degenerative arthritis of the temporomandibular joint.

The extent and rate of occlusal attrition in relation to degenerative arthritis of the temporomandibular joint were studied in 101 skulls representing early Aboriginal man in Australia. Joint degenerations affected 40% of the specimens and were associated with both the rate and extent of tooth attrition. Age, unaccompanied by tooth wear, was not significant in the progress of the disease. Degenerations affected the temporal joint surface more frequently than the condyle, particularly in the lateral and central regions of the articular eminence. Patterns of degenerative joint disease in the Aboriginals illustrated a break-down in the physiological adaptability of the masticatory system resulting from increased occlusal stress consequent upon progressive tooth wear. Under these conditions, the teeth and the temporomandibular joints enter a 'wear-out' phase of occlusal function which usually commences in early adult life and becomes more severe as the conditions continue.