Bone change in the temporomandibular joint in patients with temporomandibular joint disorders. With special reference to the loss of premolar-molar support

Bone change in the temporomandibular joint (TMJ) in 540 patients with TMJ disorders was studied radiographically in relation to the loss of premolar and/or molar support.The incidence of bone change (erosion or deformity) which was observed in 49. 404 of the patients was higher in female patients and showed a tendency to increase in older pati-ents. The bone change was noted in the symptomatic side in 72.3%, in the asymptcmatic side in 13.5% and bilaterally in 14.2% with an increase of bilateral involvement in older patients. The joint pain and the limited range of motion of the mandible were seen significantly higher in patients with bone change at the initial examination. The bone change was observed in 56.4% of patients with loss of premohr and/or molar support which was significantly higher than 40.4% of the patients without loss. The number of patients with loss of premolar and/or molar support and the incidence of bone change seen in these patients increased with age.The results indicate that the loss of premolar and/or molar support is one of the factors leading to bone change in TMJ