Evaluation of internal derangement of the temporomandibular joint by panoramic radiographs compared with magnetic resonance imaging.

INTRODUCTION Panoramic radiographs are routinely used in orthodontic diagnosis and treatment planning. It would be useful if these radiographs could also provide information about internal derangement (ID) of the temporomandibular joint (TMJ). METHODS The sample consisted of 168 condyles in 84 women. They underwent panoramic radiography on 1 of 3 machines and bilateral magnetic resonance imaging of the TMJ on 1 machine. Six panoramic variables were analyzed by 2-factor ANOVA to evaluate differences in condylar morphology with respect to status of the TMJ ID and type of panoramic machine. RESULTS Decreased condylar heights and distally inclined condyles were found in the patients with TMJ ID, irrespective of the type of panoramic machine used. The change became more severe as ID progressed to disk displacement without reduction. CONCLUSIONS This study suggests that some panoramic variables can help the clinician identify patients with potential ID.