Metacarpal cortical bone mass in patients with mandibular pain and dysfunction

Sixty consecutive patients with mandibular pain and/or dysfunction were divided in three groups; one group with temporomandibular joint (TMJ) crepitation, another with tenderness on palpation of the TMJ and a reference group without any of these signs. The TM joints of the patients were exposed radiographically in oblique lateral and transmaxillary projections. The hands were exposed in the dorsovolar projection. The metacarpal index of Barnett & Nordin (2) (Formula: see text) was determined from the hand radiographs as well as the Exton-Smith (II) index (Formula: see text) Radiographic abnormalities in the TMJ and hand joints were recorded and quantified in indices as well as clinical abnormalities in the masticatory system. The index of Barnett & Nordin was significantly lower in the group of patients with palpatory tenderness of the TMJ than in the reference group. The Exton-Smith index was significantly and negatively correlated to the radiographic index of hand joint but not TMJ disease. A statistically significant positive correlation was found between the Exton-Smith index and the size of the TMJ condyle. The results of the present study indicate that patients with palpatory tenderness of the TMJ, probably of inflammatory origin, have a smaller second metacarpal cortical bone mass than reference patients, as have patients with radiographic signs of hand joint disease.