Temporomandibular joint symptoms in an orthognathic surgery population

The records of 317 consecutive patients who underwent orthognathic surgery in the Division of Maxillo-Facial Surgery of the General Hospital St. John, Bruges, Belgium, between 1.10.90 and 1.10.92 were evaluated for pre- and postoperative temporomandibular joint (TMJ) symptoms. Only 143 patients, with a normal/low angle mandibular deficiency deformity, treated by mandibular advancement, and 53 high angle absolute mandibular retrognathism patients having bimaxillary operations, were selected. Fewer TMJ symptoms were found postoperatively, than preoperatively in the total group (17.8% vs 26.5% p = 0.025, Mc Nemar). In the normal/low angle group, there was a decrease in TMJ symptoms after surgery from 30.0% to 14.6% (p = 0.0001, Mc Nemar). In the high angle group, however, more TMJ symptoms are seen postoperatively 26.4% versus 16.8% (p = 0.228, Mc Nemar). Possible hypothetical explanations are given.