Effects of wire and miniplate fixation on mandibular stability and TMJ symptoms following orthognathic surgery

The effects of wire and miniplate fixations on mandibular stability and temporomandibular joint (TMJ) symptoms were analyzed in 145 patients in whom mandibular prognathism had been corrected by the bilateral sagittal split osteotomy (BSSO). The subjects were divided into two groups based on the method of fixation. Group I consisted of 105 patients treated with intraosseous wiring and group II consisted of 40 patients treated with titanium miniplates. The mean maxillomandibular fixation periods for groups I and II were 48 days and 23 days, respectively. Lateral cephalograms were taken immediately before surgery, within a week after surgery, and at least a year after surgery. Changes in the positions of the incisal edge of the lower central incisors, point B, pogonion, and menton were examined. TMJs were examined clinically for pain, sounds, movements, and limitations before treatment and at least a year after surgery. In both groups, the mean of the horizontal relapses was correlated to the magnitude of their surgical movements. In group II, the mean horizontal relapse was smaller, but not significantly more than that of group I. There was no statistical difference in the pre- and postoperative incidence of TMJ signs and symptoms between the two groups. It can be concluded that miniplate fixation for the BSSO procedure has the advantages of shortening the maxillomandibular fixation period and maintaining the postoperative stability of the mandible without causing adverse effects on the TMJ.