Abstract
Sagittal splitting ramus osteotomy is widely used for the correction of mandibular prognathism. There are various procedures for fixation of segments that underwent osteotomy. One of the aims of fixation is to reduce a skeletal relapse after operation. At present, rigid fixations using screw and/or plate are employed in many institutions. However, it has been suggested that these rigid fixations may cause a temporomandibular disorder.
The purpose of this investigation was to compare postoperative positional change and function between screw and plate fixation. The subjects were fifteen patients in whom segments that underwent osteotomy were fixed with positioning screws and fifteen patients in whom segments that underwent osteotomy were fixed with mini-plates. Radiographs which were taken before, immediately after, after three months, six months, and twelve months were analyzed for estimation of positional change. Lateral cephalograms were analyzed for angle of SN-MP, SNB, SN-Pog and ANB. Frontal cephalograms were analyzed for ramus angulation. Submental radiographs were analyzed for condylar angulation. Initial interincisal distance at the releasing time of intermaxillary fixation and trismus (less than 35mm) duration after surgery were also evaluated. Every analytical result was not significantly different between the plate fixation group and the screw fixation group. Therefore, plate fixation of bone segments in sagittal splitting ramus osteotomy may be a useful procedure.
