Stability after Bimaxillary Orthognathic Surgery with Rigid Fixation

Bin, Chul Won; Park, Sanghoon; Yoon, Kun Chul; Park, In Kwon

Abstract

After bimaxillary orthognathic surgery for correction of facial deformity, the factors influencing stability of bone segment are the amount of bone segment, surgical technique, fixation technique, rotation of proximal segment. The aim of this study is to analyze the significance of the factors influencing skeletal relapse after bimaxillary orthognathic surgery. From March 1994 to march 2003, 11 patients who underwent bimaxillary procedures without genioplasty or any other orthognathic surgical procedures were included for sample. Lateral cephalograms were analyzed before surgery, 1 month and 12 months after surgery respectively. Vertical, horizontal, angular and dental measurements were obtained from each tracing using the horizontal and vertical reference lines. The mean amount of bone movement and relapse was 7.03mm, 2.44mm (35%) respectively at pogonion and 3.41mm, 0.6mm (18%) respectively at point A. After statistical analysis of collected data, the amount of skeletal movement, fixation technique were significantly related to relapse, but rotation of proximal segment, surgical procedures were not significantly related to relapse. Then we suggest that when operation is planned, 20-30% overcorrection was recommended at the time of bimaxillary surgery.