A comparison of wire osteosynthesis and screw fixation in the stability of bimaxillary osteotomies

This study compared stability of rigid and nonrigid fixation in patients who underwent simultaneous sagittal split mandibular advancement and Le Fort I maxillary impaction. Immediately postoperative, 6-month, and 1-year follow-up cephalograms were used in the assessment. Slight inferior settling of the posterior end of the maxilla was detected in the nonrigid fixation group, but the maxilla generally stayed within 1 mm of its immediately postsurgical position in both groups. At the 6-month follow-up, the rigid fixation group averaged 2.5 degrees of clockwise mandibular rotation without any change in the gonial angle. In the nonrigid fixation group, the distal segment had rotated in a clockwise direction with an increase in the gonial angle of 3.0 degrees. No further changes were detected in the rigid fixation group, whereas the mandible continued its clockwise rotation in the nonrigid fixation group. These results support the belief that rigid fixation is more stable than wire osteosynthesis. The merits of assessing cephalograms with finite element and Euclidean distance matrix analyses to evaluate surgical changes and stability are discussed