THE STABILITY OF FACIAL OSTEOTOMIES .4. MAXILLARY AND MANDIBULAR (WITH OR WITHOUT CHIN) ADVANCEMENT WITH RIGID INTERNAL-FIXATION

The short-term (6 weeks postoperative) and long-term (12 months postop erative) horizontal skeletal stability of combined maxillary and mandi bular advancement was evaluated by cephalometric analysis of 15 patien ts. The mean horizontal advancement of the maxilla was 5.84 mm. Six we eks later a mean horizontal relapse of 0.03 mm (0.05%) was identified. The mean horizontal relapse at long-term follow-up was 0.59 mm (10.1% ). The mean horizontal advancement of the mandible was 12.35 mm at men ton and 12.65 mm at pogonion. At 6 weeks, mean horizontal relapse, res pectively at the above landmarks, was 0.11 mm and 0.21 mm (1.3%). The mean horizontal relapse at long-term follow-up was 2.19 mm and 1.98 mm (16.6%) respectively for the same landmarks. Subjectively and objecti vely, improvements were seen in facial aesthetics and dental occlusion . The results indicate that rigid fixation of osteotomies undertaken t o correct 'horizontal facial deficiency' is a surgically predictable a nd relatively stable procedure when reviewed up to 12 months after sur gery.