Multiple-segment
osteotomy is defined as an
osteotomy that divides the tooth-bearing arch of the maxilla or mandible into three or more segments. Combining large-segment
orthognathic surgery and unitooth or small-segment surgery is an effective approach for dealing with a wide range of
dentofacial deformities with occlusal problems. The indications for a multiple-segment
osteotomy included
dentofacial deformities and
malocclusions requiring stable correction within a short overall treatment period. From 1991 to 1997, a total of 85 patients had multiple-segment
osteotomy orthognathic procedures performed at Chang Gung Memorial Hospital. The indications for surgery were maxillary protrusion/
deformity (31 patients), mandibular
prognathism (51 patients), and noncleft
maxillary retrusion (three patients). The types of
osteotomies performed were Le Fort I, anterior segmental
osteotomies of the maxilla or the mandible, palatal split, posterior segment, and unitooth or
double-tooth segments. Follow-up ranged from 6 months to 7 years; stability was seen in movements, with only three complications (one partial gingival loss and two inferior mental
paresthesias). No osteotomized segments were lost. The average overall treatment time was approximately 15 months, including 3 to 6 months of preoperative and 9 to 12 months of postoperative orthodontic treatment. This is at least 6 months shorter than traditional
orthognathic surgery. Experience with 85 consecutive patients has shown that the results are good and the procedure is safe, with minimal complications.