Surgical refinement of the operative procedure for a minor degree of mandibular prognathism.

Although sagittal splitting ramus osteotomy is used widely for mandibular prognathism and even for that of a minor degree, a long duration of preoperative and postoperative orthodontic treatment is required. Conversely, mandibular segmental osteotomy has often been used to correct a minor degree of mandibular prognathism without specific orthodontic treatment. Here we describe a surgical refinement accomplishing mandibular segmental osteotomy, reduction genioplasty by double horizontal osteotomies, and decortication of the middle portion of the osteotomies for a minor degree of mandibular prognathism. The amount of setback is limited to 4 to 5 mm, no intermaxillary fixation is required, and no orthodontic treatment, in principle, is needed. This procedure can obtain a rapid aesthetic improvement. We used this procedure in 11 patients (7 females and 4 males) with a minor degree of mandibular prognathism. The amount of setback of the mandibular anterior portion was 4 to 5 mm, and satisfactory results were obtained in all patients.