A clinical analysis was performed on 148 patients who underwent orthognathic surgery at the Department of Oral and Maxillofacial Surgery, Nara Medical University for the 15 years from 2002 to 2016. The patients were 51 males and 97 females. Their ages ranged from 16 to 41 years old. The patients less than 25 years old accounted for 64.9％. Mandibular protrusion was the most common clinical diagnosis, made in 84 patients, followed by mandibular protrusion with asymmetry and/or open bite in 31 patients, and facial asymmetry in 16 patients. Le Fort Ⅰ osteotomy＋sagittal split ramus osteotomy （SSRO） was performed in 34 patients, Le FortⅠ osteotomy in 2 patients, SSRO in 111 patients, and mandibular body partial osteotomy in 1 patient. Intraoral vertical ramus osteotomy was unilaterally used in 4 of 145 patients who received SSRO. Genioplasty/genioectomy was performed in 20 patients simultaneously with SSRO. The absorbable osteosynthesis system was principally used for fixation. In Le FortⅠ osteotomy, intraoral plate fixation was exclusively chosen. In SSRO, transcutaneous bicortical screw fixation shifted to intraoral bicortical screw fixation and then to intraoral plate fixation. In genioplasty, intraoral bicortical screw fixation shifted to intraoral plate fixation.
