A clinical analysis was performed on 231 patients with jaw deformities who had undergone orthognathic surgery in the Department of Oral and Maxillofacial Surgery, School of Dentistry, Health Sciences University of Hokkaido from November 2002 to March 2017. The results were as follows:
1. The patients were 63 males and 168 females (male to female ratio of 1:2.66).
2. The mean age at the time of operation was 25.4±10.0 years (range: 15–58 years).
3. The diagnosis of mandibular prognathism was made for most patients (125 cases: 54.1%).
4. The most common surgical method was sagittal split ramus osteotomy (SSRO) (133 cases: 55.6%), followed by the combination of Le Fort I osteotomy (LF I)+SSRO (51 cases: 21.3%).
5. The average time of operation for SSRO was 133.7±36.5 minutes and that for SSRO+LF I was 282±57.4 minutes.
6. The average amount of bleeding was 143.7±188.5ml for SSRO and that for SSRO+LF I was 266.9±184.3ml.
7. Blood transfusion was performed in about 13.8% of the patients, and all cases were preoperative hemodilution autotransfusion.
