A Survey of Subjects with Jaw Deformities during the Past 15 Years in Orthodontic Science, Department of Orofacial Development and Function at Tokyo Medical and Dental University

Abstract

A statistical survey, by the Orthodontic Science, Department of Orofacial Development and Function at Tokyo Medical and Dental University, was performed on 626 subjects with jaw deformities who underwent orthodontic treatment in association with orthognathic surgery from 1997 to 2011. The results were as follows:
1. There were 266 males and 360 females (ratio: 1:1.35).
2. 50.2% of subjects lived in Tokyo.
3. The mean age at surgery was 25.8 years old. The number of subjects who are 31 years or older has tended to increase in recent years.
4. The most common condition was mandibular prognathism without anterior open bite, which accounted for 68.1% of the subjects. The second common condition was mandibular prognathism with anterior open bite, which accounted for 16.8%.
5. The most frequently used surgical technique was sagittal split ramus osteotomy (SSRO), which accounted for 55.4%. The combination of Le Fort I osteotomy and SSRO accounted for 36.3%.
6. The most common bone fixation technique after SSRO was screw- or miniplate-fixation.