Computed tomography morphology of the mandibular ramus in prognathism: effect on the medial osteotomy of the sagittal split ramus osteotomy.
OBJECTIVE
The purpose of this study was to investigate the distribution of cancellous bone relative to performance of the medial osteotomy of a sagittal split ramus osteotomy using computed tomography scanning.


METHODS
Skeletal Class III patients consisted of 11 males and 22 females with a mean age of 23 years. The control patients without dentofacial deformity consisted of 10 males and 20 females with a mean age of 25 years. Scans were taken parallel to the mandibular occlusal plane, and morphologic measurements, including distribution of cancellous bone, were obtained.


RESULTS
Compared with the control patients, the mandibular ramus of Class III patients was thinner with a more complicated and varied cancellous bone pattern, such as separate regions of cancellous bone and lack of cancellous bone posterior and anterior to the mandibular foramen.


CONCLUSIONS
It was apparent that the safest region in which to establish the medial osteotomy line was just superior and 5 to 6 mm posterior to the lingula, directing the line slightly inferior.
Muto
Toshitaka
T
Department of Oral Surgery, School of Dentistry, Health Sciences University of Hokkaido, Hokkaido, Japan. muto@hoku-iryo-u.ac.jp
Shigeo
Kimiharu
K
Yamamoto
Keiko
K
Kawakami
Johji
J
D000293:Adolescent; D000328:Adult; D002508:Cephalometry; D005260:Female; D006801:Humans; D008297:Male; D008313:Malocclusion, Angle Class III / Q000000981:diagnostic imaging / Q000601:surgery; D008334:Mandible / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D010027:Osteotomy / Q000379:methods*; D010347:Patient Care Planning; D011378:Prognathism / Q000000981:diagnostic imaging* / Q000601:surgery; D013223:Statistics as Topic; D014057:Tomography, X-Ray Computed