title: Change in mandibular body height at the site of a fixation plate in the advance (lengthening) and setback (shortening) sides after sagittal split ramus osteotomy.
abstract: OBJECTIVE
  The purpose of this study was to evaluate changes in mandibular body height at the site of a fixation plate in the advance (lengthening) and setback (shortening) sides after sagittal split ramus osteotomy (SSRO).
  
  
  METHODS
  The subjects were 49 patients (98 sides) who underwent bilateral SSRO surgery. The subjects were divided into 4 groups as follows, setback (shortening) sides in mandibular prognathism (Prog S group; n = 42), advancement (lengthening) sides in mandibular retrognathism (Retro L group; n = 24), setback (shortening) sides in mandibular asymmetry (Asym S group; n = 16) and advancement (lengthening) sides in mandibular asymmetry (Asym L group; n = 16). Postoperative computed tomography (CT) was analyzed for all patients pre-operatively, and at 1 week and 1 year postoperative. Mandibular body height at the site of the fixation plate, mandibular upper height above the plate and mandibular lower height under the plate were measured by 3-dimensional (3D) CT.
  
  
  RESULTS
  There were no significant differences in mandibular height between the lengthening and shortening sides in mandibular prognathism, retrognathism and asymmetry in the time-course change. Upper mandibular height at the mid-point of the fixation plate after 1 year was significantly smaller than that after 1 week in all sides (P < 0.05).
  
  
  CONCLUSIONS
  This study suggested that slight bone resorption could occur at the upper site of a fixation plate after set back and advancement SSRO.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan. Electronic address: kueki@yamanashi.ac.jp.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Ueki
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
authors.forename: Kunio
authors.initials: K
authors.lastname: Yoshizawa
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Moroi
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
authors.forename: Ran
authors.initials: R
authors.lastname: Iguchi
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kosaka
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
authors.forename: Hiroumi
authors.initials: H
authors.lastname: Ikawa
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Tsutsui
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Saida
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
authors.forename: Asami
authors.initials: A
authors.lastname: Hotta
mesh_terms: D000293:Adolescent; D000328:Adult; D001860:Bone Plates; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000033:anatomy & histology* / Q000601:surgery; D008875:Middle Aged; D059229:Osteotomy, Sagittal Split Ramus; D011378:Prognathism / Q000601:surgery*; D055815:Young Adult
keywords: Computed tomography; Mandibular body height; Sagittal split ramus osteotomy