title: Condylar surface CT value in sagittal plane before and after sagittal split ramus osteotomy.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the relationship between computed tomography (CT) values of the condylar surface and temporomandibular joint (TMJ) disc position in the sagittal plane before and after sagittal split ramus osteotomy (SSRO) setback surgery, retrospectively.
  
  
  METHODS
  The subjects were 75 patients (150 condyles) who underwent bilateral SSRO setback surgery. They were divided into two groups (42 symmetric patients and 33 asymmetric patients). Maximum CT values (pixel values) of five points of the condylar surface and condylar height, length, fossa height, fossa length, and ramus angle in the sagittal plane were measured preoperatively and 1 year postoperatively. Disc position was classified as anterior disc displacement, anterior type, fully covered type, and posterior type, both pre- and postoperatively, using magnetic resonance imaging (MRI).
  
  
  RESULTS
  Postoperative value was significantly higher than preoperative one in CT value of 135° (P = 0.0199) and 180° (0.0363), in the non-deviation side in the asymmetry group. The anterior disc displacement group was significantly larger than those of some other areas pre- and postoperatively in the CT value of 0° point (P < 0.05).
  
  
  CONCLUSIONS
  This study suggested that CT value of the posterior site of the condylar surface could change in the non-deviation side in the asymmetry group after 1 year SSRO, and the condyle with anterior displacement showed high CT value at the anterior site of the condyle before and after surgery.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School, University of Yamanashi, 1110 Shimokato Chuo, Yamanashi, 409-3893, Japan. 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, 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, 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, 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, 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, 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, University of Yamanashi, 1110 Shimokato Chuo, Yamanashi, 409-3893, Japan.
authors.forename: Asami
authors.initials: A
authors.lastname: Hotta
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School, 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, University of Yamanashi, 1110 Shimokato Chuo, Yamanashi, 409-3893, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Saito
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School, University of Yamanashi, 1110 Shimokato Chuo, Yamanashi, 409-3893, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Fukaya
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School, University of Yamanashi, 1110 Shimokato Chuo, Yamanashi, 409-3893, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Hiraide
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School, University of Yamanashi, 1110 Shimokato Chuo, Yamanashi, 409-3893, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Takayama
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School, University of Yamanashi, 1110 Shimokato Chuo, Yamanashi, 409-3893, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Tsunoda
mesh_terms: D000293:Adolescent; D000328:Adult; D002508:Cephalometry; D003758:Dental Implantation, Endosseous; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008335:Mandibular Condyle / Q000000981:diagnostic imaging*; D008875:Middle Aged; D059229:Osteotomy, Sagittal Split Ramus / Q000379:methods*; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011378:Prognathism / Q000601:surgery*; D012189:Retrospective Studies; D019224:Temporomandibular Joint Disc / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D014081:Tooth Extraction; D055815:Young Adult
keywords: Computed tomography (CT) value; Condyle; Disc position; Sagittal plane; Sagittal split ramus osteotomy