title: The three-dimensional assessment of dynamic changes of the proximal segments after intraoral vertical ramus osteotomy.
abstract: OBJECTIVE
  The aim of this study was to assess the positional changes of the proximal segments after intraoral vertical ramus osteotomy (IVRO).
  
  
  METHODS
  Fifteen patients underwent IVRO and were followed according to the authors' unique postoperative management regimen. The analyses of the positions and angles of the proximal segments were performed on frontal and lateral cephalograms, which were taken before surgery (T1) and within 3 days (T2), at 4 weeks (T3), and later than 6 months after surgery (T4). The three-dimensional positions of the condylar heads were also assessed by CT images, which were taken before and 1 year after surgery.
  
  
  RESULTS
  The proximal segments temporarily swung posteriorly and laterally with a center on the condylar head as a fulcrum point at T2 and T3, compared with T1, and they repositioned at T4. The condylar heads moved inferior approximately 2 mm with lateral rotation one year after surgery, as seen in the CT.
  
  
  CONCLUSIONS
  The condylar heads changed their positions physiologically for newly established jaw movement after IVRO with the authors' post-operative management regimen because the post-operative skeletal stability and the jaw function were good and stable using this method.
authors.affiliation: Department of Regenerative Oral Surgery, Nagasaki University Graduate School of Biomedical Sciences , Japan.
authors.forename: Seigo
authors.initials: S
authors.lastname: Ohba
authors.forename: Noriko
authors.initials: N
authors.lastname: Nakao
authors.forename: Kousuke
authors.initials: K
authors.lastname: Awara
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Tobita
authors.forename: Tokutarou
authors.initials: T
authors.lastname: Minamizato
authors.forename: Takako
authors.initials: T
authors.lastname: Kawasaki
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Koga
authors.forename: Yuya
authors.initials: Y
authors.lastname: Nakatani
authors.forename: Noriaki
authors.initials: N
authors.lastname: Yoshida
authors.forename: Izumi
authors.initials: I
authors.lastname: Asahina
mesh_terms: D000293:Adolescent; D000328:Adult; D002508:Cephalometry / Q000379:methods*; D005081:Exercise Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008334:Mandible / Q000473:pathology; D008335:Mandibular Condyle / Q000473:pathology*; D063168:Mandibular Osteotomy / Q000379:methods*; D017090:Occlusal Splints; D012399:Rotation; D013701:Temporal Bone / Q000473:pathology; D013704:Temporomandibular Joint / Q000473:pathology; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult
keywords: Condyle; Intraoral vertical ramus osteotomy; Proximal segment; Three-dimensional assessment