title: [Clinical research of angle-splitting ostectomy based on three dimensional computed tomography true-up technique].
abstract: OBJECTIVE
  To illustrate the morphological changes of mandible after angle-splitting ostectomy.
  
  
  METHODS
  From January 2006 to April 2008, 10 cases had undergone mandibular angle-splitting ostectomy to reduce the width of the lower face. For each patient, CT datum of mandible at three stages (preoperative, immediate postoperative, 6 months postoperative) were collected. By the application software of reverse engineering (Surfacer V9) and true-up and dissection techniques based on three-dimensional spiral computed tomography (3D-CT), operative efficacy and bone regeneration at the operation area of angle-splitting ostectomy were evaluated 6 months postoperative.
  
  
  RESULTS
  1) Concavity could be seen at the angle-splitting ostectomy area 6 months postoperative, especially at the mandibular external oblique line region. Average cup depth was (3.64 +/- 1.67) mm by contrasted to preoperative. Diminution of bone volume was 55% +/- 9% for the local operative area 6 months postoperative. 2) Bone regeneration could be seen at the area that mandibular outer cortex had been removed. Compared with immediate postoperative, ratio of neoformative bone was 84.6% +/- 7.3% 6 months postoperative. The main region of bone regeneration was mandibular angle.
  
  
  CONCLUSIONS
  Mandibular angle-splitting ostectomy is an effective technique for reducing the width of the lower face. Masseter muscular movement should be restricted postoperative to prevent hyperostosis at the angle area.
authors.affiliation: Dept. of Oral and Maxillofacial Surgery, Dalian City Central Hospital, Dalian 116033, China.
authors.forename: Yan-feng
authors.initials: YF
authors.lastname: Zhao
authors.forename: Yun-fei
authors.initials: YF
authors.lastname: Hao
authors.forename: Ping
authors.initials: P
authors.lastname: Lu
authors.forename: Xiao-nan
authors.initials: XN
authors.lastname: Zhou
authors.forename: Chang-feng
authors.initials: CF
authors.lastname: Qu
mesh_terms: D000328:Adult; D001861:Bone Regeneration; D005145:Face; D005260:Female; D006801:Humans; D008334:Mandible; D008406:Masseter Muscle; D010027:Osteotomy; D014057:Tomography, X-Ray Computed