title: Anatomical position of the mandibular canal in relation to the buccal cortical bone in Chinese patients with different dentofacial relationships.
abstract: OBJECTIVE
  The purpose of this study was to determine the position of the mandibular canal in relation to the buccal cortical bone in Chinese patients with three dentofacial relationships: normal dentition, retrognathism, and prognathism.
  
  
  METHODS
  Cone-beam computed tomography and lateral cephalograms of patients with normal dentation, retrognathism, and prognathism (n = 32 each group) were reviewed. Measurements of the shortest distance from the outer/buccal edge of the mandibular canal to the inner surface of the buccal cortex, and the distance from the lingula of the ramus to the dorsal root of the first molar were recorded.
  
  
  RESULTS
  No significant difference was observed between the three groups in the distribution of contact or fusion of the mandibular canal, or in the course of the mandibular canal on the right or left side. When the shortest distance at the lingula on the left side was >2.1 mm, no instances of contact or fusion were observed. On the right side, 100% of the patients had no contact or fusion when the shortest distance was >2.7 mm at the lingula.
  
  
  CONCLUSIONS
  The shortest distance from the outer/buccal edge of the mandibular canal to the inner surface of the buccal cortex measured at the lingula can predict contact or fusion. During sagittal split ramus osteotomy, great care should be observed at the point halfway between the lingula and the anterior ramus border where the inferior alveolar nerve is the closest to the cortical bone.
authors.affiliation: Division of Plastic Surgery, Department of Surgery, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan; Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Chun-Yuan
authors.initials: CY
authors.lastname: Huang
authors.affiliation: Department of Craniofacial Orthodontics, Chang Gung Memorial Hospital, Taoyuan, Taipei, Taiwan; Graduate Institute of Dental and Craniofacial Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan. Electronic address: yfliao0125@yahoo.co.uk.
authors.forename: Yu-Fang
authors.initials: YF
authors.lastname: Liao
mesh_terms: D000328:Adult; D054893:Cone-Beam Computed Tomography; D000071538:Cortical Bone / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008340:Mandibular Nerve / Q000033:anatomy & histology; D059229:Osteotomy, Sagittal Split Ramus; D011378:Prognathism / Q000000981:diagnostic imaging* / Q000601:surgery; D012372:ROC Curve; D063173:Retrognathia / Q000000981:diagnostic imaging* / Q000601:surgery; D012189:Retrospective Studies; D013624:Taiwan; D055815:Young Adult
keywords: inferior alveolar nerve; mandibular canal; prognathism; retrognathism; sagittal split ramus osteotomy