title: Clinical significance of computed tomographic assessment and anatomic features of the inferior alveolar canal as risk factors for injury of the inferior alveolar nerve at third molar surgery.
abstract: OBJECTIVE
  To assess the clinical features of the inferior alveolar canal (IAC) using computed tomography (CT) and to analyze the significance of CT examination at third molar surgery.
  
  
  METHODS
  A retrospective cohort study was performed involving 99 patients (145 teeth). The relationship between cortication status, buccolingual position, and shape of the IAC on the CT image and inferior alveolar nerve (IAN) injury after third molar surgery were statistically analyzed.
  
  
  RESULTS
  The shape of the IAC was categorized into 3 groups: round/oval, teardrop, and dumbbell. IAN injury was observed in 7 of 145 cases (4.8%). All 7 cases exhibited absence of cortication; 3 were dumbbell shape and 4 were round/oval. According to logistic regression analysis of cases with absence of cortication, IAC shape was closely related to IAN injury.
  
  
  CONCLUSIONS
  These results suggest that assessment of the IAC shape and cortication status at third molar surgery may be clinically useful.
authors.affiliation: Department of Oral Surgery, School of Medicine, Sapporo Medical University, Sapporo, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Ueda
authors.forename: Kenji
authors.initials: K
authors.lastname: Nakamori
authors.forename: Kaori
authors.initials: K
authors.lastname: Shiratori
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Igarashi
authors.forename: Takanori
authors.initials: T
authors.lastname: Sasaki
authors.forename: Naoki
authors.initials: N
authors.lastname: Anbo
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kaneko
authors.forename: Naohiro
authors.initials: N
authors.lastname: Suzuki
authors.forename: Hironari
authors.initials: H
authors.lastname: Dehari
authors.forename: Tomoko
authors.initials: T
authors.lastname: Sonoda
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Hiratsuka
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000294:innervation; D008340:Mandibular Nerve / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008875:Middle Aged; D008964:Molar, Third / Q000294:innervation / Q000601:surgery*; D011237:Predictive Value of Tests; D019252:Radiography, Dental, Digital / Q000295:instrumentation / Q000379:methods; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014081:Tooth Extraction / Q000009:adverse effects*; D061221:Trigeminal Nerve Injuries / Q000517:prevention & control*; D055815:Young Adult