title: Correlation of panoramic radiography and cone beam CT findings in the assessment of the relationship between impacted mandibular third molars and the mandibular canal.
abstract: OBJECTIVE
  The aim of this study was to assess the reliability of four panoramic radiographic findings, both individually and in association, in predicting the absence of corticalization between the mandibular canal and the third molar on cone beam CT (CBCT) images.
  
  
  METHODS
  The sample consisted of 72 individuals (142 mandibular third molars) who underwent pre-operative radiographic evaluation before extraction of impacted mandibular third molars. On panoramic radiographs, the most common signs of corticalization (darkening of roots, diversion of mandibular canal, narrowing of mandibular canal and interruption of white line) and the presence or absence of corticalization between the mandibular third molar and the mandibular canal on CBCT images were evaluated.
  
  
  RESULTS
  Darkening of roots and interruption of white line associated with the absence of corticalization between the mandibular third molar and the mandibular canal on CBCT images were statistically significant, both as isolated findings (p = 0.0001 and p = 0.0006, respectively) and in association (p = 0.002). No statistically significant association was observed for the other panoramic radiographic findings, either individually or in association (p > 0.05).
  
  
  CONCLUSIONS
  Darkening of roots and interruption of white line observed on panoramic radiographs, both as isolated findings and in association, were effective in determining the risk relationship between the tooth roots and the mandibular canal, requiring three-dimensional evaluation of the case.
authors.affiliation: State University of Campinas, Department of Oral Diagnosis, Piracicaba, Sao Paulo, Brazil. fredsampaio@yahoo.com.br
authors.forename: F S
authors.initials: FS
authors.lastname: Neves
authors.forename: T C
authors.initials: TC
authors.lastname: Souza
authors.forename: S M
authors.initials: SM
authors.lastname: Almeida
authors.forename: F
authors.initials: F
authors.lastname: Haiter-Neto
authors.forename: D Q
authors.initials: DQ
authors.lastname: Freitas
authors.forename: F N
authors.initials: FN
authors.lastname: Bóscolo
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D054893:Cone-Beam Computed Tomography / Q000706:statistics & numerical data*; D005260:Female; D005544:Forecasting; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000706:statistics & numerical data; D021621:Imaging, Three-Dimensional / Q000706:statistics & numerical data; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging*; D008964:Molar, Third / Q000000981:diagnostic imaging*; D015588:Observer Variation; D011862:Radiography, Panoramic / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D018570:Risk Assessment; D014092:Tooth Root / Q000000981:diagnostic imaging; D014095:Tooth, Impacted / Q000000981:diagnostic imaging*; D055815:Young Adult