title: Third molar position: reliability of panoramic radiography.
abstract: OBJECTIVE
  The purpose of the present study was to determine whether panoramic radiographs could predict physical contact between the mandibular third molar and the mandibular canal on limited cone-beam computed tomography, known as dental 3D-CT (3-dimensional computed tomography [3D-CT]).
  
  
  METHODS
  The association of images between the panoramic radiograph and the dental 3D-CT was investigated in a cross-sectional study. Seventy-three lower third molars in 65 patients were examined. Findings of absence or presence of the white line of the mandibular canal wall on panoramic radiographs and contact or separation between the tooth and the mandibular canal on dental 3D-CT were compared.
  
  
  RESULTS
  Absence of a superior white line on panoramic radiography was associated with an increased risk of contact between the third molar and the mandibular canal on dental 3D-CT, even when the effects of tooth position, age, and gender were taken into account. The multivariate adjusted odds ratio was 10.79. Women were more likely to have contact between the 2 structures on dental 3D-CT when their panoramic radiograph showed absence of the white line.
  
  
  CONCLUSIONS
  Panoramic radiography is useful for predicting to a limited extent physical contact between the mandibular third molar and the mandibular canal on dental 3D-CT.
authors.affiliation: Second Department of Oral and Maxillofacial Surgery, Tsurumi University School of Dental Medicine, Yokohama, Japan. nakagawa-y@tsurumi-u.ac.jp
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Nakagawa
authors.forename: Hisako
authors.initials: H
authors.lastname: Ishii
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Nomura
authors.forename: Nobuyuki Y
authors.initials: NY
authors.lastname: Watanabe
authors.forename: Daigo
authors.initials: D
authors.lastname: Hoshiba
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Katsunori
authors.initials: K
authors.lastname: Ishibashi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging*; D008340:Mandibular Nerve / Q000000981:diagnostic imaging*; D008875:Middle Aged; D008964:Molar, Third / Q000000981:diagnostic imaging*; D011862:Radiography, Panoramic; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods