title: Diagnostic ability of extraoral tuned aperture computed tomography (TACT) for impacted third molars.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the capabilities of a newly developed extraoral TACT system for diagnosing impacted third molars.
  
  
  METHODS
  Three dry human mandibles with impacted third molars were used. Nine base images were obtained by the extraoral and intraoral TACT methods. Four board-certified oral and maxillofacial radiologists evaluated TACT slice images as to whether the TACT images could clearly show the periodontal space of the impacted third molar, and the location of the tooth relative to the second molar, or to the mandibular canal. The criteria were excellent, good, fair, poor, and unreadable.
  
  
  RESULTS
  Only the visibility of the periodontal space in extraoral TACT was significantly inferior to that of intraoral TACT. Almost all of the series of TACT images, however, were graded as excellent or good.
  
  
  CONCLUSIONS
  The results indicate that extraoral TACT is a useful modality for the clinical assessment of impacted third molars.
authors.affiliation: Department of Radiology, Showa University School of Dentistry, Tokyo, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Harase
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Araki
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Okano
mesh_terms: D006801:Humans; D008334:Mandible / Q000000981:diagnostic imaging; D008964:Molar, Third / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D019252:Radiography, Dental, Digital / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods; D014095:Tooth, Impacted / Q000000981:diagnostic imaging*