title: Contributions of reformatted computed tomography and panoramic radiography in the localization of third molars relative to the maxillary sinus.
abstract: OBJECTIVE
  The aim of this clinical study was to seek an answer to the question of whether CT gives better qualitative and quantitative information as compared to panoramic radiograph when deciding on extraction of upper impacted third molars.
  
  
  METHODS
  The study concerned 34 third molars appearing in direct relation with the sinus on the panoramic radiograph for which a CT scan had been recommended. For each case, the panoramic radiograph was compared with the CT scan for 5 evaluation criteria.
  
  
  RESULTS
  The CT scan was more precise than the panoramic radiograph by 1.67 mm for measurement of the level of impaction of the third molar, by 12.44 degrees for measurement of the third molar displacement, by 0.74 mm for bone height separating the third molar roots and the sinus, and by 2.26 mm for the length of roots in the sinus. The CT scan was equally accurate for measurement of the distance separating the crowns of second and third molars in 34 cases.
  
  
  CONCLUSIONS
  This study confirms the gain in precision for the CT scan as compared with conventional techniques. The CT scan therefore presents advantages when considering the extraction of upper third molars by providing both qualitative and quantitative information liable to bear on the diagnosis and therapeutic management.
authors.affiliation: Division of Oral Surgery, Lyon University Dental Hospital, France. bouquetannabelle@yahoo.fr
authors.forename: Annabelle
authors.initials: A
authors.lastname: Bouquet
authors.forename: Jean-Loup
authors.initials: JL
authors.lastname: Coudert
authors.forename: Denis
authors.initials: D
authors.lastname: Bourgeois
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Mazoyer
authors.forename: Denis
authors.initials: D
authors.lastname: Bossard
mesh_terms: D000293:Adolescent; D000328:Adult; D006801:Humans; D021621:Imaging, Three-Dimensional; D008443:Maxillary Sinus / Q000000981:diagnostic imaging*; D008875:Middle Aged; D008964:Molar, Third / Q000000981:diagnostic imaging*; D011861:Radiography, Dental / Q000379:methods*; D011862:Radiography, Panoramic; D036542:Tomography, Spiral Computed; D014081:Tooth Extraction; D014095:Tooth, Impacted / Q000000981:diagnostic imaging*