title: Cone-beam Computed Tomography: Anatomic Analysis of Maxillary Posterior Teeth-Impact on Endodontic Microsurgery.
abstract: BACKGROUND
  It is imperative that the endodontic surgeon be knowledgeable of the anatomic dimensions of the surgical site. If cone-beam computed tomography is not available because of location/cost, it is prudent for the clinician to consult a knowledge base for the surgical site. An understanding of the root thickness of maxillary premolars and molars at the preferred level for root resection (3.0-3.6 mm), bone thickness over these roots, and the proximity of each root apex to the maxillary sinus will help the surgeon before and during the surgical procedure.
  
  
  METHODS
  Cone-beam computed tomography scans from 155 patients were used to evaluate measurements from 505 teeth and respective areas.
  
  
  RESULTS
  (1) Buccal bone was thinnest over the buccal root of the 2-rooted first premolar (0.66 mm) and the mesiobuccal (MB) root of the first molar (0.84 mm) and thickest over the MB root of the second molar (1.91 mm). (2) The palatal bone was thinnest over the palatal root of the maxillary first molar (1.24 mm) and thickest over the single-rooted second premolar (3.26 mm). (3) The longest distances to complete resection were found for the 2-rooted first and second premolars (8.81 mm and 9.14 mm, respectively) and the MB root of the second molar (7.40 mm). (4) The MB root of the second molar had the closest proximity to the sinus floor, with an average distance of 0.66 mm.
  
  
  CONCLUSIONS
  An understanding of the maxillary posterior tooth anatomy for apical resection is beneficial to the endodontist.
authors.affiliation: Practice limited to endodontics, Morgan Hill, California.
authors.forename: Sanaz A
authors.initials: SA
authors.lastname: Lavasani
authors.affiliation: Practice limited to endodontics, Bellevue, Washington.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Tyler
authors.affiliation: Division of Endodontics, University of Minnesota School of Dentistry, Minneapolis, Minnesota. Electronic address: sroach@umn.edu.
authors.forename: Samantha H
authors.initials: SH
authors.lastname: Roach
authors.affiliation: Division of Endodontics, University of Minnesota School of Dentistry, Minneapolis, Minnesota.
authors.forename: Scott B
authors.initials: SB
authors.lastname: McClanahan
authors.affiliation: Division of Oral Medicine and Diagnosis, University of Minnesota School of Dentistry, Minneapolis, Minnesota.
authors.forename: Mansur
authors.initials: M
authors.lastname: Ahmad
authors.affiliation: Division of Endodontics, University of Minnesota School of Dentistry, Minneapolis, Minnesota.
authors.forename: Walter R
authors.initials: WR
authors.lastname: Bowles
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001641:Bicuspid / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008437:Maxilla / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D008443:Maxillary Sinus / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D008866:Microsurgery / Q000379:methods*; D008875:Middle Aged; D008963:Molar / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D010159:Palate / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D019227:Tooth Apex / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D014092:Tooth Root / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D014095:Tooth, Impacted / Q000000981:diagnostic imaging / Q000601:surgery*; D055815:Young Adult
keywords: CBCT; endodontic microsurgery; maxillary posterior teeth