title: Analysis of facial bone wall dimensions and sagittal root position in the maxillary esthetic zone: a retrospective study using cone beam computed tomography.
abstract: OBJECTIVE
  To determine the thickness of the facial bone wall and the sagittal angulation between the long axis of the teeth and the long axis of the associated alveolar bone in the maxillary esthetic zone using cone beam computed tomography (CBCT).
  
  
  METHODS
  A retrospective radiographic study of CBCT images was conducted in 300 patients. The distance between the cementoenamel junction (CEJ) and the facial bone crest, the thickness of the facial bone wall (4 mm apical to the CEJ and midroot), and the sagittal angle between the long axis of teeth and the long axis of the respective alveolar bone were measured. Descriptive statistics and frequency analyses were performed.
  
  
  RESULTS
  The sample included 133 men and 167 women (mean age, 36.9 years; range, 18 to 60 years). The distance between the CEJ and the facial bone crest varied between 0.1 and 4 mm and showed an overall tendency to increase with age. Almost 80% of anterior teeth and 40% of premolars exhibited a thin facial bone wall (< 1 mm), and nearly 30% of sites had a bone wall thinner than 0.5 mm. The sagittal angle at approximately 80% of central incisor and second premolar sites was < 20 degrees, but the angle at more than 40% of canine sites was ≥ 30 degrees. There was a significant decrease in facial bone wall thickness from premolars to anterior teeth.
  
  
  CONCLUSIONS
  The facial bone wall in most maxillary anterior teeth was very thin. There was a substantial sagittal angulation between the long axes of teeth and those of their respective alveolar bone in most esthetic zone positions. CBCT analyses of the facial bone wall and the sagittal angle are recommended to ensure the most appropriate dental implant treatment approach.
authors.forename: Hui-ming
authors.initials: HM
authors.lastname: Wang
authors.forename: Jian-wei
authors.initials: JW
authors.lastname: Shen
authors.forename: Meng-fei
authors.initials: MF
authors.lastname: Yu
authors.forename: Xiao-yi
authors.initials: XY
authors.lastname: Chen
authors.forename: Qiao-hong
authors.initials: QH
authors.lastname: Jiang
authors.forename: Fu-ming
authors.initials: FM
authors.lastname: He
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000539:Alveolar Process / Q000000981:diagnostic imaging*; D001641:Bicuspid / Q000000981:diagnostic imaging; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D003481:Cuspid / Q000000981:diagnostic imaging*; D004955:Esthetics, Dental; D005260:Female; D006801:Humans; D007180:Incisor / Q000000981:diagnostic imaging*; D008297:Male; D008437:Maxilla / Q000000981:diagnostic imaging*; D008875:Middle Aged; D012189:Retrospective Studies; D019237:Tooth Cervix / Q000000981:diagnostic imaging; D014092:Tooth Root / Q000000981:diagnostic imaging*; D055815:Young Adult