title: Accuracy of alveolar bone measurements from cone beam computed tomography acquired using varying settings.
abstract: OBJECTIVE
  To investigate the accuracy and reliability of cone beam computed tomography (CBCT) measurements of buccal alveolar bone height (BBH) and thickness (BBT) using custom acquisition settings.
  
  
  METHODS
  School of Dentistry, Oregon Health & Science University. Twelve embalmed cadavers.
  
  
  METHODS
  Cadaver heads were imaged by CBCT (i-CAT® 17-19, Imaging Sciences International, Hatfield, PA) using a 'long scan' (LS) setting with 619 projection images, 360° revolution, 26.9 s duration, and 0.2 mm voxel size, and using a 'short scan' (SS) setting with 169 projection images, 180° rotation, 4.8 s duration, and 0.3 mm voxel size. BBH and BBT were measured with 65 teeth, indirectly from CBCT images and directly through dissection. Comparisons were assessed using paired t-tests (p≤0.05). Level of agreement was assessed by concordance correlation coefficients, Pearson's correlation coefficients, and Bland-Altman plots.
  
  
  RESULTS
  Mean differences in measurements compared to direct measurements were as follows, LS 0.17±0.12 (BBH) and 0.10±0.07 mm (BBT), and SS 0.41±0.32 (BBH) and 0.12±0.11 mm (BBT). No statistical differences were found with any of BBH or BBT measurements. Correlation coefficients and Bland-Altman plots showed agreement was high between direct and indirect measurement methods, although agreement was stronger for measurements of BBH than BBT.
  
  
  CONCLUSIONS
  Compared to the LS, the similarity in results with the reduced scan times and hence reduced effective radiation dose, favors use of shorter scans, unless other purposes for higher resolution imaging can be defined.
authors: Private Practice in Orthodontics, Garland, TX, USA.
authors: V C
authors: VC
authors: Cook
authors: A M
authors: AM
authors: Timock
authors: J J
authors: JJ
authors: Crowe
authors: M
authors: M
authors: Wang
authors: D A
authors: DA
authors: Covell
mesh_terms: D000368:Aged; D000539:Alveolar Process / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D002102:Cadaver; D002508:Cephalometry / Q000706:statistics & numerical data*; D054893:Cone-Beam Computed Tomography / Q000379:methods / Q000706:statistics & numerical data*; D061827:Dimensional Measurement Accuracy; D004210:Dissection / Q000379:methods; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods / Q000706:statistics & numerical data; D008297:Male; D015203:Reproducibility of Results; D012399:Rotation; D013997:Time Factors
keywords: alveolar bone height; cone beam computed tomography; orthodontics; reliability of results