Accuracy of alveolar bone measurements from cone beam computed tomography acquired using varying settings

• Published in: Orthodontics & craniofacial research Vol. 18; no. S1; pp. 127 - 136
• Main Authors: Cook, V. C., Timock, A. M., Crowe, J. J., Wang, M., Covell Jr, D. A.
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01-04-2015; Wiley Subscription Services, Inc
• Subjects: Accuracy; Aged; Agreements; alveolar bone height; Alveolar Process - anatomy & histology; Alveolar Process - diagnostic imaging; Cadaver; Cephalometry - statistics & numerical data; cone beam computed tomography; Cone-Beam Computed Tomography - methods; Cone-Beam Computed Tomography - statistics & numerical data; Dimensional Measurement Accuracy; Dissection - methods; Female; Humans; Image Processing, Computer-Assisted - methods; Image Processing, Computer-Assisted - statistics & numerical data; Male; orthodontics; reliability of results; Reproducibility of Results; Rotation; Time Factors; Tomography; reliability of results; orthodontics; alveolar bone height; cone beam computed tomography
• ISSN: 1601-6335; 1601-6343
• DOI: 10.1111/ocr.12072

Structured
Objectives
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.
Settings and Sample Population
School of Dentistry, Oregon Health & Science University. Twelve embalmed cadavers.
Materials and 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.