Accuracy and Reliability of Buccal Bone Height and Thickness Measurements from Cone-beam Computed Tomography Imaging

Introduction: Cone-beam computed tomography (CBCT) imaging has broadened opportunities for examining morphologic aspects of the craniofacial complex, including alveolar bone, but limitations of the technology have yet to be defined. Through the use of comparisons with direct measurements, the purpose of this study was to investigate the accuracy and reliability of buccal alveolar bone height and thickness measurements derived from CBCT images.

Methods: Twelve embalmed cadaver heads (5 female, 7 male; mean age: 77 years) were scanned with an i-CAT 17-19 unit (Imaging Sciences International, Hatfield, Pa) at 0.3 mm voxel size. Buccal alveolar bone height and thickness measurements of 65 teeth were made in standardized radiographic slices and compared with direct measurements made by dissection. All measurements were repeated 3 times by 2 independent raters and examined for intrarater and interrater reliability. Measurement means were compared with 2-tailed t tests. Agreement between direct and CBCT measurements was assessed by concordance correlation coefficients, Pearson correlation coefficients, and Bland-Altman plots.

Results: Intrarater reliability was high as were interrater correlations for all measurements (≥0.97) except CBCT buccal bone thickness (0.90). CBCT measurements did not differ significantly from direct measurements, and there was no pattern of underestimation or overestimation. The mean absolute differences were 0.30 mm in buccal bone height and 0.13 mm in buccal bone thickness with 95% limits of agreement of -0.77 to 0.81 mm, and -0.32 to 0.38 mm, respectively. Agreement between the 2 methods was higher for the measurements of buccal bone height than buccal bone thickness, as demonstrated by concordance correlation coefficients of 0.98 and 0.86, respectively.

Conclusions: For the protocol used in this study, CBCT can be used to quantitatively assess buccal bone height and buccal bone thickness with high precision and accuracy. Comparing the 2 sets of CBCT measurements, buccal bone height had greater reliability and agreement with direct measurements than did the buccal bone thickness measurements.