Cone-beam computed tomography and microtomography for alveolar bone measurements

To compare cone-beam computed tomography (CBCT) and microtomography (micro-CT) for alveolar bone measurements.

Forty teeth and alveolar bone blocks of five pigs were scanned on a micro-CT with a 9.05 μm pixel size, and on a CBCT device at 0.125 mm voxel size. One height and four thickness measurements were performed twice in standardized slices by two radiologists to verify reliability. Agreement between imaging methods was assessed by correlation coefficients, Bland-Altman plots, and the difference was tested by a Wilcoxon signed-rank test.

Regarding intra- and interobserver agreements, all bone measurements presented excellent precision values for micro-CT, but interobserver agreement for CBCT presented good to moderate values. Bone height differed about 0.3 mm, but no statistically significant differences were found for the bone thickness measurements.

CBCT underestimated bone height. No statistically significant differences were found for bone thickness. Regions of thin bone tissue may not be visualized on CBCT images. There are risks of underestimating bone measurements with CBCT and assuming bone loss that does not exist clinically. Although the difference of the bone height measurement was small, the clinical relevance must be analyzed on how to interpret CBCT.