Accuracy of assessing the mandibular canal on cone-beam computed tomography: a validation study.

Purpose: To establish the accuracy of cone-beam computed tomographic (CBCT) views in determining the position and diameter of the mandibular canal.

Materials And Methods: Two freshly frozen cadaver heads, 1 dentate and 1 edentate, were used to acquire CBCT scans. Measurements on cross-sectional CBCT images were compared with measurements on digitized histologic sections of the same regions in the mandibles. The Student t test was used for statistical analysis.

Results: Comparing CBCT with histologic measurements showed that the position of the mandibular canal differed up to 0.47 mm (standard deviation, 0.29 mm). Mandibular canal diameters were up to 22.8% smaller in the CBCT planes. For the dentate jaw, these differences were statistically significant.

Conclusion: To be safe, when assessing the mandibular canal position on CBCT views, a 0.76-mm deviation should be taken into account. Because the diameter of the mandibular canal is displayed smaller, an enlargement by 0.74 mm is recommended.