Purpose: This study assessed the effects of cone-beam computed tomography (CBCT) voxel size and exposure settings on the accuracy of alveolar bone thickness (BT) measurements. Materials and Methods: Seven pig mandibles were scanned using 6 CBCT settings: 200, 400, and 600 μm voxels,each with an ultra-low dose (ULD) and a standard dose (SD) setting. BT was measured at 3 locations on 1 anterior and 1 posterior tooth. These teeth were then scanned using micro-computed tomography (micro-CT), and BT was measured at the same locations. The intraclass correlation coefficient (ICC) and paired t-test were used to evaluate agreement between CBCT and micro-CT measurements. The discrepancy between CBCT and micro-CT measurements was calculated, and repeated-measures analysis of variance (RMANOVA) was used to evaluate the effects of the 6 CBCT settings on BT measurement accuracy. Results: The lowest discrepancy between micro-CT and CBCT was observed with the 600 μm ULD (0.29±0.39 mm), followed by the 200 μm SD (0.41±0.72 mm). When BT was less than 2 mm, the lowest discrepancy occurred with the 200 μm SD (0.29±0.33 mm), followed by the 600 μm ULD (0.32±0.25 mm). The ICC between CBCT and micro-CTdecreased as BT decreased. RMANOVA indicated no significant effect of CBCT settings on measurement accuracy. Conclusion BT measured with the 600 μm ULD was comparable to that obtained with the 200 μm SD. Thediscrepancy between CBCT and micro-CT was notable, especially when BT was less than 2 mm.

The canalis sinuosus (CS) and its accessory canals (ACs) are anatomical structures in the anterior maxilla. These structures are often neglected when planning implant surgery because their clinical significance is still not well-defined. After a retrospective evaluation of 194 patients rehabilitated with dental implants in the anterior maxilla, 3 patients were identified who presented unexpected chronic neurosensory disturbances without any clinical signs supportive of implant failure. Tomographic assessment using cone-beam computed tomography (CBCT) revealed the invasion of the CS and ACs by dental implants, which appeared to explain the patients’ symptoms. The purpose of this report was to familiarize practicing dentists and specialists with the CS and its ACs. Unanticipated neurosensory symptoms after implant placement in the anterior maxilla justify the use of CBCT to rule out an injury to this neurovascular bundle.