Accuracy of segmentation of tooth structures using 3 different CBCT machines.

Objective: The aim of this study was to evaluate the volumetric accuracy and reliability of cone beam computed tomography (CBCT)-based tooth segmentation using 4 different CBCT exposure protocols.

Methods: Two dry, intact adult human mandibles of unknown gender were scanned using 4 different CBCT exposure protocols (3 CBCT systems). The available mandibular premolars (3 per mandible) were segmented, resulting in a total of 24 segmented teeth. To assess the accuracy of the segmented teeth, volumetric and morphologic differences between the real anatomic teeth and the reconstructed images were evaluated both physically and using a high-resolution micro-computed tomography system.

Results: Results revealed a high accuracy of CBCT reconstructed images when comparing volumetric measures of CBCT-based segmented premolars to physical measurements of corresponding physical teeth. Volumetric differences were below 2%. Morphologic differences using the segmented model and the corresponding micro-computed tomography scans of the physical teeth indicated that when inaccuracies occurred, they were at the apical and coronal parts of the tooth.

Conclusion: Based on these results, CBCT can be used as a tool for segmentation and pretherapeutic planning procedures.