Predicting MB2 Canal Morphology From Contralateral Teeth: CBCT-Based Bilateral Symmetry Analysis

Maxillary molars are prone to endodontic failure due to complex mesio-buccal canal anatomy. With increasing use of cone-beam computed tomography (CBCT), clinicians often have access to scans of homologous or contralateral teeth. This study assessed whether CBCT could predict the presence and configuration of the second mesio-buccal canal (MB2) based on bilateral symmetry. Ninety-nine CBCT scans of bilateral first and second maxillary molars were analysed. MB2 prevalence and Vertucci classification were compared among homologous, adjacent, and contralateral molars. MB2 canals were present in 96.5% of first and 81.3% of second molars. Strong correlations were found between bilateral first molars (91.9%) and bilateral second molars (78.8%), whereas agreement between adjacent or contralateral molars was lower (~60%, p < 0.05). These results indicate that CBCT scans can reliably predict the presence and configuration of the MB2 canal in bilateral maxillary molars, but this correlation does not extend to adjacent or contralateral teeth.