Evaluation of root and root canal morphology in maxillary first molar teeth: A cone-beam computed tomography study using two classification systems in a Japanese population.

Background/purpose: Inadequate understanding of tooth morphology can lead to missing root canals and procedural errors during root canal treatment. This study assessed the root and root canal morphology of maxillary first molars in a Japanese population, employing two classification systems and utilizing cone-beam computed tomography (CBCT).

Materials And Methods: The study included CBCT scans of 833 maxillary first molars from 642 Japanese individuals aged 16-80 years. The evaluations used the Vertucci and Ahmed classification systems to assess root and root canal morphologies and fusions. Data were statistically analyzed based on gender and age using the chi-square test ( < 0.05).

Results: Ninety-seven percent of maxillary first molars had three separate roots. The second mesiobuccal canal (MB2) was identified in 52.9 % of teeth. Six root types and 17 tooth types were identified with the Vertucci and Ahmed classifications, respectively. The most common configuration of the mesiobuccal root having the MB2 was Vertucci type IV (31.2 %) followed by type II (15.3 %). A higher occurrence of MB2 was noted among males (58.9 %) and individuals in their 21-40 years (56.8 %) ( < 0.05). Root fusion, root canal fusion, and C-shaped root canals, which were unclassifiable by the Vertucci classification, were identified in 2.8 %, 0.9 %, and 0.7 %, respectively.

Conclusion: Maxillary first molar in the Japanese population displayed notable anatomical variations, underscoring the importance of recognizing age- and gender-related anatomical characteristics. The Ahmed classification offered a more detailed depiction of morphological diversities, enhancing the understanding and treatment of complex root canal systems.