Cone-Beam computed tomography assessment of root canal morphology and the relationship of maxillary first molars with adjacent anatomical structures in a Vietnamese sub-population

Abstract

Background: Dental treatment of the maxillary first molar is often challenging due to its complex anatomical configuration and the close proximity of its roots to the maxillary sinus. Objective: This study investigated the root canal morphology and the spatial relationship between the maxillary first molar roots and the maxillary sinus floor using cone-beam computed tomography (CBCT). Materials and methods: A retrospective cross-sectional study analyzing 459 maxillary first molars from 255 CBCT images across axial, coronal, and sagittal planes was conducted. Parameters assessed included the number of roots and canals, canal configurations according to the Vertucci classification, the spatial relationship between canal orifices, and the distance from the root apices to the maxillary sinus floor. Results: 100% of maxillary first molars possessed three roots and 56.9% exhibited second mesiobuccal canal. The MB root canal showed significant morphological diversity, with Vertucci Type I (43.1%) being the most prevalent configuration. Regarding spatial orientation, 78.2% of the second mesiobuccal orifices were located mesially relative to the line connecting the first mesiobuccal and palatal orifices. The mean distance between the two mesiobuccal canal orifices was 2.00 ± 0.34 mm, with a statistically significant difference observed between genders. A substantial proportion of roots exhibited Type III (contact) and Type IV (protrusion) sinus-root relationships, particularly in the younger age groups (≤ 20 and 21-30 years). Increased age was significantly associated with a greater distance to the sinus floor and the sinus-root distance was smaller in females compared to males across all roots. Conclusion: Maxillary first molars demonstrate a high prevalence of a second mesiobuccal canal and an intimate anatomical relationship with the maxillary sinus floor. These findings underscore the necessity of CBCT as an essential diagnostic tool in complex endodontic and oral surgical procedures in the posterior maxilla, crucial for accurate canal localization, precise treatment planning, and minimizing the risk of sinus-related complications.