Root Form and Root Canal Configuration of Permanent Maxillary First Molars in the Meerut Population: An In Vivo Cone-Beam Computed Tomography Study.

Background Endodontic success in maxillary first molars depends on accurate knowledge of root and canal morphology, particularly the frequently complex mesiobuccal (MB) root, which often harbors an additional MB2 canal. Population-specific variations necessitate region-focused studies using advanced imaging techniques such as cone-beam computed tomography (CBCT). The aim of this in vivo CBCT study was to evaluate the root form and root canal configuration of permanent maxillary first molars in the Meerut population, with the primary objective of determining the prevalence of the MB2 canal and accessory canals in other roots and to classify morphologies using both the Vertucci and Ahmed systems. The secondary objectives included assessing sex-based differences and generating region-specific anatomical data to enhance preoperative planning and treatment outcomes. Methodology This prospective observational study included 300 permanent maxillary first molars from CBCT scans of individuals aged 18-70 years acquired for various clinical indications. The scans were evaluated using multiplanar reconstruction (voxel size ≤0.2 mm). Root number, canal number, and configuration were classified according to Vertucci's system; non-fitting morphologies were further described using Ahmed's (orifice-canal-foramen (O-C-F) coding. Inter and intraobserver reliabilities were confirmed (κ > 0.85). Data were analyzed descriptively using inferential statistics (chi-square, Cohen's kappa, and correspondence analysis, with p-values <0.05 considered significant). Results A total of 300 participants (300 maxillary first molars) were included in the study. The MB root showed the highest anatomical complexity, with approximately 180 (60%) cases demonstrating MB2-related configurations, predominantly Vertucci Types II and IV. In contrast, the distobuccal and palatal roots exhibited simple canal morphology, with over 282 (>94%) cases presenting Type I configurations. Ahmed's classification system successfully categorized all 300 (100%) cases, including 15 (5%) MB roots that were unclassifiable under Vertucci's system, and showed almost perfect to perfect agreement (κ = 0.96-1.00). No statistically significant differences were observed between male and female participants in terms of root or canal configuration distribution. Conclusions The MB root of the maxillary first molars in the Meerut population displayed substantial anatomical variability, with a high prevalence of MB2 canals. The Ahmed classification offered superior descriptive details and eliminated unclassifiable cases compared to the Vertucci classification. These findings underscore the need for heightened vigilance, preoperative CBCT evaluation when indicated, and enhanced detection techniques to improve endodontic predictability in northern Indian populations.