3D geometric analysis of second mesiobuccal canal in permanent maxillary first molar tooth

Cone-beam computed tomography scans exhibiting a second mesiobuccal (MB2) canal were examined. The vertical distance of the MB2 orifice from the pulp floor (depth), inter-orifice distance (IOD) of MB2 from mesiobuccal (MB) and palatal (P) orifices, the horizontal distance of the MB2 orifice from the line joining MB-P orifices [mesial deviation (MD)] and root canal configuration (RCC) were evaluated on 330 scans. The Student's t-test, ANOVA, Spearman's correlation and linear regression analysis were applied. The MB2 depth was 1.69 ± 0.86 mm. IOD (MB-MB2, MB2-P) was 2.18 ± 0.58 mm and 4.63 ± 1.06 mm, respectively. MD was 1.02 ± 0.37 mm. The predominant RCC was Vertucci's type II (75.5%). No correlation of depth with IOD of MB-MB2 (rho = 0.0367, p = 0.506) was observed. Significant correlation of depth with IOD of MB2-P (rho = 0.696, p < 0.001) and MD (rho = 0.174, p = 0.001) was established. No association of depth with age and IOD (MB-MB2) was observed on linear regression analysis. However, a significant positive association was established with IOD (MB2-P) (p < 0.001) and MD (p = 0.001).