Evaluation of the Prevalence and Morphology of Middle Mesial Canals in Bifid-Apex Mandibular Molars Using Micro-CT.

This micro-CT study analysed 90 mandibular mesial roots with and without a bifid apex. Number of orifices and main apical foramina, main canal counts at coronal/middle/apical thirds, middle mesial canal (MMC) presence, and MB-ML inter-orifice distance in two-orifice roots were measured. The prevalence of MMCs was significantly higher in bifid roots (35.5%) compared to non-bifid roots (11.4%) (p < 0.05). Bifid roots exhibited a significantly higher mean number of apical foramina (2.24 ± 0.43) than non-bifid roots (1.33 ± 0.52) (p < 0.05). In roots with two orifices, the MB-ML inter-orifice distance was significantly wider in the bifid group (2.57 ± 0.56 mm) compared to the non-bifid group (2.28 ± 0.50 mm) (p < 0.05). Canal configurations also differed significantly; bifid roots were predominantly Vertucci Type V (31.1%) and Type IV (26.7%), while non-bifid roots frequently presented with Type I (33.3%) and Type III (26.7%).