(PO109) A CBCT Analysis of Mid-Mesial Canal Morphology in Mandibular First Molars

Abstract: In recent literature, the prevalence of the mid-mesial canal in mandibular first molars has become an important topic of research, with the reported incidence of the canal being present ranging from 0.26% to 46.15%. The purpose of this study was to evaluate the occurrence of mid-mesial (MM) canals in mandibular first molars, whether they are more common in teeth with 2 distal canals, as well as the relationship of inter-canal distances with and without the presence of the mid-mesial. One hundred images were acquired with Veraview X800 Morita CBCT (pixel size = 80 μm) and evaluated according to Vertucci’s classification. Two independent evaluators (oral and maxillofacial radiology and endodontic residents) evaluated the distance between the center points of the mesial canals and distal canals. Comparisons between groups were made using Student’s t-test, and relationships between parameters were assessed by Pearson’s correlation coefficient (p < .01). The MM canal was present in 10 cases (10%) reviewed during this study. The average distance between the mesial-buccal (MB) canals and the mesial-lingual (ML) was greater for teeth with MM present; however, it was not statistically significant. The distance from mesial canals to distal canals was also greater in the MM group but not statistically significant. Of the teeth with an MM canal present, the majority (90%) were Vertucci class 2 or 3, joining either the MB or ML canal before the apical exit. In conclusion, a greater inter-canal distance in mandibular molars may suggest the presence of a third mesial canal (mid-mesial).