Prevalence and Morphology of the Middle Mesial Canal in the First and Second Mandibular Molars Using Cone-Beam Computed Tomography

Introduction: Understanding of the normal anatomy of the teeth as well as the anatomical variations of each tooth and between different teeth is a prerequisite for successful endodontic treatment, and errors in this area can lead to treatment failures .The aim of this study was to determine the prevalence and morphology of the middle mesial canal in the first and second mandibular molars using Cone-Beam Computed Tomography (CBCT) in the population of Isfahan City and its relationship with the distance between the orifice canals. Methods: This retrospective descriptive study examined 180 reconstructed CBCT radiographs in modified axial, coronal, and sagittal sections, and evaluated the number, location, and morphology of the canals and the spacing of the orifices. Results: 47.5% of participants had left-side first molars with three canals and 48% had right-side first molars with three canals.46.1% had a second molar on left-side with three canals and 46% had a right-side three canal second molar. 1% of participants had four canals in the left-side first molars and 1% had four canals in the right-side first molars. Conclusion: The middle mesial canal is more likely to be near the mesiobuccal and mesiolingual canals. The highest prevalence is in the right-side first molar of women and the lowest is in the left-side second molar of men. Due to the low probability of the presence of this additional canal, careful examination of the patient's molar teeth before starting endodontic treatment is recommended.