Abstract
CONTEXT: Mandibular molars pose challenges in endodontic therapy because of their complex root canal anatomy, including the middle mesial canals (MMCs). Although previous studies have reported the prevalence of MMC, consistent identification remains challenging. MATERIAL AND METHODS: In an ex vivo, cross-sectional study, 200 extracted permanent mandibular first and second molars free from prior endodontic treatment were examined. Access cavity preparation and canal exploration utilized direct visual inspection and a dental operating microscope (DOM). Guided troughing was performed when MMCs were not detected along with their prevalence, length, depth, configuration, and merging patterns. RESULTS: MMCs were identified in 28.5% of first molars and 8% of second molars, with an overall prevalence of 37.5%. Average lengths were 13.49 mm for the first molars and 12.72 mm for the second molars. Confluent configurations were common and frequently merged with the mesiobuccal canal. CONCLUSIONS: This study underscores the importance of using a dental operating microscope to detect MMCs and highlights the need for thorough canal exploration to improve outcomes.