Root morphology and pulp chamber assessment on first and second mandibular permanent molars using cone-beam computed tomography in Peruvian individuals

ABSTRACT: Aim: The aim of this study was to evaluate the anatomical variability in the root configuration and pulp chamber of the first and second mandibular permanent molars presented on the Peruvian population with cone-beam computed tomography. Methods: This cross-sectional study included 50 cone-beam computed tomography scans (21 men and 29 women) of Peruvian individuals. A trained and calibrated investigator evaluated 100 first and 100 second mandibular molars to determine their root morphology and root canal intercommunication. The Chi-square test was analyzed to evaluate associations (P < 0.05). Results: A significant association was found between root morphology and root canal morphology. The root morphology in two fused roots presented two or three root canals (50% each), whereas the category of two separated roots has three root canals (62.9%), and the category with three separate roots presents 100% with three root canals (P < 0.001). The category of two fused roots was enclosed in 100% of intercommunications in 'C' format, whereas the condition of two or three separate roots was associated in a higher percentage in the mesiolingual distal (ML D) intercommunication, with 58.3% and 75%, respectively, (P < 0.001). Finally, the mandibular first molars mostly presented three root canals (67%), whereas the mandibular second molars presented four mandibular canals (64%), (P < 0.001). Conclusion: The root morphology of lower first and second molars presents mostly two separate roots, and when they are fused, they have two or three canals with C-shaped intercommunication, and when they are separated with two or three roots, they mostly present three canals with intercommunication ML D. Similarly, the first molars mostly have four root canals, whereas the second molars have three mandibular canals.