Prevalence of Middle Mesial Canals and Isthmi in the Mesial Root of Mandibular Molars: A Retrospective Cone-Beam Computed Tomographic Study.

Objective: To know the prevalence of a true middle mesial canal and isthmus in the mesial root of lower first and second molar teeth using cone beam computed tomography (CBCT) in an Indian population. Material and Methods: Two hundred fifty-six mandibular first and second molar teeth were evaluated from CBCT scans of 220 patients. Age, gender, presence of isthmuses and middle mesial canalsand number of root canals in the mesial root were doc- umented. Results: Of the 256 teeth studied, 38 (14.8%) of teeth were having true middle mesial canals. The prevalence of the middle mesial canal was 28% in first molar teeth and 7% in second molar teeth and the occurrence among the two teeth was statistical- ly non-significant (P = 0.83). No statistical difference was foundbetween the presence of middle mesial canal and age and gender. The frequency of isthmi in the mesial roots was 69.63% and the prevalence of isthmi was significant in patients between 20 to 30 years of age (P < 0.001). Conclusion: This study showed an increased rate of lower molar teeth with middle mesial canals or isthmi. [ABSTRACT FROM AUTHOR]