Prevalence of Middle Mesial Canal in Mandibular Molar Teeth Using CBCT

Introduction: Identification and completely cleaning the extra root canals are crucial for the success of endodontic treatment. Prevalence of the middle mesial canal (MMC) in mandibular molars is still a topic of debate due to the complex and diverse anatomy and morphology of these teeth. This study aimed to investigate the prevalence of MMC in mandibular molars using CBCT radiography. Methods: In this descriptive cross-sectional study, 300 CBCT images obtained between 1995 and 2019 in a private oral and maxillofacial radiology center in Yazd, Iran, were evaluated. The first and second mandibular molars were examined for the presence of MMC based on the patients' age, gender, tooth location, and type. Data were analyzed using SPSS 17 and the Chi-square. Results: Out of 300 mandibular molars (122 first molars and 178 second molars), MMC was found in only 18 teeth (6%). The prevalence of MMC was significantly higher in the first molars (18 cases) than in the second molars (0 cases). Twelve MMCs were observed in females and 6 in males. 12 MMCs were located in the left side and the rest in the right side. The mean age of individuals with MMC was 37.33±15.27. There was no statistically significant association between the presence of MMC and age, gender, or tooth location (P > 0.05), but the prevalence of MMC was higher in the first molars than in the second molars (P = 0.0001). Conclusion: The prevalence of MMC in mandibular first molars was low in the studied population and was not detected in mandibular second molars. Nevertheless, the possibility of MMC should be considered during the treatment of teeth.