Critical analysis of anatomy and classification of retromolar canal: an observational CBCT study

Background: The retromolar canal (RMC) is an anatomical structure of the mandibular bone located distal to the last molar. The frequency of anatomical variation in human anatomy is approximately 30-35%. This study aimed to evaluate the prevalence of the retromolar canal in a population subjected to cone beam computed tomography (CBCT). Methods: The radiographic images belonged to 200 patients (100 males and 100 females; older than 13 years old) were examined following a strict protocol. Four hundred hemi-mandibles of 100 male and 100 female patients were examined between 2019 and 2022. Results: The collected data showed 136 patients presented the RMC, bilateral in 72 cases (68%) and unilateral in the other 64 cases (32%). Gender variation did not yield statistically significant differences, with 76 male (56%) and 60 female (44%) patients affected (P>0.05). A statistically significant difference was observed for side predilection, with unilateral RMC more prevalent on the right side in 24 cases (37.5%) and on the left side in 40 cases (62.5%) (P<0.05). Conclusions: Based on the results obtained and other anatomical considerations, this study proposes a new classification for RMC.