Objective: This cohort study aimed to assess the prevalence of anatomical variations, including radix entomolaris (RE), radix paramolaris (RP), middle mesial canal (MMC), and C-shaped canal, in the permanent mandibular first and second molars across different nationalities and genders. Materials and Methods: A total of 777 cone-beam computed tomography scans were retrospectively evaluated from patients receiving routine dental treatment at the University Dental Hospital, Sharjah, United Arab Emirates (UAE), of which 165 met the inclusion criteria. Descriptive statistics were presented as the overall number of canals and the prevalence and distribution of RE, RP, MMC, and C-shaped canals in the permanent mandibular first and second molars. Chi-square tests were performed for comparative analyses. Results: None of the mandibular first molars included had RE, RP, or MMC. No gender differences were detected. One participant (0.30%) had a C-shaped canal configuration. In mandibular second molars, the overall prevalence of C-shaped canal anatomy was 4.54%, and 0.30% for RE. A case of RE was exclusively observed in one first molar, with no instances of RP or MMC identified in our study population. Conclusion: In this study, the majority of permanent first molars exhibited two roots and four canals, while permanent second molars most frequently had two roots and three canals, with greater variations revealed in second molars and most frequently observed in Pakistani patients. A C-shaped canal configuration was more common in the second molars than in the first ones. Overall, Asian and African ethnicities tended to have significantly more canal variations than Western populations. Clinical Significance: The clinical relevance of this study lies in its potential to enhance diagnostic accuracy, treatment planning, and patient outcomes by understanding common variations and their prevalence across various ethnic groups. Therefore, clinicians can better anticipate the challenges and implications of treatment.
Dheyab et al. (Thu,) studied this question.