Evaluation of interorifice distance in permanent mandibular first molar with middle mesial canal in Bengaluru city, Karnataka: A cone-beam computed tomography study

Aim: Analysis of interorifice distance (IOD) between mesiobuccal and mesiolingual canals in the presence of middle mesial canal (MMC) variants in mandibular first permanent molar (MFPM) in an Indian subpopulation. To categorically assess the prevalence of MMC variants considering variation in factors of age and gender. Methods: Analysis of preoperative cone-beam computed tomography (CBCT) images was performed on 256 MFPM. MMCs were classified as fin, confluent, or independent as per the classification given by Pomeranz et al. (1981). Orthogonal slices from pulpal floor to 4 mm below were used to measure mean IOD using the CBCT software tool. Data were subjected to descriptive statistics. The Chi-square test was used for further analysis. Results: The prevalence of independent MMC was 4.7% (n = 12), confluent 14.6% (n = 37), and fin 8.7% (n = 22). The mean IOD measured for fin variant was 3.12 ± 0.512 mm, 3.31 ± 0.402 mm for confluence variant, 3.72 ± 0.493 mm for independent MMC, and 3.36 mm ± 0.579 for two-canal variant. Significant association (P = 0.001) was observed between age, gender, and overall detection of MMC, wherein the presence of fin (8.6%) and confluent (12.9%) configurations was higher (P = 0.003) in individuals ≤40 years. There was increased IOD in females (17.9%) than males (10.3%), for confluent, independent, and two-canal configuration (P = 0.04; =0.01, =0.001). Decreased IOD was observed in individuals >40 years for two-canal configurations (P = 0.05). Conclusion: Preoperative CBCT assessment of MFPM aids in the detection of MMC. According to the results of this study, individuals aged ≤40 years have shown higher prevalence of fin and confluent variants. Increased IOD was seen in females for confluent, independent, and two-canal configurations. Decreased IOD was seen in individuals aged >40 years having two-canal configuration. Thus, root canal complexities vary with age and gender, and should be taken into consideration before endodontic treatment.