The Prevalence of Second Distal Canals in the Mandibular First Molars: A Histological and Cone Beam Computed Tomography Study.

Abstract

Purpose: The prevalence of the Second Distal Canal (SDC) in the Mandibular First Molar (MFM) was assessed using histological and Cone Beam Computed Tomography (CBCT) studies. Materials and Methods: This study included a total of 348 extracted MFM, which were divided into 6 groups according to gender and age. All the teeth were viewed by one CBCT device, and then the teeth were histologically examined. The images were evaluated, and the obtained results were analyzed by SPSS software using the Chi-square test. The comparison was considered statistically significant at p<0.05. Results: The prevalence rate of the canals was 171 (49.13%), males and females were 89 and 82, respectively, and according to the level of sectioning, they were found to be 43.94% of all the sections, with the lowest 16.11% and 15.62% at level 5 (coronal level) and level 1 (apical level) when viewed only histologically, being 110, while when viewed histologically and by CBCT, there were 61 teeth for the SDC, respectively, which was more in younger than older patients with no statistically significant difference. Conclusion: The prevalence rate of the SDC seen by CBCT was 17.32%, while histologically it was 49.13%, respectively. Clinically, many canals cannot be detected because of their small size, which cannot be seen radiographically.