Prevalence of The Second Mesio-buccal Canal and Second Distobuccal Canal in The Maxillary First Molars Among a Sample of Erbil –Kurdistan Region Population Using CBCT

Background and Objectives: Adequate knowledge of anatomic variations in root canal morphology is essential for improving the outcome of root canal treatment. The maxillary first molars commonly require endodontic treatment; however, they are known to have the most complex root canal systems. Aim: To evaluate the frequency of the second mesiobuccal (MB2) canal and the second distobuccal (DB2) canal in maxillary first molars, as well as the bilateral symmetry of the maxillary first molars (MFM) with the second mesiobuccal canal, and the association of gender and age to their occurrence using cone beam computed tomography (CBCT). Methods: This retrospective study investigated 140 maxillary first molars from 80 CBCT scans collected from a private dental imaging centre in Hawler over 4 months from May to August 2024. The patients were aged 13 to 57 years (mean age: 29.1 years). Data were analysed using SPSS (version 25) with descriptive statistics and the Chi-Square test. Results: The prevalence of the MB2 canal in MFM was 53.6%. Both males and females have a similar prevalence of MB2 canals in their MFM. In 75 MFM with MB2 canals, a single apical exit was found in 51.9% of the cases. No significant correlation was found between the prevalence of the MB2 canal and gender or age. In the 41 patients with MB2 canals in their MFM, the likelihood of bilateral MB2 canals was high (82.9%). The frequency distribution of the second distobuccal canal was low (7.9%); however, the age group 21-30 showed the highest occurrence of second distobuccal canals in MFM. Conclusion: The use of CBCT is a valuable tool in detecting MB2 canals, therefore improving the outcomes of root canal treatment. A high prevalence of MB2 canals was found in the study. The prevalence of bilateral MB2 was high. Keywords: Cone Beam Computed Tomography (CBCT), Maxillary first molar, MB2, Root canal system, Distobuccal canal.