Prevalence of second mesiobuccal canal in maxillary first and second molar detected using cone-beam computed...

A thorough understanding of root canal morphology, particularly the second mesiobuccal (MB2) canal, is crucial for successful endodontic treatment of maxillary molars. The prevalence of MB2 shows ethnic variability, and this systematic review and meta-analysis aimed to synthesize existing CBCT-based studies to determine the prevalence of the second mesiobuccal canal (MB2) in the Han population.

A systematic review and meta-analysis were conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Databases including PubMed, MEDLINE, Scopus, and ClinicalKey were searched through 17th August 2025. Studies reporting MB2 prevalence in permanent maxillary first and/or second molars within Han populations using CBCT were included. Data were pooled using a random-effects model.

Fourteen eligible studies involving 15,639 participants and 35,929 teeth were analyzed. The pooled MB2 prevalence was 63.7 % for permanent maxillary first molars (PMFMs) and 23.3 % for permanent maxillary second molars (PMSMs). Males had significantly higher odds of having MB2 canals in both molar types (Odds Ratio = 1.532 and 1.790, respectively). No significant difference was found between left and right sides. Heterogeneity was high (I ² > 95 %), but most studies were of high methodological quality.

MB2 canals are common in the Han population, particularly in PMFMs. Clinicians may consider advanced imaging like CBCT to improve detection and treatment outcomes. Sex-related differences further underscore the need for individualized diagnostic approaches.