Prevalence of the second mesiobuccal canal of maxillary molars in the South American population: a systematic review and meta-analysis of CBCT studies
Abstract
Background: The objective of this systematic review and meta-analysis was to determine the prevalence of the second mesiobuccal (MB2) canal in permanent maxillary molars within the South American population, evaluated exclusively through cone-beam computed tomography (CBCT).
Methods: Following the PRISMA guidelines, an electronic search was conducted across PubMed, Scopus, Web of Science, Embase, SciELO, LILACS, and gray literature until May 2026. Observational studies published from 1990 onwards were included. A meta-analysis of proportions was executed using a random-effects model. The risk of bias was assessed with the JBI tool, and the certainty of evidence using the GRADE framework.
Results: A total of 23 observational studies were included. The pooled overall prevalence of the MB2 canal was 59% (95% CI: 53%-66%). In the tooth-specific analysis, prevalence reached 66% in first molars and 41% in second molars. Significant sexual dimorphism was evident in second molars, where males presented a 35% higher probability of possessing the canal (OR = 1.35). The GRADE analysis indicated a High certainty for the overall and first molar prevalences, and Moderate for second molars.
Conclusions: The MB2 canal is a highly prevalent anatomical variation in South America, constituting the anatomical norm in first molars. The clinical use of CBCT is crucial for its diagnostic prediction and successful management.
Systematic review registration: DOI: 10.17605/OSF.IO/KRG4Z.
How strong is the evidence?
Evidence Hub reads this as a meta-analysis. Its evidence level is 1 of 5 (Highest · pooled evidence). Pooled evidence from several studies sits at the top of the evidence pyramid.
Read the paper
Related studies
- Understanding the factors influencing fall armyworm (Spodoptera frugiperda J.E. Smith) damage in African smallholder maize fields and quantifying its impact on yield. A case study in Eastern Zimbabwe
- Alarming situation of emerging H5 and H7 avian influenza and effective control strategies
- Livestock and food security: vulnerability to population growth and climate change
- Atmosphere–ocean oxygen and productivity dynamics during early animal radiations
- Characterization of the global distribution and diversified plasmid reservoirs of the colistin resistance gene mcr-9
- The global seroprevalence of Toxoplasma gondii in pigs: A systematic review and meta-analysis
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.