Abstract

Introduction: The anatomical variability in root canal systems of permanent molars presents significant challenges for endodontic treatment, which still need to be explored. Objective: To synthesize scientific evidence on geographical variations in the number of root canals in permanent molars. Material and Methods: A systematic review was conducted at the University of Medical Sciences of Havana, analyzing the number of root canals in permanent molars. Primary studies in English, Spanish, and Portuguese were included, focusing on the anatomical details of root canals. Clinical case studies, editorials, and studies without specific root canal information were excluded. We searched PubMed, Scopus, and Web of Science for relevant studies published from 1971 to 2023. Sensitivity analysis assessed the impact of methodological quality on the results. Findings were synthesized by geographical region, describing the prevalence of different root canal configurations. Results: Data from 93 studies encompassing 60,402 molars were analyzed. Significant geographical variations in root canal anatomy were observed. In Africa, first and second upper molars typically had three root canals (45.62% and 41.31%), as did first and second lower molars (59.79% and 67.55%). In America, upper first molars predominantly had four root canals (56.66%). In Asia, most molars had three root canals, except for lower third molars which commonly had two or three canals (42.88% and 57.12%). In Europe, molars generally had three root canals, except for lower third molars which lacked specific data. In Oceania, upper first molars frequently had six root canals (65%). Conclusions: Significant geographical variations in root canal anatomy of permanent molars were observed, with distinct patterns among different continents. These findings call for standardized, comprehensive research, particularly in underrepresented areas and on third molars, to better inform clinical practice and add to global understanding of molar anatomy. Clinical significance: Understanding regional root canal variations improves endodontic treatment planning and accuracy. Thus, this knowledge is fundamental for adapting techniques and should inform dental education. © 2025, Universidad de Concepcion. All rights reserved.