Revista Portuguesa de Estomatologia, Medicina Dentária e Cirurgia Maxilofacial Review Article Prevalence of root canal system configurations in the brazilian population analyzed by cone-beam computed tomography – a systematic review Emmanuel João Nogueira Leal Silva a,b, *, Marina Carvalho Prado b , Marco Antonio Hungaro Duarte c , Marco A. Versiani d , Duarte Marques e,f ,g , Jorge N.R. Martins e,f a Department of Endodontics, School of Dentistry, Grande Rio University, Rio de Janeiro, Brazil. b Department of Endodontics, Rio de Janeiro State University, Rio de Janeiro, Brazil c Department of Endodontics, School of Dentistry, Universidade de São Paulo (USP), Bauru, Brazil. d Dental Specialty Center, Brazilian Military Police, Minas Gerais, Brazil e Centro de Estudo de Medicina Dentária Baseada na Evidência, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal f Instituto de Implantologia, Lisbon, Portugal g LIBPhys-FCT UID/FIS/04559/2013, Lisbon, Portugal a b s t r a c t a r t i c l e i n f o Article history: Received 7 May 2020 Accepted 20 February 2021 Available online xx March 2021 Objectives: This study performed a systematic review of anatomy prevalence studies using cone-beam computed tomography to comprehend the root and root canal configuration types in Brazilian sub-populations. Methods: This systematic review followed PRISMA’s statements. Four electronic databases (PubMed, ScienceDirect, Lilacs, and Cochrane Collaboration) were accessed using MeSH ter- ms and free-text keywords. The studies were selected according to predefined criteria. Re- ferences of the collected studies, three peer-reviewed endodontic journals, and two peer-re- viewed evidence-based dentistry journals were hand searched. The authors were contacted for additional information, if necessary. Eligible studies were submitted to a scientific merit assessment by two evaluators independently, who reached a final consensus for each study score using the Joanna Briggs Institute Critical Appraisal tool for prevalence studies. Results: A total of 2266 studies were identified. After analysis, 20 full-text articles were ac- cessed for eligibility and 17 were included for qualitative synthesis. A high prevalence of mandibular incisors presenting two root canals was noted (~35.0% – 40.0). Moreover, a high proportion of two-rooted (17.0% – 28.4%) and two root canals (50.1% – 75.0%) morphologies were identified in maxillary second premolars. A wide range and a high percentage of a second mesiobuccal canal were detected for both maxillary first (37.1% – 88.5%) and second molars (21.8% – 83.4%). A second root canal prevalence ranging from 12.4% to 23.4% was observed in the distal root of mandibular first molars. Keywords: Anatomy Brazil Cone-beam computed tomography Prevalence Root canal therapy Systematic review * Corresponding author. E-mail address: nogueiraemmanuel@hotmail.com (Emmanuel João Nogueira Leal Silva). http://doi.org/10.24873/j.rpemd.2021.03.829 1646-2890/© 2021 Sociedade Portuguesa de Estomatologia e Medicina Dentária. Published by SPEMD. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). rev port estomatol med dent cir maxilofac. 2021; 62(1) : xxx-xxx ARTICLE IN PRESS