Root canal anatomy of human permanent mandibular incisors and mandibular canines: A systematic review

Mandibular incisors and canines show variations in their root canal anatomy. It is imperative to be aware of these variations to lower the frequency of missed canals. The objective was to systematically review the existing studies to recognize the root and root canal anatomy of the mandibular incisors and canines among the population of various geographical locations, as studied by different methods. This systematic review was registered in the International Prospective Register of Systematic Reviews database under the number CRD42020185146. An exhaustive search was undertaken in three electronic databases – MEDLINE PubMed, EBSCOhost, and Google Scholar – along with hand-searching for the identification of studies. Studies were selected following strict inclusion and exclusion criteria. Selected studies were scored using the Joanna Briggs Institute Critical Appraisal tool for prevalence studies to determine the risk of bias. This review included data from 26 countries including the analysis of 71,404 mandibular anterior teeth. The risk of bias of all included studies was either low or moderate. Overall, it was seen that the percentage of second canals was higher in lateral than in central incisors. Mandibular canines occasionally showed the presence of two roots. Deviations in anatomy were high in the Middle Eastern European countries and the Indian subcontinent. Limitations are as follows: lack of homogeneity across data reported in the studies concerning the methods used to study the root canal anatomy. Diversities seen in the root canal configurations of mandibular incisors and canines vary according to ethnicity, and thus, one must have a thorough knowledge before commencing endodontic treatment.