Applicability of the mandibular canine index for sex estimation: a systematic review

Background: The Mandibular Canine Index (MCI) comprises a method of sex estimation by teeth that presents controversial results in the literature. Main body: This systematic review aims to expose whether MCI can be used as a method of reliable sex estimation. A literature search was performed using the keywords “canine,” “sex,” “gender,” “determination,” “estimation,” “dimorphism,” “assessment,” “forensic” in the databases Pubmed, Scopus, Lilacs, Scielo, and Web of Science. In addition, manual searches were carried out on the reference lists of the selected articles to cover the largest number of articles of interest as possible. Studies that performed the measurements only on maxillary canines, scientific conferences abstract books, case reports and literature reviews were excluded. The assessment of methodological quality and risk of bias was carried out based on a checklist for cross-sectional studies and another for accuracy studies. Thus, 53 articles were selected, 13 of which were accurate and 40 were cross-sectional. All accuracy articles were assessed as low risk. Among cross-sectional articles, seven were considered to be of low risk, 31 of moderate risk, and two of high risk. The accuracy of the sex estimate by MCI was verified and, despite varying among studies, the minimum and maximum values found were, respectively, 20% and 87.5% for women and 40.6% and 94% for men. Conclusion: The accuracy of the MCI was variable and should be used with caution and as an auxiliary method of sex estimation.