Use of non-clinical smile images for human identification: a systematic review

Abstract

Human identification using Forensic Dentistry occurs through comparative analysis of ante-mortem (AM) and post-mortem (PM) data. With the constant improvement of technology, photographs have been increasingly taken and disseminated on social media. When dental records are not available, images showing the smile can be useful tools in human identification. The aim of this study was to investigate human identification techniques through the analysis of smile images in the available literature. Studies on human identification were sought through the analysis of smile images in the scientific databases and gray literature, using pre-defined terms and keywords. Were found 4,043 studies and after screening, 14 studies were eligible, being 11 were case reports, two pilot studies and one technical note. From the eligible studies, in addition to the methodological data, information about the sample, analysis technique and its results in the human identification were extracted. Three analysis techniques were employed: direct analysis of morphological characteristics, overlapping AM and PM images, and incisal design. One or more associated techniques can be used for human identification and this analysis can be used as a unique method of identification. Authors highlighted as a limitation of the method the quality of the images, the difficulty in positioning the PM record and the peri or post-mortem modifications that may make the AM and PM comparison unfeasible. As advantages of the method, authors highlighted the analysis of smile images as a fast, accurate, and a low cost method. Thereby, studies have classified the technique satisfactorily and it application as complementary to other techniques, when there are no other AM data to be compared.