Evolution of applicability of the distal tibia and calcaneus epiphysisin forensic age estimation by magnetic rezonance imaging

Aim: The first step in forensic medicine applications is identification. One of the most important stages of identification is age estimation. Nowadays, research interest on age estimation with non-radiation methods are increasing and it has started to be preferred more in practice. The aim of this study is to investigate feasibility of Vieth and Dedouit staging methods for distal tibial epiphysis and calcaneal apophysis, which were previously presented to be usable for other bone regions, by examining foot and ankle magnetic resonance images (MRI) of individuals aged 8-25 years, and to evaluate the usability of physis thickness in forensic age estimation. Materials and Methods: In our study, MRIs of 8-25 years old individuals who referred to Ankara University Faculty of Medicine Radiology Department between January 2010 and December 2022 and had ankle MRI were evaluated retrospectively. Of the 342 individuals (M: 172, F: 169) who met study criteria. Distal tibial epiphysis and calcaneal apophysis were evaluated according to Vieth and Dedouit classification. Distal tibia and calcaneal physis cartilage thicknesses were also measured. Results: According to results on distal tibia; all individuals with stage 3-4-5 according to Dedouit classification, stage 4-5-6 according to Vieth, were over 12 years old regardless of gender. It was determined that all individuals with Stage 5-6 according to Dedouit, Stage 4-5 according to Vieth were over regardless of gender, and all individuals with Stage 5 according to Dedouit and Stage 6 according to Vieth were over 18 years old in males. It was determined that all men with calcaneus stages Stage 1-2-3 according to Dedouit and Stage 2-3-4 according to Vieth are under age of 18 and women are under age of 15. The positive likelihood ratios of cut-off values determined for distal tibia were over 10 in <12 Female (OR+:18.6) and <15 Female (OR+: 34.42) groups and validity of the test was high, validity was moderate in <15 male group, and other groups were found to be sufficient. Calcaneal physis thickness was evaluated only for <12 and <15 years. The cut-off points were thinner compared to distal tibia. Similarly, men's calcaneal physis thickness was bigger than women. In <12 men, likelihood ratio was the lowest at 3.76, and it was observed that calcaneal physis thickness could be used in forensic age estimation in all groups. Conclusions: Using more than one method with a multidisciplinary evaluation in forensic age estimation minimizes the margin of error. Ankle MRI sections also appear to be useful for forensic age estimation. Significant results were obtained in the present study according to both mean age and minimum-maximum age concept. In addition, in the current study, it was demonstrated that physis thickness could be a promising technique in the evaluation of 12, 15 and 18 age limits in the analyzes to evaluate its usability in forensic age estimation by measuring the growth plate thickness. However, there is a need for prospective studies with higher sample sizes, in which socioeconomic level, height-weight, and demographic data are evaluated in more detail. Keywords: Forensic age estimation, magnetic resonance imaging, Vieth method, Dedouit method, identification.