Dental DNA as an Indicator of Post-Mortem Interval (PMI): A Pilot Research

Abstract

Teeth have proven to be a reliable source of DNA for forensic analysis as the pulp is rich in cells and protected from damaging factors and contamination by dental hard tissues. The pilot study aims to evaluate the feasibility of Next-Generation sequencing analysis on dental pulp to detect genetic mutations in DNA caused by post-mortem cell necrosis. We used a 56-gene oncopanel kit on a sample of 17 teeth extracted from living patients. Time of the tooth avulsion was assumed as death of the individual and Post-mortem Interval (PMI) was the time elapse since the DNA extraction and analysis. Days and Accumulated Degree Days (ADD) were assumed as measures of PMI that ranged between 0 to 34 days. Only 38 of the 56 considered genes proved to be affected by mutations (101), thus being of forensic interest. More specifically, 14 mutations occurred only in a specific range of PMIs/ADD; 67 were detected (alone or as clusters of the same gene) at specific PMI/ADD; 22 occurred at every PMI/ADD, except for some specific intervals. Since dental pulp was not targeted by any oncological diseases and all teeth were intact, vital, and from patients with unremarkable medical history, it could be assumed that mutations were due to post-mortem DNA changes induced by pulp death and the increasing time elapse since death. This pilot study found encouraging results in the application of NGS analysis on dental DNA, especially for PMIs of several days for which the traditional tools for PMI estimation have limitations. Further research on a larger sample of PMI and validation research on a larger sample of PMI and validation of the results are indeed necessary.

A Semi-Automatic Method on a Small Italian Sample for Estimating Sex Based on the Shape of the Crown of the Maxillary Posterior Teeth

“…Teeth are excellent substrates for research in many forensic fields since they are mineralized tissues characterized by a high resistance to environmental factors [ 38 ]. They are well-known as valuable sources of evidence in the identification process, both as primary identifiers for unknown dead bodies [ 39 ] and contributing to the estimation of the biological profile of human remains [ 40 ].…”

Catch me if you can—emission patterns of human bodies in relation to postmortem changes

“…In addition to the detection of human corpses and remains, the determination of the time since death is another possible application of chemical profiles of different stages of decomposition [ 44 ]. Although intensive research has been conducted for more than a century to determine the post-mortem interval [ 45 ], in the earlier past with new approaches concerning changes in biochemical constituents in different body tissues or body fluids [ 46 , 47 ], DNA/RNA degradation [ 48 , 49 ] or the post-mortem microbiome [ 50 ], this topic remains challenging. So far, entomology is the only proven and accepted tool for estimating a minimum period in the late interval and there is the need for more methods [ 44 , 51 ].…”

Estimativa do intervalo post mortem mínimo em situações forenses por meio da análise histológica dos dentes

“…Métodos bioquímicos consistem, principalmente, na quantificação de material genético (BORGES, et al, 2021;BIANCHI et al, 2022), análise proteômica (PROCOPIO et al, 2018) e datação por radiocarbono (CATTANEO, 2007;SZELECZ et al, 2018;WU, 2020;CAPPELA et al, 2015). YADAV et al, 2015).…”