Human identification through DNA analysis of restored postmortem teeth

The identification of human remains using DNA analysis can be extremely challenging and its success is certainly influenced by the time elapsed since death. In that context, intact teeth have been shown to be highly successful in DNA analysis. However, restored teeth are usually available and, surprisingly, these specimens have been poorly studied. In fact, there are no reports regarding forensic DNA analysis of those types of samples in real cases. Therefore, the aim of this study was to perform DNA typing on healthy and restored teeth from exhumed human remains, which had been buried for 46 years. A powder-free DNA extraction protocol specifically designed for teeth was followed and human DNA quantitation and degradation assessment was performed using an in-house qPCR assay. Samples were amplified with commercial human identification kits for autosomal and Y chromosome markers. The obtained DNA profiles were compared to those of a previously processed femur sample as well as a buccal swab from a putative son. One healthy and one restored tooth yielded complete, concordant and compatible DNA profiles with previously typed samples from the femur and the putative son. Biostatistical calculations supported the paternity relationship with a likelihood ratio greater than 11 million. The present study highlights the use of restored teeth in a real exhumation case and the powder-free approach specifically designed for the extraction of DNA from teeth is discussed.