Teeth as forensic evidence for SRY gene-based gender determination: a scoping review.

BACKGROUND

Establishing biological gender is essential for human identification. In disaster and medico-legal cases with mutilated, burnt, or decomposed remains, routine skeletal or soft-tissue markers may be unreliable. Teeth are highly resilient and can preserve nuclear DNA. This scoping review maps evidence on PCR-based SRY detection from teeth and oral exfoliated cells, summarizes diagnostic performance across sample types and environmental conditions, and highlights key methodological gaps for future research. MATERIALS AND

METHODS

This scoping review followed Joanna Briggs Institute guidance and was reported using the PRISMA-ScR framework. A structured search with MeSH and free-text terms was conducted, and the research question was framed using PIRT. Two reviewers independently screened studies and charted key data on design, sample type, DNA methods, PCR approach, exposure conditions, and outcomes. Methodological quality was also summarized using relevant JBI tools for contextual interpretation.

RESULTS

Four studies were included. Dental pulp was the most reliable substrate for SRY-based gender determination, achieving 100% sensitivity and specificity even after 60-day exposure to seawater, soil, and dry air, while dentin performed poorly. Extreme temperatures reduced sensitivity to ~ 46.7% despite high specificity (~ 93.3%). Among oral trace items, toothbrush samples showed lower specificity due to false positives in females, whereas miswak retained better accuracy over six months. Overall, findings suggest a clear substrate hierarchy favouring pulp over dentin and highlight the influence of environmental stress on test performance. These results also emphasize the need for strict contamination control in trace-item analysis. Standardized protocols and larger studies are required to strengthen real-world forensic applicability.

CONCLUSIONS

The mapped evidence supports dental pulp as the most reliable source for SRY-based gender determination in forensic scenarios. Oral trace items may offer practical value in specific contexts, but diagnostic performance varies with storage duration, contamination risk, and methodological heterogeneity.