Sex identification from exfoliated primary teeth--a PCR study

Area of Science:

• Forensic Odontology
• Molecular Biology
• Genetics

Background:

• Teeth offer superior postmortem DNA preservation compared to other tissues.
• Child abuse cases often rely on dental evidence when other remains are degraded.
• Exfoliated primary teeth can provide crucial DNA evidence in forensic investigations.

Purpose of the Study:

• To establish a Polymerase Chain Reaction (PCR) based method for sex determination in children using exfoliated deciduous teeth.
• To assess the efficacy of DNA analysis from teeth for forensic identification in child abuse cases.

Main Methods:

• DNA was isolated from dental pulp tissue of deciduous teeth using proteinase-K digestion and phenol-chloroform extraction.
• Polymerase Chain Reaction (PCR) amplification was performed using X and Y-specific oligonucleotide primers.
• Sex determination was confirmed by comparing amplified DNA sequences with male and female controls.

Main Results:

• The PCR-based method achieved 100% accuracy for sex determination in teeth collected within 24 hours and up to 1 month post-extraction.
• Successful DNA extraction and sex determination were possible even after significant postmortem degradation.
• The method proved ineffective for sex determination in teeth stored for over 6 months post-extraction.

Conclusions:

• Polymerase Chain Reaction (PCR) analysis of DNA from deciduous teeth is a reliable method for child sex determination in forensic contexts.
• This technique is valuable for identifying victims in cases of child abuse and neglect, especially when other evidence is compromised.
• The time sensitivity of DNA degradation necessitates prompt analysis of dental evidence, ideally within one month of extraction.