Study of Root Transparency in Different Postmortem Intervals Using Scanning Electron Microscopy

Area of Science:

• Forensic Anthropology
• Dental Forensics
• Paleopathology

Background:

• Accurate age estimation is crucial for human remains identification in forensics.
• Root dentin transparency is a common method for age estimation in adult teeth.
• Dentin transparency's reliability is questioned in archaeological contexts due to inconsistency.

Purpose of the Study:

• To investigate structural modifications in sclerotic dentin across varying postmortem intervals (PMIs).
• To assess the utility of sclerotic dentin analysis for estimating time since death in forensic and archaeological samples.

Main Methods:

• Analysis of 21 human monoradicular teeth with PMIs of 0, 1, 2, and 5 years, plus archaeological samples.
• Sample preparation included resin inclusion, sectioning, and polishing.
• Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) microanalysis for structural and chemical assessment.

Main Results:

• SEM revealed distinct tubular modifications with increasing PMI, including loss of peritubular collars and lumen obstruction by hyperdense material.
• EDX microanalysis showed variations in phosphocalcic ratios across different PMIs, particularly in pulp and canine regions.
• Observed changes suggest postmortem alterations to the mineral phase of sclerotic dentin.

Conclusions:

• Sclerotic dentin exhibits structural and chemical changes correlated with postmortem interval.
• These modifications offer potential for improving age estimation in forensic and archaeological human remains.
• Chemical and/or bacterial actions are hypothesized to drive postmortem changes in sclerotic dentin.