Assessing the Micro- and Macroscopic Changes of Chemically Altered Human Bone and Teeth

Area of Science:

• Forensic Anthropology
• Forensic Chemistry
• Biomolecular Analysis

Background:

• Household chemicals like sodium hydroxide (NaOH) and hydrochloric acid (HCl) are used in forensic contexts to disfigure remains.
• While NaOH dissolves soft tissue, its effect on bone and teeth structure is less understood.
• HCl rapidly demineralizes hard tissues, posing challenges for identification.

Purpose of the Study:

• To comprehensively assess micro- and macroscopic changes in bone and teeth after chemical exposure.
• To investigate how factors like shape and surface area-to-volume ratio influence chemical alteration.
• To evaluate DNA isolation feasibility and profiling from chemically altered remains.

Main Methods:

• Chemical treatment of bone and teeth samples with NaOH and HCl.
• Microscopic and macroscopic analysis of structural and compositional changes.
• DNA extraction, quantification, and Short Tandem Repeat (STR) profiling.

Main Results:

• Alteration patterns and DNA yields varied non-linearly with chemical treatment and exposure duration.
• Teeth yielded higher quality and quantity of DNA compared to bones.
• Complete STR profiles were successfully obtained from all tooth samples.

Conclusions:

• Chemical alterations to skeletal remains present challenges for identification.
• Teeth are superior to bones for DNA recovery and profiling after chemical exposure.
• Further research is needed for effective identification methods for taphonomically altered remains.