Exploring the degrees of distortion in simulated human bite marks

Area of Science:

• Forensic Odontology
• Biomechanical Analysis

Background:

• Bite mark analysis is crucial in forensic investigations.
• Skin properties and body posture can influence the accuracy of bite mark interpretation.
• Previous studies have not fully quantified distortion under varying conditions.

Purpose of the Study:

• To quantify the degree of distortion in bite marks compared to touch marks.
• To assess how different arm positions affect bite mark distortion.
• To evaluate the impact of skin properties and posture on bite mark accuracy.

Main Methods:

• Created 'touch marks' and 'bite marks' on the upper arm of 30 subjects using inked dental casts.
• Photographed marks at three arm positions (relaxed, two flexed).
• Analyzed mesiodistal widths, incisor rotation angles, and inter-canine distances using digital imaging software and statistical analysis (ANOVA).

Main Results:

• Statistically significant differences in distortion were found between mark types and arm positions.
• Bite marks exhibited greater distortion than touch marks.
• Distortion in bite marks increased with changes in arm position.

Conclusions:

• Skin properties and body posture are significant factors causing distortion in bite mark injuries.
• The degree of distortion can lead to inaccurate measurements and potentially mislead pattern interpretation in forensic casework.
• Forensic practitioners must consider these variables during bite mark analysis.