3‑D Scanning Brings New Hope to Bite‑Mark Forensics

Bite marks can act like fingerprints, helping police link a suspect to a crime. Traditionally, experts look at photos and make measurements by eye—a process that can vary from one person to another. A new experiment tried a different route: using a 3‑D scanner and computer programs to compare bite marks on skin with models of teeth.

The Experiment

• Materials: Twelve full sets of dental molds (upper and lower jaws).
• Procedure:
  1. Created 24 bite marks on human skin in a lab setting.
  2. Scanned all molds and marks with an iTero 3‑D device.
  3. Edited scans in MeshMixer, then matched using CloudCompare.

Key Findings

• Matching Accuracy:
• Each bite mark matched closely only with its own set of teeth.
• Mismatched pairs showed clear differences.
• Jaw Comparison: No noticeable difference between upper and lower jaws in the matching process.

Implications

• Digital 3‑D comparison can distinguish matched from unmatched bite marks under controlled conditions.
• Data Sets are preserved for future review, enabling other experts to examine the results later.

Caveats

While encouraging, this technique still requires further testing before it can be reliably used in court cases.