Bite Mark Evidence: Evaluating Styrofoam and Wax Sheet as an Alternative Registration Media

Forensic odontology is a branch of forensic sciences that deals with personal identification during mass disasters, sexual violence, child abuse, etc., using the knowledge and skills of the dentist. Bitemarks are observed at the crime scene such as in cases of sexual assault and can be used for identification purposes and play a very useful role in providing dental evidence against convicts.

Maxillary and mandibular impressions of 50 males and female subjects were taken along with cast preparation. Furthermore, two sets of test bites were recorded with test materials, i.e., wax sheet and Styrofoam. First set was kept at room temperature, and second was kept at 4°C. The reference overlays were generated from dental cast and test materials on the first day and the fourth day. They were evaluated by both metric and nonmetric methods.

When the reference overlay was compared with test overlay, wax sheet showed a higher correlation coefficient at room temperature, whereas Styrofoam showed a higher correlation at 4°C. Based on time lapse, test overlays of Styrofoam showed a high correlation coefficient on fourth day as compared with overlays from wax sheet.

The wax and Styrofoam can be used as bite registration media on special conditions such as trismus, bed ridden individual, and mentally retarded subjects.