Question 1 (Part 1): Identification of Victims with Bite Marks

Picture adapted from www.uthealthleader.org

Forensic odontologists play a vital role in identification of victims with bite marks. As we all know, tooth is the hardest structure found in human beings. During violent assaults such as sexual assault, rape, physical abuse, and murder, teeth can be used as an effective weapon. Victims often use their teeth as a self-defensive weapon to inflict injury on assailants. On the other hand, assailants are commonly known to attack the victims by biting them intentionally due to their enraged manner, especially in the case of child abuse. Distinct bite marks has the potential to link the assailant and the victim.  

Analysis, Comparison & Identification

Picture adapted from www.nlm.nih.gov

In bite mark analysis, bite marks with unique traits are used to compare with the suspect’s teeth imprint pattern tracings. Note that the bite marks must first be established as a human bite mark by identifying specific types of teeth via their class characteristics. 

Presence of some characteristics in the injury such as rotations, malocclusions, fractures, restorations, congenital malformations and etc could facilitate the forensic dentist to analyse the bite marks. However, the overall significance of bite marks can be decreased when these features are absent in the injury. 

Forensic dentist must understand tooth morphology, dental arch characteristics, occlusions and etc thoroughly in order to carry out bite mark analysis accurately.

How are evidences collected from bite victim?

Picture adapted from www.utforensic.org

Dental forensic examiner, despite recording the documentation of physical appearance, size, orientation and location of bite marks, must take close-up photographs using intra-oral camera with a reference scale to allow following measurements. Albeit both colour and black-and-white film photography remain as the standard, digital photography are well-accepted. Subcutaneous evidence of bite mark damage can be identified by using infrared photography.

Saliva swabs (if applicable) should be collected from the bitten surface on the victim along with a DNA sample. These will later be analysed and amplified (eg: Polymerase Chain Reaction (PCR) analysis) to make comparison between the samples and bite marks, resulting in identifying association between the biter and the injury.

A precise impression of the bitten surface should be taken in order to inspect the presence of any irregularities caused by the teeth.

How are evidences collected from bite suspect?

It is necessary to perform a clinical examination on the suspect, including extra-oral and intra-oral examinations. Extensive photographs, impressions as well as bite sample should be collected for subsequent analysis. These procedures could only be done after obtaining a court-ordered search warrant.

Summary

Forensic dentistry field is still working until today to increase the scientific validity for human bite marks to provide adequate evidence for jurisprudence purpose.

Reference: http://www.forensic-dentistry.info/wp/?page_id=9