Dental ID, bite-marks and age assessment

Forensic odontology is useful in three important areas:

· Dental identification – This is conducted in situations where the identity of the dead is not known.

People’s dental structures do not change and this is a good tool, especially in a disaster, where the victims may be disfigured, burned, putrefied, badly skeletonized or traumatized, says Dr. Jayanie Weeratna, pointing out that under normal circumstances, identification is performed by looking at the face but in these cases it is very easy to make a mistake.

Even though personal belongings and clothes can also be used in identification, it is not a scientific method and thus not too reliable, as also jewellery which may not be unique to an individual.

· Bite-mark analysis – Bite-marks are usually from any animal which has teeth and include human or non-human, mainly dogs and monkeys.

Dr. Weeratna says that here a Forensic Odontologist looks at the injury, takes photographs and analyses them. In humans, there would be certain typical individualistic (peculiar) characteristics such as spaces between teeth etc., which would be taken into account. Then there would be reconstruction to determine whether the bite-mark is from the top or bottom jaws. Thereafter, a cast of the mouth of the suspect alleged to have made the bite would be taken and confirmation made by superimposition and tallying.

“As the skin is elastic and the area where the bite has occurred could get distorted if there is a struggle and also in the process of healing, the correct identification of a suspect/s who may have been responsible needs to be handled with caution,” she reiterates.

Bite-mark analysis is like a doubleedged knife. If you get it right, it is good but if you get it wrong there can be major repercussions on an innocent person. This is why there is a need to be very careful and skill, training and experience come strongly into play. In bite-mark injuries, teeth are the weapon, like a knife in a stab wound. It is a pattern injury. Sometimes even the perpetrator of a crime may suffer bitemarks from the victim, she says, adding that a person could also try to implicate another by making the bite-mark himself/herself.

· Age assessment – Forensic odontology is also used to determine the age of children if their births have not been registered or where there is fear of a birth- certificate forgery.

Pointing out that the teeth start developing from intra-uterine life (from the time the baby is four weeks in the womb) until he/she becomes 18 years, Dr. Weeratna says they include the first teeth (baby teeth which ex-foliate) and later adult teeth.

“We can determine the age of a child or young person up to 17 years within an age-range of six months. If the person is older, we can give the age within a larger time frame. Therefore, up to about 25 years, we can check out the dental development and wear and tear and do age assessments using other criteria as well, such as volume of a tooth,” she adds.