You can’t go in the teeth of the evidence

A FORENSIC odontologist is a dentist who specialises in interpreting dental evidence for the courts. The British Association for Forensic Odontology is the professional association of these experts, and maintains a list of active odontologists.

Most of the work done by these experts involves the identification of human remains. In many cases the dental examination can give an indication of the age of the person at the time of death, which can help to reduce the number of missing persons being considered. Then dental records of the missing persons are compared with the dental condition of the body and an identification may be confirmed. The odontologist will prepare a written report for the Coroner, but is rarely called to support it in person.

If the investigation is one of homicide, the odontologist can give more information about injuries to the head, and also what injuries may have been made by the teeth of an assailant. That expertise can be extended to examination of the living: victims of assault. The odontologist has now migrated from examining teeth in the mortuary to examining marks on skin in police stations. This time the odontologist’s statement is for the court and they may well have to appear.

Some odontologists are involved in analysis of weapon marks, since the experience of analysing and interpreting the marks made by teeth is exactly applicable to marks made by other instruments. And the ability to estimate age from radiographs of the jaws is used more and more in cases of asylum seekers, whose entitlement to benefits decreases with age, and whose documentation may not be all one would wish.

There are problems at present with the prosecution of bite mark cases. The first is the relative rarity of forensic odontologists, so that it may not be possible to get an opinion about an injury very quickly. By the time good photographs are taken the mark may have faded considerably, and evidence has been lost.

The second is that, although it is sometimes possible to treat a bite mark like a fingerprint and get a positive identification, that is not always the case. It is not unknown for faked bite marks to reach court.

A fictional example in the recent Wallace and Gromit film A Matter of Loaf and Death occurs when the Bake O Lite girl bites herself on the forearm, and has Gromit imprisoned for it.

Gromit’s defence should have been able to show that the mark, although definitely caused by teeth, was not a dog bite and was in a position where it could have been self inflicted. Since Wallace was the only other person present, dental casts of his teeth should have been able to eliminate him.

Although the example is fiction, and comedy at that, such events certainly occur in real life.