Forensic Odontology: A Case Study

Identification of a Murder Victim

The following case provided by Dr Claudia Garrido-Varas (pictured above) will illustrate some of the benefits of dental forensic examination for human identification, using both a traditional autopsy and anthropological means.

Teeth have been studied intensively by clinicians and anthropologists in terms of anatomy, physiology, pathology and development. We discussed last week their use in estimating the age of a person at death.

We know that we need to look after our teeth, otherwise factors such as dental decay can progress and cause us a lot of pain, as well as lead to the loss of teeth.

At the dentist, teeth undergo a variety of treatments (amalgams, teeth colour restorations, ceramic crowns, gold crowns, etc.), they can also be extracted, implanted, moved with braces, etc. During these procedures, they are often radiographed, photographed, or moulded and records of such treatment are kept.

Dental identification relies upon an ante-mortem/post-mortem comparison. The key to a successful identification relies on adequate ante-mortem information (when the person was alive). Dental records can establish identity reliably, cheaply and quickly when compared to DNA analysis. The speed of identification is particularly crucial for family members who need to know the fate of their relative(s) as soon as possible.

Analysis of the Victim: Case Study

A female victim was found in an advanced state of decomposition, with total absence of facial features. She presented a peri-mortem fracture on the body of her mandible. The post mortem dental examination of her body revealed that she had numerous dental treatments. The information recorded from the unidentified body was compared to the chart of a female who had been missing for one week and who was the suspected victim. Radiographs of the dentition were also taken post-mortem to compare with ante-mortem dental records available for the suspected victim.

Ante-mortem and post-mortem radiographs from the female victim showing dental fillings

Ante-mortem and post-mortem radiographs from the female victim showing dental fillings

A table comparing the post-mortem records of the victim to the ante-mortem records of the person it is suspected to be

The table contains information about the 32 teeth in an adult dentition and a comparison between the ante-mortem and post-mortem findings. The nomenclature and description of the findings have been simplified for teaching purposes. In the post-mortem column, the information from the forensic dental examination is recorded. The teeth highlighted in red contain very important information that can be used for identification purposes, such as fillings, root channel treatments, tooth loss, etc. When ‘sound’ is recorded it means that the tooth is healthy and ‘absent’ means that the tooth was lost during life, most likely due to an extraction.

‘Empty socket’ means that the tooth fell from the socket and was not recovered (this can happen due to the decomposition process). Unrecovered teeth present a problem in the sense that there is information missing. The missing teeth could have had fillings or other characteristics that could have been useful for identification. It is fairly common for teeth to fall from their sockets naturally during the decomposition process, so it is crucial that the person recovering/exhuming the dead body is aware of this possibility.

The column of the ante-mortem information has very specific information regarding some teeth (highlighted in red), but very poor information about the rest of the teeth. Although dentists are encouraged to keep complete dental records of their patients, some only keep information regarding the treatment they provide to the patient.

The case presented is a simplified example, that illustrates the principles of dental identification as well as the challenges, e.g. incomplete ante-mortem records. Although there were some teeth missing, and the dental records were incomplete, the specificity of the information, including the presence of ante-mortem radiographs, permitted the identification of the deceased.

In this case, the forensic dental examination, and subsequent identification allowed for a fast release (repatriation) of the remains and allowed the police to continue their murder investigation with confirmed facts, such as identity and peri-mortem trauma.