September, 2002
Dear Dr. Mady: Why do police use dental records to put a name to an unidentified body? Isn't DNA matching much easier and more accurate?-Donald in Amherstburg
Dear Donald: Although DNA matching is a revolutionary and accurate method of connecting an identity to human remains, the configuration of an individual's teeth is still the most common and cost effective method of identification. Any forensic expert will first look at accessing dental records and matching them before exploring other avenues.One of the main reasons that teeth themselves provide excellent clues in identifying one's remains is because they are often all that is left intact after death. Basically, if a body is severely decomposed, the teeth may not even be affected at all.
The human dentition has a tremendous degree of permanence because it is so difficult to destroy. Fingerprints are an excellent way of identifying someone, but they often decompose rapidly along with the rest of the body, especially if exposed to the elements. Flesh breaks down very quickly as opposed to enamel, which does not decompose at all. Tooth structure is even much more resilient and durable than bone tissue itself. Even if a human is burned, their teeth are usually free from damage and identifiable, unless the remains were exposed to an extremely high temperature fire.
Each person's teeth, when viewed through dental x-rays, are so valuable because they can be compared with radiographs taken on a corpse and the exact size and contour of the teeth along with the type and shape of the fillings, can be analyzed for similarities. I have identified bodies on two occasions for investigators using my dental records and both times I obtained an exact match. It was not the most pleasurable experience of my career due to the fact that I knew these people on a personal level, but I realized that what I did was very helpful to the police and to the families. Forensic techniques such as this can assist disturbed loved ones in achieving some degree of closure and peace of mind, if that is at all possible and at times may even prompt payment of needed life insurance benefits.
Just like fingerprints or DNA, records of missing teeth and a verbal description alone can even be helpful in a determination. Dental records were most likely the primary source of identification after the 911 attacks in New York in 2001. If families had provided dental records and other personal information, it would have made it much simpler for investigators to narrow down whom they may belong to. For example, if they had found the remains of a woman in her thirties, they would have looked only at dental records of females in their thirties.
In addition, many don't know but the inside of each tooth contains a cavity known as the pulp chamber. It is inside of this and the roots of the teeth that nerve fibers and blood vessels exist. A biopsy of this tissue can also be very helpful for DNA matching and has proven so on many occasions especially when a further match was required. Even through many types of trauma, the tooth can protect it's pulp, thus preserving it to a certain degree for some time.
DNA matching can be very complicated and costly, but when dental records cannot be used, something else must be. It is a long and involved process and the backlog of criminal cases can make waiting time for a DNA match seem like forever.Digital dental radiography is becoming very popular and this permits images of x-rays to be stored in computers. This is allowing authorities to develop a database, similar to the type used for fingerprints that may be extremely valuable in the future. So teeth may be a lot more important than you thought!!
This column is reprinted with the permission of the author and The Windsor Star. "Ask the Dentist" is written by Windsor dentist (and ECDS member), Dr. David Mady Jr.. The column appears the first Thursday of each month in the Windsor Star. Readers with questions can write to "Ask The Dentist", c/o The Windsor Star, 167 Ferry St., Windsor Ontario, N9A 4M5
