Teeth Hold Clues : Dentist Tracks Down Identities of the Dead

Most of the time, John Berk considers himself a regular family-style dentist.

But about once a month, his practice takes a sharp turn from the ordinary, and he becomes dentist to the unknown dead for the Alameda County coroner’s office.

In most cases, his job as forensic odontologist is to identify the dead by their teeth.

One case involved murder on a South Seas island. It involved a man convicted of grand theft in Hawaii after he sailed a yacht into port and tried to sell it. The owners of the ship could not be located.

Several years later, a yachtsman stopped at an uninhabited island to replenish his water supply and found a collection of human bones. The San Leandro dentist was called into the case and identified a skull found on the island as belonging to the wife of the Hawaiian yacht’s owner.

The yacht thief later was convicted of murdering the couple so that he could steal their boat.

At other times, Berk has been asked to identify individuals whose teeth may have been responsible for bite marks that were clues to murder cases.

“Bite-mark analysis is the leading edge of forensic dentistry,” he said. “It turns out there is a lot of biting going on in sex crimes, murders and rapes and the like.”

A bite mark was involved in a Vallejo-area murder. An apple with a bite taken out of it was found near a murder scene. Berk was able to testify that the suspect could have taken the bite from the apple. That, combined with other evidence, led to conviction.

A relatively recent case involved a long-dead body found under the home of a woman whose husband had not been seen for several years. Berk obtained dental charts and positively identified the body.

He makes about one identification a month for Alameda County. His most common task is identifying bodies burned beyond recognition.

“The coroner will not issue a death certificate without positive identification,” Berk said. “Personal effects found with a body are just not enough. They may have been stolen.”

The field is relatively unknown, and there are only about 100 dentists across the country certified to handle such chores, using dental charts and other methods.

The charts describe all 32 teeth, with notations on five surfaces of each tooth, Berk said.

“This business forcibly reminds one of how fragile is life,” Berk said.