Our title might be slightly deceiving since our teeth aren’t like a fingerprint, inherently unique from inside our mother’s womb. But dentition does often outlive the rest of our bodies in extraneous circumstances, leaving behind clue that have helped in many crime and scientific discoveries. Forensic dentistry, also called forensic odontology, is the appropriate handling of and examination of dental evidence for the issuance of justice. This can be in such cases as natural catastrophe victims’ identification to bite marks in heinous crimes such as homicide or rape.
What a Forensic Dentist Can Tell From Teeth
Though a tooth isn’t as distinct as a fingerprint, a system has been put into practice to help dentists distinguish certain traits that can help them identify the owner. Age can be determined by the eruption of the teeth, which averages 4 micrometers per day. Ethnicity can sometimes be identified because certain peoples have unique features on certain types of teeth (i.e. Asians or Native Americans can have a scooped-out shape to the back of their incisors.)
Enamel protects our inner teeth layers from cavities and food particles, but most people don’t know that the hard substance also can withstand high temperatures, up to two thousand degrees Fahrenheit. Granted, the tooth will be fragile, but with careful handling and preservation, a burnt body can be identified. The pulp of a tooth can also be extracted and DNA found within it. (Bet you were wondering where the genes come in.) Likewise, dental work such as dentures, crowns, or partial bridges can also offer clues despite their warped or destroyed condition. Lastly, jaw surgery in a morgue may be necessary to uncover the full mouth and compare it to dental records, x-rays, or tooth charts of the dead.
The way people lived and their routine habits can also be determined by certain elements the forensic dentist discovers in the mouth of the deceased. Smoking or tobacco use, as well as certain profession duties may impact wear patterns or tooth fractures that a forensic dentist is trained to look for. (Source: science.howstuffworks.com)
What a Forensic Dentist Can Tell From Bite Marks
Perhaps the most notorious trial that utilized bite marks to convict a criminal was that of Ted Bundy and his killing spree in a fraternity house. Forensic dentists found a bite mark on one of the victims. With careful observation of the marks and getting a court order for Bundy to give a dental mold to compare to it, Bundy was locked up for life. This is just one example and may seem simplistic, but bite-mark analysis is a complex science. Many factors play into this branch of forensics, including:
• Immediate evaluation on scene is needed due to the fact that as the body is decaying and this change can make the muscles and skin slide, moving the marks. Swabbing for DNA is also important as instantaneously as possible for the best collection quality.
• Shape and type of marks differ between human and animal due to length and cleanliness of the biters mouths.
• Often, only the top or bottom teeth leave a clear impression, especially if the victim was moving at the time of the bite.
• Tongue and jaw movement during the attack can also influence the visibility and depth of the bite.
• Bite marks are categorized depending on various factors of the bite site. For example, an abrasion is a bite that scrapes the skin, and a hemorrhage is a bite that was bleeding excessively at the wound site. Other categories include artifact (piece of body removed), avulsion (skin removed), and laceration (a puncture).
• Photographs of bite marks are very important to preserve true measurements and bruising, as both of these can fade or change as the body decays. Rulers or other scale items must be used in photographs to accurately depict the size, positioning, and penetration of the bite.
Eventually, bite marks are cut off the skin of deceased victims and preserved in a formaldehyde mixture until a silicone cast of the bite mark can be made.
Just as your dentist makes an impression for complicated dental procedures, forensic scientists take note of impressions in bite marks to help them link evidence. For example, chipped teeth might leave a serrated impression with various depths into the victim’s skin. All of the information a forensic dentist finds and theorizes is written into reports that are kept as evidence to the corresponding case.
Want to become a Forensic Dentist?
Forensic dentists are often employed by a state or local agency, usually in cahoots with a coroner or medical examiner. They must have proof of a Doctor of Dental Science degree, as well as specific training in forensics. The American Academy of Forensic Science (AAFS) offers the most well respected program, but the Armed Forces Institute of Pathology, the University of Texas, San Antonio, the New York Society of Forensic Dentistry, and the New York County Dental Society also offer wonderful training in the field.
While some might find the information above as disturbing, others might find it fascinating. If you’d like to know more about the career option, check out www.crimesceneinvestigatoredu.org/forensic-dentist.