Bitemark analysis is often used in criminal cases in the United States. Bitemarks can occur during assaults, homicides and domestic abuse cases. The perpetrator’s bite leaves a pattern of his/her teeth in the skin of the victim. Authorities then attempt to match the suspect’s tooth pattern with the pattern on the victim’s skin.
But a recent report by the National Academy of Sciences (NAS) raised questions about the reliability and validity of bitemark analysis. Bitemark technique assumes that the arrangement of an individual’s teeth is unique to that person. It also assumes that these dental features reliably transfer to and are recorded in the skin. But there is little scientific backing for either assumption. Nevertheless, bitemark analysis is accepted in all of the states and its admissibility is rarely challenged. Its admissibility was established in the 1970’s but a number of recent cases have highlighted its unreliability. For example, Robert Lee Stinson was convicted on the basis of bitemark evidence and served 23 years in prison before he was set free due to testing of DNA evidence.
Bitemark analysis might have some use in the courtroom but it needs to be further studied so there is some scientific basis for the approach. (Ref: JADA, Guest Editorial, Sept, 2011 (http://jada.ada.org/content/142/9/997.full).