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Strive-the Student View Forensic Dentistry: The Stories a Tooth Can Tell By Laura Garibay, RDH, BS, and Crystal Talbert, RDH, BS For centuries, forensic dentistry has been used as a crucial scientific means of identifying both the living and the dead. It is based on the theory that all persons are unique because they are either born with anomalies (e.g., mesiodens) or they acquire artifacts in the course of their lifetime (e.g., restorations).
Microscopic features known as Barr bodies are found only in females and are used along with DNA and skull shape in sex differentiation. To determine race and national origin, the forensic team examines mid-facial skeletal structures as well as the maxillary dental arcades. Some ethnic groups have very unique dental morphologies such as distinctly larger cusps of Carabelli and shovel-shaped incisors.[1] Socioeconomic status can be yet another important factor in establishing a person's identity, and it can be determined through analyzing the presence or absence of restorative work versus extractions, or looking at different types of restorative materials used. Because of its resistant nature, enamel houses and protects the valuable pulpal DNA from environmental attacks such as fire, emersion and decomposition, and it can survive most impact trauma. At times, DNA within the pulp may be the only DNA available for the legal team to work with.[2] Methods, Processes and Tools Forensic dentistry is one of the best approaches to identifying burned and decomposed victims and has been proven superior to other methods when called upon for use in mass disasters. In fact, almost all aviation crash victims are identified via forensic dentistry. This is due to the strength and durability of enamel, which can withstand trauma that other tissues in the body cannot. Dental hygienists familiar with identifying dental anomalies and their etiologies can assist the forensic team in the identification process. Long-term oral habits (e.g., pipe smoking, use of toothpicks) cause predictable changes in the dentition. In addition, findings such as tooth staining associated with tetracycline medication or tobacco, as well as the erosion seen with GERD or bulimia, can be of assistance in the identification process. Furthermore, some occupations can present with characteristic wear facets. For example, carpenters and seamstresses are known to hold nails and pins in their teeth while working and can, over a prolonged period of time, develop noticeable patterns of wear.[1] More often, family members help to confirm individuals' identities, since they are familiar with the persons' oral habits and conditions. Other important tools used in identification may be antemortem and postmortem radiographs, clinical and personal photographs, study casts, appliances such as retainers and prostheses such as partials and dentures. A conclusion can be made after deciphering all available data. There are four classifications of conclusions ranging from positive to exclusive. A "positive" conclusion can be made only when all antemortem and postmortem data clearly substantiate the identity and there are no discrepancies. A "possible" identification can be made when data has consistencies, but its quality hinders positive identification. The third classification of conclusions is "insufficient evidence," in which there is not enough data to form a definite solution. In "exclusion," evidence is inconsistent with the suspected identity and clearly rules out the person under investigation.[1,3] A Historical Overview Many readers may be familiar with some of the following historical cases resolved by means of forensic dentistry. One of the first documented cases in U.S. history involves a set of dentures made by Paul Revere for a general named Joseph Warren during the Revolutionary War. Upon this general's death, these dentures became the primary evidence in identifying him.[4] In other historical cases, forensic science has answered questions dating as far back as the 14th century. Scientists have excavated gravesites seeking specific causes of death for those thought to have died of the plague. The bacterium Yersenia pestis found within dental pulp gave a positive conclusion of death by the Black Plague. Since the pulp remains sterile from outside contaminants, bacteria found within it is guaranteed to have been present in the bloodstream prior to death.[5] In more recent history, the possible identification of Adolf Hitler's remains was attributed to forensic dentistry when antemortem radiographs were compared with photographs taken during a speech and with dental remains.[6] Bite marks are consistently associated with forensic dentistry. One of the best-known cases involving bite marks as evidence used to make a murder conviction was in the case of Florida vs. Theodore "Ted" Bundy, where the only concrete evidence that could be used was bite marks on the body of the victim. Bundy was found guilty beyond a reasonable doubt after the jury had seen photographs of indentations on the body alongside full-scale photographs of Bundy's teeth.[7] The Dental Hygienist's Role in Forensic Dentistry In the three most recent mass disasters alone, specifically 9/11, Hurricane Katrina, and the 2004 South Asian tsunami, over 5,000 persons have been identified mainly by comparison of dental records. With extensive dental knowledge in the areas of morphology, dental anomalies, taking and interpreting radiographs, and dental charting, dental hygienists can be highly qualified assets on the forensic odontology team. An excellent first step in getting involved and discovering more information regarding the area of forensic dentistry is through continuing education training courses sponsored by the American Society of Forensic Odontology. Other quick-study courses are offered by dental schools and medical examiners' offices throughout the country. A dental hygienist interested in forensics can become affiliated with a local forensic dental team through the medical examiner's office, a state dental identification team, or the Disaster Mortuary Operational Response Team (DMORT). Volunteering on one's own may be rather difficult, so participation with established organizations may be an easier avenue.[4] Some well-recognized organizations are listed under Forensic Web sites at the end of this column. It is easy to appreciate the significant contributions that forensic dentistry has achieved when considering the thousands of people it has allowed to be properly laid to rest. Due to the vast knowledge and skills that dental hygienists acquire through education and work experience, they are undoubtedly a critical component of the identification team. Numerous cases arise daily where we can be great contributors in finding resolutions.
Laura Garibay, RDH, BS, is a 2007 graduate of the University of Missouri-Kansas City, where she was a member of the forensic interdisciplinary practicum. She attended the state meeting, Missouri Emergency Response Identification Team (MERIT), a branch of DMORT. She intends to volunteer in the forensic field throughout her career. She has taken a position in a public health clinic in southwest Missouri. Crystal Talbert, RDH, BS, is a recent graduate of University of Missouri-Kansas City School of Dentistry. During her academic career she was one of the two elected Student American Dental Hygienists' Association representatives. She is currently employed in rural Neosho, Missouri. Forensic Web Sites American Academy of Forensic Sciences American Board of Forensic Odontology American Society of Forensic Odontology Armed Forces Institute of Pathology
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The
first step in identifying a person that cannot be visually or otherwise
recognized is to establish their age, gender, and race.[
