Dental Biometrics for Human Identification

In the history of civilization, the human identification based on dental information was first reported in the Roman Empire, when Nero’s mother, Agripina, ordered the killing of Loilla Paulina, who was later identified by her dental caries and bad dental occlusion (Couto, 2009). The first treatise on human identification using dental records was conducted, in 1897, by Dr. Oscar Amoedo Valdés (1863-1945), a Cuban doctor, president of the French Dental Society and professor of the Paris Dental School, who applied a dental-based identification technique in order to reveal the identity of victims of a disaster which occurred in Paris (Amoedo, 1897). Since Dr. Amoedo’s work, the Forensic Dentistry has attracted much attention, and the importance of using dental records for human identification is nowadays accepted worldwide (Chen & Jain, 2005). During the last decade, dental records have been extensively used in order to identify the victims of massive disasters, such as the 9/11 terrorist attack in New York (O’Shaughnessy, 2002) and the tsunami in Asia (Thepgumpanat, 2005). In Forensic Dentistry, the human experts perform manual comparisons of ante-mortem (AM) and post-mortem (PM) dental records, looking for similarities (Jain & Chen, 2004). During this manual approach, the main characteristics used to compare dental records are: the presence or absence of a specific tooth, the morphology and dental restoration of the teeth, periodontal tissue characteristics, pathologies and other anatomical features. Figure 1 shows panoramic radiographs of two distinct individuals. One can easily observe several differences between these radiographs. In contrast to other popular biometric characteristics, dental features do change over time, causing great difficulties during the identification task. The teeth can change in appearance as a result of dental restorations, or can be missing altogether due to an accident which occurred after the AM records were taken. For this reason, although accepted in courts of law, dental based identification is considered less reliable than other biometric methods (Jain et al., 2003). Figure 2 shows panoramic radiographs of the same individual taken at two separate occasions during a period of three years. The dental patterns are almost the same, but changes due to dental restorations can be observed. Despite known drawbacks of these identification methods, dental information may be the only available mean for identification in many disaster scenarios and mass accidents like fire and plane crashes. The other popular methods of identification are impossible since physical traits like faces and fingerprints are, in general, completely destroyed in such events 3