The diversity of adult dental patterns in the United States and the implications for personal identification.

Few would argue about the individuality of dental radiographs for forensic identification, but when an antemortem/postmortem comparison is based strictly on dental treatment notes and/or charts it becomes less certain. In the past, attempts to validate the high diversity of dental patterns created by combinations of missing, filled, and unrestored teeth have been based on unfounded statistical assumptions. The goal of this research is to present a statistically valid method of assessing dental pattern diversity for the identification of missing individuals. Empirical observation of large reference datasets was found to be the best technique for assessing dental diversity. This technique is nearly identical to the procedure used for mitochondrial DNA casework. For the research presented in this paper, two large datasets were used, one composed of U.S. military personnel and one composed of U.S. civilians. Dental patterns were found to be very diverse on a scale that is comparable to mtDNA. In addition, it was found that the diversity values remain very consistent regardless of the level of detail present in the treatment records. Overall, combinations of missing, filled, and unrestored teeth were found to be very individualistic and an excellent source for forensic identification.