Similarity and match rates of the human dentition in three dimensions: relevance to bitemark analysis

Abstract

Uniqueness of the human dentition is a fundamental premise in bitemark analysis. Despite the importance of this key aspect of bitemark methodology, systematic studies of large populations have been limited. Furthermore, there have been no investigations of the significance of the third dimension with regard to dental uniqueness. One hundred digitally scanned mandibular models were analyzed in both 2D and three dimension (3D) using Landmark software. Additionally, 500 3D maxillary and mandibular sets were investigated for determining dental match rate. Statistical analysis was performed with geometric morphometric methods. Results show that measurements in 3D preserve more information about the dentition, reducing but not eliminating random matches in a sample population of 100 mandibular dentitions. Examination of pairs of maxillary and mandibular dentitions showed a substantial number of random matches (197 maxillary, 51 mandibular, one of both maxillary and mandibular). Conclusions indicate that a zero match rate cannot be claimed for the population studied.

The examination and identification of bite marks in foods using 3D scanning and 3D comparison methods

“…The first assumption is that the dentitions of the individuals are unique with respect to the position, shape, size and pattern, and the second one is that the bite mark represents these characteristics with sufficient detail to enable a comparison [2][3][4][5][6].…”

A quantitative method for comparing human dentition with tooth marks using three-dimensional technology and geometric morphometric analysis

“…With respect to the ICDs, the difference between matching and nonmatching was 15-fold in the maxilla and 2-fold in the mandible. In contrast, other authors have noted a greater discrepancy in mandibular vs maxillary dentitions, which they attributed to a higher incidence of crowding in the lower arch [25], although their findings cannot be extrapolated to bite injuries.…”

Patterns of Variation and Match Rates of the Anterior Biting Dentition: Characteristics of a Database of 3D‐Scanned Dentitions

“…There was one remaining match in both maxilla and mandible of two different specimens under the Procrustes protocol. This was the same pair seen in an earlier study using the same data set . Under the Procrustes‐SP procedure, there were two matched pairs of different specimens, for a total of four individuals with a match.…”

“…However, the number of matches in the combined data set did not increase when considering Procrustes superposition. There was only one matching pair, which had already been seen in an earlier study . The use of Procrustes‐SP methods , which had not been available in the earlier study, produced two matching pairs, of four individuals total, which did not include the individuals matching under the Procrustes criterion.…”

“…Procrustes methods and Procrustes-SP (also called "size and shape analysis") have been discussed extensively in numerous other publications (11,(13)(14)(15)(16)18,19,(21)(22)(23). Both methods simply minimize the summed squared distances between corresponding landmarks on two or more specimens by translating and rotating the specimens to match one another as well as possible.…”