Personal identification of living people and corpses: usefulness and reliability of intraoral scanners and 3D technologies in modern forensic dentistry

Teeth and oral structures are considered valuable alternatives to DNA analysis and fingerprints for personal identification. Even if their reliability has been recognized, they’ve not been widely or at all tested with new technologies. This project had the aim to study the superimposability of dental and oral structures in radiographic examinations and 3D scans and stability of some of them, like palatal rugae, in patients undergoing to dental procedures and cadavers. The survey has been performed on the virtual and plastic reconstruction of the oral cavities developed from data collected from an innovative intraoral scanner and from orthopantomographs (in all patients and cadavers- if available -) and from full-mouth periapical films (in periodontal patients and cadavers only). In all the patients oral cavity scans started at the beginning of the therapeutic procedures and after one year. In cadavers oral cavity scans have been recorded on the first and the seventh or tenth day from the time of death, allowing a complete survey on how long the palatal rugae features and other oral structures remain stable after corruption of the body sets in their intraoral scans have been then superimposed on radiographs. Morphometric data collected from all the virtual and plastic reconstructions and radiographs, have been listed in an electronic paper. The statistical analysis estimated the differences in shape and length of palatal rugae and dental and other intraoral features in the groups. The results confirm the reliability and the superimposability of 2D radiographs with the reconstructions derived from 3D scans as tools for personal identification, allowing to develop a new protocol for personal identification overcomes the so traditional and so invasive oral autopsy.