The application of 3D image acquisition systems to Palatal rugae : a technical improvement for personal identification?

The modern 3D image acquisition systems have acquired in the last decades a growing importance in clinical anatomy and in different fields of application of physical anthropology, including also forensic issues. An example can be found in the development of novel procedures concerning the comparison of palatal anatomical structures, such as palatal rugae. This study aims at exposing possible protocols of superimposition for the comparison of palatal rugae, useful for clinical and forensic purposes: the palate is acquired by a laser scanner (Dental Wing). Superimposition is then performed according to the surface of the three main palatal rugae through VAM software which is able to give back an estimation of RMS (root mean square) point-to-point distance between the two models. Models can be also assessed separating the right and the left side in order to test possible modifications of palatal structures in cases of maxillary expansion. The 3D superimposition provides a chromatic visualization of corresponding areas (areas with full superimposition are represented in green, whereas possible discordances are in blue or red) that offer a visual depiction of the quantified differences, useful in clinical contexts. The proposed protocol may therefore provide a relevant help in the assessment of palatal modifications in clinical anatomy and forensic anthropology.