The Application of 3D Image Acquisition Systems to Palatal Rugae: A Technical Improvement for Personal Identification? Daniele Maria GIBELLI 1,2 , Danilo DE ANGELIS 2 , Riccardo LUPI 3 , Paolo DANESINO 3 , Mike MARIC 3 , Valentina PUCCIARELLI 1 , Chiarella SFORZA 1* 1 Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Milano, Italy; 2 LABANOF, Laboratorio di Antropologia e Odontologia Forense, Dipartimento di Science Biomediche per la Salute, Università degli Studi di Milano, Milano, Italy; 3 Università degli Studi di Pavia, Pavia, Italy DOI: 10.15221/16.105 http://dx.doi.org/10.15221/16.105 Abstract 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. Keywords: Palatal rugae, laser scanner, 3D scan 1. Introduction Palatal rugae are irregular ridges made of connective tissue across the anterior portion of the palate and have long been considered a stable and unique marker on each individual [1]. The anatomical importance of such structures may provide relevant application to clinical and forensic fields of research: for example, they can be used in order to identify unknown decedents, i.e. cadavers without a specific identity which needs to be verified through biological means. The need for personal identification of unknown decedents is an urging need in forensic anthropology: for example, in Milan, one of the most populated cities in Italy, every year 32 new cases of unknown decedents occur (3% of all postmortem examinations) [2]. Personal identification can be obtained through the comparison of individualizing features from the body (postmortem data) and from the suspect of identity (antemortem data). The comparison of palatal rugae may provide a crucial help in order to reach a personal identification [3]. In addition, palatal rugae are analysed also from a clinical point of view, as they can be used as reference structures to measure teeth migration during orthodontic therapy; they are also useful markers to detect submucosal clefts in the palate [4]. Most of the above mentioned fields of applications rely on the supposed stability of palatal rugae with time: however, suprisingly there are conflicting opinions in literature, and several dark points still need to be enlightened. A relevant issue concerns the possible modifications suffered by palatal rugae with growth: common opinion is that palatal rugae are not affected by growth and remain unchanged until death with decomposition of soft tissues [5,6]. On the other hand, other authors suggest that palatal rugae may be modified in length because of the growth of the palatal plate [7], together with the movements of teeth [8]. * chiarella.sforza@unimi.it; +39 02 503 15387; www.scibis.unimi.it Proceedings of the 7th International Conference on 3D Body Scanning Technologies, Lugano, Switzerland, 30 Nov.-1 Dec. 2016 105