Identificação humana através da análise de marcas de mordidas por diferentes técnicas de rastreamento e substâncias alimentares.

Abstract

The Legal Dentistry acts in the identification of living persons and cadavers through the dental arch and is based on the individual characteristics of the dental elements and on the resistance of these elements the extreme environmental conditions. Bite marks are described in the literature as important expert elements for identifying victims and criminals, are very common in crime scenes and are often the only criminal traces the forensic odontologist can count on during the investigation. Faced with this, the study of dental impressions has been increasingly relevant and necessary. This work aims to analyze the accuracy of the screening techniques commonly used in the analysis of bite marks and the possibility of identification of the author of the bite in food substances. The sample was selected after approval by the Ethics Committee and had 30 students from the dentistry course of the Federal University of Campina Grande - Patos campus, which had all the anterior upper and lower natural teeth. The work consists of two phases. In the first phase, the 30 selected students were cast with alginate and cast in stone gypsum. The upper and lower anterior teeth of the gypsum models were drawn in a transparent acetate sheet with a 0,5 mm felt tip. Three tracing techniques were simulated: manual, wax and radiographic printing from the wax impression by confronting the acetate sheet previously delineated to determine the match. In the second phase, seven of the 30 students belonging to the sample bitten two food substances: cheese and guava. The molding of these foods was carried out and, later, the models in plaster were obtained. These templates were confronted with acetate sheets to determine matching. The evaluation was performed by two examiners, and for the calibration, 20 models of gypsum were used that were not part of the sample, using exactly the same methodology described above, which lasted 2 (two) weeks. the analysis of intra and inter-examiner agreement was done by means of the kappa test (0.89 and 0.81, respectively). Blinding was done by removing all posterior teeth and palatal wrinkles to eliminate bias. All of the screening methods presented good results, with manual tracking showing the best results with excellent correspondence in 90% of cases, followed by wax printing with 76.7% and finally the radiographic method with only 26.7%. In the two food substances it was possible to correctly identify all the authors of the bite, and the guava presented better results with 87.5% of the cases with excellent correspondence, and the cheese with 57.1%. It is concluded that the tracing techniques analyzed presented good results and can be used in practice as long as they are executed correctly. Foods also presented excellent results, where guava presented as a better substrate for bite analysis than cheese, showing that they can serve as reliable and accurate evidence for the identification or exclusion of suspects.