Reconstrução facial forense: Desenvolvimento de marcadores de espessura de tecidos moles por CAD/CAM

Abstract

Forensic facial reconstruction (RFF) is the method of approximating an individual's appearance over a replica of a skull, guided by facial soft tissue thickness (METMF) markers of varied material. Each METMF has the thickness of the tissues at a certain point and must be cut, making it a time-consuming process. The objective of this work was to develop a three-dimensional model of METMF through the process known as computer aided design and computer aided manufacturing (CAD/CAM) to make a set of printable markers for use in manual RFFs, which can be distributed to Forensic Medical Institutes. With measurements of fabric thickness tables for Brazilians, 3D models of METMF of square, triangular, and semicircular sections were designed in CAD software, with shape and characteristics favoring printing. The prototypes were checked in the print preparation program and in CAM software, compared in terms of material consumption, time, need for supports, presence of alerts for errors, thickness, strength, slicing, dimensional stability, and applicability in simulated forensic practice. The three METMF formats printed for both sexes were viable, did not present errors during the technical design and printing process, did not require printing media and met the thickness and resistance specifications necessary for their practical application. In addition, the dimensional stability of the markers was adequate. The prototyping of METMFs for use in RFFs is an innovation and has considerable social relevance by contributing to the optimization of the work of RFF experts and assisting in the search for unrecognized missing persons. The work has successfully developed printable METMF prototypes, highlighting the triangular section model as the most efficient in terms of material consumption and potential print time for scale production.