Method of designing and manufacturing craniofacial soft tissue prostheses using Additive Manufacturing: A case study

Abstract

Personalized prostheses, in addition to restoring and recreating normal body function and appearance, also fully achieve true reconstruction. However, traditional approaches to prosthesis manufacturing can incur significant resource costs. Challenges in the field of prosthetics include the development of improved, user-friendly manufacturing workflows. It is therefore necessary to improve the method, for example, by using digital technologies. A difficult assignment is also the selection of appropriate biocompatible materials. This case report detailed a method of producing patient-specific epithesis using photogrammetry, CAD based sculpting, additive manufacturing (AM), and mold casting. The workflow covered three main steps: data capture, prosthesis design, and prosthesis manufacturing. The patient’s face was digitized using a digital single-lens reflex (DSLR) camera, while the manufacturing included, i.e., stereolithography (SLA) and Vacuum Casting (VC). The work resulted in two prototypes of facial epithesis: one-part orbital prosthesis and two-part orbital prosthesis. Different materials were used to make the epitheses: for the one-part epitheses it was a two-part polyurethane (PU) resin, and for the two-part epitheses it was epoxy resin and medical-grade silicone. The outcomes were then evaluated based on questionnaires and prosthetic weight differences. Unfortunately, none of the produced prostheses fully resolved all the examined issues. It was concluded that further work is necessary to select a material that would ensure appropriate aesthetic effects and fitting the prosthesis to the defect. However, the use of new technologies to produce patient-specific prostheses can provide significant benefits, such as saving time, reducing the cost, and reducing the necessary number of outpatient visits.