Feasibility study of a methodology using additive manufacture to produce silicone ear prostheses

Abstract

In the current years, many kinds of prostheses have been developed to replace parts with deformity or absent from the human body. Facial prosthesis production methods have undergone little change in the last 40 years. Today, manual techniques are used to produce prostheses, which are usually cast in wax over a replica of the patient’s anatomy. Silicone is the most appropriate structural material used in the production of atrial prostheses due to its mechanical and chemical characteristics. Recently, new technologies, such as 3D scanning and additive manufacturing techniques are being applied in the production of auricular prostheses with better cost/quality relation when compared to the manual manufacturing process. In this research, four methods to acquire the structure of a human ear were investigated (photogrammetry, 3D scanning, 3D reconstruction of computed tomography images and parameterized 3D modeling) to produce auricular prosthesis molds by additive manufacture using the fused deposition modeling (FDM) technique. The best silicone ear prosthesis produced shows an excellent esthetic result with 0.1–3% of dimensional error. Mechanical analysis of the silicone (tensile strength and hardness tests) shows that the prostheses produced have excellent mechanical resistance that is not altered by the pigmentation process. The research demonstrates the feasibility of an accessible methodology to produce ear prostheses using free software, technologies and supplies available in the market.