A CAD and AM process for maxillofacial prostheses bar-clip retention

Purpose-This paper aims to present novel techniques for designing maxillofacial prostheses using computer aided design (CAD) and additive manufacture (AM), focusing on the integration of osseointegrated retention components. A fully computer-aided approach is considered as a major step towards reducing patient consultation time and an efficient workflow. Design/methodology/approach-The workflow was illustrated through a phantom model. 3D laser scanning was used to capture the phantom anatomy and pre-fabricated geometric features, which enabled the implant positions to be precisely reverse engineered in the data. A novel CAD workflow was used to design the retention mechanisms and a mould. The individual components were fabricated using AM. A definitive silicone prosthesis that incorporated a bar/clip retention mechanism was then fabricated. Findings-The research demonstrated that retention components can be integrated into prostheses using appropriate CAD and AM technologies. Originality/value-This study demonstrates the feasibility of a computer-aided workflow for designing facial prostheses that incorporate osseointegrated retention mechanisms. Novel techniques were developed to: digitise abutment details using custom scanning locators; design retention components; manufacture retention components using AM; integrate retention components into a CAD and AM prosthesis mould. This overcomes limitations identified in previously published cases and demonstrated significant potential to reduce patient consultation time and create a clinically viable process.