Orbital prosthesis wax pattern production using computer aided design and rapid prototyping techniques

Abstract

This research explored the application of advanced, digital methods of designing facial prosthesis patterns and evaluated them though a clinical case study. The work was undertaken by PDR Medical Applications groups in a long-term collaboration with Morriston Hospital.

Digital design techniques remain relatively underexploited in maxillofacial prosthetics due to technical and economic challenges faced by this small, specialist profession. Conventional methods rely upon laborious, handcrafting techniques and the need to embrace technological innovation is recognised within the profession. This research evaluates new technological methods that might provide clinically viable solutions.

A suitable orbital prosthesis patient case was selected by the maxillofacial unit at Morriston Hospital, Swansea. Medical CT scan data acquired for implant planning was used to obtain the soft tissue topography. A new 3D computer-aided design and sculpting package, FreeForm, was used to design an orbital prosthesis pattern based upon the mirroring and manipulation of the unaffected eye. Once judged clinically acceptable, ThermoJet wax printing was used to produce a physical pattern that could be incorporated into the conventional prosthesis manufacturing process. A clinically acceptable prosthesis was provided to the patient.

This research demonstrated how appropriate digital methods might be successfully incorporated into conventional prosthesis construction and that this can help reduce overall construction time. This was one of the World's first reported cases of a digitally designed and fabricated facial prosthesis. These research findings indicated advantages over traditional practice and provided a foundation that guided subsequent case studies as part of an overall aim to establish the current capabilities of digital technologies in facial prosthetics.