A 3D printing system (including a mixing print head, silicone “ink” formulations and associated control software) is being developed that will directly print patient specific body/facial prostheses using digital images of the defect. The innovation is expected to significantly reduce the time taken to make prostheses and also reduce the number of clinical appointments and provide a more reliable result. It is also expected to achieve a better match to the patient’s skin colour and texture than is presently achievable making the prosthesis less noticeable.
Facial/body prostheses are often required for patients who have lost facial/body parts, such as an ear, nose, eye, finger, hand or breast or combinations of these. These defects can result from trauma, congenital malformations or diseases such as cancer. Improvements in medicine, surgical techniques and in particular cancer survival rates are resulting in increasing numbers of patients who require prostheses.
Typically, facial/body prostheses are manufactured by a lengthy multi-step process that involves taking an impression from the patient, hand carving the missing defect, creating a two or three part stone mould into which pigmented silicone is placed, colour matched to the surrounding tissue. These methods of prosthesis construction are time-consuming, involving five to six patient visits and results are dependent on the skills of the prosthetist.
The ability to 3D print biocompatible silicone presents a number of potentially significant product opportunities. These include:
- Body surface prostheses to replace missing non-articulated body parts (nose, ear, cheek, breast etc.)
- Patient specific coverings for prosthetic limbs.
- Patient specific anatomical models to enable surgeons to improve pre-operative planning of complex surgical procedures (e.g. to correct congenital abnormalities or to reconstruct following trauma).
- Patient specific biocompatible in-vivo medical devices or medical device components, where advanced silicones would be appropriate.
Dr Coward of King’s College London is a Reader in Maxillofacial and Craniofacial Rehabilitation at the university. The direct printing of silicones for prosthetic and medical device purposes was his motivation for the invention. Funding has been provided by the Defence Science & Technology Laboratory of the Ministry of Defence to improve treatment options for trauma victims; collaborators in this project are Dr Jim Smay of Oklahoma State University (responsible for the design of the mixing print head for silicone printing and its control software) and Prof Mark Waters of Technovent Ltd (developing compositions for biocompatible room-temperature curing silicones with suitable properties).
An International application (Application Number PCT/GB2015/050056; Publication Number WO2015/107333) was filed 13 Jan 2015, with a priority date of 14 Jan 2014.
KCL Principle Investigator: Dr Trevor Coward, Tissue Engineering & Biophotonics Department, Dental Institute
Dr Ceri J. Mathews
IP & Licensing Manager
King’s College London