Materials for facial prostheses in resource-limited countries

Facial prostheses are artificial devices that replace a missing body part in the facial and neck regions of the body. Defects or deformities in these regions can lead to functional deficiencies; social and psychological effects in addition to cosmetic defects. Restoration or rehabilitation in resource limited countries is usually provided by charities and organisations volunteering assistance overseas, with some training of local staff in the fabrication of these prostheses. Furthermore, these countries typically lack technical knowhow and trained personnel. In industrialised nations maxillofacial prosthetics has developed into a sophisticated medical speciality requiring highly skilled staff and expensive facilities. In resource limited countries surgical procedures may be an option for rehabilitation of these deformities/defects however, they tend to be unavailable or unaffordable and donated prostheses are not suitable. Hence, this research explores, from first principles, the appropriate and affordable local provision of maxillofacial prostheses in resource constrained regions. The investigation provides knowledge on identifying requirements for resource limited areas, resulting in the creation of a guideline constituting priorities, requirements and specifications. It further explores the viability of potentially cheaper, locally available candidate materials via weathering and antimicrobial methods in ascertaining material longevity.

Methods used in this study are computational materials search, qualitative (interviewing, shadowing and observations, empirical literature (knowledge) and quantitative/experimental methods (physical, mechanical, morphology testing) were employed for use.

Rehabilitation of patients in resource limited countries requires a multifactorial approach. Results of this study created a prioritised design specification and requirements guideline which revealed material longevity, colour stability and UV radiation resistance as crucial factors in resource limited areas. Also, the usage of locally sourced, naturally occurring cleanser solutions was explored. Simulating a year of usage of cleaning the prostheses indicated that hardness and elongation varied significantly over the period, whilst tear and tensile strength did not.

Furthermore, some of the identified candidate materials namely silicone, polyurethane and latex were established as possible prostheses materials in these regions. Change in colour variables ∆E, ∆L ∆A and ∆B under UV and outdoor irradiation revealed statistically significant changes in colour. Meanwhile, tear strength of the irradiated materials revealed significance for UV irradiated latex whilst all other samples were not significant. Yet, changes in tensile strength in both latex and polyurethane outdoor irradiated samples were not statistically significant whereas all the other sample groups showed significant changes. Further, elongation of the outdoor exposed polyurethane samples was not statistically significant whereas all other samples revealed statistically significant.

Overall, this study resulted in the collation and compilation of specification and requirements for maxillofacial prostheses development and proved the effectiveness and suitability of phytotherapy based antimicrobial cleansers. Additionally, identified candidate materials provided insight into possibly varied approaches to the provision of maxillofacial prostheses based on local needs and resources as opposed to normal known standards.