Modified technique to improve fabrication and outcome of definitive orbital prosthesis

Automated Noncontact Facial Topography Mapping, 3-Dimensional Printing, and Silicone Casting of Orbital Prosthesis

PURPOSE

A proof-of-concept workflow study for the fabrication of custom orbital exenteration prostheses via automated noncontact scanning, 3D printing, and silicone casting.

DESIGN

Noncomparative, interventional case series.

METHODS

Setting: Single-center institutional study. StudyPopulation: Three patients who have discontinued wearing of the ocularist-made exenteration prosthesis due to altered fit, discoloration, or material degradation. InterventionProcedure: A digital representation of the exenteration socket and contralateral periocular region was captured through noncontact facial topography mapping. Digital construction of the anterior prosthesis surface was based on the mirrored image of the contralateral side, and the posterior surface contour was based on orbital cavity geometry. The anterior and posterior surface details were digitally merged. A 2-piece mold was designed and produced in a 3D printer. Colorimetry was used to create a custom blend of pigments for incorporation into the Shore 40 silicone elastomer to generate a prosthesis that approximates the patient's skin tone. MainOutcomeMeasures: Prosthesis symmetry, skin tone match, comfort of wear, and appearance.

RESULTS

The first copy of every 3D-printed orbital prosthesis using this fabrication workflow produced good symmetry, color match, and prosthesis fit. In one case, the recontoured second copy with improved prosthesis edge-to-skin interface was made without the patient present.

CONCLUSION

A noncontact 3D scanning, computer-aided design, 3D printing, and silicone casting for fabrication of orbital prosthesis was developed and validated. This production workflow has the potential to provide an efficient, standardized, reproducible exenteration prosthesis and to overcome the principal barriers to an affordable custom prosthesis worldwide: access and cost.

Novel artificial eye service evaluation using patient reported outcome measures

BACKGROUND

This service evaluation explores patient reported outcomes from patients provided with high definition ocular prostheses (artificial eyes).

METHODS

Validated patient questionnaires (FACE-Q, DAS24 and HADS) were utilised to evaluate patient experiences of their new ocular prosthesis. 10 patients were included in the service evaluation, which was conducted between December 2018 and September 2019. Descriptive analysis of the mean and 95% CI was undertaken for all questionnaires. Statistical analysis was performed using SPSS 21 Principal Component Analysis (PCA) for FACE-Q questionnaires. Correlations were significant when factor loading is at α > 0.4.

RESULTS

A questionnaire response rate of 80% was achieved (n = 8). PCA analysis showed the number of variables tested could be reduced. Two principal components (PC1 and PC2) had very good to excellent internal consistency between variables with factor loading (α = 0.7-0.9). PC1 contained questionnaires 1-7, all of which were highly correlated. PC2 contained question number 8 with a factor loading of α = 0.8. This indicates good reliability, validity and responsiveness.

CONCLUSIONS

We hope to demonstrate the importance of service evaluations with respect to rapidly evolving technological advances in medical devices, pharmaceuticals and imaging modalities. Further feasibility and full clinical studies are required to confirm the positive results of the novel artificial eye service we have evaluated with respect to the traditional approach.

Past, Present, and Future of Soft-Tissue Prosthetics: Advanced Polymers and Advanced Manufacturing

Millions of people worldwide experience disfigurement due to cancers, congenital defects, or trauma, leading to significant psychological, social, and economic disadvantage. Prosthetics aim to reduce their suffering by restoring aesthetics and function using synthetic materials that mimic the characteristics of native tissue. In the 1900s, natural materials used for thousands of years in prosthetics were replaced by synthetic polymers bringing about significant improvements in fabrication and greater realism and utility. These traditional methods have now been disrupted by the advanced manufacturing revolution, radically changing the materials, methods, and nature of prosthetics. In this report, traditional synthetic polymers and advanced prosthetic materials and manufacturing techniques are discussed, including a focus on prosthetic material degradation. New manufacturing approaches and future technological developments are also discussed in the context of specific tissues requiring aesthetic restoration, such as ear, nose, face, eye, breast, and hand. As advanced manufacturing moves from research into clinical practice, prosthetics can begin new age to significantly improve the quality of life for those suffering tissue loss or disfigurement.

Advancements in Soft-Tissue Prosthetics Part B: The Chemistry of Imitating Life

Each year, congenital defects, trauma or cancer often results in considerable physical disfigurement for many people worldwide. This adversely impacts their psychological, social and economic outlook, leading to poor life experiences and negative health outcomes. In many cases of soft tissue disfigurement, highly personalized prostheses are available to restore both aesthetics and function. As discussed in part A of this review, key to the success of any soft tissue prosthetic is the fundamental properties of the materials. This determines the maximum attainable level of aesthetics, attachment mechanisms, fabrication complexity, cost, and robustness. Since the early-mid 20th century, polymers have completely replaced natural materials in prosthetics, with advances in both material properties and fabrication techniques leading to significantly improved capabilities. In part A, we discussed the history of polymers in prosthetics, their ideal properties, and the application of polymers in prostheses for the ear, nose, eye, breast and finger. We also reviewed the latest developments in advanced manufacturing and 3D printing, including different fabrication technologies and new and upcoming materials. In this review, Part B, we detail the chemistry of the most commonly used synthetic polymers in soft tissue prosthetics; silicone, acrylic resin, vinyl polymer, and polyurethane elastomer. For each polymer, we briefly discuss their history before detailing their chemistry and fabrication processes. We also discuss degradation of the polymer in the context of their application in prosthetics, including time and weathering, the impact of skin secretions, microbial growth and cleaning and disinfecting. Although advanced manufacturing promises new fabrication capabilities using exotic synthetic polymers with programmable material properties, silicones and acrylics remain the most commonly used materials in prosthetics today. As research in this field progresses, development of new variations and fabrication techniques based on these synthetic polymers will lead to even better and more robust soft tissue prosthetics, with improved life-like aesthetics and lower cost manufacturing.

Advancements in Soft-Tissue Prosthetics Part A: The Art of Imitating Life

Physical disfigurement due to congenital defects, trauma, or cancer causes considerable distress and physical impairment for millions of people worldwide; impacting their economic, psychological and social wellbeing. Since 3000 B.C., prosthetic devices have been used to address these issues by restoring both aesthetics and utility to those with disfigurement. Internationally, academic and industry researchers are constantly developing new materials and manufacturing techniques to provide higher quality and lower cost prostheses to those people who need them. New advanced technologies including 3D imaging, modeling, and printing are revolutionizing the way prostheses are now made. These new approaches are disrupting the traditional and manual art form of prosthetic production which are laborious and costly and are being replaced by more precise and quantitative processes which enable the rapid, low cost production of patient-specific prostheses. In this two part review, we provide a comprehensive report of past, present and emerging soft-tissue prosthetic materials and manufacturing techniques. In this review, part A, we examine, historically, the ideal properts of a polymeric material when applied in soft-tissue prosthetics. We also detail new research approaches to target specific tissues which commonly require aesthetic restoration (e.g. ear, nose and eyes) and discuss both traditional and advanced fabrication methods, from hand-crafted impression based approaches to advanced manufactured prosthetics. We discuss the chemistry and related details of most significant synthetic polymers used in soft-tissue prosthetics in Part B. As advanced manufacturing transitions from research into practice, the five millennia history of prosthetics enters a new age of economic, personalized, advanced soft tissue prosthetics and with this comes significantly improved quality of life for the people affected by tissue loss.