3D-Printing of retainer for post-otoplasty morphology preservation

Congenital external auricular anomalies necessitate surgical correction for normal ear appearance. Despite high success rates, recurrence is common due to the elasticity of ear cartilage. Postoperative support and stress on the anatomical structures can effectively maintain the surgical results. This study aims to develop a personalized, 3D-printed retainer for post-otoplasty support, utilizing structured light-scanning and stereolithography 3D printing to improve postoperative outcomes with greater accuracy and consistency. Retainers were designed using Rhinoceros software to fit and support the ear based on these models. BioMed Flex 80A Resin was employed for 3D printing the retainers, ensuring biocompatibility and mechanical strength. Mechanical testing was conducted to assess the cured resins tensile and compressive properties, as well as its stress relaxation behavior. Finite element analysis (FEA) was performed to assess stress distribution and deformation for optimal support. Clinical validation was conducted involving 20 patients wearing the retainer for 8 h daily for a week, with satisfaction measured using the C-QUEST 2.0 scale. Clinical assessments were performed with 20 post-otoplasty patients treated with either a retainer or an external stretching device. The results indicated that high-precision, biocompatible, patient-specific retainers were successfully produced. BioMed Flex 80A Resin demonstrated strong performance under strain and good stress retention. FEA indicated uniform stress distribution and effective support in critical areas, ensuring structural stability. Clinical validation reported high satisfaction rates (85%), with minor issues in comfort and weight, suggesting a need for individualized adjustments. Clinical assessments demonstrated superior performance in maintaining auricular width and helix-mastoid (H-M) distance compared to the external stretching device. The personalized 3D-printed retainer offers a promising solution for post-otoplasty support, providing consistent, effective, and biocompatible results.