Pursuing Mirror Image Reconstruction in Unilateral Microtia: Customizing Auricular Framework by Application of Three-Dimensional Imaging and Three-Dimensional Printing

Introduction

The advances in three-dimensional imaging and three-dimensional printing technology have expanded the frontier of presurgical design for microtia reconstruction from two-dimensional curved lines to three-dimensional perspectives. The auricular framework can now be customized precisely based on the three-dimensional mirror image of the normal ear in unilateral microtic patients as never before. This study presented the algorithm combining the three-dimensional surface imaging, computer-assisted design, and three-dimensional printing to create patient-specific auricular frameworks in unilateral microtia reconstruction.

Methods

Patients with unilateral microtia underwent auricular reconstruction with MEDPOR^® implant were enrolled in the study. Three-dimensional imaging of each patient’s head was captured by 3dMDcranial^® system and converted to a virtual solid for fabrication of the auricular template. For microtia reconstruction, the use of 3dMDcranial^® in measurement of ear anthropometry have been proved accurate and reproducible.¹Geomagic® Freeform® software and Touch™ X Haptic device were used for virtual sculpture. Extraneous artifacts were removed and soft tissue thickness was subtracted from the model. The template configurations were tailored to each patient’s unique auricular morphology. The final construct was mirrored to the defect side and the template was printed out of biocompatible acrylic.

Results:

During the surgery, the prefabricated customized template served as a three-dimensional guide for surgical simulation and sculpture of MEDPOR^®framework. The templates were used to simulate the appearance after skin draping and helped the surgeon to determine the appropriateness of soft tissue coverage. The implantable frameworks were carved from the MEDPOR^® block. The malleability of MEDPOR^®allowed mirror image-based replication of the intricate convolutions of the patient's auricle. Symmetrical and good aesthetic results regarding auricular shape, projection, and orientation can be obtained using this method.

Conclusion:

The combination of three-dimensional imaging and manufacturing technology with the malleability of MEDPOR^® has surpassed previous limitations resulted from autologous materials and ambiguity of two-dimensional planning. This approach allowed surgeons to build a customized auricular framework in a highly precise and sophisticated manner, moving a big step closer to the goal of mirror-image reconstruction for unilateral microtia patients.