Computer-aided design and manufacturing construction of a pilot guide for a bone-anchored epithesis to replace an absent pinna.

Bone-anchored epitheses have acquired an important role in auricle reconstruction. The purpose of this technical note is to present a fully in-house digital workflow for the design and three-dimensional (3D) printing of an optimal ear epithesis guide. Two hemifacial microsomia patients with grade IV microtia were treated accordingly. The upper dental arch was optically scanned and a cone beam computed tomography scan of the cranium was obtained. The composite and soft tissue models created were exported into 3D sculpting software. The unaffected ear was virtually mirrored onto the affected side and two ideal implant positions were defined in relation to bone thickness, contralateral symmetry, and housing of the retaining bar. A bite wafer was virtually designed on the upper dental arch and connected to the mirrored ear. The pilot guide was 3D-printed and allowed for correct positioning and orientation during surgery. The prosthetic pinna was manufactured in a conventional way. A bar with retaining clips was used to anchor the prosthetic pinna. Clinically satisfactory results were obtained in two grade IV microtia cases. The fully digital workflow presented to design and 3D-print an optimal ear epithesis guide offers a good alternative to the existing techniques.