Computer-aided design and manufacturing construction of a surgical template for craniofacial implant positioning to support a definitive nasal prosthesis

Aim: To design a surgical template to guide the insertion of craniofacial implants for nasal prosthesis retention. Materials and methods: The planning of the implant position was obtained using software for virtual surgery; the positions were transferred to a free-form computer-aided design modeling software and used to design the surgical guides. A rapid prototyping system was used to 3D-print a three-part template: a helmet to support the others, a starting guide to mark the skin before flap elevation, and a surgical guide for bone drilling. An accuracy evaluation between the planned and the placed final position of each implant was carried out by measuring the inclination of the axis of the implant (angular deviation) and the position of the apex of the implant (deviation at apex). Results: The implant in the glabella differed in angulation by 7.78 degrees, while the two implants in the premaxilla differed by 1.86 and 4.55 degrees, respectively. The deviation values at the apex of the implants with respect to the planned position were 1.17 mm for the implant in the glabella and 2.81 and 3.39 mm, respectively, for those implanted in the maxilla. Conclusions: The protocol presented in this article may represent a viable way to position craniofacial implants for supporting nasal prostheses.