# Synergistic Triad of Mixed Reality, 3D Printing, and Navigation in Complex Craniomaxillofacial Reconstruction

## TL;DR

A new approach using mixed reality, 3D printing, and navigation improves precision in complex facial reconstructive surgery.

## Contribution

Integration of mixed reality, 3D-printed models, and navigation for enhanced predictability in complex craniofacial surgery.

## Key findings

- Mixed reality glasses projected holograms to guide osteotomy line marking with good concordance to conventional navigation.
- 3D-printed skull models aided in dissection and removal of bony spicules during surgery.
- Postoperative outcomes showed successful re-established occlusion and closure of the maxillary alveolar gap.

## Abstract

The craniofacial skeleton is a complex three-dimensional structure, and major reconstructive cases remain challenging. We describe a synergistic approach combining intra-operative navigation, three-dimensionally (3D) printed skull models, and mixed reality (MR) to improve predictability in surgical outcomes. A patient with previously repaired bilateral cleft lip and palate, significant midfacial retrusion, and a large maxillary alveolar gap underwent segmental Le Fort I osteotomy and advancement. Preoperative virtual planning was performed, and reference templates were uploaded onto MR glasses. Intra-operatively, the MR glasses projected the templates as holograms onto the patient’s skull, guiding osteotomy line marking and validating bony segment movement, which was confirmed with conventional navigation. The 3D-printed skull model facilitated dissection and removal of intervening bony spicules. Preoperative planning proceeded seamlessly across software platforms. Osteotomy lines marked with MR showed good concordance with conventional navigation, and final segment positioning was accurately validated. Postoperative outcomes were satisfactory, with re-established occlusion and closure of the maxillary alveolar gap. The combined use of conventional navigation, 3D-printed models, and MR is feasible and allows safe integration of MR into complex craniofacial reconstruction while further validation of the technology is ongoing.