A novel dual-stage robotic-assisted surgical workflow for precision contouring of craniomaxillofacial fibrous dysplasia

BACKGROUND: Craniomaxillofacial fibrous dysplasia (FD) causes progressive facial asymmetry and deformity, while conventional contouring surgery remains limited by poor visibility and proximity to critical structures. This study proposes a novel dual-stage robotic-assisted workflow for precise and safe contouring of craniomaxillofacial FD. METHODS: The workflow comprised two stages: (1) robotic localization and depth-controlled drilling using a dentition-supported optical registration system for titanium screw placement, and (2) automated high-speed robotic contouring following the surgical plan. Postoperative accuracy was evaluated by comparing CT-based 3D models with planned models using root mean square deviation (RMSD) analysis. RESULTS: Five patients with craniomaxillofacial FD underwent robot-assisted contouring guided by virtual surgical planning. The lesions were located on the right side in two patients and on the left side in three patients. All surgeries were completed successfully according to the virtual plans, with no intraoperative or postoperative complications. Quantitative evaluation revealed a mean RMSD of 1.77 ± 0.58 mm (1.22–2.77 mm), indicating high consistency between planned and actual outcomes. The orbital rim and maxillary surfaces demonstrated the smallest deviations, confirming the accuracy of the robotic-guided resection. All patients exhibited notable improvement in facial symmetry and contour smoothness, and infraorbital nerve sensation recovered completely within 3 months. CONCLUSION: This study presents the first dual-stage robotic-assisted workflow for contouring craniomaxillofacial FD, integrating virtual planning, optical registration, and precision robotic trimming. The system achieved sub-2 mm accuracy and excellent aesthetic outcomes without complications, effectively overcoming the limitations of conventional techniques and representing a significant step toward automated, safe, and precise craniofacial contour surgery.