Navigation surgery for Le Fort 1 osteotomy in a fibrous dysplasia patient.

Orthognathic surgery is sometimes performed for fibrous dysplasia to correct malocclusion or facial asymmetry. However, Le Fort 1 osteotomy for this disease is difficult because of severe anatomical abnormality. Computer-assisted surgery is a rapidly developing technique in oral and maxillofacial surgery that is helping to ensure the safety of the surgery. We report a case of polyostotic craniofacial fibrous dysplasia in which two-jaw orthognathic surgery was performed using a navigation system with the Le Fort 1 osteotomy procedure. A 29-year-old woman presented with swelling and asymmetry on the right side of her face. Craniofacial fibrous dysplasia on the right side had been previously diagnosed, and she had undergone conservative surgery several times before. The disease extended to the right mandible, maxilla, and zygomatic, temporal frontal, and orbital areas, including the skull base. We first performed conservative contouring around the frontal and orbital areas, and then Le Fort I osteotomy and sagittal split ramus osteotomy to correct the asymmetry and cant of the occlusal plane. A passive infrared navigation system (Vector Vision surgical navigation system) was used for the Le Fort I osteotomy. The postoperative course was stable, and the facial asymmetry and cant of the occlusal plane improved and remained suitable 2 years after surgery. Thus, Le Fort 1 osteotomy can be performed safely in fibrous dysplasia with the aid of a passive infrared navigation system.