Treatment of micrognathia with edentulous maxilla by sagittal split mandibular osteotomy and a subperiosteal implant immobilized with transmaxillary screws.

: Micrognathia complicated by edentulous maxilla was treated by performing sagittal-split mandibular osteotomy and immobilizing a subperiosteal implant using transmaxillary screws. The patient was a 42-year-old man who had a birdlike facial deformity caused by significant hypoplasia of the mandible. He also demonstrated significant malocclusion attributable to micrognathia and edentulous maxilla caused by resorption of the alveolar bone. These conditions impaired his mastication and articulation, making it impossible for him to eat regular food or carry out normal conversation. A subperiosteal implant was placed on the edentulous maxilla, and was rigidly immobilized to the maxilla using five transmaxillary screws. A prosthesis was then attached to the implant, and by using the implant as the point of reference and the anchor, the mandible was moved forward by sagittal-split mandibular osteotomy. Intermaxillary fixation was subsequently performed. The postoperative course has been favorable, and his facial complexion has improved significantly. One and a half years after his surgery, there has been no sign of complications or malocclusion caused by mandibular retraction. He is now able to eat regular food and speak normally.