Recently, treatment for jaw deformities has diversified. This report describes the treatment and outcome of a patient who underwent hi-maxillary osteotomy aided by lateral expansion with midline distraction osteogenesis. The patient was a 31-year-old woman. She was given a diagnosis of mandibular prognathism with crowding of the anterior teeth and an extremely narrow hi-maxillary arch width. Procedures were used Le Fort I osteotomy and median palate osteotomy in the maxilla and sagittal split ramus osteotomy and a median osteotomy in the mandible. A rapid lateral expansion device was attached to the maxilla preoperatively and an original bone distraction device was attached to the mandible at the midline during operation. This device consisted of two intermaxillary fixation screws, serving as anchors for expansion. The maxilla was lengthened laterally by 5.5mm and the mandible by 4.5mm. Immediately after distraction was completed, orthodontic treatment was started, followed by periodontal treatment and prosthodontic treatment. One year after the operation, the patient has normal occlusion and is satisfied with the results.
