顎矯正手術を行った筋緊張性ジストロフィーに伴う顎変形症の1例

抄録

Myotonic dystrophy (MyD) is a rare genetic disease characterized by myotonia and muscular atrophy; it is often accompanied by jaw deformity. Orthognathic surgery for MyD has the following disadvantages: various complications can easily occur during general anesthesia, and postoperative mandibular relapse can be caused by masticatory muscle atrophy. We report a case of jaw deformity with MyD treated by orthognathic surgery. A 15-year-old boy visited our department because of abnormal occlusion; mandibular protrusion with anterior open bite was diagnosed. The presence of certain characteristic physical features and the results of genetic examinations led to the diagnosis of MyD. At 18 years of age, he underwent sagittal splitting ramus osteotomy with overcorrection, performed with the patient under general anesthesia in cooperation with related departments. Postoperative intermaxillary fixation was continued for 14 days. The occlusion temporarily stabilized, but a slight anterior open bite appeared 3 months after surgery; therefore, intermaxillary elastic traction was continued for 1.5 years. He has been followed up for 2 years 4 months after surgery, and no relapse has occurred.