Treatment of mandibular retrognathia with unilateral temporomandibular joint ankylosis and skeletal deformity of the mandibular ramus using unilateral mandibular distraction osteogenesis

This case report describes the surgical orthodontic treatment of severely retrognathic mandible and mandibular deviation in a patient with a medical history of unilateral subcondylar fracture and temporomandibular joint (TMJ) ankylosis. Because of the severe skeletal deformity of the mandibular ramus on the side with the injury, it was impossible to perform the conventional sagittal split ramus osteotomy (SSRO) on the affected side for the correction of mandibular retrognathia. The patient was treated by Le Fort I osteotomy, mandibular distraction on the affected side, and SSRO on the unaffected side, simultaneously. After treatment, acceptable occlusion and facial esthetics were obtained, though retrognathic mandible and facial asymmetry still remained.