Hyperbaric oxygen treatment of unexpected mandibular bone necrosis after orthognathic surgery in a patient with hemifacial microsomia

Abstract

Hemifacial microsomia is a congenital disorder occurring in 1:5600, characterized by unilateral underdevelopment of the lower half of the face. It is primarily a syndrome of the first branchial arch. Patients with first branchial arch syndromes may also have cardiovascular defects. A 23-year-old female patient with hemifacial microsomia had undergone surgery, with the purpose of correcting her dental occlusion and to diminish snoring and facilitate breathing. After orthodontic correction, osteotomies of the maxilla and mandibula were planned. Shortly before the planned surgery, the patient experienced apoplexia. The patient underwent Le Fort I osteotomia and insertion of osteosynthesis plates. Two months after surgery, the occlusion was altered, indicating a dislocation of the osteosynthesis material and mandibular fracture, which was confirmed radiologically. During the following replacement of osteosynthesis material, the lateral part of the mandibular cortex showed comprehensive necrosis, and a large sequestrum was removed. Some weeks later, a large skin necrosis developed adjacent to the extaoral incision, and the patient was referred to the HBO unit. The patient was then treated with 28 hyperbaric oxygen exposures. After hyperbaric treatment, the patient healed completely. At a surgical intervention more than 1 year later, the osteosynthesis material was still osseointegrated. Although insufficient vascularity and consequent necrosis may not be expected in the mandible of a patient with hemifacial microsomia, attention should be drawn to the fact that facial vessels may also be underdeveloped. Hyperbaric oxygen may be considered as a treatment option in similar cases.