A case of peripheral facial nerve palsy after orthognathic surgery in a patient with hemifacial microsomia

We report a case of peripheral facial palsy after orthognathic surgery in a patient with hemifacial microsomia (HFM). The patient was a 20-year-old woman with right HFM. CT examination revealed hypoplasia of the right mandibular ramus, condyle, maxilla, temporal bone, muscles of mastication and parotid salivary gland. She underwent Le Fort Ⅰ osteotomy and bilateral sagittal split ramus osteotomy. Two days after the operation, right facial nerve palsy appeared. Three months after the operation, the palsy was completely resolved by conservative therapy including pharmacotherapy, stellate ganglion blocks and physiotherapy. Facial nerve palsy might have been caused by nerve ischemia and mechanical damage indirect or direct compression from the distal segment, surgical instruments, edema and hematoma. Furthermore, in this case, it is possible that an underlying cause of facial palsy is hypoplasia of the retromandibular region surrounding the facial nerve associated with HMF.