Peripheral facial palsy after bilateral sagittal split ramus osteotomy: case report.

Bilateral sagittal split ramus osteotomy (BSSRO) is commonly used in orthognathic surgery. Although abnormal sensation in areas that are innervated by the inferior alveolar nerve is a well-known neurological complication of mandibular osteotomy, facial palsy is rare postoperatively. We present a case of peripheral facial palsy that developed the day after BSSRO to correct a mandibular protrusion in a 42-year-old man. Oral prednisolone was begun on the second day postoperatively, and was gradually tapered off over time. One month after operation, he had gradually recovered all movements in his right facial muscle and, after two months, had completely recovered without residual asymmetry. Possible causes of the palsy were compression of the facial nerve as a result of the insertion of a retractor around the posterior border of the ramus, and postoperative oedema. Peripheral facial palsy after BSSRO should be considered a rare, but possible, complication and as such, should be mentioned in consent forms.