Unusual late vascular complications of sagittal split osteotomy of the mandibular ramus.

Intraoperative or early postoperative vascular complications are not uncommon problems in sagittal split osteotomies of the mandibular ramus; however, reports of late complications are considerably rarer. Here, we present two patients who sustained late vascular complications after the sagittal split osteotomy. The first patient had a delayed bleeding, which presented itself as a rapidly expanding swelling of the left cheek from the left external carotid artery 18 days postoperatively. During exploration, a 2 mm laceration of the external carotid artery located just proximal to the bifurcation of the internal maxillary artery and the superficial temporal artery was successfully repaired. The prominent bony spike of the cut end of medial cortex of the set-back mandibular ramus was found against the arterial wall and could possibly have caused the progressive necrosis of the wall with subsequent spontaneous rupture. The second patient suffered from a mild noise in the right ear 2 weeks after the initial surgery; however, a pre-auricular arteriovenous fistula between the right external carotid artery and the external jugular vein was discovered 1 year postoperatively. The diagnosis was confirmed by angiography, and the lesion was treated successfully by therapeutic embolization at that time. To avoid vascular injury, sufficient protection of the soft tissue during exposure of the mandibular ramus is mandatory. In addition, the direction of the cut of medial cortex is suggested to avoid the cranialward inclination that creates a sharp, bony end against the artery. Awareness of the possible late vascular complications to facilitate early detection and management is also important.