Pseudoaneurysm of the superficial temporal artery after sagittal split ramus osteotomy: A case report.

Sagittal split ramus osteotomy (SSRO) is a widely performed orthognathic surgery; however, among the various reported complications of SSRO, pseudoaneurysms are rarely reported. Pseudoaneurysms are rare vascular lesions formed by damage to the arterial wall that can occur after trauma or postoperatively, causing uncontrolled bleeding. The present report describes a case of a pseudoaneurysm that occurred after SSRO in a 22-year-old female patient. Le Fort I osteotomy and bilateral SSRO were performed under general anesthesia to improve the gummy smile and mandibular asymmetry of the patient. While osteotomizing the medial side of the left SSRO, major bleeding occurred from the soft tissue of the posterior margin of the mandibular branch. Direct compression with gauze and a local hemostatic agent stopped the bleeding. Immediately after returning to the ward, bleeding was observed from the left wound site and marked swelling of the left buccal area occurred. Contrast-enhanced computed tomography revealed a pseudoaneurysm of the left superficial temporal artery (STA). Subsequently, arterial embolization for the pseudoaneurysm was performed. Overall, the present report describes a rare case of pseudoaneurysm of the STA as a postoperative complication of SSRO.