Clinical examination for benign parotid tumors arising from the deep lobe

—For postoperative facial paresis—

Abstract

Deep lobe parotid tumors are relatively rare. The incidence of facial nerve dysfunction following parotidectomy with these tumors is high and is associated with challenging surgical technique. We evaluated facial nerve function in 100 patients presenting between January 2006 and December 2008 with previously untreated benign parotid tumors who underwent parotidectomy (13 situated deep lobe of the parotid). The rate of postoperative facial nerve paresis of the 13 cases was 61.5% (8/13 cases), which was significantly higher than tumor cases located in the superficial lobe. In addition, all facial branches were more affected in patients with deep lobe tumors compared with patients with superficial lobe tumors. All patients who experienced postoperative facial nerve paresis showed full recovery within 3 weeks from 6 months. A mass size in excess of 40mm was associated with higher incidence of facial nerve paresis compared with the masses less than 40mm. Due to limitations on preoperative evaluation of tumor location, 4 of 13 cases with deep lobe tumors were preoperatively misdiagnosed as superficial lobe tumors.