SMAS fold flap and allograft dermal matrix repairing parotid bed following parotidectomy to prevent facial deformity and Frey's syndrome

This study evaluates the outcome of superficial musculoaponeurotic system (SMAS) and allograft dermal matrix (ADM) preventing facial deformity and Frey's syndrome following total parotidectomy. Forty-six patients with benign parotid tumors, who underwent a total parotidectomy, were randomly assigned to four groups. Control group consisted of 12 patients; AMD group consisted of 10 patients underwent intraoperative placement of ADM within the parotid bed; SMAS group consisted of 11 patients underwent SMAS fold flaps repairing parotid bed; and SMAS plus AMD group consisted of 13 patients underwent intraoperative placement of ADM within the parotid bed and repairing parotid bed with SMAS fold flaps. Twelve months of follow-up was taken after the treatment, the rates of satisfaction with the post-operative facial contour were 33.3%, 40.0%, 91.9% and 100% respectively in the control group, AMD group, SMAS group and SMAS plus AMD group, and the difference between the SMAS plus AMD group and the former two groups was statistically significant (P < 0.05). The incidences of objective Frey's syndrome by modified Minor's Starch–Iodine Test were 50.0%, 20.0%, 27.3% and 7.7% respectively, and the difference between the SMAS plus AMD group and the control groups was statistically significant (P < 0.05). The SMAS fold flap is clinically simple to perform and prevent depressed facial deformity and a combination of SMAS fold flap and ADM can reduce obviously the incidence of Frey's syndrome in patients undergoing total parotidectomy.