Facial nerve grading after parotidectomy

Dysfunction of the facial nerve is a common complication of parotidectomy. The functional deficit may be total or partial, and may include all or a single branch of the nerve. Despite a wide variety of the facial nerve grading systems, most of them have a limited utility in patients after parotidectomy. Therefore, existing scales assessing facial nerve function are compared to describe facial nerve outcomes after parotidectomy. The regional House-Brackmann, Sydney, and Yanagihara classification systems were utilized. The post-parotidectomy facial nerve grading system (PPFNGS) was created based on these three grading systems and also used for this study. The facial nerve function was assessed and recorded on the first postoperative day following conservative parotidectomy in 200 patients using all 4 scales by 3 otolaryngologists. The validity of the PPFNGS and existing facial nerve grading systems was examined by assessment of interrater agreement, intraclass correlation coefficient, internal consistency and construct validity. A deficit in the facial nerve function was found in 54 patients (27 %). Although results were consistent in all tested scales, the PPFNGS had a higher interrater agreement than the other three scales. PPFNGS is a new grading system designed for assessing the facial nerve function after parotidectomy in a quantitative and qualitative way and has a higher interrater agreement than other scales used to examine function of the 7th nerve.