Abstract: PURPOSE: To evaluate the role of eletroneurography(ENoG) and surface-electromyography(sEMG) in facial nerve function assessment, and provide experimental parameters for facial paralysis classification. METHODS: Regional House-Brackmann (HB) grading system and ENoG\sEMG were applied to evaluate iatrogenic injure degree of facial nerve caused by parotid gland surgery. ENoG was applied to 50 patients with unilateral parotid gland tumor before operation and 30 days postoperatively. Parameters including amplitude (Am) and motor unit action potential (MUAP) were recorded, and degeneration rate (DR) and inter-pulse interval (IPI) were calculated. At the same time, regional HB grading system evaluation classifications of patients were recorded. SPSS 20.0 software package was used to analyze the data. RESULTS: After surgery, the parameter of Am was lower in the affected side than healthy side, and the difference was significant（P<0.05）. The lower the level of facial nerve function evaluated by regional HB grading system, the smaller the DR value. Meanwhile, MUAP and IPI parameters between the healthy and affected sides had significant difference in Ⅳ-Ⅴ levels compared to parameters before operation（P<0.05）. CONCLUSIONS: Am and DR parameters acquired by ENoG can be used as objective parameters in facial nerve functional estimating system. Application of parameters acquired by sEMG need to be further studied in estimating facial nerve function.

Key words: Parotid gland surgery, Facial nerve function, Electroneurography, Surface-electromyography