Abstract: Objective: To evaluate facial nerve injury of the anterograde exposing method and the retrograde exposing method of facial nerve in benign lesions of the parotid gland. The facial nerve function (ENoG) and the House-Brackmann (H-B) scale were used to evaluate the extent of the facial nerve injury. To investigate the pros and cons of two surgical methods and evaluate the applicative prospect of ENoG examination in prognosing the outcome of facial nerve injury. Methods: Included in this study were 36 patients with unilateral benign lesions of the parotid gland who were admitted to the Department of Stomatology of the First Hospital of Lanzhou University from April to May 2017. They all received parotidectomy by either anterograde or retrograde method of exposing facial nerve by the same surgeon. The extent of facial nerve injury was evaluated by ENoG and H-B scale, and the correlation between two evaluation methods was studied. Results: The incidence of facial paralysis and facial nerve recovery time were lower in the anterograde group than in the retrograde group. There was a correlation between subjective H-B scale and objective ENoG parameters. Conclusion: Parotidectomy by the anterograde method of exposing facial nerve is superior to the retrograde method with regard to the potentiality of facial nerve injury. It is suggested that ENGG should be introduced into facial nerve function evaluation system as an objective index for evaluating facial nerve injury.

Key words: Facial nerve anatomy, Facial nerve function, evaluation Electromyography