Outcomes of Facial Symmetry and Tone at Rest After Masseteric-to-Facial Nerve Transfer

Abstract

Importance: Masseteric-to-facial nerve transfer has gained popularity as a technique that provides dynamic voluntary function in unilateral facial paralysis. Despite the multiple studies that have demonstrated its efficiency in restoring dynamic facial function, there is a paucity of data on the effects on facial symmetry and tone at rest. Objective: To evaluate facial symmetry and tone at rest after masseteric-to-facial nerve transfer in patients with unilateral facial paralysis. Design, Setting, and Participants: This is a retrospective review of patients undergoing masseteric-to-facial nerve transfer for unilateral facial nerve paralysis at a tertiary academic center from 2012 to 2016. Patient demographics, etiology and duration of facial nerve paralysis, intervention, and the electronic Facial Assessment by Computer Evaluation (eFACE) scores were analyzed. Intervention: Masseteric-to-facial nerve transfer. Main Outcomes and Measures: Resting facial symmetry and tone was graded preoperatively and postoperatively using eFACE. Results: The study included 11 patients with complete unilateral facial paralysis treated with masseteric-to-facial nerve transfer from 2012 to 2016. Postoperative eFACE scores across the dynamic midface and smile scores demonstrated a statistically significant increase compared with preoperative eFACE scores (p < 0.001). There was no statistically significant difference found between preoperative and postoperative static midface and smile eFACE scores. Conclusions: Masseteric-to-facial nerve transfer has demonstrated promising results in restoration of voluntary smile. However, it has little to no effect on resting facial symmetry and tone.