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.