Mid-Term Effects of Selective Denervation Surgery on Facial Symmetry in Patients with Nonflaccid Facial Paralysis: Intermediate Follow-Up of Rest and Smile Symmetry

Abstract

Introduction: Although selective denervation (SD) improves clinician-graded, objective, and patient-reported smile symmetry, changes in resting symmetry have not been comprehensively studied. Objective: To assess mid-term changes in resting facial symmetry after SD, and to evaluate changes in perceived emotions in faces at rest and with smiling. Methods: Nonflaccid facial paralysis (NFFP) patients undergoing SD were studied from September 2021 to October 2022. Patient-reported, clinician-graded, and objective metrics of resting and smile symmetry were quantified. Results: Fourteen patients (median age 59.5 years; median paralysis duration 76.5 months; median follow-up 249.5 days (138-400); average of 5.7 branches sacrificed) underwent SD. Resting oral commissure (OC) symmetry (p = 0.028) and upper lip symmetry (p = 0.030) improved after surgery. In smiling faces, OC excursion (p = 0.004), smile angle (p = 0.016), and dental show (p = 0.012) improved. There were significant increases in perceived happiness at rest (p = 0.006) and with smile (p = 0.002). Clinician grading revealed improved nasolabial fold depth at rest (p = 0.087) after surgery, and patients reported improved facial function and happiness with the decision to undergo surgery. Conclusion: Intermediate follow-up suggests SD can improve objective resting and smile symmetry in patients with NFFP. After surgery, patients' faces convey more happiness in repose and with smile.