Functional and Aesthetic Assessment of Facial Reanimation with Free Gracilis Flap Transfer in Chronic Facial Paralysis.

INTRODUCTION: Chronic facial paralysis severely compromises facial symmetry and function. The free gracilis muscle flap has become the gold standard for dynamic facial reanimation. This study aims to evaluate the functional and aesthetic outcomes of gracilis free muscle flap procedures performed at the Facial Paralysis Clinic of Hospital General "Dr. Manuel Gea González," using the Terzis Functional Grading System and the eFACE (Electronic Facial Paralysis Assessment) digital assessment tool. MATERIALS AND METHODS: A retrospective, cross-sectional, and analytical study was conducted on 52 patients who underwent free gracilis muscle flap surgery for facial reanimation between 2018 and 2023. Inclusion criteria were chronic facial paralysis and complete pre- and postoperative assessments using the Terzis grading system. In unilateral cases, the eFACE scale was also used. Functional and aesthetic outcomes were analyzed using paired Student's t -tests. RESULTS: Of the 52 procedures, 62% involved unilateral paralysis. The most common etiology was classic Moebius syndrome (35%). Significant functional improvement was observed on the Terzis scale, with mean scores increasing from 1.1 to 3.1 postoperatively ( p  < 0.01). In unilateral cases, the eFACE scale demonstrated significant improvements in static symmetry, dynamic movement, midface/smile, and lower face/neck domains. No significant changes were observed in synkinesis or periocular function. Postoperatively, 52% of patients achieved good outcomes (group IV), and 86% of procedures were free of complications. CONCLUSION: The free gracilis muscle flap significantly improves facial function and aesthetic in patients with chronic facial paralysis. These findings validate its effectiveness and highlight the value of objective assessment tools for outcome measurement and future research.