Comparative Efficacy of Masseteric-to-Facial Nerve Transfer With and Without Fascia Lata Grafts in Reanimating Facial Paralysis

Background: Masseteric-to-facial nerve transfer excels in dynamic reanimation but lacks in restoring baseline resting tone. Combining with fascia lata grafts is expected to more fully enhance facial symmetry. Comprehensive comparison of the results of masseteric-to-facial nerve transfer versus combined static suspension may providing valuable insights for patients with subacute facial paralysis to select the most appropriate treatment. Methods: In this retrospective study, 104 facial paralysis patients were categorized by surgical procedure: 39 received masseteric-to-facial nerve transfer (Group A) and 65 underwent combined with fascia lata graft (Group B), further divided by oral commissure drooping severity into slight (A 1 , B 1 ) and severe (A 2 , B 2 ) asymmetry. Results: Patients in Group B 2 exhibited significantly better static symmetry than those in Group A 2 , with improvements of 87.87% versus 40% (p < 0.001). No significant difference was observed in slight-asymmetry patients between Groups A 1 and B 1 . The Terzis Smile Function Grading System showed no dynamic symmetry differences (p > 0.05). For objective evaluation, postoperative outcomes indicated better static symmetry in both Group B, while Group A 1 showed improved dynamic symmetry, with no statistical difference between Groups A 2 and B 2 . Conclusions: Masseteric-to-facial nerve transfer combined with fascia lata grafts significantly enhanced both static and dynamic symmetry for patients with varying degree of asymmetry, particularly benefitting those with severe asymmetry. Patients with slight asymmetry who underwent the combined procedure achieved satisfactory static symmetry, although with a minor compromise of approximately 1mm in dynamic symmetry compared to those underwent masseteric-to-facial nerve transfer alone.