Motor Aberrant Reinnervation Sequelae in Postparalytic Facial Synkinesis: A 35-year Evolution of Surgical Strategy

In the face, motor aberrant reinnervation sequelae (MARS) manifests as postparalytic facial synkinesis (PPFS) following facial paralysis. Surgical treatment remains challenging and controversial, with no consensus.

This study investigated the personal evolution of surgical strategy over 35 years. Between 1995 and 2024, a total of 132 patients with MARS manifesting as PPFS were treated surgically. The cohort was divided into 2 periods: 1995-2020 (103 patients) and 2021-2024 (29 patients). The first surgical strategy was aggressive and unconventional, based on the hypothesis that regenerative but unnatural nerves and muscles must be selectively and aggressively removed to eliminate synkinesis first before any functional and aesthetic procedures. This was followed by rebuilding a new nerve muscle order to achieve a natural smile by using functioning free muscle transplantation innervated by other motor nerve transfer. The second surgical strategy was a refinement introduced in 2021 involving the use of dermal fat graft to prevent postoperative contracture.

The majority of patients (82%) underwent cross-face nerve graft-innervated gracilis transplantation. Quantitative assessments of smile excursion, cortical adaptation, and synkinesis grading showed statistically significant improvements (P < 0.05). The introduction of prophylactic dermal fat graft virtually eliminated the incidence of postoperative contracture of the upper lip and nasolabial fold.

The proposed aggressive surgical strategy for treating MARS manifesting as PPFS is proven correct, effective, and durable. By converting the neuromuscular landscape from a disorganized, synkinetic state to a reconstructed, independent system, patients achieve significant functional and aesthetic recovery.