Surgical Treatment and Botulinum Toxin Type A for the Management of Facial Synkinesis: A Systematic Review

Why clinicians should know about it

• Picked for Plastic and Reconstructive Surgery (paper of the day, 9 November 2026): Systematic review compares facial synkinesis surgery and botulinum toxin

Abstract

BACKGROUND: Facial synkinesis is a common sequela of peripheral facial nerve paralysis that affects facial function and aesthetics. Management options predominantly include botulinum toxin type A (BTX-A) injections and several surgical procedures. However, rather than viewing them as mutually exclusive therapies, the complementary roles of these approaches across the disease severity spectrum require clarification. This study aimed to systematically review the available evidence on BTX-A and surgical interventions for facial synkinesis. METHODS: A systematic review was conducted in accordance with PRISMA guidelines. PubMed, WoS, Scopus, and the Cochrane Library were searched to identify studies evaluating BTX-A or surgical treatment for facial synkinesis. Study selection and data extraction were independently performed by two reviewers. Risk of bias was assessed using the Joanna Briggs Institute (JBI) critical appraisal tools, and the certainty of evidence was evaluated using the GRADE approach. Due to substantial clinical heterogeneity and inherent confounding by indication between patient cohorts, a structured narrative synthesis was performed. RESULTS: Twenty-four studies met the inclusion criteria: 11 evaluating BTX-A, 11 assessing surgical interventions, and 2 investigating multimodal approaches. BTX-A injections improved synkinetic movements and facial symmetry with a favorable safety profile, although repeated treatments were required. Surgical procedures, such as selective neurectomy and myectomy, provided durable, structural improvements in patients with severe or refractory synkinesis. The overall certainty of evidence for comparative outcomes was rated as low to very low, largely due to indirect comparisons and baseline differences in disease severity among the treatment groups. CONCLUSIONS: BTX-A and surgical interventions should be viewed as complementary tools within a stepwise treatment algorithm rather than competing modalities. While BTX-A provides a minimally invasive option for mild-to-moderate cases, surgery offers long-lasting improvements for severe or refractory synkinesis. Furthermore, surgery can act synergistically in selected patients, modifying the aberrant neural structure to effectively reduce the dose and frequency of subsequent BTX-A requirements. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

Abstract as published, via PubMed.