Role of Perinasal Musculature in Ipsilateral Nasal Obstruction During Synkinesis Progression

<b>Background:</b> Facial synkinesis can lead to unintended activation of perinasal muscles, contributing to dynamic nasal obstruction. <b>Objective:</b> To determine whether targeted botulinum toxin injections, compared to no treatment, reduce new ipsilateral nasal obstruction symptoms in patients with facial synkinesis, as measured by patient-reported outcomes and the Nasal Obstruction Symptom Evaluation (NOSE) scale. <b>Methods:</b> A retrospective review was conducted of patients presenting with ipsilateral nasal obstruction and synkinesis at a multidisciplinary facial nerve clinic. Botulinum toxin (2-2.5 units) was injected into the supra-alar nasalis and depressor septi muscles. Symptom improvement was assessed at 4 weeks using patient-reported outcomes and the NOSE scale. <b>Results:</b> Of 99 treated synkinetic patients, 23 (23.5%) reported new-onset nasal obstruction. Following chemodenervation, 74% experienced symptom relief, 4% had no improvement, and 22% were indeterminate. NOSE scores significantly improved from a mean of 44.86 to 28.93, with a mean difference of 15.93 (95% confidence interval: 2.86-29.00). <b>Conclusion:</b> Botulinum toxin injections targeting the perinasal musculature significantly improved nasal obstruction symptoms in patients with facial synkinesis.