**2. Comprehensive rehabilitation of patients with facial expression asymmetry**

### **2.1 The use of botulinum toxin type A in patients with facial expression asymmetry**

The main task of botulinum toxin therapy of facial expression asymmetry in neuropathy of the facial nerve is to influence the hypertonicity of the muscles of the healthy hemiface by muscle relaxation. The increased activity of the muscles of the contralateral (healthy) hemiface is considered to be a mechanism for pathological compensation of the functional motor deficit on the side of the lesion and may prevent or slow down the process of recovery of facial expression activity [1–4]. As a result of the treatment, after some time (10–14 days), we can observe how the affected muscles restore their functions. This contributes to the regression of facial expression asymmetry [1–4, 9]. We observed two groups of patients. In group I, there were patients in the acute phase of Bell's palsy (within 1 month after the onset of the disease), who deliberately refused corticosteroid therapy due to various reasons (diabetes mellitus, osteoporosis, poor tolerance to corticosteroids in history). Thus, monotherapy of Bell's palsy with botulinum toxin type A was carried out. Group II included patients with facial asymmetry in the late phase of Bell's palsy. The duration of the disease in this group of patients ranged from 3 months to 19 years.

The Sunnybrook Facial Grading Scale (SFGS) was used to assess facial symmetry and synkinesis, while the facial asymmetry was assessed using the House-Brackmann
