*Comprehensive Rehabilitation of Patients with Facial Expression Asymmetry and Synkinesis… DOI: http://dx.doi.org/10.5772/intechopen.106694*

Facial Nerve Granding Sale scale (1985), which consists of six levels. The first level corresponds to the normal function of the facial nerve, and the sixth level corresponds to its complete dysfunction. Static asymmetry was assessed by the displacement of the denervated muscles in relation to the central line due to the traction of the muscles of facial expression of the unaffected hemiface. Dynamic asymmetry was assessed according to several criteria: blinking frequency (video recording was made during a conversation with a doctor), muscle activity during articulation, and facial expression tests. Clinically, in all patients on the side of the lesion, there were observed narrowing of the palpebral fissure, shortening of the zygomatic and buccal muscles, drooping of the ala of the nose, mouth angle, nasal tip deviation, and displacement of the midline of the lips toward the lesion.

### *2.1.1 Method of administration of botulinum toxin type A in facial expression asymmetry*

To correct (weaken) the pulling effect of the active muscles of the "healthy" hemiface, we perform sequential injections of the frontal, glabellar, periorbital areas, the nasal bridge, the nasolabial fold, the middle of the face, the perioral area, and chin on one side of the face. The target muscles are determined by the facial expression tests (to raise your eyebrows up, to frown, to squint, to "wrinkle" your nose, to show your teeth, to purse your lips). The most active areas of the muscles are injected. After applying local anesthesia and treating the skin with an antiseptic, the patient is given local injections of botulinum toxin type A.

The following treatment protocol was used: 100 units of botulinum toxin type A (botulinum toxin type A complex – hemagglutinin) is reconstituted with 2.0 ml of sodium chloride injection at a concentration of 9 mg/ml (0.9%). In this case, a reconstituted colorless solution is obtained with a concentration of 5 units in 0.1 ml. The solution is injected using a 1 ml syringe with a 30 G needle. In total, 1.25–2.5 units of the drug is injected into one injection point.

Subcutaneous injections are administered in the following areas of the unaffected hemiface:


**Figure 1.** *Injection pattern of botulinum toxin type A in the frontal region.*

**Figure 2.** *Injection pattern of botulinum toxin type A in the glabellar region.*

The number of injected points on the face, on average, is 15–20. During the procedure, the patient sits on a chair, resting their head against the wall. Patients sign a voluntary informed consent for medical diagnostic and treatment procedures.

*Comprehensive Rehabilitation of Patients with Facial Expression Asymmetry and Synkinesis… DOI: http://dx.doi.org/10.5772/intechopen.106694*

**Figure 3.** *Injection pattern of botulinum toxin type A in the periorbital region.*

**Figure 4.** *Injection pattern of botulinum toxin type A in the midface.*

### *2.1.2 Results of botulinum toxin therapy on facial expression asymmetry*

Within 7–10 days after botulinum toxin type A injections, a muscle relaxant effect occurs as a reduction of muscle activity on the "healthy" hemiface and a decrease in the displacement of denervated muscles in relation to the central line of the face.

#### **Figure 5.**

*Injection pattern of botulinum toxin type A in the perioral region.*

Patients begin to notice a tendency of facial symmetry restoration and then a gradual activity in the denervated muscles. According to our observations, an earlier recovery is observed in the orbicularis oculi muscle, manifested in lagophthalmos regression, making it possible to close the eye, which in turn is important for the eyeball protection. Following, the activity of nasalis muscle and levator labii superioris muscle is restored. The asymmetry of the smile function is the latest to get restored, due to the slow recovery of the activity of the zygomaticus major and minor muscles and the orbicularis oris muscle.

Patients of group I showed the better recovery dynamic due to the treatment. Fourteen days after the injection of botulinum toxin type A, patients of group I showed the average decrease of score on the House-Brackmann scale by 1.85 times (p < 0.05), while in group II patients' score dropped only by 1.1 times (p > 0.05). After 1 month the improvement in patients of group I was 2.6 times (p < 0.05), and in group II it was 1.5 times (p < 0.05). The general condition of the facial muscles in patients of group I, assessed using the Sunnybrook Facial Grading System, was 3.0 times better than in patients of group II (p < 0.01). It is important to note that in all subscales (symmetry of rest, symmetry of voluntary movements, synkinesis), the indicators in patients of group I were better than in group II. The dynamics of symptoms of static and dynamic facial asymmetry was also more distinct in patients of group I. Patients of group II showed a less noticeable dynamics, which prompted repeated injections of botulinum toxin type A (every 3–4 months for 1–3 years). Normally, a single injection of botulinum toxin type A is sufficient for patients of group I. The ultimate effect is observed after 1 month after the injections. We observed that the muscles of the affected hemiface get restored well enough to begin to "pull" the muscles of the "healthy" hemiface, denervated by botulinum toxin, toward themselves, which is an important detail. In such a case, a temporary
