*2.2.1 Method of implantation of monofilament mesothreads to treat synkinesis*

Monofilament mesothreads are among the minimally invasive rejuvenation procedures in esthetic medicine, which makes it possible to improve the involutional manifestations of aging. Mesothreads got this name due to their small diameter, comparable to the diameter of a needle for mesotherapy. These threads are used to modify

**Figure 24.** *Bell's palsy. Patient А. before injections.*

**Figure 25.** *Patient А., 1 month after injection.*

involutional changes in the skin and ptosis of the soft tissues of the face. The visible lifting effect of the soft tissues is determined by creation of a rigid frame consisting of a large number of mesothreads and new collagen fibers forming around them [17, 18]. Clinically, this is manifested by a decrease in the severity of wrinkles and folds and an increase in skin density and elasticity [17, 18]. Mesothreads are completely bioresorbable, often made from polydioxanone - a hypoallergenic, non-toxic material that undergoes biodegradation in 180–240 days, which gives a long-term preservation effect up to 1.5–2 years. Mesothreads are applied in different age groups. In patients

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

younger than 30 years old, it is used to prevent aging of the skin, in the older age groups, it is used to reposition the soft tissues of the face [17, 18].

There has been some data documented about the use of polydioxanone threads in combination with botulinum toxin injections for the treatment of the facial expression asymmetry [19]. The authors used the implantation of toothed threads in the subcutaneous plane along the intended trajectory in patients with unilateral sagging of the face in the late period of facial nerve neuropathy. The authors implanted patients with unilateral sagging of the face in the late period of facial nerve neuropathy with cogged threads in the subcutaneous layer along the planned trajectory. At the same time, local injections of botulinum toxin type A were performed to treat contralateral hypertrophy and ipsilateral synkinesis. As a result, the symmetry of the face got improved. Due to the lifting effect with the help of threads, there was a rejuvenation of the sagging hemiface observed, which occurs as a result of prolonged paralysis of the muscles of facial expression [19].

In our work, we used a completely different approach. We used smooth, monofilament threads (short 3–4 cm, non-cogged threads) in the affected hemiface to correct synkinesis.

The proposed method allows creating a rigid frame-mesh between the skin and muscles of facial expression, which helps to counteract their pathological contraction. The "target" for the implantation of threads is actively contracting muscle bundles. Usually, they are located in the periorbital region, along the nasolabial fold, in the projection of the modiolus and mentalis region. Synkinesis in the periorbital region manifests in muscle contractions in the infraorbital margin, the lateral part of the orbit, the superciliary arch (in the projection of corrugator muscle), as well as in the upper eyelid region. It is not possible to install threads in the upper eyelid region in the projection of levator palpebrae superioris muscle due to the high risk of thread displacement into the orbital region and muscle injury even when implanted superficially. Therefore, the use of mesothreads to treat synkinesis in the upper eyelid, inferior to the orbital rim, is impossible due to the high risk of complications. Threads are installed in the subcutaneous layer attached to the posterior layer of the dermis in the area of synkinesis, between the skin and muscles (**Figure 26**). The injection site for the introduction of the thread is at a distance of 2–3 cm in each direction from the synkinesis. The threads are implanted at a distance of 1–1.5 mm from each other and in the form of mutually intersecting lines (five threads horizontally and five threads perpendicular or at an angle). The crossing point of the threads should be in the zone of synkinesis (**Figure 27**). The thickness and length of the thread are selected depending on the area of treatment. The qualification and experience of a plastic surgeon who performs the implantation of mesothreads are key in the successful procedure. Patients were informed about ongoing medical diagnostic and treatment procedures. During the visit, each patient signed a voluntary informed consent.

#### *2.2.2 Results of treatment of synkinesis with monofilament mesothreads*

In patients of group I (who received botulinum toxin therapy), the effect appeared only 7–10 days after the administration of the drug. The amplitude and frequency of synkinesis in patients of group II (who were treated with mesothreads) decreased immediately after the completion of the procedure. A significant effect of implantation of mesothreads was also registered 7–10 days after the procedure. The amplitude and severity of synkinesis in the "u-e," "b-p" test significantly decreased. Patients noted that they managed to communicate with other people easily. The interlocutors stopped peering,

**Figure 26.** *Position of the threads for the treatment of synkinesis.*

#### **Figure 27.** *Potential areas for the implantation of monofilament mesothreads in the synkinesis region.*

trying to discern the involuntary movements of the muscles of the face in patients, which significantly increased patients' self-esteem, improved the quality of life.

In 1, 3, 6, and 12 months after the procedures, the general condition of the facial muscles of patients of group II, assessed using the SFGS scale, was 2.0, 2.3, 2.4, and 1.9 times better than in patients of group I (p < 0.01). In 50% of cases, the positive effect of mesothreads on synkinesis persisted even after 1.5–2 years.

Thus, a comparative analysis of two methods for treatment of motor synkinesis showed the best result in the group of patients who received monofilament mesothreads. We observed a significant decrease in the severity of clinical symptoms, manifested in a decrease of the frequency and amplitude of involuntary muscle contractions in the face.

The proposed method has limitation. It is likely to develop a hematoma at the injection sites of mesothreads (especially in the periorbital region). There is a risk of rejection of the threads within the first 2–3 days (due to the extremely superficial introduction). In such a case, it is important to remove the thread, holding it by the tip. It is likely to experience pain after thread implantation (within 1–2 days), as well as a relatively long rehabilitation period (up to 10 days).

In the later period (6–12 months), it is likely to have a migration of threads and the formation of a ligature fistula. There have been no such complications in our practice.

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