Botulinum toxin treatment in patients with facial synkinesis

Outcomes of Buccinator Treatment With Botulinum Toxin in Facial Synkinesis

Importance

The buccinator, despite being a prominent midface muscle, has been previously overlooked as a target in the treatment of facial synkinesis with botulinum toxin.

Objective

To evaluate outcomes of patients treated with botulinum toxin to the buccinator muscle in the setting of facial synkinesis.

Design, Setting, and Participants

Prospective cohort study of patients who underwent treatment for facial synkinesis with botulinum toxin over multiple treatment cycles during a 1-year period was carried out in a tertiary referral center.

Interventions

Botulinum toxin treatment of facial musculature, including treatment cycles with and without buccinator injections.

Main Outcomes and Measures

Subjective outcomes were evaluated using the Synkinesis Assessment Questionnaire (SAQ) prior to injection of botulinum toxin and 2 weeks after treatment. Outcomes of SAQ preinjection and postinjection scores were compared in patients who had at least 1 treatment cycle with and without buccinator injections. Subanalysis was performed on SAQ questions specific to buccinator function (facial tightness and lip movement).

Results

Of 84 patients who received botulinum toxin injections for facial synkinesis, 33 received injections into the buccinator muscle. Of the 33, 23 met inclusion criteria (19 [82.6%] women; mean [SD] age, 46 [10] years). These patients presented for 82 treatment visits, of which 44 (53.6%) involved buccinator injections and 38 (46.4%) were without buccinator injections. The most common etiology of facial paralysis included vestibular schwannoma (10 [43.5%] participants) and Bell Palsy (9 [39.1%] participants). All patients had improved posttreatment SAQ scores compared with prebotulinum scores regardless of buccinator treatment. Compared with treatment cycles in which the buccinator was not addressed, buccinator injections resulted in lower total postinjection SAQ scores (45.9; 95% CI, 38.8-46.8; vs 42.8; 95% CI, 41.3-50.4; P = .43) and greater differences in prebotox and postbotox injection outcomes (18; 95% CI, 16.2-21.8; vs 19; 95% CI, 14.2-21.8; P = .73). Subanalysis of buccinator-specific scores revealed significantly improved postbotox injection scores with the addition of buccinator injections (5.7; 95% CI, 5.0-6.4; vs 4.1; 95% CI, 3.7-4.6; P = .004) and this corresponded to greater differences between prebotulinum and postbotulinum injection scores (3.3; 95% CI, 2.7-3.9; vs 2.0; 95% CI, 1.4-2.6; P = .02). The duration of botulinum toxin effect was similar both with and without buccinator treatment (66.8; 95% CI, 61.7-69.6; vs 65.7; 95% CI, 62.5-71.1; P = .72).

Conclusions and Relevance

The buccinator is a symptomatic muscle in the facial synkinesis population. Treatment with botulinum toxin is safe, effective and significantly improves patient symptoms.

Level of Evidence

3.

The use of botulinum toxin in head and face medicine: an interdisciplinary field

Background

In this review article different interdisciplinary relevant applications of botulinum toxin type A (BTA) in the head and face region are demonstrated.

Patients with head and face disorders of different etiology often suffer from disorders concerning their musculature (example: synkinesis in mimic muscles) or gland-secretion.

This leads to many problems and reduces their quality of life. The application of BTA can improve movement disorders like blepharospasm, hemifacial spasm, synkinesis following defective healing of the facial nerve, palatal tremor, severe bruxism, oromandibular dystonias hypertrophy of the masseter muscle and disorders of the autonomous nerve system like hypersalivation, hyperlacrimation, pathological sweating and intrinsic rhinitis.

Conclusion

The application of botulinum toxin type A is a helpful and minimally invasive treatment option to improve the quality of life in patients with head and face disorders of different quality and etiology. Side effects are rare.

Noncosmetic uses of botulinum toxin

Since the introduction of botulinum toxin (BTX) as a therapeutic tool in the 1970s, the number of uses for this substance has increased exponentially. BTX's mechanism of action involves degrading the SNARE proteins blockading the release of acetylcholine into the neuromuscular junction. In many body systems, decrease of contractility, strength, and tension of certain muscle groups result in improved clinical outcomes. Applications now include cosmetic, gastroenterologic, otolaryngologic, genitourinary, neurologic, and dermatologic uses. In fact, BTX can be considered as a potential treatment in any situation involving inappropriate or exaggerated muscle contraction. Currently, the FDA has approved BTX-A (Botox) for treating glabellar lines, blepharospasm, strabismus, hemifacial spasm, cervical dystonia, and spasticity. With the addition of cosmetic applications to the FDA's approval list, the use of BTX has increased dramatically.

Up-to-date report of botulinum toxin type A treatment in patients with gustatory sweating (Frey's syndrome)

Several therapeutic approaches exist to treat gustatory sweating (Frey's syndrome) following parotidectomy. Because of the lack of effective treatment, a new therapeutic modality using botulinum toxin injections was presented previously by our group. The duration of the demonstrated positive effect was essentially unknown so far. Based on our experiences using this technique since December 1993, the purpose of this clinical investigation was to make an up-to-date report and demonstrate the duration of effect of BOTOX injections in patients with severe gustatory sweating. Nineteen patients with severe gustatory sweating have been treated with BOTOX by intracutaneous injections into the affected skin areas. The maximal follow-up time was 33 months. The results were obtained by interviews and controls using Minor's starch iodine test. In all treated cases (n = 19 patients, 22 treated sides) gustatory sweating ceased completely within 2 days. Side effects were absent. In 12 patients gustatory sweating reappeared. The mean duration of effect was 17.3 months (subjective personal communication of 18 patients). Findings show that intracutaneous injection of BOTOX is a highly effective, safe, and minimally invasive treatment of Frey's syndrome with long-lasting therapeutic effect.