The Treatment of Facial Asymmetry with Botulinum Toxin: Current Concepts, Guidelines, and Future Trends

Abstract

This article will describe facial asymmetry secondary to facial nerve paralysis (FNP), and review current concepts, guidelines, and future trends. Despite the increasing use of botulinum toxin (BoNTA) in treating FNP, ideal dosage, timing, and additional therapies are not unequivocally established. Facial asymmetry significantly impacts quality of life (QOL) by strongly affecting self-perception and social interactions; injectables may mediate great clinical improvement. This article provides practical guidelines for the use of BoNTA and provides schemes for accurate assessment and documentation. A systematic, stepwise approach is recommended with methodical assessment, meticulous placement, conservative dosage, and careful follow-up. Future trends include the potential use of newly developed toxins, muscle modification with fillers, improved imaging techniques, and targeted QOL studies. Hopefully, a growing number of aesthetic injectors may become technically proficient and join multidisciplinary teams for managing FNP.

Botulinum Toxin Type A: Adverse Events and Management

“…Selecting asymmetric injection points or different doses between the two face sides is the cause of this problem in subjects without pre-existing asymmetries. 23 Conversely, in subjects without pre-existing asymmetries, the problem is fine-tuning the differences in injected units to modulate the differential muscle contraction between the two face sides. The precondition to correct induced asymmetries is to identify the muscle sections with some residual contractile activity and inject about two units in the target area, with some variations according to the specific situation.…”

Assimetria labial: uma correção local apenas?

“…Uma boa harmonia e simetria facial se mostra como um caminho para boas relações entre os indivíduos e melhor qualidade de vida (Heydenrich, 2020). Contudo, deve-se observar o grau da desarmonia facial, quando existente, e considerar os possíveis futuros problemas estéticos e funcionais que podem surgir ao longo da vida (Kobus, Kobus-Zalésna, 2017;Medeiros et al, 2020).…”

Botulinum Toxin Type A to Improve Facial Symmetry in Facial Palsy: A Practical Guideline and Clinical Experience

“…Regardless of its etiology, idiopathic (Bell’s Palsy) or secondary facial nerve palsy, due to multiple etiologies such as Ramsey Hunt syndrome, infection, vascular, tumor resection and base of skull injuries, among others, manifests a unilateral peripheral facial nerve palsy which may lead to involuntary static and dynamic alterations of facial expression due to aberrant regeneration of fibers in the neural repair process in as many as 55.5% of patients with longstanding facial weakness [ 1 , 2 , 3 , 4 , 5 ]. The imbalance, static and dynamic, resulting from the muscular paralysis may not only jeopardize simple daily tasks such as articulation, eating and drinking, but is often cosmetically unacceptable to patients due to asymmetry, rendering psychological consequences such as low self-esteem, social isolation, anxiety, and depression [ 6 , 7 ].…”