The uses of botulinum toxin A in facial aesthetics

Abstract

The demand for non-surgical facial rejuvenation procedures is rising, and they are more popular than ever, with the aesthetic uses of botulinum toxin dramatically changing the landscape of facial rejuvenation. Botulinum toxin is a neurotoxin that works within cholinergic synapses present at neuromuscular endplates, preventing the transmission of neurotransmitters, such as acetylcholine, from nerves to muscles. This interference with nerve impulses leads to the muscles being temporarily weakened (paralysis). Botulinum toxin A was approved by the US Food and Drug Administration (FDA) for use in the glabella in 2002, followed by crow's feet in 2013 and then the forehead in 2017, with other aesthetic uses being classed as off-license. Botulinum toxin A yields good results in carefully selected patients, and a thorough consultation should always take place. Consultations should include management of expectations and the explanation that botulinum toxin A works on dynamic lines, rather than static lines. Treatment areas can be split into the upper face (glabellar, transverse forehead lines and lateral orbicularis oculi); mid face (bunny lines and perioral vertical lip lines); and lower face (masseter hypertrophy, mentalis, platysmal bands and gummy smile). Each patient should be assessed individually to determine individual anatomy, including the size, strength and location of muscles, with doses being adjusted accordingly.