Abstract

Botulinum toxin A (BoNT/A) is a zinc-dependentendopeptidase composed of a heavy and a light chainconnected by a disulfide bond. The toxifying light chaininteracts within peripheral nerve endings with asynaptosome-associated protein, SNAP-25, that specificallyinhibits the transport of acetylcholine to the cell membrane.BoNT/A temporarily chemically denervates the muscle. Incase of hyperactive facial muscles this leads to asmoothing of the facial appearance with a natural friendlyand relaxed expression. The detailed knowledge of theactive compound and the anatomy are prerequisites ofBoNT/A usage in cosmetic medicine. There are classicalindications of BoNT/Afor horizontal lines of the forehead,frown lines and Crow’s feet. The technique and dosages willbe explained in detail. Other indications include bunnylines, brow lift, suborbital usage to open the eyes, upper liplines, gingival smile, marionette lines, cobblestone chin andmental crease. There is a large scientific background for thecosmetic use of BoNT/Aavailable since large multicentrecontrolled trials have been performed and are continued.Evidence-based medicine shows that BoNT/Ais a safe andeffective treatment of hyperkinetic wrinkles. It also can beused as an adjunct to laser, medical peels, fillers, andcosmetic surgery. Recent investigations suggest a positivelong-term effect on dermal and epidermal remodellingand therefore anti-ageing activity.