Botulinum neurotoxin (BoNT) injections are the most commonly performed cosmetic procedure in the USA. Rhytids, commonly known as wrinkles, develop over time from repeated pleating and contraction of underlying skeletal muscle along with decreased elasticity and thickness of the overlying skin. Typically, rhytids appear perpendicular to the direction of muscular contraction.

BoNT prevents skeletal muscle contraction by inhibiting acetylcholine release from the neuromuscular junction, thereby relaxing the relevant muscles. BoNT can soften the appearance of rhytids and reduce further formation. This chapter discusses the use of BoNT specifically for the treatment of rhytids of the upper face including the glabella, forehead, peri-ocular region and nose. Many of these treatments are considered off-label but are known to be safe and effective.

In 1980, Alan B Scott published the use of botulinum neurotoxin type A by injection into extraocular muscles for treatment of strabismus. Use in blepharospasm was published in 1985, and cervical dystonia in 1986, followed by hemifacial spasm and other dystonias, including spasmodic dysphonia, hand dystonia, and conditions such as limb spasticity.

Formulations of neurotoxin type A worldwide include: Botox/onabotulinumtoxinA, Dysport/abobotulinumtoxinA, Xeomin/incobotulinumtoxinA, and a Chinese product marketed under various brand names in Asia. Botulinum neurotoxin type B is marketed as Neurobloc/Myobloc, or rimabotulinumtoxinB. PrabotulinumtoxinA and daxibotuinumtoxinA-Ianm are type A toxins under development.