The way the neck ages depends on several factors, such as genetics, damage to actin filaments and alterations in weight. As individuals age, the chronic effect of the platysma pulling downwards is the formation of vertically oriented bands of fibrous tissue. Meanwhile, horizontally oriented wrinkles form due to the skin overlying the platysma and becoming laxer over time. The most oversized fat pad under the chin herniates between the platysma’s free margins due to the platysma and SMAS pulling downwards, coupled with degeneration of the skin and muscle that occurs with aging. Medical interest in Clostridium botulinum dates back to 1897, when it was discovered that this Gram-positive bacillus synthesized a toxin causing botulism. There are now seven forms of the botulinum toxin, produced by different bacterial strains, which can be distinguished serologically. These serotypes are as follows: A, B, C1, D, E, F, and G. These serotypes have differences in their pharmacology. Toxins A and B are generally used in clinical applications, but in cosmetic use, toxin A predominates. The first clinical application of botulinum toxin was to remedy strabismus. Since then, it has been used to treat a number of other disorders in which muscles contract excessively, such as blepharospasm, hemifacial spasm, and spasmodic torticollis.