The cosmetic use of botulinum toxin.

The approach to facial rejuvenation continues to evolve. For decades, the primary focus on rejuvenation has centered on modalities such as skin care, skin resurfacing, soft-tissue augmentation, and surgical intervention. A better understanding of the physiologic changes that occur with facial aging lends itself to new approaches and techniques that are mindful of the causes. As animation has shown to be a significant contributor to both the appearance of facial lines and soft-tissue malposition, there has been recent interest in chemodenervating agents and their applications in the field of facial rejuvenation. These agents, by and large, efface rhytides by selective and precise focal paralysis of the underlying facial musculature and, therefore, reduce or eliminate the prominence of the overlying rhytides. In addition, chemodenervation can serve as an adjunct for facial rejuvenation because of its influence on facial soft-tissue position and shape. Botulinum toxin, derived from Clostridium botulinum, is the most widely used agent; therefore, this new modality, its applications in cosmetic plastic surgery, and its applications to other areas will be discussed.