Facial lines caused by muscle movements, such as squinting or smiling, are known as dynamic wrinkles. This type of wrinkle can be tough to prevent and treat and may make you look sad or angry even when you are in a good mood. Tiny muscles cause the skin to fold when you make a facial expression, and over time, these folds become deeper and more permanent. BOTOX® Cosmetic can be used to soften facial lines and creases to provide a more youthful and refreshed aesthetic.