Botox is approved by the FDA for treating wrinkles on the upper third of the face. Muscle contractions that form these expressions also create wrinkles in this area of the face. Wrinkles caused by facial expressions are known as dynamic wrinkles and they are the type most effectively treated by Botox injections. Injections of Botox are commonly performed on three main areas, including forehead lines, crow's feet lines around the eyes, and vertical frown lines between the eyebrows.