The horizontal wrinkles on your forehead are called the forehead wrinkles. By raising your eyebrows, they become clearly visible. Usually these are small superficial lines or slightly deeper wrinkles. As we age, the elasticity of the skin diminishes and these wrinkles show up more and more. The activity of the forehead muscle (musculus frontalis) is responsible for this. With Botox we give this muscle more relaxation so that the forehead lines fade.