One of the most common first signs of aging manifests itself in wrinkles in the forehead area of the face. Repeated facial expressions and movements — squinting, smiling, furrowing your brow — can lead to fine lines and wrinkles. When facial muscles are used, a groove forms beneath the surface of the skin, and that groove may no longer be able to spring back in place as skin ages and loses its elasticity. As a result, the repeated creasing and lines can become permanent over time.