Both are temporary injectable treatments. Facial muscle relaxant injections are used to relax the muscles that underlie the lines which become more visible through movement and age. Dermal fillers are used to lift out wrinkles that stay when the underlying muscles are relaxing and to restore skin volume and add contour to the aging face.
A general rule of thumb is anti line and wrinkle injections are used for the upper face and dermal fillers are used on the lower face.