Most of the time when a frown line is etched-in or static, it needs to be treated with Botox and a filler. Since a filler lasts longer, though, many people wonder why you need both.
Here’s why. Frown lines between the eyebrows develop primarily because of repeated movement of the muscles in that area which wrinkle the overlying skin. When the wrinkles are not etched-in, Botox limits the movement of the underlying muscles and reduces the amount of wrinkling. When the line is etched-in, you need a filler such as Juvederm, Restylane, or Belotero to fill the crease.
You still need Botox, though, because the line developed in the first place because of muscle movement and wrinkling is the root cause of the problem. If you only fill the line without treating the underlying root cause of the wrinkle, the filler will break down more quickly and the line with reappear.
If you use both a filler and Botox, the results will last longer and you may find that you won’t need filler as time goes forward as your skin adapts to it’s new, non-furrowed state.