Can Botox/Dysport under or in the chin cause more sagging under the chin?
Generally not ………and here’s why. If she put the Botox IN the chin muscle itself (mentalis muscle), and if it’s placed properly, it should relax those little “orange peel” dimples that many people get in the chin as we age. If it’s not placed properly IN the chin muscle, it can pull your smile off temporarily.
If it was placed UNDER the chin, then chances are she was trying to place it in the large bands (platysmal bands) that wrap from the neck up over the jawbone. Relaxing the platysmal bands a little will often make those bands go back up under the jaw where you want them instead of sticking out.
If she placed the Botox just in the skin, nothing will happen either good or bad because Botox isn’t active in skin …..only muscle. The same thing applies for fat under the chin. If the Botox/Dysport is placed there, nothing will happen because the only receptors for it are in muscle.
Hope this helps, Dr. I