Botox for Depressor Labii Inferioris to Control Chin Movement?

This off-label use of Botox should be done by an experienced Botox injector physician. A very low number of units should be injected, about one or two the most, per insertion, until the desired result is obtained. The physician should examine you by visualization as well as by palpating the chin and feeling the muscle movement as you smile to determine the origin of the involved muscle This will help determine the best placement for the Botox. Keep in mind that there could be an unwanted result such as lowering of the lower lip, drooling, difficulties with speech and playing a wind instrument. Should an undesired side effect occur, it could last three to four months before it resolves spontaneously.

Dear Schmoopy
Sure BOTOX is used to control the depressor anguli oris muscle. However, a far better approach is to fill these regions instead with hyaluronic acid fillers. Generally, the appreance of much this over activity is due to a loss volume. FIllers allow this to be addressed without a risk to the shape or function of the mouth.

This may fall into the category of trial and error. This sounds like an erudite discussion. However, until you try it, you never will know.
The difficulty is achieving the degree of precision with the injections that this demands and the obvious inherent inaccuracy of the procedure. Placing Botox can be similar to making an ink blot. It will turn out slightly differently each time it is injected. Botox diffuses and this cannot be controlled. It can be limited by concentrating the Botox to 1 unit per ml.

Simple answer = YES! But hard to achieve. You need to use a VERY experienced injector, taking they time and maybe multiple weekly visits to get the desired result. 
Best of Luck!

Hi!
A few units of Botox can stop the chin movements that bother you.  It's important to inject in just the right place, and to keep the dose small.

You have obviously done much research and consideration about the issue you perceive and the anatomy of the area. Most muscles are paired as agonists and antagonists ie. muscles that work in equal and opposite directions. Blocking one will accentuate the function of the other.
I can't say for sure if the treatment you propose will work but I would suggest you give it a try. Go to a plastic surgeon who will understand the anatomy you are discussing, not a non-physician injector. The worst that can happen is that it won't be effective. Either way, it will be gone in 4 months.