Several hours after Dysport in my forehead my cheeks started sagging. Did the Dysport migrate and affect cheek muscles?

Hello, and sorry to hear about the issue you experienced. In general, the side effects of Dysport may include the following:

1) Swelling
2) Light bruising
3) Eyelid ptosis
4) Redness around the injection site

What you are describing is not a typical result of Dysport. The Dysport will not migrate from the area where it was injected. An exam would really be necessary to provide you with the best advice. I would recommend following up with your provider and see what he/she recommends. Unfortunately, facial exercises will not likely help improve your issues. Thank you and good luck!

It's not likely the Dysport treatment is responsible for what you are experiencing.  Dysport would not exhibit significant activity in 2 hours, and it would be exceedingly unlikely for it to migrate from your forehead to your cheeks.  

After having Dysport injected into the forehead, it would be highly unusual for the Dypsort to migrate to the lower eyelids and cheeks.  Since it's been about 4 months since you had the treatment, the effect from the Dysport should be wearing off about now, although it could take another month or two.  I would recommend just keeping an eye on it for another month or so but if it is an issue for you, you should return to the physician who treated you to be evaluated.  

This sounds odd as you shouldn't see any affect for a few days. After only a few hours, the drug hasn't had time to really do much of anything.  Also, migration can occur to adjacent tissues, but to travel all the way to the cheeks would be very unusual.  Go back and relate this to your injector as I suspect there is some other explanation.

I have never had any issue even close to this with Dysport or Botox. These types of injections migrate very, very minorly. Not like what you are describing at all. I cannot see a forehead injection traveling down to the ocular area. The forehead is the only place you had these injections, and you are sure you had true Dysport from a legitimate injector? Dysport begins to wear off after 3 or 4 months, so if you don't start seeing some improvement soon, something else is occurring.