Pouch, fat, or filler migration by mouth? (Photo)

Your filler is gone by now and this is excess skin from weight loss. I would suggest micro-needling with radiofrequency, like Secret, for skin tightening.

The contour issue is most likely similar to what causes Peri oral mounds. It’s definitely not buccal fat and it’s not migration of fillers, which in my opinion doesn’t actually happen. Facial contour is made up of many different components. The first and primary is facial bone structure. After that they’re on the regular soft tissue layers, and then finally contour related to tension and contraction of all the muscles of facial expression. Reducing the volume around your lip is going to be difficult so the easiest and most likely best treatment is to augment they are young, just adjacent to it.
We can sometimes so often Giles by adding fillers in front of the Joe call the pre-Jowl sulcus. In the same way fillers could be added just behind the area fullness as the transitions to your cheek.
It may not be easy or straightforward, and you should look for highly experienced senior providers who have a lot of experience.
I don’t think you’ll find any single diagnosis or abnormality.
Mats Hagstrom, MD