How does Ultherapy work to correct botched fat grafts? (Photos)

I had fat grafts to my cheeks and sides of my face around my mouth in 2012. They were overfilled and have continued to grow and are very lumpy. I can’t even smile the same now because of the volume of the cheeks and sides of my mouth. Some lumps are hard. I’ve seen some PS’s recommending Ultherapy to improve this. How does this work and what do I tell the person performing the procedure to achieve the best results not only to reduce the volume but smooth the vast amount of irregularities.