24 & some jowls, is Ultherapy a solution to define round face? (Photos)

I have a round face with some jowls (even thoughy im 24) and after some googling i came upon ultherapy. i have a rather weak jawline and some looseness, and this seems like a perfect solution for a more defined jawline. but some people online mention that the procedure melted their fat. now a little bit of fat melting i wouldnt mind as ive also considered buccal fat removal but i dont want to end up with way saggier skin. What should i expect? And is there a difference between hifo/ultherapy?