I have hollow cheeks, how much filler would be required? (Photo)

Last summer, I had upper jaw surgery to correct an under bite. Since then, you can really tell how hollow my cheeks are. I recently got 1 ml in each cheek of Juvederm, but it barely made a difference. I'm going back in a couple of days, how many mls would be required for natural but noticeable cheeks? (First photo left side is with no fillers at all)