The buccal fat pad is a deep compartment of fat that sits between the cheek muscles, separate from the fat just under the skin. It has several extensions, and the one that matters here is the part that bulges forward into the lower cheek. Buccal fat removal, sometimes searched as buccal pad fat removal or cheek fat removal, takes out a controlled portion of that part, not the whole pad.
The effect is a slight softening of fullness below the cheekbone, seen most clearly in three-quarter view. The cheekbones can look more defined by contrast, but the bone itself does not change. Because the fat sits deep and only a portion is removed, facial expression and movement are normally preserved.
What it does not do matters just as much. It does not reduce overall facial fat, lift jowls or loose skin, shrink a bulky jaw muscle, or treat fullness under the chin, which is the job of double chin liposuction. A round face usually has more than one cause, and the examination separates them before any plan is made.