Can RF or similar be used for a nonsurgical lip lift?

If you are only trying to lift the center or corners of the mouth or increase tooth show by a few millimeters, can Radio Frequency or some sort of skin tightening technology accomplish this? I have seen procedures such as Thermitight lift the skin by centimeters, so why is it never used to lift lips? (at least I haven't found anything from searching online). Thank you!