>> reporter: unlike patients before him, oscar needed an entirely new face, skin, underlying muscles, teeth, lips, a new jaw. it is a long, tedious process. first, graph skin from the face of a donor. doctors careful to preserve arteries, veins and nerves. then using a powerful microscope doctors marry tiny veins and arteries from the donor to the recipient. they have to be similar diameters, they have to nearly match. then they wait. >> you have to hold your breath because you have to wait and see if it clots. if you see the tissue, it looks very pale. there's no blood flow in it. all of a sudden it flushes with red. >> reporter: in the end result, well, it resembles science fiction. one human face transposed on to another. >> people see that movie "face-off" and they think, we're going to look exactly like the donor but that's absolutely not true. it ends up being a composite. it doesn't look like the donor,