[PeterisP]

It's not about cosmetics that can be tackled with a high quality mask - it's also about all the practical functions that the face needs to tackle; e.g. the lip musculature necessary for speech and eating, eyelid/tearduct function, and nose breathing. If you're missing lots of tissue from your face, you will need a transplant (inevitably high maintenance) of some kind, so it might as well be a full-face one.