How is a midface lift (cheek lift) performed, is everything lifted off the bone completely?

I was wondering if the midface (cheek lift) is performed by lifting all of the tissue completely off the bone and elevating it to a new position? Would that decrease the blood supply to the bone? And also since it’s moving the cheeks up, will it change one’s smile? Also, does this surgery have the potential to put pressure on the lower eyelid area with time? Thank you!