I had 4 2nd premolars extracted for braces when i was 27. i only had very minor crowding on top. now my cheek & temple had sunk in. can it be reverse?

Complicated Answer: You've undergone orthodontic treatment with 4 extractions... This was to create room for moving the anterior crowded teeth. The distalization of these teeth may have changed your lip position, but should not have affected your cheeks and certainly not your temples. Consult with your orthodontist and possibly a plastic surgeon.

Correcting sunken in: Consult an orthodontist who uses the damon system. There is claims that you can guide bone with tooth movement, therefore you can correct the cave in effect. Good luck!