Dimple gone after upper teeth extraction. is this normal?

Not really: Not normal. Swelling might be affecting it. Another possibility is a change in the height of your teeth ie. The distance from your chin to your nose. It is what we call the vertical height.

Dimple: Your teeth provide support for the soft tissues for your face. If you loose back teeth your cheeks will automatically dip in where the teeth are gone. Also, as you decrease the number of back teeth your facial muscles become more lax and tend to droop. A dimple is created by toned muscles with the proper "support" by bones and teeth.

IDK: Most cheek dimples are the result of a shortened zygomaticus major muscle of the face which pulls hard enough on your cheeks to cause visible indentations on your face. The loss of the dimple might be due to swelling, stretching of the muscle or a mere coincidence as some people lose their dimples with age. Wait it out and see if it returns.

Temporary: Temporary. Swelling. Should return shortly.