Because when your body is under anesthetic your body’s reflexes are temporarily stopped so if there is food or liquids in your stomach there is a chance you might throw up
It’s due to the blood, and many more. First the blood is not stopping, so they put the little tissue sized things in your mouth that you need to bite down on. Also, they might’ve put some sort of medication on your tooth after removed, to help it being relieved, so you need that to stay on there.
