Dental filling procedure doesn't causes these things. If local anaesthesia
is given to you then its effect makes one feel that his one side of cheek gets swollen and his face becomes distorted. Its normal feeling after local anaesthesia injection. Becomes difficult to spit and talk for 2-3 hours. If your problem persists long or you have any other problem or it happened without any local anaesthesia injection then you should consult your Dr. further.