Dr. Ivana Dabaj Pediatric Neurology
It could be a problem in one of the temporomandibular joints (the joints of your jaw). You should avoid chewing gum and hard food. If it persists you should see an ENT (ear-nose-throat physician).
Dr. Salim Saab Otolaryngology (ENT)
it is probably a stress problem affecting masseter and buccinator muscles need more relaxationof your muscles