Where exactly is the masseter muscle inside the cheek? If I run my finger to the inside of the mouth top of inside cheek by the top of the gum" I find a very very sore spot is this the muscle and how would you suggest massaging this muscle, I have the teeth clenching, eye twitching, have had a wet eye for months I am thinking this muscle may be the cause of these problems. Any help is greatly appreciated. Thank you. The other side of the mouth has no pain.