I periodically get a very sharp pain up the side of my face usually brought on when i am eating (its not my jaw) what could this be? tmj?

Certainly could be: The side of your face has several muscles that could be the source of your pain or it could be the TMJ itself which is right in front of your ear canal. Try Ibuprofen and tylenol (acetaminophen) if it isn't severe pain as often these issues are transient. If the pain doesn't respond well and disappear completely in a few days, get to a dentist for an evaluation.

An be tooth: It may be a tooth. I think you need a thorough comprehensive evaluation by a dentist.

Could be TMJ: It might be tmj, or could be a problem with a tooth as well. A "cracked" tooth can cause pain when chewing- a sharp pain that could radiate to the side of the face. A worn or faulty tooth restoration could also be the problem. You need to have a dental examination to diagnose and treat the problem. Tmj can cause other symptoms as well- headaches, difficulty opening, clicking in jaw.

Probably muscle: Pain is very often coming from the muscles that move the jaw, especially if the muscle is activated as in chewing. Put your finger over the area that is painful and see if when you bite down it is in the muscle. If it is you will need to find someone that can help you get the system back into a better functional position and posture.

Yes: Yes, could be. See a TMJ expert to evaluate. Any dentist can be a TMJ expert with the proper training and experience. Most commonly, oral surgeons, prosthodontists, and orofacial pain specialists. Ask your MD, your dentist and your dental society for referrals.