My 30 Year Old Son Is Complaining Of Left Sided

My 30 year old son is complaining of left sided jaw pain. No swelling/redness on gums, no external swelling. Just pain with eating. He states he feel asleep at his desk with his head on his shoulder and now he has pain. I asked if he had cut himself this week and he showed me an abrasion on his left shin from walking into a shelving unit at work. No swelling in that area and minimal redness.