RA can affect your jaw, but if it's ONLY your jaw, I wouldn't jump to conclusions. In general, RA manifests with fever, overall body aches/fatigue, and swelling/redness/pain in more than one joint. Typically, to my knowledge, it rarely starts in the jaw. It'll be your knees, feet, or hands/wrists first. Jaw tightness and pain could simple be stress from worrying about the incident.