Clicking without pain is normal. It sounds like you may be grinding your teeth which has caused your masseter to hypertrophy. It's the muscle that closes your jaw. Some signs of grinding is pain or "tightness" in your teeth in the morning. Have you had increased stress in your life. As stated As can cause anxiety which could cause you to do this. A Dentist can make you a night uard to wear which will help if this is the case. Are you taking GH?