What can cause jaw clicks when i open my mouth?

Jaw clicks: Jaw clicks are usually caused by excessive muscle activity or tension in the muscles that control the jaw (primarily the masseter muscle). This problem correlates mostly with either chronic severe stress (in which case you have to destress yourself) or bad chewing habits (like chewing on pencils). Occasionally a problem in the bone, usually arthritis, may also cause this symptom.

TMJ: Disk out of position. If no other symptoms, no treatment necesssary. If locking or limited movement, "ear" pain, headaches, morning stiffness/soreness, difficulty chewing, bruxism, previous jaw injuries other other jaw conditions, more serious problem. See TMJ expert.