This patient presented to my office with pain on his lower left wisdom tooth.  The image below shows the upper and lower LEFT side of the jaw.  On each arch you can see the bicuspid, 6 year molar, 12 year molar, and wisdom tooth. (Sometimes referred to as the 18year old molar)  Can u see where the pain is coming from?

I checked the wisdom tooth to be certain is was not causing pain.  Actually wisdom teeth themselves are usually NOT the cause of pain but rather the area around the wisdom tooth.  When a wisdom tooth has no room to erupt the patient gets swollen red gums and that is the source of pain.  The most reliable way to treat this is to remove the tooth so that the gums can close over and heal.

Back to the xray, there is a deep cavity on the lower 6 year molar (this is tooth 36, more about tooth numbers).  I tested his tooth by tapping (pain), and applying cold (intense pain with lingering).  This tooth needs a root canal.