TMJ, or temporo-mandibular joint disease, is a very common condition responsible for many cases of ear pain, jaw pain and headaches. There are many different explanations for why this happens, but the general explanation is that your muscles that close the jaw go into spasm, and due to extra pressure on your jaw joint, produces ear pain, which can radiate up or down the side of the head.
Various conditions can aggravate this condition, such as stress, teeth grinding or clenching, recent dental work (producing an uneven bite), or for sometimes for no obvious reason. The pain can be sharp and throbbing, or can produce a dull ache. Sometimes chewing makes it worse.
Treatment is usually conservative. In most cases, going on a soft diet, using warm compresses on the side of the head, and using NSAID medications such as ibuprophen or naproxen as an anti-inflammatory medications will help. If not better in 3-7 day, a dentist can fabricate a mouth guard to help relax the muscles at night.
As with any form of ear pain, a thorough exam is needed to rule out other causes, such as an ear infection, dental pain, sinusitis, or one of the headache syndromes.
In severe cases, Botox also has been used successfully in selective cases.