One person gets migraine headaches, another ringing in the ears, a third clicking and locking of the jaw, a fourth pain on the sides and back of the head and neck. All are suspected of having a temporomandibular disorder.

Up to three-fourths of Americans have one or more signs of a temporomandibular problem, most of which come and go and finally disappear on their own. Specialists from Boston estimate that only 5 percent to 10 percent of people with symptoms need treatment.

Popularly called TMJ, for the joint where the upper and lower jaws meet, temporomandibular disorders actually represent a wider class of head pain problems that can involve this pesky joint, the muscles involved in chewing, and related head and neck muscles and bones.

But too often, experts say, patients fail to have the problem examined in a comprehensive way and undergo costly and sometimes irreversible therapies that may do little or nothing to relieve their symptoms. As scientists at the National Institute of Dental and Craniofacial Research wrote recently, “Less is often best in treating TMJ disorders.”