TUESDAY, Nov. 15 (HealthDay News) -- People with chronic jaw pain have increased pain sensitivity in other parts of the body, a new study says.

This and other findings from the study could lead to new ways of diagnosing facial pain conditions, predicting who is susceptible to them, and perhaps lead to new treatments, according to the investigators.

The study included 3,200 healthy volunteers ages 18 to 44 who were followed for three to five years to see how many developed temporomandibular joint disorders (TMJD), which produce pain that radiates from the jaw and surrounding muscles.

The researchers found that those who did develop TMJD had heightened sensitivity to mildly painful sensations in other parts of the body, were more aware of body sensations, and had more significant heart rate increases when they were under mild stress.

The study appears in the November issue of the Journal of Pain.

"There is a real difference. People with TMJD are more sensitive than those without TMJD on parts of the body other than the jaw," co-author Joel Greenspan, professor and chair of the department of neural and pain sciences at the University of Maryland School of Dentistry, said in a university news release.

"To us it means the nervous system for interpreting pain information is now altered. We think that general heightened pain sensitivity is part of the chronic pain problem," Greenspan explained.

He and his colleagues also identified several genes that may be involved in TMJD and could offer targets for new drug treatments. These genes include some known to affect stress response, inflammation and mental well-being.

More information

The American Dental Association has more about jaw pain.