All-over pains predict jaw disorders

U. BUFFALO (US) — People who develop jaw problems known as TMD exhibit specific traits, including more trauma to the jaw, more limitations and noises in the jaw, more headaches, and generally worse medical status.

The findings are expected to help researchers and clinicians better understand temporomandibular disorders (TMD) and other pain conditions&mash;and more effectively manage and treat the conditions.

Published in the November issue of the Journal of Pain, the results are part of the Orofacial Pain Prospective Evaluation and Risk Assessment (OPPERA) study, which followed 3,200 initially pain-free individuals for three to five years and is the largest clinical study of pain conditions that has ever been done.


“The UB role in the project was to develop well-designed examination procedures to help dentists and other health care providers identify risk factors for TMD,” says Richard Ohrbach, associate professor of oral diagnostic sciences at the University at Buffalo and lead author of the paper.

Ohrbach and colleagues studied 71 different clinical variables in 1,633 controls—individuals who never had TMD—and in 185 people with chronic painful TMD.

Individuals were assessed using lengthy questionnaires about health histories and current symptoms and through clinical exams. Participants were from western New York, Maryland, North Carolina, and Florida. The researchers found a very high rate of the variables they assessed, 59 out of 71, were significantly associated with painful TMD.

“Our results indicate that individuals with TMD differ substantially from the controls across almost all of the variables we assessed,” says Ohrbach.

TMD sufferers tended to have significantly higher levels of the following variables: trauma to the jaw, non-pain symptoms in the facial area, jaw locking and noises, and pain during such jaw movements as chewing, smiling, or talking. While the last two findings were clearly expected, very little has been known about the first two findings.

In particular, TMD sufferers reported a much higher rate of neural and sensory medical conditions, such as earaches, tinnitus or hearing loss, fainting and dizziness, and seizures due to epilepsy and other conditions.

The study also confirmed many findings that long have been associated with TMD but which have not, until now, been proven in a comprehensive, large-scale study, including that any pain disorder, such as headache, backache and abdominal pain, is more likely to occur in TMD patients than in people who do not have TMD.

“Why are other pain disorders more common in people with TMD?” asks Ohrbach. “Is it because those pain conditions predispose them to develop TMD or do they develop TMD first and does TMD lead them to then develop other pain disorders?”

To answer these and other related questions, Ohrbach says the next step will be to look at comorbidity. “We’ll be tracking these multiple pain disorders over time with particular variables,” he says.

Ultimately, the findings will be geared toward a better understanding of pain conditions in general.

“How do we understand the pain? How do we establish a reliable and clinically useful marker of pain so that significant pain can be more readily diagnosed?” asks Ohrbach.

“To answer these questions, we need to have a model that puts all of the pieces together, that takes the findings from a clinical exam, puts it into a rigorous framework using the right assessment and diagnosis tools in order to chart the nature of multiple physical disorders so that we can ultimately understand how the pain is affecting the individual.”

The OPPERA study was funded by the National Institute of Dental and Craniofacial Research. Co-authors include scientists from the University of Florida, the University of North Carolina-Chapel Hill, the University of Maryland-Baltimore, and Louisiana State University.

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