The National Institute of Dental and Craniofacial Research (NIDCR), part of the National Institutes of Health, intiated a seven-year clinical study that could accelerate research on better pain-controlling treatments for a jaw condition called temporomandibular joint and muscle disorders (TMJDs).

Orofacial Pain: Prospective Evaluation and Risk Assessment or OPPERA, the $19.1 million project marks the first-ever large, prospective clinical study to identify risk factors that contribute to someone developing a TMJ disorder. A prospective study looks forward in time, tracking volunteers over several months or years to monitor the onset and natural course of a disease, states a NIH release.

During the OPPERA study, scientists will track 3,200 healthy volunteers from three to five years to see how many develop the disorder. According to Dr. William Maixner, the study's principal investigator and a scientist at the University of North Carolina in Chapel Hill, those who develop TMJ problems will open a critical and largely unexplored window on the early stages of the disorders, pointing the researchers toward genes and other biologic factors that might contribute to pain sensitivity.

Maixner said, “The high-quality data generated from this prospective vantage point could provide the future impetus to refine diagnostic criteria for TMJ disorders, consider new approaches to treatment, and predict a person's natural susceptibility to develop a chronic pain condition.”

"This is a timely study that will greatly enhance the scientific underpinnings of research on TMJDs. Most importantly, it will accelerate the pace of the science and seed valuable new leads that impact virtually every aspect of care for the disorders,” said NIDCR director Dr. Lawrence Tabak.

According to NIH director Dr. Elias Zerhouni, this study represents an important step forward not only for TMJD research but pain research in general. It marks one of the first prospective clinical studies to identify risk factors for a chronic pain condition. It's quite possible that some of the findings that arise from this study will be applicable to other musculoskeletal pain conditions.

TMJD is an umbrella term for a group of conditions that affect the area in and around the temporomandibular joint, or TMJ.

Although TMJ disorders vary in their duration and severity, for some people the pain becomes a permanent feature of their lives, and controlling it can be an exercise in frustration for them and their doctors.

One reason that relief is so difficult to find is the chronic pain associated with TMJ disorders results form a highly complex biological interplay. The interplay involves myriad factors, ranging from the intricacies of pain transmission and its possible rewiring and over amplification en route to the brain to the complicating and frequent presence of other painful conditions, such as fibromyalgia and chronic fatigue, which possibly mask or modify the symptoms of the TMJ problem, informs the release.

With so many variables, some researchers have suggested that the best scientific entry point to examine a TMJ disorder is during its earliest stages, before the full-blown complexity of advanced disease clouds the investigative picture. This thinking and recent progress in studying the basic biology of pain led to the NIDCR's decision to support the OPPERA study.

This study builds on the recent completion of a successful three-year, prospective pilot study in North Carolina that involved 240 healthy women who initially had no history of a TMJ disorder. In the OPPERA study, participants may be both male and female. All must be between the ages of 14 and 44, in good health, and have had no previous TMJ problems. Based on the results of the pilot study, Maixner said that an estimated 200 volunteers may develop their first TMJ disorder during their participation in OPPERA.

"A large prospective study on a TMJ disorder would have been futile just a decade ago because not enough was known about the basic mechanisms that control human pain. It's only been within the last few years that an adequate conceptual framework has emerged, and I'm very hopeful OPPERA will identify key genetic, physiologic, and psychological variables that tell us more about patients and, ultimately, lead to more effective treatment approaches," said Maixner.

The National Institute of Dental and Craniofacial Research is the leading institute of research on oral, dental, and craniofacial health.