Stress, Estrogen Connect Co-Occurrence of Irritable Bowel Syndrome, Temporomandibular Disorders

As more than 60 percent of women with temporomandibular disorders (TMD) also exhibit abdominal pain consistent with irritable bowel syndrome (IBS) symptoms, two researchers in the neural and pain sciences department of the University of Maryland School of Dentistry, in Baltimore, have developed an animal model to better illustrate the two conditions’ comorbidity.

Backed by a $275,000 grant from the National Institutes of Health (NIH), Richard Traub, PhD, and Dean Dessem, PhD, studied the correlation between IBS and TMD and discovered that subjects with jaw pain — a common symptom of TMD — who were subjected to subchronic stress experienced pain in their lower abdomens, though that pain only intensified when estrogen was present.

In an abstract presented to NIH, the scientists said their study “addresses the hypothesis that masseter muscle inflammation plus stress induces colonic hypersensitivity that is modulated by gonadal hormones (and that) the visceral hypersensitivity results from central sensitization at the level of the spinal cord.”

According to Dessin, the estrogen-dependent relationship between TMD and IBS showcased in the new model may have implications beyond those conditions, since fibromyalgia and other chronic pain syndromes also display certain simultaneous occurrences, he said.

Dessin said in a news release those potential implications lend significance to the results because “it is likely that comorbidity between all these different conditions has some commonality,” and he noted “our goal is to develop a better understanding of the mechanisms that exist between these relationships.”

Traub added uncovering new remedies for chronic pain syndromes “is a very relevant issue (since) pain is the number one reason people go to the doctor. It’s the number one reason people miss work.”

“Many functional chronic pain disorders occur in clusters of two or more conditions. Our long-term goal is to determine the mechanisms underlying the development of pain from healthy tissue using this model,” the researchers wrote in their grant application. “This will provide targets for better pain management.”