NIH grants fund TMJ research

A&M Baylor College of Dentistry’s Department of Biomedical Sciences has landed a $1.5 million National Institute of Dental and Craniofacial Research R01 grant for its study on estrogen and temporomandibular joint pain.

Co-principal investigator Dr. Larry Bellinger, Regents Professor and associate dean of research and graduate studies, refers to the funding as a “continuation” – an apt description, considering “Estrogen and TMJ Pain” builds on nearly 10 years of research and three previous NIH/NIDCR grants.

Dr. Phillip Kramer, associate professor in biomedical sciences, is principal investigator for the project, which already has warranted printing in several professional publications including the European Journal of Pain, Neuroscience and Endocrinology, among others. Dr. Rena D’Souza, professor in biomedical sciences, is also a collaborator on the study.

The latest research continues to evaluate how estrogen modulates orofacial pain but differs from the previous grants in one distinct way: It narrows the focus to myofascial pain. The current model tests pain in the masseter muscle, used for chewing. In the past, the department’s studies on estrogen dealt mainly with inflammatory orofacial pain, particularly TMJ pain.

“The reason we did that is because it appears that more of the TMJ disorders (TMD) are the result of myofascial pain instead of isolated inflammatory TMJ pain,” says Kramer. “Only 10 percent are inflammatory.”

The cause of the muscle pain is anyone’s guess.

“Something is going wrong in the muscle receptors of the people who have very bad TMD,” says Bellinger, who adds that the origin of that malfunction hasn’t been pinpointed to one root cause. He lists athletic and car accidents, talking on the phone, clenching the jaw during sleep and even chewing hard candy as some things that can set off the pain.

Through previous studies, Kramer and Bellinger have identified candidate genes believed to affect pain. With assistance from several collaborators at other institutions, the goal now is to regulate those genes to see how they impact myofascial and TMJ pain. The translation from basic research to clinical care could take years if not decades, say the researchers.