The typical profile of patients with TM Disorders is of women in their child-bearing years. This means that they undergo fluctuating levels of estrogen in the bloodstream, depending upon the phase of the menstrual cycle, with estrogen levels highest near ovulation.
Researchers studying an experimental TMJ pain model in rats have noted that pain in these female animals appears to be reduced in the pre-ovulatory phase when estrogen levels are highest.
Now, a team of scientists, headed by Dr. Philip Kramer at Texas A&M Health Science Center, Baylor College of Dentistry, have screened animals' nerve tissue that supplies sensation to the TM joint area to see whether there are specific genes which are turned on in response to stimulation by estrogen. (There are estrogen receptors in the nerve tissue of interest.) Their article cites two genes in particular which code for proteins that can reduce pain signals from the joint area and which are more active (gene expression is increased) in response to estrogen. In continuing studies the researchers are manipulating expression of these genes to see how changes in gene activity affect the animals’ pain behavior and whether this is, in fact, the mechanism by which estrogen affects responses to pain.
©2011 The TMJ Association, Ltd. All rights