Temporomandibular disorder (TMD)-related pain is believed to occur more commonly in women than men. However, strategies that target women's hormonal cycles to control pain appear to be ineffective, according to a new study (Pain, June 14, 2011).
Previous studies, including work by the University of Washington research team that authored the new study, have shown TMD pain to fluctuate in accordance with the menstrual cycle, including a secondary pain peak around the time of ovulation.
Some have theorized that estradiol can play a key role by modulating facial pain and contributing to an increase in TMD-related headaches during menstruation.
To determine if therapies that target hormonal cycles can therefore help alleviate pain, the researchers compared three treatment strategies applied to women with TMD-related pain.
For the randomized study, one group of 59 women received general self-management pain training delivered by dental hygienists. A second group of 55 women also received hygienist-delivered pain management training, but the therapy was targeted specifically to menstrual cycle-related shifts in pain and other symptoms. A third group of 57 women received continuous oral contraceptive therapy aimed at stabilizing the hormonal-related changes believed to be related to TMD pain.
According to participants' reports on various measures of pain and coping before the interventions and at six and 12 months following treatment, those in each of the two behavioral therapy groups did have significant improvements in pain management compared with those in the contraception group.
However, the self-management approach that targeted women's menstrual cycles was no more effective than the general approach that did not focus on the cycles, the researchers noted.
"We had predicted that anticipating critical times in the menstrual cycle when women were at risk for increases in TMD pain would be helpful, so that women could make plans to use pain self-management skills during those times," lead author Judith Turner, PhD, of the University of Washington Department of Psychiatry and Behavioral Science, said in an interview with DrBicuspid.com. "We were surprised that the self-management therapy targeted to menstrual cycle changes was no more effective than the standard self-management therapy."
The self-managed therapy included two in-person sessions of 1.5 hours each at the University of Washington Orofacial Pain Clinic and six 10- to 15-minute telephone contacts with dental hygienists who were trained and supervised by a clinical psychologist.
The sessions provided standard cognitive-behavioral pain therapies and interventions for chronic TMD pain. Patients were also provided with educational materials about TMD pain, relaxation and stress management training, discussion of the role of emotions and stress in exacerbating pain, instructions on self-monitoring of symptoms, and preventing relapse. Activities such as jaw posture monitoring, relaxation, and breathing were also recommended as part of the intervention.
Patients in the group with self-management treatment targeted to menstrual fluctuations were also informed of the potential effects of hormones in TMD pain and instructed to plan for possible increases in pain related to the hormonal fluctuations.
Women in the contraception group did not receive self-management therapy.
The results showed no significant differences among the three groups at the six-month assessment. However, the two self-managed groups reported significantly lower pain intensity than the contraception group at 12 months (p < 0.05), and a similar pattern was seen for activity interference and sensory and affective pain scores.
Despite the negative findings in relation to hormonal fluctuations, the results underscore a potential significant benefit in cognitive-behavioral therapy for female patients with TMD-related pain, Turner noted.
"Dental professionals who see patients with TMD pain might consider referring their patients for pain self-management skills training or cognitive-behavioral therapy, if resources for this are available in their community," she said. "If these resources are not available, dental professionals might recommend pain self-management books to their patients, as well as CDs or MP3 files of progressive muscle relaxation, and encourage their patients to practice muscle relaxation on a regular basis."
Other treatment options
While the improvement seen with behavioral therapy appears promising, the approach addresses TMD pain as a chronic condition, which is just what first-line treatment should aim to avoid, according to Matthew Messina, DDS, a spokesperson for the ADA and a dentist based in Fairview Park, OH.
"TMD is a treatable condition, and as such the current study in question seems to me to be an answer to the exceptionally small number of cases that are so intractable as to require chronic pain management," he said. "I would much rather treat the cause of the pain than work with the patient to manage their pain, as long as treatment options exist."
Patients who are referred to cognitive-behavioral therapy too soon may get a mistaken impression about the true cause of their pain, he added.
"One of the first tasks that I have is often to convince the patient that they can get better and that there is a reason for their pain," Dr. Messina said. "Referral to psychiatry for behavioral therapy would reinforce the feeling that the patient needs psychiatric help."
The research is nevertheless valuable in contributing to efforts to gain a better understanding of exactly which treatment approaches can be effective, he added.
"Each study can be an important piece of the puzzle, but we have to look at its implications to the whole and not as the answer," he said. "Treatment of TMD requires having a number of treatment options in our toolbox because each case is individual, and we may use a variety of treatment modalities for each person. The good news is that treatment is effective, and it is getting better with each passing year."