Exercise relieves jaw pain – but the effect isn’t the same for everyone
One in ten Swedes lives with chronic pain in the jaw, face or mouth. A new doctoral thesis now provides in-depth insight into how this pain affects those affected and why pain-relieving jaw exercises have varying effects on different people.
This type of pain, known as orofacial pain, can make it difficult to chew, speak and eat. For many, it affects both their well-being and quality of life in the form of constant ache and fatigue in the jaw muscles. The condition is particularly common among women and young adults.
Although jaw training is the most common form of treatment for restoring function and relieving pain, we have so far had surprisingly little knowledge of how the brain and nervous system react to this training.
Nikola Stanisic
The most common cause of these problems is temporomandibular dysfunction (TMD) – a collective term for pain and disorders in the jaw joints and jaw muscles. Often, it involves clenching or grinding the teeth or tensing the jaws without being aware of it.
“As many people do this without realising it, these behaviours can be difficult for a dentist to detect and assess,” says Nikola Stanisic, a PhD student at the Faculty of Odontology, Malmö University.
Exercise is a common form of treatment; the aim is to improve function, reduce pain and strengthen the jaw system’s ability to cope with stress. Stanisic’s thesis now shows that the effect of this exercise varies depending on the individual’s pain level and the strain placed on the jaws in everyday life.
He has arrived at these findings by investigating, on the one hand, how pain and overuse affect jaw function and jaw muscle activity, and, on the other hand, how the masticatory system responds to exercise and how the brain and nervous system adapt to this exercise – a process known as neuroplasticity.
In addition, he has conducted a systematic review of previous relevant research on pain and neuroplasticity which, however, has rarely focused on the masticatory system.
“Although jaw training is the most common form of treatment for restoring function and relieving pain, we have so far had surprisingly little knowledge of how the brain and nervous system react to this training,” says Stanisic.
In the studies, participants underwent a short jaw training programme. It was found that training improved jaw function in both pain-free individuals and those with pain – but that pain and strain affected the degree of improvement. The brain’s motor system was altered by training, but adaptation was slower in people who frequently clench their teeth or tense their jaws, a condition known as bruxism.
The study showed that there is a clear link between how people themselves perceive their jaw tension and the actual muscle activity. People experiencing pain had longer periods of low-intensity muscle activity. This likely reduces the muscles’ ability to recover.
“I hope the results will contribute to a better understanding of TMD pain and that clinicians will look not only at the pain, but also at how patients use their jaws in everyday life. With this knowledge, we can design more accurate and personalised treatment for jaw pain,” adds Stanisic.
