Medically reviewed by Brittany Ferri, PhD
You may not have heard the word ‘bruxism’ before, but if you’ve ever woken up or finished a long day of work with a sore jaw, you’ll be all too familiar with it.
What is clenching?
Jaw clenching is one of the behaviors that falls under the umbrella term ‘bruxism’ – where your chewing muscles are contracted and teeth are pressed together. Bruxism can also involve teeth grinding, thrusting of the jaw (where your lower jaw is pushed forward), and bracing (tensing up jaw muscles without tooth contact). All of these movements tend to be repetitive or sustained for long periods of time, often while you’re unaware.
How do you know if you clench?
Most of us do experience some levels of bruxism during our lives, but it’s only when these clenching / grinding behaviors become severe that you can experience:
- Tension headaches or migraines
- Pain around the jaw, neck, and face
- More sensitive teeth
- Disrupted sleep
At its most severe and left untreated, there can be further complications for your teeth and muscles.
Why do we clench?
If it’s something most of us do, why do we do it? Well, there’s some evidence that we do it subconsciously to improve our cognitive and motor function. If you’ve ever watched athletes like sprinters, weightlifters or golfers (or maybe you are one yourself), you’ll often notice them clenching their jaw while they perform at high-intensity. Studies have shown that voluntary jaw clenching can improve muscle strength and the performance of motor tasks like strength, coordination, and balance.
This is because these grinding and clenching activities increase cerebral blood flow and stimulate areas of the brain associated with complex motor planning, organization, and regulation. These brain areas include the sensorimotor cortex, supplementary motor area, dorsolateral prefrontal cortex, and the posterior parietal cortex. Grinding and clenching also affect cognitive processes and decision making specifically in the dorsolateral prefrontal cortex.
It’s worthwhile to note that researchers believe that ‘awake bruxism’ (that is, jaw clenching during the day) is more associated with psychological factors such as stress and anxiety, whereas ‘sleep bruxism’ is a more complex phenomenon that is impacted by other neurological and sleep-related factors.
What can you do about jaw clenching?
- Develop awareness of the behavior – If your symptoms tend to be worse in the afternoon or evening, it’s likely that you’re clenching during the day rather than in your sleep, which would lead symptoms to generally be worse in the morning.
- Identify your triggers – Increasing awareness of your subconscious behaviors can be tricky, but when you do catch yourself clenching, take note of what’s happening or what you’re thinking to identify what can trigger your clenching.
- Take a moment to relax – During situations that often trigger your clenching, try to take a 15-20 minute break every hour. If you don’t always have that time, take small 1-2 minute steps to help you relax: listen to soothing music, do deep breathing exercises, or get up and stretch. Your long-term goal is to become more aware of when you clench, and reduce the length of your clenching episodes, so mostly anything that involves the mind and body will help with that.
References
Boroojerdi B, Battaglia F, Muellbacher W, Cohen LG. Voluntary teeth clenching facilitates human motor system excitability. Clin Neurophysiol. 2000 Jun;111(6):988-93. doi: 10.1016/s1388-2457(00)00279-0. PMID: 10825704.
Hasegawa Y, Ono T, Hori K, Nokubi T. Influence of human jaw movement on cerebral blood flow. Journal of Dental Research. 2007 Jan; 86(1): 64-68.
Iida T, Kato M, Komiyama O, Suzuki H, Asano T, Kuroki T, Kaneda T, Svensson P, Kawara M. Comparison of cerebral activity during teeth clenching and fist clenching: a functional magnetic resonance imaging study. Eur J Oral Sci. 2010 Dec;118(6):635-41. doi: 10.1111/j.1600-0722.2010.00784.x. PMID: 21083626.
Manfredini D, Lobbezoo F. Role of psychosocial factors in the etiology of bruxism. J Orofac pain. 2009 Apr 1;23(2):153-66.
