Sleep bruxism (or teeth grinding or clenching during sleep) is a common condition that affects approximately 1 in 10 adults. Since it happens in one’s sleep, people often have no idea if they grind or clench their teeth.
Teeth grinding vs. teeth clenching – what’s the difference?
Teeth grinding and clenching are both jaw movements that happen during a sleep bruxism episode. In sleep studies, researchers see three distinct types of movements:
- Phasic episodes (rhythmic teeth grinding)
- Tonic episodes (clenching)
- Mixed episodes (a mix of phasic and tonic)
Teeth grinding produces a characteristic sound while teeth clenching tends to be silent.
In teeth grinding, the jaw muscles are moving your jaws and teeth side-to-side or front-to-back rhythmically. This causes your upper and lower teeth to grind against each other, producing the characteristic teeth grinding movement.
This is also often accompanied by the squeaky, cracking, crunching sound that is created when two hard objects (your teeth) rub against each other. Most teeth grinders have never heard this sound before as they are asleep when it happens. But their partners, or whomever is sleeping next to them, will hear these loud teeth grinding sounds. The strange noise can be quite unsettling, especially if they didn’t know where the sound came from.
On the other hand, clenching is when your jaw muscles are contracted (tensed) and stay that way throughout the duration of the episode, which can be as short as a few seconds, or can last up to a minute. The whole time you are clenching your teeth, your upper and lower teeth are pressed against each other with micro-movements back and forth, and a force than can be up to 10x the force of chewing.
Despite the immense amount of force involved, teeth clenching does not produce the same sound characteristic as teeth grinding. They tend to be silent, and your partner probably won’t notice any sound while you’re sleeping. However, those who unconsciously clench their teeth in their sleep tend to report substantial muscle soreness, jaw pain, and headaches in the morning. It has been hypothesized that these painful symptoms are a result of the muscles being in a tense, contracted position for a long period of time during the night.
Why does it matter?
It is believed that teeth grinding causes more damage to your teeth (visible tooth wear, chipped teeth, teeth sensitivity, early failure of implants, prostheses, etc.) than clenching as clenching causes more damage to the musculature and temporomandibular joints.
One study from Japan showed a significant correlation between teeth grinding frequency and duration (especially episodes that produce teeth grinding sounds) with extreme tooth wear, to the point where the dentin layer is exposed. Simply put, those who frequently grind loudly – as reported by their partner or family member – are more likely to see significant wear to their teeth than those who do not often grind loudly. This is especially concerning not only because of its cosmetic effect, but also because extreme tooth wear can cause teeth sensitivity and pain (if the nerve-rich layer of the teeth become exposed as a result), as well as long-term structural damage.
The same study also showed that participants who experienced sore or painful jaw muscles in the morning tended to clench for longer periods of time. Other studies have seen differing results where extreme teeth grinders, despite having longer and more frequent bruxism episodes at night, do not experience any painful symptoms. On the other hand, those with shorter duration of teeth clenching complain of noticeable facial pain and headaches in the morning. This goes to show that each person’s situation may differ depending on a range of factors.
How do I know if I’m a grinder or a clencher?
Well, to be 100% sure, you have to undergo a sleep study in a sleep lab, or use a portable electromyography (EMG) device that can measure your jaw muscle movements.
But, you can also deduce if you’re a grinder or a clencher from your symptoms.
Teeth grinders are more likely to learn about their condition from their dentists, who might notice:
- Excessive tooth wear
- Increased tooth sensitivity
- Fractured or chipped teeth
- Early failures of prosthesis (implants, crowns, etc.)
In addition, teeth grinding is more likely to produce audible sound (grinding noise) compared to clenching. So if a bed partner or a family member / friend has heard teeth grinding sounds while you are sleeping, it’s very likely that you are a teeth grinder and not a clencher.
One thing to note: tooth wear is also accelerated by acidic diet. So if you know you’re a severe teeth grinder, you should probably also take a examine your dietary and drinking habits. Try to avoid acidic food or drinks (juices, soft drinks), drink plenty of water, and rinse your mouth after eating or drinking. Try to avoid acidic food, drink plenty of water and rinse your mouth after eating.
If your symptoms consist of muscle soreness, facial pain, earaches, and headaches that are worst in the morning, then you are most likely a clencher.
Clenchers tend to have the following symptoms:
- Pain or fatigue of the jaw muscles
- Tenderness while chewing
- Headaches – usually in the temples
- Tinnitus or earaches
- Sore neck
Now that you’ve learned the difference in symptoms between teeth grinding and teeth clenching, you should be able to identify which type you are and respond accordingly.
