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Are you grinding your teeth? You could be stressed or have a sleeping disorder

Teeth grinding and jaw clenching – also known as bruxism – could manifest during sleep and even unconsciously in the day.

We cope with stress – consciously and unconsciously – in various ways. Some of us reach for some comfort food to feel better while others hit the gym or head out for a jog to get into the Zen zone. Then, there are the unconscious manners in which we react to stress, such as the peculiar odour our bodies produce under duress. 

Or you may be clenching your jaw or gnashing your teeth unknowingly – a condition known as bruxism – especially when your boss is breathing down your neck for a report.

It's not just stress causing you to do that, depressed individuals may also be prone to teeth-clenching, said Dr Chua Ee Kiam, a senior consultant with the Department of Restorative Dentistry’s Prosthodontic Unit at the National Dental Centre Singapore.

“I would look at the psychological states, as in some cases, depression may also activate bruxism. As high as 38 per cent of the patients seen here were significantly depressed, too, when they reported jaw joint symptoms, which are likely a result of the effects of bruxism,” said Dr Chua.

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In fact, a PubMed article, in which 470 participants were surveyed, also noted that “individuals who grind their teeth tend to report more symptoms of anxiety and depression than non-bruxers”, with bruxism seemingly “more severe during periods of heightened stress and anxiety”.

Why some people develop bruxism when stressed or depressed while others don’t depends on how they perceive and manage the stimulus, said Dr Chua. During sleep, “the subconscious mind may be more active than usual”, he said. And as the mind attempts to solve some of the day’s issues, it may result in gnashing or clamping of the teeth for some individuals.


Some experts term bruxism as the clenching or grinding of the teeth, while others group them together, noted The American Academy of Oral Medicine (AAOM). But no matter what the action is, bruxism can happen in your sleep – and even during your waking hours. In adults, awake bruxism is more prevalent (22 per cent to 30 per cent) than sleep bruxism (1 per cent to 15 per cent), said Dr Chua, because patients are “often aware of the habit in the day”.

Because of this awareness in the day, awake bruxism is not as insidious as sleep bruxism, according to Dr Yue Weng Cheu, the clinical director of DP Dental and DP Dental Orchard. The nocturnal version can be caused by sleep apnoea, which one third of our population is at moderate or severe risk of, he said.

A worrisome form of it is obstructive sleep apnoea when the throat muscles relax during sleep and block the airway to the extent of interrupting breathing. What happens next is, the body sends out a stress response to raise heart and respiratory rates to get in more oxygen, said Dr Yue. Sometimes, this stress response increases muscle activity in the jaw, which in turn, leads to clenching or grinding during sleep.

Sleep bruxism could also be caused by the way you breathe. “Mouth breathers, for instance, condition their tongues to lay low in the mouth during the day and when they continue to mouth-breathe at night, they suffer the consequences of airway obstruction or resistance, resulting in snoring and sleep bruxism,” said Dr Yue.Almost every patient who suffers from sleep bruxism is unaware of his or her habit unless the sleeping partner complains about the noise at night, said Dr Chua.


The prevalence of bruxism is higher in individuals from ages 30 to 49 than those older than 60 years old, said Dr Ho Kok Sen, a dental specialist in oral and maxillofacial surgery at Specialist Dental Group, Mount Elizabeth Hospital. "According to AAOM, the prevalence of bruxism tends to decrease with age, with the lowest in people over 65," he said.

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So, how common is bruxism? Dr Chua sees about 10 to 20 cases every month, while Dr Yue handles about four cases a week on average. Age is not a factor as both doctors have patients of various ages.


Is there pain in your temporomandibular joint (a hinge-like joint that connects your jaw to the skull) – especially in the morning when you wake up? While brushing your teeth, take a look in the mirror: Are your teeth looking shorter than before?Take note, too, when you’re eating; is there pain or sensitivity when you chew? Do you notice a change or misalignment in your bite, or you just can’t bite properly anymore? Or you can’t fully open your mouth? If you answered “yes” to any of the above, it’s time to check in with your dentist for bruxism.

Clenching typically cracks your pearly whites and causes muscle soreness, pain and damage to the jaw. On the other hand, grinding wears off the outermost protective enamel and exposes the nerve-rich dentin, which results in tooth sensitivity, noted AAOM.

“Sometimes, we don’t see the grind marks or facets clearly but we can detect craze lines (cracks in the enamel) in the teeth,” said Dr Yue. But by the time the craze line has developed into a crack (involving the enamel, dentin and pulp of the tooth) and has joined with the other cracks, the patient has already worn down his teeth to the point of breakage, he said.

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The duration it takes to wear down your teeth depends on the thickness of your teeth's enamel, said Dr Ho. "People who have weaker tooth enamel will having a higher risk of teeth breakage if bruxism persists." 

Dr Yue added that it is "hard to tell how long that takes but those with the habit of cracking open crab shells, nuts, ice cubes and chicken bones with their teeth run higher risks”. 


Save for the scenario when you can’t fully open your mouth and require surgery to “unlock” the jaw, you’ll likely need root-canal and crown treatments, said Dr Chua, and sometimes, extraction.Meanwhile, wearing a mouth guard may help to minimise the wear and tear. But do not grab one off the shelf. “Using a mouth guard from the sports store is like using a pair of shoes you picked up on the street,” said Dr Yue, explaining that the dentist needs to customise the fit for you. “If the fit is not good, the muscles will suffer.”

In addition, "over-the-counter mouth guards are generally made of thinner materials, which may not be able to withstand the force if your clench or grind is extremely hard", said Dr Ho.

However, a mouth guard doesn’t directly address the root cause of bruxism, said Dr Yue, which can sometimes be traced to sleep-related breathing disorders. Moreover, an upper guard should not be used during sleep if the patient has breathing disorders. “This is because the upper guard will block the tongue from lifting to the palate and that can aggravate the obstruction of the airway, leading to a more disastrous outcome,” he explained.

Botox injections to reduce the muscular actions in the jaw may help temporarily, said Dr Chua. Other than those, he suggested keeping stress levels under control and leading a balanced lifestyle.

Source: CNA/bk