Bruxism: Causes, Symptoms and Treatments for Teeth Grinding

22 June 2022

 Quiz time: Do you know which is the strongest muscle in the human body? Hint: it’s related to bruxism and chewing!


masseter muscle

Position of the masseter muscle in the head.


Answer: The strongest muscle in the human body is the masseter muscle, one of the four muscles involved in chewing.


The masseter muscle is also one of the strongest muscles in the body and the force of the human bite is approximately 70 pounds (approx 30 kg) per square inch! Having a strong bite force helps with chewing our food but in a condition called bruxism where teeth grinding occurs, medical problems such as headaches, migraines, sleep apnea and dental problems like tooth fracture and hypersensitivity can result.


Bruxism can occur in the day and night and often, people who suffer from teeth clenching are unaware of it until they develop problems from it… like my husband. This post on bruxism will feature him as a case study. Some of you might have seen on my Instagram stories that I had to administer jaw botox to Dr Gerard Ee’s masseter muscles because his years of jaw clenching caused a tooth fracture. Besides fixing his cracked tooth, treating the underlying cause i.e. sleep bruxism is also a priority to prevent such dental problems from worsening.


jaw botox for teeth clenching

 Marking out safety boundaries and injection points before starting on botox injections for Dr Gerard Ee’s masseter muscles.


Botox jaw injections for teeth clenching/ bruxism also helps with slimming the jaw. You can see how I administer botox jaw injections in this blogpost Jaw Reduction Botox and Chin Filler Review. This blogpost will focus on bruxism and how you can stop grinding teeth or clenching jaws.


This post will cover:

 • What is bruxism?

•  What are the side effects of bruxism/ teeth clenching/ jaw grinding?

•  Why does bruxism/ teeth clenching/ jaw grinding occur?

•  How do I know if I have bruxism or grind my teeth?

•  How can bruxism/ teeth grinding be stopped?

•  Botox jaw/ masseter injections for teeth clenching/ grinding

•  Mouth/ night guard for bruxism


what is bruxism


What is bruxism?


Bruxism refers to repeated teeth grinding or jaw clenching1. The diagnosis of bruxism is clinical and usually investigations such as scans are not required to confirm the diagnosis. Usually, the patient or roommate/ partner reports awareness of teeth grinding and this is confirmed by the doctor based on signs. These signs include masseter muscle hypertrophy (i.e. large jaw muscles; this is why jaw botox helps to slim the masseter muscles) and damage to the teeth1.


Bruxism can occur when awake (i.e. awake bruxism) or during sleep (i.e. sleep) or both. Understanding this distinction is important for treating teeth clenching. With awake bruxism, there is usually awareness from the patient. Awake bruxism is also linked to emotional stress. Sleep bruxism is when the teeth grinding or clenching occur during sleep. The patient may or may not recall the teeth grinding but may notice signs such as tightness and soreness in the jaw on waking up. Common room partners may notice the teeth grinding.


effects of bruxism on dentition

Effects of bruxism or teeth grinding on dentition.


What are the side effects of bruxism/ teeth clenching/ jaw grinding?


Teeth clenching and jaw grinding affects the teeth, jaw muscle and overall health.


Long term teeth grinding causes wear and tear of the teeth and gingiva. Jaw clenching has been shown to cause cracked tooth syndrome, increased tooth mobility and hypersensitivity. Gum recession, temporomandibular joint (TMJ) disorders and jaw discomfort are also caused by jaw clenching1,2.


Teeth clenching also results in hypertrophy of the masseter muscles which can cause muscle spasms, muscle aches and headaches3-6. From an aesthetic perspective, masseter muscle hypertrophy makes the sides of the face look wider or square faced. This is the premise of jaw botox to slim down the sides of the face.


causes of bruxism



Why does bruxism/ teeth clenching/ jaw grinding occur?


Teeth grinding is affected by many factors including genetics and emotional stress,3,7,8. If you have a type A personality, take note that you are at increased risk of jaw clenching9 (note to self: relax!).

Some of the risk factors for teeth clenching are related to:

Lifestyle factors e.g. smoking, caffeine intake, certain medications and drugs8.

Medical conditions e.g. gastroesophageal reflux disease (GERD) and obstructive sleep apnea (OSA)8,10


How do I know if I have bruxism or grind my teeth?

If you have awake bruxism, you might notice the jaw clenching in the day, especially during moments of emotional stress and pressure. With sleep bruxism, you may not be aware of the jaw clenching behaviour as you are asleep. Your spouse, children or common room partner may notice your teeth grinding behaviour.


masseter muscle

 Hypertrophy of the masseter muscles is associated with bruxism.


With teeth grinding or teeth clenching, you may notice these signs:

• Jaw muscle pain or ache on waking

• Enlarged jaw muscles (masseter muscle hypertrophy).

If you’re unsure, place your fingers at the sides of the back of your jaw and clench your teeth. If your muscles ‘pop’ out or feel significantly larger you might might grind your teeth or clench your jaw

• Dental: your dentist may highlight abnormal wear and tear of your teeth and you might even crack your teeth.


How can bruxism/ teeth grinding be stopped?


The medical treatments for teeth clenching or jaw grinding centered around 2 objectives:

1. Stop the jaw clenching or teeth grinding behavior e.g. jaw botox injections for teeth clenching, behavioural therapy and medications.

2. Protecting the teeth from further damage e.g. oral splints/ night guard.


The two most common treatments in Singapore for treating jaw clenching or teeth grinding are: jaw/ masseter botox injections; and night guard. I’ll discuss botox for teeth clenching and night guards in greater detail.


jaw botox for bruxism or masseter hypertrophy

How botox jaw injections works for bruxism/ teeth grinding and masseter muscle hypertrophy.


Masseter Botox for Jaw Clenching

Botox (botulinum toxin) is one of the ways of treating teeth clenching especially with sleep bruxism. It also has thel benefit of slimming the jaw for a more defined jawline for both males and females.


Studies have shown that jaw botox injections are effective in treating bruxism and relieving the pain caused by teeth grinding11-14. Botox relaxes the jaw muscles partially to relieve clenching action and tension in the jaw (masseter muscles). The results are usually seen in approximately 1-2 weeks after jaw botox injections.


Botox physically stops the masseter muscles from clenching by inhibiting the release of neurotransmitter acetylcholine at the neuromuscular junction. Just like a muscular body builder who stops exercising, muscle bulk is gradually lost and the masseter muscles at the sides of the jaw become slimmer. The actual slimming of the jaw/ masseter muscles occurs over 4 to 6 weeks.


Does Botox jaw injections for teeth clenching hurt?

No it does not hurt! The needles I use in my clinic for botox jaw injections are very fine and you get numbed beforehand.


How long do botox jaw injections last?

The results of botox for jaw clenching last 4-6 months on average.



When can the results of botox jaw injections be seen?


The results of botox jaw injections for jaw clenching kicks in 1-2 weeks after the injections. You should notice that the teeth grinding is reduced and the jaw muscles feel softer and less tense.


In terms of jaw slimming, it will take 4-6 weeks after botox jaw injections to the masseter muscle.


How many units of botox are required for jaw clenching/ teeth grinding/ bruxism?


It depends on the severity of bruxism and masseter muscle hypertrophy. On average, 24 to 36 units of Botox to each side of the jaw muscle.


Please note that the conversion of Botox to Dysport is not equal; 1 unit of Botox is approx 2-3 units of Dysport.


Jaw botox injections; here we go!


How are botox jaw injections for jaw slimming/ teeth clenching performed?


My post A Guide to Slimmer V Face: Jaw Reduction Botox will show you how I do it in my clinic in Singapore. Essentially after I evaluate the patient, make measurements and numb the patient jaw muscles, it’s just 2-3 injection points on each masseter muscle.


Botox for jaw clenching is done within 15 minutes.

Is there downtime for jaw botox for bruxism?


None. There is no redness, bruising or obvious needle marks because I use very fine needles.


Is botox for teeth clench or grinding safe? What are the side effects or complications with botox jaw injections?


Botox jaw injections have been shown to be effective and safe with very low risk of side effects and complications15,16. If you are concerned about the safety issues of Botox and if jaw botox injections can lead to an overdose (no, not at all), this post Is Botox Deadly? will review some of the safety concerns regarding Botulinum toxin injections.


The side effects of botox jaw injections are: weakened chewing; asymmetrical facial expressions; and uneven bulging of the masseter muscles. Some of the ways that you can minimise your risk of complications from botox jaw injections is to follow through post treatment instructions from your doctor and choose an experienced doctor. A doctor with a good understanding of facial anatomy and experience will ensure best results for your botox jaw injections.


Will botox jaw injections affect my smile?


Botox injections to the masseter muscle for bruxism/ jaw slimming should not affect your smile. However, the side effect of unnatural smiles due to botox jaw injections have been reported. If jaw botox affects smiling, this is because the risorius muscle has been affected, likely due to unwanted diffusion of botulinum toxin.


The risorius muscle normally lifts the corners of the mouth. If the risorius muscle is weakened due to botox injections, the smile may look asymmetrical. There are injection techniques and safety zones to respect to minimise this risk with botox jaw injection. However, if this rare complication occurs, it is temporary and will disappear when the effects of botox wear off.


Are botox jaw injections for bruxism permanent?


No, jaw botox for jaw clenching is not permanent. The result of botulinum toxin lasts 4-6 months. The habit of teeth grinding may return and you may need to get your jaw clenching treated again.


With awake bruxism or teeth grinding, the habit may be easier to quit as you might be aware of teeth clenching actions, especially during periods of stress. With sleep bruxism, the teeth clench behavior is usually not cured and recurrence happens when the effects of jaw botox wear off17,18. It is almost impossible to stop the jaw clenching action as you are asleep and unaware of the teeth clenching action. Treatment for nocturnal/ sleep bruxism is long term, whether you are using night guards or botox jaw injections.


Dr Ee’s night guard for bruxism


Mouth/ Night Guard for Bruxism

Oral splints for bruxism aim to protect the teeth and temporomandibular joint from further damage due to bruxism. These splints are commonly known as night guards or occlusal bite guards.


Night guards may vary slightly in appearances and properties, but in essence most of them are hard acrylic-resin stabilization appliances, mostly worn in the upper jaw19,20. Hard splints (night guards) are preferred over soft splints as soft splints may worsen bruxism in some instances20. However, hard night guards are more uncomfortable than soft mouth guards. You have to use the night guards consistently for the teeth to be protected, so the discomfort affecting compliance is a drawback of night guards vs jaw botox for bruxism.


Tips for getting used to your mouth night guard for bruxism (as shared by our trusted dentist who treated Dr Gerard Ee’s cracked tooth syndrome):

• Check the fit of your mouth night guard after getting it fabricated with your dentist

• Wear the night guard 30 minutes before bedtime so that you get better adjusted to the discomfort and it is less likely to disrupt your sleep.


Jaw botox vs night guard for bruxism: what are the differences?

Night guards and jaw botox injections for the treatment of bruxism work differently. Night guards are oral splints that are worn over the teeth at night, on a daily basis, to protect the teeth from damage due to grinding or clenching. It does not stop the action of the masseter muscles from clenching. Patients must be compliant with the use of their night guards for the mouth guard to be effective.


Jaw botox injections partially paralyse the masseter muscles to prevent the jaw muscles from clenching or grinding the teeth. The effects of jaw botox injections last 4-6 months and you may need to repeat them with your doctor again.


Can I have jaw botox injections and also wear a night guard for bruxism?

Yes, you can because jaw botox and night guards are not mutually exclusive. In severe cases of bruxism, combining jaw botox and the use of night guards is very helpful.


I have encountered patients, often referred to me by dentists, who have bruxism so severe that they cracked or grinded through their retainers. Botox injections to the masseter muscles will be very useful in such patients to stop the action of grinding so that they can protect their teeth and retainers.


Jaw botox is also about achieving a balance between preserving functions of the jaw (namely biting chewing of food) and eliminating unwanted movement (i.e. teeth clenching in bruxism). If excess botox is injected into the masseter muscles, chewing could be weakened… botulinum toxin isn’t necessarily better with higher doses. Safety is always a priority. In severe cases of bruxism where jaw botox is still inadequate in stopping the grinding action, using a night guard will be very helpful.

Conclusion on bruxism and treatments to stop teeth clenching


Bruxism or teeth grinding, can happen when you are awake and/or asleep. Sleep bruxism is harder to treat. If left untreated, long term teeth grinding or clenching can cause dental problems like tooth fractures (cracked tooth syndrome), hypersensitivity, gum recession, headaches, migraine and temporomandibular joint disorders. From an aesthetic perspective, masseter hypertrophy (enlarged jaw muscles) can occur and it makes the jawline lose its definition and the face look larger or squarish.


There are a couple of reasons why bruxism or teeth grinding occurs; and stress is one factor. Bruxism, especially sleep bruxism, is hard to treat. Two of the most common medical treatments for bruxism in Singapore are: botulinum toxin to stop the jaw clenching and mouth/ night guard to protect the dentition. Both can be combined in severe cases.


So if you’re still wondering what happened to our case study in this blogpost, Dr Gerard Ee, and his cracked tooth syndrome? His dentist diagnosed Dr Gerard Ee’s years of bruxism as the cause of his cracked tooth and showed us close up photographs of the wear and tear on Dr Gerard Ee’s teeth.



To treat Dr Ee’s bruxism, I injected botox into his masseter muscles to sleep bruxism and Dr Ee also had a night guard fabricated. He’s not compliant with his night guard daily because of the discomfort and so the jaw botox helps to prevent further grinding. Dr Ee’s masseter muscles at the sides of his jaw have also slimmed down, so his jawline is more defined now too, and he’s very happy with these results.


The treatment for cracked tooth syndrome is beyond the scope of my expertise (check with your dentist!) but I’ll share with you the fate of Dr Ee’s long suffering dentition. The cracked tooth was banded to determine if the crack was favorable or unfavourable. His cracked tooth turned out to be an unfavourable crack so the tooth needed a root canal (ouch). Lesson of the day: Early prevention is better than disease treatment; as with all things in medicine!


I hope that you have found this review on bruxism and the management of teeth clenching/ grinding useful! Dr Gerard Ee guest starred as a case study in this on bruxism and I hope that this made learning for you fun. (If you found this post fun, you might enjoy reading about my experience with getting my hair loss treated with Regenera Activa. Dr Gerard Ee injected my scalp this time!)


Related blogposts:

Botox vs Fillers: the Differences

NoTox: Non-invasive Botox Alternatives



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