Jaw Clenching, Teeth Grinding and Masseter Treatment

If you clench your jaw or grind your teeth, a neuromodulator injected into the masseter, the main chewing muscle, may reduce the force of clenching and ease related jaw tightness for some people. It is not a cure for bruxism, and it tends to be most useful as part of a plan that includes your dentist. Over time, relaxing a large masseter can also make the lower face look slightly narrower.

Understanding bruxism

Bruxism is the medical term for clenching or grinding the teeth. It can happen while you are awake, often without noticing, during concentration, stress or physical effort. It can also happen during sleep, when it is harder to control and is often first noticed by a partner or a dentist.

Signs that you may be clenching or grinding include:

• Jaw soreness or tightness, especially on waking.
• Headaches around the temples.
• Worn, chipped or sensitive teeth.
• Clicking or discomfort at the jaw joint in front of the ear.
• A firm, bulging muscle at the angle of the jaw when you bite down.

Causes vary and often overlap. Stress and anxiety, sleep disorders such as sleep apnea, certain medications, caffeine, alcohol and the way the teeth fit together may all play a part.

Why the masseter matters

The masseter is a thick muscle on each side of the face, running from the cheekbone to the angle of the lower jaw. You can feel it tighten if you place your fingers just in front of your earlobe and clench your teeth.

Like any muscle that works hard, a masseter that clenches repeatedly can grow larger. This is called masseter hypertrophy. It can give the lower face a square or wide appearance and may contribute to a feeling of constant tension.

How neuromodulator treatment works

A neuromodulator such as botulinum toxin type A reduces the strength of the muscle it is injected into by blocking the nerve signal that triggers contraction. For bruxism, a measured dose is placed into a few points within the lower part of each masseter, away from the muscles that control your smile.

You can still chew, talk and eat normally. The aim is to reduce the intensity of clenching, not to stop the muscle from working. Many people notice less jaw tightness within one to two weeks. Some also report fewer tension headaches, although results vary.

The use of neuromodulator for bruxism is supported by a growing number of studies, but the evidence is still mixed and not as strong as for facial lines. It is considered an off-label use in Canada, which means it is not one of the officially approved indications. Your physician should explain this clearly at your consultation.

Working with your dentist

Injections reduce muscle force, but they do not protect your teeth on their own or address every cause of grinding. A dentist plays a key role by:

• Checking for tooth wear, cracks and problems with the jaw joint.
• Fitting a custom night guard to protect your teeth during sleep.
• Assessing your bite and recommending further treatment when needed.
• Suggesting referral to a specialist for jaw joint disorders when appropriate.

If you snore loudly, wake unrefreshed, or a partner notices pauses in your breathing, mention it to your family doctor. Sleep apnea can be linked with night-time grinding and is important to diagnose in its own right. Stress management, reducing caffeine and alcohol in the evening, and jaw-relaxation habits during the day may also help.

The slimming effect: a side benefit, not a promise

When an enlarged masseter is relaxed repeatedly, it may gradually become smaller from reduced use. This can soften a square jaw and make the lower face appear slimmer. The change develops slowly, typically over several weeks to a few months, and is not seen in everyone.

Some people seek treatment for this reason alone. That can be appropriate after careful assessment, but it is important to know that the width of your lower face also depends on bone structure, fat and skin, which injections do not change. If you are also interested in how the lower face looks in profile, our article on jawline and chin filler explains a different approach.

How long it lasts

The effect on clenching typically lasts three to six months. Some people find that with repeated treatment, results last a little longer. Treatment is usually spaced at least three months apart to reduce the risk of the body developing resistance to the medicine.

Who should avoid or delay treatment

Treatment is not recommended during pregnancy or breastfeeding, for people with neuromuscular conditions such as myasthenia gravis, or for anyone with a known allergy to a botulinum toxin product. It should be postponed if there is infection in the area or an untreated dental problem causing pain. Jaw pain that is severe, sudden, or comes with swelling, fever or difficulty opening your mouth should be assessed by your family doctor or dentist first.

Possible side effects

Common effects include tenderness, bruising and a feeling of tiredness in the jaw when chewing tough foods for the first few weeks. Less commonly, the product can affect nearby muscles and cause an uneven or altered smile, which is temporary. Some people notice that, as the muscle slims, the skin over the lower cheek looks slightly hollower or less firm, which is more likely in people with thinner faces or looser skin.

Frequently asked questions

Will I still be able to chew normally?

Yes. Some people feel a little fatigue when chewing very tough foods for a few weeks, but eating and speaking are not affected for most.

Can I stop wearing my night guard?

No. Keep wearing your night guard unless your dentist advises otherwise. Injections reduce force but do not fully protect your teeth.

Does this help jaw joint (TMJ) problems?

It may help muscle-related jaw pain in some people, but jaw joint disorders have many causes and should be assessed by your dentist or doctor before treatment.

If clenching or a tight jaw is bothering you, a consultation at HealthPark Medical Aesthetics allows a physician to examine your jaw muscles, review your history, and talk about whether treatment is appropriate alongside care from your dentist.