Does Clenching Your Teeth/jaw Make Jaw Muscles (Masseter Muscles) Bigger and Bulge out?

many people who have large cheeks, especially the lower cheek, are affected by hypertrophic masseter muscles from clenching. This can sometimes cause a painful TMJ, or temporo-mandibular joint syndrome. Relaxation of these muscles are often curative and Botox can be used to relax these muscles. There can be risks of asymmetric treatment.

Absolutely - If your muscle is constantly under tension, it will become more prominent.  Weakening the masseter muscle keeps you from clenching your teeth as tightly.  Weakening the muscle can 1) save your teeth, 2) reduce neck/headaches, 3) help you open your mouth better.

Just like any muscle on your body, if you frequently contract your muscles in the jaw then they will get stronger and thus more prominent.

Hi and thank you for your question. Ironically, we see a great number of patients who complain of the action itself (sore jaw from clenching at night, or grinding teeth) as well as the appearance or change in facial shape. Small doses of Botox is an excellent treatment option to soften, relax, and return facial shape, often providing relief in all areas of concern. If you have a Botox provider already, be sure to ask about this treatment and if you do not already have a provider, I suggest that you pursue a consultation and learn more about how it works, what to expect, results and longevity, and inquire about dosage and cost of treatment. In our experience, patients are very happy with this treatment option.

Yes, in a sense clenching your jaw and/or grinding your teeth will strengthen those muscles, thereby increasing the size causing potential bulging. Botox is commonly placed in the masseter muscles to lessen the strength and size, and results in a desirable facial contour.

Hi alexandercruz91, 
Thank you for your question! 
Yes, jaw clenching and teeth grinding can absolutely enlarge your masseter muscles. The more frequently you are contracting the muscle the stronger it gets and larger it will become, we refer to this as muscle hypertrophy. 
Botox or Dysport to the masseter muscle will weaken the muscle and, with time, cause the muscle to diminish in size. With the muscle weaker, patients will notice a decrease in their jaw clenching/teeth grinding while finding relief from the symptoms of TMJ. Aesthetically it is also a great treatment for anyone looking to improve their facial shape, slim their face, or better define their jawline. 
I've created a video that reviews Botox/Dysport treatment to the masseter muscles, I hope you find this helpful in your research! 

Thank you for your question alexandercruz91. I understand your concern. Botox is a purified protein used to address wrinkles associated with facial expression. When injected into the skin Botox will relax the muscles and smoothen out the overlying wrinkles. The most common areas of treatment are in the upper face. These include the horizontal lines seen on the upper forehead when one raises the brows, the vertical lines seen between the brows when one frowns (frown lines), and the crow's feet seen around the eyes when one smiles.It is difficult to make an assessment without a formal exam in the office where I can view the skin in multiple angles and observe wrinkles formed with facial expression. However, I hope the information provided here is useful.Botox can be placed in the masseter muscle in the lower face to contour the lower face and address pain associated with TMJ. In this area 20-40 units of Botox are used per side. Depending on the reason for the enlargement of the muscle, permanent results may be achieved. For example, some people have a habit of grinding, clenching, or biting their teeth subconsciously. Often times this happens in their sleep when they are not aware of it. Botox placed in this muscle will relax the muscle and the grinding, clenching, and/or biting will decrease. This will reduce the size of the muscle. If the brain gets accustomed to this and the person stops grinding, clenching, or biting, then the muscle will not become enlarged or as enlarged again. However, if the habit starts again, the muscle will likely get larger.

To determine if someone is a good candidate for this treatment it is necessary to look at a person’s lower face when biting and comparing it to when the person is not biting. If a bulge is seen on the outer portion of the jawline, then the person is likely a candidate. It can also be felt with the fingers when biting.
With any injection, there are risks such as pain, bleeding, bruising, redness, swelling, tenderness, and infection. We take special precautions to minimize these risks such as using a painless technique. We also treat bruises with a laser as early as the next day. Bruises usually resolve within two weeks if untreated. After a laser treatment bruises usually resolve in 1-3 days, but may still take two weeks for full resolution. In addition to these risks, with Botox there is also a risk that the product spreads or diffuses to nearby structures. Spread to nearby muscles can lead to side effects such as the temporary appearance of droopy eyelids or a temporary asymmetric smile.

After a Botox treatment, I recommend that my patients avoid heat exposure, alcohol consumption, and strenuous exercise for 24 hours and not lie down flat for four hours. This is because all of these activities may possibly lead to the movement of the product and consequent side effects such as droopy eyelids. Although there have been no definitive studies shown that these actually occur and some physicians do not provide such aftercare instructions, in the absence of data I err on the side of caution and recommend that my patients avoid such activities.

Please consult with a doctor for specific recommendations. Good luck!

The masseter muscle is used during every day movements such as chewing. The masseter muscle can become overdeveloped if a person uncontrollably grinds their teeth at night or clenches their jaw often. This can sometimes lead to a square-shaped, enlarged lower third of the face. Patients who come to us with that sort of complaint can receive Botox Cosmetic or Dysport injections in attempt to weaken those "jaw-clenching" muscles. The goal of this type of treatment is to slim the lower portion of the face. Botox Cosmetic or Dysport injections must be given every 3-4 months for optimal results.

Yes. Clenching teeth, or "grinding you teeth" can cause the masseter muscle to get bigger, or "hypertrophy". The masseter muscle is one of the muscles activated during chewing. It’s located at the “angle of the mandible”, or “angle of the jaw”. Masseter muscle hypertrophy is enlargement of the masseter muscle, and can contribute to a harsh, square look at the angle of the jaw. Botox can be used to relax this muscle, and to soften the look of the lower face. I usually start with 50 units of botox (25 units on each side). When Botox is used to relax the facial muscles that cause fine line, the maximum effect is seen in 7-10 days. When Botox is used to reduce masseter muscle hypertrophy, the maximum effect is not seen for 3 months. Results can last up to 9 months. I recommend repeat injection every 6 months if you would like to maintain your results. 

Yes, clenching your teeth regularly with make your masseter muscles more prominent and give you that 'square jaw' look and Botox is useful in reducing the size and function of the masseter muscle. Repeat treatments will be necessary to achieve this goal..