Can A Night Guard Make Your Face Slimmer? We Investigated

Of all the places you can get Botox, I find the jaw to be the most interesting. Known formally as masseter Botox, this injection site holds the promise that delves into functional, not just aesthetic, benefits. 

From reducing clenching and grinding to alleviating tension headaches, masseter Botox has some intriguing well-being perks. From an aesthetic standpoint, it stands out as a quick way to slim down unwanted enlarged facial muscles too. 

On TikTok, some users attribute the dramatic before-and-after slimming effect partly to Botox but partly to something less invasive: wearing a night guard. 

Let's clear up why some people develop enlarged masseter muscles in the first place. 

"The muscles of the face fall into a category called skeletal muscles," says dentist Joshua Pearlman, DDS, ADS. 

"Similar to the muscles in your biceps, you can squeeze the muscles in your face to make different expressions and chew food," he says. And just like skeletal muscles in other parts of your body, everyone's structural makeup is different.

"Some people are born with large facial muscles, which, in turn, give them that 'square jaw' look," he says. 

As cosmetic and restorative dentist Joyce Kahng, DDS, says, many dentists like her can spot the difference between genetic and induced masseter enhancement. "If they're really active and bulging, I know that they are doing something to work those masseters," she explains.

So, can a night guard slim your jaw? I won't lie to you: The quick answer here is not entirely. The majority of the results shown in TikTok videos like this one are from the masseter Botox, not the night guard, says cosmetic dentist Joyce Kahng, DDS.

"Wearing a night guard consistently will not slim the face," seconds facial plastic and reconstructive surgeon Nigar N. Ahmedli, M.D.

However, this doesn't mean you should count the night guard out just yet.

Opting for a combination approach—using a night guard in conjunction with masseter Botox should you choose to take that route—is worthwhile. "The Botox helps the masseter calm down and not work so actively, while the night guard creates a barrier for the teeth," Kahng explains.

Before you run to the drugstore to pick up a night guard, be warned: Some night guards can actually make TMJ worse and cause your masseter muscles to become bigger and more tense, Kahng warns.

"If you wear a bouncy night guard and grind all night, you're actually working out those masseters more because it's just bouncing on that piece of rubber, which can make the joint worse," she explains. "It's like a trampoline for your lower jaw."

Wearing a bouncy night guard like this for just a few weeks won't cause a problem, but consistent use of rubbery night guards could worsen your issues.

Even if you're free from the struggles of TMJ and have zero concern about masseter appearance, a night guard could still be a good idea. In fact, Kahng says, "I believe that almost everyone could benefit from a night guard. That doesn't mean everyone needs one, but it definitely doesn't hurt to have one." 

This is because a night guard can help protect your teeth against accelerated aging. 

"I think of this very much like anti-aging of the teeth. The goal is to keep the teeth from wearing down faster than the rest of your body," she explains. 

The bad news for those who prefer to skip injections is that Botox might just be the most effective way to slim the masseter muscles and ease severe TMJ symptoms. The good news is that night guards can still help and actually bring a host of benefits for oral health, facial structure, and beyond.

While night guards have plenty of benefits, including releasing tension, easing TMJ symptoms, and protecting your teeth, they won't automatically make your jaw appear slimmer. Still, it's a worthwhile step to invest in for your oral care routine.