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How Do I Know If My Night Guard Fits Properly?

A night guard is an oral appliance that you wear over your teeth to protect them from grinding and clenching damage. While wearing it in your mouth, it's a given that it will feel different than without it on.

Night guard for teeth grinding
Night guard for teeth grinding

Do you know if your night guard is fitting the way that it should be? We will discuss some of the signs of a well-fitting night guard and an ill-fitting one as well. If it is the latter, you may need the dental appliance to be adjusted or even remade for the worse case scenarios.

Table of Contents:

Well-fitting night guard signs

A properly fitted night has a couple of distinctive signs and it may feel foreign at first but over time it should become more comfortable. When our patients get used to wearing it, they often tell us that it feels "weird" if they don't wear it to sleep.

How a night guard should fit:

  • Your lips should be comfortably touching.

  • The bite feels well balanced, they touch on both sides.

  • It doesn't feel too tight nor too loose.

  • Your jaw feels less sore when you wake up in the morning.

Note: If your night guard fits well, you should have all of the above four signs. If you are lacking in any of them, it may be an indication that a trip to the dentist is warranted. That means you may need an adjustment!

Lips are comfortably touching

A night guard that fits properly should allow your upper and lower lips to touch comfortably.

  • Both lips will touch when you're relaxed.

  • You shouldn't need to forcibly make them touch.

What this means for you: It is an indication that your oral appliance is the right size for your mouth because it permits you to close your mouth. If it was too big for you, you would not be able to get your lips to touch and consequently not be able to close your mouth.

Bite feels balanced

Your bite should feel balanced when you are wearing the mouth guard.

  • The occlusion on both sides of your jaw, left and right, should feel fairly even when biting down.

  • One side shouldn't be touching or biting down harder than the other side.

  • Both sides should be touching, if only one side is touching then that is wrong.

What this means for you: It is an indication that the night guard is made harmoniously with your natural bite. If it wasn't fitting well, your bite would feel off. Therefore, a balanced sensation is what you should strive to look for.

Not too tight, not too loose

The nightguard should not feel too tight nor should it feel too loose. This is kind of like the three little bears analogy where it should feel "just right."

Signs of not too tight:

  • Mild pressure but not painful.

  • Teeth do not feel like they've had a workout when you wake up.

  • You shouldn't feel like you want to rip the appliance out of your mouth.

Signs of not too loose:

  • It shouldn't fall out of your mouth.

  • You shouldn't need to keep pushing it back into place.

Jaw feels less sore in morning

A tell-tale sign of a night guard that is working and one that fits properly, is when you wake up in the morning and your jaw feels better.

  • Jaw feels less sore.

  • The muscles feel less tender,

  • Head feels less pressure and more relieved.

  • You've had a better sleep.

  • Less jaw popping and clicking.

If you notice these signs, you should feel confident that you made the right choice in having this guard for your mouth made. Your symptoms are being alleviated by wearing it at night.

Ill-fitting night guard signs

An ill-fitting night guard presents with some distinct signs to let you know that it doesn't fit very well. They will often feel awkward or out of place as if it just doesn't feel right.

Below is a list of potential signs and symptoms for when it doesn't fit properly.

Signs of a poorly fitting night guard:

  • You are unable to close your mouth while wearing it.

  • It feels too tight.

  • It feels too loose.

  • Only a few of your teeth touch when you have it in your mouth.

  • It doesn't even fit over your teeth.

  • It feels like it is pinching on your gums.

Can't close mouth

While wearing the night guard, you are unable to even close your mouth.

  • Your lips don't touch when they're relaxed.

  • You have to forcibly try to get the lips to touch.

  • Feels like your mouth is propped open.

bad fitting night guard unable to close mouth
unable to close

These are all indications that the oral appliance is too big for the size of your mouth. You should have it adjusted by reducing the size of it so that it is sized properly for your oral cavity.

Feels tight

When you wear the mouth guard, it feels extremely tight.

  • Teeth feel uncomfortable when you're wearing it.

  • Dentition feel sore or tender once you take it off.

  • Feels difficult for you to remove the night guard.

These are all signs that maybe it was made too tight. Fortunately, the tightness can be reduced and the pressure can be alleviated by adjusting the interior of the prosthesis.

Feels loose

A sign of a bad fitting night guard is if it feels loose when you wear it.

  • It feels like it is about to come off when you're wearing it.

  • It falls out of your mouth while you're asleep.

  • You keep having to push it back up into place.

Unfortunately for a loose fitting mouth guard, it cannot be adjusted. You will need a brand new one to be made in order to correct the looseness.

Only a few teeth touching

When you wear the night guard, not all of your teeth are contacting the prosthesis.

  • It feels like only a couple of the teeth are touching it.

  • It could also be that only one side of your jaw touches it

  • Overall, your bite feels unbalanced or "off".

This is an indication that your mouth guard is not in harmony with your natural bite. You should be able to have this adjusted so that your bite feels more even.

Won't fit over the teeth

A tell-tale sign of a poorly fitted night guard is if it doesn't even fit over your teeth. What we mean by this is that you can't even wear it. When you try to wear it over your teeth, it doesn't even work. You're literally unable to get it onto your teeth.

Unfortunately the only solution to this is to have it remade. A potential cause for this is if your teeth have shifted. If you don't wear it every night, your teeth may shift and then it won't fit any more. For mouth guards to fit you have to wear it every night or at the bare minimum, a couple of times a week.

Gum pinching

Gum pinching is when the night guard is too long and it is encroaching upon your gingiva. This will feel like the oral appliance is literally squeezing your gums.

Signs its pinching the gums:

  • There could be an indentation on the gums after you take it off.

  • The gums are blanching (turning white) when you're wearing it.

  • Gums look red and poofy after having worn it all night.

  • The gums feel uncomfortable when you have it on.

This condition will require a night guard adjustment by shorting or relieving the areas that are problematic. This appointment should take about 10-15 minutes in total for your dentist.

How to fix poor fitting night guard

If your night guard is not fitting the way it should be, you should have it adjusted or remade. Those are the only two solutions for a bad fitting mouth guard.

Below is a table listing all of the ways it could fit poorly and how to fix it.

Night guard symptom


Can't close mouth

Bite adjustment

Feels tight

Relieve interior of night guard

Feels loose

New night guard

Only a few teeth are touching

Bite adjustment

Won't fit over teeth

New night guard

Gum pinching

Shorten night guard


Most of the issues with a bad fitting night guard can be adjusted but it requires a visit to your dentist. Your dentist can shorten, relieve, and equilibrate the oral appliance to make it fit better. This is a customization process that is typically performed after you've worn the appliance for a couple of days.

How a night guard is adjusted:

  1. Identify the areas that need adjustment.

  2. Remove, reduce, or relieve those areas with an acrylic burn.

  3. Polish off adjusted spots.

The adjustment procedure is simple because it only takes a couple of seconds. However, the appointments often take longer than that because most patients have trouble communicating where exactly the problematic areas are that need to be adjusted.


If the night guard cannot be adjusted, the only solution left would be to have it remade. Essentially your dentist will retake the molds of your teeth and send it back to the lab to have them make a brand new one.

Reasons why it didn't fit in the first place:

  • You stopped wearing it and your teeth shifted.

  • The teeth impressions were distorted during transportation.

  • Laboratory error where it was made suboptimally.

Can I fix it at home?

Unfortunately there is no home remedy for a night guard that doesn't fit well. You are unable to adjust it or make your own at home.

All adjustments and remakes need to be done with a dentist. You simply do not have the same equipment and instruments that they have to do this procedure.

There is no reason for you to shy away from an adjustment because the follow up visits are usually covered.


Even if your night guard fits well, it may feel foreign at first since it is a sizable appliance in your mouth. However, it shouldn't be painful or uncomfortable. The good news is that it should become more and more comfortable over time as you get into the habit of wearing it.

Although if your night guard does not fit as it should, there will be a couple of tell-tale signs. If you are experiencing any of these, you should reach out to your dentist to have it evaluated. Most of the issues can be easily adjusted with a 10-15 minute appointment but the more severe ones will need a full remake of the mouth guard.

There is no reason why you should live with and continue using an improper fitted one. So what are you waiting for? Go schedule an appointment with your dentist because you definitely can't adjust it yourself at home.



David Chen 200 x 200.jpg

About the author: Dr David Chen, DDS

Hello, I'm Dr Chen and I'm an actively practicing dentist in Long Island City, NY. I graduated from Columbia University College of Dental Medicine in 2016 but prior to going to dental school I was already working in the dental field. It's been more than a decade since I first got to know dentistry and let me tell you, time flies by quickly. Since then I've developed a fondness for writing, which is how this all got started!

Association Memberships:

Medical Disclaimer:

This blog is purely meant for information purposes and should not be used as medical advice. Each situation in your mouth is unique and complex. It is not possible to give advice nor diagnose any oral conditions based on text nor virtual consultations. The best thing to do is to go in person to see your dentist for an examination and consultation so that you can receive the best care possible.

The purpose of all of this oral health information is to encourage you to see your dentist and to inform you of what you may expect during your visit. Due to the unfortunate nature of dentistry, there isn't really any true home remedies that will get rid of dental problems. Roughly 99.99% of them require in-person intervention by a healthcare professional.

Hint: That is the reason why you can't eliminate seeing dentists in your life!

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