If you often wake up with a headache or pain in your jaw area, chances are you grind or clench your teeth at night, something known as sleep bruxism. This can damage your pearly whites over time, warns Sharon Huang, DDS, general and cosmetic dentist at Les Belles NYC in Manhattan, but a night guard can help.

A night guard is an appliance that fits over your teeth, to protect them from the effects of bruxism, Dr. Huang tells LIVESTRONG.com. "It works like a shock absorber to help take the pressure off teeth, so there's less force from the muscle and joints to help prevent breaking or cracking teeth, chipping teeth, gum recession, breaking fillings and muscle tension."

For the best customized fit and highest quality materials, you'll need a prescription night guard from your dentist. But if that's not in the budget right now or you're in between dental visits, an over-the-counter option can work, too.

Because there are plenty of over-the-counter night guards to choose from, it can be hard to know which is best for you. Here, we've narrowed it down to the five best night guards based on the recommendations of Dr. Huang as well as Manhattan-based dentist Steven Davidowitz, DDS; Rhonda Kalasho, DDS, dentist and founder of TruGLO Modern Dental in Los Angeles; Richard Marques, BDS, cosmetic dentist in London and Tina Saw, DDS, general and cosmetic dentist at Elevated Smiles in Carlsbad, California, and founder and CEO of Oral Genome.

The Best Night Guards for Teeth Grinding and Clenching

When it comes to night guards, this is as good as it gets without going to the dentist, Dr. Huang says. With four different night guard options to choose from, including hard, soft, dual layer and daytime hard, each with their own customizable fit, it's easy to see why this night guard has such rave reviews (4.7 out of 5 stars on Amazon).

Each purchase comes with two impression kits, each with two small trays for the upper and lower teeth. This way, you have a backup kit in case your first attempt is unsuccessful.

Once you're done making your impression, you send it into enCore using the prepaid label that arrived with your purchase, and within two weeks, your custom night guard is sent to you in the mail.

All materials are BPA- and latex-free and made without harmful chemicals.

​​Buy it:​​ enCoreGuards.com; ​​​Price:​​​ $129 for dual layer laminate (hybrid) guard

This over-the-counter night guard uses a "boil-and-bite" process.. Though this doesn't provide a true custom fit, it offers a semi-custom fit that can help cut down on nighttime bruxism, notes Dr. Davidowitz.

These guards are also less than $20, which is quite a steal compared to the $300 to $400 you would likely pay if you purchased a customized guard from your dentist's office (although you'll have to replace them more often).

Made from BPA- and latex-free material, all you have to do to create a semi-custom fit is microwave and warm the trays, place them in your mouth and mold them over your teeth for three minutes. They have a nice minty flavor that most people don't mind and can last up to six months.

​​Buy it:​​ ​Amazon.com; ​​​Price:​​​ $19

If you're OK not having a custom fit of any kind, this night guard can be quite useful to cut down on teeth grinding. These are one-size-fits-all, which means you don't have to worry about boiling, cutting or molding them to your teeth, which some people may consider to be a pesky process.

These can be worn on the upper or lower teeth, and — arguably the best part — they are disposable. They come in packs of 10 and 16 and can be used for up to three nights, so a single package can last you a month to a month and a half. They also come individually packaged, so they're great for travel — and you don't have to worry about packing them on your return trip.

"They are a quick over-the-counter solution for grinders and clenchers," Dr. Saw says.

​​Buy it:​​ ​Amazon.com; ​​​Price:​​​ $4.49 for 16

Thanks to a patented wedge design, this night guard helps lower your lower jaw and slide it forward in an effort to help prevent grinding and teeth clenching. This helps ensure you wake up with significantly less soreness and protects your teeth while you sleep.

To create your custom fit, you boil the Ora-GUARD in water for 90 seconds, transfer it to cold water for no more than 1 second and then carefully place it on your lower teeth. After biting down gently, you slide the guard and press it against your teeth to create a perfect fit.

Unlike most at-home night guards, this one comes with a 1-year warranty that's good from the date of purchase.

​​Buy it:​​ ​Walmart.com; ​​​Price:​​​ $29

If you think your teeth grinding may be related to some sort of sleep disorder, you may be right—and, in this case, a customizable night guard like this one from SnoreRx may be more suitable for your needs.

This mouth guard is specifically designed to cut down on bruxism that may be related to sleep conditions such as snoring and sleep apnea. Unlike many other night guards on the market, this one comes with both a top and bottom tray to double down on the protection and keep your jaw placed in the right position to not only prevent grinding but also keep your airway open to cut down on snoring.

It utilizes boil-and-bite technology, but you also have the option to adjust it by up to six millimeters to create an even more customized fit.

​​Buy it:​​ ​Walgreens.com; ​​​Price:​​​ $60

Before you shop for the right night guard to give your teeth and mouth relief, here are some important factors to keep in mind:

Guards often fall into one of three categories: soft, hard and dual laminated.

A good night guard needs to be precisely fitted for your unique mouth. Not only is this important in terms of comfort, but a poorly fitting night guardd can actually make clenching worse, or make you develop symptoms associated with temporomandibular joint dysfunction, also known as TMJ, and a misaligned jaw, notes Dr. Kalasho. She also recommends that a night guard fit very snugly so it doesn't fall out during sleep.

The best night guards are made out of clear acrylic plastic, as these are more adaptable to shape and can provide a more customized fit, notes Dr. Kalasho.

However, she also points out that your night guard should be BPA-free. BPA stands for Bisphenol A, a chemical that has been linked to myriad health conditions, including cancer, per the National Institute of Environmental Health Sciences.

A night guard shouldn't be too tight or uncomfortable in any way, notes Dr. Huang. "Don't try to force a night guard on your teeth if it doesn't fit," she says. "A night guard should easily pop onto the teeth, not have any rough edges and should feel smooth to the tongue when you rub your tongue against it when on the teeth."

The night guards that you get from your dentist may last up to three years, Dr. Huang says. However, the at-home versions tend to last between three and six months. (Night guards made from harder materials will typically last longer than softer guards.)

Night guards range in price for a reason. If you're buying one from your dentist, you're likely getting the most customization possible, as well as high-quality materials. But you can get a great night guard over the counter at a significantly lower price. Most nonprescription night guards range between $17 and $60.

If you have discomfort from teeth grinding or jaw pain, Dr. Davidowitz recommends making an appointment to see your dentist so your teeth, bite and jaw can be evaluated.

Also, once you start using a night guard, make sure to bring it with you to your dental checkups (every six months) to make sure the guard is working well.

If, on the other hand, you notice that your jaw clicking or pain resolves over time as you're using your night guard, Dr. Marques recommends asking your dentist whether you can stop wearing your night guard. "Sometimes you may still need to continue, but you may also be able to wear the guard occasionally and during times when you grind more," he says.