A mouth guard is a removable device that fits over your teeth to protect them from physical damage, whether that’s a hit to the face during sports, the grinding and clenching you do in your sleep, or the airway collapse that causes snoring and sleep apnea. Most people associate mouth guards with athletics, but they serve three distinct purposes depending on the type you use.
Protection During Sports
The most familiar use of a mouth guard is preventing dental injuries during contact sports. An athlete who doesn’t wear one is roughly 60 times more likely to damage their teeth compared to someone who does. Sports like football, hockey, basketball, boxing, wrestling, and soccer all carry a high risk of chipped, cracked, or completely knocked-out teeth from collisions, falls, or stray elbows.
A sports mouth guard works by absorbing and redistributing the force of an impact across a broader area, rather than letting it concentrate on a single tooth. This protects not just the teeth themselves but also the lips, gums, and surrounding soft tissue. The guard acts as a cushion between the upper and lower teeth, which also reduces the chance of biting your tongue or cheek during a hit.
Preventing Damage From Teeth Grinding
If you grind or clench your teeth, especially at night, a mouth guard (often called a night guard or occlusal guard) keeps your upper and lower teeth from making direct contact. The forces generated during nighttime grinding are significant. Over time, that tooth-on-tooth pressure leads to worn enamel, cracks, fractures, and can even accelerate bone loss in people with gum disease.
Night guards are considered the first line of treatment for clenching and grinding. They cushion the force and create a barrier that prevents the surfaces of your teeth from wearing each other down. A specific version called a stabilization splint goes a step further: it’s made of hard resin and adjusted to mimic a healthy bite, which helps balance the relationship between your jaw joint, teeth, and the muscles that control chewing. This is particularly useful for people with TMJ disorders, where the jaw joint becomes overloaded or misaligned. A properly fitted guard doesn’t just protect the teeth; it reduces strain on the muscles around the jaw and decreases the load on the joint itself.
Treating Snoring and Sleep Apnea
A third category of mouth guard is designed to keep your airway open while you sleep. These are called mandibular advancement devices, and they work by pushing your lower jaw slightly forward and downward. That forward shift does several things at once: it pulls the base of the tongue away from the back of the throat, moves the fatty tissue around the airway to the sides, and stiffens the walls of the throat so they’re less likely to collapse inward.
The result is a wider, more stable airway, particularly in the area behind the soft palate where obstruction most commonly occurs. This reduces or eliminates the vibration that causes snoring and prevents the repeated airway closures that define obstructive sleep apnea. These devices are custom-made by a dentist and are typically used for mild to moderate sleep apnea, or for people who can’t tolerate a CPAP machine.
Three Types of Mouth Guards
Regardless of their purpose, mouth guards come in three basic designs, and the differences in fit and protection are substantial.
- Stock (prefabricated): These come in preset sizes and can’t be adjusted. They’re the cheapest option but offer the least protection and are often uncomfortable because they don’t conform to your teeth. They’re generally considered the least desirable choice.
- Boil-and-bite: The most popular option among athletes. You soften these in hot water and then bite into them so they mold roughly to your dental arch. They fit better than stock guards, but the molding process can make them thinner in some areas, reducing protection where it matters most.
- Custom-made: Fabricated by a dentist using a mold or digital scan of your teeth. These fit the exact contours of your mouth, which makes them more comfortable, easier to breathe and talk with, and significantly better at protecting both hard and soft tissue. Custom guards are made from more durable materials and typically last three to five years with proper care, while store-bought versions wear out much faster.
For high-impact sports or serious grinding, custom-made guards are the clear winner. The precise fit means they stay in place, don’t cause irritation, and provide consistent coverage across the entire dental arch.
How to Care for a Mouth Guard
Bacteria build up quickly on a mouth guard that isn’t cleaned regularly, leading to bad breath and potential infections. Before putting it in, brush and floss your teeth. When you take it out, rinse it in cool water and clean it with a soft-bristle toothbrush using nonabrasive toothpaste, antibacterial soap, or alcohol-free mouthwash. Keep a separate toothbrush just for this to avoid transferring bacteria. Let the guard dry completely before storing it, since leftover moisture promotes bacterial growth.
Store it in a ventilated, hard-sided container so air can circulate. Keep it away from hot water, direct sunlight, and high temperatures, all of which can warp the material and ruin the fit. Once a month, do a deeper clean with a denture cleaning tablet or a solution of vinegar and hydrogen peroxide.
When to Replace Your Mouth Guard
Even a well-maintained mouth guard has a limited lifespan. Most dentists recommend replacing yours every 6 to 12 months, particularly if you’re an athlete or a heavy grinder. Watch for cracks, tears, thinning, or any loss of shape. A guard that feels loose or causes new irritation to your gums or cheeks has likely warped beyond usefulness. You should also replace it after a significant illness, since bacteria can linger on the surface, and after any notable change in weight, which can subtly alter the shape of your mouth and affect the fit.