Snoring mouthpiece side effects: what's normal and when to stop

What’s going on

A jaw-advancing mouthpiece holds your lower jaw forward for hours every night. Your teeth, gums, jaw muscles and jaw joints take that load. Most side effects come from there.

The FDA tells makers of these devices to warn about five things:

• Tooth movement or changes in how your teeth meet.
• Sore gums or teeth.
• Pain or soreness in the jaw joint.
• Blocked mouth breathing.
• Extra saliva.

The AASM and AADSM guideline adds dry mouth and trouble chewing in the morning. It notes that most side effects are dental. It also found that side effects make people quit oral appliances less often than they make people quit CPAP.

Short-term side effects

These tend to show up in the first nights and weeks. Cleveland Clinic lists them as the short-term group, and says getting used to an appliance takes about two to four weeks.

• Drooling. Your mouth makes more saliva with something in it. This often eases as you get used to it.
• Dry mouth. Some people get the opposite.
• Sore teeth or gums. The trays press on your teeth. Mild pressure is expected; sharp pain in one tooth isn’t.
• Sore jaw muscles or joint. Your jaw is held in a new position for hours.
• Morning bite feels off. When you take the mouthpiece out, your back teeth may not meet quite as usual. Chewing can feel odd for a while.

Long-term side effects

These build slowly, over months to years of nightly wear. Cleveland Clinic lists bite changes, tooth movement or loose teeth, and changes in the jaw muscles or joint.

A 2025 review pooled 23 studies of people who used oral appliances for six months or longer. On average, the upper front teeth tipped back and the lower front teeth tipped forward. The overlap between the upper and lower front teeth shrank by just under 1 mm, and kept shrinking over the years.

The jawbones themselves didn’t change much. The guideline also cites a two-year study with similar small shifts. The changes are small on average, but they add up with years of use.

Most of this research is on custom appliances used for sleep apnea. There’s much less on store-bought mouthpieces worn for snoring. It’s reasonable to assume the same forces act on your teeth either way.

What helps

Morning bite resetters and jaw exercises

Some dentists give a small morning device, sometimes called a morning repositioner or occlusal guide. You bite into it after taking the mouthpiece out, to help guide your jaw back to its usual position. Some pair it with jaw exercises.

The evidence is mixed:

• In a small trial of people with jaw joint problems using a mouthpiece for sleep apnea, jaw exercises reduced pain. Those people also wore their mouthpiece more.
• In a 2026 study, people used jaw exercises and a morning guide for a year. They still lost some contact between their back teeth.

So exercises may make wearing a mouthpiece more comfortable. They may not prevent slow bite changes. The guideline says more research is needed.

Everyday steps

1. Start small. If your mouthpiece is adjustable, begin at the lowest setting and move forward one step at a time only if you still snore.
2. Give it time. Mild drooling and soreness often settle over the first few weeks.
3. Keep it clean and fitted. Clean it the way the maker directs. Replace it if it cracks or no longer grips your teeth.
4. Mind your nose. A mouthpiece can make mouth breathing harder. If your nose is often blocked, deal with that first.

When to stop and see a dentist

Take the mouthpiece out and see a dentist if you notice:

• Pain in one tooth, or a tooth that feels loose.
• Jaw pain that lasts through the day, or a jaw that clicks, locks or won’t open fully.
• A bite that still feels wrong hours after you take it out, or that feels different week to week.
• Gums that bleed, swell or get sore where the trays sit.

The FDA lists loose teeth and advanced gum disease as reasons not to use these devices at all.

Skip a mouthpiece altogether if you’re under 18 or have central sleep apnea. The same goes for loose teeth, gum disease, dentures, braces, jaw joint problems, or recent implants or major dental work. The who shouldn’t use a snoring mouthpiece page explains each.

If you also grind your teeth, jaw and tooth soreness can come from the grinding itself. Toothache.com explains jaw and tooth pain from grinding, and teeth grinding and snoring covers how the two connect.

What a dentist or doctor can do

A dentist can check your teeth, gums and jaw joints, and look at how your bite has changed. They can tell you whether it’s safe to keep going, and whether a different design or a custom appliance would suit you better.

The guideline suggests regular dentist follow-up for people using oral appliances for sleep apnea, to watch for bite changes and reduce them. Store-bought mouthpieces come with no follow-up, so booking a check yourself makes sense.

If you’re still snoring despite the mouthpiece, or you feel tired in the day, see a physician. The guideline notes that snoring often comes with sleep apnea.

For how the options compare, see over-the-counter vs custom.