Oral Appliance Side Effects

Jaw soreness is the most common side effect of oral appliance therapy, particularly during the first few days to weeks of use. The appliance holds the lower jaw in a slightly forward position, which engages muscles that are not accustomed to this position during sleep.

This soreness is typically mild — similar to the feeling after holding your mouth open for a long dental appointment — and usually resolves as the jaw muscles adapt. If soreness persists or is severe, your dental provider can:

• Reduce the degree of jaw advancement temporarily and gradually increase it over time
• Adjust the appliance fit to reduce pressure on specific areas
• Recommend jaw exercises to improve flexibility and reduce discomfort
• Evaluate whether the appliance type is the best fit for your anatomy

Some patients notice that their teeth do not fit together quite the same way in the morning, particularly when first starting treatment. This occurs because the jaw has been held forward all night and needs time to settle back into its natural resting position.

This morning bite change is usually temporary and resolves within minutes to an hour after removing the appliance. Your dental provider may recommend morning exercises — such as gently biting on a flexible mouthguard — to help the jaw realign.

In some cases, minor long-term bite changes can develop over months or years of use. Regular monitoring by a dental provider helps identify any developing changes early. If significant bite changes occur, the provider can adjust the appliance or recommend management strategies.

Some patients experience dry mouth when using an oral appliance. This can occur because the appliance may encourage mouth breathing or may slightly reduce saliva flow during sleep. Dry mouth is generally manageable through several strategies:

• Drinking water before bed and keeping water nearby at night
• Using a room humidifier to add moisture to the air
• Discussing with your provider whether an appliance adjustment can reduce mouth breathing
• Using saliva substitutes or oral moisturizing products if needed
• Maintaining good nasal breathing — treating nasal congestion if present

Excess saliva is a common temporary side effect when first starting oral appliance therapy. The mouth detects the appliance as a foreign object and increases saliva production as a response. This is the body's natural reaction and typically resolves within a few days to weeks as the mouth adapts.

If excess saliva persists beyond the initial adjustment period, your dental provider can check the appliance fit and make any needed adjustments. Most patients find this side effect resolves on its own without intervention.

During the initial weeks of oral appliance therapy, various temporary sensations are normal as the mouth, jaw, and teeth adapt to wearing the device. These may include:

• Mild pressure on the teeth, particularly in the morning
• Sensation of the jaw being slightly forward upon waking
• Temporary difficulty finding a comfortable jaw position when the appliance is first inserted
• Awareness of the appliance in the mouth during sleep onset

These sensations typically diminish as adaptation occurs. Consistent nightly use helps the mouth adapt more quickly than intermittent use.

Because an oral appliance holds the jaw in a forward position, some patients may experience TMJ-related symptoms, particularly during the early adjustment period. These may include:

• Jaw joint clicking, popping, or grinding sounds
• Discomfort or tenderness in the jaw joint area
• Difficulty or discomfort when opening the mouth wide
• Muscle fatigue in the jaw, face, or neck

Patients with a history of TMJ disorders may be at higher risk. Your dental provider evaluates jaw joint function during the initial examination and monitors it throughout treatment. If TMJ symptoms develop or worsen, the provider may reduce advancement, adjust the appliance, or recommend further evaluation. Learn more in our TMJ treatment guide.

The appliance contacts the gums and oral soft tissues, which can cause irritation in some patients. This may appear as:

• Mild gum tenderness where the appliance edges rest
• Soft-tissue soreness from appliance contact
• Minor irritation from a device edge that does not fit precisely

Most gum irritation can be addressed by adjusting the appliance's fit or smoothing an edge. If you notice persistent gum irritation, contact your provider rather than continuing to wear a device that causes discomfort. Good oral hygiene and regular dental check-ups help maintain healthy gums during treatment.

One of the more significant potential long-term effects of oral appliance therapy is gradual tooth movement or changes in the bite (occlusion). Over months or years of nightly use, the forces applied by the appliance can subtly shift tooth positions or alter how the teeth meet.

Not all dental changes are temporary. While morning bite sensations are usually short-lived, some patients develop minor long-term occlusal changes that do not fully resolve on their own. Regular monitoring by a dental provider helps identify these changes early so adjustments can be made. In some cases, the provider may recommend management strategies such as morning exercises, appliance modifications, or dental interventions.

This does not mean oral appliance therapy is unsafe — it means that long-term monitoring is part of responsible treatment. The follow-up and verification guide explains how ongoing dental and bite monitoring works.

Over time, an appliance may fit less securely as dental anatomy changes, materials age, or minor tooth movement occurs. Signs of a retention concern include:

• The appliance feels looser than when it was first delivered
• The device dislodges during sleep
• Teeth feel different when the appliance is inserted
• The appliance no longer sits evenly on the teeth

Changes in fit can affect both comfort and effectiveness. If you notice retention concerns, contact your provider — the appliance may need adjustment, reline, or replacement. Learn about the fitting and adjustment process in our fitting and titration guide.

While many side effects — such as initial jaw soreness and excess salivation — are temporary and resolve as the mouth adapts, some effects may persist or develop over time. It is important to understand that:

• Minor long-term bite or occlusal changes can occur with prolonged use and may not fully resolve without intervention
• TMJ symptoms may persist in some patients, particularly those with pre-existing jaw joint issues
• Tooth movement, if it occurs, may require dental management
• Dry mouth may be an ongoing issue for some patients rather than a temporary one

This does not mean you should avoid oral appliance therapy — it means that regular professional follow-up is essential. Early identification of side effects allows your provider to make adjustments that may prevent or minimize long-term changes. Do not assume that persistent symptoms will always disappear on their own.

Regular follow-up appointments with your dental sleep medicine provider are essential for managing side effects and ensuring treatment success. During these visits, the provider can:

• Assess how well the appliance is fitting and functioning
• Make precise adjustments to improve comfort and effectiveness
• Gradually advance the jaw position if needed for optimal airway opening
• Monitor dental health, bite alignment, and jaw joint function
• Address any side effects that have developed since the last visit
• Evaluate treatment effectiveness and recommend follow-up sleep testing if needed

The adjustment period typically involves more frequent visits (every 1–2 weeks initially), transitioning to regular check-ups (every 6–12 months) once the treatment is well-established. If you experience side effects that concern you between appointments, contact your provider rather than discontinuing use. Learn more about the full treatment process in our oral appliance therapy guide.