Nocturnal cheek biting, formally known as morsicatio buccarum, is a common problem that causes painful sores and inflamed tissue inside the mouth. This involuntary habit happens while you sleep, often leaving you to discover the damage the following morning. Understanding the root causes of this subconscious action is the first step toward relief. This issue is often related to underlying physiological factors that disrupt the natural resting state of the jaw and mouth during sleep.
Why Nocturnal Cheek Biting Occurs
The primary cause of nighttime cheek biting is linked to an involuntary tightening and movement of the jaw muscles known as sleep bruxism. This unconscious clenching or grinding generates significant force, causing the teeth to forcefully trap the soft tissue of the cheek against the biting surfaces. Episodes of bruxism are frequently triggered by increased psychological stress and anxiety, which cause muscle tension in the jaw to manifest during sleep.
Dental alignment plays another role in the mechanics of nocturnal biting. When the upper and lower teeth do not meet in a balanced way, known as malocclusion, the inner cheek lining is more easily caught between the teeth. This is exacerbated by sharp edges, such as those from a chipped tooth, a poorly contoured filling, or erupting wisdom teeth, which can repeatedly snag the cheek tissue.
The jaw’s position during sleep is also influenced by muscle tension. Stress hormones contribute to a heightened state of muscle activity, preventing the jaw from fully relaxing. In some cases, the body’s involuntary response to a partially blocked airway during sleep can cause the jaw to move forward in a reflex action, which may inadvertently lead to the cheek being bitten.
Practical Steps for Immediate Relief
One accessible and immediate solution involves the temporary use of an over-the-counter mouthguard. These boil-and-bite devices soften in hot water, allowing you to create a semi-custom impression of your teeth. While they do not address the underlying cause, these guards create a cushioning barrier that prevents direct tooth-on-cheek contact, allowing existing sores to heal.
Implementing a nightly routine focused on jaw relaxation is an effective behavioral step. Before bed, apply a warm compress to the jaw area, specifically over the masseter muscles, for about ten minutes to encourage muscle détente. Follow this with gentle jaw stretches, such as slowly dropping the jaw open and holding for a few seconds, or performing a light, circular massage on the muscles near the ear.
Dietary adjustments can support muscle relaxation by reducing factors that contribute to jaw tension. Limiting the intake of stimulants like caffeine, alcohol, and nicotine late in the day is recommended, as these substances can increase muscle activity and disrupt restorative sleep. Furthermore, focusing on a diet rich in magnesium—a mineral known for its muscle-relaxing properties—may help decrease the frequency of clenching episodes.
Consulting a Specialist for Long-Term Solutions
For chronic or severe cases, professional intervention from a dental specialist is necessary for a long-term solution. A dentist can provide a custom-fitted night guard, fabricated from a precise mold of your teeth and often made of durable acrylic material. Unlike generic guards, this appliance is designed to perfectly align your bite and is less bulky, offering superior comfort and protection against bruxism forces.
The dentist can also perform minor dental procedures, such as smoothing down a sharp cusp or edge on a tooth that is repeatedly causing trauma to the cheek, a process called selective grinding. If the biting is related to significant misalignment, an orthodontic assessment may be necessary. Severe malocclusions often require corrective treatment with braces or clear aligners to permanently adjust the jaw relationship and eliminate the cheek-trapping mechanism.
If bruxism is suspected to be a reflex action, a referral to a sleep specialist is appropriate to investigate a connection to Obstructive Sleep Apnea (OSA). Bruxism is frequently correlated with OSA, as the jaw movement can be an unconscious attempt to move the lower jaw forward to open a blocked airway. If other treatments fail to manage severe muscle activity, a physician may suggest targeted injections of botulinum toxin A (Botox) into the masseter and temporalis muscles to temporarily reduce the muscle’s ability to clench.