Tongue chewing involves the repetitive biting or sucking of the tongue. While an accidental bite during a meal is momentary, chronic tongue chewing is a distinct, often subconscious, behavior that causes persistent injury and discomfort. This behavior is formally classified as a body-focused repetitive behavior (BFRB) when habitual, but it can also be a symptom of underlying physical or neurological issues. Understanding the root cause of this repetitive action is the first step toward effective management and preventing long-term oral health complications.
Mechanical and Dental Contributors
Physical misalignment within the mouth is a direct cause of repeated tongue injury, making the tongue an easy target for the teeth. A condition known as malocclusion, where the upper and lower teeth do not align properly when the mouth is closed, can create an environment where the tongue is constantly trapped between the chewing surfaces. This structural issue means that even normal jaw movements, such as those during speech or swallowing, can accidentally result in a painful bite.
Sharp or irregular surfaces on the teeth can also repeatedly snag and injure the tongue tissue. These jagged edges often result from chipped teeth, worn-down fillings, or poorly contoured dental restorations. If the tongue repeatedly makes contact with such an abrasive surface, it can develop a sore spot that the tongue naturally seeks out. Furthermore, ill-fitting dental appliances, like retainers or dentures, can shift the jaw’s position or create an unnatural space where the tongue inadvertently rests and is susceptible to biting.
Stress, Anxiety, and Behavioral Habits
For many individuals, tongue chewing is a manifestation of an oral parafunctional habit, which involves using the mouth for activities outside of normal functions like eating or speaking. This activity is frequently triggered or amplified by psychological states, particularly heightened levels of stress, anxiety, or boredom. The repetitive action provides a form of sensory stimulation or a coping mechanism, serving as a physical outlet for pent-up tension or emotional discomfort. Individuals may find themselves engaging in the behavior unconsciously while concentrating intensely or during moments of inactivity.
The behavior can quickly become self-reinforcing, creating a cycle that is challenging to break. After an initial injury, the resulting rough spot or inflammation on the tongue attracts the person’s attention, prompting them to repeatedly examine the area with their teeth. Identifying the specific emotional or environmental triggers is a primary step in behavioral management, as the habit often serves as an automatic diversion from internal feelings. Increasing awareness of when and why the chewing occurs is often the first step toward gaining control.
Involuntary Movements During Sleep
When tongue chewing occurs primarily at night, the cause is often an involuntary movement disorder that happens during sleep. Sleep bruxism, characterized by the clenching and grinding of teeth, is a common culprit where the tongue gets accidentally caught between the jaw muscles. This nocturnal activity is typically related to sleep arousal and can result in bite marks along the sides of the tongue, where the teeth meet.
More forceful and focused tongue biting can sometimes be a sign of a neurological event occurring during sleep. Nocturnal seizures, particularly generalized tonic-clonic seizures, involve uncontrolled muscle contractions that can forcefully drive the jaw shut. A classic sign differentiating a seizure-related tongue injury is a bite mark located on the lateral (side) aspect of the tongue. This is in contrast to the tip, which is more commonly injured during daytime accidents or simple bruxism.
When to Consult a Professional and Management
Consulting a healthcare professional is advisable when tongue chewing is persistent, causes significant pain, or leads to chronic tissue damage. A dentist should be the first point of contact if the problem appears related to malocclusion, sharp tooth edges, or ill-fitting appliances. They can correct structural issues or prescribe a custom-fitted mouthguard, which creates a physical barrier to protect the tongue during both daytime clenching and nocturnal bruxism episodes.
If the behavior is driven by stress or anxiety, a mental health professional specializing in body-focused repetitive behaviors may recommend cognitive behavioral therapy (CBT) or habit reversal training (HRT). These techniques focus on helping the individual identify triggers and substitute the tongue chewing with a less destructive, competing response, such as gently clenching a fist.
Immediate medical attention is necessary if the tongue biting is accompanied by red flag symptoms, which may indicate a need for neurological evaluation to rule out a seizure disorder. These symptoms include:
- Unexplained confusion.
- Loss of consciousness.
- Repeated biting of the lateral tongue.
- Signs of infection (such as persistent swelling, pus, or fever).