Cheek biting, medically known as buccal mucosa biting, refers to the act of involuntarily or habitually chewing the tissue lining the inside of the mouth. This behavior exists on a spectrum, ranging from a common, accidental occurrence to a chronic, repetitive action. Understanding the triggers is the first step toward addressing it, as it can signal both physical misalignment and underlying behavioral patterns. The distinction between an isolated incident and a persistent habit directs the search for the root cause and appropriate management.
Accidental and Anatomical Causes
The most common cause of cheek biting is purely mechanical, often linked to the structure and alignment of the teeth. This type of biting is usually unintentional, occurring suddenly during routine actions like chewing food or speaking quickly. A significant physical cause is malocclusion, which describes any improper alignment of the teeth or the way the upper and lower jaws meet. When the teeth do not close together correctly, the soft tissue of the cheek can be caught between the chewing surfaces, leading to trauma.
Specific types of misalignment, such as a narrow dental arch or protruding teeth, can decrease the necessary protective space for the cheek tissue. The problem also arises from dental interventions that temporarily alter the mouth’s landscape. Ill-fitting or new dental appliances, including dentures, retainers, crowns, or fillings, can create an irregular surface or change the bite position, increasing the likelihood of the cheek being trapped.
A temporary form of accidental biting is iatrogenic trauma, which happens following a dental procedure involving a local anesthetic. While the nerve block is active, the patient cannot feel the cheek tissue, making it susceptible to being chewed on without awareness. This type of biting is transient and ceases once the anesthetic wears off. These anatomical factors indicate a need for dental correction rather than a behavioral intervention.
Habitual and Stress-Related Behaviors
When cheek biting becomes a chronic, repetitive, and often unconscious pattern, it is clinically referred to as Morsicatio Buccarum. This condition is classified as a Body-Focused Repetitive Behavior (BFRB), placing it in the same category as other self-grooming actions like nail-biting or hair-pulling. These behaviors are typically not a sign of self-harm but rather a coping mechanism that helps manage emotional states.
The biting is frequently triggered by feelings of stress, anxiety, boredom, or intense concentration, serving as a way to self-soothe or release internal tension. The behavior often occurs automatically and without conscious awareness, particularly when they are engaged in another activity or in a “trance-like” state.
Over time, a vicious cycle can develop where the repetitive biting creates an irregular patch of tissue inside the cheek. This rough or uneven surface creates a perceived imperfection, which compels the individual to bite or chew the area further to “smooth” it out. This compulsion reinforces the habit, making the behavior difficult to stop despite the resulting pain or injury. Chronic cheek chewing is linked to psychological regulation and is more common in individuals experiencing emotional distress.
Immediate Physical Consequences
The immediate result of repeated cheek biting is physical damage to the oral mucosa, the delicate lining of the mouth. The initial trauma often presents as painful lesions or ulcers, which are open sores caused by the tissue being repeatedly crushed or torn. These open areas are susceptible to irritation from spicy or acidic foods, causing stinging sensations and discomfort during chewing or speaking.
If the habit continues, the body attempts to protect the injured area by causing the tissue to thicken, a process called hyperkeratinization. This results in the formation of white, rough, or shredded patches on the inner cheek, typically along the occlusal plane where the teeth meet. Although this thickening is a defensive response, the resulting rough texture can increase the urge to chew, perpetuating the cycle of injury.
In severe or long-standing cases, the constant presence of open sores and inflammation raises the risk of a secondary bacterial infection. While chronic cheek biting is considered a benign condition that does not increase the risk of oral cancer, the persistent tissue damage can lead to chronic inflammation and scarring.
When to Seek Professional Guidance
Deciding when to seek help depends on determining whether the cause is anatomical, behavioral, or a combination of both. A dental consultation is the appropriate starting point if the biting is a new issue related to recent dental work or happens frequently during mealtimes. A dentist can evaluate the bite alignment (malocclusion) and check for sharp or misaligned dental restorations causing accidental trauma. They may recommend orthodontic adjustments or the use of a custom-fitted mouthguard to shield the tissue from the teeth.
If the habit is chronic, occurs unconsciously, or is clearly linked to emotional triggers like stress or anxiety, a behavioral health professional should be consulted. Therapists specializing in Body-Focused Repetitive Behaviors (BFRBs) can employ techniques like habit reversal training. This training helps the individual become aware of the behavior and substitute it with a less harmful action. Immediate professional attention is warranted if red flags appear, such as persistent bleeding, signs of infection like pus or swelling, or lesions that do not heal despite conscious efforts to stop the habit.