Tongue chewing is an oral activity that falls outside the normal functions of speaking, swallowing, or eating. This behavior involves the repetitive, rhythmic contact of the tongue against the teeth or other oral tissues. It is medically classified as a parafunctional habit, meaning an atypical use of the oral system. While occasional tongue biting is common, chronic tongue chewing is a pattern that can be either an involuntary movement or a learned, stress-related habit.
Defining Tongue Chewing Behavior
Chronic tongue chewing is often referred to as morsicatio linguarum, meaning “chewing of the tongue.” This behavior is characterized by repeated, excessive pressure or gnawing of the tongue, most often along its lateral borders. The resulting physical manifestation is typically a white, thickened, and sometimes frayed appearance on the sides of the tongue tissue.
When the behavior is a non-conscious, repetitive action, it is categorized as a Body-Focused Repetitive Behavior (BFRB), similar to nail-biting or hair-pulling. The action often provides sensory stimulation or functions as a coping mechanism during anxiety or boredom. A more serious presentation involves involuntary, uncontrolled movements that are neurological in origin, falling under the umbrella of orofacial dyskinesia. These movements are distinct because they cannot be stopped consciously, differentiating them from habitual parafunctional activity.
Identifying the Underlying Causes
The reasons a person develops chronic tongue chewing can be broadly grouped into psychological, neurological, and pharmaceutical categories. Psychological factors are perhaps the most common, where the repetitive action serves as a self-soothing mechanism. High levels of stress, chronic anxiety, or tension can trigger the behavior, leading the individual to chew the tongue to cope with heightened emotional states.
The cause may also be rooted in neurological function, where the movement is an involuntary motor symptom rather than a habit. Certain neurological conditions, including Tourette’s syndrome or conditions related to motor control, can manifest as orofacial dyskinesia, involving uncontrollable tongue and jaw movements. A misaligned bite, or malocclusion, can also predispose an individual to the habit by placing the tongue in a vulnerable position against the teeth, making accidental biting more likely to become a chronic issue.
A specific cause is the side effect of certain medications, which can induce a movement disorder called Tardive Dyskinesia (TD). Antipsychotic drugs, and less commonly, some antidepressants or anti-nausea medications, can alter brain chemistry, leading to involuntary, repetitive movements of the face, jaw, and tongue. These drug-induced movements often involve tongue thrusting, rolling, or chewing motions that the person cannot suppress. Stimulant medications used for Attention Deficit Hyperactivity Disorder have also been reported to cause compulsive lip and tongue biting.
Physical and Social Health Implications
The constant trauma inflicted by chronic tongue chewing can lead to physical and social complications. Physically, the tongue tissue suffers from chronic inflammation and the formation of ulcers and open sores that struggle to heal due to continuous irritation. This cycle of injury and re-injury can lead to scar tissue formation, which may permanently alter the tongue’s texture and, in severe cases, affect its mobility and sensitivity.
The physical damage also impacts dental and skeletal structures. Repetitive pressure against the teeth can contribute to excessive enamel wear, chips, or fractures. The constant jaw and tongue movements can also strain the temporomandibular joint (TMJ), potentially leading to pain and dysfunction in the jaw area. These consequences often lead to self-consciousness and anxiety in social settings, causing affected individuals to avoid public speaking or eating.
Approaches to Management and Treatment
Addressing chronic tongue chewing requires an approach tailored to the underlying cause, often starting with behavioral interventions. Habit Reversal Training (HRT) is a primary strategy that focuses on increasing awareness of the behavior and substituting it with an incompatible physical response. This involves identifying the specific situations and emotional states that trigger the chewing episodes.
For cases where the action is a learned habit, psychological support such as Cognitive Behavioral Therapy (CBT) can help manage associated stress and anxiety. If the behavior is primarily nocturnal or linked to teeth grinding (bruxism), a custom-fitted oral device, such as a mouthguard or splint, can be worn to protect the tongue and teeth from damage. These devices act as a physical barrier and can also help train the jaw muscles to relax.
If the behavior is involuntary and suspected to be a side effect of medication, consulting a physician is necessary to review and potentially adjust the current drug regimen. The physician may reduce the dose or switch to an alternative medication that does not carry the same risk of motor side effects. Dental professionals can also help by correcting any significant malocclusion or sharp dental edges that might be contributing to the habit.