For many people, lip biting is just an occasional nervous habit. However, other people may chronically bite their lips due to an underlying medical condition. Here are some of the many conditions that can cause this oral habit, including dental conditions, psychological conditions and developmental disorders.
The temporomandibular joint (TMJ), which connects your jawbone to your skull, is one of the most complex joints in the body, according to the Canadian Dental Association (CDA). Disorders of this joint can be caused by numerous factors, such as arthritis or injuries to the jaw. People with TMJ disorders may experience many different symptoms, such as pain in the jaw joint or trouble opening and closing the mouth.
A study published in the Journal of Clinical & Diagnostic Research found that lip biting is also a common symptom of TMJ disorders, with 37 percent of the studied individuals exhibiting the habit of biting their lips or other objects.
Malocclusion means the upper and lower teeth aren't aligned properly. The National Institutes of Health (NIH) explains that your teeth may be misaligned if your upper and lower jaws aren't the same size. Extra teeth, abnormally shaped teeth or missing teeth are some other possible causes of misalignment.
Most teeth alignment problems are minor and don't need any treatment, although in some cases, individuals may experience difficulty or discomfort when biting or chewing. Repetitive lip biting in children with an existing malocclusion can impede correction of the improper alignment, according to the textbook Pediatric Dentistry.
Other Health Conditions
Dental conditions such as a TMJ disorder and malocclusion aren't the only possible scenarios in which individuals bite their lips. Many other health conditions can also result in this oral habit.
Sometimes, psychological conditions can cause lip biting. The Anxiety and Depression Association of America (ADAA) explains that body-focused repetitive behaviors (BFRBs) are one of these disorders. People with BFRBs may repeatedly pull their hair, pick their skin, bite their lips or perform other repetitive actions.
Individuals with autism may also have a tendency toward certain self-harm behaviors, such as biting their lips, according to an article published in the International Journal of Clinical Pediatric Dentistry.
If you often bite your lips, or if you have a child with this habit, see a dentist. There are many treatments available based on the underlying cause.
If your dentist suspects a TMJ disorder is to blame, they may suggest home remedies such as massaging the jaw muscles or limiting your diet to soft foods, according to the CDA. If necessary, they may prescribe medications to help ease pain and inflammation in the jaw joint. Your dentist may even recommend a night guard or splint, which is a clear plastic device that fits over your teeth, to help your jaw muscles relax. Referrals to other medical specialists, such as physiotherapists or oral surgeons, may sometimes be needed to treat TMJ disorders.
Orthodontic treatment may be required to correct malocclusion and its associated issues. Your dentist may recommend braces or other orthodontic appliances to adjust the positioning of your teeth. If overcrowding is part of the malocclusion problem, one or more teeth may need to be extracted to make room, as the NIH explains. In rare cases, a patient may need surgery to reshape the jaw.
Psychological and developmental causes of lip biting aren't treated by dentists, so your dentist may recommend seeing your family doctor or an appropriate specialist. BFRBs are treated by mental health providers who specialize in these disorders, and the treatment may include identifying triggers for the behavior, according to the ADAA. The Mayo Clinic also notes that children with autism may receive treatment from a specialized provider, such as a child psychiatrist or psychologist.
Rest assured that occasional lip biting likely isn't a problem. Chronic biting of the lips, however, can be a distressing habit. If you're concerned about how often you're biting your lips or notice your child has developed the habit, talk to your dentist or healthcare provider.