Lots of people have nervous habits, such as lip biting, cheek chewing, nail biting, and pencil chewing. Though they may seem harmless, these habits can be detrimental to your oral health, leading to issues with your bite (occlusion) and/or the temporomandibular joints on either side of your jaw. At Trillium Dental, we offer Invisalign® and TMJ treatments to address these issues. So what is the cause of nervous habits like lip biting? Our family dentists will discuss this condition below.

Causes of BFRBs

Most often, lip biting, cheek chewing, and other body-focused repetitive behaviors (BFRBs) have an underlying psychological cause. Anxiety is a common cause of BFRBs, as is the physiological response to fear and stress. When we are overwhelmed, we create coping mechanisms to provide a distraction from the emotional pain we are experiencing — in this case, an anxiety disorder or a dangerous or stressful situation.

What’s interesting about BFRBs is that lots of people don’t even know when they have these nervous habits. In fact, you could be doing one right now subconsciously. Since these behaviors are compulsive, often people don’t know about them until the consequences start to emerge. For example, people who bite their lips will start to develop painful sores on the lips, as well as bleeding lips, swollen lips, and redness. The same goes for nail biters; you might not realize how much you’re biting your nails until your fingertips become sore or inflamed.

If you are suffering from a BFRB, this can be a difficult habit to break. This is especially true for people who deal with anxiety or have a lot of stress, as the only way to prevent the painful consequences of these nervous habits is to get to the root of the issue. For many people, therapy, medication, and lifestyle changes (e.g. yoga, meditation, sleep, and a balanced diet) can help reduce stress, as well as the BFRBs that come with it.


There are many consequences of BFRBs, depending on the nervous habits that are expressed. It is not uncommon for nail biters to experience ingrown nails, fingernail infections, and a host of tooth problems, such as tooth fractures, filed-down teeth, and an increased risk of gingivitis. For lip and cheek biters, the most obvious consequences are swollen, torn up lips and mouth sores.

People who express these compulsive BFRBs are also at a greater risk of causing damage to the temporomandibular joint and the integrity of their teeth. Chronic BFRBs can lead to the following conditions:


TMJ disorders, or TMJDs, refer to any kind of damage that has occurred to one or both temporomandibular joints, which are located in front of the ears on both sides of the face. TMJ disorders often result in a popping jaw and jaw pain, which makes it more difficult to open and close your mouth fully. Patients may also experience discomfort while chewing, as well as lockjaw, headaches, and earaches. Many people with TMJ disorders also have an uneven bite or crooked teeth (major causes of TMJ disorder), which can make symptoms even more unpleasant.

Most common in women ages 30-50, TMJ disorder is a condition that affects many adults around the world — especially people with anxiety, panic disorders, and chronic stress. Fortunately, there are many things you can do to alleviate TMJ pain, such as dental treatment using a transcutaneous electrical nerve stimulation (TENS) unit to relax the facial muscles and correct your bite. Night guards can also help prevent people from clenching or grinding their teeth at night, which can cause inflammation in the temporomandibular joints. Other TMJ treatments include nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce swelling and jaw pain, as well as hot and cold compresses. You can also massage the area to help loosen the jaw muscles, or do meditation or progressive muscle relaxation.

In some cases, corrective dental treatment is required to treat TMJ disorders. Your dentist might use the TENS unit to realign your jaw with a custom-made orthotic, or they might make splints to help reposition the jaw. Surgery may be required to correct jaw abnormalities, but this is fairly rare. Most of the time, TMJ symptoms subside after a few weeks, with the recovery time being even less if you correct poor habits (like BFRBs) and learn how to manage your stress in a healthier way. Other causes of TMJ disorders, such as facial trauma, arthritis, dislocation, poor dental health, or structural jaw problems, will need to be addressed by your family dentist and/or general practitioner in order to determine the right treatment plan.


The other main consequence of lip biting and other nervous habits is crooked teeth. When you chew on your lips, cheeks, nails, or other objects, you’re forcing your jaw into an unnatural position, which can cause the teeth to shift. BFRBs like nail biting and pencil chewing can also cause the roots of the teeth to become deformed, which results in crooked, unhealthy teeth. The last thing you want is to have a root canal because the nerves under your teeth become damaged or infected, and you certainly don’t want to have your teeth break or splinter either.

Hardly anyone has perfect teeth to begin with, and if you do, you’re one of the lucky ones! If you have misaligned teeth, there are many teeth straightening methods available today that can help you get the smile you’ve always wanted. Braces and Invisalign® are two easy ways to correct your bite and straighten your teeth, and you’d be surprised at how your self-esteem increases and your anxiety subsides when you feel confident in your smile. Got perfect teeth? Don’t jeopardize your oral health by chewing on things that aren’t food, like nails, pencils, ice cubes, and those pesky clothing tags.


If you are suffering from TMJ disorder, misaligned teeth, or any other consequence of BFRBs, our dentists are here to help. We’ll take x-rays and perform a dental exam to determine the right treatment plan for you, whether that be TMJ therapy with our TENS unit, oral surgery, or just a change in lifestyle habits. Contact us today to learn more, or book an appointment online at Trillium Dental in Ottawa!