Don't be offended if your dentist asks whether you bite your nails. Nail biting is a bad habit for many reasons. Besides the oral hygiene issues, biting your fingernails can affect your oral health and damage your teeth. Your dentist may be asking because he or she noticed some concerning signs.
Types of Damage
Damage to your teeth that nail biting can cause includes:
Cracked or chipped teeth—the result of tiny fractures that biting down on hard nails can cause
Dental attrition of front teeth—wearing down of the teeth, which can lead to misshapen teeth
Tooth sensitivity and pain from erosion of tooth enamel
Dental resorption—breakdown of the tooth's structure
Constant nail biting can weaken the roots of teeth, particularly during orthodontic treatment. If you wear braces, the added pressure of biting your nails may further weaken the structure of your teeth above and below the gum line. Nail biting can also cause teeth to shift, affecting tooth alignment and the results of orthodontic treatment. Worse yet, the damage nail biting can cause doesn't stop with these dental problems.
Although nail biting doesn't cause gum disease, the habit can damage gum tissue. Uneven and jagged fingernails can tear gum tissue and the soft tissue lining the inside of the lips, creating a pathway for infection-causing bacteria to enter. Bacteria can cause infections in your gums and may spread to other parts of your body through your blood by way of the mouth.
Biting your fingernails can also increase your risk for bruxism—teeth grinding that can cause headaches, sensitive teeth, and facial pain. While constant nail biting wears down tooth enamel, tooth grinding puts pressure on your teeth, and that can cause tiny fractures.
Along with worn tooth enamel, bruxism can lead to receding gums and even tooth loss. The downward force of grinding or clenching your teeth may cause the gums to pull away from the teeth. While nail biting isn't a direct cause of gum disease, if teeth grinding or clenching results, tooth roots can eventually become exposed as the gums recede.
Receding gums create spaces where bacteria can enter and cause infection below the gum. Also, without adequate support from the gums and jaw bone, teeth can loosen and tooth loss can occur.
If problems with your teeth and gums aren't enough to deter you from nail biting, maybe the knowledge that this bad habit can cause temporomandibular joint (TMJ) problems will. TMJ is a disorder that causes problems with the jaw joint and the muscles that control jaw movements.
Biting down puts pressure on the joint that can lead to symptoms such as jaw and facial pain and even pain in the neck and shoulders. You may have trouble opening your mouth and chewing or may suffer toothaches, earaches, headaches, and facial swelling. Symptoms of temporomandibular joint disorder can affect one or both sides of the jaw.