The clinical name is onychophagia. Nearly a third of all Americans deal with it regularly, and that percentage increases among teenagers. Nail biting is a common habit that, at its surface, seems relatively harmless. However, if you want to preserve the integrity of your pearly whites, the time to mitigate the compulsion is now.
Teeth are tough, and thank goodness. They put up with a lot from us, but if we want them to last, we shouldn’t take advantage of them. Teeth are suitable for food and nothing else. You should not use your teeth to open packages, bottles, or anything else, and even though teeth may seem stronger than fingernails, there are many reasons that nail biting is not good for your teeth.

Keratin
If you had the habit of biting a horse’s hoof every time you were stressed, you’d know pretty quickly that the behavior wasn’t good for you. It turns out that horses’ hooves and human nails are made of the same substance: keratin. Keratin is a fibrous protein that forms the structure of many biological features, including scales, feathers, and the epithelial cells in the outermost layer of your skin. When it builds up on the ends of your fingers and toes, keratin is designed to protect the delicate nerve centers of those digits. It is accordingly relatively tough and not good on the enamel.
The Problems of Nail Biting
Nail biting is a lose-lose situation, damaging to nails, nail beds, and teeth. The effects can be subtle, but they are many.

Structural Teeth Damage
The grinding pressure of nail biting can cause hairline cracks within teeth to form. These can quickly go from a minor problem to requiring extensive dental repairs. Biting your nails can also chip your teeth, which can be unsightly, and the repairs can be expensive. The need for repair in the case of a chip is much more apparent.
Bruxism
Nail biting instills a habit of bruxism, the propensity to grind, gnash or clench your teeth. If you bite your nails when you are nervous or stressed, you train your body to default to a bruxistic response every time you experience such emotions.
Decreased Longevity
Perhaps the most prevalent problem with nail biting is that the grinding action can erode tooth enamel. Enamel cannot be replaced when it is gone, leaving your teeth vulnerable to decay.
Bacterial Spread
Having a small child means telling them constantly to stop putting things in their mouths. This is often because of a choking hazard, but it’s also because we “don’t know where that thing’s been.” The same principle applies when putting fingernails in the mouth. No matter how frequently you wash your hands, putting them into your mouth introduces bacteria that is better outside of the body.
Gum Damage
Displaced bacteria introduced into the mouth from one’s hands can lead to gingivitis—gum disease. Nail biting also subtly shifts the teeth within the gums, making people who have already had orthodontia done nervous and introducing gaps in the gums that can leave them vulnerable to disease.

Fighting the Urge
There are many suggestions in circulation for how to quit compulsive nail biting. While it may take a few tricks in conjunction and the process may be gradual, if you want to kick nail biting to the curb, try some of the following suggestions:
- Cut your nails short—If there is not much to bite, it can discourage that compulsive response.
- Paint your nails—If you get a manicure, it may cause you to think twice about ruining the polish. If you paint your nails at home, use a bitter polish. The taste and texture of flakey nail polish in your mouth may discourage further biting.
- Try alternatives—The compulsion to be chewing something may be filled by chewing gum.
- Start slow—If stopping cold turkey doesn’t seem feasible, try to gradually break the habit. Cover one nail, perhaps the one most commonly bitten, then add more coverings over time.
In the fight against nail biting, you are not alone. Speak with your dentist about ways to kick the habit to the curb so you can protect your smile.