Are you an ice-chomper or perhaps a nail-biter? These and four other “mouth habits” mean that you should start saving for dental work—you’re going to need it.

Brushing and flossing (and dentist visits) won’t save your teeth if you engage in mouth-mangling habits. Forget the obvious things such as smoking or chewing on pencils. Habits that seem innocuous actually can cause significant (and expensive) damage…


There’s a scientific name for nail-biting—onychophagia. It’s among the most common nervous habits and is listed in the Diagnostic and Statistical Manual of Mental Disorder, fifth edition (DSM-5, the official manual of mental disorders) because some people do it compulsively—in some cases, for hours a day.

Fingernails are harder than you might think, especially if you use nail polish. Constant nibbling can fracture tooth enamel. It damages the cuticle and soft tissue surrounding the nail and exposes your mouth to hand bacteria. It forces your jaw into a protruding position that puts painful pressure on the joint.

My advice: You have to be aware of a habit before you can stop it. An awful-tasting nail polish or cream (such as neem oil, Control-It! or Mavala Stop) will remind you of what you’re doing. People are more likely to bite their nails when they’re stressed, so it’s helpful to substitute healthier (and more soothing) activities—deep breathing, going for walks, etc. Or chew sugarless gum to dispel nervous energy and keep your mouth busy. Also, keep your nails short—they’re harder to bite.

Hard Brushing

As a dentist, I always encourage people to brush their teeth. Done correctly, it’s among the best ways to protect your teeth as well as your gums. But many people think that a soft touch won’t get the job done. They apply way too much force or use a brush that’s hard enough to clean bathroom grout.

Hard brushing abrades tooth enamel along with gums. It does even more damage to the tooth roots, which are softer than enamel. When I see patients with notches or abrasions in the roots, I know that they’re brushing too hard. Hint: Tooth sensitivity to cold temperatures or sweets can be caused by root damage due to brushing too hard.

My advice: Never buy a hard toothbrush. Those that are labeled “medium” still are too hard. Use only a soft brush. And even with a soft brush, don’t bear down when you’re brushing—use the lightest touch you can muster. Think “massage,” not “scrub.”

Helpful: Hold the brush (manual or electric) with your fingertips instead of clenching it in your fist. This makes it almost impossible to apply too much pressure.

Chewing Ice Cubes

Ice is harder than hard candy. According to the Mohs Scale of Mineral Hardness, it has a hardness of 1.5. That makes it a little harder than talc but not quite as hard as gypsum. No one would think to chew rocks, but that’s exactly what you’re doing when you munch the ice cubes in your drinks. It can cause ­microscopic cracks in tooth enamel, which increase the risk for decay and fracturing teeth.

My advice: If you can’t stop yourself from chomping ice from your drinks, quit putting it in drinks. Stick to chilled beverages without ice. Or use a straw to reduce temptation. Another option: Use ice chips. They’re smaller than cubes and less likely to crack your teeth.

All-Day Grazing

Snacking isn’t bad if your taste runs to nuts, fruits and vegetables. But many people who snack crave sweets. The ­average American consumes about 20 teaspoons of added sugar a day.

Bacteria in the mouth love sugar. They convert it to acids that damage the teeth as well as the gums.

People who eat a lot of sugary snacks have a much higher risk for cavities and periodontal disease (loss of gum and bone), the leading cause of tooth loss in adults.

My advice: Limit your snacking. Eat larger (nutritionally balanced) meals so that you feel full longer.

When you do snack, keep it healthy. Avoid the usual culprits—sweetened soft drinks…candy bars…hard candies, etc.

Also helpful: If you can’t brush after snacks, at least swish your mouth with water. It will remove some of the sugar and bacterial acids.

Using Teeth as Tools

This should be obvious, but many people don’t hesitate to use their teeth for all sorts of odd jobs—opening bags, snipping plastic tags off clothes, tearing open clamshell packages and even opening bottles.

I see a lot of patients who have chipped or fractured their teeth because they didn’t take the time to look for a pair of scissors or dig through the toolbox for pliers.

My advice: Don’t use your teeth as tools. You might think you’re saving time by nibbling off a price tag, but the eventual damage and repair will take longer than looking for the right tool—and will cost a lot more.

The Dangers of Grinding and Clenching Your Teeth

Australian researchers made a surprising discovery when they compared human skulls to those of other animals. Using sophisticated engineering software, they found that the human jaw actually ­generates more biting force than the jaws of great apes. When you use all of your jaw muscles to bite down, you’re generating a force as great as 55 pounds.

That’s what allows us to chew hard foods. The downside is that it’s more than enough to fracture the teeth and even damage the jaw joints. Some of the worst damage I see in my practice comes from bruxism, clenching or grinding the teeth during sleep or times of high stress. It can cause visible wear and flattening of the tooth surfaces.

People who grind their teeth during sleep, known as nocturnal grinders, can protect themselves by wearing a customized mouth guard. Daytime grinders are a bigger challenge because they don’t even know they’re doing it (and would be unlikely to wear mouth guards while they’re awake).

My advice: Start with relaxation exercises. Grinding/clenching almost always increases during times of stress, anger or even deep concentration. People who manage their stress with activities such as yoga, meditation or regular workouts will naturally grind less.

Helpful: The next time you’re feeling stressed, pay attention to your shoulders. You’ll probably notice that they’re tight and hunched upward toward your neck. It’s impossible to relax when the shoulders are tensed. Make a conscious effort to relax your shoulders and let them “drop.” You’ll feel less tension the moment you do this.