You tip toe into your sleeping child's room for one last goodnight kiss, and expect to hear the sound of peaceful, quiet breathing. Except instead you hear his teeth grinding together. It gives you that shivery feeling, like nails on a chalkboard.

Is your child a tooth grinder? That gnashing and gnawing of teeth is called bruxism. And, it's common in kids. It can happen during deep sleep and when under stress. Kids usually do outgrow it though.

Why is your child clenching his teeth?

No one really knows why this happens exactly, although studies have been done. Some believe it's a response to the pain of another condition, such as an earache or teething. The clenching and grinding may help ease the pain. Or, it could be that the child's jaw is misaligned.

Stress may also be a big cause. When kids feel nervous or tense or angry, they might clench their jaws or grind their teeth. Some common stressors for kids include:

• Things school-related: tests, homework, projects
• Things in their personal lives: changes in routine such as divorce, the birth of a sibling, a move to a new house, or pressures from friends, bullying and so on
• Medical conditions: children with cerebral palsy, for example, or those taking certain medications

Is it harmful to your child's teeth or jaw?

Bruxism can go undetected with no harm done and eventually it's outgrown. Sometimes it can cause minor discomforts, such as headaches or earaches. In more severe cases, however, grinding of teeth can result in more serious problems, including:

• Worn down tooth enamel
• Chipped, fractured or lost teeth
• Sensitivity to hot and cold
• Facial pain and jaw conditions, such as temporomandibular joint disease (TMJ)

Is it treatable, if necessary?

Talk with your dentist. He or she may suggest a mouth guard that your child wears at night to stop grinding. If you believe her bruxism stems from stress, talk with her pediatrician about ways to reduce stress. This may include counseling, exercise and other methods.

Here are some other tips:

• Make sure your child avoids foods and drinks with caffeine, such as cola and chocolate.
• Urge him not to chew on pens or pencils, and perhaps limit and/or cut out gum.
• Teach your child how to relax his jaw. If you notice he's clenching, or if he catches it himself, he can put his tongue between his front teeth. This immediately relaxes the jaw.

If you have concerns about your child's grinding and clenching, bring it up with your dentist. Together you can find a solution that will work best for your child to uphold their oral health.