Sleep should be a calm, peaceful endeavour. But for people with sleep bruxism - tooth-grinding or clenching at night - sleep can become a noisy, gnashing, and not-so-restful situation.

You may notice yourself gritting your teeth at tense moments. Sleep bruxism, however, happens when you're conked out, and so it can often go undetected. Those most likely to notice it are dentists spotting worn-down or fractured teeth - or bed-mates kept awake through the night by the grating, rasping sounds of teeth sliding across teeth.

Occasionally bruxism causes no symptoms at all. But left unchecked, sleep bruxism can lead to complications, including damaged teeth, tension headaches, and jaw and facial pain. It may even trigger earaches due to referred pain or because of the proximity of the ear canal to the muscles of the jaw. Grinding, clenched teeth can also disrupt sleep by awakening "bruxers" and those who sleep near them.

The causes of bruxism remain somewhat unclear, though a misaligned bite may be to blame in some cases. Stress and anxiety are thought to trigger or make the nocturnal grinding worse. People with sleep apnea tend to have a higher risk of bruxism. So do loud snorers, those who drink lots of alcohol or caffeine, and smokers, though none of these risk factors have been targeted as a cause.

Around 2 or 3 out of every 10 children grind and clench and the condition generally goes away by adolescence. Bruxism signs to watch out for in kids include the tell-tale grinding noise during sleep and complaints of a sore jaw or face in the morning.

In most cases, treatment isn't necessary since kids will outgrow it and many adults don't have severe enough symptoms to require treatment.

Since most of the grinding and clenching of bruxism happens while one sleeps, it can naturally be tricky to control. During the day, practice a neutral mouth position: tongue rested upward toward the top of your mouth, teeth apart, and lips together. To ease pain, gently massage or apply ice or wet heat to sore jaw muscles. Avoid hard foods or chewing gum. If stress seems to be at the root of your teeth-gnashing, reduce tension and find ways to relax. Other things that can help include avoiding smoking before bed, reducing alcohol intake, avoiding sleeping on your back, and moving the TV or computer from the bedroom.

Seek help from your doctor or dentist if teeth become visibly worn or damaged, if teeth become sensitive, or if pain spreads and worsens. You may be sent to a specialist in jaw pain or fitted for a splint or mouth guard to be worn when you sleep. You may also be prescribed medications to help relax muscles and reduce pain.