Researchers still do not know for sure what causes people to grind or clench their teeth. Some think stress could be a factor but often there are multiple factors which contribute to this condition. In fact, the latest research suggests a relationship between sleep apnea (a serious sleep disorder where a person’s breathing is interrupted during sleep) and bruxism. In preschoolers, research reports an association between grinding their teeth or clenching their jaws and signs of stress such as anxiety or social withdrawal.

Older children also can develop this habit when they are losing their baby teeth and their permanent teeth are coming in.

Nail biting also may lead to grinding of teeth or jaw clenching. Some children outgrow this, but often adults who grind their teeth or clench their jaws did so as children. Like many habits, people may not be aware that they grind or clench their teeth. You may even do it in your sleep. Tobacco and alcohol use may increase the chances of such destructive habits during sleep.

Large amounts of caffeine (8 or more cups of coffee a day) may also increase this risk. Some medications or illegal drugs may also one to thrust their jaws as well.