Tongue thrusting is a common human behavioural pattern in which the tongue protrudes through the upper and lower front teeth during swallowing, speech, and while the tongue is at rest. Nearly all infants exhibit a swallowing pattern involving tongue protrusion, but by six months of age 
most lose this.Factors that can contribute to tongue thrusting include enlarged tongue, thumb sucking or large tonsils. The force of the tongue against the teeth results in space between the upper and lower front and is an important factor in contributing to a bad bite. The patient may be placed on an appliance similar to a night-guard in the mouth at night, or may wear a more permanent device that can be removed and adjusted by a dentist.
