An outdated term
Tongue thrust is ACTION where the tongue is pushing forward during swallowing.
In the past, this action was assumed to cause the open bite you see in the picture.
However, we now know this is not true. Swallowing does not have enough consistent pressure on the teeth to move them. However, TONGUE REST POSTURE, can and will move the teeth.
The tongue MUST rest on the roof of the mouth known as the palate. It is supposed to follow the arch of the teeth WITHOUT touching the teeth.
If the tongue rests low on the floor of the mouth OR against the teeth, damage can occur in a few different ways.
At night and during the day if the tongue does not rest on the palate, it will press against the teeth for long periods of time.
The tongue, like the controlled forces of braces, can move teeth, and it's a VERY powerful muscle.
The tongue RESTING on the teeth or floor of the mouth is one of the MAJOR causes of problems in tooth eruption, tooth alignment, and facial development in addition to problems with chewing, swallowing, digestion, JAW PAIN and HEADACHES!
The tongue is responsible for maintaining the upper dental arch. If the tongue doesn't rest on the palate over long periods of time, the upper arch will begin to narrow and the palate (roof of the mouth) will begin to vault upwards.
Narrowing of the upper dental arch not only affects the mouth, but it makes the nasal cavity smaller because the palate is ALSO the floor of the nasal cavity. This narrowing actually decreases the amount of air we are able to breathe!
Many professionals do not understand how much the tongue impacts the teeth, nor that it maintains the shape of upper dental arch. Because of this, applying braces will straighten the teeth while they are on, but as soon as they are removed, the tongue may push the teeth back out of alignment, especially if the retainers are not worn. This is because the UNDERLYING problem of the low tongue resting posture was NOT corrected.
For many it is also a symptom of an airway problem!
(which we will discuss on another page!)