Tongue thrust also called as reverse swallow or immature swallow. In recent years the tongue thrust problems and the resultant oral features have come to the forefront of the progressive, clinical orthodontist’s attention. If the tongue was observed thrusting between and the teeth did not close in centric occlusion during swallowing, it was specified that a tongue thrust was present.
What is Tongue Thrust?
The tongue protrudes through the upper front teeth during swallowing, speech and while the tongue is at rest. Tongue thrust is the habit of sealing the mouth for swallowing by thrusting the top of the tongue forward against the lips.
Tongue thrust is normal in infants until approximately the age of 6 months. The loss of this normal infant behavior is one of the signs that the baby is ready to begin eating baby food. During infantile swallow the tongue is placed between the gum pads. After 6 months of age, several maturation events occur that alter the functioning of the orofacial muscles.
With the arrival of incisors the tongue assumes a retracted posture if the transition of infantile to mature swallow does not take place with the eruption of teeth then it leads to tongue thrust swallow. In a thrusted swallow the tongue is pushed up and forward and in mature swallow the tongue is pushed up and back. As a child develops a more mature swallow the back and sides of their tongue begin growing stronger and gain more control of movement.
At what age does a child usually exhibit a tongue thrust swallowing pattern?
A child exhibits a tongue thrust pattern from birth, because it is an infantile swallowing pattern. It is acceptable to have this swallowing pattern up to the age of four years. Most children will outgrow the infantile pattern and develop the mature pattern of swallowing, not developing a problematic tongue thrust. If the child has not naturally outgrow the pattern by age four, the thrust is strengthened becomes an issue, and will require a training program to correct the thrusting pattern.
During a normal swallow, the mid tongue should be placed on the roof of the mouth, not between the teeth. Placing the tongue between the teeth pushes the teeth apart and out.
What is the Effect of Tongue Thrust?
Tongue thrust can adversely affect the teeth and mouth. The affects are depends on intensity, duration, frequency and type of tongue thrust.
- Many people who tongue thrust have open bite; the force of the tongue against the teeth is an important factor in contributing to bad bite
- Speech is not frequently affected by the tongue thrust swallowing pattern. The ‘s’ sound is the one most affected an abnormal swallow will move teeth into abnormal positions and cause growth distortions of the face and teeth
- The tongue moves forward in an exaggerated way during speech and or swallowing. The tongue may lie too far forward during rest or may protrude between the upper and lower teeth during speech , swallowing and at rest
- Lip separation
- More erratic mandibular movements
- Increase in anterior face height
- Irregular tongue movements
- In a thrusted swallow the back and middle of the tongue are pretty non-active
- Reversal of orthodontic treatment
- Just like thumb sucking, tongue thrust exerts pressure against the front teeth pushing them out of alignment
What are the Causes of Tongue Thrust?
- Enlarged tongue(macroglossia)
- Thumb sucking
- Large tonsils
- Hereditary factors
- Tongue tie(ankyloglossia)
- Nasal congestion
- Certain types of artificial nipples used in feeding infants
- Upper respiratory tract infections
What are the Different Types of Tongue Thrusting?
Type 1-non deforming
Type2-deforming anterior tongue thrust
- Sub group1-anterior open bite
- Subgroup2-anterior proclination
- Subgroup3-posterior crossbite
Type3-deforming lateral tongue thrust
- Sub group-posterior open bite
- Subgroup2-posterior crossbite
- Subgroup3-deep overbite
Type4-deforming anterior and lateral tongue thrust
- Subgroup1-anterior and posterior open bite
- Subgroup2-proclination of anterior teeth
- Subgroup3-posterior crossbite
- Simple tongue thrust-normal tooth contact in posterior region, anterior open bite, contraction of lips, mentalis muscle and mandibular elevators
- Lateral tongue thrust-posterior open bite with tongue thrusting laterally
- Complex tongue thrusting-features are generalized open bite, absence of contraction of lip muscle
What is the Treatment plan for Tongue Thrusting?
The most proven and effective technique to solve the tongue thrust problem is by oral habit training. This is an exercise that reeducates the muscles associated with swallowing by changing the swallowing pattern. This method must be taught by a trained speech therapist.
- If an associated habit like thumb sucking is present, it must be treated first
- Speech therapy not indicated before the age of 8 years
- The patient may place an appliance similar to nightguard in the mouth at night, or may wear a more permanent device that can be removed or adjusted by a dentist
- Tongue tie should be corrected