Tongue, breathing and habits

Question 1

Where should my tongue sit at rest (when it's relaxed)?

Accepted Answer

The correct resting position of the tongue – that is, when we aren't speaking or swallowing – is with its tip pressed against the palate just behind the upper front teeth, and the back of the tongue slightly lowered. As a rule, the tip of the tongue should sit where you make the sound ‘d’. In some people, however, the tongue rests in the wrong position – most often it stays down by the lower teeth, without touching the palate at rest. In this case, the tongue encourages the lower jaw to widen while the upper jaw stays narrow, which is often seen in patients with an underbite (reverse bite) or crossbite. There is also the so-called ‘tongue thrust’, where the tongue presses on the teeth from the inside outwards. Instead of resting, it actively pushes the front teeth forward, causing them to tip incorrectly. Any deviation from the correct tongue position can affect the development of the jaws and the alignment of the teeth, which is why it is important to correct it.

Question 2

Can my tongue push my teeth out of place?

Accepted Answer

The tongue is a very strong muscle. It can exert pressure of 400 to 800 grams per square centimetre. Moving a tooth requires a minimum force of just 30 grams. Normal tongue movements don't move our teeth if the bone around them is completely healthy. This is because the tongue pushes on the teeth from the inside, but on the outside this force is balanced by the muscles of the lips and cheeks. If the tongue sits in an abnormal position or presses constantly on the teeth in one direction, then given how much force it can apply to a tooth, we can expect it to shift the teeth. Not only that – the force the tongue exerts is greater than that of braces. That is why, when an incorrect tongue position or faulty swallowing pattern is found and the problem isn't corrected, orthodontic treatment may not be effective, or part of the result may be lost after treatment ends.

Question 3

Can a bad tongue position cause misshapen jaws?

Accepted Answer

The tongue has the strength and ability to ‘mould’ not only the shape of the dental arch but also the shape and size of the jaws themselves. As I mentioned, the tongue should rest against the palate – that is, at the upper jaw. If it doesn't sit there, the upper jaw stays narrow and underdeveloped. If the tongue rests down by the lower teeth, it drives the growth of the lower jaw, which becomes the wider of the two. All these changes are possible while the jaws are still growing. Once growth has finished, the tongue affects only the position of the teeth. More often than not, the incorrect tongue position starts in childhood, and the changes we see in patients are in the jaws.

Question 4

Can teeth straighten without braces if a bad tongue position is corrected?

Accepted Answer

One of the orthodontist's most important tasks with children is to spot any harmful habits. These can include incorrect tongue position, the tongue pushing against the teeth when swallowing, and breathing through an open mouth. The earlier such a problem is identified and corrected, the more likely it is that the jaws will develop normally without the need to wear appliances. Ideally, harmful habits should be corrected while the child still has baby teeth. The change from baby to permanent teeth involves major changes in the jaws, and if the harmful habit is stopped before this period, the jaws can develop normally.

Question 5

Can braces straighten my teeth without correcting an incorrect tongue position?

Accepted Answer

Braces and aligners apply force to the teeth in order to move them, but this force is weaker than the tongue's. If the tongue constantly works against them, the orthodontic problem may not be fully corrected. In some cases we still manage to finish with well-aligned teeth, but if the tongue keeps applying the wrong pressure after treatment ends, the result relapses.

Question 6

Can an incorrect tongue position make my teeth move back after treatment?

Accepted Answer

Unfortunately, no retainer is strong enough to resist the action of the tongue. If we use a fixed retainer (a thin wire bonded behind the teeth), the tongue is able to push all the front teeth forward together, since they are bonded to the wire. If we use a removable retainer of any kind, it doesn't protect the teeth from the tongue during the day. It is entirely possible that, if the tongue's bad habit hasn't been changed, the teeth will shift after treatment and even go back to their original position.

Question 7

What can happen to my jaws and teeth if I breathe through my mouth?

Accepted Answer

When a patient breathes through their mouth, the tongue drops down towards the lower teeth to let air into the mouth. This causes the teeth to part slightly and the mouth to open. Without firm contact between them, the teeth over-erupt, because they naturally tend to keep growing until they meet. This process can lead to the face becoming longer. In addition, mouth breathing leads to a number of other effects, such as: a narrow upper jaw, a high, dome-shaped palate, a wide lower jaw, an open bite at the front teeth and a crossbite at the back teeth. The teeth also dry out, making them more prone to decay, and viruses and bacteria enter the body more easily, increasing the risk of frequent illness. These changes most often appear in childhood, while the jaws are still growing. If breathing is corrected in time and air starts to pass mainly through the nose, some of these unfavourable effects on jaw development can be offset and minimised.

Question 8

What is the latest age my child should stop using a dummy or sucking their finger so it doesn't affect their jaws?

Accepted Answer

Using a dummy with a shape approved by paediatricians is normal and doesn't cause the jaws to become misshapen in the first two years of life. Once all the baby teeth have come through, at around 2.5 years, dummy use should stop. Sometimes children make up for the missing dummy by sucking their thumb, but the shape of the thumb has a much more negative effect on jaw growth, so you need to be careful this doesn't happen. If necessary, it is better to let your child use the dummy for longer than to have them replace it with a finger or another object.

Question 9

What is infantile swallowing and what problems can it cause?

Accepted Answer

Before a baby has any teeth, the tongue sits between the two jaws so that the baby can swallow without liquid escaping from the mouth. Once the baby teeth come through, they provide the necessary barrier, and the tongue should instinctively move back behind the teeth. In some children, and sometimes even in adults, the habit of placing the tongue between the teeth or pushing them forward when swallowing persists as a faulty swallowing pattern. The tongue moves forward and the lips tighten to help push the food or liquid towards the throat. This tightening of the lip muscles is accompanied by wrinkling of the skin on the chin and is called a ‘lip seal’. If the child has an orthodontic check-up, this problem is picked up in time, before it has a lasting effect on the teeth and jaws. This type of swallowing is called ‘infantile’ because it is typical of early childhood. The problems this faulty pattern leads to are the teeth being pushed forward and an open bite. Sometimes the problem is combined with an incorrect tongue position at rest. In that case we can also expect a wide lower jaw, a narrow upper jaw and a crossbite.

Question 10

What role does a speech therapist play in successful orthodontic treatment?

Accepted Answer

A speech therapist is the specialist we usually see when there is a problem with speech. As well as correcting mispronounced sounds, they also work on the correct position of the tongue in the mouth, which speech also depends on. This specialist is an essential part of any treatment aimed at correcting an incorrect tongue position and infantile swallowing. They give the child a series of exercises to train the tongue and check that the child learns them and does them regularly. Of course, the orthodontist can also give exercises to help correct the tongue, but in my view the best thing for the patient in these cases is collaboration between the different specialists.

Question 11

Can chewing on only one side wear down my teeth and make my jaw crooked?

Accepted Answer

Regularly chewing on only one side is often a habit, or something done without realising. It may have started because chewing on one side was temporarily impossible – for example, because of a sore on the gum, or an extracted or painful tooth. If this habit goes on long enough, the consequences become obvious: wear of the teeth on the chewing side, the lower jaw sliding towards that same side and the centre line of the lower teeth shifting, possible overloading of the jaw joint (TMJ) and pain, and facial asymmetry because the facial muscles on the two sides have developed differently. When there is no objective reason to chew on one side, this harmful habit needs to be broken.

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