Thumb sucking can be harmful for the mouth – find out how!

Children Thumb sucking

We see a lot of babies and very young children suck their thumb. It looks like a very innocuous and harmless habit; but only up to a certain age. As they get older it can be a difficult habit for a child to break with harmful consequences. Here are some of the ways it can damage your child’s dental health.

Why do babies suck their thumb?

Babies are born with the rooting and sucking reflexes, which give them a natural urge to put their thumbs or fingers into their mouth. This can happen even before the baby is born and sometimes seen on ultrasound images.

Thumb sucking calms them and makes them feel secure. Many parents use pacifiers and other teething toys for their children to suck on to something and relax them, sometimes it helps them fall asleep. The instinct usually subsides when the baby is older than six months. But as they get older babies suck their thumb when they are hungry, restless, tired or scared.

If this habit is not stopped after a certain age it causes long lasting damage to the child’s oral structures. It can also be a sign of emotional problems.

At What age should children stop sucking their thumb?

Typically thumb sucking is stopped naturally by a child between the ages of two to four years. But if it continues beyond age 5 years it can lead to permanent damage to the mouth. The American Academy of Pediatric Dentistry (AAPD) recommends that children stop their thumb-sucking habit by 5 years of age.  This gives the mouth the chance and time to readjust to its normal self before permanent teeth start to come in. So if you find your child sucking his/her thumb beyond this age consult a Pediatric dentist immediately. Some experts feel it should stop by age 3 years.

The factors that determine the effects

No two children are the same, so thumb sucking is also different in each child. The frequency, duration and intensity of the habit will change from one child to the other. These are the main factors that govern the amount of damage done. Out of these the duration is the most important one. So the longer the child engages in thumb sucking the worse will be the effects.


Effects of Thumb sucking

When your child sucks on the thumb, his/her tongue and muscles of the mouth move and exert pressure on teeth and jawbones. These forces cause the teeth to move away from their normal position as well as cause the underlying bone to remodel and reshape. As this is the age when your child’s bones are growing, the habit affects normal growth and development.

Here are some of the most common changes and effects seen:

1. Open bite in the front teeth:

The front teeth do not touch when the child bites down. This is the most common and severe effect of thumb sucking. The upper pushed up and forward, and lower front teeth are pushed down and back with inability to bite on the front teeth due to gaps between upper and lower teeth.

Children - thumbsucking

2. Cross bite in the back teeth

The upper back teeth sit inside the lower ones in a cris-cross manner when the child bites down. As the upper jaw bone gets narrow and constricted due to forces exerted by the musculature during the sucking motion.

3. Flaring of the front teeth

The upper front teeth are way ahead and flared outwards in comparison with the lower front teeth leading to what is called excess overjet.

4. Lips do not meet at rest:

The upper and lower lips are held apart due to prominent upper teeth and do not meet at rest.

5. Upper jaw growth is restricted and the palate/ the roof of the mouth gets altered and narrow and becomes more sensitive.

6. Speech

Thumb sucking changes the way your child swallows, eats and speaks. They lisp as the sucking can affect the jaw bone positioning.  It gets difficult to pronounce consonants like “D” and “T.” Many children with speech problems are unable to communicate effectively leading to frustration and lower self-esteem.

7. Skin problems

There are calluses or cracked skin on the thumb. The skin is constantly exposed to the saliva and it becomes susceptible to injuries, may peel or develop cracks or even bleed and becomes prone to infections of the skin. Plus germs from the thumb will affect the body adversely.

8. Psychological and social issues:

Poor appearance can lead to lower confidence and self-esteem. When an older child is seen thumb sucking he/she can be teased or mocked by peers and become the butt of the joke. 

How can my child stop thumb sucking?

Most children will stop the habit on their own between the ages of 2 – 4 years, but continuing beyond age 5 years will have long term effects.

Initially you can try to stop the habit at home. But if nothing works then it is wise to take the help of your child’s pediatric dentist.

But keep in mind that this habit does not mean your child has any physiological or developmental issues. It takes time to break any bad habit including thumb sucking. Research shows that a minimum of 30 days without the habit is what it takes to come out of it. Be patient, as it will take time. Don’t expect results overnight.

Positive reinforcement

This works much better than punishment. Praise him every time he refrains from doing it as positive reinforcement has shown to be significantly more successful and makes the child feel like they are on the same team as you.

Firstly have a conversation with your child and explain the dangers of prolonged thumb sucking and why it is important to stop. Decide on a reward, like a small toy, sticker or activity which they enjoy. Having a calendar also helps, give stars for each day they have not sucked thumb and on the weekends give a reward. Reminding gently along the way helps, but do not make a big deal or scold. Praise them profoundly when they stop.


They do it most when not doing anything with their hands! It’s a given. So keep their hands busy with activities – outdoor games or even while indoors activities like coloring, craft etc instead of just watching TV or playing games on the mobile.


Since there is strong psychological source to thumb sucking, try to understand and resolve the cause of the anxiety. If comfort or security is what your child is looking for then encourage her to switch to other things like a soft toy or a blanket.

Sometimes a child understands but can’t stop and needs a reminder. In this case you can bandage the thumb or put a sock on the hand before he/she falls asleep.  

 Your child’s pediatric dentist can help

Try the tactics on your own for some time, but if you find they are not working, then talk to your child’s pediatric dentist. There are appliances that are fitted to your child’s palate and act as a reminder to help them overcome the habit which are also known as habit breaking appliances.

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