Thumb sucking is common in young children. Most kids will give up the habit between the age of two and four but there are plenty of children who keep doing it until they are much older.

For many kids, sucking their thumb won’t cause any problems. For others – particularly those who thumb suck past the age of five –  it can cause real problems that require orthodontic treatment.

Most parents are relieved to hear that their child under the age of five shouldn’t be pressured to stop the habit. Past that age, parents need to be aware that it could alter the alignment of their child’s teeth and jaw and should consider a consultation with an Orthodontist to see if early intervention treatment is needed.


Does Thumb Sucking Cause Orthodontic Problems?

Yes, in some children, thumb and finger sucking past the age of five can cause problems such as:

Teeth Alignment

The most obvious sign that a child sucks their thumb is changes to the front teeth. The sucked thumb or finger can cause the upper front teeth to protrude forward. The constant pressure from the hand in their mouth can also cause the lower front teeth to tip forward.


While not as common as the changes to teeth, thumb sucking can change the shape of a child’s jaw. The upper jaw can narrow so it doesn’t match the bottom jaw. A cross-bite may occur because the upper and lower teeth don’t fit together.

An open bite can also occur with thumb sucking. The upper teeth don’t overlap the bottom teeth when the back teeth are together. The thumb or finger has created an opening between the top and bottom front teeth and prevents them from meeting.


A child’s speech can be impacted by bucked teeth or an open bite. Straight front teeth help pronounce some letters. A lisp may be heard when they say the s and z sounds. Without speech therapy and orthodontic treatment later on, the lisp can remain into adulthood.

Face Shape

The shape of our jaws influences the shape of our face. An overbite where the front teeth are pushed forward to accommodate the thumb, is likely to change the overall look and shape of a child’s face. Orthodontic treatment can reverse the face shape changes.


Factors that Influence the Severity of the Problem

There are three main factors that determine the likelihood of thumb and finger sucking causing orthodontic problems.


If the thumb sucking habit doesn’t last long or the child does not suck their thumb for long on a given day, then it’s unlikely they will do any damage to their teeth or jaw.


Some children will only suck their thumb for a short time during the day while other children will suck their thumb all day and even night while they sleep. It’s when the frequency is high that children are most at risk of doing damage.

Type of Sucking

Not all thumb sucking is the same. Some children just let their finger sit in their mouth but others use more force. The harder a child sucks on their finger, the more damage they can do.

Dummies vs Thumb Sucking

Parents will often wonder if they should have introduced their baby to a dummy rather than let them suck on their thumb, however a dummy isn’t much better. They can still cause jaw and teeth alignment problems if they use it long and often enough.

Research shows that there can be significant dental arch and occlusion characteristics in dummy users between 24 and 36 months compared to children who stopped using one by the age of 12 months. However, significant problems occur in long-term users after the age of five but ideally the dummy should be discarded before 3 years of age. No shape or brand of dummy is better than another at reducing teeth and jaw risks.


When Should Children Quit Thumb Sucking?

Until the age of five, thumb suckers shouldn’t change the shape of their jaw. Their baby teeth may be out of line a little but the greatest concern is the jaw which will require orthodontic work to treat the alignment problem.

After the age of five their jaw shape is more like to be impacted and the teeth are more likely be misaligned. It’s a good idea to try getting your child out of the habit once they have their fifth birthday.


How Can I Stop My Child From Sucking Their Thumb or Fingers?

It’s not easy. Thumb sucking is a difficult habit to break.

When parents want kids to give up their dummy, they can take it off them and throw it out. With thumb or finger sucking, their hand is always there.

To help your child stop sucking their thumb, you can try one or more of the following tactics:

  1. Remind your child to take their hand out whenever you see them sucking their thumb. Ask positively rather than threaten them with punishment for thumb sucking.
  2. Offer a reward that appeals to your child if they stop sucking their thumb for a certain time.
  3. Wearing a glove can remind a child not to put their hand in their mouth.
  4. Applying nail polish can act as a reminder and encouragement not to damage their manicure by putting their thumb in their mouth.
  5. Keep them busy. If they are doing things with their hands, particularly if they are dirty, they are less likely to put their hands in their mouth.
  6. A sour tasting liquid on their fingers to make them less appealing
  7. For older kids, an orthodontic plate can make it less enticing to put their thumb in if the space has been taken up by the plate.

Give them plenty of hugs and support while they give up as it can feel like they are losing their best friend.

It is normal to see your child make good progress then slip back into the habit. When this happens, keep encouraging your child with praise about how well they are doing.

Children, particularly those who are strong-willed, can dig their heels in when they feel they are being pressured. Be patient, use positive reinforcement and it will happen with time.


How Braces Can Help

The jaw and teeth misalignment caused by thumb sucking can be corrected with braces. but its is probably better to try to intercept the problem prior to all the adult teeth emerging. Fixed tongue or thumb/finger guards may be considered  at 6-8 years of age and are found to be most effective. Most complex orthodontic work happens after adult teeth are through but it’s best for your child to see an orthodontist by the age of 10. If the jaw shape has been altered, an orthodontist may recommend starting treatment early so they can work with the growing jaw before the palate fuses if expansion of the narrow jaw is required.

If a child’s baby front teeth are protruded, they may benefit from a plate or a fixed tongue of thumb/finger guard . A wire in a plate can pull the teeth back or the guard may facilitate spontaneous correction to reduce the chance of being bullied and reduce the risk of damaging their teeth and gums in an accident.

If you have concerns about your child’s thumb sucking habit, speak to an orthodontist. We’ll be able to tell you if the habit has caused any long-term problems and assess the chances of more problems developing if your child continues to suck their thumb. Use this link to find an orthodontist near you!