What is thumb sucking?

Thumb sucking in infants is common. In most cases, babies and toddlers stop sucking their thumb by themselves or with support from their parents or carers.

If your child continues to suck their thumb as they get older, it can cause problems with their developing teeth and jaws.

Thumb sucking, as well as sucking other fingers, a dummy or a blanket is known as a non-nutritive sucking habit (NNSH).

Why do babies and children suck their thumbs?

In their first year, up to 1 in 3 babies suck their thumb or fingers. Sucking is a natural reflex in newborns that helps them feed. In some babies and children, thumb sucking or sucking other fingers becomes a comforting behaviour. It can help them:

• self-soothe
• feel secure
• go to sleep

Is thumb sucking bad for teeth?

Many children who suck their thumb do not have problems with their teeth, but some do. This may depend on:

• how often your child sucks their thumb
• the angle of your child's thumb in their mouth
• how hard your child sucks their thumb
• genetic factors

At around 6 years of age, your child's adult teeth start to grow. If your child continues to suck their thumb at this age, their adult teeth may grow in the wrong position. The longer your child continues to suck their thumb, the worse the damage to their bite and teeth.

Your child can develop some of these problems:

• overbite — upper front teeth and jaw being pushed upwards and out
• open bite — a gap between your child's upper and lower teeth. Your child may not be able to bite their front teeth together.
• the palate (roof of the mouth) becoming pushed up and narrow

Your child may need dental treatment to fix these problems. Genetic factors may also mean that your child is more likely to have teeth that do not align well in their mouth.

Problems with your child's teeth and bite can also affect their speech. Your child may develop a lisp.

How can I stop my child sucking their thumb?

There are different methods you can try to stop your child from sucking their thumb. Examples include:

• behaviour modification — using reward or habit-changing strategies
• barrier techniques — putting something on their thumb to make sucking harder
• orthodontic treatment — see a dentist or orthodontist for advice

Behaviour modification

There are many different types of behavioural interventions, for example, positive reinforcement. With this method, you will support, encourage and remind your child to stop sucking in a positive way. Here are some things you might try:

• Praise your child, for example, "look how grown up you are when you do not suck your thumb".
• Use a chart or calendar to record your child's progress and offer stickers or rewards when they reduce or stop their behaviour.
• Plan a small celebration or special activity (like a trip to the park) for when your child goes a set number of days without sucking their thumb.

Barrier techniques

A barrier technique involves applying something that tastes bitter, an adhesive (sticky) plaster or a glove onto your child's thumb to try to stop them sucking it.

Orthodontic treatment

If your child is older and still sucking their thumb, a special mouth appliance can help them stop. This is a permanent device that stays on the inside of their mouth for a few years. You cannot see it from the outside. It is fitted by a dentist and can make thumb sucking harder or less enjoyable.

You can try a few methods at once.

Remember, many children will stop sucking their thumb by themselves by the time they are 4 years old. Others will stop when they get to school.

Thumb sucking is a habit that may take some time to stop. Try to be patient and positive while helping your child. Encourage them to want to stop themselves. Try not to nag them in a negative way, as this can make your child defensive.

There are also strategies that may help your child to stop using a dummy.

When to get help for thumb sucking habits

If your child continues to suck their thumb around the age when starting school (age 4 to 7 years) and has also developed problems with their teeth and speech, you can discuss your concerns with a:

• dentist
• orthodontist
• speech pathologist
• paediatrician

It is best to wait until your child is old enough to understand and accept responsibility to break the habit.

Resources and support

For more information and further tips on thumb sucking, visit:

• Queensland Government website for more information about thumb sucking and dummies.
• Orthodontics Australia to watch a video and learn more about why your child may suck their thumb.

Call Pregnancy, Birth and Baby to speak to a maternal child health nurse on 1800 882 436 or video call. Available from 7 am to midnight (AET), 7 days a week (including public holidays).

Read more about dental care for babies and children.

Read more about dental benefits for kids (CDBS).

Read more about speech problems in children.

FIND A HEALTH SERVICE — The Service Finder can help you find dentists, orthodontists, paediatricians or speech pathologists near you.

Languages other than English

Parent Line is a free telephone counselling and support service for parents and carers. They offer parenting support for parents from culturally diverse backgrounds.

Aboriginal and/or Torres Strait Islander peoples

Visit Perth Children's Hospital website to learn about Keeping our Mob Healthy which has a collection of factsheets about children's health for Aboriginal and/or Torres Strait Islander people.