What is thumb sucking?

Thumb sucking in infants is common, often starting before birth. In most cases, babies and toddlers stop sucking their thumb by themselves.

Thumb sucking may cause problems with children's developing teeth and jaws if it continues as they get older.

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 to 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

Most toddlers naturally stop sucking their thumb between 2 and 4 years old. By the age of 8 years, less than 1 in 20 children sucks their thumb.

Is thumb sucking bad for teeth?

Many children who suck their thumb do not have problems with their teeth. Whether thumb sucking causes problems may depend on:

• your child's growth and development
• how often they suck their thumb
• the angle of their thumb in their mouth
• how hard they suck

Thumb sucking may become a problem if your child still sucks their thumb when their permanent teeth (adult teeth) start to appear.

Possible problems caused by thumb sucking can include:

• your child's upper jaw being pushed out further from their face
• upper front teeth being pushed upwards and out, commonly called an overbite'
• tipped back lower front teeth
• a gap between your child's upper and lower teeth
• not being able to bite the front teeth together
• the palate (roof of the mouth) becoming pushed up and narrow

Your child's speech and the position of their tongue in their mouth may also be affected.

How can I stop my child sucking their thumb?

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

Positive reinforcement is the best way to help your child to stop thumb sucking. Support, encouragement and reminders are important.

Noticing when they haven't been sucking their thumb, and pointing out how 'grown up' they are, is a way to be positive. It also becomes easier when the child realises that they want to stop sucking their thumb.

Self-help tips

Here are some strategies for helping your child to stop thumb sucking.

• Reminders — gently remind your child to take their thumb out of their mouth. When they do, offer hugs and praise. You may also like to create a private signal if you are with other people, to prevent your child being embarrassed about the reminder.
• Record their progress — on a calendar, with rewards or stickers when they reduce or stop the behaviour.
• Barriers — at night, use gloves or an adhesive bandage on their thumb as a barrier.

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. Don't nag them in a negative way, as this can make your child defensive.

These strategies may also 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), discuss it with a:

• dentist
• dental practitioner
• orthodontist

It's best to wait until this age because your child needs to be old enough to understand and accept responsibility to break the habit.

Resources and support

If you're worried or feel that you need help to stop your child sucking their thumb, you may like to contact:

• your local dentist or orthodontist
• your maternal child health nurse

You can also find information at Orthodontics Australia.