Thumb sucking is a natural infant reflex, shared by around 80% of young children in Australia.
And while the Australian Dental Association estimates that only around 15–20% of children continue thumb sucking after they turn five, this can mean that almost 1 in every 5 children is at risk of long-term dental problems.
As a trusted Parramatta orthodontist and provider of braces in Sydney, we know that prolonged thumb sucking should be taken seriously.
Early intervention can help break the habit, and reduce the need for more invasive treatments down the line.
There are steps you can take at home to help stop your child’s thumb sucking before it can become a more serious issue.
We’ll cover them in this guide, as well as how to spot if your child’s thumb sucking is affecting their mouth, so you can protect their smile for years to come.
What Is Thumb Sucking?
Thumb sucking is a common and natural behaviour for many infants and toddlers, and is widely believed to be a way of self-soothing.
Most children will grow out of their thumb-sucking habit by the time they’re around two to four years old.
They can do this by themselves, but some may require some additional support from parents and caregivers.
Is Thumb Sucking Bad for Teeth?
Thumb sucking in early childhood is unlikely to cause long-term problems.
However, as Ortho Co’s own Dr Doreen Ng notes in her 30-day guide to breaking the thumb sucking habit, if your child continues sucking their fingers past the age of four (or once their adult teeth have started to grow), it can have a significant impact on their dental development.
Some of the most common issues orthodontists treat in older children with a thumb-sucking habit include:
Changes to teeth and bite
If your child continues to suck their thumb, it can cause their adult teeth to grow in the wrong directions. This can look like:
- An overbite (when their upper front teeth push outwards to overlap their lower teeth)
- An open bite (their front top and bottom teeth can’t touch when they close their mouth)
Effects on jaw development
Prolonged thumb sucking can affect how your child’s jaw develops and lead to an upper jaw that is significantly narrower than their lower jaw.
This means that their upper and lower teeth can’t align properly, so their upper teeth will sit inside of their lower ones (known as a crossbite).
Impact on speech
Dental misalignments from sucking thumbs past infancy can change how your child’s speech develops.
This is usually due to tongue thrust (or reverse swallow) as the tongue is pushed forward while your child is speaking or swallowing, and can sound like:
- Trouble pronouncing “s” and “z” sounds (from an interdental or frontal lisp)
- Difficulty with consonant sounds that require precise tongue placement (like “t”, “d”, “n”, and “sh”)
When Should a Child Stop Sucking Their Thumb?
As a general recommendation, children should stop sucking their thumb when their adult teeth start to emerge, to reduce the risk of future complications.
However, every child’s mouth develops differently, and there are some other warning signs you can look out for to know when it’s time to stop their thumb sucking:
- Their teeth have shifted and aren’t lining up correctly
- Their speech is unclear, and they struggle to pronounce certain sounds
- Their tongue pushes forward when they’re speaking or swallowing
- Their mouth is open more often than it’s closed, even when it’s at rest
How to Stop Thumb Sucking
While many children will stop finger sucking on their own, there are others that may need a little extra support, and that’s okay.
If you’re trying to help your child break their habit, here are a few steps you can take at home:
Use Positive Reinforcement
By praising your child when they don’t suck their thumb, you create a positive and encouraging environment for them, and this can make them want to repeat the good behaviour.
Consider:
- Verbal praise and positive reinforcements
- Progress charts or calendars
- Consistent gentle reminders
- Small rewards or celebrations
This is typically more effective than punishing your child for sucking their thumb.
As the behaviour is most commonly a self-soothing one, negative feelings may increase their reliance.
Identify Thumb Sucking Triggers
Take note of when your child is sucking their thumb the most, and try to identify what’s causing your child to put their fingers in their mouth.
Common triggers include:
- Anxiety
- Stress
- Boredom
- Big emotions
- Fatigue
Offer Comfort and Healthy Alternatives
For some children, it can help just to know there’s an alternative to thumb sucking.
If you know they’re likely to start, or about to face one of their habit triggers, try redirecting them with:
- Their favourite toys or games
- Something to keep their hands busy
- A soothing hug or words of support
- Their comfort object
Create a Calming Bedtime Routine
Bedtime is often when children are looking to self-soothe, and fatigue is a common trigger for thumb sucking.
This means that having a stressful nighttime routine, from difficulty falling asleep to trouble staying asleep, is likely to make your child’s thumb sucking worse.
You can help them by establishing a safe and relaxing nighttime routine and reducing the need for their comfort behaviour:
- Read them a book before bed
- Play soft, calming music
- Give them their favourite comfort toy or blanket
- Remove screens at least an hour before bed
- Be consistent (when possible)
Guard Their Thumbs
Some children will benefit from having their thumbs and fingers covered, especially while they’re asleep and not consciously aware of what they’re doing with their hands.
This can be as simple as putting a pair of comfortable mittens or gloves on before bed as a DIY thumb-sucking guard.
There are also commercial thumb guards available.
These are plastic or fabric guards specifically designed to be gentle, effective, and non-restrictive, providing a physical barrier between your child’s teeth and skin without ruining their sleep.
Want a step-by-step plan? Download Dr Doreen Ng’s free 30-day guide to breaking the thumb-sucking habit.
When Should You See an Orthodontist About Thumb Sucking?
Every case is different, and your child’s treatment will depend on their specific dental needs.
But if you’ve tried at-home solutions and your child is still sucking their thumb, or they have stopped but you can see a difference in their teeth, orthodontic treatment may be necessary.
At Ortho Co, we know that early intervention is key, and it’s the best way to stop your child’s thumb sucking from developing into a more serious issue that requires more complex treatment.
Our experienced kids orthodontists in Sydney can help assess your child’s oral condition and outline a treatment plan specifically designed for their smile.
Whether that’s braces to realign their teeth or a palate expander to correct a crossbite from thumb sucking, we’re here to support them at every stage of their development.
To learn how we can help protect your child’s smile now and in the future, you can call us or book an appointment with our team today.
Not ready to book yet?
Sign up for Dr Ng’s free 30-day guide to breaking the thumb-sucking habit.
