Why children suck their thumbs
Thumb sucking is a natural reflex for infants. It helps them feel secure, self-soothe, and fall asleep. In many cases, children outgrow the habit by age 3 or 4. However, if it continues beyond the preschool years, especially once permanent teeth start to push through, it can interfere with healthy oral development.
Not all thumb sucking causes dental issues. How frequently and how intensely a child sucks their thumb makes a difference. Passive suckers are less likely to have lasting effects, while aggressive suckers may face complications.
The oral health risks of prolonged thumb sucking
Once adult teeth begin to emerge (typically around age 6), ongoing thumb sucking can cause:
- Misaligned teeth – leading to overbite, underbite, or open bite.
- Changes in the roof of the mouth (palate) – potentially narrowing the jaw.
- Speech difficulties – such as lisping or trouble forming certain sounds.
- Protruding front teeth – which may require orthodontic treatment.
- Skin issues – including chapped or callused thumbs and fingernails.
In some cases, the upper and lower jaws can grow unevenly, requiring corrective care later in childhood.
When should you be concerned?
You should start monitoring thumb sucking habits around the time your child turns 4. If the habit continues past age five or begins affecting speech, teeth alignment, or bite, it’s best to consult a dentist.
Signs it may be time to act include:
- Teeth appear protruded.
- Changes in your child’s bite when chewing or closing their mouth.
- Redness or calluses on the thumb.
- Difficulty stopping, even with gentle encouragement.
Read more on Health Hub for more articles on dental and other health matters.
Read the article: What are “buck teeth” and how you can fix them
Thumb sucking as well as the use of pacifiers are one of the causes of “buck teeth.”
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A paediatric dentist can assess whether the habit is causing problems and offer advice on supporting your child in breaking it.
Helping your child stop thumb sucking
The best approach is gentle and encouraging, not punitive. Here are a few strategies that may help:
- Positive reinforcement – Praise and small rewards for not sucking.
- Distraction techniques – Offer a stuffed toy, blanket, or stress ball.
- Night-time solutions – Consider socks on hands or thumb guards if needed.
- Open conversations – Talk about how stopping will help their teeth grow strong.
- Dental support – Ask your dentist about behavioural techniques or dental devices.
It’s important to remain patient. Habits formed for comfort often take time and consistency to overcome.
Dummy (pacifier) vs thumb sucking:
Dummy sucking and thumb sucking both provide newborns with a natural, comforting reflex. Pros of using a dummy include the ability to control and wean the habit more easily, potential reduction in Sudden Infant Death Syndrome (SIDS) risk when used at nap and bedtime, and easier management of dental implications, provided it’s discontinued by age 3–4.
However, cons of dummy use include potential interference with early breastfeeding if introduced before 4–6 weeks, a higher likelihood of ear infections after 10 months, hygiene concerns, and possible dental misalignment if used beyond 4–5 years.
Thumb sucking, on the other hand, is always available and may be less disruptive to breastfeeding. But it’s harder to break, introduces more germs, and if continued past age 3–4, it can affect dental arch development, cause misaligned bites, open bite, speech issues or social anxiety.
In summary, both habits can affect oral development if prolonged, but a dummy tends to be easier to wean and control. Dentists and paediatric associations generally favour a pacifier over thumb sucking, primarily because it’s less likely to persist into the years when permanent teeth arrive and can be discontinued more effectively.
Early dental care makes a big difference
Routine dental check-ups allow your provider to monitor your child’s oral development and detect any issues early. Starting dental visits around age one helps establish trust and normalise oral health care as part of growing up.
Support your child’s healthy smile
Thumb sucking is normal in early childhood, but if it lingers, it’s worth taking steps to protect your child’s developing smile. Intercare’s team of dental professionals can provide supportive, judgment-free care and guidance.
Need help managing your child’s oral habits?
Book an appointment with a dentist today, and keep those smiles healthy.
