Why do babies suck their thumb or use a dummy?
Comfort sucking is a natural habit for many babies — a thumb, fingers or a dummy can help them settle, sleep or soothe during teething.
SA Dental describes thumb or finger sucking as a natural habit in babies. The Australian Dental Association lists a dummy among options some families use when a tooth is coming through (teeth.org.au). The habit itself is common; what matters for teeth is how long it continues, how intense it is, and dummy hygiene once teeth are present.
When do most children stop?
Most children stop thumb-sucking between about two and four years of age.
SA Dental states that thumb or finger sucking usually stops between two and four, and that dummies can affect the teeth in a similar way, though dummy habits are often phased out sooner than thumb habits (SA Dental). Queensland Health’s Happy Teeth factsheet says thumbsucking or dummy use is little cause for lasting concern before permanent teeth appear, and that habits that continue after permanent teeth start may push teeth and jaws out of alignment (Queensland Government).
Timing varies. Some children stop earlier; others need more support in the preschool years. A dental check can help you decide whether the habit is still mostly a comfort issue or whether the bite needs a closer look.
How should I look after a dummy for my child’s teeth?
Keep dummies clean, undamaged and free of sugary flavours — and do not clean them in an adult’s mouth.
Australian guidance is consistent on the main hygiene points:
- No honey, jam or other sweet dips. The ADA and healthdirect both warn that a dummy dipped in honey or other sweet substances can raise the chance of tooth decay once teeth are present (teeth.org.au). Queensland Health likewise says not to add flavouring (Queensland Government).
- Do not suck the dummy yourself. Queensland Health advises against cleaning a child’s dummy in your own mouth, because bacteria can transfer from adult to child. Wash a dropped dummy under running water, or use a sterilising solution when you have one. Carry a spare when you can (Queensland Government).
- Check for damage and do not share. Inspect dummies for rips or tears and replace them if damaged. Children should not share a dummy (Queensland Government).
These steps protect teeth from sugar and reduce germ transfer. They do not replace brushing once teeth appear — see how to look after your child’s teeth for age-by-age cleaning.
When might sucking habits affect the teeth or bite?
A prolonged sucking habit — especially after permanent teeth begin to appear, often around six or seven — may affect tooth position, how the front teeth meet, or jaw growth in some children.
SA Dental notes that dental problems related to jaw growth and tooth position can occur if thumb, finger or dummy sucking continues after permanent teeth come through, and that some speech sounds can also be affected if front teeth are pushed forward (SA Dental). Healthdirect states that the bite can be affected if thumb-sucking continues as adult teeth appear (healthdirect). The ADA also asks about thumb, finger or dummy habits at early visits because those behaviours can affect tooth health and mouth development (teeth.org.au).
Not every child with a habit develops bite changes. Intensity, hours per day and how long the habit lasts all matter. This article does not promise that stopping a habit will straighten teeth, or predict any particular treatment pathway. Only an examination can assess your child. If something is outside the scope of a general dental practice, the team will talk with you about next steps, including referral where appropriate.
How can I help my child stop — and when to ask AMK?
SA Dental encourages families to help children stop thumb, finger or dummy sucking around two to four years, and notes that children usually need to want to stop — it may take several attempts (SA Dental).
Queensland Health suggestions include limiting a dummy to sleep times, removing it once the child is asleep, discouraging walking around with a thumb or dummy in the mouth, and, around age four, agreeing a clear stop date (for example a birthday) while gradually reducing use (Queensland Government). Praise for progress often works better than punishment. Avoid coating a thumb or dummy with unpleasant tastes unless a dentist or doctor has advised that approach for your child.
When to ask AMK: book a visit if the habit continues into the school years, if you notice the front teeth not meeting as expected, or if you want tailored advice on reducing the habit. At AMK Dental Clinic in Mortlake, children’s dentistry visits can include a look at growth and habits — similar questions come up at a first dental visit. Call (02) 9739 6525 or use our contact page to book.
Book a children’s visit in Mortlake
AMK Dental Clinic offers children’s dentistry at Shop 3, 46 Tennyson Road, Mortlake NSW 2137, for families from Mortlake and nearby suburbs including Breakfast Point, Cabarita and Concord. To book, call (02) 9739 6525 or use our contact page.
This article is general information only. It does not replace advice from your doctor or dentist about your child.
This article is general information only and is not a substitute for advice about your own situation. Please speak with a dentist about your needs.
Common questions
Is thumb-sucking or a dummy bad for baby teeth?
Comfort sucking is common and often stops between about two and four years of age. Queensland Health notes little lasting concern before permanent teeth appear, while SA Dental and healthdirect say prolonged habits after permanent teeth start (often around six or seven) may affect tooth position or bite. Not every child with a habit develops bite changes. Ask a dentist if you are unsure about your child.
Should I clean my child's dummy in my own mouth?
No. Queensland Health advises against sucking your child's dummy, because that can transfer bacteria from your mouth to theirs. Wash a dropped dummy under running water, or use a sterilising solution when you have one. Never dip a dummy in honey, jam or other sweet flavours — that raises the chance of tooth decay once teeth are present. Check dummies for tears and replace damaged ones.
When should I talk to AMK about a sucking habit?
Book a children's visit if the habit continues past the preschool years, if you notice changes in how the front teeth meet, or if you want advice on reducing dummy or thumb use. At AMK Dental Clinic in Mortlake a general dentist can check development and discuss options suited to your child. Call (02) 9739 6525 or use our contact page. Care outside general practice scope is discussed with you, including referral if needed.