A dummy in the first year or two is rarely a dental worry. What shapes a child's bite is how many months and years the sucking habit continues, so the useful question for parents is less "should we use one?" and more "when do we stop?". For most families, working towards giving it up around the third birthday keeps the risk to the teeth low.
Below we cover what long dummy use can do to a growing mouth, how it compares with thumb sucking, and ways to wean that tend to cause fewer tears.
The longer the habit, the more the bite can change
A dummy sits between the front teeth for hours at a time, and the sucking action pulls the cheeks inwards against the upper back teeth. In a mouth that is still growing, that steady pressure can gradually alter how the teeth meet. Better Health Channel, the Victorian Government health site, notes that sucking a dummy, thumb or finger can change the teeth and jaws if it becomes a long-term habit.
Two changes come up most often:
- Open bite at the front. The top and bottom front teeth no longer meet when the back teeth are together, leaving a gap where the dummy usually sits.
- Posterior crossbite. The upper jaw becomes narrower, so some upper back teeth bite inside the lower ones. Sometimes the jaw shifts to one side to make the teeth fit.
A 2016 systematic review in the Journal of the American Dental Association (Doğramacı and Rossi-Fedele), drawing on 15 studies, confirmed that non-nutritive sucking is linked with these bite problems and that a longer habit carries a higher risk. It also found that dummy users were more likely than thumb or finger suckers to develop a posterior crossbite in the baby teeth.
Not every change fixes itself
Parents are often told that the teeth will straighten out once the dummy goes. That can be true for a mild open bite at the front, which may improve after the habit stops. It is less reliable for crossbites. In a study that followed 372 children from birth (Warren and Bishara, American Journal of Orthodontics and Dentofacial Orthopedics, 2002), some changes, including posterior crossbite and increased overjet, persisted well after the dummy or thumb habit had ended.
So stopping earlier gives the bite the best chance, and a crossbite that is still present after the habit has gone is worth having checked.
Dummy or thumb
Neither is ideal if it carries on past the preschool years, but a dummy has one clear advantage: you can take it away. A thumb is always available, which is why thumb habits often last longer. As noted above, the two habits also tend to affect the bite in slightly different ways. If your child is a thumb sucker, our article on thumb sucking and the teeth looks at that habit in detail.
Weaning without a battle
Better Health Channel reports that most children give up sucking habits somewhere between two and four, and that a habit continuing past four can be harder to break. Gradual changes usually go better than taking the dummy away overnight, which the same source warns can lead to a different oral habit taking its place.
Approaches that many families find work:
- Keep the dummy for sleep only, then drop it from daytime naps once those naps stop.
- Offer something else for comfort during the day, such as a cuddle, a favourite toy or a change of activity.
- Give an older toddler a few days' notice, and make the final handover an event: a swap for a toy they choose, a "dummy fairy" visit or a birthday.
- Pick a settled week rather than a time of illness, travel, a new sibling or starting childcare.
- Stay calm and consistent. The first few nights are usually the hardest, and praise works better than pressure.
Keep the dummy plain
Never dip a dummy in honey, jam, syrup or anything sweet to help a baby settle. It coats newly erupted teeth in sugar and can cause severe decay very quickly. The same goes for sweet drinks in a bottle at bedtime, a pattern we explain in our article on baby bottle tooth decay.
When to have your child's bite checked
Book a visit if your child is past three and still relies heavily on the dummy, if you can see a gap between the front teeth when they bite together, or if the lower jaw seems to slide to one side as they close. Our dentists and oral health therapists see young children and can tell you whether the bite is likely to settle or needs keeping an eye on. If your child has not been to the dentist yet, our guide to a child's first dental visit explains what happens.
What parents ask us
Is a dummy harmful in the first year?
Not for the teeth. Dummies are a common and useful way to soothe a baby. Concerns about the bite relate to use that continues for years.
Does it matter how often my toddler uses it?
The research mostly measures how long the habit lasts, and longer use is consistently linked with more bite changes. Cutting back to sleep time is still a sensible first step towards stopping altogether.
My child stopped at four. Should I worry?
Not necessarily. Many bites are fine, but it is worth asking your dentist or OHT to check for a crossbite at the next visit, since that is the change least likely to correct by itself.
Getting help
If you have questions about your toddler's bite, or would like ideas for weaning, the team at Lumi Dental is happy to help. You can see our current offers, or read more about teething and how to clean baby and toddler teeth.
This article is general information and not a substitute for an individual dental assessment.
