If your toddler likes to suck his thumb or his dummy, then at one time or another you have most likely asked yourself if he really needs to stop doing it, or if it’s something natural that he will just outgrow. This is actually quite a common question for us as a dentist in Diggers Rest to get asked by parents of toddlers who begin to notice that their child is getting real teeth for the first time. The truth is that in most cases, it’s perfectly fine. However, there does come a point when it becomes important, and knowing what that point is could help you avoid many worrying moments.
Why Babies Do This in the First Place
Sucking is one of the most natural reflexes a baby has. It’s soothing, it helps them settle, and in the very early months, it genuinely does no harm at all. Whether it’s a thumb, a finger, or a dummy, this is completely normal newborn and infant behaviour, and there’s no reason to discourage it during this stage. In fact, for very young babies, a dummy can even come with some benefits, like helping to settle them for sleep.
When It Starts to Matter
The key factor isn’t really the habit itself, it’s how long it sticks around. Most children naturally drop thumb sucking or dummy use somewhere between two and four years old, often without any real intervention needed from parents at all. This age range tends to line up with when a toddler’s coping skills and sense of independence are developing in other ways too, so they simply don’t need the habit as much anymore.
The real risk window opens once the habit continues well past this stage, particularly once a child reaches three or four and their permanent teeth are starting to develop underneath their baby teeth. Before that point, most dental changes caused by sucking habits are considered reversible once the habit stops. After that point, things become a bit more complicated.
What Prolonged Sucking Can Actually Do to Teeth
When a child sucks intensely on a thumb or dummy over a long period, it puts consistent pressure on the front teeth and the roof of the mouth. Over time, this pressure can start to shift how things are developing. A few changes are fairly common when a habit persists too long:
Front teeth can be pushed forward, sometimes described as “buck teeth,” which can affect both appearance and how comfortably a child bites and chews. An open bite can develop, where the front teeth don’t actually touch when the mouth is closed. A crossbite is also possible, where the upper teeth end up sitting inside the lower teeth rather than outside them. In more prolonged cases, the shape of the roof of the mouth and even general facial growth can be affected.
Some research has found early signs of these changes showing up as early as 18 to 24 months in children with particularly frequent or intense habits, though for most kids, there’s a much longer runway before any of this becomes a genuine concern.
Thumb Sucking vs Dummies: Does It Matter Which One?
Both habits affect the mouth in broadly similar ways, so it’s less about which one is “worse” and more about how long either one continues. That said, there’s one practical difference worth knowing. A dummy can simply be taken away and phased out gradually, which gives parents a reasonably straightforward path to ending the habit. A thumb, on the other hand, is always available, which tends to make it a harder habit to break, especially once a child is old enough to seek it out for comfort on their own, including overnight when nobody’s there to gently discourage it.
What You Can Actually Do About It
If your child is still within that two to four age range, there’s often no need to intervene at all. Most children do grow out of it naturally as other comfort habits and coping strategies develop. If the habit is continuing past four, or you’re noticing your child reaching for it constantly rather than just occasionally, a few gentle approaches tend to work well. Praise and small rewards for stretches without the habit can help build motivation, particularly once a child is old enough to understand the idea of working toward something. Identifying when the habit shows up most, like at bedtime or when they’re anxious, and addressing that trigger directly, often works better than trying to stop the behaviour cold. Involving an older child in choosing how they want to stop, rather than it being something done to them, also tends to get better results.
When It’s Time to Bring In Your Dentist
If the habit is still going strong by the time your child turns four, that’s generally a reasonable point to raise it at their next check-up rather than waiting to see what happens. A dentist can take a proper look at how their teeth and bite are developing, let you know whether there are early signs of the changes mentioned above, and help guide a plan if the habit needs a bit more structured support to break. In some cases, a simple chat directly with a dentist, explaining in child-friendly terms what can happen to their teeth, works better coming from someone other than mum or dad.
Conclusion
Thumb sucking and dummy use are a completely normal part of early childhood, and for the vast majority of kids, they cause no lasting issues whatsoever. The main thing worth keeping an eye on is simply how long the habit continues, particularly once your child approaches the age where permanent teeth start forming underneath their baby teeth. If you’re ever unsure whether your child’s habit is something to actively address, it’s always worth raising it at their next regular check-up rather than guessing on your own.
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