Thumb or dummy: when does it start to affect your child's teeth?

Is it normal, or should I worry?

In the early years it is normal, and there is no need to worry. And most children cut down or stop on their own somewhere between about two and four.

For most children it is a way of settling themselves: when they are tired, bored, sleepy or upset. It is not a sign of a problem, and it does not mean they are spoilt.

And the effect on the teeth depends on three things:

• How many years it lasts. Sucking while they still have their baby teeth is not the same as sucking after the adult front teeth start coming through, at roughly six or seven.
• How many hours a day. A short suck before sleep is not the same as a thumb in the mouth for most of the day and night.
• How hard. Some children rest a thumb in the mouth gently; others suck so hard you can hear it, or the thumb comes out red and chapped.

What can sucking do if it goes on?

If the habit carries on, especially once the adult front teeth start coming through, the steady pressure can change things in the teeth and the jaw. It might, but it doesn't have to, and not every child who sucks a thumb ends up with any of this:

• A gap at the front when they bite. When they close, the upper and lower front teeth do not meet, and a space stays between them where the thumb used to sit.
• Upper front teeth tipped forward. The upper front teeth lean outwards, and sometimes gaps open up between them, though gaps have many causes besides sucking: Gaps and crowded teeth in children.
• A narrower roof of the mouth. While sucking, the cheeks press on the sides of the upper jaw and the tongue sits low. So the jaw can become narrower, and the upper teeth do not close properly over the lower ones, on one side or on both.

The good news is that your child's teeth and jaw are still growing. If the habit eases early, while they still have their baby teeth, many of these changes can improve on their own over time. But if the upper jaw has become narrower, or the jaw slides to one side as they close, that usually does not settle on its own, so it needs a look. And the more it eases before the adult front teeth come through, the better the chance their teeth have of settling into their natural place.

How to help your child stop, calmly

The aim is not for them to stop tomorrow; it is for them to stop and feel all right about it. These steps are for an older child who has kept the habit, from about three, not for a baby. And every day the habit eases gives their teeth and jaw a little more room to settle.

1. 1

   Praise them when they manage itWhen you notice their hand out of their mouth, especially at the times they used to suck, tell them you have noticed. Praise usually works better than telling them off.

2. 2

   Learn when they suckMost children suck at familiar times: when they are bored or tired, in front of a screen, before sleep, or when they are upset. Once you know the moment, you know where to help.

3. 3

   Swap the habit in that momentWhen they are bored, keep their hands busy: a toy, crayons, or a big soft ball to squeeze. At bedtime, a cuddle and a story, or a soft toy to hold. And if they suck in their sleep, gently take the thumb out once they have dropped off, without waking them.

4. 4

   Make them your partnerTalk to them, in words that suit their age, about why you want to cut down together, and agree on a quiet signal between you instead of a reminder out loud. A star chart on the wall for every day or night they manage gives them something to be proud of.

5. 5

   No punishment, no shamingDon't put anything bitter on their thumb yourselves, don't shout, and don't comment in front of other people or their brothers and sisters. That only makes them more anxious, and anxiety in particular is one of the things that sends the thumb back into the mouth.

6. 6

   Pick your moment, and be patientIf something big is changing in their life, such as a new baby, starting nursery or moving house, put it off until they have settled. And if they slip back a few times, that is normal: start again, without counting it as a failure.

Dummy or thumb?

If either goes on for long, the effect on the teeth is much the same, and the same rule applies. The big difference comes down to one thing: a dummy is easier to take away. It isn't part of them, so you can cut it down and take it away when you decide, while the thumb is always with them.

A dummy dipped in something sweet so they will take it harms the teeth in another way, through decay, and that is explained here: Baby bottle tooth decay: how to protect your child’s teeth.

When the time comes to take it away, once they have outgrown it, some children switch to their thumb instead. So it is easier to take it away gently, with something else to settle them at bedtime: a cuddle, a story or a quiet song.

When should the doctor take a look?

You do not have to wait for the habit to leave a mark before you ask. But there are two times when an examination makes a difference:

• The habit is still there, and the adult front teeth have started coming through. That is at roughly six or seven. Checking at this point gives you more time to act.
• You have started to see an effect on the bite. The front teeth do not meet when they bite, or the upper ones stick out, or their jaw slides to one side as they close.

At the examination the teeth, the bite and the width of the jaw are checked, and you are asked about the habit: when, and how much. You'll find out whether the effect could improve if the habit eases, or whether it needs following up. And watching how the jaws grow and how the bite develops is part of children's dentistry at the clinic.

Is there an appliance that helps them stop?

There are small appliances that sit in the mouth and make sucking harder, so they remind your child and help them break the habit. They are not the first step. The doctor decides on one after an examination, and if one is needed, you'll be told why. One is usually fitted when the habit carries on after the adult front teeth start coming through, and starts to affect the teeth or the bite. They also work better when the child wants to stop. And if the effect needs more than breaking the habit, an early orthodontic check tells you what the next step is, and when: Braces for children and teenagers.

Questions people ask