When should my child stop sucking their thumb and how can I stop them?

From a dental point of view, in particular the Canadian Academy of Pediatric Dentists, we recommend that a child stops the habit of sucking their thumb by age three. We find that if a child is able to stop that habit by age three there is no lasting affects to the dentition.

What affects can happen from sucking the thumb? One of things that can happen is the front teeth are pushed forward. Another thing that can happen, which depends upon the intensity which the child is sucking, and also the frequency would be the whole arch width can be narrowed. So generally the top teeth should be the lid and the bottom teeth would be the box. In children who suck their thumb, the top teeth end up not fitting over top of the bottom teeth; they become narrower from the thumb being in the roof of the mouth so much. Another thing that can happen besides the teeth being pushed forward and the back teeth being pushed inwards, is when your child bites, the teeth don’t come together. They are biting on their back teeth but the front teeth are open, so it actually pushes the front teeth up also, forward and up. This can have a major effect on: one, the child’s speech; two, their ability to chew and bite or incise with their front teeth because if they can’t bite, they can’t chew their food; three, they become at increased risk for trauma or bumping their front teeth because they are pushed out. It’s very important that this thumb habit ideally never starts but if it does that it is weaned by age three.

From a speech therapist point of view, they would even promote stopping the thumb sucking earlier because they find it delays children’s speech if they are sucking their thumb all the time. The same goes for a pacifier habit. If the child has something in their mouth they are less likely to converse with their peers and actually explore what their voice sounds like and using words.

What are some methods to try to help your child stop? The main thing is having a child who wants to stop. Positive reinforcement goes a long way for children who really aren’t interested in stopping their habit, so catching them not sucking their thumb and for instance, creating a rewards chart or some type of sticker system, so that ‘hey we caught you not sucking your thumb’, you get a sticker on your calendar and at first it may be, ‘you got through the whole morning without sucking your thumb’ and we get a slight reward and eventually it would be ‘you went the whole day, you went two days, and you went a week’ and you start to find your child remind you or let you know – ‘hey I’m not sucking my thumb’ and it can be a real fun experience.

For the tougher children there are products out there. One is called nail biter and it is a clear paint that’s painted on the nail, which was initially to curb nail biting but it can serve as a reminder when the child puts their thumb in their mouth and it doesn’t taste good so they take it out. Ideally your child wouldn’t know why they have this polish on their hand because that can be stressful to them. Make it a fun thing that you’re painting their nails but in actual fact you’re using it as a behaviour technique.