Thumb sucking is incredibly common among young children. 90% of infants regularly suck their thumb or fingers during the first year of their life. It is an instinctive reflex that can help soothe a child during periods of distress or restlessness. However regular thumb sucking, even only during the first couple of years of your child’s life, can have significant negative impacts on the development of an infant’s oral health.

This potential damage to their oral health, combined with how easy this habit is formed, means that thumb sucking should be discouraged as early as possible, says London based dentist Boryana Nikolova. There are several ways that early-years thumb sucking can damage your child’s oral health. Let’s go through them now.

Thumb sucking can cause protruding front teeth

The most well known negative effect of thumb sucking is that it can cause your front incisors to protrude over your lips. This phenomenon, also known as an overbite, or “buck teeth” is often considered cosmetically unappealing, and can lead to teasing from other children. As your child gets older, they will often want orthodontic treatment to correct this overbite. More importantly to your child’s oral health, teeth that protrude over your lips are more likely to suffer from chips or cracks. This is because lips act as shock absorbers to physical trauma that would otherwise damage teeth. Teeth with tiny cracks and chips are very vulnerable to developing toothache as bacteria can make its way inside the tooth and cause painful infection. This could result in many unwanted trips to the dentist for your child.

Thumb sucking causes protruding teeth as your child’s thumb pushes against the part of their gums where the teeth emerge. If this happens regularly, then it will alter the path that the teeth take when they grow. Given that the thumb presses upwards from behind where the teeth erupt, this will naturally push the front teeth forward. Adult teeth often follow the same pattern of growth as your child’s milk teeth, meaning that without orthodontic treatment, your child’s teeth may well remain producing into adulthood.

Encouraging mouth breathing

As thumb sucking forces your child’s mouth open during rest, it habituates breathing in through the mouth rather than through the nose. As habits that begin early are particularly hard to shake off, mouth breathing can persist through adulthood. For this reason, we recommend you discourage your child from thumb sucking as early as possible. Breathing in through the mouth rather than through the nose is harmful to oral health for a couple of reason. Firstly, breathing in air through the mouth increases the number of harmful bacteria that come into contact with your teeth. This increases the likelihood of bacteria getting inside the cavity of your teeth via tiny holes or cracks caused by decay. This type of infection is the main cause of toothache.

Furthermore, breathing through the mouth will stain your teeth.
This means that no matter how diligent your child is about brushing, they are always playing catch up when it comes to keeping their teeth white. The dehydrating effects on teeth of breathing through the mouth also makes teeth more vulnerable to cavities as saliva offers a protective anti-bacterial layer for your teeth. In people who breathe through the mouth, this protective layer is dried away.

Your child is more likely to develop mouth ulcers

Mouth ulcers are already very common in children as their immune system is still developing. Thumb sucking greatly increases your child’s chances of developing regular mouth ulcers as they often scratch the delicate soft palette of their mouths with their thumb or fingers. Although this is not a hugely damaging problem in itself, mouth ulcers can make children more resistant to tooth brushing, as it causes them pain to do so. This can create a habituated aversion to tooth brushing that can, in turn, leads to poorer oral health habits in the future.

So how can I stop my child from sucking their thumb?

Given that thumb sucking can be detrimental to your child’s oral health in a number of ways, the next question is naturally: “how can I stop my child from sucking their thumb”. Given that thumb sucking ought to be discouraged during infancy, you cannot simply tell a child not to suck their thumb. Rather, you need to show them that thumb sucking simply is not something that they can do. This is simply done by removing their thumb or fingers from their mouth every time they start to suck.

In doing this, you will prevent the habit of thumb or finger sucking before it is even formed. This will mean that the difficult process of trying to wean a young child off thumb sucking never has to happen. Of course you cannot stop your child from sucking their thumb or fingers 24 hours a day, however significantly reducing the amount they suck their thumb when you are with them should, in most cases, stop the habit from forming.

Boryana Nikolova is the owner and Principal Dentist of 92 Dental in London, England. She is passionate about preventative dentistry and children’s oral health.

Dr Boryana Nikolova

Dentist, 92 Dental