It might look adorable, but how is Prince Louis’ thumb sucking going to impact him down the track?

He's the baby royal we all adore, and when images emerged of his devoted mum, the Duchess of Cambridge stopping little Prince Louis from sucking his thumb at the christening of baby Archie, we all sighed a collective "awwww".

It's adorable, right? A cherub-faced tot taking comfort from their own thumb. It's so innocent and sweet, but is it going to cause the little Prince problems with his teeth later in life?

According to Dr John Brabant from Evolve Orthodontics – Invisalign Centre thumb sucking is a normal habit up until 4-5 years of age and shouldn't cause too many problems if nipped in the bud before that.

"Parents should not discourage it up until this point," he says.

"Avoid nagging and shaming the child as these are destructive experiences for both the child and their parents.

"A child's psychological health is just as important as the child's dental health," says Dr John Brabant.

"A lot of children are thumb sucking for need of security and it is almost impossible for them to stop unless they want to do so."

Having said that, long term thumb sucking can have a negative impact on your child's dental health too.

What impact can thumb sucking have on Prince Louis’ bite as he moves into adolescence?

According to Dr John Brabant, thumb sucking is considered normal up until four to six years old. However, there can be dental problems for thumb suckers moving into adolescence.

He says:

• The severity of the effect of thumb sucking on the teeth depends on the intensity and frequency.
• Persistent sucking continued during the time that the teeth begin erupt can result in pushing the upper teeth forward, the lower teeth backward, and creating an open bite where the front and bottom teeth do no connect.
• Vigorous sucking can also lead to changes in the upper palate and jaw.
• Thumb sucking can affect the baby teeth, but these teeth will fall out and the child's bite can correct itself if the thumb is removed.
• Research shows that many thumb suckers were never given a pacifier. This makes a case for pacifiers, as it is much easier to take a dummy away than to break the habit of thumb sucking.
• If the habit is continued into adolescence, the front teeth of the child can start to stick out and the bottom teeth will be forced inwards and start to crowd. Thumb sucking may mean that the child's top and bottom teeth don't come together. The child may also have problems with their speech, as the tongue has problems moving between the teeth.

What are the long term effects of thumb sucking?

While it's true that thumb sucking is not really a major problem unless it continues after six years of age, there are still changes that might occur if Prince Louis continues to suck his thumb long term.

Dr John Brabant, suggests the effects of long-term thumb sucking are:

• The longer that thumb sucking goes on and the more intense the sucking is, the more the child's jaw changes.
• Teeth move and the upper jaw is pushed forward.
• With the teeth not in contact at the back of the child's jaw, a narrow palate can result, which changes the whole bite. Once the bite is out of position, it needs correction.
• If the thumb sucking is stopped early enough, the teeth can experience spontaneous correction.

What can parents do to stop their kids from thumb sucking?

"Parents can appeal to the child's sense of what is in their best interest," suggests Dr John Brabant.

"An effective technique I have found is showing the child photos of their mouth.

"Take your child to an orthodontist to show them pictures of severe cases of before and after treatment of thumb suckers. This will give the child an idea of what is happening in their mouth, how to rectify the changes, and give them personal accountability for working towards the end result."

WATCH: Prince Louis Christening below …