Thumb suckers: breaking the habit

Thumb sucking can be a cute comfort, but when should parents consider pulling the plug? Dr Mo Al-Dujaili explains the effects on teeth and what can be done about it.

Everything about a baby or a toddler changes, and it changes very rapidly. The first two years of life show the highest growth velocity, with key tissues within the body growing, developing and continuing to remodel. We are certainly born already programmed to become who we will become … our height, the colour of our hair and how we look are some characteristics that are predetermined. That said, there are some traits or characteristics that can be influenced or changed by the environment around us. An example of this is the density of our bones – spend more time lifting and performing manual labour, and chances are, you’ll end up with denser bones. Spend time at the gym and it is highly likely that you will build strength and muscle size. So what does all this have to do with your child’s teeth?

This is a story about jaw growth and teeth alignment, and the harmful effects that certain habits can have on them. A good bite for the teeth relies on the upper and lower jaws growing in synchrony, which provides a foundation for the teeth to align and the muscles to function properly. The result – a beautiful smile. Anything that disrupts this balance when a child is growing can have prominent effects. Whether it is a muscle imbalance or something being introduced into the mouth, be it a pencil, pacifier, thumb/fingers or a child biting their fingernails, there will be the potential to disrupt this harmony and balance of jaw growth if these are used for very long periods of time. 

Thumb suckers unite
If your child is sucking their thumb, you are not alone! Thumb- or finger-sucking habits are the most common habits that orthodontists in New Zealand would see on a daily basis. They are prevalent in the two- to five-year age group and can be a normal part of growth and development. The habit acts to physiologically mimic suckling, which in turn provides a child with psychological comfort, relief and reassurance when they are doing it, and it is sometimes a way for children to deal with stress. Problems arise when these habits continue as the permanent adult teeth begin to erupt (around the age of six years). The changes that occur when the child is beyond six years of age seem to be significant and can affect the growth of the jaws and the alignment of the teeth. Further, the duration, position of the finger or thumb, and degree of pressure or force of sucking can also have a significant negative effect on the position of the teeth. The good news is that thumb- or finger-sucking habits seem to reduce dramatically when children start school, as most tend to be nervous or worried about what their peers might think. 

Common presentations of thumb or finger sucking include:

⭐ ‘Buck’ and spaced upper teeth

⭐ Lower teeth that are tipped in towards the tongue

⭐ Narrow upper jaw with the upper teeth sometimes biting on the inside of the lower teeth

⭐  Upper and lower front teeth that do not touch at the front

⭐  Improper speech

⭐ Abnormal tongue position and posture can develop

Breaking the habit
The key to stopping a habit is in the approach taken and explanations given to the child. Most thumb sucking can be eliminated by teaching a child how to unlearn the habit – this is why having a child wanting to stop is a key to success. It is also important for the habit not to be stopped abruptly, as this can be harmful to normal emotional development.

There are numerous aids available over the counter to try to encourage young ones to stop a sucking habit, with varying success rates. For example, a readily available aid is the guard around the thumb, where a small splint with Velcro is placed around the offending thumb. The problem with this product is that when it is used without proper explanation to a child, the child simply learns to take it off and continue with the same habit.

Some helpful tips and suggestions:
⭐ Current research suggests stopping habits around the age of six, as any changes that have occurred to jaw growth and teeth alignment can still spontaneously self-correct without the need for orthodontic treatment. A thumb- or finger-sucking habit in the earlier years does not seem to cause significant effects, although in the younger years, it might be a good time to sow the seed by talking to your child and encouraging them to stop.

⭐ Explain to the child and show them what the habit is doing or can do to their teeth. Some pictures from the internet of ‘buck’ teeth can illustrate to a child what will happen to their beautiful smile if they continue to thumb/finger suck.

⭐ A child needs only a gentle reminder. For example, if they are sucking their thumb while watching TV, a little tap on their finger will do the trick.

⭐ Children in general respond much better to a reward system rather than punishment. An example of this could be a simple star chart on the fridge door – every day/night without sucking their thumb results in a star. Obtaining seven stars a week results in a small reward. Within a few weeks, we frequently see that a learned habit disappears.

⭐ Prevention of the progression of these habits is crucial. A great idea for a preschool-aged child is to attempt to substitute a thumb or finger that is being sucked with a dummy, at bedtime only. This is particularly helpful, as children going to school around the age of five will not want to be sucking a dummy in front of their school friends, minimising the duration of sucking that is occurring.

⭐ In some trickier situations, we suggest swapping the habit to a less significant one. For example, teaching a child to fidget a pen between his fingers or to twirl their hair.

These suggestions relate to behaviour modification techniques that aim to unlearn a habit. There are further ways specialist orthodontists can help in eliminating sucking habits, most of which involve small appliances that are either fixed or removable (in the form of a plate). These have varying success rates, reflecting children’s different presentations and personalities.

The success of both behaviour modification techniques and appliance therapy options is only achieved when the children themselves realise the significance of the problem, and what the habit is causing. Only when children understand the problem is it possible to begin to correct it – making it much easier to fix.

Armed with the above information, you should be able to help your child eliminate their habit promptly. If you are still having difficulties correcting a thumb- or finger-sucking habit, or you are worried about anything to do with how their teeth alignment looks or their jaw growth and bite issues, I recommend you consult a specialist orthodontist for individualised advice.

Dr Mo Al-Dujaili is a locally trained specialist orthodontist with a special focus on preventative and early interceptive orthodontic treatment for children. He works in private orthodontic specialist practice servicing the Auckland area. See more about Mo at www.shakespeareortho.co.nz.