5 Ways Prolonged Thumb Sucking Can Affect Oral Development

Thumb sucking is a very common habit among children. In fact, some children start sucking their thumb while they are still in the womb! Thumb sucking often provides a sense of comfort and helps children self-soothe. For many children, it can even become embedded into their nightly bedtime routine.

Some children naturally stop sucking their thumb as they grow older, while others continue the habit and may need some extra help or support to stop. However, there is no shame if your child still sucks their thumb, as it can be a very difficult habit to break!

Many parents know that their child probably shouldn’t continue sucking their thumb as they get older, but they may not know exactly why. When thumb sucking continues for an extended period of time, it can begin to influence how the mouth develops.

From a myofunctional perspective, we are not just looking at the habit itself. Instead, we are looking at how prolonged thumb sucking may affect the teeth, tongue, lips, breathing patterns, and even speech.

5 areas that can be directly impacted by thumb sucking:

1. Changes to Teeth and Bite

One of the most visible signs of prolonged thumb sucking can be seen through the teeth and how they are positioned. When the thumb frequently rests between the upper and lower teeth, the repeated pressure can begin to influence the position of the teeth over time, potentially creating an opening.

This is called an “open bite,” which occurs when the upper and lower front teeth do not fully meet when biting down.

However, it is important to note that the effects of thumb sucking can vary from child to child. Factors such as how frequently a child sucks their thumb, how long the habit has been present, and the amount of pressure they apply while sucking can all influence how much the teeth and bite are affected.

From a myofunctional perspective, we are particularly interested in these changes because the position of the teeth can also influence how the tongue rests and functions within the mouth.

2. Tongue Resting Posture

Ideally, when we are at rest, our tongue should rest lightly suctioned against the roof of the mouth rather than sitting low in the mouth or pushing forward between the teeth.

Prolonged thumb sucking can interfere with the development of this resting posture. When the thumb is in the mouth, the tongue has to adapt and move out of the way to make room for it. Over time, your child may become accustomed to this new position and continue to keep their tongue low or push it forward between the teeth, even when their thumb isn't in their mouth.

Proper tongue resting posture is an important part of healthy oral development. We want the tongue to learn to rest in the correct position throughout both the day and night rather than continually sitting low or forward in the mouth.

3. Open Mouth Resting Posture

Thumb sucking may also contribute to an open mouth resting posture.

When a child frequently has their thumb in their mouth, their lips naturally remain apart to make room for the thumb. Over time, this open mouth posture may become more ingrained, and the lips may continue to rest apart even when the thumb is not in the mouth.

Ideally, at rest, we want the lips to remain gently closed with the tongue resting against the roof of the mouth. When the mouth consistently remains open, it can also make it more difficult for the child to establish appropriate tongue resting posture and nasal breathing patterns.

4. Mouth Breathing

Going along with an open mouth posture, when the lips are resting apart and the tongue is resting low in the mouth, a child may become more accustomed to breathing through their mouth rather than their nose.

Our goal is for children to primarily breathe through their nose when they are at rest. Nasal breathing allows the lips to remain closed and helps support appropriate tongue resting posture.

It is important to remember, however, that thumb sucking is not the only reason a child may breathe through their mouth. Nasal congestion, allergies, enlarged tonsils or adenoids, and other airway concerns can also contribute to mouth breathing. During a myofunctional evaluation, we look at the child's overall breathing pattern and can help determine whether an evaluation from another provider may also be beneficial.

5. Speech Sound Production

Prolonged thumb sucking can also have an impact on speech sound production for some children.

If thumb sucking contributes to an open bite or forward tongue posture, some children may begin to push their tongue forward when producing certain sounds. This can be especially noticeable on sounds that require careful placement of the tongue behind the teeth, such as /s/, /z/, /t/, /d/, /n/, /l/, “sh,” “ch,” and “j”. 

This does not mean that every child who sucks their thumb will develop speech sound difficulties. However, if your child continues to suck their thumb and you are also noticing that their tongue comes forward when they speak, a myofunctional evaluation can help determine whether their oral resting posture or bite may be contributing to their speech patterns.

When Should You Consider a Myofunctional Evaluation?

Every child is different, and some children will naturally stop sucking their thumb earlier than others. For children who need some additional support, habit elimination does not have to be a negative or stressful experience.

If your child is 4 years old or older and still sucking their thumb, a myofunctional evaluation may help you piece together how the habit could be affecting their oral development.

During an evaluation, we will look at your child's:

• Tongue position and resting posture

• Lip closure

• Breathing patterns

• Bite and dental development

• Speech production

• Swallowing patterns

Most importantly, seeking an evaluation does not mean that you or your child has done anything wrong. Thumb sucking is a very common oral habit, and some children simply need more support than others to move away from it.

Ready to Help Your Child Kick the Habit?

At Rooted Speech and Myo, we will walk you and your child through our habit elimination program, providing both you and your child with the tools, strategies, and support needed throughout the process.

Our goal isn't to make children feel bad about their thumb sucking. Instead, we want to help them understand their habit, feel empowered to make a change, and establish healthy oral habits that will continue to benefit them as they grow.

Feeling ready to kick the habit? Click the here to schedule a myofunctional evaluation at Rooted Speech and Myo. Together, we can help your child say goodbye to the thumb and build healthy oral habits for the future!