Abby Barnes, M.S., CCC-SLP
Thumb sucking is a common self-soothing behavior in babies and young toddlers. It can seem cute, but over time, you may wonder if thumb sucking can cause a speech delay or other problems.
Speech therapists get this question often, so let’s talk about it! Read on to learn why children suck their thumb, whether thumb sucking can cause a speech delay, and how to know when it’s time to help your child stop thumb sucking.
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Start the screenerWhat causes thumb sucking?
Thumb sucking is completely normal in infancy and early toddlerhood. It helps babies regulate themselves and feel secure.
Many toddlers stop thumb sucking on their own. But when thumb sucking continues beyond age 2, or happens often and with intensity, it can start to affect how a child’s mouth develops.
Can thumb sucking cause a speech delay?
In some children, it’s possible for prolonged thumb sucking to contribute to speech problems. Here’s how thumb sucking can affect a child’s speech:
Changes in oral structure
Long-term thumb sucking can change the way the mouth grows. A child might develop:
A high, narrow palate (roof of the mouth)
An open bite (when the front teeth don’t touch when the mouth is closed)
A forward tongue resting posture
These changes can make it harder to produce speech sounds clearly.
Tongue thrust or reverse swallow
Thumb sucking often encourages the tongue to push forward when the child swallows or speaks. This is called a tongue thrust. Tongue thrust can lead to a frontal lisp or problems pronouncing sounds like /s/, /z/, /t/, /d/, /n/, and /l/.
When should my child stop thumb sucking?
If your child is sucking their thumb but you’re not sure if it’s a problem, here is some general guidance to follow. If your child is doing the following, it’s time to stop thumb sucking:
Your child is still thumb sucking regularly after age 2
Their teeth are shifting or not aligning properly
You notice unclear speech or difficulty with specific sounds
There’s a noticeable lisp, or their tongue is pushing forward when they talk
Your child’s mouth is often open at rest
How to stop thumb sucking
If you’re concerned about your child’s thumb sucking, here are a few ways to help them stop:
1 Gently start to phase out the habit
Avoid shaming or punishing your child. Instead, offer comfort and praise for thumb-free moments. For older children, involve them in setting goals to stop the habit.
2 Positive reinforcement
Make sure to tell your child when you notice that they’re not sucking their thumb. Try saying, “I like how your thumb isn’t in your mouth!” or “Good job not sucking your thumb!”
3 Consistently remind them to stop
It’s OK to tell your child to stop. They will probably need frequent reminders. Just stay calm, and don’t get upset with them. Thumb sucking can be a hard habit to break.
What professionals can help with long-term thumb sucking?
It’s important to know that long-term thumb sucking may need support from professionals. One is a pediatric dentist. They can evaluate any changes in bite or jaw structure, and they may offer guidance to help your child stop thumb sucking.
It’s also important to see a speech-language pathologist, also known as a speech therapist. They can assess your child’s speech and oral structures. If thumb sucking is affecting your child’s speech development, speech therapy can help them improve how clearly they speak. A speech therapist can teach your child exercises to practice forming their sounds correctly.
You can take our free online screener to find out if your child’s speech is on track for their age.
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Get startedSpeech therapy can help with the effects of thumb sucking
If you think your child’s thumb sucking may be affecting the clarity of their speech, contact us here at Expressable. We can help you schedule an evaluation to determine whether your child could benefit from speech therapy. Find the right speech therapist for your child here.
FAQs about thumb sucking and speech delay
1 Can thumb sucking cause a speech delay?
In some kids, long-term thumb sucking can lead to speech problems. Thumb sucking can change the way the mouth grows, which makes it harder to produce speech sounds clearly. It can also lead to a frontal lisp.
2 How do I know if I should help my child stop thumb sucking?
Your child should stop thumb sucking if they’re past age 2, their teeth are shifting, or they have unclear speech or a lisp. You can take our free online screener to find out if your child’s speech is on track for their age.
3 What should I do if I’m concerned about my child’s thumb sucking?
Talk with a pediatric dentist and a speech therapist. They can help with problems related to oral development and speech clarity. You can get matched with a speech therapist at Expressable by clicking here.
How Expressable Can Help
Concerned your child isn't reaching age-expected milestones? Looking for communication support from a professional? Expressable is a national online speech therapy practice serving children and adults. We treat all major areas of communication and feeding, offer flexible hours including evenings and weekends, and accept most major health insurance plans. We’re proud to have earned more than 3,000 5-star reviews from our clients (4.9/5 average).
Our therapy model is centered on parent and caregiver involvement. Research proves that empowering caregivers to participate in their loved one’s therapy leads to better outcomes. That’s why we combine live, 1-on-1 speech therapy with personalized education and home practice activities for faster progress.
Communication is more than words. It’s how we share how we feel and show who we are. We’re here to help you or your child do just that.
