Thumb sucking is a common and completely natural behavior in early childhood. Many babies start sucking their thumbs or fingers before birth, and it can even be (adorably!!) visible on prenatal ultrasounds.
But as your child grows, you may wonder if you should begin gently encouraging your child to move away from thumb sucking. Could thumb sucking affect teeth, speech, or jaw development?
In this article, you’ll learn what science says about thumb sucking, when it becomes a concern, and – if it’s right for your family – how to help your child stop thumb sucking naturally and gently.
Why Some Kids Suck Their Thumbs
Thumb sucking begins as a natural reflex that helps babies regulate their nervous system. The rhythmic motion of suckling stimulates the release of calming neurotransmitters like serotonin, lowering stress and promoting a sense of safety.
Many toddlers continue thumb sucking as part of their bedtime routine or during moments of fatigue, anxiety, or boredom. For some children, thumb sucking becomes a form of emotional regulation, a way to cope with transitions, separations, or overstimulation.
You might like this article, too: Understanding Tongue, Lip, and Cheek Ties in Babies & Supporting Infants Through Oral Tie Release
When Might Thumb Sucking Become a Concern?
In infancy, thumb sucking is a completely natural reflex. It helps babies self-soothe, regulate their nervous systems, and feel secure between feedings. During this stage, there’s no need to discourage it – it’s one of the many ways babies comfort and calm themselves as they adjust to the world around them.
For most children, thumb sucking naturally fades between ages 2 and 4 as they find new ways to self-soothe (1). In some cases, though, the habit continues a bit longer, and in many cases that’s completely okay. Every child develops at their own pace, and occasional thumb sucking in an older child is not necessarily a cause for concern.
That said, if thumb or finger sucking is still frequent and strong around age 5 when adult teeth start to come in, it may begin to influence the shape of the mouth or the way teeth align over time (1).
Some things parents and pediatric dentists watch for:
- Dental misalignment, such as overbite or open bite
- Changes in palate shape (roof of the mouth becoming higher or narrower)
- Speech articulation issues, especially with “s” and “th” sounds
- Skin irritation or calluses on the thumb
Every child is different. Some light, infrequent thumb suckers experience no oral effects, while others with strong suction or very frequent sucking may show changes earlier.
If you’re unsure whether it’s affecting your child’s teeth, a pediatric dentist can evaluate and offer guidance.
To learn more about caring for your child’s oral health, read this article: A Guide to Toddler Dental Care
How To Gently Help Your Child Stop Sucking Their Thumb
The first and most important step: Don’t worry – and don’t rush it. Thumb sucking is often a phase that fades naturally with time and maturity. Most children stop on their own once they’re ready.
There’s no need for punishment, pressure, or shame – these can increase anxiety and make the behavior more persistent. Instead, focus on creating an environment of encouragement and calm.
Here are some gentle, effective ways to support the process
1. Understand When and Why
Notice when your child tends to suck their thumb. Is it at bedtime? In the car? During stress? Once you identify triggers, you can try to replace the habit. Try giving your child something else to occupy their hands or mouth during those moments – a soft blanket, stress ball, or a small plush toy for bedtime. For older kids, chewing silicone necklaces or sipping water through a straw can also meet the oral sensory need.
2. Use Positive Reinforcement
Praise progress! For some children, sticker charts or reward systems work well.
3. Avoid Pressure or Public Attention
Try not to draw attention to thumb sucking in public or in front of others, which can lead to embarrassment or shame.
4. Support Calming Sleep Routines
Since thumb sucking is often tied to fatigue or moments of overwhelm, help your child regulate their nervous system naturally. A warm bath and gentle herbal support can help make bedtime soothing and calm, helping your child’s body and mind relax naturally and making thumb sucking less needed over time.
You might like this article, too: Sleep Essentials For Kids
FAQ: What About Bitter-Tasting Nail Polish?
You may have heard of applying bitter-tasting nail polish to discourage thumb sucking. While this approach can sometimes work for older children who want to stop but need a reminder, it’s rarely effective for younger kids and may create stress or feelings of punishment.
If you and your older child decide together to give this method a try, it’s best to use it only for a short period of time and alongside positive encouragement. The goal should always be to empower your child, not surprise or shame them.
The active ingredient in most of these products is denatonium benzoate, a compound considered the bitterest substance known to humans. It’s added in tiny amounts to create an unpleasant taste that helps discourage thumb or nail sucking.
Denatonium benzoate itself is not toxic in the very small concentrations used in these formulas, but prolonged or frequent use isn’t recommended.
When To Seek Professional Support for Thumb Sucking
If thumb sucking continues beyond age 6 or 7, or you notice visible dental changes, it may help to consult a pediatric dentist and/or a myofunctional therapist.
A pediatric dentist can evaluate whether thumb sucking is affecting the palate or tooth alignment and if it is, they may suggest simple, temporary tools to gently discourage the habit (2), such as:
- Thumb guards or finger covers made of soft, child-safe material to act as a reminder without causing discomfort.
- Removable dental appliances, sometimes called habit appliances, rest comfortably in the mouth and make sucking less satisfying without causing pain.
Summary
Thumb sucking is a completely normal and comforting habit for young children – one that most outgrow naturally with time and maturity. For some kids, though, especially if thumb sucking continues beyond age five, it can start to affect teeth and oral development. Thumb sucking in an older child is not an emergency and the best approach is always one that is gentle and supportive. It can be helpful to understand when and why your child sucks their thumb, to offer calm alternatives, and to celebrate small wins! If the habit persists into school age or begins to impact the teeth or speech, a pediatric dentist or myofunctional therapist can help.
References:
- American Academy of Pediatrics. (2020). Pacifiers and Thumb Sucking. HealthyChildren.org. https://www.healthychildren.org/English/ages-stages/baby/crying-colic/Pages/Pacifiers-and-Thumb-Sucking.aspx
- Thumb sucking and pacifier use. (2007). The Journal of the American Dental Association, 138(8), 1176. https://doi.org/10.14219/jada.archive.2007.0331
