Thumbsucking is a natural reflex for babies. It soothes them, helps them fall asleep, and gives them a sense of comfort when the world feels big and strange.
About 90% of toddlers suck their thumbs or fingers at some point, and as long as they break the habit by age four, it shouldn’t have any affect on their teeth. Most kids will naturally stop on their own by the time they’re ready for preschool. However, if they’re still sucking their thumb at age five or six, it can change the shape of their mouth and affect the development of their permanent teeth.
Even Little Kids Need Dental Checkups
All kids need dental care, no matter how young they are. Baby teeth can get cavities, too, so dental checkups are important!
First, we’ll give their teeth a thorough cleaning to remove any cavity-causing tartar. Then we’ll take x-rays to check for deeper decay and to get a closer look at how their permanent teeth are developing. We can also provide fluoride treatments to help prevent cavities in their baby teeth.
And over the years, we’ll keep an eye on habits like thumbsucking that affect their bite and jaw development. If we notice any changes, we’ll tell you right away. That way you can help your child break the habit early on, before it causes so much damage that they’ll need orthodontic work as a teen.
What Types of Dental Problems Does Thumbsucking Cause?
Most kids grow out of thumbsucking on their own, but when the habit sticks around past age three or four, it can start reshaping the mouth in ways that go beyond a bad habit. Constant pressure from a thumb can push the upper front teeth forward and pull the lower teeth back, creating a gap dentists call an open bite.
Even after a child quits, the roof of the mouth can stay narrowed, and the bite misaligned if the habit was intense or lasted for years. Passive thumb resting causes far fewer changes to the bite than aggressive, all-day sucking, so intensity matters just as much as duration.
Here’s the full picture of what a prolonged thumbsucking habit can do.
Dental problems related to thumbsucking:
- Open bite. The front teeth stop meeting when the mouth closes, leaving a visible gap even when your child bites all the way down
- Gapped or protruding front teeth. Spacing issues or that classic “buck teeth” look, caused by the thumb pushing teeth out of position
- Narrow or high palate. The roof of the mouth molds around the shape of the thumb since the bone is still soft in young kids
- Jaw shape changes. Uneven pressure over time can throw off how the upper and lower jaw grow in relation to each other
- Misaligned permanent teeth. Adult teeth follow the path the primary teeth and jaw have already set, so an unresolved habit often carries straight through
- Posterior crossbite. The upper jaw narrows and the back teeth no longer line up with the lower teeth, and this one rarely fixes itself once the habit stops
- Increased overjet. A separate measurement from open bite, tracking how far the upper front teeth stick out past the lower ones
- Tooth crowding. Less room for teeth to come in straight as the jaw shape shifts
- Mouth breathing. Changes to the palate can make it harder to keep the lips sealed, so some kids shift toward breathing through the mouth, especially at night. This leads to dry mouth, plaque buildup, and cavities.
When to worry:
Watch out for warning signs like calluses or redness on the thumb, a noticeable lisp or trouble with certain sounds. If their top and bottom front teeth don’t touch when they bite down, or the roof of their mouth looks narrow and high, you should consult a pediatric dentist.
If your child is still sucking their thumb and you’re noticing changes in how their teeth line up, bring it up at their next visit. We’ll take a look and talk through some gentle strategies to help break the habit. They might still need some orthodontic treatment in the future, but the sooner the stop, the less damage there will be.
Helping your child break the habit:
- Praise and reward them when they don’t suck their thumb. Positive reinforcement (rather than scolding or shaming) is always the best approach.
- Try to figure out what’s triggering the habit, whether it’s boredom, tiredness, or anxiety. If you know why your child is sucking their thumb, it will be easier to find a way to cure it.
- Find other ways to keep their hands busy to distract them from thumbsucking. Fidget toys, sensory toys, or any toys that use both hands will help keep the thumb away from the mouth.
- A thumb guard or cover can help too, especially overnight when kids tend to suck out of habit rather than choice. These fit over the thumb like a small glove or shield, so there’s nothing to latch onto even if the reflex kicks in while they’re asleep.
- If none of that gets the job done, an orthodontist can step in with an appliance called a palatal crib or tongue crib. It’s a small device that attaches to the back teeth and sits along the roof of the mouth, and it physically blocks the thumb from resting against the palate, which helps break the habit even when a child isn’t consciously trying to stop. Most orthodontists reserve this option for kids who’ve tried everything else and still can’t shake it on their own.
Every child responds to something different, so it’s worth trying a few of these together rather than picking just one. And if they simply can’t break the habit, we may be able to help.
Pediatric Dental Care in Flagstaff
Looking for a family dentist in Flagstaff?
At Country Club Dental, we accept patients as young as three years old. Our dentist, Dr. Paul Whitney, is great with kids and our team always tries to make going to the dentist a positive experience. Reach out to Country Club Dental to schedule checkups for your kids today!
Photo by Sean Foster on Unsplash with permission under the Creative Commons license for commercial use 8/5/26.
