Thumb sucking and teeth: when to worry

Page updated October 22, 2026.

Thumb sucking is normal for babies and toddlers, and most children stop on their own between ages 2 and 4 (ADA). It becomes a dental problem when it goes on longer or is vigorous: it can push the front teeth forward, stop the front teeth from meeting, and narrow the upper jaw (AAO). Here is when to worry, what it does to teeth, and how to help a child stop.

Why children suck their thumbs

Sucking is a natural reflex. The ADA says it can make babies feel secure and happy and help them learn about their world, and young children may suck to soothe themselves and fall asleep (ADA). So for a baby or toddler, thumb sucking isn't a habit to break; it's a normal stage. What matters is how long it lasts and how hard the child sucks.

When thumb sucking becomes a problem

Children usually stop sucking between ages 2 and 4, or by the time their permanent front teeth are ready to erupt (ADA). Once permanent teeth arrive, sucking can affect how the mouth grows and how the teeth line up, and it can change the roof of the mouth (ADA). Cleveland Clinic says thumb or finger sucking after about age 4 can contribute to buck teeth (Cleveland Clinic).

Intensity counts as much as age. A child who rests a thumb in the mouth is less likely to have trouble than one who sucks vigorously, and some aggressive thumb suckers develop problems even with their baby teeth (ADA). The AAO notes that some bone changes can be seen as early as 18 months of age (AAO).

Ages: ADA MouthHealthy, Cleveland Clinic and the AAO. Every child is different; ask your dentist about yours.

What thumb sucking does to teeth

Constant pressure from a thumb, finger or pacifier can change how the teeth and jaws develop. The AAO describes three main problems (AAO):

Thumb sucking and tongue thrust

Thumb sucking and tongue thrust often travel together. Tongue thrust is a habit of pushing the tongue forward against the back of the teeth; it's most common in infants, but without treatment it can continue into childhood and even adulthood (Cleveland Clinic). Any object in a child's mouth, including a thumb, holds the jaw and tongue down and forward (Cleveland Clinic). The most common bite problem it causes is an open bite, and it can also contribute to an overbite or underbite (Cleveland Clinic). Some children outgrow it by about age 4 or 5 (Cleveland Clinic). If not, a speech-language pathologist can teach exercises for the tongue, cheeks and lips, known as myofunctional therapy, and braces or aligners can correct the bite once it has changed (Cleveland Clinic).

Pacifiers vs thumb sucking

The ADA says pacifiers affect the teeth in essentially the same ways as fingers and thumbs, but they're often an easier habit to break (ADA), since you can take a pacifier away and can't take away a thumb. Cleveland Clinic suggests stopping pacifiers and sippy cups by about age 3, because they hold the jaw and tongue down and forward (Cleveland Clinic). Long-term pacifier use is also listed among the causes of buck teeth (Cleveland Clinic).

How to help a child stop

Children often suck their thumbs when they feel insecure or need comfort, so the ADA suggests dealing with the cause of the anxiety and offering comfort rather than scolding (ADA). Methods recommended by the ADA and the AAO:

1. Praise your child for not sucking (ADA).
2. Let an older child choose the method of stopping, so it's their project (ADA).
3. Ask the dentist to help. A dentist can encourage your child and explain what could happen to their teeth (ADA).
4. Use a night-time reminder, such as a bandage on the thumb, a sock on the hand (ADA), or a finger loosely wrapped with an elastic bandage (AAO).
5. Try a bitter coating. Bitter-tasting nail polish discourages fingers in the mouth (AAO); a dentist or pediatrician can also prescribe a bitter medication for the thumb (ADA).
6. For pacifiers, cutting the rubber tip breaks the suction seal, for children aged 3 to 4 who still use one (AAO).

Habit appliances

If these don't work, the AAO says certain dental appliances can help keep a child from sucking their fingers and prevent future jaw problems (AAO); the ADA also mentions a mouth appliance as an option (ADA). Among the appliances the AAO lists for early treatment are tongue cribs, palate expanders and growth-guidance appliances (AAO). A tongue crib creates a barrier in the mouth; Cleveland Clinic says most children who need one for tongue thrust wear it for 6 months to a year (Cleveland Clinic).

We haven't found a reliable published price for habit appliances, so ask for a written quote. Many orthodontists offer the first consultation free and with no obligation (AAO).

When to see an orthodontist

The AAO recommends every child have an orthodontic check-up no later than age 7, and lists thumb, finger or pacifier habits that affect the teeth or jaw growth among the problems that may benefit from early treatment (AAO). It says an early visit can help correct harmful habits, guide jaw growth, lower the risk of injury to protruding front teeth and guide permanent teeth into better positions (AAO). Talk to your dentist sooner if you notice changes in your child's baby teeth (ADA), and to the pediatrician or dentist if a tongue thrust continues at age 4 or older (Cleveland Clinic).

If the teeth have already moved, treatment may come in two stages: early treatment while some baby teeth remain, and braces or aligners later (AAO). See phase 1 orthodontics and braces cost for kids.