Thumb Sucking and Pacifiers: When to Worry

By Lovik Mirzaeian, DDS. Updated October 2026.

Thumb sucking and pacifier use are normal in babies and toddlers and usually nothing to worry about before age three. The habit becomes a concern when it continues past age four, when it is vigorous rather than gentle, or when the adult front teeth are about to come in, which happens around age six. By then a strong sucking habit can push the upper front teeth forward, tip the lower teeth back, and narrow the upper jaw, and those changes do not always correct themselves.

Most children stop on their own between two and four, and their teeth usually look normal by the time the adult teeth arrive. The children I worry about are the ones still sucking hard at five, six, and seven.

Why Babies Suck in the First Place

Sucking is a reflex present before birth. It is how babies feed, and it is also how they calm themselves. A thumb or a pacifier gives a baby a way to settle without a parent, which is why the habit is so hard to give up and why I would not try to stop it in an infant. Pacifiers at sleep times in the first year have been associated with a lower risk of sudden infant death, which is why pediatricians often recommend them.

The habit is not a fault. It is a comfort tool that has outlived its purpose in a child who keeps it too long.

What the Habit Does to the Mouth

A thumb pressed against the roof of the mouth for hours a day does three things. It pushes the upper front teeth outward and the lower front teeth inward, so the teeth do not meet and an open space appears between them when the child bites down. The cheeks pull inward with every suck, which narrows the upper jaw over time and can leave the upper back teeth biting inside the lower ones. And the tongue, which normally rests on the palate and helps it widen, is held low.

How much of this happens depends on how many hours a day the child sucks, how hard, and for how many years. Five minutes at bedtime is very different from all night and much of the day.

Pacifiers cause similar changes, though they tend to produce a more even effect on the bite and they are easier to take away, because a parent controls the pacifier and cannot control a thumb. Both habits can also affect speech, particularly the sounds that need the tongue against the front teeth. The American Dental Association has a helpful page for parents on what to expect and when to act.

The Ages That Matter

Before age two, do nothing. Between two and four, encourage stopping gently but do not fight over it. Changes in the baby teeth at this age usually resolve once the habit ends, because the bones are still soft and growing. Around age four, start actively helping the child stop, because the window is closing. By age six the permanent upper front teeth are erupting, and a strong habit at this point shapes where they settle. A child who is still sucking at seven or eight needs a plan, and the sooner the better.

I check for these changes at every childhood visit. Our post on when a child should first see a dentist explains why we like to see them by the first birthday, which is early enough to talk about habits before they matter.

Gentle Ways to Help a Child Stop

Do not scold

Punishment and nagging make the habit stronger, because stress is exactly what drives the child to suck. Ignore the thumb when it is in and notice, warmly, when it is out. Praise works far better than criticism at this age.

Find the triggers

Most children suck at specific times: falling asleep, watching television, in the car, when tired or upset. Once you know the pattern, you can offer a substitute at those moments, such as a stuffed animal to hold with both hands, a story, or a small fidget toy. Keeping hands busy is half the battle.

Use a chart and small rewards

A sticker chart with a simple goal, such as no thumb during the bedtime story, gives the child ownership. Keep goals small and stretch them slowly.

Night time helpers

For children who only suck in their sleep and genuinely want to stop, a sock or a soft glove on the hand, or a bandage on the thumb, acts as a reminder rather than a barrier. Bitter nail coatings exist but I am not enthusiastic about them; they feel like punishment to a small child.

Pacifiers

Pacifiers are easier. Limit them to the crib from about age one, then pick a stopping point, prepare the child for a few days, and remove them all at once. Some families trade them in for a gift. Expect a few rough nights and then it is done. Never dip a pacifier in honey or sugar, which causes decay, and do not clean one in your own mouth, which transfers cavity-causing bacteria.

When a Reminder Appliance Makes Sense

A small number of children, usually six and older, cannot stop despite wanting to. For them, a simple appliance fixed to the upper back teeth with a small gate behind the front teeth removes the satisfying feel of the thumb against the palate. It does not hurt, most children stop within weeks, and it comes out once the habit is gone. This is a last step, not a first one.

When to See a Dentist

Bring your child in if the habit is still going strong at four, if you notice the front teeth sticking out or not meeting, if the child breathes through the mouth at rest, or if speech seems affected. Persistent sucking and mouth breathing often go together, and our post on mouth breathing in children explains why. As a family dentist we see these habits every week, and a routine exam is the easiest place to talk them through.

Frequently Asked Questions

At what age should a child stop sucking their thumb?

Ideally by age four, and definitely before the adult front teeth come in around age six. Most children stop on their own between two and four. Changes to the bite that happen before four usually correct themselves once the habit ends.

Does thumb sucking damage teeth?

A gentle habit in a toddler rarely does lasting harm. A strong, frequent habit that continues past age four can push the upper front teeth forward, create an open gap between the front teeth when biting, and narrow the upper jaw. The longer and harder the habit, the more likely the changes persist.

Are pacifiers better than thumb sucking?

Pacifiers cause similar bite changes if used for years, but they are easier to stop because a parent controls them. Pediatricians often recommend pacifiers at sleep times in the first year. Plan to limit them to the crib by age one and remove them fully by age two to three.

How do I get my child to stop sucking their thumb?

Avoid scolding, which increases stress and makes the habit worse. Identify when the sucking happens, offer a substitute like a toy to hold, use a sticker chart with small goals, and praise success. For an older child who cannot stop, a dentist can fit a gentle reminder appliance.

Wondering If It Is Time to Stop the Thumb? Dr. Mirzaeian Can Help

A quick look at your child’s bite tells us whether the habit is doing any harm and how urgent it is. If you would like an honest opinion and a plan that does not involve a fight, contact us to set up a consultation.

Lovik Mirzaeian, DDS has achieved extensive training in multidisciplinary dental treatments. His credentials include Dental Implants, Cosmetic Dentistry, Full Mouth Reconstruction, Endodontics, Oral Surgery, Orthodontics, and Sleep Sedation. Our office puts your comfort and smile first, and we are dedicated to giving you top-notch dental care. Get ready to show off your perfect smile!

Looking for a trusted family dentist in Clovis? Dr. Mirzaeian welcomes new patients of all ages.