Children
Is thumb sucking bad for teeth?
17 August 2026 · The Dentist, Al Qusais, Dubai
The short answer
Thumb sucking itself isn't harmful in infants and toddlers, it's a normal comforting reflex. Problems start if the habit continues past age four or five, especially if it's intense and frequent, because it can push front teeth forward, create an open bite, and narrow the upper jaw. Most children stop on their own by age four. If yours hasn't, a dentist can check whether the teeth or palate have already started to shift and suggest gentle ways to help the habit end.
When it stops being just a habit
Nearly every baby sucks a thumb or finger. It's soothing, it helps with sleep, and in the first couple of years it has no lasting effect on the teeth because baby teeth are still settling into position anyway.
The concern is duration and intensity, not the habit existing at all. A child who sucks passively and only at bedtime is very different from one who sucks vigorously for hours during the day, with an audible popping sound when they stop. The second pattern, if it carries on past age four, is far more likely to move teeth.
Age four to five is the rough cutoff dentists watch for. By then, permanent teeth are getting ready to come in, and the jawbone is more responsive to sustained pressure. A habit that fades naturally before that point rarely leaves any mark.
What sustained sucking does to a growing mouth
The thumb sits behind the upper front teeth and under the tongue. Hours of pressure each day pushes the upper front teeth forward and tips the lower front teeth backward, which can create an overjet, that gap where the top teeth stick out past the bottom ones.
It can also stop the front teeth from meeting properly, called an anterior open bite, where the child can't bite down on a piece of food with their front teeth even when their back teeth are together. In more prolonged cases, the roof of the mouth narrows and arches upward around the shape of the thumb, which sometimes affects speech, particularly sounds like s and th, and can make nasal breathing harder.
None of this happens overnight, and none of it is the parent's fault. It's simple mechanics: sustained pressure on soft, growing bone reshapes it. The degree of change depends on how many hours a day the thumb is in the mouth, how much force is behind the sucking, and how many years it continues past the age when permanent teeth start arriving.
Helping the habit end without a fight
Pressure and punishment tend to backfire, they turn thumb sucking into a source of anxiety, which can actually make a child cling to it harder. Gentler approaches work better: praise and small rewards for hours or days without sucking, a bandage or bitter-tasting nail polish on the thumb as a physical reminder rather than a punishment, and addressing the trigger, since many children suck more when tired, bored, or anxious.
Involve the child in the plan rather than announcing it to them. A five or six year old who picks their own reward chart is far more invested than one who's simply told to stop. Most children respond within a few weeks once they're old enough to understand and want to participate.
If the habit has already gone on for a couple of years past age four, or you can see the front teeth flaring outward or a gap between the upper and lower teeth when your child bites down, it's worth having a dentist look. At The Dentist in Al Qusais, Dr. Faris Alkhanafseh and Dr. Mohammad Nour see children as part of general family checkups and can tell you honestly whether what you're seeing is likely to self correct once the habit stops or whether it needs monitoring as the permanent teeth come in. The first checkup is free for new patients, and you can book a time through WhatsApp or at thedentist.ae/book.
This article is general information, not a diagnosis. If you are in Dubai, the free first checkup at our Al Qusais clinic is the fastest way to get an answer about your own teeth.