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Conditions · Children, teens & adults
Open Bite: Causes, Tongue Thrust and Treatment Options
An open bite is when the front teeth don’t touch when the back teeth are closed together, leaving a visible gap. In children it is often linked to thumb sucking, a dummy or tongue posture; in others it reflects jaw growth. At Yonsei Baro near Isu Station, Dr. Sally Chaekyung Lee treats the cause, not just the gap.
Open bite at a glance
| Question | In brief |
|---|---|
| What it is | A vertical gap between the upper and lower front teeth when the back teeth are together (anterior open bite); less often, back teeth that don’t meet |
| Common causes | Thumb, finger or dummy sucking; tongue thrust or low tongue posture; mouth breathing; a long, vertical jaw growth pattern |
| Usually noticed | Often in toddlers and young children with a sucking habit; persistent open bites are usually spotted around ages 6–10 |
| How it’s assessed | Habit and swallowing check, digital scan, X-rays or 3D CT for the vertical jaw pattern and roots, face analysis, growth assessment |
| Treatment options | Stopping the habit, habit appliances and tongue exercises, braces or clear aligners, temporary anchorage screws; surgery for some severe skeletal cases |
| Typical approach: children | Address the habit first, as many habit-related open bites improve once it stops; appliances if needed |
| Typical approach: adults | Braces or aligners, sometimes with anchorage screws to move back teeth upwards; combined surgical care for marked skeletal patterns |
What causes an open bite?
The front teeth are held in a balance between the lips, cheeks and tongue. Anything that sits between them for long periods, or pushes against them repeatedly, can stop them from meeting:
- Sucking habits: a thumb, finger or dummy held between the front teeth for many hours a day
- Tongue thrust: the tongue pushing forward between the front teeth when swallowing or speaking
- Low tongue posture and mouth breathing , which change the forces on the teeth and jaws
- Skeletal pattern: some people inherit a long, vertical growth pattern where the back of the jaws grows more than the front
Often several of these act together. A thumb habit may start an open bite, and the tongue then rests in the gap and keeps it open after the habit stops.
Does my child need treatment now?
In young children, an open bite caused by a dummy or thumb often improves on its own once the habit stops, particularly if it stops before the adult front teeth come in. The first step is usually gentle help to break the habit. Our guide to thumb sucking and pacifiers has practical ideas.
If the open bite persists after the habit has stopped, or a tongue thrust is keeping it open, Dr. Lee may suggest a habit or functional appliance together with simple tongue and lip exercises. When the cause is mainly skeletal, she will monitor growth and plan the timing; see early orthodontic treatment .
How is an open bite treated?
Treatment depends on whether the gap comes from the front teeth not having come down far enough, from the back teeth being too tall, or from the jaws themselves. Options include closing the bite by moving front teeth, moving back teeth upwards with the help of small temporary anchorage screws, and, for marked skeletal open bites in adults, combined orthodontic and surgical treatment with an oral and maxillofacial surgeon.
Braces or aligners for an open bite?
Both are used. Clear aligners such as Invisalign cover the biting surfaces of the back teeth, which can help in some mild to moderate open bites in teens and adults. Fixed braces may be preferred when larger vertical movements or anchorage screws are needed. Dr. Lee will explain which she recommends for your bite, and why.
How Dr. Lee assesses an open bite
Dr. Lee watches how your child swallows, speaks and rests the lips and tongue, and asks about habits and sleep. A digital scan records the bite, and a RAY Quantum 5D CT scan shows the vertical proportions of the jaws and the roots of the front teeth. A RAY Face scan adds the lips and facial height. For children, growth analysis indicates how much vertical growth may still come. Published cases, shared with consent, are on our before-and-after page ; results vary.
Why open bites can come back
Open bites are among the bite problems most prone to relapse, usually because the tongue habit or posture that helped cause them is still there. Long-term retainer wear, and continuing tongue and lip exercises where advised, help keep the front teeth together.
Open bite FAQs
Will my child’s open bite close once they stop sucking their thumb?
Often it improves, especially when the habit stops before the adult front teeth come in. If the tongue has learned to rest in the gap, or the jaw pattern is vertical, the bite may not close fully on its own. A check a few months after the habit stops shows whether it is improving or needs help.
What is tongue thrust?
Tongue thrust is a swallowing pattern in which the tongue pushes forward between or against the front teeth instead of resting behind them. It is normal in infants and usually changes with age. When it persists, it can help keep an open bite open. Exercises and, sometimes, an appliance can help retrain it.
Can an open bite affect speech?
It can. Some children and adults with an open bite have difficulty with sounds such as “s” and “z”, because air escapes through the gap between the front teeth. Speech often improves as the bite closes, and a speech therapist can help where needed.
Can an adult open bite be closed without jaw surgery?
Many can. Mild and moderate open bites in adults are often treated with braces or aligners, sometimes using temporary anchorage screws to move the back teeth upwards so the front teeth can meet. When the open bite comes mainly from the shape of the jaws, Dr. Lee will discuss whether a surgical opinion makes sense.
Is an open bite linked to mouth breathing?
They are often seen together. Breathing through the mouth changes where the tongue and lips rest, which may contribute to an open bite and a vertical growth pattern in children. If your child breathes through the mouth most of the time, an ENT doctor may need to check the nose, adenoids and tonsils.
Medically reviewed by Dr. Sally Chaekyung Lee, DDS, PhD
Board-certified orthodontist (Korea Ministry of Health and Welfare) · Adjunct Professor of Orthodontics, Yonsei University · Last updated October 2026
This page is general information, not a diagnosis. Treatment results and duration vary from person to person. Orthodontic treatment can cause temporary discomfort and, in some cases, root shortening, gum recession or tooth decay if oral hygiene is poor; teeth can relapse if retainers are not worn as instructed.
Concerned about a gap between the front teeth?
Book an examination and Dr. Lee will look at habits, tongue posture and jaw growth, then explain the options in English. Isu Station Exit 2 · Open until 9 PM Mon & Thu · Saturdays 9 AM–2 PM.