What is a crossbite?
In a healthy bite the upper teeth sit slightly outside the lower teeth, like the lid of a box. In a crossbite one or more upper teeth bite inside the lower ones instead. A front crossbite involves the upper front teeth sitting behind the lower front teeth. A back (posterior) crossbite involves the upper cheek teeth closing inside the lower ones, on one side or both.
A crossbite is one kind of malocclusion, the general word for teeth that do not meet properly. It is different from an underbite, where the whole lower jaw sits forward, although a front crossbite can look similar when it involves several teeth.
| Type | What you see | Common cause |
|---|---|---|
| Single tooth crossbite | One upper front tooth sits behind the lower teeth | Tooth erupted tilted, or was crowded out of position |
| Back crossbite, one side | Jaw shifts to one side when you close | Narrow upper jaw forcing a sideways slide |
| Back crossbite, both sides | Upper arch looks narrow, back teeth bite inside the lower ones | Narrow upper jaw, often with a thumb or dummy habit in childhood |
| Skeletal crossbite | Upper jaw is narrow compared with the lower jaw | Jaw growth pattern, often inherited |
Common types of crossbite: general information, not a diagnosis.
Causes of a crossbite
Most crossbites have a simple cause. Crowded teeth can push a tooth to grow in behind its partner. A baby tooth kept too long can steer an adult tooth the wrong way. A narrow upper jaw is the commonest reason for a back crossbite, and long-standing thumb sucking, dummy use or breathing through the mouth can all narrow the upper arch in a growing child. Genetics play a large part in jaw size and shape.
A back crossbite often makes the lower jaw slide to one side to find a comfortable bite. Left alone in a child, this can lead to uneven jaw growth, uneven wear on teeth and, in some people, jaw discomfort. If you notice that the lower jaw or chin looks off-centre, read our guide on an asymmetrical jaw.
How a crossbite is corrected
The earlier a crossbite is found, the simpler the fix. In a growing child with a narrow upper jaw, a palatal expander can widen the upper arch while the bones are still flexible. A single tooth in crossbite may be moved with a small removable or fixed appliance.
In teenagers and adults the jaw bones have finished growing, so treatment usually relies on braces or clear aligners, sometimes with elastics. If the upper jaw is truly too narrow in a fully grown adult, an orthodontist may discuss assisted expansion or jaw surgery. Which route suits you depends on an examination and X-rays at an orthodontic consultation.
Common questions
Can a crossbite correct itself?
A crossbite caused by the jaw or the way the teeth meet rarely corrects itself, and a back crossbite in a child usually stays unless it is treated. A single tooth that has just come through may move forward with the tongue in some children, but this should be checked by a dentist rather than waited out.
Is a crossbite bad for your teeth?
It can be. A crossbite can wear teeth unevenly, put extra load on a few teeth and their gums, and in a child encourage uneven jaw growth. Not every crossbite causes problems, but a dentist can tell you whether yours is likely to.
At what age should a crossbite be treated?
Early assessment around the age when the first permanent molars come through, roughly 6 to 8 years, lets an orthodontist catch a narrow upper jaw while it is easiest to widen. Adults can be treated at any age with healthy teeth and gums.
Can aligners fix a crossbite?
Aligners can fix mild and moderate crossbites, especially when only tooth tilt is involved. A true skeletal narrowness of the upper jaw may need an expander or other help first.
About this page
This page is general information, not a diagnosis or a quotation. Prices are prevailing Lucknow market ranges. Your own treatment and cost are determined after an examination. For questions about your own case, call +91 83036 12717.