In a normal bite, all of the upper teeth should lay off on the outside of the lower teeth. When any of the lower teeth are on the outside of the upper teeth, this is a crossbite. A crossbite that is left untreated can lead to growth abnormalities where the lower jaw can outpace the upper jaw or a jaw that “leans” to the left or right. Crossbites are easiest to correct before puberty and its associated growth spurt. The more the jaw grows (puberty) the worse the crossbite becomes.
There are 2 types of crossbites, anterior and posterior. It is possible to have both an anterior and posterior crossbite.
Anterior & Posterior
Our typical treatment for a crossbite is interceptive therapy or Phase 1 treatment. Phase 1 treatment usually includes braces and a palatal expander to fix the crossbite and lasts about one year. Phase 1 treatment is not a substitute for traditional (comprehensive) braces at the age of 12-13 but a supplement to comprehensive treatment. In our office, a patient with a crossbite will have Phase 1 treatment of 12 months around the age of 9-10, then a break of about 2 years, and finally Phase 2 treatment of 12 months around the age of 12-13. This adds up to 2 years (24 months) of active treatment within 4 total years. Remember that comprehensive orthodontic treatment cannot be completed until all of the permanent teeth have erupted.