A cross bite is where the upper jaw is narrower than the lower jaw which can cause the upper teeth to bite on the inside of the lower teeth.
This is best corrected in younger patients usually around the age of 9 to 11 years, while their jaw is still developing and malleable.
Cross bites in adults can also be corrected however usually require a combination of orthodontic expansion and a surgical procedure done by a maxillofacial surgeon to free up the upper jaw bone.
Cross bites are treated with appliances such as a:
Quad helix expander or RME (Rapid Maxillary Expander) which are appliances that are worn on the upper jaw and it fixed in placed. Your Orthodontist will do adjustment of these every 6 to 8 weeks.
Removable plates which are custom made to fit on the upper jaw and can be taken in and out. Your Orthodontist will see you every 6 to 8 weeks for adjustments.