Posterior crossbite is when your upper teeth fall inside your lower teeth on one side when you bite down. An anterior crossbite, which is similar to an underbite, is what occurs when your top front teeth fall behind your lower front teeth when you bite down. Crossbites are caused by a variety of factors. If one or both of your parents has a crossbite, there’s a good chance you could inherit it. Another cause is jaw size — if your upper jaw is smaller than your lower jaw, or your jaws are mismatched in size, you could develop a crossbite.
A crossbite is more than just a cosmetic imperfection. So if you suspect that you have a crossbite and wonder how important it is to see a dentist, the answer is “very.” Left untreated, a crossbite can cause conditions such as TMJ or TMD, loose teeth, receding gums, excessive wear of tooth enamel and assymetrical growth of your face and jaw.
Not every crossbite requires correction, but the only way to tell is through proper diagnosis. An Orthodontist can recommend a dental treatment for crossbites, which includes the use of an appliance called a dental “expander.” The expander is widened during the first 1-2 months to expand the jaw, and typically worn for an additional three months to allow the jaw to harden in its new place. Dental braces are sometimes used in conjunction with an expander or are placed after the expander is removed.