A crossbite is an irregularity of the occlusal surface of the tooth. It happens when one or more teeth has a buccal (toward the cheek) or lingual (toward the tongue) position when compared to its matching tooth above or below it. The crossbite can be “anterior”, in which case you have a negative overjet, also known as a class III skeletal abnormality or prognathism. You can have a “posterior” crossbite, which often means you have a narrow maxillary bone and a narrow upper dental arch. You can have a crossbite on one side or on both sides of the mouth and if you don’t treat a crossbite quickly enough, the bone can reshape itself in an abnormal position.
Causes of crossbite:
The causes of a crossbite are usually hereditary and come from your genes. In other cases, it can be a delayed loss of baby teeth or an unusual eruption of the teeth. If it is a genetic problem, the bone of the lower jaw is usually wider than the bone of the upper jaw. It can cause the teeth to be misaligned on one side of the mouth or on both sides of the mouth. If it is from a delayed loss of a baby tooth or an abnormally erupted tooth, it can affect just a portion of the occlusion. Thumb sucking can contribute to a crossbite by constricting the width of the palate and deforming the upper bone of the palate. It usually does not correct itself and needs some kind of orthodontic correction. In rare cases, the presence of mouth breathing can cause defects in the shape of the maxilla and can affect teeth alignment.
Symptoms:
The symptoms of a crossbite can be painful chewing and a painful jaw and teeth. It can also affect chewing in such a way that the temporomandibular joint (TMJ) or jaw joint is inflamed. This inflammation causes pain in the TMJ and sometimes headaches.
Complications:
Complications of a crossbite can be periodontitis and gingivitis, tooth loss due to malocclusion and degeneration of the temporomandibular joint, causing arthritis of the TMJ and wearing away of the joint surface. This can result in the need for surgery to replace the TMJ completely.
Crossbite prevention:
You can prevent a crossbite by stopping thumb sucking early in life so the upper palate doesn’t become narrowed and malformed. You can have the baby teeth removed when expected so that the adult tooth beneath it doesn’t have to come out crooked. Many types of crossbite, however, cannot be prevented and must be treated when noted.
Treatment options:
Orthodontists need to treat a crossbite as soon as possible so that the teeth can be realigned. If mouth breathing is part of the cause, a tonsillectomy and adenoidectomy should be performed before the patient undergoes orthodontic therapy. The first part of treatment involves maxillary expansion. This makes the upper jaw broader using a maxillary expander. It widens the jaw when worn nightly for a couple of months. A key turns the device and gradually increases the width of the palate.
After the palate has expanded enough, orthodontic devices are necessary to straighten the teeth. This means a full set of braces for a total of one to two years in order to create an ideal bite.