The majority of orthodontic problems relate to malocclusions, or the improper alignment of the upper and lower teeth when biting or chewing.
Several variations of malocclusions are possible. This article examines crossbites, a malocclusion where the upper teeth are biting inside the lower teeth.
Crossbites frequently are the result of nasal allergies that cause the patient to be a mouth breather. Chronically congested nasal passages can lead to overgrowth of the nose’s interior. Constant mouth breathing also can lead to dry mouth, several other types of malocclusions and long-face syndrome (a longer, narrower face than normal.)
A crossbite also can be caused by a narrow upper jaw, or a mismatch of jaw size and positioning between the lower and upper jaw. It also can result when teeth are reversed in position.
Finally, a crossbite can result from the delayed loss of baby teeth. Some patients hold on to their baby teeth for so long their permanent teeth come in behind the baby teeth, giving the appearance of a second row of teeth.
In addition to mouth breathing, visual cues a patient has a crossbite include snoring, an off-center appearance of the chin; and sliding of the lower jaw to the left or right to facilitate chewing.
If this problem occurs in a patient’s upper jaw, the permanent top, front teeth may end up sitting behind the lower front teeth when chewing. This can occur on either one or both sides of the mouth.
Orthodontist, Dr. Atoosa Nikaeen recommends patients with a crossbite be treated as early as possible. This condition can lead to:
Excessive wear of the teeth
Gum disease, including loss of bone surrounding the tooth
Improper chewing patterns
Temporomandibular joint disorder (TMJ)
An unattractive smile
Several treatment options are available. Dr. Nikaeen may recommend orthodontic treatment begin with a maxillary expansion to broaden the patient’s upper jaw. An expansion appliance is fixed to the roof of the patient’s mouth and widened each night for one to two months. Once the expander has reached maximum width, the patient will need to wear the appliance for roughly three more months, allowing the bone to harden in to its proper position.
The next step may require the application of braces on the top teeth, during or after expansion. This treatment will close the common “gap-tooth grin” that develops during the upper-jaw expansion. The patient may finally need to continue wearing braces for one to two years after expansion is completed.