Crossbite is a form of malocclusion where a maxillary (upper) tooth, or teeth, have more of a lingual position with respect to its antagonist in the lower arch. This translates to either an edge to edge bite between the teeth or the mandibular (lower) teeth being closer to the cheek as compared to the maxillary antagonist.

Problems and Treatment of Crossbite

Dental Crossbite
Incorrect position of the maxillary and mandibular molars leads to posterior crossbite

A cross bite occurs when a tooth or teeth have a more buccal or lingual position than the opposing tooth or teeth. This means that some teeth are either too close to the cheek or lip or to close to the tongue or the palate. In an anterior crossbite the lower tooth or teeth are positioned closer to the lip than the upper tooth or teeth. In a posterior crossbite, the lower tooth or teeth are positioned closer to the cheek than their antagonist. A crossbite creates a problem because the anatomy of the teeth allow for more even distribution and dissipation of force during chewing with correct alignment.  Potential problems caused by a crossbite can include excessive wear of teeth, uneven distribution of forces during chewing, inefficient chewing, reduced chewing surface area, potential injury to the lip or cheek, and unaesthetic appearance.

An anterior cross bite is typically caused by an overgrowth of the lower jaw. Since the lower jaw is larger than the upper, the lower anterior teeth end up closer to the lip than the upper teeth. A posterior crossbite is typically seen in a patient with a narrow upper jaw and dental arch.

A crossbite is a condition that is corrected during comprehensive orthodontic treatment with the use of braces, brackets and orthodontic wires, a quad helix, clear aligner therapy and other less common ways.  If there is a significant jaw discrepancy, maxillary arch being smaller than required for correct positioning of teeth, early intervention with a palatal expander can potentially shorten future treatment time and the extent of required comprehensive orthodontic treatment. Talk to your dentist to determine when an orthodontic consultation should be completed.