Types of crossbite

Anterior crossbite ([Figure 2]) occurs when one or more of the upper incisors are in the linguo-occlusal position. Posterior crossbite occurs when the buccal cusps of upper molars and premolars overlap the lower teeth during occlusion, causing the lower teeth to overtake the upper teeth buccally. Subtypes of posterior crossbite are: Unilateral buccal crossbite with displacement, Unilateral buccal crossbite with no displacement, Bilateral buccal crossbite, Unilateral lingual crossbite and Bilateral lingual crossbite-scissor bite.

Dental evaluation

Compensated Class III malocclusion must be recognised when the incisors are in edge-to-edge relation and the lower incisors are retroclined. Along with a functional evaluation, a clinical evaluation of under jet in relation to Class III molar relation should be performed.^[8]

Functional evaluation

A functional evaluation of the relationship between the mandible and the maxilla should be done to decide whether there is any centric relation (CR) or centric occlusion discrepancy (CO).

Profile evaluation

An assessment of the facial proportions, jaw, and face positions is performed during a profile evaluation.

Cephalometric evaluation

Determine the location of the maxilla and mandible using cephalometric analysis.

Anterior crossbite management-

As part of the diagnosis, presence or absence of anterior displacement from centric relation to centric occlusion during mandibular closure must be determined. Treatment, prognosis, and stability are both affected by the differentiation between real class III and pseudo class III malocclusions.^[9]

Factors to consider when deciding on a treatment plan

What kind of movement is needed?

By the end of therapy, you can have an overbite.

Non-extraction vs. extraction cases

If the opposing tooth needed to pass over

It should be determined that what form of movement is needed for correction. Removable appliances may be used to help with tipping, while fixed appliances are used to help with bodily tooth movement. These features, as well as good anterior retention to counteract the active element's displaying influence, should be included in the appliance.^[10] A bite plane or an active part to move the teeth could be used to free the occlusion with the opposing arch([Figure 2]). When there isn't enough overbite to keep the corrected incisors in place, fixed appliances might be recommended ([Figure 3]). Straight wire mechanics may use open coil springs to build enough arch length to position the teeth. For upper incisors that are palatally located, a negative root torque is often needed. The stability of retention is dependent on an appropriate overbite and a natural inclination of the long axis of the tooth to be handled.

Correction of Anterior Crossbite in Preadolescent age group

Using a tongue blade to correct a developing crossbite is an option. A tongue blade looks like a flat ice cream stick and is positioned inside the mouth on the palatal side of an erupting tooth in crossbite. The opposite side of the tooth comes into contact with the labial part of the opposing mandibular tooth during the slight closing of the jaws. During this time, light forces can assist the tooth in achieving a better position. ^[10]

The lower inclined plane, also known as Catalan's appliance, is built at a 45-degree angle to the maxillary occlusal plane and can be cemented on lower incisors. ^[11]

Correction of Anterior Crossbite in Adolescents and Adults-

Single or multiple tooth crossbite may be handled with fixed appliances.

Temporary Anchorage Devices are nowadays used as an option to treat crossbites. ^[12]

Posterior crossbite management

A coffin spring is an omega-shaped wire appliance that is used to fix crossbite in children's teeth. The expansion is gradual and symmetrical on both sides.

Quad helix is a permanent appliance that is soldered to molar bands that are cemented to the first permanent molars. It has a sluggish expansion rate and can be used in conjunction with a fixed appliance. ^[13]

The rapid maxillary expansion appliance involves hyrax screw capable of splitting the mid-palatine suture and brings about skeletal changes in a short interval. The RME screw can be incorporated into 2 types of appliances, the banded RME and bonded RME.

NiTi Expanders are nickel-titanium wire shapes that can be welded to molar bands cemented to the maxillary first permanent molars and attached to lingual sheath. There are several sizes to choose from, depending on the amount of expansion required and the width of the palate before surgery. ^[14]

Fixed orthodontic tools, which have three-dimensional control over the tooth, may be used to correct posterior crossbite. Depending on the movement needed, the arches may be kept slightly extended or constricted. Individual tooth crossbites in the posterior segment can be corrected with cross-elastics of 3/16-inch diameter exerting a force of 2.5 to 4.5 oz. ^[15]

Potential damage from untreated cross bite

Facets may occur on the labial enamel surface of locked upper incisor.

Excessively abrasion of both upper & lower incisor is common.

Inflammation & periodontal problems of mandibular incisors.

Loss of arch dimension.

Traumatic occlusion.

If the problem persists for a period of time leads to the TMJ disturbances. ^[16]