What is a crossbite and how is it treated?

A crossbite is a common problem, and one of the most common types of dental malocclusion that dentists see in their patients. It can cause physical changes in the jawline, asymmetry in the face. It can also lead to problems with chewing, the gums and bruxism.

We'll also cover possible treatments to correct this type of maloclussion in adults and children. Read on to learn about different types, causes and problems.

What is dental crossbite?

Let's start by clarifying what crossbite is. This type of malocclusion, also called 'reverse bite' is another name for when the arches of the upper and lower teeth overlap.

What is a correct bite?

In a correct bite, the teeth of the upper arch bite slightly outside those of the lower arch. Therefore, when the opposite occurs we refer to it as a case of crossbite. When teeth and jaws don't align correctly, it can affect a single tooth, several teeth or all of them.

Different types of crossbite

Depending on the part of the mouth where the occlusion problem occurs, you can identify different types of crossbite. Below we will look at the different types of malocclusion that exist:

Types of crossbite according to where it occurs

The first way that different types of crossbite can be classified is according to the part of the mouth in which the malocclusion is located. According to those classifications, there are several crossbites including: an anterior crossbite, posterior crossbite, unilateral or bilateral.

Anterior crossbite

The first type of crossbite according to where the malocclusion occurs is anterior crossbite. This type of crossbite affects the area around the incisors (i.e. the front of the mouth) and is therefore the most visible.

Posterior crossbite

Posterior crossbite is a malocclusion that affects the teeth at the back of the oral cavity (i.e. the premolars and molars). This type of crossbite is less visible than an anterior crossbite, as it occurs in the teeth at the back of the dental arch.

Unilateral crossbite

In cases where the malocclusion affects only one side of the mouth, either the right or the left, we are talking about a unilateral crossbite. This type of maloclussion can cause an asymmetrical jaw. The asymmetry may be visible in the face, as the jaw is deviated towards the side of the crossbite.

Bilateral crossbite

A bilateral crossbite occurs on both sides of the mouth. In other words, the teeth of the upper arch are located inside the teeth of the lower arch on both sides.

How do you get a crossbite?

Let's look at the different types of origin for this maloclussion type.

Skeletal crossbite

In instances where the crossbite is caused by a bone development problem, these are referred to as skeletal crossbite. In these cases, the upper jaw has not developed correctly and is therefore smaller than the lower jaw, allowing the upper teeth to remain inside the lower teeth.

Dental crossbite

There are some cases of crossbite in which the origin of the malocclusion is not underdevelopment of the jaw, but rather malposition of the teeth. These cases, where the crossbite is caused by dental malposition, are called dental crossbites. It sometimes occurs when baby teeth remain alongside adult teeth.

Mixed crossbite

Finally, there is a third type of crossbite according to origin, in which neither the bones have developed correctly nor the teeth have erupted optimally. The origin of the malocclusion is therefore mixed.

What causes a crossbite?

The causes of crossbite can vary, although in most cases they can be classified into two main groups: acquired habits or genetic factors.

Among the genetic causes of crossbite, the most common are maxillary hypoplasia and mandibular hyperplasia. In these cases, an assessment should be carried out on family members to find out the origin.

On the other hand, bad habits, such as mouth breathing, thumb sucking or incorrect tongue placement, are also possible causes of crossbite, as they affect bone and dental development.

Crossbite consequences: physical or functional problems

Crossbites can have various consequences that can lead to physical or functional problems in people who suffer from them. Among the most common problems that can be caused by crossbite are the following:

• Tooth wear and, if left untreated, one of the problems caused by crossbite can be tooth loss.
• Functional difficulties, such as problems with phonation or chewing, which can lead to digestive issues.
• Problems in the temporomandibular joint (TMJ), which can cause bruxism or jaw, head or neck pain.

Treatment for crossbite

As previously explained, crossbites can cause problems in the daily lives of those who suffer from them, so it's important to diagnose and initiate correction as soon as possible.

Treatment for crossbite in children

The most opportune time for successful treatment to modify bone growth, correct crossbite in children and avoid problems in adulthood is between the ages of 6 and 12.

Interceptive orthodontics is the most suitable treatment for crossbite in children. At this stage, when the bones are much more malleable, treatment with interceptive orthodontics, such as palatal expanders makes it possible to fix the crossbite. Expanders allow the size of the maxillary bone to be modified and the palate to be widened.

This type of treatment for crossbite is only effective in children, as once the bones are fully developed, we cannot intervene or modify their growth.

How to correct crossbite in adults

Crossbite correction in adults is more complicated than it is in children, as the bones have finished growing and are fully developed.

The first step in correcting a crossbite in adults is to see a dentist, who will examine you and determine the best treatment. There are two ways to correct crossbite in adults: orthodontics or surgery.

Crossbite correction surgery

There are cases of severe crossbite in adults or those with a skeletal origin that require surgery to correct them. On these occasions, when there is a large mandibular deviation or a very narrow palate, surgery is the only effective treatment to correct the crossbite, as the person's development is complete and it would, therefore, be impossible to amend the position of the bones with orthodontics.

Can clear aligners fix crossbite

Crossbite surgery corrects the size and position of the jaw bones to balance the aesthetics of the face and improve the functionality of the mouth. In most cases, crossbite correction surgery is complemented with a second phase of orthodontics to fix the dental malposition and achieve an aligned smile.

Orthodontic treatment: crossbite correction in adults without surgery

For cases of crossbite in adults with dental origin, orthodontics, whether fixed like braces or using clear aligners, can be an effective treatment for correction without surgery. These devices allow the malocclusion to be modified and the crossbite to be fixed.

Impress treatments for cases of crossbite

At Impress we can help to treat crossbite problems with orthodontics, whether in children, adolescents or adults.

For children, we analyse the case and design a personalised Impress Kids treatment plan to correct crossbite in the youngest members of the family.

If the case to be treated is of dental origin in adolescents or adults, we have various orthodontic solutions available. Treatments with Impress clear aligners are suitable for fixing cases of crossbite efficiently and discreetly.

If you would like us to examine your case and propose the best solution for you, our team of experts is at hand to help you achieve good oral health and perfect occlusion.

Get in touch with your nearest Impress clinic and book an appointment online, by phone at +44 20 3808 1072, or via WhatsApp.

Updated: June 2025