Frequently Asked Questions About Crossbites

Orthodontists treat a number of malocclusions, or problems with the way a person’s teeth align when the jaws are closed. Crossbites are one example, and they’re fairly common. If you suspect your child has this dental condition, or you’ve recently been given the diagnosis, below is some introductory information about crossbites to help you understand what’s going on, why treatment is important, and what the options are.

What Is a Crossbite?

Crossbites can affect just a single tooth, or a group of teeth. There are two types of crossbites:

A posterior crossbite is when the upper teeth sit behind the lower teeth when the jaw is closed. This is similar to the malocclusion called an underbite; the difference is that with an underbite, all the upper teeth fit behind the lower teeth, while only one of some of the upper teeth are misaligned with a posterior crossbite.

An anterior crossbite is when the lower teeth sit behind the upper teeth when the jaw is closed. This is similar to the malocclusion called an overbite; the difference is that with an overbite, all the lower teeth fit behind the upper teeth, while only one of some of the lower teeth are misaligned with an anterior crossbite.

Is a Crossbite Concerning?

Crossbites are certainly a cosmetic issue, but they can also cause discomfort, pain, and complications. Chipped or worn teeth are a concern, as are damaged and receding gums, which can be painful and lead to gum disease. Crossbites can also make chewing or speaking more difficult, and they can trigger jaw pain, neck pain, shoulder pain, headaches, and temporomandibular joint (TMJ) disorders. Other concerning things about crossbites are that they can lead to impaired or lopsided jaw growth in growing kids and teens, and potentially contribute to sleep apnea.

What Causes a Crossbite?

In some instances, a crossbite is just a result of the way certain teeth grow in. Other times, the malocclusion stems from the natural position of the jaw. And sometimes both factors are in play. Genetics are often a factor, but delayed loss of baby teeth and growth of adult teeth can also lead to a crossbite. Behavioral factors can also cause a crossbite, such as mouth breathing and prolonged thumb sucking in early childhood.

How Is a Crossbite Treated?

In many cases—in kids and adults—crossbites can be treated with braces or clear aligners. This is generally accomplished in 18 months to 3 years, depending on the severity of the crossbite. Dental devices like palate expanders or orthodontic headgear are sometimes used to correct a crossbite in children, too. Adults may sometimes be treated with removable palate expanders or elastics. In rare, severe cases, surgical repositioning of the jaw may be necessary.