Crossbite: Symptoms, Diagnosis and Treatment

What is an Crossbite? How To Diagnose, Treatment Methods, and More

Are your teeth misaligned? You may have a crossbite. Crossbite – sometimes called an underbite – is a form of malocclusion, or bad bite, that results in rows of teeth that overlap improperly.

Rather than a proper bite, where the top teeth fit snugly over the bottom teeth with a very slight overbite, a crossbite or underbite occurs when the bottom teeth stick out past the top teeth, either in the front teeth or the back teeth.

There are a variety of different kinds of crossbites and underbites. This guide will help you understand what a crossbite is, the signs to look for in diagnosing a crossbite, and how to treat it. Quality orthodontic care from a licensed, experienced orthodontist can help you achieve a great smile and a proper bite.

Read on to get answers to all your crossbite questions.

What is a Crossbite?

A crossbite occurs when one or more of the bottom teeth sticks out past the top teeth.

There are two types of crossbites: anterior and posterior.

Anterior Crossbites

Anterior crossbites occur when the front bottom teeth stick out further than the front top teeth. The front teeth are the four incisors and the canines on each row of teeth. Anterior crossbites affect about 4-5% of the population. They can be treated with orthodontic care, but for severe cases in adults, some crossbites require a combination of orthodontic care and surgery to set back the lower jaw and achieve optimal results.

Posterior Crossbites

Posterior crossbites are an improper bite in the back of the teeth: the back bottom teeth (the premolars and molars) jut out further than the top bottom teeth. The crossbite may occur on only one side of the mouth, or both sides. Posterior crossbites are more common, affecting roughly 16% of the population, and can also be corrected with a common orthodontic appliance called an expander.

Underbite vs. Crossbite

An underbite is another way to describe a crossbite – the bottom front teeth protrude past the top teeth, creating an improper bite, or underbite. In a healthy smile with a correct bite, there is a very small overbite: the top teeth slightly overlap the bottom teeth, and all the teeth connect when the bite is closed. With an underbite, the reverse is true, leading to malocclusion, or a bad bite. The underbite may occur in the front teeth (anterior crossbite), back teeth (posterior crossbite), or both.

Overbite vs. Crossbite/Underbite

In a healthy bite and a well-aligned smile, there will be a small overbite: the top teeth will overlap the bottom teeth, and the rows of teeth will fit together comfortably when the bite is closed.

With a crossbite, the opposite is true: the bottom teeth stick out past the top teeth. This may be true of just a single tooth or a whole section of teeth.

Overbites may be too deep and require correction; crossbites must also be corrected.

overbite vs Crossbite

What Causes a Crossbite?

There are two main causes of crossbites or underbites, genetic causes, and developmental causes.

Like other physical features, teeth alignment and jaw structure are inherited traits. Crossbites are hereditary, so if a parent, grandparent, or other relative has a crossbite, there is a good chance a child will inherit a similar condition.

There is no way to prevent children from inheriting crossbites, but they can be effectively treated with orthodontic care from an experienced, licensed orthodontist.

Various factors during dental development can cause a crossbite, including:

  • Thumb-sucking
  • Mouth breathing
  • Tongue-thrusting
  • Prolonged use of a pacifier or bottle
  • Losing the baby teeth too early
  • Growing the adult teeth

All of the above can contribute to the development of a crossbite. For that reason, dental experts recommend children see an orthodontist beginning at age 7, so the orthodontist can monitor the growth of their adult teeth and determine any potential issues that may arise with their teeth and bite.

Is a Crossbite Bad for Your Teeth?

Yes. If left untreated, crossbites can cause significant damage to your health over time:

  • Headaches, toothaches, or jaw aches
  • Pain when chewing or biting
  • Trouble closing your mouth properly
  • Speech impediments such as lisp or slurs
  • Poor sleep quality
  • Temporomandibular disorder (TMD)
  • Pain in jaw joints or muscles
  • Difficulty maintaining proper oral hygiene
  • Bacterial growth
  • Plaque build-up
  • Cavities
  • Gum or periodontal disease
  • Tooth loss

Crossbites or underbites are treatable with careful intervention from an experienced orthodontic doctor. Children should see an orthodontist as early as age 7, to determine future growth patterns and make any necessary interventions for the development of healthy smiles.

A proper bite and a healthy smile are key to overall health: get expert orthodontic care from licensed, experienced orthodontists to achieve the healthiest teeth possible for a lifetime of good outcomes for your whole body, your confidence, and your life!

How to Treat Crossbites

Crossbites can be treated with orthodontic intervention. If you are concerned about your crossbite or underbite, schedule a consultation with a licensed orthodontist. They will do thorough examinations, including x-rays, to determine your specific condition, and help you choose a treatment plan that works for your preferences, lifestyle, and budget.

There are a variety of treatment options for correcting a crossbite.

Adult Braces Patient Smiling with Silver Bands


Metal and ceramic braces are both effective for treating crossbites or underbites. Using brackets on each individual tooth, connected by a wire, your orthodontist will carefully and skillfully move each tooth into its correct alignment, moving the misaligned teeth until the bite is proper.

Braces are easy, effective, and comfortable, and a great treatment option for kids, teens, and adults of all ages. They offer quick treatment times with excellent, predictable results, and their widespread use has made them one of the most affordable orthodontic treatment options.

Person Holding Invisalign Aligner with Case

Invisalign Clear Aligners

Invisalign treatment is an extremely reliable, effective method for correcting crossbites when used by an experienced orthodontist. (Remember, Invisalign is a tool and only works in hands of an experienced professional doctor).

Since they first started creating healthy smiles over 20 years ago, Invisalign clear aligners have gained in popularity for their ease of use and discreet, subtle appearance. Invisalign treatment has helped many people correct their crossbites, and can certainly help you!

Invisalign aligners are custom-created by your orthodontist for each patient’s unique case,  so when you choose Invisalign to correct your crossbite or underbite, your orthodontist will use 3D modeling to create a custom set of aligners designed to safely and effectively align your teeth into the proper position.

The clear aligners are removable, allowing you to eat or drink whatever you want during treatment, and are nearly invisible when worn, so you can achieve a beautiful, healthy smile without disrupting your appearance.

Elizabeth, 18 years old, Crossbite (upper left lateral incisor) correction in 9 months with Invisalign Treatment

Elizabeth, 18 years old, Crossbite (upper left lateral incisor) correction in 9 months with Invisalign


Expanders are an orthodontic tool used in children to expand the upper arch. The expander appliance is used to correct a developing posterior crossbite and facilitate healthy, proper growth of the teeth. Since children’s teeth, bones, and palate are all still developing, this is the best time to intervene and redirect growth in a healthy direction. If the child’s upper arch is constricted, this will likely lead to malocclusion, particularly a posterior crossbite.

The expander helps open the upper arch and make room for all the growing teeth. Expanders are very safe, comfortable, and effective when used as a tool in the hands of an experienced orthodontist. It is not visible when your child smiles, and they will likely not notice it at all once it is fitted on the roof of their mouth

Oral Surgeon Performing Dental Surgery

Oral Surgery

For very rare cases, the crossbite may be so severe that oral surgery will be required to help re-align the teeth. Your orthodontist may refer you for oral surgery.  You may be referred for oral surgery prior to beginning orthodontic treatment, or during treatment. Orthodontic treatment will then continue after surgery, and the orthodontist will complete the case and provide a retainer to protect the results of the full treatment.

Jay, 23 Years Old, Surgical Case

Initial Smile and Profile

Jay, 23 Years Old, Crossbite Surgical Case Initial

Before Surgery

Jay, 23 Years Old, Crossbite Surgical Case Before Surgery

Final Smile and Profile After Surgery

Jay, 23 Years Old, Crossbite Surgical Case After Surgery


Retainers are used post-treatment to protect the results of your orthodontic care. After your orthodontist has moved your teeth into their proper positions, you will be given a set of retainers to wear at night and keep your teeth in their new, correct places.

Make sure to wear your retainers as instructed – you want your healthy bite and beautiful smile to last, to keep you healthy and your confidence high for a lifetime.

Crossbites: Before & After Orthodontic Treatment

Manuel, 18 Years Old,  Crossbite Surgical Correction, 24 Months Treatment

Before Treatment

Manuel, 18 Years Old, Crossbite Surgical Correction, Before Treatment

In Progress

Manuel, 18 Years Old, Crossbite Sugical Correction, In Progress Treatment

After Treatment

Manuel, 18 Years Old, Crossbite Surgical Correction, After 24 Months Treatment

Tingting, 35 Years Old,  Crossbite, 20 Months Invisalign Treatment

Before Treatment

Tingting, 35 Years Old, Crossbite, Before Invisalign Treatment

After Treatment

Tingting, 35 Years Old,  Crossbite, After Invisalign Treatment

Carlos, 18 Years Old, Front and Back Crossbite, Before and After Treatment with Braces

Frequently Asked Questions About Crossbites