Overbites, Underbites, and Crossbites – Understanding the Difference


You’ve heard of overbites, underbites, and crossbites; you or your child may even be suffering from one of these conditions—but how exactly do you know which is which? It may seem difficult to keep these terms straight in your head, but fortunately they aren’t difficult to straighten out with proper orthodontic care. Today we’ll be talking about each of these conditions to give you a better idea of your situation so you can start the journey to making your bite right.

What is a Crossbite?

A crossbite is a malocclusion (bite problem) where the top teeth and bottom teeth do not come together or bite in the correct position.

Crossbites can be caused by either tooth position, jaw position, or a combination of both. They can occur in the front teeth (called an anterior crossbite or underbite) or in the back teeth (called a posterior crossbite).

How is a crossbite treated?

In kids and teens, posterior crossbites (crossbites in the back teeth) are often times treated by broadening the upper teeth and jaw. This can be done with special appliances or braces depending on the person.

In some teens and adults, crossbites can be treated by braces or Invisalign treatments.

Crossbites of front teeth are many times treated with braces or special retainers.

In rare cases, crossbites are so severe that jaw surgery may be needed.

What is an Overbite and How is it Corrected?

There’s something pleasing to the eyes about a clean, white and perfectly aligned teeth. Turn on the TV, flip open a magazine or head to the movies and you’re inundated with flawless smiles. But not everyone is so fortunate: many kids and adults suffer from a malocclusion, one type of which is an overbite. Before considering methods of overbite correction, let’s take a look at what the condition is and the reasons it may occur.

What causes an overbite?

The most common cause of an overbite is the shape and/or size of the jaw or the teeth. This could mean having too much room in the jaw area or too little room to accommodate one’s teeth. If not treated, the overbite will allow the teeth to crowd each other and grow in crooked if there is too little room, or the teeth will be spaced too far apart if the jaw area is too large. In infants and children, habits like thumb-sucking, sustained and consistent pacifier use and overuse of a bottle, which causes pushing the tongue against the back of the teeth, can produce an overbite. In teens and adults, chronic nail-biting and chewing of objects such as pencils or other items can cause an overbite. According to the American Dental Association, nearly 70 percent of children exhibit the signs of having an overbite. Other causes are:

What happens if I don’t treat it?

If left untreated, an overbite could cause significant health complications. These include irreparable damage to teeth from abnormal positioning and possible jaw pain including temporomandibular joint disorders (TMJ). Other overbite complications include:

  • Tooth decay including cavities, gum disease, and worn tooth enamel
  • Jaw pain
  • Severe headaches
  • Discomfort or pain while eating
  • Trouble with fully opening or closing mouth
  • Sleep apnea
  • Difficulty speaking

An untreated overbite could also dramatically alter the facial structure and lead to issues like low self-esteem. If an overbite in early childhood is severe, and continues to worsen, aesthetic deterioration could take place as early as pre-pubescence.

How do I treat and correct an overbite?

Generally, a dentist will refer a patient with an overbite to an orthodontist for treatment. In children, they are easier to treat because a child’s jaw is still in the developmental stages. For children and teens, the most common issue is crowding of teeth in the mouth. For many adults with an overbite problem, the lack of preventative treatment early in life has led to the more severe symptoms associated with overbites. In either case, the orthodontist or dentist will examine the area and write up a treatment plan that can last for up to two years and possibly longer. Initial x-rays will be taken to determine the type of overbite and the relationship between the teeth and the jaw in determining the best treatment. Here are some treatments your orthodontist or dentist may recommend to correct an overbite issue:

Children and Teens

  • Removal of baby teeth (making room for permanent teeth to grow in straight)
  • Growth modification device (used best during growth spurts) – helps to better position the jaw
  • Braces – slowly moves the teeth to correct the overbite as well as the jaw
  • Retainers – device used post-braces that help to keep the teeth in place


  • Braces – move only the teeth to correct an overbite
  • Teeth removal – dentists and orthodontists try to avoid this procedure but will do this in very severe overbite cases to allow the teeth more freedom to move.
  • Surgery – jaw problems for skeletal-type overbites can only be corrected with surgery for adults.

If your overbite is causing issues, it’s important to make an appointment with your orthodontist or oral surgeon for treatment. In any case, for both children and adults, the best way to prevent dental issues from occurring is to make sure you visit a dentist early and often. It is recommended for children to get a checkup by age 7 for the detection of an overbite. Adults need to get regular checkups every six to twelve months to ensure early intervention and avoid the potentially severe physical repercussions of leaving an overbite untreated.

What is Underbite?

An underbite is a term for a dental condition characterized by lower teeth that extend outward farther than the upper front teeth. This condition is also called a Class III malocclusion or prognathism.

It creates a bulldog-like appearance in the mouth and face. Some cases of underbite can be severe, causing the lower teeth to extend far forward. Other cases are milder and nearly unnoticeable.

An underbite is more than just a cosmetic issue. While some people may learn to live with mild cases, severe cases may cause oral health problems, such as:

  • difficulty biting and chewing food
  • challenges with speaking
  • mouth and face pain due to misalignment of the jaw
  • Underbite causes

The way your teeth align may be affected by several factors. Normally, teeth grow in such a way that upper teeth fit a little over the lower teeth. Your molars — the flat, wide teeth at the back of your mouth — should fit into one another. Proper tooth alignment keeps you from biting your cheeks, lips, or tongue when you eat.

There are several factors that could cause a person to develop an underbite. These include:

Childhood habits

Some childhood habits may increase risk for developing an underbite or other dental misalignment. Contributing factors to an underbite include:

  • thumb sucking
  • pushing on teeth with the tongue
  • pacifier use in children above age 3
  • long-term feeding from a bottle beyond infant years


Most often, an underbite is inherited. You’re more likely to develop an underbite if at least one other person in your family also has it. Genetics also decide a person’s jaw and tooth shape and size.

Someone may be born with teeth very close together, impacted, abnormally shaped, or that don’t fit together properly. Certain defects such as a cleft lip or palate may also appear at birth. All of these conditions can sometimes result in malocclusion.


Severe injuries to the face may cause permanent damage to the jawbones. Often, it’s possible to repair broken jawbones, but jaws don’t always fit together properly after being surgically realigned. This can cause underbite.


Tumors on the jawbones or in the mouth may cause the jaws to protrude, causing an underbit

Underbite treatment

Most people aren’t born with perfectly aligned teeth. Usually, slightly misaligned teeth don’t require any medical treatment. However, correcting an underbite, especially when it’s severe, can have big benefits.

Teeth will become easier to clean. Your risks for tooth decay and gum disease will decrease. You’ll also feel less strain on your teeth, jaws, and facial muscles. This can reduce your risks of breaking a tooth and also painful symptoms of temporomandibular disorders, which are common with underbites. Some common treatments for underbite include:

At-home treatment

Brushing and flossing your teeth regularly in addition to visiting a dentist for checkups and cleanings are important parts of treatment for healthy teeth. But those with an underbite or other dental issues must take special care of their teeth to prevent further damage and decay.

Brush your teeth at least twice a day for two minutes each time with toothpaste containing fluoride. Pay attention to brushing along your gumline and on the inside, outside, and the back of your mouth. Be sure you floss in addition to brushing. See your dentist at least twice a year for checkups and cleanings.

Medical treatment

Medical treatment is the only way to truly correct an underbite and align teeth correctly. At the very least, medical treatment can improve the appearance of an underbite.

In less severe cases of underbite, a dentist may be able to use wire or plastic braces or other dental appliances to move the teeth into their correct place. Removal of one or more teeth on the lower jaw may also help improve the appearance of an underbite if overcrowding of the teeth is contributing to the issue. A dentist may also use a grinding device to shave down or smooth teeth that are large or stick out.

In more severe cases of underbite, a dentist may recommend surgery to correct the condition.

Underbite for toddlers and children

The earlier an underbite is addressed, the better. If a child’s underbite is less severe, parents should wait until at least age 7 to seek corrective treatment such as braces. That’s when permanent teeth begin to erupt.

For short-term correction, a small studyTrusted Source suggests facemask appliances can help ease lower front teeth into place in children. But they’ll still require a more permanent solution later in life.

If your child has a severe underbite, especially if it’s caused by a birth defect such as cleft lip, early surgery may help. Talk to your child’s dentist and doctor to see what course of treatment they recommend. Surgery has its risks and should only be used in children when underbite is interfering with their quality of life or ability to eat, breathe, or speak.

Underbite surgery

Most certified oral surgeons are able to successfully correct underbites. Several common types of surgery to correct underbite include reshaping to lengthen the upper jaw or shorten the lower jaw. In some cases, the use of wires, plates, or screws may maintain proper shape of the jawbone. Surgery comes with several risks, including those associated with general anesthesia, infection, bleeding problems, and scarring.






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