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

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

Genetics

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.

Injury

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

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

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 study 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.

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.

Cost

According to CostHelper.com, the costs of jaw surgery to correct underbite vary by provider. In cases where dental and skeletal abnormalities in the face are causing health problems, jaw surgery may be covered by some health insurance plans.

Someone covered by health insurance might pay as little as $100 for a surgery copay, or $5,000 or more for the surgery if their insurance plan includes a cap for jaw surgery.

In some cases, health insurance companies might not cover jaw surgery if it’s not deemed surgically necessary to keep a person healthy.

Without insurance, the typical costs of jaw surgery to correct an underbite can run from $20,000 to $40,000. Costs are usually lower if surgery is only needed on one jaw.

Surgery involves an exam, X-rays, general anesthesia, bone cutting, bone reshaping, and jaw repositioning. Screws, plates, wires, and rubber bands also hold the jaw in place after surgery. It takes one to three weeks to recover from jaw surgery, and often a dentist will recommend braces or other dental appliances after surgery to keep the teeth in place.

While an underbite involves lower teeth that extend out in front of upper teeth, an overbite does the opposite. With an overbite, upper teeth extend far beyond the lower tooth line. Usually this condition doesn’t require the treatment you may need for an underbite, though it can have similar causes.

An underbite is a less common dental condition that can affect not only your self-esteem, but also your quality of life. It’s possible to treat and even fully correct an underbite. Visit a dentist to learn more about your treatment options and to determine which is best for you.