Underbite: Causes, Symptoms, and Treatment Options

An underbite is a bite issue that affects an estimated 5–10% of people worldwide. It occurs when the lower teeth or jaw sit in front of the upper teeth, and while it may seem like a purely cosmetic concern, an untreated underbite can affect your oral health, comfort, and quality of life.

This article explains what an underbite is, why it happens, when it may need treatment, and what your options are. An orthodontist can evaluate the severity of your underbite and recommend the right treatment plan for your specific situation.

What Is an Underbite?

An underbite is a type of malocclusion, a clinical term for teeth and jaws not lining up the way they should. In a healthy bite, the upper front teeth sit slightly in front of the lower teeth when you close your mouth. With an underbite, that relationship is reversed — the lower front teeth end up overlapping or sitting ahead of the upper front teeth.

Underbites range from mild (barely noticeable) to severe (where the lower jaw visibly juts forward). The cause can be:

• Dental — a tooth positioning issue
• Skeletal — related to jaw structure
• A combination of both

That distinction matters a lot when it comes to figuring out the best treatment approach.

Common Signs and Symptoms of an Underbite

Some underbites are obvious at a glance. Others are subtle enough that only an orthodontic exam will catch them. Common signs include:

• Lower teeth that sit visibly in front of the upper teeth when biting down
• A lower jaw or chin that appears more prominent than the upper jaw
• Difficulty biting or chewing comfortably
• Speech issues, like a lisp or trouble pronouncing certain sounds
• Jaw discomfort or pain, especially around the joints
• Uneven or accelerated tooth wear
• Difficulty closing the mouth fully without strain

If any of this sounds familiar, it’s worth getting an orthodontic evaluation to understand what’s going on and whether treatment makes sense.

Factors That Can Influence How the Teeth and Jaws Develop

A variety of factors can affect the way the teeth and jaws develop, including:

• Genetics. Jaw shape, size, and bite patterns tend to run in families. Some people are simply born predisposed to an underbite.
• Jaw development differences. If the upper jaw grows more slowly than the lower, or the lower jaw grows more than expected, the teeth can end up out of alignment.
• Childhood habits. Prolonged thumb sucking, extended pacifier use, tongue thrusting, and chronic mouth breathing can all influence how the teeth and jaws develop during the early years.

How Is an Underbite Diagnosed?

An orthodontist evaluates an underbite by looking at the full picture: teeth, bite, jaw position, and facial structure together. The process may include:

• A clinical exam to assess how the teeth fit together and how the jaws align
• Digital X-rays to evaluate bone structure and tooth roots
• Photos, 3D scans, or impressions to capture the complete bite

From there, the orthodontist determines whether the underbite is primarily dental, skeletal, or a mix of both. That classification directly shapes which treatment options are most likely to work.

Underbite Treatment Options

Treatment depends on your age, how much jaw growth remains, and how severe the underbite is. Here’s an overview of the most common approaches.

Braces

Braces are a reliable choice when the underbite is primarily related to tooth positioning. They apply steady, controlled pressure to gradually shift teeth into better alignment. In many cases, braces are paired with elastics or other appliances to help guide jaw position.

Clear Aligners

Clear aligners can work well for mild underbites where the issue is largely dental rather than skeletal. Because they move teeth incrementally, they tend to be best for patients whose bite can be improved through tooth movement alone. Your orthodontist can assess whether aligners are a good fit for your specific case.

Palatal Expanders In Combination with Reverse-Pull Headgear

For children who are still growing, early treatment can be effective. When an underbite is related to jaw development, a palatal expander may be used along with reverse-pull headgear to encourage forward growth of the upper jaw and improve jaw alignment. Because children’s bones are still developing, growth-guiding treatment can help address skeletal issues before they become more severe. The American Association of Orthodontists recommends that children receive their first orthodontic evaluation by age 7, as early intervention can reduce the need for more complex treatment later.

Jaw Surgery

When an underbite involves a significant skeletal discrepancy, meaning the jaws themselves are substantially out of position, orthodontic treatment alone may not be enough. In those cases, orthognathic surgery (jaw surgery) may be recommended. It’s typically performed after the jaw has finished growing and is almost always combined with orthodontic treatment before and after the procedure.

Can an Underbite Be Fixed Without Surgery?

For many people, yes. Mild underbites, when caught early, are often treated successfully without surgery. Surgery is generally reserved for more severe skeletal cases in adults where jaw structure can’t be corrected through tooth movement alone.

The only reliable way to know what applies to your situation is a thorough orthodontic evaluation.

Underbite Treatment for Children vs. Adults

Children tend to have more options available because their jaws are still growing. Growth appliances can guide jaw development in ways that aren’t possible once the bones have matured. An early evaluation, ideally by age 7, gives orthodontists the best chance to catch issues and intervene at the right time.

Adults can absolutely receive underbite treatment and get excellent results. More severe cases may involve a more involved plan since jaw growth is complete, but it’s never too late. Adults are successfully treated for underbites every day.

Visit an AAO Orthodontist to Address Underbite Concerns

Underbites are common, well understood, and very treatable. But the right approach is different for every person, which is why an evaluation from a qualified orthodontist matters.

If you’re concerned about an underbite, whether it’s your own or your child’s, don’t put it off. Find an AAO orthodontist near you and schedule your consultation today. An AAO orthodontic practice can evaluate the bite, walk you through your options, and recommend the next step that makes the most sense for your situation.

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