Underbite: Lower Teeth in Front of Upper Teeth

What It Is, What Causes It, and How Braces Can Help.

An underbite occurs when the lower front teeth extend in front of the upper front teeth when the mouth is closed. This type of bite misalignment is often visible from a young age and can affect the way a child eats, speaks, and grows — both physically and socially.

In moderate to severe cases, an untreated underbite can lead to long-term issues with jaw function, facial balance, and oral health.

What Causes an Underbite?

Underbites can be caused by a combination of genetics, growth patterns, and environmental factors, such as:

A larger lower jaw or smaller upper jaw
Tongue thrusting or chronic mouth breathing
Extended thumb sucking or pacifier use
Delayed loss of baby teeth
Impacted or missing upper teeth

In most cases, the jaw grows unevenly, with the lower jaw developing faster or longer than the upper, creating the underbite.

Signs of an Underbite

You might notice:

The bottom teeth overlapping the top teeth when your child bites down
The chin appearing more prominent or “jutting forward”
Difficulty chewing certain foods
Speech issues (especially with “s” or “sh” sounds)
Jaw pain or discomfort

Underbites are often easier to correct if caught during growth. That’s why early evaluation is so important.

Why Early Treatment Matters

Underbites can worsen as a child grows, especially if the jaw imbalance continues unchecked. If left untreated, an underbite may lead to:

Uneven wear on the teeth
TMJ pain or clicking
Receding gums or bone loss
Facial asymmetry
Difficulty with chewing or speaking clearly

In severe cases, untreated underbites in adults may require surgery to realign the jaws.

How an Fix an Underbite

Treatment depends on the child’s age and the severity of the underbite. Common solutions include:

Braces with elastics to guide jaw alignment
Palatal expanders (in younger children)
Reverse pull headgear (to encourage forward growth of the upper jaw)
Tooth reshaping or extraction (in certain cases)
Jaw surgery (for non-growing teens or adults with severe underbites)

An early orthodontic consultation can determine which options are most appropriate — and often simplify treatment down the line.

Surgical Underbite Correction

Your orthodontic team at Families First Dentistry & Orthodontics will make every effort to create a treatment plan that is the least invasive and most effective. Most common issues can be corrected with a combination of braces and retainers, but certain irregularities can’t be corrected with orthodontic appliances alone.

Jaw surgery to correct an underbite or other malocclusion may be an option after growth stops, which varies from person to person. An oral surgeon can help move the jaw into a more correct position by adding or removing bone. In most cases, this type of operation can be performed from inside the mouth, leaving no visible scars.

When to Schedule a Consultation

If you notice your child’s lower teeth sitting in front of their top teeth — or if their chin appears more prominent than expected — it’s time for an orthodontic consultation. At Families First, we offer complimentary consultations that include imaging and expert treatment guidance.

Our orthodontic team will walk you through the best approach for your child’s bite, growth stage, and long-term oral health goals.

Claim Your Complimentary Consultation

Our orthodontic team is here to help with complimentary orthodontic consultations in Bluffdale, Riverton, Stansbury Park, and West Jordan. Complete the form below or call (801) 254-9700 to schedule.

Frequently Asked Questions

What causes an underbite in kids?

Most underbites are due to uneven jaw growth, but habits like thumb sucking or mouth breathing can make them worse over time.

Is an underbite a serious problem?

It can be. Untreated underbites can affect facial growth, chewing, speech, and lead to long-term jaw joint issues.

Can braces fix an underbite?

Yes — braces are often used in combination with elastics or other appliances to correct an underbite. In severe cases, jaw surgery may be necessary.

When is the best age to treat an underbite?

Around age 7 is ideal for a first orthodontic screening. Some treatments are most effective when done early while the jaw is still growing.

Is jaw surgery always required for underbites?

No — many underbites can be corrected with braces and growth-guiding appliances if caught early.