Underbite: Causes, How to Fix, Symptoms, in Children

An underbite is an orthodontic problem in which lower teeth stick out further than upper teeth. 

5-10% of the world’s population have an underbite. 15% of Chinese individuals develop underbite while only 5% of US residents do, suggesting it’s at least partially a genetic condition.

Untreated underbite can affect everything from self esteem to sleep quality.

What is an underbite?

An underbite is a type of bite misalignment in which the bottom teeth jut out further than the upper teeth. An underbite is also referred to as mandibular prognathism or a Class III malocclusion. 

In moderate to severe cases of prognathism, the face can take on a “bulldog” look due to the protrusion of the bottom jawbone.

Beyond appearances, this is one of “the most severe” conditions that can occur in the jaw, teeth, and face. An underbite is known as a “bad bite” because it can be harmful to not just dental health, but overall health.

Because of the number of complications an underbite can cause, it’s vital to pursue underbite correction with the help of your dentist and/or orthodontist.

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Underbite Causes

An underbite can be caused by a number of factors, including genetic makeup, environmental factors, or other illnesses.

Genetic Factors

Underbite causes definitely include genetic predisposition. A specific genetic phenotype McKusick No *176700 seems to be responsible for underbite throughout several families of European nobility.

The most famous of these genetic issues is the famous Habsburg jaw, seen in the Spanish Habsburg family between 1516-1700.

Other inherited conditions may cause an underbite, such as:

• Treacher Collins syndrome
• Nevoid basal cell carcinoma
• Acromegaly
• Severe Binder syndrome
• Geroderma osteodysplastica
• Rabson-Mendenhall syndrome

Childhood Habits

Several habits during childhood may increase the chances of developing an underbite later in life:

• Thumb sucking
• Using pacifiers after the age of 3
• Bottle feeding after infancy
• Pronounced tongue thrust (pressing the tongue forward against the teeth) during the toddler years

Physical Injury

A broken jawbone may heal improperly and lead to an underbite. Broken jaws may not recover perfectly, even after surgery, and may have a permanent underbite.

Tumors

A cancerous or benign tumor, including those caused by nevoid basal cell carcinoma, can force the jaws to protrude.

Cleft Lip or Palate

People born with a cleft lip or palate more often develop an underbite.

How to Fix Underbite

There are 5 basic treatment options to fix an underbite:

1. Orthodontic treatment
2. Tooth extraction
3. Tooth reshaping
4. Underbite surgery
5. “Facelift” dentistry

The severity of your underbite affects the type of underbite correction your orthodontist will prescribe. 

Underbite during childhood may be treated with orthodontics. If you have an underbite caused by skeletal issues, you cannot treat your underbite without surgery. 

1. Orthodontic treatment

Orthodontic treatment, like braces or Invisalign, may fix a mild underbite. “Pseudo” class III underbite in children, where lower teeth are in front of upper teeth but jaw growth is normal, can typically be treated with braces and/or tooth extractions.

More often than not, metal braces are preferred to treat underbite in children.

Invisalign or other clear aligners for a class III underbite in children may work, but will likely require tooth extractions.

Never use at-home clear aligners for an underbite. Your orthodontist should oversee treatment to ensure the jaws are properly aligned.

Before or instead of braces, your orthodontist may prescribe headgear. A reverse-pull face mask uses metal bands attached to the upper back teeth and wraps around the head to pull the jaw into place.

Your child may also be prescribed an upper jaw expander. An upper jaw expander is a plastic and wire device fixed to the roof of the mouth and expanded by turning a key daily. Over the course of roughly a year, the palate expands to correct the bite.

Cost:

• Braces: $2,000-$8,000
• Lingual braces: $8,000-$10,000
• Clear aligners: $4,000-$7,000

2. Tooth extraction

Tooth extraction can be used to fix overcrowding that causes an underbite. Generally, lower bicuspids (premolars) are removed during extractions for underbite.

A tooth extraction may be necessary to relieve the pressure this causes and aid the jaw in relaxing into its natural position. Most of the time, this is a first step prior to braces or other treatment options.

Cost: $75-$300 per tooth

3. Tooth reshaping

Tooth reshaping is a cosmetic dentistry option for underbite marked by teeth that do not fit properly in the mouth.

In this treatment, the bottom teeth are shaved down and reshaped slightly, and veneers fitted to the upper teeth. Tooth reshaping can realign how the jaw fits together and is appropriate for some mild cases of underbite.

Reshaping teeth is relatively painless, since it only alters tooth enamel. It may also lowers the risk of tooth decay.

Cost: $50-$300 per tooth

4. Surgery

Jaw surgery (orthognathic surgery) is a treatment option that may be required for underbite in older patients or cases of a severe underbite.

Typically, jaw surgery for underbite is used in conjunction with orthodontic treatment.

Jaw surgery can realign the position of your upper and lower jaw and create proper bite patterns in extreme cases of prognathism.

Each surgery is different and tailored to the patient. Normal recovery time for jaw surgery between 10-12 weeks.

Cost: $20,000-$40,000 before insurance

5. “Facelift” Dentistry

“Facelift” dentistry aims to correct bite problems including underbite. “Facelift dentistry” uses JawTrac and VENLAY technology, which are designed to prevent the need for braces and jaw surgery.

This treatment option, available only to adult patients, claims to correct underbites in as little as 3 weeks by harnessing electronic jaw tracking readings. 

The readings are based on the projected natural position of the jaw without malocclusion (teeth misalignment).

Cost: $35,000 and up

Underbite Complications and Symptoms

Common effects of an underbite include:

• Speech difficulties
• Pain in the jaw or mouth
• Frequent headaches
• TMJ pain/TMD (pain in the temporomandibular joint)
• Earaches
• Stomach issues
• Mouth breathing
• Sleep apnea
• Bruxism
• Hypertension (high blood pressure)

An underbite is typically not a difficult condition to spot. Both its conditions and symptoms are usually clear and easy for a dentist to identify, even in younger children.

If you or your little one are experiencing any of the above issues, let your dental care provider know.

The symptoms of an underbite are, in part, determined by the severity of the malocclusion.

The most obvious symptom is a visible protrusion of the lower jaw beyond the upper front teeth. Overcrowding in the teeth and an aching jaw are also very common.

Underbite in Children

Traditionally, children with underbite aren’t treated until the age of 7. However, an orthodontic assessment between the ages of 2-5 may allow your child’s orthodontist to fix the growth issues causing the underbite before more dramatic treatment is needed.

If underbite interferes with eating, speaking, or breathing, or if your child was born with a birth defect, they may need surgery earlier than normal.

Because underbite can make dental hygiene more difficult, monitor your child’s teeth brushing and flossing. Watch for early signs of cavities or gum disease, such as bleeding gums.

Underbite vs. Overbite

An overbite (retrognathism) is an orthodontic condition where the top front teeth extend far over the lower teeth and jaw. It’s the opposite jaw positioning than an underbite, where the top teeth are behind the lower teeth.

Both an underbite and an overbite can make patients self-conscious, causing issues with breathing, chewing, and speaking.

Is underbite treatment covered by insurance?

Underbite treatment is usually covered by dental insurance if the insurance company believes the treatment is medically necessary. Keep in mind, most dental insurance companies max out between $1,000-$2,000 total coverage for the year, which may not cover extensive treatment for underbite.

If the insurance company (or your dentist) determines your underbite treatment is cosmetic, the cost is unlikely to be covered by insurance.

Orthognathic surgery for underbite is a rare case in which a dental treatment is frequently covered, in part, by your medical insurance. Your medical insurance may cover treatment for underbite if your doctor and dentist agree that it is causing airway issues like sleep apnea.

Most dental insurance does not cover Facelift dentistry.

Always check with your dental office and full dental insurance plan before treatment to avoid surprise costs. Every insurance plan and patient case is different.

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