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What to Know About Underbite

Medically Reviewed by Dan Brennan, MD on April 28, 2021

Your teeth can have a big impact on your overall health and well-being. Having a row of straight, white teeth can raise your self-esteem and confidence. But teeth don’t always grow straight. It can take work and time to achieve straight teeth. In some cases, it might not just be your teeth that need straightening. 

The way your jaw sits can play a role as well. Your jaw has an upper part and a lower one. An underbite is when the lower part of your jaw juts out farther than the upper part. It can be uncomfortable, causing problems with chewing, digestion, and other conditions.

What Is Underbite?

An underbite is a dental condition where your lower teeth extend farther than your upper teeth. Usually, it results from a misalignment of the jaw. This is known as a Class III malocclusion.

Not all underbites are the same. There are different levels. In a mild case, you might not be able to detect it from the outside. In severe cases, the jaw protrudes outward so far that it can be noticeable to others.

Underbites are more than a basic cosmetic issue. They can cause problems with your teeth and jaw. In severe cases, you might even have trouble speaking properly. An underbite can cause wear and tear on your front teeth. This makes them more prone to chipping or breakage. You might also struggle with chewing food when your jaw isn’t aligned properly.

People with underbites might be self-conscious about the condition. This can harm someone’s self-confidence and social life.

How Underbite Can Affect Your Health

An underbite can affect your health in several ways. Not only can it take a mental toll on you, but it can even influence the way you sleep. Underbite can also affect you in the following ways.

Temporomandibular Joint Disorder (TMD). Underbite can cause problems with your temporomandibular joint. This is the hinge that connects your skull to your jaw. When you have TMD, it might feel like it’s locked in one position. You might hear a popping sound as you try to move it. This can be painful. 

Chronic bad breath (halitosis). An underbite can cause a bacterial infection to develop in the mouth. This can cause bad breath.

Mouth breathing. Heavy snoring and mouth breathing can also be caused by underbite.

Sleep apnea. Sleep apnea is a condition where you stop breathing at different points throughout the night. You don’t sleep well with this condition. That means it can cause you to be fatigued during the day.

Causes of Underbite

There are a few different reasons you might develop an underbite. 

Genetics. The shape and size of your teeth and the way they grow are largely inherited from your parents or relatives. If someone else in your family has had an underbite, it’s likely a genetic condition.

Injury. Trauma or injury to your jaw can cause it to break. There are treatments to help it heal back to its original state, but they might not always work. If your jaw doesn’t heal right, this can cause an underbite.

Bad habits in childhood. Extended behaviors like sucking the thumb, using a pacifier or dummy nipple, and bottle feeding can cause the jaw to change shape. These behaviors are fairly common for children. They don’t often cause issues if they’re done in moderation.

Tumor. The growth of a tumor can shift or misalign your jaw. This can lead to an underbite.

Underbite Treatment

Luckily, most underbites can be treated using ordinary orthodontic methods. Some cases may require surgery.

Treatments are often most successful when they’re done during childhood and the pre-teen years. The jaw is somewhat moldable when it’s still growing. Adults can be successfully treated for underbite, but treatment often involves surgery. The treatment you’ll need to correct your underbite depends on how severe it is.

Braces. In mild cases of underbite, braces can help straighten your teeth and realign your jaw. An orthodontist will assess your case and apply braces. You may have to wear a retainer afterward to help keep the new shape.

Facemask therapy. As the name suggests, a facemask is a device that is worn on your face. It rests on your forehead and chin. Elastics are attached to your upper jaw and then to the device. The idea is to pull your upper jaw forward to realign both the upper and lower sections.

This treatment requires commitment. The facemask typically needs to be worn for 16 hours per day for about a year. It’s most successful with children aged 8 and under. It can also work well for teenagers.

Elastics. Elastics treatment has the same premise as facemask therapy. Elastics are attached to mini-plates that are anchored in the skull. The elastics are worn inside the mouth and pull the upper jaw forward to create balance.

Surgery. Surgery is a solution in severe cases of an underbite. It can correct the sleep apnea caused by underbite, realign your jaw, and relieve pain. Surgery is usually only performed after you’ve stopped growing.‌

WebMD Medical Reference

Sources

SOURCES:

‌Cleveland Clinic: “Braces & Retainers.”

KOCH ORTHODONTICS: “Everything You Need to Know About Underbite.”

‌MAYO CLINIC: “Jaw surgery.”

‌Meadows Orthodontics: “Orthodontic Treatment for Underbites (Class III relationships).”

‌MedStar Washington Hospital Center: “How Corrective Jaw Surgery Can Cure Sleep Apnea and Enhance Appearance.”

‌Orthodontics Australia: “Causes of Underbite and Correction Methods.”

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