What is an underbite?

Underbite definition

Picture by Authority Dental under CC 2.0 license

It is the common term given to Class III malocclusion. The main characteristic of this condition is the protrusion of the lower teeth over their upper counterparts. Meaning that when you bite, your lower teeth are positioned in front of the upper ones instead of behind like they should.

This condition usually occurs when there’s a skeletal problem that results in a misalignment between the upper and lower jaws, such as protrusion of the lower jaw or the use of underdevelopment of the maxillary bone or upper jaw. However, in some cases, the issue is not related to skeletal problems but only teeth malposition.

Underbite does not look the same to everyone as the severity of this condition can range from mild to moderate and severe.

Although aesthetic issues may be the most obvious consequence of having underbite problems, there are more serious health problems associated with this condition.

Causes of underbite

The cause behind this malocclusion can vary from a person to another. Multiple factors contribute to the development of an underbite. Furthermore, in some cases, it could be attributed to a combination of different factors.

The most common reasons include conditions such as:

Genetics

The shape of your face, skeletal structure, and teeth are determined by your genetic. Overbite is a condition that is deeply tied to the genetic code. Moreover, it is usually inherited from your parents, and the odds of your offspring developing it are higher than the average person.

Childhood habits

Certain habits such as prolonged thumb sucking, bottle feeding for extended periods, constant use of pacifiers, and pushing on the teeth with the tongue can lead to jaw bone shape anomalies development. That is because children's bones grow at an accelerated rate and are easy to modify by external factors. It is essential to understand that these habits are only harmful when done for extensive periods.

Trauma

Same as with any other bone in your body, your jaw will try to heal if it breaks. However, in some cases, the broken portion of the jaw gets wrongly repositioned or moved through the healing process. It can cause the jaw to heal in an odd position or angle, resulting in an underbite.

Tumors and lesions

Certain tumoral growths and lesions can expand the jaw bone and change the alignment of the teeth. It is vital to attend consultation when growth has been spotted as it may require immediate attention. Although the size of the lesion does not always correlate with the danger it poses, a prompt response can make the treatment less invasive and easier to fix the underbite.

Genetic and uncontrolled habits during childhood are usually the chief causes of an underbite. However, as the development of this condition can be predicted and observed during the early stages of life, particular and timely measures can be promptly taken to prevent it from evolving and exacerbating.

How does underbite affect your health?

Underbite can have a negative impact on your overall health. Although appearance and aesthetics issues are the most obvious consequences of having this malocclusion, depending on the severity of the underbite, you could experience more dangerous consequences that may even affect your sleep quality.

Some of the underbite effects includes:

How to fix underbite?

Picture by Authority Dental under CC 2.0 license

The treatment can range from traditional orthodontics to surgical procedures, and it will depend on the severity of underbite and the age of the patient. Children can wear interceptive orthodontics, which uses bone growth as a benefit to alter its shape and fix the malocclusion in a noninvasive way.

Braces

As an adult or teenager, braces can be used to fix mild cases of an underbite. They will pull the teeth back into a better position and help realign the jaw.

The dentist will perform a thorough evaluation of the case to design the best treatment plan that enables the teeth alignment and fix the malocclusion.

Invisalign

Clear aligners work the same way as braces or traditional orthodontics in the treatment of underbite. They are used in mild cases and fix it by strengthening the teeth to help realign the jaw.

The difference relays in the system used to move the teeth. Although Invisalign and other types of clear aligners can offer a more discrete solution than braces, they both will produce the same results.

Headgear (face mask)

Headgear is a specialized appliance that possesses two support points: one on top of the forehead and one on the chin. Both supports are connected by a vertical frame. It has bands that attach to the teeth and pull the whole upper jaw forward to align it with the lower jaw properly.

This treatment works better on younger patients whose bones are still developing.

The treatment time will vary depending on the severity of the underbite. However, it lasts approximately a year, and the face mask must be worn at least 16 hours a day.

Palate expander

This removable orthodontic appliance is placed on children’s palates and works by applying outward pressure to the teeth and bone. Palate expander possesses a mechanism that allows it to manually widen using a key. Doing so promotes palate expansion, making the bone grow until the upper teeth are no longer behind the lowers ones.

Surgery

Surgical procedures are required to treat severe underbite cases. Depending on the studied case, the surgeon can perform orthognathic jaw surgery to modify the lower jaw and place it in a correct position or a Le Fort III osteotomy where the upper jaw is separated and moved forward.

Cosmetic treatment

The dentist can opt to reshape the lower teeth and design veneers for the upper ones. However, it can only be done in mild cases, and although it will improve the aesthetic aspect, it will not completely fix the underbite as the molars may also be misaligned.