Did My Child Get Their Under Bite From Me?


Orthodontic abnormalities characterize by teeth misalignment and jaw displacements or clinical malocclusions. These conditions vary depending on the causes, their severity (types), and especially the problems they present to patients and treatment planning.

In general terms, occlusion refers to teeth alignment at the bite. A precise occlusion occurs when the upper and lower grooves match the points of the corresponding molar at bite.

Furthermore, the prefix (mal) derives from the Latin voice “malus,” which means bad, wrong, or inadequate. Therefore, malocclusion is an inadequate occlusion, and orthodontic treatment seeks to prevent and correct these abnormalities.

Malocclusion causes include genetics (hereditary factors), a difference in the size of the jaws, or the size of a tooth that might not correspond with the jaw. Other causes include congenital disabilities (cleft lip and palate) and extra, lost, impacted, or oddly shaped teeth.

All the detailed factors share a common background; they cannot be prevented and require a corrective approach with orthodontic appliances to restore the proper functionality of the occlusion.

However, parents could help prevent some cases. For instance, thumb sucking, tongue thrusting, using a pacifier or a bottle after year three, wrongly attached dentures or orthodontic appliances, jaw fractures, and mouth tumors.

Malocclusions characterize by their class or type. This means different abnormalities produce different forms of the mouth structure. This is especially evident when a patient smiles.

The first malocclusion type is in grade, less aggressive. Upper teeth minimally overlap the lower teeth. It is evident when people smile with their teeth touching each other, and the upper teeth cover the lower teeth slightly further than expected.

Retrognathism is the clinical term for type two malocclusion. A less technical term frequently used is overbite. The upper jaw significantly overlaps the lower jaw. The mandible doesn’t match the maxilla as it is backward.

The most prominent malocclusion is prognathism. This third type of abnormality, known as an underbite, is characterized by a protruding lower jaw (mandible). This means the lower jaw (mandible) and teeth are mispositioned in front of the upper jaw (maxilla).

This article deals with the last type of malocclusion, underbite. So far, we briefly introduced our reader to some of the causes and types of malocclusions. Next, we will refer to a more detailed description of an underbite, emphasizing its causes, associated problems, and clinical treatment.

What Is an Underbite?

An underbite is a dental condition where the lower jaw is mispositioned to the front of the mouth. An underbite can be mild and unnoticeable but still requires orthodontic treatment. However, a severe underbite can be quite evident.

A severe underbite alters the structure of the face making it look disproportionate. The mandible (lower jaw) exceeds the natural boundary set by the maxilla (upper jaw), pushing the lower lips, jaw, and jowl forward.

Not all underbites are the same. In addition, there are different levels of underbites. In a mild case, you might be unable to detect it. In severe cases, the jaw protrudes outward so far that it can be noticeable to others even with the mouth closed.

A severe underbite produces an unnatural and unaesthetic appearance. In medical terms, a severe underbite proceeds from a class of “Orofacial myofunctional disorders (OMDs) that are patterns involving oral and orofacial musculature that interfere with normal growth, development, or function of orofacial structures.”

The American Speech-Language-Hearing Association also includes that “OMDs can be found in children, adolescents, and adults, and can co-occur with a variety of speech and swallowing disorders. OMD may reflect the interplay of learned behaviors, physical/structural variables, genetic and environmental factors that cause an underbite.”

Is My Underbite Hereditary?

Dr. Nima Hajibaik specialized in orthodontics and is also part of the American Association of Orthodontics [AAO], who describes that “Most underbites are, in fact, hereditary.”

Ethnicity plays an essential role in genetics and the development of an underbite. For example, some Asian originals present lower percentages of normal occlusion with a higher propensity for underbite (mandibular prognathism).

The consanguineous marriages in the Habsburg dynasty that occurred in medieval times in Europe had been considered a cause for genetic mandibular prognathism.

Today we can find celebrities and royalty with an underbite. For instance, the Duchess of Cambridge, Kate Middleton, wife of Prince William. The Duchess has a slightly visible underbite. However, we can’t deny her beauty makes us forget about it.

Environmental Factors for an Underbite

Genes inheritance is a cause of underbite that escapes a patient’s control. However, in some cases, environmental aspects lead patients, especially children, to develop a protruded jaw, including:

Tongue Thrusting

Thrusting is a habit characterized by exerting constant pressure with the tongue against the lower teeth.

Mouth Breathing

Mouth breathing pushes the jaw forward while the jaw is developing.

Poor Lip and Mouth Posture

This habit occurs when the tongue is placed low, and the teeth and lips are forced apart at rest.

Correcting these types of habits requires parental observance. First, parents must notice any change that might lead to an underbite, so an orthodontist diagnoses it before starting an early intervention process.

Orthodontic early intervention enhances the chances of avoiding invasive treatment that might include a surgical procedure. Dr. Nima Hajibaik recommends parents bring their kids for an orthodontic consultation at seven while the child’s jaw is still forming, enhancing the possibility of reshaping it.

Do Babies Outgrow Underbites?

Yes, toddlers might show signs of underbite development. However, in some cases, these patterns are common. Therefore, the first piece of advice is not to be alarmed and to discuss the situation with a dental specialist.

In addition, or even without considering any physical appearance that could call your attention, you should be aware if your toddler presents difficulty chewing, have speech problems, have sleep apnea (snores), and starts developing tooth decay.

What Options Do I Have to Fix My Underbite Once and for All?

As we have previously mentioned, correcting an underbite is less dramatic if treated at an early age. However, teenagers and adults can benefit from orthodontic treatment.

Notwithstanding, depending on the opportunity of identification and severity of the underbite, treatment might require apparatus and sometimes surgery.

Please, don’t leave an underbite untreated, as it can affect the patient’s orofacial structures and function.

Here we include some of the procedures used to correct an underbite:


Braces are the most common mechanism used to correct an underbite. A mild underbite might require the use of braces. However, there might be severe cases where braces are the final step of a more complex treatment involving an Upper Jaw Expander and a Reverse Pull Headgear.

Upper Jaw Expander

An expander is a device that widens the jaw. The mechanics of an expander includes placing the device in the upper portion of the mouth (roof). Then, with the help of a key, the patient turns the expander to reach a position where both jaws’ widths match ultimately.

The second stage of the treatment requires the patient to use a reverse pull headgear (face mask). First, an orthodontist attaches the expander and the headgear with rubber bands. Then, the mechanism exerts a strain pulling the upper jaw (maxillary) backward.


Severe underbite cases require patients to undergo surgery to re-accommodate the jaw into the desired position. Unfortunately, once the jaw completes its formation process, the number of treatments available to correct underbite decreases, and sometimes surgery is the only option.

Furthermore, even after successful surgery, patients must use braces to realign teeth and improve the bite. Consequently, early identification and treatment ensure a less traumatic treatment option and highly desirable results.

When Can Children Start Their Treatment?

A general recommendation is to observe any developmental abnormality in your toddler relating to speech problems, masticatory difficulties, or noticing your little kid snoring. This might help have an awareness of a potential cause of an underbite.

We recommend parents visit Dr. Nima Hajibaik for a checkup while your kid is still a toddler, and a confirming visit by the age of seven, so your kid can start early intervention after a comprehensive diagnosis of an underbite. Set your next appointment with us.