Our upper teeth are designed to nestle into the grooves between the lower teeth, resulting in a proper bite. When the teeth are misaligned so that the teeth don’t quite fit, this is called malocclusion. “Mal” means “bad,” and “occlusion” is another word for “bite.” In the late 19th century, Edward Angle differentiated types of “bad bites” into classes of malocclusion, including a Class 2 malocclusion.

What is a Class 2 malocclusion?

Class 2 malocclusion is also referred to as retrognathism or overbite.

This malocclusion occurs when the upper jaw protrudes over the lower jaw. Although some overlap is normal, this type of malocclusion sees the lower teeth completely hidden by the upper teeth.

What causes a malocclusion?

Very few people are born with a perfect bite. Most of us have some variation that leans towards one of the malocclusion classes. There are some factors that can cause or worsen malocclusion, including:

  • Excessive pacifier use or thumb sucking
  • Birth defects
  • Genetic disorders
  • Irregular growth patterns
  • Underlying bone structure

Behavioral causes

Extended use of a pacifier or thumb sucking can cause or increase the chances of malocclusion. The thumb or pacifier begins to act as a guide for growing teeth, forcing them forward and out.

Once this pattern is established in baby teeth, adult teeth may follow it. Certainly, if thumb sucking continues into early adolescence it can lead to malocclusion.

Birth defects or genetic disorders

Cleft palate, cleft lip, and sometimes lip and tongue tie can cause malocclusion.

Irregular growth patterns

Although our bone structure is essentially the same in theory, in practice, there are all kinds of possibilities when it comes to how baby teeth and adult teeth emerge.

Baby teeth may stubbornly hold on, forcing adult teeth to erupt differently. Adult teeth may come in at an angle. Environmental factors (e.g., pacifier use and thumb sucking) can make these irregular patterns worse.

Underlying bone structure

In some cases, the upper and lower jaws are out of proportion.

In a “perfect” bite, the upper teeth fit just over the lower teeth (with the lower teeth still visible). A person with a malocclusion may see a smaller upper or lower jaw that results in malocclusion.

What are the different malocclusion types?

In addition to a Class 2 malocclusion, there is also Class 1 and Class 3 malocclusion. A Class 1 malocclusion is the most common variation in bite. While the bite itself is considered “normal,” the teeth do not necessarily fit together due to overcrowding.

A Class 3 malocclusion is the opposite of a Class 2. The lower jaw pushes forward past the upper jaw, sometimes so much so that the upper teeth rest inside the lower teeth. This is referred to as prognathism or an underbite.

How can I tell if I have a Class 2 malocclusion?

While a Class 2 malocclusion can be diagnosed visually in some cases, it often brings with it other symptoms, such as:

  • Jaw pain
  • Uneven tooth wear
  • Speech impediment or difficulty speaking
  • Difficulty eating
  • Changes in facial structure

Jaw pain is just one of the symptoms that can affect everyday life, but the others may have long-term consequences.

Uneven tooth wear

Uneven tooth wear is a problem that gets worse over time.

Enamel is deeply worn in some places, leading to other dental issues such as cavity and cracks that can lead to tooth abscess.

Speech impediment or difficulty speaking

Kids developing speech and language can struggle with both if their Class 2 malocclusion remains untreated.

The teeth interfere with the tongue and affect how words are physically formed in the mouth. This can be challenging to remedy as children grow up.

Difficulty eating

Because the bite is uneven, children may have difficulty getting adequate nutrition as they grow.

If parents opt for mostly soft foods, this lack of hard food can make teeth weaker as the child grows, which affects future dental health.

Changes in facial structure

A Class 2 malocclusion can change the facial features and overall structure of the face, a change which may require surgery to repair if left untreated.