Overbites & Underbites Explained
What Is an Overbite?
An overbite occurs when the upper front teeth overlap the lower front teeth vertically. A small amount of overlap is normal and actually helps the front teeth work together when biting and chewing.
An excessive overbite, sometimes called a deep bite, occurs when the upper teeth overlap the lower teeth more than expected. In more pronounced cases, the lower front teeth may come into contact with the roof of the mouth or the gum tissue behind the upper teeth.
What Is an Underbite?
An underbite occurs when the lower front teeth sit in front of the upper front teeth when the mouth is closed. Underbites can result from the lower jaw developing farther forward than expected, the upper jaw being positioned farther back, or the teeth compensating for an underlying difference in jaw position. Like overbites, underbites can range from mild to pronounced.
What Causes Overbites and Underbites?
Overbites and underbites can develop for similar reasons. The key difference is how those factors affect the relationship between the upper and lower teeth and jaws.
Common contributing factors include:
- Jaw growth: Differences in the size, position, or growth of the upper and lower jaws can affect how the bite develops.
- Tooth position: Teeth that erupt too far forward, backward, or at an unusual angle can contribute to an uneven bite.
- Genetics: The size and shape of the jaws, facial structure, and patterns of tooth development are influenced by inherited traits.
- Crowding or spacing: Irregular tooth positions can alter how the upper and lower teeth come together.
- Childhood habits: Prolonged thumb or finger sucking and certain other oral habits can affect dental and jaw development in some children.
How Are Overbites and Underbites Treated?
Treatment depends on what is causing the bite problem, how pronounced it is, and whether the jaws are still growing. The same type of bite can require different treatment approaches in different people.
Tooth-related bite problems
When an overbite or underbite is primarily caused by the position of the teeth, braces or clear aligners may be used to move the teeth into better positions and improve the way the upper and lower teeth meet.
Other orthodontic appliances may sometimes be used alongside braces or aligners. The specific approach depends on the type of movement required and the patient’s stage of dental development.
Bite problems related to jaw growth
When the position or growth of the jaws contributes significantly to the bite, treatment may be more involved.
For children and teens who are still growing, orthodontic appliances may sometimes be used to influence the developing relationship between the upper and lower jaws. Timing can be particularly important with underbites because continued lower-jaw growth may affect the bite as a child matures.
In adults, jaw growth is complete, so orthodontic treatment cannot change the size or position of the jaws. If there is a significant misalignment, jaw surgery may be considered alongside orthodontic treatment.
Does Every Overbite or Underbite Need Treatment?
No. A bite that looks different from average does not automatically mean that treatment is necessary.
Treatment may be considered when overbite/underbite affects any of the following activities:
- Chewing or other oral function
- The ability to clean the teeth effectively
- The health of the gums or surrounding tissues
- Tooth wear or damage
- The position or eruption of other teeth
- Jaw function or comfort
- Long-term dental health
Some mild bite problems may only need monitoring, especially in children. More complex cases may require a combination of monitoring and actual treatment.
The Importance of Timing
The best time to treat an overbite or underbite varies from person to person. Some tooth-position problems can be addressed effectively at different stages of life, while problems involving jaw growth may be more time-sensitive.
For children and teens, an orthodontic evaluation can help determine whether treatment should begin during growth, be delayed until more permanent teeth have erupted, or simply be monitored.
For adults, treatment planning takes into account the fact that jaw growth is complete. Tooth movement remains possible, but orthodontics cannot change the size or position of the adult jaw in the same way that growth-related treatment can influence a developing bite.
Understanding the Treatment Options
Overbites and underbites can have very different causes, so effective treatment starts with understanding the individual bite. At Seager Orthodontics, our orthodontists assess tooth position, jaw development, and overall bite to determine the best path forward for you! Schedule an initial consultation to get started.