An overbite describes the vertical overlap of the upper front teeth over the lower front teeth. While many believe an overbite is always a problem, a normal overbite is a healthy and functional part of a bite. An excessive overbite, however, can lead to various oral health issues.
Understanding Overbites
A normal overbite involves the upper front teeth vertically overlapping the lower front teeth by about 2 to 4 millimeters, covering approximately 20-40% of the lower teeth when the jaw is closed. This natural overlap aids in efficient chewing, protects soft tissues like gums and lips from damage, and contributes to facial aesthetics and speech clarity.
An “excessive” or “deep” overbite occurs when the upper teeth significantly cover the lower teeth, often by more than 4 millimeters or 30-40%. In severe cases, the upper teeth may completely obscure the lower teeth, or the lower teeth might even bite into the gum tissue behind the upper front teeth. Deep overbites affect a notable portion of the population, with some studies indicating that severe deep bites (5mm or more) are found in nearly 20% of children and 13% of adults.
Overbites can stem from dental issues, primarily with tooth position, or skeletal issues, indicating a discrepancy in jaw size or position. A skeletal overbite might occur if the lower jaw is smaller or positioned further back relative to the upper jaw. Dental overbites often involve misaligned teeth that push the lower jaw backward, even if jaw structures are properly aligned.
When an Overbite Needs Attention
An excessive overbite can lead to various problems beyond cosmetic concerns, impacting oral health and function. It can cause uneven or excessive wear on the teeth. Constant, abnormal contact between upper and lower teeth can prematurely wear down lower front teeth, potentially exposing sensitive layers and increasing the risk of cavities, chipping, or cracking.
Damage to the gums and roof of the mouth is also a concern. In deep overbites, lower front teeth may bite into the gum tissue behind the upper front teeth or the palate, leading to pain, irritation, gum recession, or sores. This continuous irritation can also increase the risk of periodontal issues.
Excessive overbites can also contribute to jaw pain and temporomandibular joint (TMJ) issues. Misalignment forces jaw muscles to work harder, leading to discomfort, chronic headaches, clicking or popping sounds in the jaw, and pain in the neck and shoulders. Difficulty chewing certain foods and speech impediments may also arise due to an improper bite. Protruding upper teeth also face a higher risk of injury.
Correcting an Overbite
Correcting an excessive overbite often involves orthodontic treatment, with the specific approach depending on the overbite’s severity, its underlying cause, and the individual’s age. Braces, either traditional metal or clear aligners, are a primary method for repositioning teeth. Braces utilize brackets and wires that are gradually tightened to apply pressure, moving teeth into their correct alignment. Clear aligners offer a less visible option, consisting of a series of removable trays that progressively shift teeth.
For younger patients whose jaws are still developing, palatal expanders may be used to widen a narrow upper jaw. These devices apply gentle pressure to encourage proper jaw growth, creating more space for teeth. Growth modification devices like headgear can also help correct skeletal overbites by guiding jaw development.
In more severe cases of skeletal overbite, particularly in adults where jaw growth is complete, orthognathic surgery (jaw surgery) may be necessary. This surgical procedure repositions the jaw bones to correct the structural discrepancy, often performed in conjunction with orthodontic treatment.
After overbite correction, retainers are typically used to maintain the new tooth and jaw positions, preventing relapse. Benefits include improved oral health, better chewing function, enhanced speech, and a more balanced facial appearance.