What is an Overbite?


Class II malocclusions (more commonly referred to as an overbite or an overjet) is the most common problem presented to an orthodontist. It occurs when the upper jaw excessively overlaps the lower jaw, or the upper teeth are inclined forward at the front of the mouth. Approximately 30 -40 percent of our patients at Chatswood Orthodontics are treated for this condition.

There are two main causes of an excessive overjet, skeletal and dental. A skeletal Class II is related to a discrepancy in the jaw development and is commonly associated with a protruding or narrow upper jaw, underdevelopment of the lower jaw, or a combination of both. A skeletal Class II bite can be detected as early as the primary (baby) dentition and do not tend to self-correct with age. A dental overbite occurs when there are problems with the way the teeth come through, like overcrowding, or when teeth are put under pressure, like with thumb sucking or prolonged use of the dummy.

There are a few different factors that might contribute to this dental problem. Some of the common reasons include genetics, childhood habits such as thumb sucking, tongue thrusting, dummy use beyond age 3, or the prolonged use of a bottle, the loss of teeth, impacted teeth, or congenitally missing teeth.

Untreated, an overbite can cause speech problems, developmental issues related to airways such as poor sleeping and breathing habits, wearing of the teeth and poor dental and facial aesthetics.

Treatment for a Class II malocclusion in adolescents, depends on their growth status and is usually planned with the underlying cause in mind. When treating an overbite in growing children we prefer to use growth modification techniques to help develop the upper and lower jaw together to achieve facial and dental harmony, as well as good function and breathing. This is usually done with a functional appliance and a jaw expander which can be used in conjunction with braces, minimising the need for tooth extraction.

In adults, correction can be achieved with braces in milder case, or in more severe cases braces together with jaw surgery to improve the dental and facial aesthetics. In some cases, extractions may be required however, with the recent introduction of TADs (http://www.chatswoodorthodontics.com.au/tads/) the need for extractions and surgery may be reduced.

Stay tuned for Part 2 where we will discuss sleep disorders and airway obstruction in children.