An overbite describes the vertical overlap of the upper front teeth over the lower front teeth. A slight overlap is a normal and healthy component of a person’s bite, and many individuals have a minor overlap without issues.
Understanding Overbite Measurement
Overbites are typically measured in millimeters (mm) or as a percentage of the lower teeth covered by the upper teeth. A normal overbite is 2 to 4 millimeters of vertical overlap. As a percentage, this means the upper teeth cover about 20% to 30% of the lower incisors. Some sources suggest a range of up to 40% can also be considered normal if there are no associated functional problems.
This slight overlap is considered ideal for proper chewing, speaking, and maintaining facial appearance. It ensures that the lower front teeth lightly touch the back of the top front teeth, providing stability and leverage. A healthy overbite also helps protect teeth from excessive wear and tear.
When an Overbite Becomes a Concern
An overbite becomes a concern when the vertical overlap is excessive, often referred to as a “deep bite.” This happens when the upper front teeth cover more than 3 millimeters or exceed 30-40% of the lower teeth. In severe cases, the lower teeth might disappear behind the upper teeth or even bite into the gum tissue behind the upper front teeth.
Excessive overbites can lead to problems, including accelerated wear on the tooth enamel, gum irritation or damage, jaw pain, and temporomandibular joint (TMJ) disorders. Individuals might experience difficulty chewing, speech impediments, headaches, or even breathing issues.
Factors Contributing to Overbite Development
Overbite development stems from genetic and environmental factors. Genetics play a significant role, as inherited jaw structure and tooth size discrepancies can predispose an individual to an overbite. For instance, a smaller lower jaw compared to the upper jaw can lead to increased overlap.
Childhood habits also contribute to overbite development. Prolonged thumb-sucking, pacifier use past early childhood, and tongue thrusting can exert pressure on the developing teeth and jaw, influencing their alignment. Also, issues like missing or extra teeth, tooth grinding (bruxism), or even nail-biting can impact dental alignment over time.
When to Consult a Professional
Consult a dentist or orthodontist if an overbite causes discomfort or functional issues. Indicators for evaluation include jaw pain, difficulty chewing or speaking, or visible wear on the teeth. An orthodontist can accurately assess the severity of the overbite and determine if treatment is necessary.
Early intervention, particularly during childhood, can lead to more straightforward treatment outcomes. However, orthodontic solutions are available for adults as well. Only a dental professional can provide a personalized assessment and recommend the most appropriate course of action.