Braces are a primary and highly effective method for correcting an overbite, one of the most common bite problems treated in orthodontics. An overbite occurs when the upper front teeth significantly overlap the lower front teeth when the mouth is closed. Orthodontic treatment systematically moves teeth and sometimes modifies jaw position to address the functional and aesthetic issues caused by this misalignment, also known as a Class II malocclusion.
Defining the Overbite
An overbite, or deep bite, is a form of malocclusion characterized by an excessive vertical overlap of the upper incisors over the lower incisors, typically exceeding 3 millimeters or 30% coverage. It is distinct from an overjet, which refers to the horizontal protrusion of the upper teeth beyond the lower teeth. This condition is often classified as a Class II malocclusion.
The causes of an overbite include hereditary factors that dictate jaw size and structure. Prolonged childhood habits like thumb-sucking, pacifier use, and abnormal jaw growth patterns can also contribute to its development. Discrepancies in the size of the upper and lower jaws, often where the lower jaw is underdeveloped or set back, are a frequent skeletal factor.
Correction is pursued not just for aesthetic reasons, but because an untreated overbite can lead to various functional and health issues. Excessive overlap can cause the lower teeth to bite into the gum tissue behind the upper teeth, leading to sores and tissue damage. Over time, an improper bite places uneven stress on the teeth, resulting in premature wear, chipping of the enamel, and potential temporomandibular joint (TMJ) disorders.
How Braces Reposition Teeth
Standard fixed braces utilize a system of brackets, archwires, and ligatures to apply continuous, gentle force that gradually shifts teeth into new positions. The brackets are bonded to the front of each tooth, acting as handles through which the archwire threads. This archwire is the active component, providing the necessary pressure to guide the teeth along a specific path of movement.
For overbite correction, the primary goal is often to level the dental arches and reduce the vertical overlap. This is achieved by either slightly intruding (pushing down) the upper front teeth or extruding (pulling up) the back teeth, or a combination of both movements.
In mild to moderate cases, braces alone can often accomplish the necessary tooth movements by carefully adjusting the archwire throughout treatment. Orthodontists may also use auxiliary components like bite pads or bite turbos, which are small composite ramps placed on the back of the upper front teeth or on the molars. These appliances temporarily prevent the back teeth from touching, allowing them to naturally drift into a more open position and protecting the lower brackets from being bitten off.
Specialized Appliances for Jaw Alignment
For more severe overbites caused by a skeletal discrepancy, specialized appliances are often required in addition to braces. These tools are particularly effective in growing patients, as they can modify and guide the development of the jawbones. Functional appliances, such as the Herbst or Mandibular Advancement Appliance (MARA), work by holding the lower jaw in a forward position.
The Forsus Fatigue Resistant Device serves a similar function, promoting mandibular growth and reducing the overbite. These fixed appliances are often worn for six to fifteen months, frequently before or concurrently with full braces. Orthodontic elastics, or rubber bands, play a crucial role in coordinating the final bite relationship between the upper and lower arches by applying continuous, light force. In severe skeletal cases where jaw growth is complete, orthognathic (jaw) surgery may be necessary in adulthood to reposition the jawbones.
Maintaining the New Bite
Once the overbite has been corrected and the braces are removed, retention begins. Teeth have a natural tendency to shift back toward their original misalignment, a process called orthodontic relapse. Retainers are custom-made appliances designed to stabilize the teeth and surrounding bone, preventing this undesirable return to the deep bite. The long-term success of overbite correction relies heavily on consistent retainer wear.
Retainers come in several forms, including removable Hawley retainers made of acrylic and wire, or clear plastic Essix retainers. Fixed retainers, which are thin wires bonded to the back surface of the front teeth, are also commonly used to provide permanent stabilization. The prescribed wear time typically begins with full-time use for several months, transitioning to nightly wear, often for an indefinite period to ensure the stability of the corrected bite.