Braces are an effective method for correcting an overbite, one of the most common types of malocclusion, or improper bite. An overbite is a complex issue involving the position of the teeth, the alignment of the jaws, or both. Correcting this misalignment is a standard orthodontic procedure, utilizing the consistent forces of braces to guide teeth into a healthy relationship. Successful treatment improves appearance and mitigates potential problems like excessive tooth wear and jaw discomfort. The specific approach depends heavily on the underlying cause and the degree of vertical overlap.
Defining the Overbite and Its Severity
An overbite, often called a deep bite, is a vertical issue where the upper front teeth excessively overlap the lower front teeth. While some vertical overlap is normal, it becomes a malocclusion when the overlap exceeds about one to two millimeters, or roughly one-third of the lower incisor crown height. Overlap exceeding three millimeters is considered excessive and usually requires orthodontic intervention. Overbite is distinct from overjet, which describes the horizontal protrusion of the upper front teeth.
Overbites are classified by origin: a dental overbite involves incorrect tooth positioning, while a skeletal overbite results from a mismatch in the size or position of the upper and lower jaws. A severe deep bite can cause the lower teeth to bite into the palate tissue or lead to significant wear on the biting surfaces. Orthodontists measure the severity to determine the appropriate treatment plan.
The Mechanism of Overbite Correction with Braces
Traditional fixed braces are effective for overbite correction because they allow for precise, controlled vertical movement of individual teeth. The main objective is to reduce the vertical overlap using two primary movements: intrusion and extrusion. Intrusion is the vertical movement of a tooth into the jawbone, typically applied to the front teeth to push the incisors deeper into the bone. This movement reduces the overlap between the upper and lower front teeth.
Extrusion, the opposite movement, is the vertical shifting of a tooth out of the jawbone, usually applied to the back teeth. By slightly extruding the molars and premolars, the back of the bite is opened, which rotates the lower jaw and helps reduce the deep bite. Orthodontic archwires are shaped to create a pronounced curve, known as a reverse curve of Spee, which applies these forces. Brackets are strategically placed to facilitate the necessary forces for intrusion of the front teeth and extrusion of the back teeth, leveling the plane where the teeth meet.
The sustained force provided by the archwire against the brackets drives the biological process of tooth movement. In some cases, specialized attachments like bite turbos or bite plates may be bonded to the teeth. These temporarily prevent the front teeth from fully contacting, which prevents interference and encourages the back teeth to erupt slightly, further opening the bite.
Specialized Appliances and Surgical Interventions
For cases where the overbite has a skeletal origin, treatment often requires methods beyond standard fixed braces. In growing patients, functional appliances like the Herbst or MARA devices modify jaw growth by posturing the lower jaw forward. These appliances work best during active growth spurts, helping the lower jaw catch up to the size of the upper jaw and improving the skeletal relationship.
Clear aligners, such as Invisalign, can also correct mild to moderate dental overbites. These aligners utilize attachments to grip the aligner and enable complex movements, including intrusion and extrusion. However, severe skeletal overbites or those requiring significant jaw movement often necessitate traditional braces or a combination of methods. For adults with severe skeletal discrepancies that cannot be corrected by tooth movement alone, orthognathic surgery is necessary to physically reposition the upper or lower jaw. This surgery is typically preceded and followed by comprehensive orthodontics to ensure the teeth align perfectly with the newly positioned jaws.
Treatment Duration and Maintaining Results
The time required to correct an overbite with braces varies based on the severity of the malocclusion and the patient’s age. Mild cases may be completed in six to twelve months, but moderate to severe overbites often require twelve to thirty-six months of active treatment. Consistent patient compliance, especially the diligent wearing of prescribed rubber bands or removable appliances, significantly affects the timeline. Regular adjustments, typically every four to eight weeks, are necessary to ensure the teeth move along the planned path.
Once the active orthodontic phase is complete, the retention phase begins, which is crucial for long-term stability. Overbite corrections have a high tendency for relapse, meaning the teeth may shift back toward their original position. Retainers, which can be fixed (a wire bonded behind the front teeth) or removable, must be worn as directed to prevent this. The protocol involves wearing retainers full-time initially, followed by a transition to indefinite nighttime wear to maintain the corrected bite.