A deep bite, also known as an excessive overbite, is a common dental misalignment where the upper front teeth significantly overlap the lower front teeth when the jaw is closed. While some vertical overlap is normal, a deep bite occurs when the upper teeth cover more than one-third of the lower teeth. This malocclusion means the teeth and jaws do not align correctly. An untreated deep bite can cause serious issues, including excessive wear on the biting surfaces of the front teeth. In severe cases, the lower front teeth can bite into the gum tissue behind the upper incisors, causing irritation, damage to the palate, and periodontal problems. The misalignment can also strain chewing muscles and joints, potentially contributing to jaw pain or temporomandibular joint (TMJ) disorders.
Diagnosis and Optimal Treatment Timing
A thorough diagnostic assessment determines the underlying cause and severity of the vertical overlap. An orthodontist performs a clinical examination and uses specialized X-rays, such as panoramic and cephalometric radiographs, to measure the relationship between the teeth and the jaw bones. Cephalometric analysis helps distinguish a deep bite that is primarily dentoalveolar (related to tooth position) from one that is skeletal (related to jaw structure imbalance).
Treatment timing is crucial, especially in younger, growing patients. Early intervention, often called Phase 1 treatment, typically starts around ages seven to ten, utilizing remaining growth potential to guide jaw development. Appliances used during this phase can modify jaw growth patterns, making skeletal corrections easier to achieve later.
Treating adolescents and adults, where skeletal growth is complete, requires a different approach, relying primarily on mechanical tooth movement or surgical correction for severe issues. For non-growing patients, the focus shifts to relocating the teeth within the existing jaw structure through methods like intrusion, which pushes teeth back into the bone.
Standard Orthodontic Correction Methods
The most common way to fix a deep bite involves non-surgical orthodontic mechanics that reposition the teeth to reduce vertical overlap. One early method uses a removable or fixed bite plate or bite turbo. These are small acrylic or composite ramps placed on the back of the upper front teeth or on the chewing surfaces of the back teeth. These appliances temporarily prevent the front teeth from fully contacting, separating the bite and allowing the back teeth to naturally erupt while the anterior teeth are pushed down.
Once fixed appliances like braces are used, a primary mechanism for deep bite correction is the simultaneous intrusion of the front teeth and extrusion of the back teeth. Orthodontists achieve this using specific archwire shapes, most notably the reverse curve of Spee. This specialized wire is curved upward in the front and downward in the back, delivering light forces to push the incisors into the bone while pulling the molars and premolars out of the bone. This combination effectively opens the bite and increases the overall vertical dimension.
Clear aligner therapy also incorporates specific features to manage the vertical dimension. Many aligner systems utilize custom-designed bite ramps or bite turbos built directly into the plastic trays behind the upper front teeth. When the patient bites down, the lower teeth contact these ramps, directing force to push the lower incisors back into the bone, achieving the necessary intrusion. This mechanism provides an alternative to traditional wires for achieving vertical tooth movement.
Surgical and Advanced Interventions
For severe deep bites primarily caused by a significant skeletal imbalance—where the jaw bones are disproportionate—standard orthodontic tooth movement alone may not be sufficient. In these complex situations, especially in non-growing adults, orthognathic surgery, or corrective jaw surgery, is required to physically reposition the jaw segments. This surgical approach is often necessary when a short or underdeveloped lower jaw causes the excessive vertical overlap.
The surgery involves carefully cutting and repositioning the upper jaw, the lower jaw, or both, to achieve a harmonious and functional relationship. Procedures might include mandibular advancement to bring a retruded lower jaw forward, which simultaneously opens the deep bite. This surgery is always performed alongside precise pre- and post-surgical orthodontics to ensure the teeth align perfectly once the jaws are repositioned.
Another advanced intervention that can sometimes prevent the need for surgery in borderline skeletal cases is the use of Temporary Anchorage Devices (TADs). These are small, biocompatible mini-screws placed temporarily into the bone, acting as a fixed, immovable anchor point. TADs allow the orthodontist to apply maximum force to intrude the anterior teeth directly and efficiently. This stable anchor enables pure tooth movement without unwanted reciprocal forces that could cause the back teeth to shift or tilt.
Retention and Maintaining Results
The final phase of deep bite correction, known as retention, is crucial because the teeth and surrounding tissues have a strong biological tendency to return to their original position. This relapse tendency stems from the memory of the periodontal ligaments and the forces exerted by the facial and tongue muscles. Long-term retention is necessary to stabilize the corrected vertical dimension.
Specific retainers are designed to actively prevent the bite from deepening again. A common appliance is a removable retainer, such as a Hawley or clear Essix-type, that incorporates an anterior bite plate or ramp. The lower incisors contact this plate, which helps maintain the new vertical spacing established during treatment and prevents the lower teeth from sliding back up behind the upper ones.
A bonded fixed lingual retainer—a thin wire cemented to the tongue-side of the lower front teeth—is also used to stabilize vulnerable teeth against relapse. For optimal stability, especially after significant intrusion, retainers should be worn consistently, often nightly for an indefinite period.