Overjet, often confused with an overbite, is a common orthodontic condition defined by the horizontal protrusion of the upper front teeth past the lower teeth. A normal bite typically features a slight two-millimeter horizontal overlap of the upper incisors over the lower ones. When this horizontal distance is significantly greater, it is classified as an overjet. This misalignment, sometimes colloquially referred to as “buck teeth,” is a form of malocclusion that can result from genetic factors influencing jaw size or from childhood habits like prolonged thumb sucking.
Why Timing Matters for Treatment Success
The most effective strategy for correcting an overjet depends heavily on a patient’s age and remaining skeletal growth potential. Early intervention, known as Phase I or interceptive treatment, is typically recommended for children around age seven. This timing is beneficial because the jawbones are still actively developing and are more pliable, allowing for guidance of future growth.
Interceptive treatment often utilizes growth modification appliances that encourage the lower jaw to grow forward, correcting the skeletal discrepancy. If treatment is delayed until all permanent teeth have erupted and growth has slowed—usually in the early teenage years or adulthood—the focus must shift from skeletal modification to tooth movement. At this later stage, the underlying jaw structure is mostly set, making correction of a severe overjet more complicated and sometimes less stable without surgery.
Non-Surgical Approaches to Overjet Correction
For overjet cases resulting primarily from misaligned teeth or mild jaw discrepancies, non-surgical methods remain the standard approach. Traditional braces apply continuous, gentle pressure through brackets and wires to reposition teeth within the jawbone. This movement effectively retracts the protruding upper incisors and brings the lower teeth forward to reduce the horizontal gap.
Orthodontists frequently use specialized attachments, like elastic bands or fixed springs, with braces to apply directional force between the upper and lower teeth. These elastics are worn between the two arches, actively pulling the upper teeth backward and the lower teeth forward to improve the bite relationship. Clear aligners are also a viable option for many mild to moderate overjet corrections, using a series of custom-made trays to gradually shift the teeth.
In growing patients, specialized appliances are often employed to harness the body’s natural growth spurt. Fixed functional appliances, such as the Herbst appliance, or removable appliances like the Twin Block, physically hold the lower jaw in a more forward position. By maintaining this forward posture, these devices aim to stimulate growth in the lower jaw, effectively closing the overjet at a skeletal level while the bones are still maturing. This early skeletal correction can reduce the complexity and duration of later comprehensive orthodontic treatment.
Addressing Severe Overjet with Surgery
When overjet is the result of a skeletal mismatch—such as a lower jaw that is smaller or set back compared to the upper jaw—orthodontic treatment alone may be insufficient. These severe cases require a combined approach known as orthognathic surgery, or corrective jaw surgery, to reposition the facial bones themselves. The goal is to achieve a stable and functional bite that is not possible through tooth movement alone.
The process is structured into three phases, beginning with pre-surgical orthodontics, which typically lasts from twelve to eighteen months. During this period, the orthodontist uses braces or aligners to align the teeth within their respective jaws, often making the bite temporarily appear worse. This is a deliberate step, as it ensures the teeth will fit together precisely once the jaws are surgically moved.
The oral and maxillofacial surgeon then performs the orthognathic surgery, usually in a hospital setting, to physically advance the lower jaw or set back the upper jaw. The surgery involves making precise cuts, called osteotomies, in the jawbone and securing the repositioned segments with small plates and screws. Following the healing period, a final phase of post-surgical orthodontics is necessary to fine-tune the bite and achieve the final tooth alignment.
Maintaining Results After Active Treatment
Following the completion of active overjet correction, the retention phase begins for long-term stability. Teeth have a biological memory and a natural tendency to shift back toward their original, misaligned positions, a phenomenon known as relapse. This is particularly true in cases where the initial malocclusion was severe.
Retainers are designed to prevent this relapse by holding the teeth in their newly corrected alignment until the surrounding bone and gum tissues stabilize. There are two primary types of retainers: fixed and removable. Fixed retainers are thin, custom-fitted wires bonded to the back surface of the front teeth, providing continuous, passive retention.
Removable retainers, such as vacuum-formed clear trays or Hawley appliances, are worn full-time initially and then typically transition to nightly wear indefinitely. Lifelong use of a retainer, at least part-time, is widely accepted as the standard protocol to maintain the corrected overjet and preserve the treatment result against the forces of natural aging and subtle tissue changes.