Braces can fix an overjet, as this condition is one of the most common and successfully treated issues in orthodontics. Overjet is a type of malocclusion, or “bad bite,” resulting from a misalignment between the upper and lower jaws or teeth. Advances in orthodontic technology allow for correction in patients of nearly any age, offering improvements in function and appearance. Treatment is highly individualized, depending on the underlying cause and the patient’s stage of growth, but it typically involves an orthodontic appliance to align the teeth and jaws.
Defining the Overjet Condition
Overjet is the horizontal overlap of the upper front teeth over the lower front teeth, often referred to as “buck teeth.” This condition is a horizontal misalignment where the upper incisors protrude too far forward when the back teeth are closed. A healthy bite typically involves a horizontal separation of only about 2 to 3 millimeters between the upper and lower front teeth. An overjet is diagnosed when this horizontal measurement exceeds that normal range.
Overjet is often confused with overbite, which refers to the vertical overlap of the teeth. Overjet is classified as a Class II malocclusion and can stem from two primary sources. A dental overjet means the teeth are misaligned despite a correctly positioned jaw structure, often due to habits like prolonged thumb-sucking. A more complex skeletal overjet involves a structural discrepancy, such as an upper jaw that is too far forward or a recessed lower jaw.
An excessive overjet can lead to several functional issues, including difficulty biting or chewing certain foods. Protruding upper teeth are also significantly more vulnerable to accidental trauma, such as chipping or fracture, especially during sports or falls. Furthermore, a severe overjet can sometimes make it difficult to completely close the lips without straining, which can lead to dry mouth and an increased risk of dental decay.
How Braces and Appliances Correct Overjet
The strategy for correcting an overjet is dictated by whether the cause is primarily dental or skeletal. For a dental overjet in which the jaw relationship is relatively balanced, correction is achieved through dentoalveolar movement, often called orthodontic camouflage. This process uses fixed braces, wires, and elastic bands to retract the upper front teeth backward and, in some cases, slightly protract the lower front teeth forward. This movement effectively closes the horizontal gap by repositioning the teeth within the jawbones.
For more severe cases or those with a skeletal discrepancy in a growing child, specialized fixed functional appliances are used alongside or before braces. Devices like the Herbst or Mandibular Anterior Repositioning Appliance (MARA) work by holding the lower jaw in a forward position. The Herbst appliance uses a telescopic rod and tube mechanism connecting the upper and lower molars, while the MARA uses a system of elbow-and-arm guides to mechanically posture the mandible forward. This constant forward pressure encourages the lower jaw to develop in a more advanced position while simultaneously restricting the forward growth of the upper jaw.
These functional appliances are non-removable, which eliminates the compliance issues often associated with removable headgear. Once the skeletal relationship is improved, traditional braces or aligners are then used to fine-tune the final alignment of the individual teeth. For adults with a severe skeletal overjet, the underlying jaw discrepancy cannot be corrected by growth modification, requiring a combined approach of orthodontics and orthognathic (jaw) surgery.
The orthodontic phase before surgery involves “decompensation,” where the teeth are moved into a position that allows the surgeon to perform the necessary jaw correction. This often results in a temporary increase in the overjet before the surgical procedure. Surgery typically involves a Bilateral Sagittal Split Osteotomy (BSSO) to advance the lower jaw and may also include a Le Fort I osteotomy to reposition the upper jaw. This combined treatment corrects both the dental alignment and the skeletal imbalance.
Factors Affecting Treatment Success and Duration
The success and overall duration of overjet treatment are influenced by several interconnected factors, with patient age being one of the most significant. Early intervention for skeletal issues is highly advantageous, as functional appliances like the Herbst or MARA are most effective when a child is still experiencing a growth spurt. Treating a skeletal discrepancy during this time allows the orthodontist to harness natural growth, which typically results in a shorter overall treatment time.
The severity of the overjet also plays a large role in determining the complexity and length of the treatment plan. Mild cases resulting from minor dental tipping may be corrected relatively quickly, sometimes in under two years. Conversely, severe skeletal discrepancies requiring a phased treatment with functional appliances or eventual orthognathic surgery can extend the treatment duration to three years or longer, especially when including the pre-surgical orthodontic phase.
Patient compliance is another factor that directly impacts the outcome, particularly in treatments that rely on removable components. While fixed functional appliances remove this variable, patients undergoing dentoalveolar correction often rely on wearing small elastics between the upper and lower jaws. Failure to wear these elastics consistently for the prescribed hours each day can stall tooth movement and add months to the total treatment time.
The retention phase is essential for long-term success and stability. After the braces are removed and the overjet is corrected, the surrounding bone and soft tissues need time to stabilize around the new tooth and jaw positions. Patients are required to wear retainers, which may include a combination of fixed lingual wires bonded behind the teeth and removable Hawley or clear overlay retainers. Consistent retainer wear prevents the teeth from gradually shifting back toward their original, misaligned position, securing the achieved correction.