Negative Overjet Treatment

Negative overjet Treatment

Negative overjet, also known as reverse overjet, occurs when the upper teeth are positioned behind the lower teeth when the jaws are closed. This condition is the opposite of a normal overbite, where the upper teeth slightly overlap the lower teeth. Negative overjet is often a sign of a skeletal or dental malocclusion and can cause functional and aesthetic concerns. Treatment typically involves addressing the underlying causes, which may include jaw discrepancies, teeth positioning, or habits like thumb-sucking or tongue thrusting.

Causes of Deep Bite

Genetics: A deep bite is often inherited and may be caused by jaw growth abnormalities or the way the teeth erupt. If parents have a deep bite, there is a higher likelihood that their children will develop it.
Malocclusion (Improper Bite): A misalignment of the upper and lower teeth, often due to the way the teeth and jaws develop. This can lead to an abnormal vertical overlap.
Thumb Sucking: Prolonged thumb sucking in children can affect the development of the teeth and jaws, leading to a deep bite.
Tongue Thrusting: If a person thrusts their tongue forward against the teeth when swallowing, it can push the teeth into improper positions, contributing to a deep bite.
Jaw Abnormalities: Conditions like overgrowth of the upper jaw (maxilla) or underdevelopment of the lower jaw (mandible) can cause a deep bite. These conditions may be due to genetic factors or certain health issues.
Teeth Wear or Loss: Wear and tear of teeth over time, or loss of teeth, can alter the bite and potentially lead to a deep bite, especially if the teeth have been worn down unevenly.

Treatment Options for Negative Overjet

Treatment for a deep bite varies depending on the severity and the underlying cause. The goal is to restore normal function and prevent further damage to the teeth and gums. Common treatment methods include:

Orthodontic Treatment:

Braces: Traditional braces are often the primary treatment for correcting a negative overjet, particularly in cases where the teeth are misaligned, but the jaw structure is normal. Braces can help reposition the teeth to correct the bite.
Clear Aligners:For some cases, clear aligners (like Invisalign) might be used as an alternative to traditional braces. However, these are typically effective in milder cases.

Functional Appliances:

Headgear:In growing patients, headgear may be used to control the position of the upper jaw and prevent further misalignment. This is often used in conjunction with braces to correct skeletal discrepancies.
Bionator or Twin Block:These are types of functional appliances used to encourage proper jaw growth and alignment, particularly in younger patients. These devices are designed to help move the lower jaw back and the upper jaw forward.

Surgical Intervention:

Orthognathic Surgery:In cases of severe skeletal discrepancies where the jaw positions are significantly out of alignment, surgery may be required. This is typically done in adults after growth has stopped and is often combined with orthodontic treatment to achieve a functional and aesthetic outcome.
Jaw Advancement or Reduction:Depending on the cause of the negative overjet (e.g., a retrusive upper jaw or an excessively prominent lower jaw), the surgeon may reposition the upper or lower jaw.

Restorative and Prosthetic Treatment:

Crowns or Veneers: In some cases, dental crowns or veneers may be used to correct minor alignment issues or compensate for small tooth misalignments. However, these are typically not used as a primary treatment for correcting negative overjet.

Growth Modification (in children):

For children and adolescents who are still growing, there are options to modify jaw growth. Appliances like the Herbst appliance or the facemask (reverse pull headgear) are designed to encourage forward growth of the upper jaw, which may help correct the negative overjet.

Myofunctional Therapy:

In cases where habits like tongue thrusting or thumb-sucking are contributing to the negative overjet, myofunctional therapy can help retrain the muscles of the mouth to function correctly. This type of therapy may be used in conjunction with other orthodontic treatments.

Factors to Consider in Treatment Planning

Age: Treatment outcomes may vary depending on the patient's age. Younger patients with growing jaws may have better outcomes with functional appliances or growth modification. In contrast, adult patients may need more invasive treatments like surgery.
Severity of the Overjet: A mild negative overjet may be treated effectively with orthodontic appliances alone, while a severe overjet may require surgical intervention.
Underlying Causes: The cause of the negative overjet, such as skeletal issues (jaw position) or dental issues (tooth positioning), will affect the type of treatment recommended.
Patient Compliance: For treatments like headgear or functional appliances, patient cooperation is crucial. Non-compliance can lead to delayed or ineffective results.

Prognosis and Long-Term Care

The prognosis for treating negative overjet is generally good if the condition is addressed early and the appropriate treatment is applied. Regular follow-ups with the orthodontist are essential to ensure that the teeth remain in their corrected positions after treatment. After active treatment, some patients may require retainers to maintain the new alignment of the teeth and prevent relapse.

In some cases, after achieving the desired alignment, the patient may also undergo periodic monitoring to ensure the jaws remain aligned, especially if they have had surgical intervention.

Potential Risks of Untreated Negative Overjet

Functional Issues: A reverse bite can make it difficult to chew or bite properly, potentially leading to discomfort and difficulty eating.
Speech Issues: Misalignment of the teeth can also affect speech, causing lisping or other speech problems.
Wear on Teeth: A negative overjet can lead to abnormal wear patterns on the teeth, particularly if the lower teeth are constantly in contact with the upper teeth in an unusual way.
Aesthetic Concerns: A negative overjet may also affect facial appearance, leading to a "bulldog" profile, with a prominent lower jaw and a receded upper jaw.