Overjet: Symptoms, Types, Causes and Treatment

Overjet is more than just a dental term—it's a condition that can impact your health, confidence, and daily comfort. Whether you’re a concerned parent, an adult considering orthodontics, or simply curious about dental health, understanding overjet is the first step toward effective management. This comprehensive guide dives into the symptoms, types, causes, and modern treatments available for overjet, all grounded in current research.

Symptoms of Overjet

Overjet can manifest in various ways, some subtle and others more obvious. Recognizing these symptoms early can help prevent complications and guide you toward the right treatment.

Symptom	Description	Impact	Source(s)
Protrusion	Upper front teeth extend forward	Affects appearance, bite	1 3 5
Speech	Difficulty pronouncing certain words	Communication issues	3 5
Chewing	Inefficient biting and chewing	Eating difficulties	3 5 6
Trauma	Increased risk of dental injury	Tooth damage	3 5

Table 1: Key Symptoms

Visible Protrusion of Upper Teeth

The most recognizable sign of overjet is the way the upper front teeth jut out beyond the lower teeth. This can be mild or quite pronounced, affecting the way a person looks and the way their teeth align when biting down. Some studies note that the degree of protrusion can vary by dental arch type, with tapered arches often showing greater overjet than ovoid or square forms 1.

Speech and Chewing Difficulties

Overjet can interfere with the natural mechanics of speech. Sounds like “s” and “f” may be harder to pronounce clearly. Additionally, the misalignment can make it challenging to bite into certain foods or chew efficiently 3 5 6. Children, in particular, may notice these issues as their permanent teeth come in.

Increased Risk of Dental Trauma

Teeth that extend far forward are simply more exposed—and more likely to be injured during falls or accidents 3 5. This is especially relevant for kids and adolescents who are active in sports.

Types of Overjet

Not all overjets are created equal. Understanding the various forms helps tailor treatment and predict outcomes.

Type	Defining Feature	Typical Patient	Source(s)
Dental	Tooth position; jaws aligned	Children, adults	3 5 6
Skeletal	Jaw bone discrepancy	Growing children	2 3 5
Arch-Related	Linked to arch shape (tapered, etc.)	Normal occlusion	1

Table 2: Overjet Types

Dental Overjet

This form results primarily from the positioning of the teeth themselves, not the underlying jaws. It can occur in both children and adults and is often responsive to orthodontic correction 3 5 6.

Skeletal Overjet

Here, the main problem lies with the bones of the jaw—either the upper jaw (maxilla) protrudes or the lower jaw (mandible) is set back. This skeletal discrepancy is often identified in growing children and may require early intervention or orthopedic appliances to correct 2 3 5.

Arch-Related Variations

Recent research highlights how the shape of the dental arch (tapered, ovoid, square) influences the amount and distribution of overjet. Tapered arch forms tend to have greater overjet, particularly in the anterior (front) teeth, compared to other arch shapes 1.

Causes of Overjet

Understanding the root causes of overjet can help in both prevention and treatment.

Cause	Description	Modifiability	Source(s)
Genetics	Inherited jaw/tooth structure	No	1 2 5
Habits	Thumb sucking, pacifier use, tongue thrusting	Yes	3 5 6
Growth Patterns	Abnormal jaw growth (skeletal issues)	Partially	2 4 5
Arch Form	Shape and size of dental arch	No	1

Table 3: Major Causes of Overjet

Genetic and Skeletal Factors

Many cases of overjet are driven by genetics. If a parent has a prominent overjet, their child may inherit the same jaw or tooth structure. Skeletal factors, such as underdevelopment of the lower jaw or over-development of the upper, are also significant contributors 1 2 5.

Oral Habits

Certain behaviors in childhood can push the upper teeth forward or impede the growth of the lower jaw. Common culprits include prolonged thumb sucking, pacifier use beyond infancy, and tongue thrusting during swallowing 3 5 6. Addressing these habits early can reduce the risk of developing severe overjet.

Abnormal Growth Patterns

Sometimes, discrepancies in the way the jaws grow—due to genetics or environmental factors—result in misalignment. Early identification during childhood is key, as some growth patterns can be influenced or redirected with orthodontic appliances 2 4 5.

Dental Arch Shape

The width and depth of the dental arch itself can affect how much the front teeth protrude. Tapered arches, in particular, are associated with a greater degree of overjet 1.

Treatment of Overjet

Modern dentistry offers a range of solutions for overjet, from removable devices to complex orthodontic appliances.

Treatment	Mechanism/Approach	Best For	Source(s)
Functional Appliances	Guide jaw growth/teeth	Children with skeletal issues	3 4 5 6
Elastodontic Devices	Flexible aligners	Mild-moderate overjet	6
Fixed Appliances	Braces, Herbst device	Predictable, efficient results	5
Early Orthopedic Intervention	Headgear, facemask	Skeletal discrepancies (young children)	2
Retention/Relapse Prevention	Retainers, overcorrection	All patients post-treatment	2 3 6

Table 4: Overjet Treatment Options

Functional Orthodontic Appliances

Devices like the Twin-block, Andresen activator, and prefabricated functional appliances (PFA) are designed to encourage proper jaw growth and tooth alignment, especially in children and adolescents. While both Twin-block and Andresen activator can reduce overjet, success rates often depend on patient compliance. Studies show no significant difference in effectiveness between these appliances, but compliance issues can impact results 3 4 5.

Twin-block vs. Hanks Herbst

The Hanks Herbst appliance, a fixed device, has been shown to reduce overjet more efficiently and predictably than the removable Twin-block. However, it requires more routine and emergency visits, and chairside time is greater. Twin-block users, meanwhile, experience more discontinuation and a greater decline in oral health-related quality of life, likely due to the removable nature of the appliance 5.

Elastodontic Devices

Flexible devices such as the Equilibrator Series II and Occlus-o-Guide are effective in reducing overjet and overbite, particularly in growing children. The Equilibrator Series II, in particular, has shown significant improvement over the Occlus-o-Guide in some studies. Elastodontic devices also support comprehensive patient management and help minimize relapse 6.

Early Orthopedic and Orthodontic Interventions

For skeletal overjet—where the jaw bones themselves are misaligned—early intervention is crucial. Facemask protraction headgear can improve the maxillomandibular relationship and significantly reduce overjet in young children. Overcorrection during treatment is often recommended to maintain the results over time 2.

Predicting Treatment Success

The initial overbite and the SNB angle (a measure of jaw position) are strong predictors of overjet correction success with functional appliances. A greater overbite at the start predicts more reduction in overjet. Understanding these predictors helps orthodontists tailor treatment and set realistic expectations 4.

Retention and Prevention of Relapse

After achieving the desired overjet reduction, retention is vital to prevent relapse. Overcorrection and the use of retainers are common strategies to maintain long-term results 2 3 6.

Conclusion

Overjet is a common but treatable dental condition with diverse symptoms, types, causes, and effective treatment options. By understanding the underlying factors and available therapies, patients and caregivers can make informed decisions for lifelong oral health.

Key Takeaways:

• Symptoms: Overjet primarily causes protruding upper teeth, with possible impacts on speech, chewing, and injury risk 1 3 5 6.
• Types: Overjet can be dental, skeletal, or related to arch form, each requiring tailored intervention 1 2 3 5 6.
• Causes: Genetics, oral habits, abnormal jaw growth, and arch shape all play roles in overjet development 1 2 3 4 5 6.
• Treatment: Functional and fixed appliances, elastodontic devices, and early orthopedic interventions are available; success depends on factors like patient compliance and initial severity 2 3 4 5 6.

Early detection and a personalized treatment plan are essential for optimal results. If you or your child shows signs of overjet, consult a dental professional to explore the best path forward.