One of the most common questions we’re asked in orthodontic consultations, and one of the most searched topics online, is overbite vs underbite.
Patients often come to see us because they may have noticed their upper teeth stick out, or their lower jaw looks prominent, or their bite just doesn’t feel quite right.
Naturally, they want to understand what this means and whether treatment is needed.
Before we dive in, there’s an important clarification that helps explain much of the confusion around this topic.
A Quick Clarification : Overbite vs Overjet (Why These Terms Are Often Confused)
When people search online for “overbite vs underbite”, they are very often actually describing a condition called an overjet.
In simple terms :
- Overbite refers to how much the upper teeth overlap the lower teeth vertically
- Overjet refers to how far the upper teeth sit in front of the lower teeth horizontally
- Underbite is when the lower teeth sit in front of the upper teeth
In everyday language, the word overbite is commonly used to describe upper teeth that stick out.
Orthodontically, however, this is usually an overjet, not an overbite.
This means :
- You can have a large overjet without having a deep overbite
- You can have a deep overbite even if your upper teeth don’t protrude
Both overbite and overjet are different from an underbite
In this article, we’ll use the commonly searched term overbite where helpful, while also explaining the correct orthodontic terminology, so you can clearly understand your bite and the treatment options available.
If this feels confusing, you’re not alone.
Many patients use these terms interchangeably, and part of our role as orthodontists is to clarify exactly what’s going on with your bite.
What Is an Overbite?
An overbite occurs when the upper front teeth overlap the lower front teeth when biting together.
A small amount of overlap is completely normal and forms part of a healthy normal occlusion.
In fact, a slight overbite helps protect the back teeth and supports efficient chewing.
An overbite becomes a concern when the overlap is excessive, resulting in a dental malocclusion.
A significant overbite may be associated with :
- Excessive tooth wear
- Trauma to the lower teeth
- Gum irritation
- Jaw discomfort
- Changes in lip posture or facial balance
- An increased overjet (upper teeth sitting too far forward)
What Is an Underbite?
An underbite occurs when the lower teeth sit in front of the upper teeth when biting together.
This is also known as a Class III dental malocclusion.
Underbites often involve a mismatch between the jaws, such as :
- A forward-positioned lower jaw
- A smaller or underdeveloped upper jaw
- Or a combination of both
- An underbite may also occur alongside:
- A crossbite
- An open bite
- Other forms of dental malocclusion
Clinically, underbites can affect chewing efficiency, tooth wear, speech, facial profile, and long-term jaw health.
Overbite vs Underbite : What’s the Difference?
The key difference between overbite vs underbite lies in how the teeth and jaws relate to each other.
- Overbite : Upper teeth overlap the lower teeth too much
- Underbite : Lower teeth sit in front of the upper teeth
- Normal occlusion : Upper teeth gently overlap the lower teeth in a balanced way
When orthodontists compare underbite vs overbite vs normal, we assess :
- Tooth position
- Jaw relationship
- Facial profile (side view)
- Bite function and wear patterns
- X-ray findings showing jaw growth and tooth position
Although these are opposite bite problems, both can lead to functional and dental issues if left untreated.
Is an Overbite or Underbite a Problem?
A very common question we hear is :
“Is an overbite worse than an underbite?”
Neither is automatically worse. What matters most is severity, jaw involvement, and function.
Both overbites and underbites can contribute to :
- Tooth wear and chipping
- Gum recession
- Jaw strain or discomfort
- Difficulty biting or chewing
- Changes to facial balance and profile
A severe overbite or underbite is more likely to cause long-term dental and jaw problems, which is why early assessment is important.
Treatment Options for Overbite and Underbite
Correcting a bite involves more than simply straightening teeth.
Orthodontic treatment focuses on achieving a stable, healthy occlusion that will last long term.
Overbite correction may include :
- Braces or clear aligners
- Bite-correcting mechanics
- Elastics
- Growth-guidance appliances in children
- In selected severe adult cases, jaw surgery
Underbite treatment may include :
- Braces or aligners
- Upper jaw expansion
- Orthopaedic appliances in growing patients such as facemasks or expanders
- Combined orthodontic treatment and jaw surgery for severe skeletal cases
Many patients ask :
- Can braces fix an overbite? – Yes, in many cases
- Can braces fix an underbite? – Yes for mild to moderate cases; severe cases may require surgical input
Every treatment plan is individualised and based on careful diagnosis.
Overbite vs Underbite in Children vs Adults
Children
- Jaw growth can be guided
- Early intervention may reduce severity
- Appliances can influence jaw development
- Early treatment may reduce the need for surgery later
Adults
- Jaw growth is complete
- Treatment focuses on tooth movement and bite correction
- Some skeletal discrepancies may require jaw surgery
- Many adult cases can still be treated without surgery
This is why an orthodontic assessment is recommended even if treatment doesn’t start immediately.
When to See an Orthodontist
You should consider seeing an orthodontist if :
- Upper teeth appear to stick out
- Lower teeth sit in front of the upper teeth
- The bite looks uneven from the side profile
- Teeth are wearing unevenly
- Chewing feels uncomfortable
- A child’s bite doesn’t appear to be developing normally
A specialist orthodontist assesses not only the teeth, but also jaw position, facial balance, bite relationship, and long-term dental health, often supported by X-rays.
Frequently Asked Questions About Overbite and Underbite
1. What is the difference between an overbite and an underbite?
An overbite involves excessive overlap of the upper teeth, while an underbite occurs when the lower teeth sit in front of the upper teeth.
2. What causes an overbite or underbite?
Genetics, jaw growth patterns, habits, airway factors, and early tooth loss may play a role.
3. Can an overbite or underbite correct itself over time?
Significant bite problems rarely correct themselves and may worsen without orthodontic guidance.
4. How do I know if I have an overbite or underbite?
If you notice excessive overlap, protruding upper teeth, a reversed bite, or facial imbalance, an orthodontic assessment is recommended.
5. Do overbites and underbites cause health problems?
Yes. Untreated bite problems can lead to tooth wear, gum issues, jaw strain, and functional difficulties.
Final Thoughts from Dr Doreen
Overbites and underbites are not just cosmetic concerns, they may affect jaw health, tooth longevity, facial balance, and long-term function.
The goal of orthodontic treatment is not simply straight teeth, but a stable, healthy, and functional bite that supports a confident smile for life.
If you’re unsure whether your bite is normal or needs assessment, a consultation with a specialist orthodontist is the best first step.
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