An overbite is how far your upper front teeth overlap your lower front teeth from top to bottom. An overjet is how far the upper front teeth stick out in front of the lower ones. Both can be corrected, but they often need different approaches.
People use the two words interchangeably, and that is where most of the confusion starts. When someone says their child has “buck teeth,” they usually mean an overjet. When a dentist mentions that the lower front teeth disappear behind the upper ones, that is an overbite. Here is how to tell them apart and how each one is treated.
What Is the Difference Between an Overbite and an Overjet?
An overbite is a vertical measurement: how much of the lower front teeth is covered by the upper front teeth. A small amount of overlap is normal and healthy. When the upper teeth cover the lower teeth almost completely, orthodontists call it a deep bite, and in some cases the upper teeth can cut into the lower gums.
An overjet is a horizontal measurement: the gap between the front surface of the lower teeth and the back of the upper teeth, measured front to back. When that gap is large, the upper front teeth sit well forward of the lower ones and look like they are sticking out. This is the pattern most people picture when they think of protruding teeth.
A person can have one without the other, or both at once. Plenty of patients with a large overjet also have a deep overbite, because the lower front teeth have no upper teeth to stop against and keep erupting upward. That combination is one of the most common bite problems orthodontists see, and it is one of several covered in our overview of common bite problems in children and adults.
| Question | Overbite (deep bite) | Overjet (protrusion) |
|---|---|---|
| Which direction is the problem? | Vertical: upper teeth cover too much of the lower teeth | Horizontal: upper teeth sit too far in front of the lower teeth |
| How does it look from the front? | Lower front teeth are hidden when you bite down | Upper front teeth appear to stick out |
| What can it affect? | Lower gums, wear on front teeth, jaw comfort | Risk of chipping front teeth, lip closure, appearance |
| What usually causes it? | Jaw growth pattern, over-erupted front teeth | Jaw growth pattern, thumb sucking, tongue habits |
| Common orthodontic tools | Braces or aligners that level the teeth, sometimes TADs | Braces with elastics, growth guidance in children |
What Causes an Overbite or Overjet?
Most cases come down to how the upper and lower jaws grow relative to each other. If the lower jaw is set back compared with the upper jaw, the front teeth end up too far apart front to back, which shows up as an overjet. Family patterns play a role here, since jaw size and shape are inherited.
Habits can make things worse. Thumb or finger sucking that continues after the permanent front teeth start coming in can push the upper teeth forward and widen an overjet. A tongue that pushes forward when swallowing can have a similar effect. Our article on childhood habits that can lead to crooked teeth covers what parents can watch for at home.
Why Do Overbites and Overjets Need Treatment?
A large overjet leaves the upper front teeth exposed. Without the lower lip resting over them, they are more likely to be chipped or broken in a fall or a ball to the face. Some children with a large overjet also find it hard to close their lips comfortably.
A deep overbite causes a different set of problems. When the upper teeth cover the lower teeth too much, the lower front teeth can bite into the gum tissue behind the upper teeth, and the front teeth can wear down over time. The bite can also put extra load on the jaw joints. These changes tend to build slowly over the years.
How Do Orthodontists Fix an Overbite?
For most patients, braces or clear aligners correct a deep overbite by changing the vertical position of the front teeth. The teeth are leveled so the upper and lower front teeth overlap by a healthy amount instead of a deep one. With braces, the archwires do much of this work over the course of treatment. Speaks Orthodontics offers both metal and ceramic brackets, and you can compare them on our types of braces page.
Some deep bites need more control than braces alone can provide. Temporary anchorage devices, or TADs, are miniature implants placed in the bone of the upper or lower jaw. They give the orthodontist a fixed point to move teeth in a difficult direction while limiting unwanted movement of the other teeth. TADs are not needed for every overbite, but they can be useful when the front teeth need to move in a way the rest of the arch cannot support.
In growing children, treatment can also guide the way the jaws develop. That is one of the reasons early evaluation matters so much. The goal is to correct the relationship between the jaws while growth can still be influenced, rather than waiting until the bite is fully set.
How Do Orthodontists Fix an Overjet?
Because an overjet is usually a front-to-back problem between the jaws, treatment focuses on bringing the upper and lower teeth closer together in that direction. With braces, small rubber bands called elastics are stretched between the upper and lower teeth to shift the bite. Elastics only work when they are worn as directed, which is why our article on why elastics are important is worth reading before treatment starts.
Can Early Treatment Help a Child With an Overjet?
Often, yes. Two-phase treatment is designed to help the jaw develop in a way that accommodates the permanent teeth and improves how the upper and lower jaws fit together. Children over the age of six who show a jaw discrepancy can be candidates for early treatment. Correcting a large overjet early can also reduce the chance of an injury to the front teeth while the child waits for a second phase.
For adults, the jaws are no longer growing, so treatment relies on moving the teeth within the existing jaw structure. Most adult overjets can be improved with braces and elastics. When the difference between the jaws is too large for teeth to make up, orthodontic treatment can be combined with surgery to reposition the jaw, and an orthodontist will explain whether that is something to consider.
When Should You See an Orthodontist About Your Bite?
The American Association of Orthodontists recommends that children have their first orthodontic evaluation by age 7. By then, an orthodontist can usually see whether the jaws are growing in balance and whether the front teeth are heading toward an overjet or a deep bite. Many children only need to be monitored.
Adults do not need to wait for a referral either. If your lower front teeth vanish behind your upper teeth, if you notice wear on your front teeth, or if your upper teeth feel like they stick out, an exam can tell you which problem you have and what correcting it would involve. Dr. Clif Speaks is a board-certified orthodontist, certified by the American Board of Orthodontics, and he treats children, teens, and adults at our Denver office.
Frequently Asked Questions
Is an overbite the same as buck teeth?
Not exactly. “Buck teeth” usually describes an overjet, where the upper front teeth stick out horizontally. An overbite is the vertical overlap of the upper teeth over the lower teeth. Many people have some of both.
Is a small overbite normal?
Yes. A slight overlap of the upper front teeth over the lower front teeth is part of a healthy bite. Treatment is considered when the overlap is deep enough to hide the lower teeth or affect the gums.
Can clear aligners fix an overbite or overjet?
Clear aligners can correct many mild to moderate cases. More complex bite problems may be better suited to braces. Your orthodontist will recommend the option that fits your bite after an exam with X-rays.
What happens at the first visit?
Your initial consultation includes a review of your dental and medical history, a complete oral exam with X-rays, and a discussion of your treatment options, costs, and payment plans.
Find Out Which Bite Problem You Have
An overbite and an overjet can look alike in the mirror, but they are treated differently. A complimentary exam at Speaks Orthodontics will show which one you or your child has and whether braces in Denver or another option makes the most sense. Schedule your complimentary exam to get started.