Deep Bite: When Your Top Teeth Overlap Too Much

Editorially reviewed by the Dental.me Editorial Team · Updated July 2026

When you bite down naturally, your upper front teeth are supposed to rest slightly in front of and just over your lower front teeth. A little overlap is normal and healthy. But when the top teeth cover the bottom teeth by too much, sometimes hiding them almost entirely, that excessive vertical overlap is called a deep bite. It is one of the most common bite problems dentists see, and while it can look like a purely cosmetic issue, an untreated deep bite can quietly wear down your front teeth, irritate your gums, and strain your jaw over the years.

What is a deep bite?

A deep bite, also called a deep overbite, is a type of malocclusion, which simply means the teeth do not meet the way they ideally should. Specifically, it describes how much the upper front teeth vertically overlap the lower front teeth when the back teeth are closed together.

Everyone has some overlap. In a healthy bite, the top front teeth cover roughly the upper third of the lower front teeth. In a deep bite, that overlap becomes excessive, half or more of the lower teeth can disappear behind the uppers. In severe cases, the lower front teeth bite so far up that their edges press into the gum tissue behind the upper teeth or into the roof of the mouth, which can cause real damage over time.

Deep bite vs. overjet: two different things

People often mix up overbite and overjet, but they measure different directions. A deep bite (overbite) is about vertical overlap, how far the upper teeth come down over the lower ones. Overjet is horizontal, how far the upper front teeth stick out in front of the lower ones, the classic look people call “buck teeth.” You can have one, the other, or both. Deep bite is also distinct from other bite problems like an underbite, where the lower teeth sit in front, or a crossbite, where some teeth close on the wrong side. Our guide to overbite, underbite, and crossbite breaks down how each one differs.

What causes a deep bite?

Most deep bites trace back to genetics and the way the jaws are shaped and sized. Common contributors include:

• Skeletal jaw structure. A lower jaw that is small, short, or set back relative to the upper jaw lets the front teeth over-close. This is usually inherited and is the root cause in many cases.
• Missing or worn-down back teeth. Your back teeth act like posts that hold the bite at the right height. When molars are missing, short, or worn flat, the jaw over-closes and the front teeth crash together more deeply.
• Grinding and clenching. Chronic teeth grinding (bruxism) gradually flattens the chewing surfaces of the back teeth. As those surfaces lose height, the bite collapses and deepens over the years, one reason deep bites can worsen in adulthood.
• Childhood habits and eruption patterns. Prolonged thumb-sucking, tongue habits, and the way permanent teeth erupt can all influence how deep the bite settles as a child grows.

Why a deep bite is worth treating

A deep bite is easy to ignore because it rarely hurts at first. But the constant, heavy contact between the front teeth creates problems that build up:

• Accelerated tooth wear. The front teeth take forces they were not designed to absorb, so they chip and wear down faster. See what that looks like in our article on worn-down teeth.
• Gum and palate damage. When lower teeth bite into the gum behind the upper front teeth or into the roof of the mouth, they can create sore spots, notches, and long-term gum recession.
• Jaw strain, TMJ issues, and headaches. A collapsed bite can overload the jaw joints and muscles, contributing to soreness, clicking, and tension headaches.
• Cosmetic effects. A deep bite can make a smile look short or “gummy” because so little of the lower teeth shows and the face height is reduced.
• Risk to dental work. Crowns, veneers, and fillings on the front teeth are more likely to break under the heavy load of a deep bite.

How a deep bite is diagnosed

A dentist or orthodontist diagnoses a deep bite by examining how the teeth come together and measuring the vertical overlap of the front teeth. Just as important is figuring out why the bite is deep. Is it a dental problem, where the teeth have drifted or worn, or a skeletal one, where the jaws themselves are mismatched?

To answer that, the provider may take X-rays, photographs, and digital or physical models of your teeth. A cephalometric X-ray shows the relationship between the upper and lower jaws, which helps distinguish a mostly dental deep bite from a skeletal one. That distinction matters, because it shapes the entire treatment plan.

How a deep bite is treated

Treatment depends on the cause, the patient’s age, and how severe the overlap is. Orthodontics is the mainstay in almost every case.

Orthodontics: braces and clear aligners

The core fix is to “open” the bite by intruding (pushing in) the front teeth and repositioning them so the upper and lower teeth meet more evenly. Braces and clear aligners both do this, using controlled forces to move teeth over months. If you are curious about the mechanics, our explainer on how braces work covers it. Deep bites are also a frequent target of overbite correction more broadly, discussed in how to fix an overbite.

Guiding growth in children

In children who are still growing, catching a deep bite early gives the orthodontist a chance to guide jaw growth rather than just move teeth. Early, well-timed treatment can reduce how much correction is needed later and sometimes avoids more involved procedures in adulthood.

Restoring lost height and managing wear

When the deep bite comes from missing or worn back teeth, the fix may include building up short teeth or replacing missing molars to restore proper bite height. If grinding is driving the problem, a custom night guard protects the teeth and helps prevent the bite from collapsing further. A bite plate or similar appliance is sometimes used to help open the bite as well.

Jaw surgery for severe skeletal cases

For adults with a severe skeletal deep bite, where the jaw bones themselves are significantly mismatched, orthodontics alone may not be enough. In those cases treatment can combine braces or aligners with corrective jaw surgery to reposition the jaw. This is reserved for the more extreme situations and is planned jointly by an orthodontist and an oral surgeon.

Holding the correction: retention

A deep bite has a stubborn tendency to relapse. Teeth and jaws want to drift back toward their old position, and the same forces that created the deep overlap can pull it back. That is why retention is not optional. After active treatment, wearing a retainer as directed is what holds the new bite in place for the long term. Skipping the retainer is one of the most common reasons a corrected deep bite returns.

The takeaway

A deep bite is excessive vertical overlap of the upper front teeth over the lower ones. It is usually rooted in genetics and jaw structure, and it can be made worse by tooth wear, grinding, or missing back teeth. Left alone, it can wear the front teeth, damage the gums and palate, and strain the jaw, so it is worth addressing beyond appearance alone. The main treatment is orthodontics to open and realign the bite, with restorative work or, in severe skeletal cases, jaw surgery when needed, and a retainer to hold the result. If you think your top teeth overlap the bottom ones too much, or you notice front-tooth wear, sore spots on your gums, or jaw tension, see a dentist or orthodontist for an evaluation. A simple exam can tell you whether it is a deep bite and what, if anything, you should do about it.

Find care near you: compare dentists in your area, or browse dental specialties.