Overbite vs. Overjet: How Can You Tell the Difference - and Can Clear Aligners Help?

Did you know that while the terms overbites and overjet may be used interchangeably, they are distinct from one another? Here, our Mount Pearl dentists explain the differences between the two and how we can correct either issue using clear aligners.

What are overbites and overjets?

Overbites and overjet are two very common orthodontic issues. Though the terms are often used interchangeably, there are distinct differences between these two conditions.


Overbites are sometimes called deep bites and can happen when one-third of a patient's lower incisors are covered by their upper front teeth when their jaw is closed. This issue is a vertical misalignment, rather than a horizontal one such as an overjet.


Commonly called “buck teeth” an overjet is when the upper front teeth protrude over the bottom teeth, creating a significant horizontal overlap.

It's normal for the upper front teeth to rest a bit in front of your lower teeth with your mouth closed. However, any space greater than 2 millimetres will cause issues. 

Overbites are vertical, while overjets are horizontal and cause the upper teeth to protrude past the bottom teeth at an angle. But with an overbite, the teeth remain downward or straight (not on an angle).

How are overbite and overjet caused?

The most common causes of overbites are when the lower jaw is somewhat smaller than the upper jaw, causing the lower teeth to rest behind the upper and teeth and move downwards as your teeth wear down abnormally.

More gum will tend to show on your upper teeth, and your upper front teeth sit slightly lower than the teeth beside them (upper side teeth, or canines).

Overbites can occur if a patient had a tongue-thrusting habit or was permitted to suck on an object - usually a pacifier or thumb - for too long as a child. Biting the nails or chewing on objects such as erasers or pens can also cause this issue.

Childhood habits like thumb-sucking or nail-biting may cause overjet, similar to overbites if they continue when adult teeth start to emerge. Another common issue is that the lower jawbone doesn't keep up with the development of the upper jawbone. This disparity in growth will cause the lower jawbone and teeth to be situated further back than where they should be in an ideal smile.

Genetic factors can also cause overbite or overjet.

What dental problems can overbite and overjet create?

In extreme cases of overbite, the lower teeth may touch the gum tissue behind the upper front teeth, creating wear on the teeth and gum tissue.

When it comes to overjets, the risk for damaging your teeth or featuring them can increase. Some overjets are moderate and barely noticeable, while other may be much more severe and make it difficult to close your lips because of poor tooth alignment. You may also notice challenges when biting or chewing. 

Can an overbite or overjet be treated with clear aligners?

If the overbite or overjet is skeletal in nature, we would not recommend clear aligners and instead suggest speaking to your dentist to explore other options, such as surgery.

If your overbite or overjet is caused by one o the above issues, we may be able to use clear aligners to treat the problem. These aligners will apply gradual pressure to your teeth in order to move them into their correct positions as prescribed by your dentist in a custom treatment plan. This can result in a straighter and more symmetrical smile.

The clear aligners also move your gum at the same time, keeping proportions in check. You will need to wear your clear aligners for about 22 hours each day, removing them to brush, floss, eat and drink.

Your teeth will progressively shift with the aligners, and you’ll switch to a new set approximately every two weeks. Your custom treatment plan could involve wearing as many as 26 trays, which equates to one tray every two weeks for 12 months.

Before starting your treatment, your dentist will be able to show you a preview of how your new smile will look by the end of your treatment. Take your first steps to schedule a consultation with your dentist and learn if you are a good candidate for clear aligners. 

Would you like to find out whether clear aligners would help fix your overbite or overjet? Contact our Mount Pearl dentists to book a consultation today.

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