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Overbite vs. Overjet: How Can You Tell the Difference?

Overbite vs. Overjet: How Can You Tell the Difference?

Did you know the terms overbite and overjet are often used interchangeably, but that they are distinct from each other?  Our Toronto dentists (at our King-York Dental, Bay Adelaide Dental, Brookfield Place Dental, Richmond-Adelaide Dental and College Park Dental locations) explain the difference and how we may be able to correct either issue with Invisalign clear aligners.

What are overbites and overjets?

Overbites and overjets are two of the most common Orthodontic Issues. Though the terms are often used interchangeably, there are distinct differences between these two conditions.


An overbite can also be referred to as a deep bite, and happens when one-third of the lower incisors are covered by the upper front teeth while your jaw is in a closed position.

Overbites are vertical and the teeth remain downward or straight.


An overjet is when the upper front teeth protrude over the bottom teeth creating a significant horizontal overlap, commonly referred to as “buck teeth”. 

While it’s normal for upper front teeth to rest slightly in front of your lower teeth when closing your mouth, any space of more than 2 millimetres will cause issues.

 Overjets are horizontal and cause the upper teeth to protrude past the bottom teeth at an angle. 

How are overbite and overjet caused?

The most common cause for overbite is that the lower jaw is somewhat smaller than the upper jaw. This results in the lower teeth resting behind the upper teeth and moving downwards as wear on your teeth takes place. 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.

Similar to overbites, childhood habits such as finger or thumb sucking can cause overjet if the habit persists when adult teeth begin to emerge causing a horizontal angle of the teeth. 

Another common cause for overjet is that the lower jawbone (mandible) fails to keep up with the development of the forward growth of the upper jawbone (maxillary). This disparity in growth results in the bottom jawbone (and consequently the teeth), ending up situated behind where they should be for an ideal smile.

Overbite and overjet can also be caused by genetic factors.

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.

With an overjet, your risk for damaging your teeth or fracturing them increases. Some overjets are barely noticeable as they are moderate, while others are more severe and can make it difficult to close your lips completely due to poor alignment of teeth. You may also notice challenges with chewing or biting.

Can an overbite or overjet be treated with Invisalign clear aligners?

If the overjet or overbite is caused by one of the issues listed above, we may be able to treat the problem with clear aligners. The aligners will apply gradual pressure to your teeth to move them into corrected positions as prescribed by your dentist in a custom treatment plan. This will leave you with a straighter, more symmetrical smile.

However, if the overbite or overjet is skeletal in nature clear aligners are not recommended.  Your dentist will explore other options with you, such as surgery.

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.

The clear aligners also move your gum at the same time, keeping proportions in check.

Before you start 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 the first step to schedule a consultation with your dentist to learn if you are a candidate for Invisalign lear aligners.

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

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Since 2001, Toothworks Dental Clinics have been providing patients of all ages with personalized dental care and a welcoming experience at locations across Ontario.

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