People often use the terms overjet and overbite interchangeably, but they are two different conditions. In this blog, our Vancouver dentists share the differences between overjets and overbites and how they could be treated with clear aligners.
What is the difference between overbites and overjets?
Overbites and overjets are among the orthodontic issues our dentists see most often. These terms are frequently used interchangeably, but there are various differences between the two conditions.
Overbite
An overbite could also be called a deep bite which occurs when one-third of the lower incisors are covered by the upper front teeth while your jaw is in a closed position. The vertical nature of this issue distinguishes it from an overjet, which is horizontal.
Overjet
Often called “buck teeth” an overjet happens when the upper front teeth protrude over the bottom teeth, causing a significant horizontal overlap.
While it’s normal for the upper front teeth to sit slightly in front of your lower teeth when your mouth is closed, any space larger than 2 millimetres will lead to problems.
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).
What causes overbites and overjets?
The most common cause of an overbite is when the lower jaw is slightly smaller than the upper jaw, making the lower teeth rest behind the upper teeth, moving downwards as the teeth begin to wear down.
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 could develop when a patient had a tongue-thrusting habit or was allowed to suck on an object - typically a pacifier or thumb - for too long as a child. Nail-biting or chewing on items such as erasers or pens can also lead to this condition.
Like overbites, childhood habits such as finger or thumb sucking can cause overjet if they continue when adult teeth start emerging. Another common cause is when the lower jawbone (mandible) doesn't keep up with the development of the forward growth of the upper jawbone (maxillary). This disparity in growth leads to the bottom jawbone (and consequently the teeth), moving behind where it should be situated for an ideal smile.
Genetic factors may also cause an overbite or overjet.
What dental problems can an overbite or overjet cause?
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.
If you have an overjet you are at a higher risk for damaging or fracturing your teeth. Some overjets are barely noticeable as they are moderate, while others are more severe and can make it hard to fully close your lips because of the poor alignment of teeth. You might also notice challenges with chewing or biting.
Can overbites or overjets be corrected with clear aligners?
If the overbite or overjet is skeletal in nature, we would not recommend clear aligners and instead suggest talking to your dentist about exploring other options, such as surgery.
But, if your overjet or overbite is caused by one of the issues mentioned above, your dentist might be able to fix your condition with clear aligners. The aligners will apply gradual pressure to your teeth to shift them into corrected positions as prescribed by your dentist in a custom treatment plan. This should give you a straighter, more symmetrical smile.
The clear aligners also move your gum at the same time, keeping the proportions in line. 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 you start your treatment, your dentist will be able to show you a preview of how your smile could look at the end of your treatment. Take the first step by scheduling a consultation with your dentist to learn if you are a candidate for clear aligners.