Overbites vs. Underbites: What are the Differences?

To achieve strong oral health and a wonderful smile, your upper and lower jaws need to evenly meet. This allows you to do things like eating and swallowing with ease and avoid some very serious health risks to your jaw, mouth and teeth.

A malocclusion is whenever the upper and lower rows of teeth do not meet. There are three types of malocclusions: overbites, underbites and crossbites. Overbites and underbites are the most common but all three require immediate and thorough orthodontic treatment. It can be tricky to know if you have a severe enough overbite or underbite to warrant orthodontic intervention.

How do you go about fixing your overbite or underbite? How do the treatments differ? What can you expect from the various treatments? As you can imagine, there are a lot of questions that you need answered. To start, let’s review the basics of identifying overbites and underbites. Then, we’ll explore treatment options and the best courses of action with respect to dealing with your malocclusion before the problem worsens.

What is an Overbite?

Just because your upper teeth extend somewhat over your lower teeth, doesn’t necessarily mean you have an overbite. In addition, minor overbites are very common and might not require braces. Overbites that are severe enough to need fixing occur when the upper teeth overlap the bottom teeth to an excessive degree of roughly 4 to 10 millimeters. This can be caused by genetics, a recessive chin, misaligned bites, thumb sucking, poorly fitted crowns, gum disease or as the result of injury. Also, sometimes teeth just come in awkwardly.

Overbites are more common than underbites and are called a Class II bite. One thing to remember is that having a slight overbite is normal because the shape of the human skull naturally allows for the upper teeth to extend beyond the lower teeth. During checkups, your dentist should measure your overbite and underbite and consult with you if they suspect any issues.

The good news is that overbites are considered to be easily treatable using conventional methods. It is easier to fix in young children so don’t hesitate to speak with an orthodontist immediately about your child or children’s potential malocclusion. It’s never too late to fix this issue if the patient is willing.

What is an Underbite?

An underbite, a Class III bite, is when the lower teeth extend beyond the upper. Essentially, the lower jaw protrudes, making it impossible for the lower row of teeth to align with the upper row causing the potential for several serious oral health issues. This can be caused by the upper jaw bone being underdeveloped or the bone in the lower jaw being overdeveloped.

Like overbites, underbites can begin during childhood due to behaviours like thumb-sucking or caused by genetics or as the result of an accident. Whatever the cause, severe underbites should be treated immediately as to avoid the potential hazards that can surface over time.

What is a Crossbite?

Most people believe there are only two malocclusions. There is a third type, though, known as a crossbite. And while it is less common, it still requires diagnosis and treatment. Crossbite is a lateral misalignment meaning the top teeth are positioned too close to the cheek or tongue.

Crossbite occurs during childhood and doesn’t naturally correct itself over time. It can occur between the front or back teeth. The side effects are similar to and just as serious as overbites and underbites. Upon diagnosis, your dentist should present treatment options and recommend a course of action.

Do you Have a Misaligned Bite?

While you can do a remedial check to see if you exhibit the signs of having a misaligned bite, this is a job best left to your dentist or orthodontist. They will conduct an inspection that looks for:

  • Misaligned teeth
  • Abnormal facial structure
  • Difficulty with chewing or biting
  • Speech impediments like a lisp

If a dentist spots any of the above symptoms, they will most likely refer you to an orthodontist to begin the conversation about treatment options.

Health Risks Associated with Malocclusion

Overbites and underbites are very serious and can lead to:

  • Increased risk of tooth decay, breakage, cavities and gingivitis
  • Jaw strain
  • Headaches
  • Earaches

There are also mental health and self-esteem risks associated with overbites and underbites. This is often overlooked but our appearance can inform how we feel and determine our emotional state. We believe that dentistry should help you feel confident and comfortable with your smile.

Overbite and Underbite Treatments

Your orthodontist will determine the best course of action to treat your misaligned bite.

Treatment options include:

Removable Retainer

For less severe bites, a removable retainer is a suitable enough solution to produce the desired results. This type of retainer hooks around the back teeth to hold itself securely in place. The removable element makes it easier to clean your teeth but the patient must be responsible enough to remember to put it in every day. Forgetting for long stretches would negate this treatment’s effectiveness.

Despite its appeal, if you cannot handle the daily responsibility of wearing a removable retainer than it might not be the option for you.


The most common way to treat misaligned bites is with braces or aligners, especially with children or teenagers. Braces use taut wires to connect tiny brackets to apply consistent pressure to teeth. This forces them to realign and straighten over time. Braces have a high success rate but can be pricy and patients must wear them for anywhere between one to three years.

If you need more incentive to deal with a misaligned bite early, keep in mind that insurance providers often cover braces for children but not adults. We always recommend speaking with your insurance provider to discuss your coverage and payment options.


Some cases of misaligned bites only require aligners. Popular options like Invisalign, which are clear and removable, work wonders while allowing people to go about their day with minimal interruption or embarrassment. Invisalign isn’t an appropriate solution for every case of malocclusion so ask your dentist if they make sense for your situation.

Treatment duration depends on the severity of your issue but be prepared to commit for several months if not a year or two. It might sound as if treatment will upend your life but it is worth it for both your oral health and the smile you will achieve and get to show off every day. Your dentist should be well equipped to talk you through the emotional impact of these procedures and help prepare you for any changes to your daily life.

Get Help for your Misaligned Bites

Don’t wait and let your overbite, underbite or crossbite worsen and create additional issues for your mouth, teeth and gums. Letting these problems linger can result in you needing caps, crowns or dental hardware installed. Furthermore, neglect can make them harder to fix down the road.

We hope this article has answered some of your questions about overbites and underbites. If you or your child needs treatment, then remember just about any misaligned bite can be repaired. It’s always better to tackle the problem head-on and immediately.

Book your free, no-obligation consultation today and learn how Barrie Dentist can get your smile back in style!

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