What Is an Underbite? Causes, Risks and Treatment Options

 

A confident smile can change the way you feel about yourself every single day. But for many people, dental conditions like an underbite can affect not just their appearance, but their overall oral health and quality of life. The good news? Underbites are very treatable — and the earlier you act, the better the outcome.

In this article, we break down everything you need to know about underbites: what causes them, the risks of leaving them untreated, and the most effective ways to correct them for a healthier, happier smile.

What Is an Underbite?

An underbite is a type of dental misalignment where the lower teeth and jaw protrude in front of the upper teeth when the mouth is closed. Also referred to as a Class III malocclusion or a ‘reverse bite’, an underbite can range from very mild — where the misalignment is barely visible — to quite severe, where the lower jaw juts noticeably forward, creating a concave facial profile.

While underbites are relatively uncommon compared to other bite issues, they can have a significant impact on a person’s oral health, speech, and self-confidence when left unaddressed.

What Causes an Underbite?

There are several reasons why someone might develop an underbite. Understanding the cause is an important first step toward choosing the right treatment.

• Genetics is the most common cause. If an underbite runs in your family, there is a good chance you may have inherited the same jaw or tooth alignment. DNA plays a significant role in determining the size and shape of your jaw, and unfortunately, this is not something you can prevent. However, an inherited underbite can absolutely be treated with the right orthodontic care.
• Facial injuries can also lead to an underbite. Trauma to the jaw — such as from a sporting accident or a fall — can damage the bone structure in a way that causes the lower jaw to shift out of alignment. Even after surgical repair, the teeth may not sit correctly, which can result in a post-injury underbite.
• Tumours of the mouth or jaw, while very rare, are another possible cause. In some cases, abnormal growths can affect how the jaw develops and aligns over time.
• In children, certain childhood habits such as prolonged thumb sucking, extended use of a dummy, or persistent tongue thrusting can also contribute to the development of an underbite over time.

What Are the Risks of an Underbite?

A mild underbite may not cause immediate problems, but a moderate to severe underbite — especially one that is left untreated — can lead to a range of oral health issues over time.

Some of the most common risks include difficulty biting and chewing food properly, as well as speech difficulties such as a lisp or trouble pronouncing certain sounds. Many people with an underbite also experience chronic jaw pain, headaches, or discomfort related to the misalignment of the temporomandibular joint (TMJ).

An underbite can also wear down tooth enamel faster than normal, increasing the likelihood of chips, cracks, or broken front teeth. In some cases, the misalignment creates hard-to-clean areas in the mouth, leading to a higher risk of tooth decay, gum disease, and bad breath.

Can Wisdom Teeth Cause an Underbite?

This is a common question, and it is completely understandable why many people make this connection. Wisdom teeth typically emerge during the late teenage years or early adulthood — the same period when an underbite may appear to worsen due to natural growth spurts.

However, wisdom teeth do not cause underbites. The two issues simply coincide in timing. An underbite develops because of jaw structure and alignment — not because of the eruption of wisdom teeth. So if you are noticing your underbite getting more pronounced in your teens, it is more likely related to the growth of your jaw than to your wisdom teeth coming through.

What Age Should You Check and Fix an Underbite?

The ideal time to begin assessing and treating an underbite is during childhood, when the jaw bones are still developing and more responsive to intervention. The earlier an orthodontist can evaluate the condition, the more treatment options are available — and the more effective those treatments tend to be.

We recommend that children see a specialist orthodontist for an assessment from around the age of seven. Even if active treatment is not required right away, early monitoring means that the right treatment can be started at exactly the right time.

For adults, it is never too late to seek treatment for an underbite. While some options may be more complex for fully developed jaws, effective correction is still very much achievable.

Do Children Outgrow Underbites?

Unfortunately, children do not outgrow underbites. Because underbites are most commonly inherited, the arrival of adult teeth does not correct the underlying jaw alignment. In fact, the opposite tends to happen.

During puberty, particularly during periods of rapid growth, an underbite can become more pronounced. The lower jaw may grow more than the upper, making the chin appear more prominent and the facial profile more concave. This is exactly why early intervention matters — in many cases, treatment started during childhood can significantly reduce the severity of the underbite before it has a chance to worsen.

Can Braces Fix an Underbite?

Yes — braces and clear aligners can be a very effective treatment for underbites, particularly for mild to moderate cases. When combined with orthodontic elastics, they can help guide the jaw and teeth into better alignment gradually and comfortably over time.

That said, the right treatment depends entirely on the individual. A specialist orthodontist will carry out a thorough assessment — looking at the severity of the underbite, the age of the patient, and the overall structure of the teeth and jaw — before recommending the most appropriate course of action. An accurate diagnosis is essential an incorrect one can lead to incomplete or ineffective treatment, which is why it is always best to see a qualified specialist rather than a general dentist for bite-related issues.

How Can You Fix an Underbite?

There are several treatment options available for correcting an underbite, and the right approach will depend on the patient’s age and how severe the misalignment is. In most mild to moderate cases, surgery is not required.

• Upper jaw expander:
  

  If the upper jaw is narrow as well as misaligned, an upper jaw expander may be recommended. This device fits across the roof of the mouth and gently widens the upper jaw over time so that it better matches the lower jaw.

• Reverse-pull headgear (facemask):
  

  This appliance works by pulling the upper jaw forward and is most effective in younger patients — ideally under the age of 10 — while the bones are still soft and growing.

• Braces or clear aligners:
  

  Options such as Invisalign® similar systems can effectively treat underbites in both children and adults. When worn alongside orthodontic elastics, results can be even more significant.

• Tooth extraction:
  

  In some mild to moderate cases, carefully removing selected teeth can reduce crowding and help bring the remaining teeth into better alignment.

• Jaw surgery (orthognathic surgery):
  

  For adults with a severe underbite, surgery may be the most appropriate route to properly align the upper and lower jaws. This procedure is considered low risk, highly predictable, and is typically recommended in close collaboration between your specialist orthodontist and a maxillofacial surgeon.

The most important factor in successfully treating an underbite is getting the diagnosis right from the very beginning. Early action leads to better outcomes, simpler treatment, and a healthier smile for life

Take the First Step Towards Correcting Your Underbite

At Miranda Dental Centre, our friendly and experienced team is here to help you take that first step. We offer thorough underbite assessments for both children and adults, and will work with you to find the most effective treatment plan tailored to your individual needs — no matter how mild or severe your case may be.

Don’t put it off any longer. Book your Appointment today and let us help you achieve the healthy, confident smile you deserve.