An underbite is a type of teeth misalignment where the lower teeth extend past the upper front teeth. It can range from a minor issue affecting only the teeth to more severe cases that impact the jaw. Causes of underbites include developmental issues, genetics, or childhood habits such as thumb-sucking or extended use of pacifiers.
Underbites may result in complications with speech, chewing, excessive tooth wear, and occasionally headaches and jaw pain. Treatment options include orthodontics and, in more severe cases, surgical procedures to reposition the jaw.
By Able Health I Medically reviewed by Dr. Alireza Estedlal
Page last reviewed: February 2024 I Next review due: February 2026
An underbite occurs when the lower teeth protrude forward compared to the upper teeth, making the lower jaw and teeth more prominent. This condition is relatively common, affecting about 5% to 10% of the population.
Most underbites result from an imbalance in the growth of the maxilla (upper jaw) and mandible (lower jaw). Many people with a minor underbite might not notice the issue. However, in severe cases, the space between the top and bottom teeth becomes more noticeable.
Several factors can contribute to the development of an underbite, including:
Not all underbites are equally severe. Mild underbites are often unnoticeable from the outside, while more severe underbites, where the lower jaw protrudes, are more visible.
Underbites can cause problems beyond appearance. Mild cases can lead to wear and tear on the misaligned anterior teeth, increasing the risk of breakage or chipping. Severe underbites can cause significant issues with speaking and chewing, especially if the jaw is misaligned.
If left untreated, an underbite could lead to:
There are several ways to correct underbites, and orthodontists often combine two or three different methods to achieve the best results. Your orthodontist will examine your teeth and jaw, discuss potential treatment options, and recommend a personalised plan.
Common treatment options for underbites include:
After treatment, additional orthodontic measures, such as retainers, may be needed to correct the bite and position of the teeth.
In some cases, dental extractions or interproximal reduction (dental filing) may be required to assist with tooth movement. Elastics are frequently used between the upper and lower braces to guide the teeth into their proper position.
The NHS provides metal braces to children under 18 who qualify for underbite treatment. Other options, such as clear ceramic braces, are available privately.
In cases where crowded teeth contribute to an underbite, your orthodontist may suggest removing one or more teeth. This creates more space for braces, helping them function properly. Extractions are usually performed under local anaesthesia by a dentist or oral surgeon, although general anaesthesia may be required for multiple extractions, such as wisdom teeth removal.
In severe cases, underbite surgery may be necessary. The procedure is typically performed by a consultant orthodontist in collaboration with an oral and maxillofacial surgeon.
Underbite surgery is a common treatment for correcting significant misalignments. If you have concerns about the outcome, you can request to see before-and-after photos of previous patients who have undergone similar procedures.
Before surgery, your orthodontist will fit braces to realign your teeth. Although this may temporarily worsen your bite, full correction will be achieved after surgery.
The surgery, performed under general anaesthesia, involves repositioning either the upper jaw, lower jaw, or both. Small screws and titanium plates are used to hold the bones in place during the healing process.
Expected benefits after surgery include:
There are no visible scars after surgery, as incisions are made inside the mouth. Elastics will be attached to your braces following the operation to maintain proper bite alignment as the bones heal. You will need to take at least four weeks off work or regular activities to allow for recovery.
| Treatment Option | Permanent, Long-term or Removable | Treatment Duration | Suitable Treatment Age |
|---|---|---|---|
| Upper jaw expander | Removable and fixed appliances | 6 to 12 months | Before 13 years |
| Reverse pull face headgear | Removable | 6 months | Before 10 years |
| Chin cap | Removable | 6 months | Before 10 years |
| Underbite braces like Invisalign | Invisalign is removable; traditional braces are fixed | 1 to 3 years | When most adult teeth have erupted |
| Tooth extraction | Permanent | Single dental visit | When all adult teeth have emerged |
| Underbite surgery | Permanent | 1 to 3 years | Above 18 years |
Babies born with a cleft lip and palate are at a high risk of developing an underbite due to improper development of the upper jawbone and teeth. Individuals with an underbite and cleft lip generally need to undergo surgery to address these issues. A team of specialists will correct the complications over time, using braces and surgical procedures if necessary. Children with cleft lip and palate receive multidisciplinary care from orthodontists who specialise in managing these conditions.
Routine dental visits are essential for maintaining proper oral health, including the alignment of your bite. Misaligned teeth can make you more susceptible to infections and painful symptoms, similar to those associated with TMJ disorders. If you are an adult with an underbite, it’s advisable to consult your dentist to determine if treatment is necessary. As a parent or caregiver, it’s important to schedule a dental visit for your child within their first year of life and ensure regular check-ups. By identifying and treating misalignment early, your child will be less likely to experience underbite-related symptoms in the future.