An underbite occurs when the lower teeth sit further forward than the upper teeth. This condition is often genetic, and underbite correction is usually recommended to avoid problems later in life.
It is possible to fix an underbite; surgery and braces are common options, along with some other treatments. Here, we’ll talk you through everything that you need to know about this type of dental malocclusion and how it may affect you or your child.
Table of contents
- 1 What is an underbite?
- 2 Do I need underbite correction?
- 3 How to fix an underbite
- 4 Underbite and cleft palate and lip
- 5 Underbite correction on the NHS
- 6 Underbite teeth: Conclusion
What is an underbite?
An underbite occurs when the lower jaw sits further forward than the upper jaw, causing the bottom front teeth to stick out. This condition occurs in around 5-10% of the population.
In lots of people an underbite jaw is barely noticeable, with the bottom teeth resting just slightly in front of the top teeth. In more severe cases, there can be a very noticeable gap between the sets of teeth. No matter the severity of the bite misalignment, underbite correction is generally recommended because of the problems it can lead to if untreated.
What causes an underbite?
Most cases of underbite teeth are genetic; if at least one parent has (or had) an underbite then the chances of their children having an underbite increases. The condition is also linked to cleft lips and palates. It may also result from certain childhood behaviours such as:
- Thumb sucking
- Tongue thrusting
- Overuse of a dummy
- Bottle feeding for too long
It may be that the upper jaw is to short and hasn't developed properly or the lower jaw protrudes too far – or a combination of the two.
Do I need underbite correction?
One of the big differences between an underbite and overbite is that some small overbite is natural, whereas no kind of underbite is considered ‘normal’. There are lots of problems that come along with having underbite teeth, and the longer you wait to correct them the harder the treatment may be.
If your child or baby has an underbite, it is best to start treatment early, when their bones are more easily moved. Without treatment, there are lots of potential problems your child could face, including:
- Problems with biting and chewing food properly
- Speech issues such as slurring and lisping
- Facial pain because of abnormal strain or pressure on the jaw
- Increased chances of tooth decay
- Worn down and cracked teeth
- A differently shaped face than normal
Here, Dr Chang talks through the problems that children can experience with underbite teeth, and why early intervention is important:
How to fix an underbite
If you, your child or your baby are diagnosed with an underbite, of course you'll want to know how to treat it. There are a number of ways that have been developed to successfully fix an underbite. Your dentist will explain the best approach for your situation, but below you can find an overview of the most common treatments.
Usually, two or more of these treatments will be combined to provide the most effective, long-term solution for you, your child, or your baby with an underbite.
Upper jaw expander
In cases where an underbite jaw is caused by the upper jaw not developing fully, a jaw expander helps it develop to the correct shape. This is a metal device that fits over the back teeth. It gradually pushes out the teeth and expands the palate. Some devices are removable, like a retainer, while others are fixed in place.
This is one of the least noticeable forms of underbite correction; unless you laugh or yawn, nobody is likely to see the top of your mouth or back teeth where it sits. People who have used a jaw or palate expander say that it can be painful, but some discomfort is expected when you are manipulating the jaw bone. Since jaw bones don’t fuse until around age 12 or 13, starting this treatment at a young age will make things a little bit easier.
A jaw expander is normally used for around one year, but it depends on how much teeth movement is required. Once the treatment is complete, patients have to wear a retainer for a while so that new bone can grow, making the overbite correction permanent.
Reverse pull headgear
Another method of underbite correction is a reverse pull face mask or headgear. This sounds quite scary, but is it a normal way to fix an underbite. The headgear rests on the forehead and chin and attaches to braces or a retainer using elastic bands to pull the upper jaw slowly into position.
This short animation shows how reverse pull headgear can be used in conjunction with a jaw expander to correct an underbite:
A study has shown this method of underbite correction to be up to 75% effective overall, even more so if treatment is started before the age of ten.
To get the most benefit, the reverse pull headgear should be worn as often as possible; certainly every night, and perhaps even during the day. Your child may not mind wearing it while watching TV or doing homework, but wearing it to school and social events is another matter. Still, you should follow your orthodontist’s advice, because using a reverse pull face mask could reduce the need for underbite surgery later on.
Chin cap or cup
A chin cap, or cup, works in a slightly different way. This device fits over the head, from the crown to the chin, and is designed to reduce the growth of the lower jaw by pulling it back during the years of bone growth in a child.
This method is normally used at the same time as a reverse pull face mask, so as the upper jaw is moved into a better position the lower jaw underbite doesn’t get any worse. The chin cap needs to be worn during sleep and at times where it wouldn’t cause embarrassment, like when your child is hanging out at home.
Along with the methods mentioned above, braces are normally part of underbite treatment. As with braces for other problems, such as overbite, crossbite and open bite, underbite braces will twist, push, and move your teeth into a better alignment.
If you or your child are treated as an NHS patient, only metal braces will be offered. As a private patient, however, you will have the option of other, less noticeable options such as clear braces (pictured).
After you have completed your treatment for underbite correction with braces, you will need to wear a retainer to maintain the progress you have made.
Invisalign for underbite correction
It's also possible to use Invisalign for an underbite in many cases. These clear aligner braces are almost invisible, making them a popular option for people who don't want it to be obvious that they are wearing braces.
It may be possible to treat an underbite with Invisalign braces alone, or they might be incorporated into a course of treatment that includes underbite surgery too.
To check whether you or your child are a suitable candidate for Invisalign underbite correction, take a free Smile Assessment today. It just takes a couple of minutes to get your results and connect with a dentist in your area.
Alternatively you can book an appointment online with an Invisalign dentist near you.
Sometimes, an underbite can be caused by having too many teeth in the lower jaw. If this is the case, your dentist will likely advise you have some teeth removed. Extraction may also be necessary to help braces work effectively, as it frees up space for the rest of the teeth to move into.
Tooth extraction is normally done under local anaesthetic, although general anaesthetic may be used for complicated or multiple extractions. This is a common process which is usually quick, simple and pain-free. The dentist just pushes or twists the tooth to loosen it in the socket, then takes it out. You can read more about the extraction process here.
Underbite jaw surgery
Sometimes the problems with an underbite jaw are quite severe and will require surgery. Underbite jaw surgery can involve a few different things, depending on where the surgeon identifies the problem.
The lower jaw might need to be pushed back and repositioned, or the underbite surgery might focus on the upper jaw. Either way, there will small screws and plates inserted around the bones to make sure that they don’t move back. Occasionally, both jaws will need adjustment.
Your surgeon will talk you through what the difference will be in your underbite before and after the surgery. Some common changes include:
- Improved speech
- A different face shape
- Better dental hygiene
This type of surgery isn’t uncommon and you can ask your surgeon or dentist to show you underbite surgery before and after pictures if you are worried about the changes in appearance.
There aren't normally any scars from underbite surgery because all of the cuts are made inside the mouth. The jaws may be wired following the surgery, or an internal frame placed in the mouth, to make sure the bones heal in the correct position.
Patients are recommended to take 2-4 weeks off school or work after underbite jaw surgery. Treatment usually involves the use of braces before or after surgery, or both.
Underbite treatment summary
Here is a brief overview of the different types of treatment you may be offered for underbite correction:
Underbite and cleft palate and lip
There is greater likelihood that babies born with a cleft palate or cleft lip will also have an underbite. It is common for the upper jaw bone to not develop properly in a cleft palate or lip case, causing an underbite to occur.
Generally, underbite surgery is needed to correct the problem and is unlikely to be much different to the surgery outlined above. Some surgery to fix issues with the cleft may be done at the same time, or it many be carried out separately. Your NHS Cleft Team will walk you through the treatment, and you can seek support from CLAPA too.
Underbite correction on the NHS
Underbite surgery costs nothing through the NHS for children under 18 years old, while for adults the band 3 treatment charge of £269.30 applies. The NHS only covers dental surgery and orthodontic work for adults when deemed medically necessary, which it often is in the case of an underbite.
In any case, your dentist will be able to tell you if you are eligible for NHS treatment. As an adult, NHS underbite surgery costs will cover everything required to treat the condition, including any braces you wear for your underbite before and after your operation.
Underbite teeth: Conclusion
Underbites are a lot less common than overbites; only about 5-10% of people will experience this condition, and it really should be treated in every case. The range of possible ways to fix an underbite means there will be a method that suits you or your child.
When a baby has an underbite diagnosed, a treatment plan can be put into place to ensure the least invasive correction technique is used. The success rates of treatment when done early are really high, and even if surgery is needed, it will make a big difference to your child's oral health and overall wellbeing in the years to come.
Remember that underbite correction with braces needn't involve conspicuous metal brackets and wires. Removable clear aligner braces are a popular choice because of their appearance and convenience. See if you're a suitable candidate for invisible braces by taking Invisalign's two-minute Smile Assessment today or visiting your nearest Invisalign dentist.