What is a crossbite?
You may have crooked teeth or a crooked smile, but these are broad terms that could refer to many underlying causes of misaligned teeth or jaws. These misalignments are called malocclusions.
One type of malocclusion is a crossbite, which is a misalignment of the upper and lower teeth so that one set covers the outside of the other when they meet. This alignment problem can occur because the upper jaw is larger than the lower jaw, or vice versa.
Crossbites at the back of the mouth cause teeth grinding, jaw problems and pain, abnormal facial development, and wear on the teeth. This can lead to decay, tooth damage, and gum disease.
Crossbites often become apparent as a child loses their baby teeth, and their permanent teeth start to come in. This is a period called mixed dentition because not all the permanent teeth have come in.
Dentists try to catch this misalignment early in life because crossbites are simpler to manage and adjust in adolescents and teens than in adults. However, there are still options for adults who have an uncorrected crossbite. Treatment methods range from aligners or braces to surgery.
How is a crossbite diagnosed by your dentist?
In an average, healthy bite with proper alignment, the upper teeth will sit just a little outside of the lower teeth. This is true with the front and back teeth, on all sides of the mouth. When the teeth do not meet correctly in one or more of these dimensions, you have a crossbite.
The American Association of Orthodontists (AAO) defines a crossbite as the abnormal relationship of a tooth or a few teeth to their opposing teeth.
There are two basic types of crossbite.
This is where the top front teeth sit behind the lower front teeth. This may give the appearance of an underbite, where the jaw juts out. Unlike a traditional underbite, an anterior crossbite has more to do with alignment of teeth than the jaw.
This occurs when the back teeth on top bite down inside the back teeth on bottom, instead of being slightly outside. About 1 to 16 percent of children develop this bite before their permanent teeth erupt. It is important for paediatric dentists to monitor this crossbite and see how adult teeth might align in relation.
Even though these types of crossbite may not be very visible, they can impact your oral health. When they are uncorrected in children, the face may grow asymmetrically. Misaligned teeth may mean that you clench your jaw more, or your enamel gets worn down faster because your teeth are at unhealthy angles.
You could have headaches and neckaches from jaw clenching. You may be more likely to get gum disease and cavities because of worn enamel or food particles getting stuck in places that are harder to clean. Your jaw may grow to one side or shift as you get older, which can impact the muscles and tendons around your head.
In 2020, the most effective crossbite treatments are braces, aligners, and surgery, while the best treatment for you will depend on the severity of your crossbite.
Do crossbites ever correct on their own?
While there are instances in which a childhood crossbite corrects itself later in life, this is rare. Some studies suggest that up to 9 percent of crossbites self-correct, but that is the highest estimate.
While many children receive treatment for crossbites at a young age, adults can develop crossbites due to genetics, poor hygiene, health, or diet. Even if you had braces as a child, you may need a bite adjustment later in life.
Treatments for crossbite.
For cases of crossbite, your orthodontist may recommend other orthodontic appliances.
Palatal or Maxillary Expander
This is a device that attaches to the upper teeth and expands the palate gradually, using a special key on the device. Since children’s palates are still growing, it is most effective to use this device at a younger age; however, sometimes adults still receive them.
This is a device that adults wear at night to widen the upper palate when only minimal expansion is needed.
Surgically Assisted Palatal Expansion
A surgeon breaks the jawbone in several places. Afterward, the customer wears a custom-made device. This is a more intensive procedure, reserved for people who need even more expansion than basic expanders can provide over time.
Worn on the head and face, headgear attaches to the teeth with wires. It helps to adjust both the teeth and the jaw. It also slows the growth of the jaws, so it can be an effective treatment in children and teenagers, but it is less likely to be used on adults.
If needed, your dentist may recommend additional treatments like:
- Tooth removal to give crowded teeth more room.
- Capping and bonding dental restorations to improve teeth that may hit each other in uncomfortable ways.
Since crossbites involve palate sizing problems along with tooth crowding, you will probably get braces or aligners after your palate is adjusted.
At-home aligners may help crossbites.
Many adults remember having “metal mouth” as kids and do not want braces again. As a result, they avoid orthodontic treatment, thinking braces are the only option to correct their bite. Fortunately, there are options available that are much less intrusive than traditional braces or other devices.
Depending on the severity of your crossbite, you may be able to use aligners to correct your smile, and they are much subtler than braces. Clear aligners slip over the teeth, and they are often difficult to see unless someone is very close to you. If you have an important meeting or engagement, you can remove the aligners for short periods of time.
Though research is still nascent, there is some evidence that modified aligners are a good option for crossbite treatment. One study found that customers who wore their aligners for the recommended amount of time experienced good results. Adherence to the treatment plan was crucial, requiring that customers wore the aligners for the recommended amount of time each day.
Specifically, Invisalign can be a good option for some cases of crossbite. Your dentist or orthodontist can evaluate your case and help you with your decision.
A doctor can monitor your entire treatment regime, ensuring that your teeth are moving as intended. At the end of your treatment schedule, your crossbite can be corrected.
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Correction of Anterior Crossbite Using Modified Transparent Aligners: An Esthetic Approach. (July-September 2016). Contemporary Clinical Dentistry.
Crossbite: Effects and Treatments. Colgate.