An open bite is a type of malocclusion that causes a gap between the lower and upper teeth—it’s a condition that affects many, and is not always easy to treat depending on its severity.
We’re taking you through everything there is to know about open bite malocclusions; the different types, causes, and possible treatment options.
Anterior open bite occurs when your incisors do not meet, while posterior open bites feature a gap between one or more molars.
Many children eventually grow out of the condition as their baby teeth are replaced by adult teeth and their jaws mature.
Some open bites have no other symptoms than their appearance, others involve difficulty with chewing or speaking.
Treatment may involve braces or aligners; surgery and behavior modification.
Oral habits, such as consistent thumb sucking, are often the culprit of dental open bites, while skeletal open bites are caused by genetics.
An open bite malocclusion is a condition of misaligned teeth, where the anterior teeth or posterior teeth do not touch in the front or back of the mouth when the jaw is shut. This type of malocclusion affects roughly 0.6% of Americans, including 16% of African-American children and 4% of white children .
Open bite is most prevalent in Asia with 7.79% affected. In America, only 3.09% have open bite
Open bite can persist into adulthood, which is not unusual among orthodontic conditions. The CDC estimates that the average American adult will spend close to two hours in an orthodontist’s office as a patient every year.
There are different types of open bites, which fall into the following categories:
A posterior open bite occurs when the molars and premolars don’t touch when biting down. This can lead to facial asymmetry and temporomandibular joint disorder (also known as TMJ).
The posterior form is less common and more difficult to treat.
An anterior open bite affects your front teeth, making it the more visible type. Anterior open bites mostly involve a gap between your incisors and canines, but your molars may fit together normally.
While a skeletal open bite is caused by genetics resulting in malformation of the jaw or skull (or both), dental open bites are simply issues with the formation and placement of the teeth .
Open bites can involve the front teeth or back teeth, and originate from the bone structure or tooth alignment.
The main symptom of an open bite is a gap between your upper and lower teeth. Some individuals have no other symptoms, particularly if there is only a slight open bite.
In more severe cases, there may be mouth breathing, chronic jaw pain, abnormal speech and swallowing, trouble chewing, and tongue thrusting. Children with open bites often stick to soft foods past the usual age, as eating chewy or crunchy food is too difficult .
An open bite can be caused by the following:
Temporomandibular joint disorders and ankylosis, where fusion to the bone prevents permanent teeth from erupting, are two other causes that can be involved in a posterior open bite.
Additionally, rare disorders such as Duchenne muscular dystrophy may lead to posterior open bite through poor muscle strength and tone .
Facial morphology—what your face looks like, including the upper and lower jaws—is largely controlled by genetics. In the case of open bite, a longer facial structure is implicated, where there is more vertical growth or less horizontal growth. An anterior open bite may involve more vertical growth in the molar area or less eruption of the front teeth .
Sometimes, posterior open bite occurs in familial clusters, pointing to a stronger genetic effect than for anterior open bite. Genes that are linked to teeth alignment issues include those that affect bone development, muscle function, and growth hormones .
The major habitual cause of open bite is thumb sucking and other types of non-nutritive sucking (NNS). Research estimates that 10-15% of children practice this into their school years, often replacing the thumb with a less conspicuous alternative, such as a finger or object. Over time, this constricts upper jaw growth and shifts the positioning of the newly-erupted adult teeth .
Finger sucking showed to be the most significant risk factor for AOB, followed by pacifier use and nail biting
Tongue thrust was thought to be another oral habit that led to open bite, but the intermittent nature of this habit may not be enough to shift tooth positioning forward. Constant forward positioning of the tongue, whether or not tongue thrusting is at play, is more likely a cause as teeth respond to continual light pressure.
An open bite can be caused by genetics, including bone structure and muscular disorders, as well as habits such as thumb sucking.
There are several ways to fix an open bite, depending on the cause and severity:
Traditional braces are a common treatment for dental open bite, where permanent teeth have not straightened out.
Headgear and other add-ons may be used when necessary, such as bite blocks to suppress excess eruption of your back teeth. Braces may be helpful but won’t serve as a complete treatment on their own if skeletal issues or bad habits are at play .
Clear aligners may be better types of braces, as they are more comfortable, convenient, and attractive. These can be effective for mild to moderate cases of open bite and other malocclusions, but technology is improving to enhance their efficacy in more situations and degrees of severity .
You can even purchase at-home aligners, such as Byte and AlignerCo. Simply make a mold of your teeth using the impression kit; a team of professionals will then put together your treatment plan.
Some at-home aligner companies offer lifetime support, providing you with complimentary retainers to maintain your new smile.
Keep in mind, the American Dental Association does not currently endorse at-home aligners. Telehealth also does not enable treatment for oral health issues such as cavities, missing teeth, fractured teeth, habit correction or problems that require jaw surgery.
To learn more, read the full Byte aligners review here, or check out the AlignerCo review to compare.
Open bite procedures usually involve orthognathic surgery, where the jaw is corrected.
Surgical intervention is useful in more severe cases of skeletal open bite, for instance, maxillary osteotomy, where the upper jaw is cut to have its alignment changed, lengthened or shortened. Tooth extraction may also play a role in treatment .
Sinus surgeries, such as otorhinolaryngological intervention, might be an option if difficulty breathing is the cause of poor oral health and habits.
In a case study where a man presented with a relapse of his anterior open bite, sinus surgery was required to help him breathe easier. This in turn improved the incorrect tongue posture that pushed his front teeth forward .
Relapse of open bite occurs in some cases when oral habits aren’t corrected. A tongue crib or tongue spurs can be used in adults to retrain tongue posture .
In early childhood, treatment options can include wraps or bad-tasting sprays to prevent thumb and finger sucking, as well as habit training. Habit-breaking appliances, such as tongue cribs, are common at an early age before permanent dentition to prevent tongue thrusting and thumb sucking.
Treatment for open bites generally involves a combination of braces and behavior modification. Surgery might be needed in some cases.
With the right treatment, you may correct your open bite in one to two years. Treatment time depends on the severity of your open bite as well as the methods used.
Whether or not you need an open bite correction depends on its level of severity. Many adult patients only complain of their appearance, so it is not “necessary” for health reasons.
Open bite treatments among children are not always necessary either. During the mixed dentition phase, where baby teeth and permanent teeth are present, malocclusions are common. The gaps left by fallen baby teeth, and the mismatched size between them and permanent teeth, can lead to temporary misalignments.
What are the most important things we need to know about an open bite?
Open bite malocclusion has not been assigned a numbered class but can develop alongside other types, such as Class I (crowded teeth or crooked teeth).
Successful treatment of posterior open bite is possible, even in largely genetic cases where it runs in the family. However, relapse can happen, so continued monitoring and support may be required .
In the case of an anterior open bite, simply look in the mirror. There will be a vertical gap between the two rows of teeth, with the front teeth likely pushed forward to create the gap.
You may be able to feel for a posterior open bite by running your finger and tongue along your molars, which can reveal a gap between each row.
Not every case is serious, as there are different degrees of severity. Some are so mild that they may cause no other symptoms than their appearance. More serious cases can lead to difficulty speaking or eating.
An open bite may make you feel insecure, but there is hope for successful treatment well into adulthood. Options ranging from aligners to surgery are available depending on your level of severity, with mouth and tongue habit training often a necessary add-on.