If you have crooked teeth or a misaligned jaw, your dentist or orthodontist may have told you that you have a malocclusion. A malocclusion isn’t a one-type condition, and it can be mild or severe, sometimes needing surgery.
It’s important to understand the types of malocclusion, their causes, and how they can be treated. We are detailing everything there is to know about malocclusions, including how it can affect you and when to see a doctor.
A malocclusion is where the upper and lower teeth do not meet correctly. Sometimes, the upper or lower jaw protrudes in front of the other, or the teeth may be crooked or crowded.
Severe malocclusion typically causes difficulty eating, speaking or closing your mouth correctly.
Diagnosis and treatment planning requires dental examination and X-rays.
Braces, surgery, or a combination of treatments are required to correct malocclusions.
Malocclusion may be genetic where abnormalities in bone development are involved; oral habits and sinus problems are also common causes.
The definition of malocclusion is simply “bad bite”. It is a condition where your upper and lower teeth do not meet correctly due to excessive overlap, or one or more teeth cannot touch because of a gap. A malocclusion may be dental, where only the teeth are involved, or skeletal, where your jaw and facial structure affect your bite.
Malocclusion is pronounced as mal-ah-clue-zhun; breaking it up into syllables, you get mal-oc-clu-sion.
“Mal” means “bad”, and “occlusion” refers to the closed state of your mouth at rest or when biting.
Here are some examples of the different types of malocclusion:
A Class 1 malocclusion is the most common type, where your upper teeth slightly overlap your lower teeth, but your bite is normal. It is often the least detrimental to your health and quality of life [1].
In general, your molars are aligned in a relatively normal position, but your other teeth may be spaced too far apart, or you could have crooked teeth, crossbite, or overcrowding.
The global prevalence of class I malocclusion ranges between 34.9% to 93.6%
A Class 2 malocclusion is also known as an overbite. Here, your upper teeth overlap your lower teeth. You may have trouble eating or speaking clearly in this case, particularly if the bone structure is involved.
Skeletal involvement of a Class II malocclusion can feature a smaller lower jaw, typically, giving you a heart-shaped face with a small chin.
The facial structure seen in overbite involves a smaller angle between your lower jaw and teeth too because they are positioned underneath your upper front teeth. You also have a wider angle between your upper teeth and eyes [2].
If you’re struggling with figuring out how to fix an overbite, click here.
Class 3 malocclusions, also known as an underbite, are less common, occurring in less than 5% of the U.S. population [3]. Here, your lower teeth sit forward and overlap your upper teeth. Your lower jaw is positioned forward in more severe cases. It is essentially the opposite of an overbite.
When there is skeletal involvement in Class III malocclusions, your lower jaw may be larger, creating a “square” or “rectangular” facial shape.
Have you been diagnosed with Class III malocclusion? Learn how to fix underbite here.
Class III malocclusion showed to be more common in Asia, with 6.46% of the population affected
Left untreated, malocclusion can have several negative effects on your oral health and quality of life:
Malocclusions are caused by:
Lifestyle factors mainly have an influence during early childhood, when the upper and lower jaws are still developing.
You or your child may have gene variations that affect the development of the jaw and teeth, and this can manifest as a malocclusion. Congenital defects appear during fetal development, and they are typically difficult to predict or prevent. Mouth breathing may reveal a congenital issue with skull growth [3].
However, genes only account for 40% of the risk of malocclusion and have greater involvement in skeletal deformities [5].
Neuromuscular conditions such as muscular dystrophy can increase the risk of malocclusion, as dysregulated muscle tone and poor strength place incorrect or insufficient stress on the teeth and jaw bones.
Thumb sucking and other types of non-nutritive sucking (e.g. pacifiers, toys, and fingers) can increase the risk of open bite, crossbite and overbite. The sucking motion causes the muscles in your mouth to move in unhealthy patterns, slowly shifting your teeth up and outwards, or causing them to lean back towards your tongue.
Besides thumb sucking, mouth breathing and tongue thrusting can also put a strain on your mouth and jaw muscles. Mouth breathing can be a consequence of sinus problems, so these must be treated to see long-term success.
Tongue thrusting is an intermittent or constant forward motion of your tongue, which you may have as a habit because of jaw issues. It is usually too intermittent to have a significant effect on teeth alignment. However, if your tongue is positioned forward for most or all of the time, it can cause irregular teeth alignment as constant light pressure has more of an effect.
Studies estimate that over 10% of children continue non-nutritive sucking past the age of five, but usually, they replace thumbs and pacifiers with more socially acceptable objects such as a pencil, piece of jewelry, or their finger. Not only can this contribute to poor oral hygiene, but it impairs upper jaw development and prevents adult teeth from moving to the correct position [6].
Besides non-nutritive sucking, other health and lifestyle factors including diet and allergies can increase the risk of malocclusion:
Depending on the severity of your malocclusion, symptoms can include:
A malocclusion is typically diagnosed during routine dental examinations. If your dentist suspects issues with bone development, dental X-rays will likely follow to get a clearer picture of your teeth and jaw alignment.
You should see a doctor if your dentist is unable to treat you on their own. Early treatment is important in order to prevent dental diseases such as tooth decay and gum disease, which are more common in malocclusion. Additionally, prevention of nerve or joint damage is essential to avoid chronic pain or other disability.
It is also best to see a doctor if you have chronic pain as a result of your malocclusion, or you have difficulty eating, which can lead to malnutrition, or experience a significant speech impairment.
If your malocclusion is severe enough to require treatment, there are several options:
Orthodontic treatments are known as camouflaging interventions. Both dental braces and lingual braces work by correcting misaligned teeth. However, they do not affect any underlying bone structure issues. For this reason, orthodontic treatment is only a stand-alone intervention for mild malocclusion, but not every case is seen as severe enough for treatment [4].
If you have a milder case of misaligned teeth, teeth aligners may be a more appealing option. These are clear plastic appliances that gradually shift your upper and lower teeth into the correct position without uncomfortable metal wires and brackets. However, aligners are not always suitable for severe malocclusion [9].
The advantage of teeth aligners is that you can remove them to eat and brush your teeth, and you don’t have to worry about irritation or injury to your cheek. This helps to reduce your risk of tooth decay compared to traditional braces, as there are no brackets and wires to work around [10].
Read more on clear aligners such as Invisalign for overbite, here.
| Byte clear aligners can correct mild to moderate misalignments in 2-4 months |
Jaw surgery is a necessary malocclusion treatment when there are underlying issues with bone development.
For example, the surgery used to treat severe overbite is called a mandibular osteotomy. Here, your surgeon cuts behind the teeth of your lower jaw, in order to avoid every tooth socket. Then, your jaw is pulled forward, and titanium plates or screws are used to keep it in the new position [11].
Besides orthognathic surgery, you may need sinus surgery to prevent the need for mouth breathing [12]. This is why careful treatment planning is essential before getting started, to avoid unnecessary procedures. Surgical reshaping takes several months to recover from, as it essentially involves deliberate jaw fractures.
If you have issues with a crowded mouth, extraction may be necessary if your teeth cannot be straightened. The nearby teeth can then move into a straighter position, but you will likely need braces to ensure they are properly aligned.
Learn more about overbite surgery here.
Surgery and orthodontic treatment are commonly used together in treating malocclusion. You may wear braces for several months leading up to surgery, in order to begin moving your teeth into the properly aligned position.
For example, in a case study of a man who initially saw successful treatment of his malocclusion, but then suffered a relapse, a combination of surgery, braces, and habit correction was necessary [12].
If you have a family history of malocclusion, it is likely that the issue is genetic for you.
There are ways you can reduce the risk of your child developing malocclusion, like discouraging thumb sucking from an early age, as well as sucking other objects such as pacifiers and toys [6].
Malocclusions don’t usually develop later in life as your skull and jaw bone have already finished growing, and your permanent teeth have erupted and moved into place. Except for injuries such as certain jaw fractures, you are very unlikely to develop a malocclusion as an adult.
In summary, what are malocclusions, and how are they fixed?
Malocclusion can range from barely noticeable to debilitating, but many cases are preventable in childhood. Healthy oral habits such as hygiene and avoiding sucking objects; getting proper nutrition, particularly fat-soluble vitamins; and treating conditions that affect breathing can go a long way in preventing issues with malocclusion.
The different types of malocclusion are treatable with orthodontic interventions and surgeries. However, even if you have been successfully treated, correct breathing and oral habits are essential to prevent relapse.
