Causes of Teeth Malocclusion

The main causes of dental malocclusion are described below:

• Hereditary causes related with the development of jaws and teeth
• Tooth loss related with non hereditary factors such as diseases or trauma
• Oral habits that affect the teeth and jaws health

A general cause of malocclusion is teeth that have too much or too little room in the jaw.

• Size & shape of teeth & jaws - The size, shape and structure of our jaw bones and teeth are controlled from our genes. If a family has a history of large teeth, it is very likely that new members will have them also. These genetic factors may result in large or small teeth in a normal mouth, or normal teeth in a small or a large jaw. Any asymmetry between teeth and jaws can cause malocclusion and lead to orthodontic problems. Large teeth in a small jaw will get crowded, while small teeth in a larger jaw will drift out of place causing spacing problems. In other cases, genetic prevalence may result in missing teeth or teeth that erupt in one another's place (transposed teeth). More rarely, people are born with conditions that can create malocclusion problems, such as a cleft palate.
• Evolution - a theory is trying to explain orthodontic problems in modern humans based on the hypothesis that Homo Sapiens have evolved smaller jaws without a reduction in the number of teeth happening at the same time.
• Growth pattern - even if a person’s teeth and jaws are going to be normal sized when fully developed, an uneven growth pattern of the jaws during permanent teeth eruption usually leads to malocclusion.

The following conditions result in excess space for teeth and lead to spacing problems:

• Missing teeth - some children are born lacking one or two teeth in their jawbones, or they do not develop and erupt properly.
• Small teeth - some children may have small teeth that cause diastema (gapped teeth).
• Large jaws - some children’s jaws are relatively large compared to their tooth size.

The following conditions result in less space for teeth than what is needed and lead to crowding problems:

• Extra Teeth - Sometimes, a person can have extra teeth. These teeth will usually erupt in strange positions and angles, or they will be trapped in the bone between erupted teeth and will not erupt.
• Small jaws - A small jaw can result in a limited amount of space for the teeth to grow. As with extra teeth, permanent teeth do not have enough space to erupt properly and cause teeth malocclusions.

Hereditary factors may also cause other teeth malocclusion problems such as crossbite, overbite and underbite:

• Different size of jaws – if the upper or lower jaw is larger than the other jaw, the person will likely have an overbite or underbite respectively.
• Misaligned Jaw and Bone Structure – A misaligned jaw or supporting bone structure will not only create malocclusion but it will also seriously affect the function of the mouth, leading to oral health conditions such as TMJ disorder (TMJD) and teeth grinding (bruxism).

Tooth loss may cause drifting of bordering teeth into the empty space, creating a bad bite. Common causes of tooth loss are:

• Trauma - if you lose a tooth due to a sports injury or an accident, then adjacent teeth may start to drift into the empty space. Wearing a dental mouthguard can significantly reduce the risk of teeth injuries.
• Dental Diseases – Tooth decay or gum disease may lead to the loss of one or more teeth; this often leaves a space where other teeth drift towards.
• Premature loss of primary teeth (baby / deciduous teeth) — Baby bottle tooth decay, a form of severe early childhood caries, that is common in kids who use to fall asleep with a bottle of sweetened liquid in the mouth, can cause the premature loss of several primary or even permanent teeth. If a primary tooth is lost too early, the permanent tooth loses its guide and can drift or erupt incorrectly.
• Malnutrition - nutritional deficiencies can alter the growth of the jaws and teeth.

Oral habits that place pressure on the teeth may slowly move the teeth out of place. The most common oral habits that cause malocclusion include:

• Thumb sucking - Although thumb sucking is a normal habit for babies, it causes serious orthodontic problems if it continues long after the eruption of permanent teeth. Prolonged thumb sucking can create crowded, crooked teeth, or bite problems. The child may also develop speech problems or problems with swallowing properly. Protrusion and displacement of front teeth are usual results of thumb sucking. Learn how to make kids to stop thumb sucking.
• Pacifiers – pacifiers cause similar problems like thumb sucking. Use of pacifiers as a substitute of finger sucking is not recommended.
• Lip-biting / Fingernail biting – both habits can shift the teeth out of alignment.
• Tongue Thrusting - Some children thrust their tongue forward, pressing it against the lips with a force that can result in teeth malocclusions such as ‘open bite’ or teeth protrusion (overjet).

While parents can not do much to prevent an orthodontic problem caused by hereditary factors, they can help their kids to avoid the need for braces, by maintaining good oral hygiene and avoiding bad oral habits that could cause teeth malocclusion problems.

Modern orthodontics are usually able to treat most teeth malocclusions successfully, but prevention can help the family to avoid the large cost of orthodontic treatment and the child will not have to wear dental braces and feel uncomfortable.

The cost involved with dental braces can be significant and many patients may not afford it if they are not covered by their dental insurance. Learn how to choose a dental insurance plan that will provide the best dental treatment to you and your family.