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Crooked Teeth and Genetics

Updated on: July 21, 2021
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Approximately 4 million people in the United States wear braces, clear aligners, or other dental corrective devices. This is according to the American Association of Orthodontists.

Crooked teeth, or misaligned teeth, are a problem that has existed for many, many years. Long ago, corrective measures for straightening teeth were ancient and painful. Jutting teeth were filed, and overcrowded teeth were forced apart through metal forceps. With the advancement of technology, treatments for misaligned teeth have evolved into what they are today.

It is said that our ancestors used to have straight teeth. Anthropologists say that changes in the diet caused the human jaw to shrink. This is brought about by food that requires less chewing.  

However, genetic studies revealed that the genes we inherit from our parents are responsible for our jaw size, dental arch, and our number of teeth.

Are crooked teeth genetic?

Genetics plays a major role in the development of crooked teeth. If your parents have misaligned teeth, there’s a very high chance of you having misaligned teeth, too.

Some genetics-related factors that cause crooked teeth in children include:

  • Abnormally large teeth
  • Having extra teeth
  • Misaligned jaws
  • Overbites
  • Underbites

But while genetics cause crooked teeth, other factors influence teeth alignment. Assess your genetic predisposition, so you are aware of your risk. If you are genetically inclined to develop crooked teeth, improve your dental health through proper oral hygiene. This will reduce your risk for other oral health problems.

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Causes of crooked teeth

Aside from the influence of genetics, certain environmental factors lead to crooked teeth, too. Some habits and disorders cause crowded teeth and undeveloped jaws. These include:

Mouth breathing

Mouth breathing happens because of asthma, allergies, and other conditions that force a person to breathe through the mouth. This puts the tongue in an abnormal position. Uncorrected, prolonged mouth breathing leads to an undeveloped upper and lower jaw. 

Open mouth posture

Similar to mouth breathing, an open mouth posture places the tongue in an abnormal position. This would eventually cause teeth misalignment because of undeveloped jaws.

Prolonged use of pacifiers and thumb sucking

In babies and very young children, pacifier use or thumb sucking are normal habits during the developmental stage. This is according to the Institute for Quality and Efficiency in Healthcare. However, thumb sucking or pacifier use should stop when the child is 3 years old. Prolonged thumb or pacifier sucking can lead to crooked teeth.

Tongue ties

A tongue-tie, otherwise known as ankyloglossia, is a condition where babies have very limited tongue movement. This happens because the frenulum happens to be too short or too tight. The frenulum is that piece of tissue that anchors the underside of the tongue to the bottom of the mouth.

Limited tongue movement forces the tongue to assume an abnormal posture which narrows the palate. This results in very little space for teeth to grow properly.

A baby with an untreated tongue-tie will, later on, have problems like periodontal disease (or gum disease), tooth decay, and teeth misalignment when permanent teeth develop.

Tongue thrusting 

Also known as reverse swallowing, tongue thrusting happens when the lips push back, and the tongue pushes forward during the act of swallowing. When this happens, the tongue is thrust forward against the baby teeth. Over time, this can lead to an open bite.

Tooth loss

A tooth falling out causes the remaining teeth to move to fill the vacant space. Teeth movement will eventually cause crooked teeth. Seek professional intervention when you lose a tooth so that they can provide medical advice and prevent misalignment.


Trauma can lead to the loss of a tooth. This may come in the form of physical violence, an accident, or sports injuries. These can alter jaw shape and cause teeth movement. In adults, contact sports is one of the most common causes of crooked teeth.

Tumors of the mouth and jaw 

Some forms of oral cancer cause the formation of tumors. Tumors found in the mouth and jaw causes crooked teeth. The space occupied by a tumor forces the teeth to move, which leads to misalignment problems.

Types of crooked teeth

Crooked teeth come in different forms, shapes, and sizes. However, there are three recognized classes of malocclusions. These include:

Class 1 malocclusion

Among the different crooked teeth, this is the most common type. This happens when the upper teeth slightly overlap the lower teeth. Despite the overlap, the bite remains normal.

Class 2 malocclusion

A class 2 malocclusion happens when the upper jaw and upper teeth severely overlap the lower teeth and lower jaw. This condition is called an overbite and can cause painful chewing. Headaches and temporomandibular joint dysfunction (TMD) are associated with an overbite.

Class 3 malocclusion

In a class 3 malocclusion, the lower teeth jut out beyond the front of the upper teeth when the jaw is closed. This is also referred to as an underbite

People with underbites often encounter chewing problems. They also experience frequent headaches. When left untreated, underbites can cause Temporomandibular Joint Disorders (TMD).

Problems associated with crooked teeth

While having crooked teeth is a problem in itself, there are also other problems associated with it. 

Crooked teeth cause difficulty in chewing. The jaw is strained, which increases the likelihood of you breaking a tooth. Additionally, crooked teeth are hard to clean. This predisposes you to develop dental caries. There could also be enamel-related problems because protruding teeth rub against other teeth and wear down the enamel. Thinner enamel generally weakens the tooth.

More than this, crooked teeth have a major impact on a person’s overall health and well-being. Misaligned teeth increase the chance of bacteria hiding into gum pockets which can cause gum disease. Studies say that untreated bacteria in the teeth can go into the bloodstream and may cause life-threatening conditions such as stroke, diabetes, and heart disease.

What to do with crooked teeth

Having crooked teeth is not a reason to be disheartened. There are dental treatments available that can significantly improve the function, stability, and appearance of crooked teeth. With the latest advancement in dental procedures, you’ll have a beautiful smile in no time.

Metal braces, or traditional braces, have been used for a long time. However, most people nowadays opt for something less noticeable than the standard metal brackets. You can now opt for dental veneers, clear plastic aligners, and dental bonding. Talk to an orthodontist and discuss what will best work for you. 

Aside from these, good oral hygiene is very important. As your dentist will tell you, brush using fluoridated toothpaste twice a day, floss, and get regular dental checkups.

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