Crowded teeth or Crocked teeth is a term given to teeth when they are not aligned in their natural place in the jaw, because there is not enough space available for them.

Crowding is one of the most common orthodontic problems, as British statistics indicate that more than 60% of Caucasian children suffer from crowded teeth in one of its stages. While the statistics of the (Public Health Services Center in the USA) indicate that the incidence of crowding among white children between the ages of 6-11 years was 43.3%, and for those with darker skin, it reached 35.2%. This percentage increases with age, to become 87% for white children aged 12-17 years, and 84% for dark-skinned people of the same age group.
This increase was also associated with an increase in dental caries and premature loss of milk teeth. What supports the hypothesis of the influence of other factors - other than genetics – on this dental problem.
In fact, clinical observations lead us to the conclusion that the prevalence of crowding is constantly increasing, especially in modern societies.

We can relate this to several factors: 

•    the decrease in the jaw size -with the development of the human being over time-
•    the nature of food and its softness in modern societies
•    the early loss of the milk teeth, due to the increase in tooth decay in children which is related to the increase in consumption of sugars in our food.

We can divide crowding - according to the patient’s age when it is first diagnosed - into two types:

A. Dental crowding in children (or in the growth and development stage)
B. Dental crowding in adults, occurs unexpectedly (did not exist previously).
A-Dental crowding in children occurs due to many reasons, the most important of which are:

1- Genetics:
Genetics can play a role either in the small size of the jaw bone, or the big size of the teeth
themselves. While genes responsible for the teeth size differ from the genes responsible for the
jaw size, so the father can give the genes of large teeth, while the mother gives the genes of a
small jaw. And the result is that their child's teeth are crowded since there’s no sufficient space in the jaw bone to contain his large-sized teeth.

2-Dental caries in milk teeth:
The incidence of tooth decay among our children has increased due to:
•    the nature of the food we consume in our modern societies (sugars and sticky foods), that provides the appropriate
environment for the bacteria responsible for tooth erosion and decay formation.
•    In addition to the lack of dental cleaning care, and the lack of commitment to visiting the dentist periodically, on the pretext that children's teeth are temporary and there is no need to treat them, since they will be replaced by permanent teeth. But the truth is that treating children's milk teeth is very important to prevent dental crowding later. Milk teeth have an important role in preserving the space necessary for the permanent teeth to erupt and settle later. On the other hand, tooth decay is responsible for the loss of parts of the milk teeth, especially the lateral parts. It may also lead to the complete loss of the milk tooth prematurely. All of the above can cause dental crowding, since it allows the teeth surrounding the missing tooth to move and fill a part of the space (in which a permanent tooth will erupt later).

3- Delayed eruption of some permanent teeth:
This may occur due to some hormonal problems, or inherited genetics. The delay in eruption of some permanent teeth force the teeth adjacent to the space -of the non erupted teeth- to move and occupy part of that space, which lead to crowding 

 B – Late crowding in adults front teeth
As orthodontists, we often hear this complaint from our clients, that their lower front teeth were aligned well, but suddenly started to move and overlap, this usually happens after the age of 18 years.
This problem begins to appear in some adults between the age of 18 and 25, and crowding is usually concentrated in the lower front teeth. People and even some dentists connect this problem with the eruption of wisdom teeth, so is this relationship correct?

A lot of recent researches indicate to the invalidity of this hypothesis, because late crowding in adults lower front teeth is often happened in people don’t have wisdom teeth and in other hand we have people have erupted wisdom teeth, but they don’t suffer from lower anterior teeth crowding, so we cant connect scientifically between the two events.

There is a lot of theoretical explanations for this late unexpected crowding. One of these explanation is the late maturation of muscles around the mouth and on the chin, which started after age 18 and lead to increase in the tonicity of those muscles and therefore the pressure exerted on the lower anterior incisors, which lead to pushing those teeth backward and creation of late crowding problem. 
crowding can also be divided according to its severity into:

1- Mild Crowding
2- Moderate Crowding
3- Severe Crowding

Crowding is usually treated by various types of orthodontics appliances such as, Conventional metal braces, Invisalign Aligners, or even removable orthodontic appliances.
You can get additional information about orthodontic treatment types from the articles in the services section on this website.
But regardless of the type of orthodontic device used, the most important thing about orthodontic treatment of dental crowding is to provide sufficient space for the teeth to be aligned perfectly.

This distance is provided according to the severity of the case as the following:

1- Teeth stripping:
As we see in the picture, the enamel layer is in its thickest forms at the sides of the teeth. The
orthodontist can use special and safe devices - as in the picture – to remove a very small amount (less than 0.5 mm) from the enamel in these areas with no negative side effects such as sensitivity or tooth decay.
Teeth stripping gives enough distance to correct mild crowding, but in more severe cases, we will need other treatment methods.
 

2- Expanding jaws laterally:
Expanding the upper jaw using special orthodontic expansion devices (Orthodontic expanders) is not uncommon in orthodontics. As the expansion gives us sufficient space to correct mild or even moderate crowding. Expanders can be movable devices or attached to the teeth.
The orthodontist is the only person who can estimate whether it is possible to use this type of treatment or not because in some cases, expanding the jaw is not possible and other means must be used.
For more information, read the article about maxillary expansion in the services section of the website.

3- Teeth extraction.
We take the teeth extraction option in severe crowding cases in which the previously mentioned means are not sufficient. In these cases, we usually extract 4 teeth (a tooth on each side of the
upper and lower jaws), but in some cases fewer teeth are removed, according to the case.
We use the distance resulting from tooth extraction in aligning crowded teeth, and
We make sure to close the entire space of the extracted teeth by means of braces.

At the end of our article, we can confirm that the dental crowding problem is a cosmetic problem in the first place, because everybody wants perfectly aligned teeth, but we must not overlook the need to treat the problem orthodontically and quickly so that the patient can clean his teeth easily and efficiently. Since dental crowding reduces the efficiency of the teeth cleaning process, which leads to tooth decay and gum infections (Gingivitis).