Tooth development is a complex and lengthy process, starting in the early stages of life (still in the womb) and ending around 18-20 years of age. About how it proceeds, and what features characterize it, is described in this article.
Embryonic stage
Teeth are a derivative of the mucous membrane of the oral cavity of the embryo. The enamel organs develop from its epithelium. And from the mesenchyme under it - dentin, pulp, cementum and periodontium surrounding the tooth (soft and hard tissues). It is customary to distinguish three stages of development:
- Laying germs and teeth directly.
- Differentiation of primordia.
- Tooth formation.
The process is very interesting. The development of teeth begins at 6-7 weeks of the existence of the embryo. At this point, the epithelium on the surfaces of the oral cavity begins to thicken. Flask-shaped protrusions are also formed. Then they turn into enamel organs of milk teeth.
At the 10th week, mesenchyme grows into them. She is the rudiment of the dental papilla. By the end of the 3rd month, the enamel organs separate fromplates. Then the dental sac begins to form.
The third month is very active in terms of the formation of anatomical features. It accounts for the entire 2nd stage of tooth formation. The third begins at the end of the 4th month. At this stage, dental tissues already appear: tooth pulp, enamel, dentin. In general, the development of teeth takes about 5-6 months.
Important to know
The above process is actually a much more complex and multi-part process. It is important to know that dental maldevelopment is often the reason why solids are deposited incorrectly. Consequences can be:
- Formation of additional teeth.
- Enamel hypoplasia (underdevelopment).
- Incorrect arrangement of teeth in the jaw. This is also called dystopia.
- Dentin formation defects.
- Irregular shape of individual teeth.
- Erosion pits.
- Total or partial absence of teeth, also called edentulous.
It happens that completely he althy parents give birth to children who, as they grow older, have problems with their teeth.
To minimize the risk, you need to lead a he althy lifestyle (before and during pregnancy). Get more rest, give up bad habits, and enrich your diet with bran, herbs, dairy products, vegetables, nuts, fruits, fish and meat.
Enamel
Telling about the development of teeth, you need to briefly consider their structure. Enamel- this is their protective shell, as well as the hardest tissue in the human body. It is 97% composed of inorganic substances. The enamel is very thin, on the chewing part its thickness does not exceed 1.5-1.6 mm, and at the very base and on the side of the tooth it is several times thinner.
Enamel protects the dentin and pulp from external influences of a chemical and mechanical nature, and also from temperature irritants. It consists of enamel prisms and the so-called interprism substance.
It should be noted that although the enamel is strong, it is still exposed to various external influences. And any damage becomes a prerequisite for the development of caries.
Predisposing factors, of course, also exist. Often susceptibility to caries is caused by such factors:
- Inadequately matured tooth covering during eruption.
- No pellicle on tooth surface.
- Poor nutrition, excess carbon in the diet, lack of vitamins, proteins and valuable elements.
- Violation of the composition of saliva.
- Drinking water that is low in fluoride.
- Incomplete chemical composition and other deviations that occurred during the development of teeth.
Unfortunately, enamel is often exposed to various influences. It can collapse, often there is a wedge-shaped defect, some have pathological abrasion.
Dentine
This concept has already been mentioned earlier, in the process of discussing the stages of tooth development. Dentin is hardmain fabric. The crown part is covered with enamel, and the root part is covered with cement.
Mainly dentine is composed of hydroxyapatite (approximately 70%). It also contains organic material (20%) and water (10%).
Dentine is the foundation of the tooth and the support of the enamel. Its thickness varies from 2 to 6 mm. The hardness is impressive - 58.9 kgf/mm².
Within the framework of the topic on histology about the development of the tooth, it must be noted that dentin is divided into types. There are three in total:
- Primary. It is formed during the development of tooth tissues, until it erupts.
- Secondary. Formed throughout a person's life. Develops more slowly. It is characterized not by such a systemic placement of dentinal tubules, but also by many erythroglobular spaces, low mineralization and high permeability.
- Tertiary. It is also called irregular. It is formed during the preparation or trauma of the tooth, as well as during pathological processes (including caries).
Cement
This is a specific bone tissue, thanks to which the tooth is firmly fixed in the alveolus. Approximately 70% of cement consists of inorganic substances. It comes in two types:
- Primary. Adheres to dentin. It is he who covers the lateral surfaces of the root.
- Bone. It covers the area of bifurcation of multi-rooted teeth, as well as the apical 1/3 of the root.
Cellular cement is of particular interest. More precisely, its composition. This tissue is formed by cementoblasts, cementocytes and intercellularsubstance.
It protects dentin from damage, forms a supporting apparatus, provides attachment of periodontal fibers, and also participates in reparative processes.
Pulp
In the framework of the topic concerning the periods of tooth development, it is necessary to talk about this component. Pulp is a loose fibrous connective tissue with three layers - central, intermediate and peripheral.
Its blood circulation and innervation are carried out by venules, arterioles, jaw nerves and nerve branches. The pulp stimulates regenerative processes, and is also a kind of biological barrier that prevents harmful microorganisms from entering the periodontium from the carious cavity.
Also, its nerve formations regulate the process of feeding the tooth and the perception of various irritations.
Gingival connection
This is what strengthens the tooth in the alveolus of the jaw. This connection is formed by the periodontium, the cuticle of the tooth neck and stratified squamous epithelium.
This is not his only task. Thanks to periodontal, for example, the tooth is not only held in the socket of the jaw, but also absorbs the pressure exerted during chewing.
Breach of the integrity of this connection often leads to inflammation and infection.
Age changes
Above, something was said about the development of milk teeth. During the first 12-15 years of a person's life, they are successively replaced by indigenous ones. cut through firstthe first molar, then the central and lateral incisors. Then premolars with fangs are shown, and only after 20-25 years - the so-called "wisdom tooth".
As a person grows older, there are some changes in structure and composition. This is not a violation of the development of the teeth, but a normal phenomenon. Enamel with dentin is gradually erased, plaque appears, some even crack. The amount of organic compounds present in the composition is reduced. The permeability of both enamel and dentin with cement is weakened.
The pulp atrophies over time. The reason for this is poor nutrition and sclerotic changes in blood vessels. Approximately after 40-50 years, they are also detected in the periodontium. Also at this time, collagen fibers coarsen and cell organelles are reduced.
The importance of a he althy lifestyle
It's a paradox, but teeth, while very strong, are actually quite fragile. If a person eats poorly, it will quickly affect their condition. We must remember that teeth need vitamins, because they:
- Improve metabolism.
- Nourish the circulatory system, nerves and bone tissue.
- Strengthen enamel.
From an early age, you need to take care of the condition of your teeth. It is very important for children to take useful substances in a course. They need calcium for tooth growth, B vitamins for he althy gums, and A for he althy bone development.
And never ignore discomfort. If your teeth hurt, you need to contact the dentist, and also starttake vitamin D heavily. It is its lack that most often causes caries.
If the teeth have become rough, it means that the body lacks vitamin A. It also causes problems with mucous surfaces and loosening of teeth. The process of salivation is also often disrupted, which damages the enamel.
And inflammation of the gums or tooth loss is the most alarming signal. These conditions are preceded by a lack of vitamins B and C, but such pathologies cannot be cured by their active consumption. Here you will need the help of a specialist. And in general, it is recommended to visit the dental office at least once every six months for the sake of prevention.
