The development of teeth is a complex and lengthy process, starting in the early stages of the origin of life (even in the womb) and ending in about 18-20 years. About how it proceeds, and what features characterize it, is described in this article.
Embryonic stage
Teeth is a derivative of the mucous membrane of the oral cavity of the embryo. Enamel organs develop from its epithelium. And from the mesenchyme located under it - dentin, pulp, cement and periodontium surrounding the tooth (soft and hard tissues). It is customary to distinguish three stages of development:
- Bookmark rudiments and teeth directly.
- Differentiation of primordia.
- Teeth 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. Bulb-shaped protrusions are also formed. Then they turn into enamel organs of milk teeth.
At the 10th week, mesenchyme grows in them. She is the rudiment of a dental papilla. By the end of the 3rd month, the enamel organs are separated from the plate. Then a tooth 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 the formation of teeth. 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.
It's important to know
The above process is in fact a much more complex and multi-part process. It is important to know that impaired dental development often becomes the reason why solids are not deposited properly. The consequences may be:
- The formation of additional teeth.
- Enamel hypoplasia (insufficient development).
- Incorrect positioning of teeth in the jaw. This is also called dystopia.
- Dentin formation defects.
- Irregular shape of individual teeth.
- Erosion pits.
- Complete or partial absence of teeth, also called adentia.
It happens that in completely healthy parents children are born who, as they grow older, have problems with their teeth.
To minimize the risk, you need to lead a healthy lifestyle (before and during pregnancy). Relax more, give up bad habits, and enrich the diet with bran, herbs, dairy products, vegetables, nuts, fruits, fish and meat.
Enamel
Talking about the development of teeth, you need to briefly consider their structure. Enamel 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 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 must be noted that although enamel is strong, it is nevertheless subjected to various external influences. And any damage becomes prerequisites for the development of caries.
Predisposing factors, of course, also exist. Often, susceptibility to caries is determined by such factors:
- Inadequately matured tooth cover during teething.
- Lack of pellicles on the surface of the tooth.
- Poor nutrition, excess carbon in the diet, lack of vitamins, proteins and valuable elements.
- Violation of the composition of saliva.
- Drinking water that contains little fluoride.
- Incomplete chemical composition and other deviations that occurred during the development of teeth.
Unfortunately, enamel is often exposed to various influences. It can be destroyed, a wedge-shaped defect often arises, some have pathological abrasion.
Dentine
This concept has already been mentioned earlier, in the process of discussing the stages of tooth development. Dentin is its hard tissue, which is the main. The crown part is covered with enamel, and the root is covered with cement.
Mostly dentin consists of hydroxyapatite (approximately 70%). Also in its composition is organic material (20%) and water (10%).
Dentin is the basis of the tooth and enamel support. Its thickness varies from 2 to 6 mm. The hardness is impressive - 58.9 kgf / mm².
In the framework of the topic of histology about tooth development, it should be noted that dentin is divided into types. There are three of them:
- Primary. It is formed in the process of tooth tissue development, until it erupts.
- Secondary. It is formed throughout the life of a person. It develops more slowly. It is characterized not by such a systematic placement of the dentinal tubules, but also by a multitude of erythroglobular spaces, low salinity and high permeability.
- Tertiary. It is also called irregular. It is formed during dissection or tooth injuries, as well as in processes of a pathological nature (among them caries).
Cement
This is a specific bone tissue, due to which the tooth is firmly attached to the alveolus. About 70% of the cement consists of inorganic substances. It is of two types:
- Primary. Belongs 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 intercellular substance.
It protects dentin from damage, forms a supporting apparatus, ensures the attachment of periodontal fibers, and also participates in reparative processes.
Pulp
In the framework of the topic relating to periods of development of teeth, it is necessary to talk about this component. A pulp is called loose fibrous connective tissue with three layers - central, intermediate and peripheral.
Her blood circulation and innervation are carried out due to venules, arterioles, jaw nerves and nerve branches. Pulp stimulates regenerative processes, and is also a kind of biological barrier that prevents the entry of harmful microorganisms into the periodontium from the cavity.
Also, its nerve formations regulate the process of tooth nutrition and its perception of various irritations.
Gingival junction
This is how the tooth is strengthened in the jaw alveolus. This compound is formed by periodontal, cuticle of the tooth neck and stratified squamous epithelium.
This is not his only task. Thanks to periodontal treatment, for example, a tooth is not only held in the socket of the jaw, but also absorbs the pressure exerted during chewing.
Violation of the integrity of this compound often leads to inflammation and infection.
Age-related changes
Something was said above about the development of primary teeth. During the first 12-15 years of a person’s life, they are successively replaced by indigenous ones. First, the first molar is cut, 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 up, some changes in structure and composition occur. This is not a violation of the development of teeth, but a normal phenomenon. Enamel with dentin is gradually erased, a plaque appears, some even have cracks. The amount of organic compounds present in the composition is reduced. The permeability of both enamel and dentin with cement is weakened.
The pulp will atrophy over time. The reason for this is poor nutrition and sclerotic changes in blood vessels. After about 40-50 years, they are also detected in the periodontium. Also, collagen fibers coarsen at this time and cellular organelles are reduced.
The importance of a good lifestyle
A paradox, but the teeth, being very strong, are actually quite fragile. If a person eats poorly, this will quickly affect their condition. We must remember that vitamins are necessary for teeth, because they:
- Improve metabolism.
- Nourish the circulatory system, nerves and bone tissue.
- Strengthen the enamel.
From an early age, you need to take care of the condition of the teeth. It is very important for children to take nutrients in the course. They need calcium for tooth growth, vitamins B to maintain gum health, and A for the full development of bone tissue.
And in no case can you ignore the discomfort. If your teeth hurt, you need to consult a dentist, and also begin to take vitamin D intensively. It is its lack that most often causes tooth decay.
If the teeth become rough, it means that the body lacks vitamin A. It is the cause of problems with mucous surfaces and loosening of the teeth. The salivation process is often disturbed, due to which the enamel is damaged.
And gum disease or tooth loss is the most alarming signal. A deficiency of vitamins B and C is preceded by these conditions, but such pathologies cannot be cured by their active consumption. Here, the help of a specialist will already be needed. Anyway, it is recommended that you visit the dental office at least every six months for the sake of prevention.