The internal structure of human teeth
In humans, the complex structure of the tooth. With the help of the dentition is a primary mechanical processing of food. This is due to the phylogenetic origin of teeth that helps them to perform their functions.
The anatomical structure of the teeth quite difficult. They are not exposed to physiological recovery. Enamel is a strong material, but under the influence of different factors, it is prone to destruction.
Milk teeth are fragile structures as they appear for a short time. But the constant elements of the dentition remain with the person throughout his life. Dentists distinguish the following types of teeth:
- incisors — located in the center and the side;
In medicine, the teeth on the jaws is indicated by a special formula. Symbols used Arabic and Roman numerals. Wisdom teeth are arranged so that they can appear in person only in adulthood, and may not appear at all. When all the last molars grow, a person has 32 teeth. But when they do not germinate, their number is 28 pieces.
How the elements
Teeth located on the upper and lower jaws. They are surrounded by other anatomical structures. The plot of jaws with a tooth and the anatomical structures surrounding it, called a dentoalveolar segment.
It consists of the following elements:
- the tooth;
- the alveolus with an adjacent portion of the jaw;
- the mucous membrane that covers the jaw;
- the device that fixes the tooth to the alveolus;
- blood vessels and nerve endings.
Teeth contribute to a better processing of food enzymes the mouth. But their shape is different. Dairy items appear to 2 years. Then they fall, and in their place appear indigenous counterparts.
Scheme of structure of the tooth includes the following parts:
- crown — the visible and stout structure;
- the neck is between the root and the crown;
- the root is in the depth of the alveoli
- the tip of the root is at the end of the root.
Due to the different functional features of the teeth contain a different number of roots. There are from 1 to 3 pieces. Stomatologichesky in the structure of human teeth is composed of only the crown and the root. Clinical crown — portion of tooth that is above the surface of the gums. Clinical root — that part of tooth which is placed directly in the cavity of the alveoli. With age against the background of physiological atrophy of the gums, the size of the clinical crown increase. Clinical root loses its dimensions.
What is the dentin
Consider the substance resembles coarse-fibered bone tissue. Unlike her, she has no cells, but more durable. Dentin is formed by the processes of the cells odontoblasts. They are located in the outer parts of the pulp.
The structure of the dentine: the outer layer — the mantle (distinguenda area) and the inner layer of near-pulp. The anatomy of the enamel consists of prisms is thin but long structure. Enamel is composed entirely of mineral salts. So it is the most durable material in the human body.
The cement consists of coarse-fibered bone tissue is impregnated with salts. The collagen fibers located in the cement in different directions. Cement has no blood vessels, its nutrition is derived from the periodontium with the help of diffusion.
The tooth is attached to the alveolus with the help of many bundles of connective tissue. Combining data bundles located between the alveolus and tooth cementum. Such an accumulation is called periodontal. All anatomical structures that surround the root of the tooth are named as periodontium.
What is pulp
The structure of the permanent teeth includes a cavity that may have a different shape. The cavity of the crown repeats the shape of the crown. Then the cavity goes down to the root, which is to the top, tapering gradually. At the top of the element it ends with hole. When a tooth has two or three roots, holes will be the same. The walls of the cavity at the top, and at the closing constitute the top of the element, called set.
If the top of the tooth is the chewing cusps, then the arch has a deepening. Part of the cavity, where it begins the root canal, called the bottom of the cavity. If the root canal is only one, the bottom smoothly into the channel. Is such that channels 2 or 3, then the bottom flatter. There are holes for each root.
The pulp is connective tissue of the particular structure. It is filled with vessels and nerves. It contains cellular elements.
The internal structure of the tooth — a complex structure of the human body. Solid base element is formed by dentin — a substance similar to bone. Dentin determines what will be the form of the tooth. The substance, which consists of crown covered with enamel. The element from which is formed the root, covered with cement. In place of the neck connects with the cement enamel in different ways:
- enamel goes on cement, cover it;
- cement goes on the enamel, covering it;
- when connecting enamel and cement formed a joint;
- enamel and cement is partially connected, in this case, there is a part of bare dentine.
Healthy human teeth are covered with enamel and solid cuticle.
The upper jaw
The structure of human teeth in the upper jaw are considered for each element separately. Central incisor — a tooth with a flattened crown and a tapered root. Side of the crown adjacent to the lip has a convex shape. Upstairs there are 3 crowns of the bump. Member directly slightly sloping to the outside.
If we consider the lateral incisor, the anatomical structure of the tooth resembles the shape of the bit. He has 3 tubercles. The Fang of a convex front side. On the side, which is adjacent to the tongue, a furrow. She shared the crown in half. At the top of the crown is 1 bump.
The location should be the first molar. When writing a dental formula designated by the number 4. It is shaped like a prism. He convex side. The first bump is larger than the second. The root is bifurcated system structure.
Device premolars differ in their structure. The largest tooth is the first molar. Another of his name — a big molar. The shape of its crown resembles a rectangle, and the form of chewable parts — diamond. He is responsible for good chewing of food. Consider the cutter has the highest number of roots — 3.
The second molar is smaller than the first. Is shaped like a cube. the Bumps from the cheeks more than the bumps from the language. The presence of a third molar may not all people. It is called the wisdom tooth, the shape of which is similar to the previous item. The only difference is the shape of the root. Here it forms a short fat pole.
The lower jaw
To find out how human tooth, scheme is used. The elements on the upper and lower jaws have the same name but different structure. From Central incisor the lingual part is concave and the Bucco — convex. The size of the lateral incisor more than the previous. But compared to others it is small. The top edge of the cutter has two angles. The medial angle is more acute than the lateral. The element has one root — flat, thin. It contains grooves in the longitudinal direction.
The second premolar larger than the previous one, but the bumps have the same shape. Their location on the chewing surfaces are completely symmetrical. The fissure that runs between the two gorbachami, shaped like a horseshoe. The root is the same as the previous cutter.
On the first molar of the cubic form there are 5 hillocks, which are good for the chewing of food. Three of the five mounds are located on the buccal side and two on the lingual. The number of roots 2 full bathrooms. The anterior root has two channels. The second molars are completely identical to the tooth located on the maxilla. The third molar differs from the second arrangement of tubercles on the chewing surface.
Scheme of structure of milk teeth is the same as the indigenous counterparts. They differ in a significant difference in the quantity and some aspects of the structure. Dairy items is less than the root. On the internal structure of the first incisors are less generalizirovanny, respectively, have less strength. Therefore, they are more prone to caries.
The cavity also has its differences. In the milk incisors it is large, and therefore the pulp in them anymore. They often become inflamed, causing pain. Bumps are mild, as this dentition requires low functionality.
But dairy incisors more convex form. They are more acute. The root apex is directed towards the lips. Baby teeth are removed easier and without pain. This is because they have small roots. They are not associated with alveoli.
The presence of these differences is caused by problems with your teeth appear in children more often than adults. People should know that it is necessary to carefully monitor the condition of the dentition since childhood. Throughout life teeth are subject to heavy loads. Each element performs a specific function.