Advertising on the portal

Diagram of the structure of a tooth. Dentin is the bone substance of the tooth. Modern and ancient teeth

Dentin is the main substance that gives color to teeth and protects them from the negative influence of harmful factors. The strength of its structure is much stronger than bone tissue. This material gives the tooth its shape and ensures its elasticity. It is important to know how this tissue is constructed, as well as its chemical composition. In addition, you need to have an idea of ​​what happens to the tissue of this part of the tooth during pathological processes of the teeth. This will help maintain a strong dentin structure and good dental health for a long time.

Dentin is a specialized connective tissue that makes up the bulk of the tooth along its entire length. It has much in common with bone tissue, but unlike bone, dentin is more mineralized.

Dentin is considered a calcified substance that contains mineral components. Due to this component of the tooth, micronutrients are carried through the tubules to the enamel, which protect the pulp from various negative influences.

Attention! Dentin refers to the inner part of the tooth. In its structure, it is much stronger and harder than bone tissue, but it is softer than the enamel that covers it. In addition, it has increased elasticity, this property resists its destruction.


The thickness of dentin in the chewing and cervical areas has some differences. Its parameters can be from 2 to 6 mm, it all depends on the health and condition of each patient’s body. In its structure, this component has a yellow or gray tint, which is considered the natural color of teeth.
Please note that the dentin coverage varies in different areas of the tooth. In the coronal part, this is enamel, which can be seen during visual inspection. In the root area, this coating is replaced by a cement base, which is not very strong in structure. The connection of dentin to enamel usually occurs due to special irregularities with a perfect fit to each other.

Features of histological structure

Dentin consists of the following types of tissues:

  • predentin. This type of tissue surrounds the dental pulp area and provides it with various beneficial components.

    Important! The main component of this tissue is odontoblasts, pear-shaped cells. Due to these elements, tooth sensitivity is ensured, and metabolism inside its cavity also occurs;

  • interglobular part. This element provides filling of the area between the dentin tubes. There is also a separate classification of this component - peripulpal dentin and mantle dentin.

The first type is usually located around the pulp area, and the second type is adjacent to the enamel:


Components

The chemical composition of dentin has some differences when compared with the composition of other tissues. The largest part, almost 70%, contains inorganic substances:

  1. The base is calcium phosphate;
  2. Magnesium phosphate;
  3. Calcium fluoride;
  4. Sodium carbonate and calcium.

The remaining part, namely 20%, contains substances with an organic structure - collagen, amino acids, lipids, polysaccharides. The remaining 10% consists of water.

Important! Due to its diverse composition, dentin is considered a very hard and durable tissue with a high degree of elasticity. For this reason, it protects the enamel structure from cracking and also allows it to withstand increased chewing loads.


In addition, the composition contains some macroparticles and microelements. In its structure, dentin tissue is much stronger than bone and cement tissue. But at the same time, dentin is almost 5 times softer than enamel, but it is worth highlighting two important conditions:
  • Despite the fact that the enamel coating is considered hard, it is also very fragile. For this reason, the enamel can quickly crack;
  • dentin is the basis of the crown. It provides increased protection to the enamel coating from premature cracks.

Dentin contains less calcareous components than tooth enamel. It mainly consists of calcium phosphate, magnesium phosphate, calcium fluoride, sodium carbonate and calcium, and also contains amino acids.

Species

There are three types in total - primary, secondary, tertiary.
The primary form of dentin is noted at the earliest stage of the formation and development of this tooth material. This means that this variety exists in humans only until the appearance of the first units of the dentition.
After the first teeth appear, they begin to perform their natural functions. At this time, they undergo a transformation of primary dentin into secondary. Unlike the primary form, this species has a slower growth rate, and the structure also becomes less regular. It is worth noting that the structure of this species differs little from the primary form of dentin. At the same time, milk teeth have wide dentinal tubules with a small length. It is this factor that ensures easy access of pathogenic microorganisms into the pulp cavity. Permanent teeth have long and narrow dentinal tubules.
The process of synthesizing secondary dentin in humans occurs throughout life, and in men it happens much faster, unlike in women. Due to the fact that secondary dentin is deposited inside the tubules, the size of the lumen of the pulp cavity becomes narrow with age. Sometimes the lumen may close completely.
The tertiary form has some peculiarity - its irregularity. This type usually manifests itself as a result of exposure of dentinal tissue to various irritating factors:

  • erosive lesion;
  • caries formation;
  • the presence of abrasion of units of the dentition;
  • grinding of teeth.

Dentin caries is accompanied by a violation of the integrity of the tooth with the formation of a cavity. But often the carious cavity is not visualized and is discovered only at a dentist’s appointment when probing the tooth with a special instrument for diagnosing caries.

The irregularity of this type of dentin is explained by the fact that the tortuous tubes in it are arranged in a chaotic state. In addition, this property provides increased enamel protection. When a strong pathological process occurs, the tubules may completely disappear.

What are the types of dentin diseases?

Attention! When a tooth is damaged, the doctor usually diagnoses it as a moderate form of carious lesion. When food debris gets into the resulting cavity after a carious lesion, patients may complain of hyperesthesia, which is characterized by increased sensitivity and severe irritability when the tooth is exposed to hot or cold.

In advanced forms, painful sensations appear.
If timely treatment is not started, severe complications may result, and pathogenic bacteria may penetrate into the pulp area. If an inflammatory process occurs, the doctor can completely remove dead tissue. After this operation, all metabolic processes in the dentin completely stop.
It is also worth highlighting particularly dangerous diseases that occur in the internal structure of the tooth:

  1. Carious lesion of any form;
  2. Increased degree of enamel abrasion;
  3. Wedge-shaped defect;
  4. Hypersthesia. This disease can manifest itself independently or as a complication resulting from the appearance of the above pathologies.

A wedge-shaped defect is a non-carious lesion that occurs on the hard tissues of teeth, characterized by the formation of a wedge-shaped defect in the area of ​​the tooth neck.

Dentin restoration process

Regeneration of dentinal tissue occurs due to the functioning of odontoblasts. This process usually occurs in cases where the innervation of the dental epithelium is healthy and undisturbed. If the nerve is completely removed from a healthy tooth, then dentin restoration stops.
Many world scientists in the field of dentistry, especially American ones, have been able to make the best progress in the field of dentin restoration. It was they who were able to make a wide range of discoveries, which in the future can ensure the natural restoration of dentin in the presence of its severe destruction. In laboratories, thanks to the activation of the necessary genes, it was possible to create a healthy natural tooth.
Subsequent research work consists of an attempt to restore the structure at the micromechanical level. By using colloidal compounds of calcium phosphate, saline solution, collagen, and electrical discharges, scientists were able to obtain a biocomposite type material that fully matches the natural structure of a natural tooth.

Important! But nowadays, in order to perform routine dentin restoration, vitamin-mineral complexes are used. The following components are of particular importance for the nutrition of dentin: magnesium, calcium, phosphorus, vitamins A, B, C, E and D.


In addition, to ensure high strength and health of dentin, it is recommended to maintain regular oral hygiene using a special toothpaste. It is recommended to clean your teeth using circular movements; the cleaning procedure should last at least 3 minutes. You also need to eat right.

54045 0

Human teeth are an integral part chewing-speech apparatus, which, according to modern views, is a complex of interacting and interconnected organs that take part in chewing, breathing, and the formation of voice and speech. This complex includes: solid support - the facial skeleton and the temporomandibular joint; chewing muscles; organs designed for grasping, moving food and forming a bolus of food, for swallowing, as well as the sound-speech apparatus: lips, cheeks, palate, teeth, tongue; organs for crushing and grinding food - teeth; organs that serve to soften and enzymatically process food are the salivary glands of the oral cavity.

Teeth are surrounded by various anatomical structures. They form metameric dentition on the jaws, so the area of ​​the jaw with the tooth belonging to it is designated as dentofacial segment. There are dentofacial segments of the upper jaw (segmenta dentomaxillares) and lower jaw (segmenta dentomandibularis).

The dentofacial segment includes the tooth; the dental alveolus and the part of the jaw adjacent to it, covered with mucous membrane; ligamentous apparatus, fixing the tooth to the alveolus; vessels and nerves (Fig. 1).

Rice. 1.

1 - periodontal fibers; 2 - alveolar wall; 3 - dentoalveolar fibers; 4 - alveolar-gingival branch of the nerve; 5 - periodontal vessels; 6 - arteries and veins of the jaw; 7 - dental branch of the nerve; 8 - bottom of the alveoli; 9 - tooth root; 10 - neck of the tooth; 11 - tooth crown

Human teeth belong to the heterodont and thecodont systems, to the diphyodont type. First, milk teeth (dentes decidui) function, which appear completely (20 teeth) by the age of 2 years, and then are replaced permanent teeth(dentes permanents) (32 teeth) (Fig. 2).

Rice. 2.

a - upper jaw; b - lower jaw;

1 - central incisors; 2 - lateral incisors; 3 - fangs; 4 - first premolars; 5 - second premolars; 6 - first molars; 7 - second molars; 8 - third molars

Parts of a tooth. Each tooth (dens) consists of a crown (corona dentis) - a thickened part protruding from the jaw alveolus; neck (cervix dentis) - the narrowed part adjacent to the crown, and root (radix dentis) - the part of the tooth lying inside the alveolus of the jaw. The root ends apex of tooth root(apex radicis dentis) (Fig. 3). Functionally different teeth have an unequal number of roots - from 1 to 3.

Rice. 3. Tooth structure: 1 - enamel; 2 - dentin; 3 - pulp; 4 - free part of the gum; 5 - periodontium; 6 - cement; 7 - tooth root canal; 8 - alveolar wall; 9 — hole in the apex of the tooth; 10 - tooth root; 11 - neck of the tooth; 12 — tooth crown

In dentistry there are clinical crown(corona clinic), which is understood as the area of ​​the tooth protruding above the gum, as well as clinical root(radix clinic)- the area of ​​the tooth located in the alveolus. The clinical crown increases with age due to gum atrophy, and the clinical root decreases.

Inside the tooth there is a small dental cavity (cavitas dentis), the shape of which is different in different teeth. In the crown of a tooth, the shape of its cavity (cavitas coronae) almost repeats the shape of the crown. Then it continues to the root in the form root canal (canalis radicis dentis), which ends at the tip of the root hole (foramen apices dentis). In teeth with 2 and 3 roots there are, respectively, 2 or 3 root canals and apical foramina, but the canals can branch, bifurcate and reconnect into one. The wall of the tooth cavity adjacent to its closure surface is called the vault. In small and large molars, on the occlusal surface of which there are chewing tubercles, corresponding depressions filled with pulp horns are noticeable in the vault. The surface of the cavity from which the root canals begin is called the floor of the cavity. In single-rooted teeth, the bottom of the cavity narrows funnel-shaped and passes into the canal. In multi-rooted teeth, the bottom is flatter and has holes for each root.

The tooth cavity is filled pulp of the tooth (pulpa dentis)- loose connective tissue of a special structure, rich in cellular elements, vessels and nerves. According to the parts of the tooth cavity, they are distinguished crown pulp (pulpa coronalis) And root pulp (pulpa radicularis).

General tooth structure. The hard base of the tooth is dentin- a substance similar in structure to bone. Dentin determines the shape of the tooth. The dentin that forms the crown is covered with a layer of white dental enamel (enamelum), and root dentin - cement (cementum). The junction of the crown enamel and root cement is at the neck of the tooth. There are 3 types of connection between enamel and cement:

1) they are connected end-to-end;

2) they overlap each other (enamel overlaps cement and vice versa);

3) the enamel does not reach the edge of the cement and an open area of ​​dentin remains between them.

The enamel of intact teeth is covered with a durable, lime-free cuticle enamel (cuticula enameli).

Dentin is the primary tissue of teeth. In structure it is similar to coarse-fiber bone and differs from it in the absence of cells and greater hardness. Dentin consists of cell processes - odontoblasts, which are located in the peripheral layer of the tooth pulp, and the surrounding main substance. It contains a lot dentinal tubules (tubuli dentinales), in which the processes of odontoblasts pass (Fig. 4). In 1 mm 3 of dentin there are up to 75,000 dentinal tubules. In the dentin of the crown near the pulp there are more tubes than in the root. The number of dentinal tubules varies in different teeth: in incisors there are 1.5 times more of them than in molars.

Rice. 4. Odontoblasts and their processes in dentin:

1 - mantle dentin; 2 - peripulpal dentin; 3 - predentin; 4 - odontoblasts; 5 - dentinal tubules

The main substance of dentin, lying between the tubules, consists of collagen fibers and a substance that glues them together. There are 2 layers of dentin: outer - mantle and inner - peripulpar. In the outer layer, the fibers of the main substance run at the top of the tooth crown in the radial direction, and in the inner layer - tangentially with respect to the tooth cavity. In the lateral sections of the crown and in the root, the fibers of the outer layer are located obliquely. In relation to the dentinal tubules, the collagen fibers of the outer layer run parallel, and the inner layer runs at a right angle. Mineral salts (mainly calcium phosphate, calcium carbonate, magnesium, sodium and hydroxyapatite crystals) are deposited between the collagen fibers. Calcification of collagen fibers does not occur. Salt crystals are oriented along the fibers. There are areas of dentin with slightly calcified or completely uncalcified ground substance ( interglobular spaces). These areas can increase during pathological processes. In older people, there are areas of dentin in which the fibers are also susceptible to calcification. The innermost layer of peripulpar dentin is not calcified and is called dentinogenic zone (predentin). This zone is the place constant growth of dentin.

Currently, clinicians distinguish the morphofunctional formation endodontium, which includes pulp and dentin adjacent to the tooth cavity. These dental tissues are often involved in the local pathological process, which led to the formation of endodontics as a branch of therapeutic dentistry and the development of endodontic instruments.

The enamel consists of enamel prisms (prismae enameli)- thin (3-6 microns) elongated formations, running in waves through the entire thickness of the enamel, and gluing them together interprismatic substance.

The thickness of the enamel layer varies in different parts of the teeth and ranges from 0.01 mm (at the neck of the tooth) to 1.7 mm (at the level of the chewing cusps of the molars). Enamel is the hardest tissue of the human body, which is explained by its high (up to 97%) content of mineral salts. Enamel prisms have a polygonal shape and are located radially to the dentin and the longitudinal axis of the tooth (Fig. 5).

Rice. 5. The structure of the human tooth. Histological specimen. Uv. x5.

Odontoblasts and their processes in dentin:

1 - enamel; 2 - oblique dark lines - enamel stripes (Retzius stripes); 3 — alternating enamel stripes (Schreger stripes); 4 - tooth crown; 5 - dentin; 6 - dentinal tubules; 7 - neck of the tooth; 8 - tooth cavity; 9 - dentin; 10 - tooth root; 11 - cement; 12 - tooth root canal

Cementum is coarse fibrous bone, consisting of main substance, impregnated with lime salts (up to 70%), in which collagen fibers run in different directions. The cement on the root tips and on the interroot surfaces contains cells - cementocytes, lying in the bone cavities. There are no tubes or vessels in the cement; it is nourished diffusely from the periodontium.

The root of the tooth is attached to the alveolus of the jaw through many bundles of connective tissue fibers. These bundles, loose connective tissue and cellular elements form the connective tissue membrane of the tooth, which is located between the alveolus and cement and is called periodontium. The periodontium plays the role of the internal periosteum. This attachment is one of the types of fibrous connection - dentoalveolar connection (articulation dentoalveolaris). The set of formations surrounding the tooth root: periodontium, alveolus, the corresponding section of the alveolar process and the gum covering it is called periodontal (parodentium).

The tooth is fixed using periodontal tissue, the fibers of which are stretched between the cement and the bone alveolus. The combination of three elements (bone dental alveolus, periodontium and cementum) is called supporting apparatus of the tooth.

The periodontium is a complex of connective tissue bundles located between the bone alveolus and cement. The width of the periodontal gap in human teeth is 0.15-0.35 mm near the mouth of the alveolus, 0.1-0.3 mm in the middle third of the root, and 0.3-0.55 mm at the root apex. In the middle third of the root, the leriodontal gap has a constriction, so it can be roughly compared in shape to an hourglass, which is associated with micromovements of the tooth in the alveolus. After 55-60 years, the periodontal fissure narrows (in 72% of cases).

Many bundles of collagen fibers extend from the wall of the dental alveoli to the cementum. In the spaces between the bundles of fibrous tissue there are layers of loose connective tissue in which cellular elements (histiocytes, fibroblasts, osteoblasts, etc.), vessels and nerves lie. The direction of bundles of periodontal collagen fibers is different in different sections. At the mouth of the dental alveolus (marginal periodontium) in the retaining apparatus, one can distinguish dentogingival, interdental and dentoalveolar group bundles of fibers (Fig. 6).

Rice. 6. Structure of the periodontium. Cross-section at the level of the cervical part of the tooth root: 1 - dentoalveolar fibers; 2 - interdental (interroot) fibers; 3 - periodontal fibers

Dental fibers (fibrae dentogingivales) begin from the root cement at the bottom of the gingival pocket and spread fan-shaped outward into the connective tissue of the gums.

The bundles are well expressed on the vestibular and oral surfaces and relatively weakly on the contact surfaces of the teeth. The thickness of the fiber bundles does not exceed 0.1 mm.

Interdental fibers (fibrae interdentaliae) form powerful beams 1.0-1.5 mm wide. They extend from the cementum of the contact surface of one tooth through the interdental septum to the cementum of the adjacent tube. This group of bundles plays a special role: it maintains the continuity of the dentition and participates in the distribution of chewing pressure within the dental arch.

Dentoalveolar fibers (fibrae dentoalveolares) start from the cementum of the root along the entire length and go to the wall of the dental alveoli. Bundles of fibers begin at the apex of the root, spread almost vertically, in the apical part - horizontally, in the middle and upper thirds of the root they go obliquely from bottom to top. On multi-rooted teeth, the tufts go less obliquely; in places where the root is divided, they follow from top to bottom, from one root to another, crossing each other. In the absence of an antagonist tooth, the direction of the beams becomes horizontal.

The orientation of bundles of periodontal collagen fibers, as well as the structure of the spongy substance of the jaws, are formed under the influence of functional load. In teeth devoid of antagonists, over time, the number and thickness of periodontal bundles become smaller, and their direction turns from oblique to horizontal and even oblique in the opposite direction (Fig. 7).

Rice. 7. Direction and severity of periodontal bundles in the presence (a) and absence of an antagonist (b)

Human anatomy S.S. Mikhailov, A.V. Chukbar, A.G. Tsybulkin

3. Milk and permanent teeth, their structure, replacement. Dentition, formula of milk and permanent teeth. Blood supply and innervation of teeth.

Teeth, dentes, are ossified papillae of the mucous membrane, used for mechanical processing of food. Phylogenetically, teeth come from fish scales that grow along the edge of the jaws and acquire new functions here. Due to wear and tear, they are repeatedly replaced by new ones, which is reflected in the change of teeth, which in lower vertebrates occurs many times throughout life, and in person twice:

1) temporary, milk, dentes decidui

2) permanent, dentes permanentes

Sometimes there is a 3rd shift. (A case of the 3rd change of teeth in a 100-year-old man was observed). Types of teeth:

3. Premolars

The teeth are located in the cells of the alveolar processes of the upper and lower jaws, connecting using the so-called hammering, gomphosis, (gomphos, Greek - nail) (the name is incorrect, since in fact the teeth are not hammered in from the outside, but grow from the inside - an example of formalism in descriptive anatomy). The tissue covering the alveolar processes is called gums, gingivae. The mucous membrane here, through fibrous tissue, tightly fuses with the periosteum; Gum tissue is rich in blood vessels (so it bleeds relatively easily), but is poorly supplied with nerves. The grooved depression located between the tooth and the free edge of the gum is called a gum pocket.

Each tooth, dens, consists of:

1. Tooth crowns, corona dentis

2. Cervix, collum dentis

3. Roots, radix dentis

The crown protrudes above the gum, the neck (a slightly narrowed part of the tooth) is covered by the gum, and the root sits in the dental alveolus and ends at the apex, apex radicis, on which even the naked eye can see a small opening at the apex - foramen apicis. Through this hole, blood vessels and nerves enter the tooth. Inside the crown of the tooth there is a cavity, сavitas dentis, in which a distinction is made between the coronal section, the most extensive part of the cavity, and the root section, the tapering part of the cavity, called the root canal, canalis radicis.

The canal opens at the apex with the apical opening mentioned above. The tooth cavity is filled with dental pulp, pulpa dentis, rich in blood vessels and nerves. Dental roots grow tightly together with the surface of the dental cells through the alveolar periosteum, periodontium, rich in blood vessels. The tooth, periodontium, alveolar wall and gum make up the dental organ.

The hard substance of the tooth consists of:

1) dentin, dentinum

2) enamels, enamelum

3) cement, cementum

The main mass of the tooth surrounding the tooth cavity is dentin. The enamel covers the outside of the crown, and the root is covered with cement.

The teeth are enclosed in the jaws in such a way that the crowns of the teeth are on the outside and form the dentition - upper and lower. Each dentition contains 16 teeth arranged in the form of a dental arch.

Each tooth has 5 surfaces:

1) facing the vestibule of the mouth, facies vestibularis, which at the front teeth comes into contact with the mucous membrane of the lip, and at the rear teeth - with the mucous membrane of the cheek;

2) facing the oral cavity, towards the tongue, facies lingualis;

3 and 4) in contact with neighboring teeth of their row, facies contactus. The contact surfaces of the teeth directed towards the center of the dental arch are designated as facies mesialis (meso, Greek - between). In the front teeth this surface is medial, and in the back teeth it is the anterior surface. The contact surfaces of the teeth directed in the direction opposite to the center of the dentition are called distal, facies distalis. In the anterior teeth this surface is lateral, and in the posterior teeth it is posterior;

5) chewing surface, or the surface of closure with the teeth of the opposite row, facies occlusalis.

Eruption of baby teeth, i.e. thinning of the gums and the appearance of a tooth crown in the oral cavity, begins in the 7th month of extrauterine life (the medial lower incisors erupt first) and ends by the beginning of the 3rd year. There are only 20 baby teeth. Their dental formula is:

The numbers indicate the number of teeth on half of each jaw (upper and lower): two incisors, one canine, two large molars. After six years, the replacement of baby teeth with permanent ones begins. It consists of erupting new additional teeth in excess of 20 milk teeth and replacing each milk tooth with a permanent one. The eruption of permanent teeth begins with the first large molar (six-year-old molar), by the age of 12-13 the eruption of permanent teeth ends, with the exception of the third large molar, which erupts between 18 and 30 years. . The formula for permanent human teeth on one side of the jaw is:

in total 32. In dental practice, they use a more convenient formula with the designation of teeth in numerical order, starting from the first incisor and ending with the last (third) large molar: 1, 2 (incisors), 3 (canine), 4, 5 (small molars) , b,7,8 (major molars).

Vessels and nerves of teeth: The arteries of the teeth of the upper jaw originate from a. maxillaris; The posterior teeth of the maxilla are vascularized from the aa. alveolares superiores posteriores, anterior - from aa. alveolares superiores anteriores (from a. infraorbitalis). All teeth of the lower jaw receive blood from a. alveolaris inferior. Each alveolar artery sends: 1) branches to the teeth themselves - rami dentales, 2) branches to the periosteum of the alveoli, rami alveolaris and 3) branches to adjacent areas of the gums - rami gingivales. The outflow of blood occurs into the veins of the same name, flowing into v. facialis. The outflow of lymph occurs in the nodi lymphatici submandibulares, submentals et cervicales profundi. Innervation of the upper teeth is carried out by nn. alveolares superiores (from the II branch of n. trigeminus). Among them there are nn. alveolares superiores anteriores, medii et posteriores, forming the plexus dental is superior. The nerves of the lower teeth begin from the plexus dentalis inferior (from the n. alveolaris inferior from the third branch of the n. trigeminus).

- [de], dentin, pl. no, husband (from Lat. dentes teeth) (med.). Bone substance of the tooth. Ushakov's explanatory dictionary. D.N. Ushakov. 1935 1940 ... Ushakov's Explanatory Dictionary

CEMENTOMA- CEMENTOMA, a neoplasm built from tissue similar to the cement of the roots of teeth, and therefore belongs to the section of odontogenic tumors (see). In the literature, C. are considered as odontoma (see) with unilateral development: while the elements... ...

CARIES- CARIES. Content. Etiology and pathogenesis; without S. teeth........zzz Pathological anatomy of S. teeth......342 Klinina S. teeth............ 344 Statistics of dental teeth..................345 Therapy and prevention of dental teeth......347 Caries (from Latin ... ... Great Medical Encyclopedia

DENTAL CYSTS- DENTAL CYSTS, cavity formations located in the thickness of the alveolar processes, and partly in the body of the jaw bones, and etiologically associated with tooth decay. They have a connective tissue wall lined on the cavity side with a layer of epithelium.... ... Great Medical Encyclopedia

PERIDENTITIS- (periodontitis, paradentitis), inflammation of the periodontium (pericementum, root membrane). The tissues surrounding the tooth are connected to each other anatomically and physiologically and form a single biological system; therefore, the inflammatory processes that have arisen... ... Great Medical Encyclopedia

- (French email). 1) enamel, a glassy colorless mass, painted in various colors and transferred to metal objects for decoration. 2) white glaze, which covers the inside of cast iron and iron dishes. Dictionary of foreign words,... ... Dictionary of foreign words of the Russian language

ODONTOMA- (odontoma), a tumor that is a conglomerate of various soft and hard dental tissues. O. are localized primarily in the area of ​​large molars, most often on the lower jaw according to the position of the wisdom tooth, and are located ... Great Medical Encyclopedia

I Osteomyelitis Osteomyelitis (osteomyelitis, Greek osteon bone + myelos bone marrow + itis) inflammation of the bone marrow, usually spreading to the spongy and compact substance of the bone and periosteum. Classification. Based on etiology... Medical encyclopedia

The skinks, which form a large family, of 25 genera and 375 species*, are as varied in form as the American monitor lizards and the belt-tailed lizards: they represent, as is usually expressed, gradual transitions from lizard to ... ... Animal life

I Spine Spine (columna vertebralis; synonym vertebral column). It is an axial skeleton, consists of 32 33 vertebrae (7 cervical, 12 thoracic, 5 lumbar, 5 sacral, connected to the sacrum, and 3 4 coccygeal), between which... ... Medical encyclopedia

We have prepared an interactive map of the structure and a detailed description of all 23 sections of the tooth. Click on the corresponding number and you will receive all the necessary information. Using the diagram, it will be very easy to study all the features of the tooth structure.

The structure of human teeth

Crown

Crown ( lat. corona dentis) - the part of the tooth protruding above the gum. The crown is covered with enamel - hard tissue, 95% consisting of inorganic substances and subject to the most powerful mechanical stress.

There is a cavity in the crown - dentin (hard tissue 2-6 mm thick) comes closer to the surface, then pulp, filling both part of the crown and the root part of the tooth. The pulp contains blood vessels and nerves. Cleaning and removal of dental deposits are carried out specifically from the crowns of teeth.

Tooth neck

Cervix ( lat. collum dentis) the part of the tooth between the crown and root, covered by the gum.

Roots

Root ( lat. radix dentis) part of the tooth located in the dental alveolus.

Fissure

On the chewing surface of the back teeth, between the cusps there are grooves and grooves - fissures. The fissures can be narrow and very deep. The relief of the fissures is individual for each of us, but dental plaque gets stuck in the fissures of everyone.

It is almost impossible to clean the fissures with a toothbrush. Bacteria in the oral cavity, processing plaque, form acid, which dissolves tissue, forming caries. Even good oral hygiene is sometimes not enough. In this regard, it has been successfully used all over the world for 20 years.

Enamel

Tooth enamel (or simply enamel, lat. enamelum) - the outer protective shell of the coronal part.

Enamel is the hardest tissue in the human body, which is explained by the high content of inorganic substances - up to 97%. There is less water in tooth enamel than in other organs, 2-3%.

Hardness reaches 397.6 kg/mm² (250-800 Vickers). The thickness of the enamel layer differs in different areas of the crown part and can reach 2.0 mm, and disappears at the neck of the tooth.

Proper care of tooth enamel is one of the key aspects of human personal hygiene.

Dentine

Dentin (dentinum, LNH; lat. dens, dentis- tooth) is the hard tissue of the tooth, constituting its main part. The coronal part is covered with enamel, the root part of the dentin is covered with cement. Consists of 72% inorganic substances and 28% organic substances. Consists mainly of hydroxyapatite (70% by weight), organic material (20%) and water (10%), permeated with dentinal tubules and collagen fibers.

Serves as the foundation of the tooth and supports tooth enamel. The thickness of the dentin layer ranges from 2 to 6 mm. Dentin hardness reaches 58.9 kgf/mm².

There are peripulpal (internal) and mantle (external) dentin. In peripulpal dentin, collagen fibers are located predominantly condensally and are called Ebner fibers. In mantle dentin, collagen fibers are arranged radially and are called Korff fibers.

Dentin is divided into primary, secondary (replacement) and tertiary (irregular).

Primary dentin is formed during the development of the tooth, before its eruption. Secondary (replacement) dentin is formed throughout a person’s life. It differs from the primary by a slower pace of development, a less systemic arrangement of dentinal tubules, a larger number of erythroglobular spaces, a larger amount of organic substances, higher permeability and less mineralization. Tertiary dentin (irregular) is formed during tooth trauma, preparation, caries and other pathological processes, as a response to external irritation.

Dental pulp

Pulp ( lat. pulpis dentis) - loose fibrous connective tissue that fills the tooth cavity, with a large number of nerve endings, blood and lymphatic vessels.

Along the periphery of the pulp, odontoblasts are located in several layers, the processes of which are located in the dentinal tubules throughout the entire thickness of the dentin, performing a trophic function. The processes of odontoblasts include nerve formations that conduct pain sensations during mechanical, physical and chemical influences on dentin.

Blood circulation and innervation of the pulp are carried out thanks to dental arterioles and venules, the nerve branches of the corresponding arteries and nerves of the jaws. Penetrating into the dental cavity through the apical opening of the root canal, the neurovascular bundle breaks up into smaller branches of capillaries and nerves.

The pulp helps stimulate regenerative processes, which manifest themselves in the formation of replacement dentin during the carious process. In addition, the pulp is a biological barrier that prevents the penetration of microorganisms from the carious cavity through the root canal beyond the tooth into the periodontium.

The nerve formations of the pulp regulate the nutrition of the tooth, as well as the perception of various irritations, including pain. The narrow apical foramen and the abundance of vessels and nerve formations contribute to a rapid increase in inflammatory edema in acute pulpitis and compression of the nerve formations by the edema, which causes severe pain.

Tooth cavity

(lat. cavitas dentis) The space inside formed by the cavity of the crown and root canals. This cavity is filled with pulp.

Cavity of the tooth crown

(lat. cavitas coronae) Part of the tooth cavity located under the crown and repeating its internal contours.

Tooth root canals

Root canal ( lat. canalis radicis dentis) - represents the anatomical space inside the tooth root. This natural space within the coronal part of the tooth consists of a pulp chamber, which is connected by one or more main canals, as well as more complex anatomical branches that can connect the root canals to each other or to the surface of the tooth root.

Nerve

(lat. nervae) Neuronal processes passing through the apex of the tooth and filling its pulp. The nerves regulate the nutrition of the tooth and conduct pain impulses.

Arteries

(lat. arteriae) Blood vessels through which blood from the heart flows to all other organs, in this case to the pulp. Arteries nourish dental tissues.

Vienna

(lat. venae) Blood vessels that carry blood from organs back to the heart. The veins enter the canals and penetrate the pulp.

Cement

Cement ( lat. - cementum) - specific bone tissue covering the root and neck of the tooth. Serves to firmly secure the tooth in the bone alveolus. Cement consists of 68-70% inorganic components and 30-32% organic substances.

Cementum is divided into acellular (primary) and cellular (secondary).

Primary cement is adjacent to the dentin and covers the lateral surfaces of the root.

Secondary cement covers the apical third of the root and the bifurcation area of ​​multi-rooted teeth.

Root tips

(lat. apex radicis dentis) The lowest points of the teeth, located on their roots. At the tops there are openings through which nerve and vascular fibers pass.

Apical foramina

(lat. foramen apices dentis) Places of entry of vascular and nerve plexuses into the dental canals. The apical foramina are located at the apex of the tooth roots.

Alveolus (alveolar socket)

(alveolar socket) ( lat. alveolus dentalis) A notch in the jawbone into which the roots enter. The walls of the alveoli form strong bone plates impregnated with mineral salts and organic substances.

Alveolar neurovascular bundle

(lat. aa., vv. et nn alveolares) A plexus of blood vessels and nerve processes passing under the alveolus of the tooth. The alveolar neurovascular bundle is enclosed in an elastic tube.

Periodontium

Periodontium ( lat. Periodontium) - a complex of tissues located in the slit-like space between the cement of the tooth root and the alveolar plate. Its average width is 0.20-0.25 mm. The narrowest section of the periodontium is located in the middle part of the tooth root, and in the apical and marginal sections its width is slightly greater.

The development of periodontal tissue is closely related to embryogenesis and teething. The process begins in parallel with the formation of the root. The growth of periodontal fibers occurs both from the side of the root cement and from the side of the alveolar bone, towards each other. From the very beginning of their development, the fibers have an oblique course and are located at an angle to the tissues of the alveoli and cementum. The final development of the periodontal complex occurs after tooth eruption. At the same time, the periodontal tissues themselves are involved in this process.

It should be noted that, despite the mesodermal origin of the constituent components of the periodontium, the ectodermal epithelial root sheath takes part in its normal formation.

Gingival grooves

(lat. sulcus gingivalis) Gaps that form where the tooth crown meets the gums. The gingival grooves run along the line between the free and attached parts of the gum.

Gum

Gums ( lat. Gingiva) is a mucous membrane covering the alveolar process of the upper jaw and the alveolar part of the lower jaw and covering the teeth in the cervical area. From a clinical and physiological point of view, the gums are divided into interdental (gingival) papilla, marginal gum or gingival margin (free part), alveolar gum (attached part), mobile gum.

Histologically, the gum consists of stratified squamous epithelium and the lamina propria. There are oral epithelium, junctional epithelium, and sulcal epithelium. The epithelium of the interdental papillae and attached gingiva is thicker and can become keratinized. In this layer there are distinguished spinous, granular and horny layers. The basal layer consists of cylindrical cells, the spinous layer consists of polygonal cells, the granular layer consists of flattened cells, and the stratum corneum is represented by several rows of completely keratinized and nucleated cells that are constantly exfoliated.

Mucous papillae

(lat. papilla gingivalis) Fragments of gums located at their elevation in the area between adjacent teeth. The gingival papillae are in contact with the surface of the dental crowns.

Jaws

(lat. maxilla - upper jaw, mandibula - lower jaw) Bony structures that form the basis of the face and the largest bones of the skull. The jaws form the mouth opening and determine the shape of the face.

Dental anatomy is considered one of the most complex components of the human body; many scientific works are devoted to the structure of the oral cavity, but some aspects have not yet been thoroughly studied. For example, why do some people grow wisdom teeth while others don’t? Or why some of us suffer from toothache more often than others. Find more detailed information about individual structural features, possible pathologies and anomalies in the development of teeth on the pages of our website.