Healthy and beautiful teeth are an adornment of any person. Pink gums, an even bite and a snow-white smile indicate that a person has excellent health and, in general, is considered a sign of his success. Why is this given to teeth? great attention and why did it happen?

General concepts of teeth and their classification

Teeth are special bone formations that carry out the primary mechanical processing of food. People have long been accustomed to eat rather hard food - meat, cereals, fruits of plants. This food needs considerable effort to process, and therefore healthy teeth have always been considered an indicator that a person eats varied and well.

To begin with, what you need to know about teeth - these are the only organs in the human body that not recoverable. Both their apparent reliability and fundamentality are quickly violated bad habits and poor care.

And if milk, primary teeth are fragile precisely because of their temporary purpose, then the molars are given to a person until the end of life. In general, the entire dentition in humans is divided into the following types:

  • fangs;
  • incisors (lateral and central, they are also called lateral and medial);
  • molars or large molars (this also includes the upper and lower wisdom teeth that grow in a person at a mature or young age);
  • premolars or small molars.

As a rule, the location of the dentition on the upper and lower jaws is recorded using the so-called dental formula. For molars and milk teeth, this formula differs only in that the molars are most often indicated using Arabic numerals, and milk teeth - in Latin.

For an average adult, the dental formula looks something like this: 87654321 | 12345678. The teeth are indicated by numbers - any healthy person must have one canine, 2 incisors, 3 molars on each side, 2 premolars on the upper and lower jaws. As a result total it turns out - 32 pieces.

For babies who have not yet changed temporary teeth, this formula looks different, since there can be only teeth about 20 pieces. As a rule, temporary teeth erupt by 2–3 years, and by 9–12 they are completely replaced by permanent ones. However, not all people can boast of having all 32 teeth sprouted.

Since wisdom teeth or third molars may appear in adulthood, or they can completely be in their infancy all their lives, and in this case, in a person in the oral cavity will be 28 teeth. Moreover, the structure of the lower and upper jaw has certain differences.

Anatomical structure

Anatomy human tooth suggests that it is conditionally divided into 3 parts: root, neck and crown. The crown is called the raised part above the gum, it is covered with enamel - the strongest tissue that protects the dentary from negative impact acids and bacteria. There are several types of crown surfaces:

The neck is the part that is between root and crown connecting them, covered with cement and closed by the edges of the gum. The root is the part with which the tooth is attached in its hole. Taking into account the classification type, the root can be with one or more processes.

Histology

The histological structure of all teeth is exactly the same, but all of them have different shape according to the specific function performed.

Enamel. This durable fabric, which consists of 95% different salts like zinc, magnesium, copper, strontium, fluorine and iron. And 5% are substances such as carbohydrates, lipids, proteins. In addition, the enamel contains a liquid that is involved in physiological processes.

At the same time, enamel also has outer shell, which is called the cuticle, it covers the chewing surface, but over time, the cuticle tends to wear off and become thinner.

basis bone tissue tooth is dentin is a collection of minerals surrounding the root canal and the entire dental cavity. The dentine tissue contains a large number of the smallest channels through which metabolic processes take place and also through the channels nerve impulses are transmitted.

Root structure: pulp and periodontium

The cavity inside the tooth is formed by the pulp - this is a loose and soft tissue, permeated through with nerve endings, as well as lymphatic and blood vessels.

The structure of the roots looks like this. The root is in a special hole - the alveolus, in the jaw bone. The root, like the crown, consists of a mineral tissue - dentin, covered on the outside with cement.

Root ends with an apex, through its opening pass blood vessels that feed the dentary. The number of roots can vary, taking into account the functional purpose of the teeth, from 1 root in the incisors, to 5 in the chewing ones.

Periodontium is connective tissue, which fills the gap between the socket of the jaw and the tooth root. The fibers of the tissue, on the one hand, are woven into the cement of the root, and on the other hand, into the tissue of the jaw bone, due to this, the tooth is firmly attached. In addition, through the periodontal tissues, the nourishing elements of the blood vessels can enter the dental tissues.

Description of the dentition

Incisor teeth. The human jaw is symmetrical and includes the same number of teeth of each type. But there are certain anatomical features upper and lower jaw. Let's analyze them in more detail.

The incisors are the front teeth.. A person has eight of them - 4 from the bottom and 4 from the top. The incisors are needed to bite through food, to divide it into parts. The peculiarity of the structure of the incisors is that they have a flat crown in the form of a chisel, with rather sharp edges.

On anatomical sections, there are three tubercles, which are erased throughout life. Above the jaw two central incisors- in its group, the largest of all incisors. The lateral incisors are similar in shape to the central incisors, but smaller in size.

Remarkably, directly cutting edge the lateral incisor also has three tubercles, and often takes on a convex shape as a result of the development of the central tubercle. The incisor root takes the form of a cone, and is flat and single. Distinctive feature incisor - from the side of the tooth cavity are three pulp apices corresponding to the tubercles of the cutting edge.

The anatomy of the upper teeth is slightly different from the structure of the lower dentition, so everything is exactly the opposite on the lower jaw. Medium incisors are smaller unlike the lateral ones, they have a shorter and thinner root than the incisors on the sides. The outer surface of the incisor is slightly convex, while the inner surface is concave.

Incisor crown, side curved to the lips and very narrow. The cutting edge has 2 corners - in the center, sharper, and inside - more blunt. They have longitudinal grooves on the root.

Chewing teeth and fangs

The fangs are used to break food into smaller pieces. The anatomy of the canines is such that on inside there is a groove in the crown, it disproportionately divides the crown into 2 parts. The cutting edge of the fangs has one pronounced and developed tubercle, which makes the cone-shaped crown often look like the fangs of a predator.

The canine on the lower jaw is narrower in shape, the ends of the crown are concentrated in the medial tubercle. The canine root is flat, deviated inward and the longest, unlike the roots of other teeth. In man 2 canines on both jaws. Lateral incisors with fangs form an arc where the transition from incisors to chewing teeth begins in the corner.

Consider the structure of the small chewing tooth first, and after the large chewing tooth. Their main task is meticulous food processing. This function is performed by molars and premolars.

premolars

The first premolar (No. 4 in the dental formula) differs from the incisors and canines in its prismatic shape; there are convex surfaces on the crown. The surface has 2 tubercles - lingual and buccal, between them there are furrows.

The buccal tubercle is much larger than the lingual one. The root of the first premolar has flat shape, but already with a slight bifurcation into the lingual and buccal parts.

The second premolar is similar in structure to the first, but its buccal surface is much larger, and the root has a compressed anteroposterior direction and tapered shape. At the first lower premolar, the chewing surface is inclined towards the tongue.

The second premolar is larger than the first due to the fact that both tubercles are symmetrical and equally developed, and the depressions in the enamel between them look like a horseshoe. The root is the same as that of the first premolar. In a person in the dentition there are 8 premolars, four on each side (on the lower and upper jaws).

molars

In the upper jaw, the first molar is the largest. Its crown is similar to a rectangle, and the chewing surface is a diamond-shaped shape with 4 tubercles. This molar has three roots: one straight - the most powerful, and two buccal - flat, deflected in the posterior direction.

The first molars, during the closing of the jaws, rest against each other and form a "limiter"”, because of this, they undergo significant stress throughout a person’s life.

second molar has a smaller size. The roots are the same as those of the first molar. The structure completely coincides with the location of the premolars described above.

On the lower jaw, the first molar for chewing food has five tubercles. This molar two roots- front with two channels, rear - with one. In this case, the anterior root is larger than the posterior one. In the lower jaw, the second molar is similar in structure to the first. The number of molars in humans is the same as premolars.

The third molar is called wisdom tooth”, and in total a person has four of them in the dentition, two on each jaw. On the jaw from below, the third molar has many variations in the development of tubercles. As a rule, there are five of them. But, in general, in humans, the structure of the “wisdom tooth” is the same as the structure of the second molar, but the root usually resembles a very powerful and short trunk.

Baby teeth

Histological and anatomical structure The milk tooth is similar to the structure of the molar, however, there are certain differences:

In the end, I would like to note that, of course, the layout of the teeth in the jaw, their structure, closure have an individual character for each individual person. But the dentoalveolar apparatus of each person performs vital functions throughout life, therefore, over time, the dental structure changes.

We must not forget that in dentistry, many pathological processes appear in childhood, so you need to monitor the condition of the teeth since childhood. This will help you avoid problems in the future.

Despite the apparent simplicity, teeth are quite fragile and complex system, with a multilayer structure, where each layer and element has its specific purpose, as well as certain properties. And the fact that the change of teeth takes place only once during a lifetime makes the structure of the human jaw different from the anatomy of the jaw of other representatives of the fauna.

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Fangs (dentes canini). In places of the greatest bending of the dental arches, there are 4 canines, sometimes they are called angular teeth. Fangs are relatively large teeth with a simple one-cusp crown and one powerful long root.

Upper fangs. The vestibular surface of the crown is diamond-shaped (Fig. 1). The cutting edge consists of two halves converging at an angle and forming a tooth. The angle of the tooth is often a little more than a straight one, it can be blunt or sharp. prong shapes main tubercle of the canine. The tubercle is not located in the middle, but is somewhat shifted mesially. The parts of the cutting edge that form the tubercle are also pointed, and therefore the cutting edge is similar to the tip of a spear. The distal part of the margin is longer and steeper than the mesial. On the distal edge of the incisal edge is sometimes found intermediate tubercle. The angle formed by the mesial part of the incisal edge and the mesial edge of the crown is located further from the neck than the angle between the distal part of the incisal edge and the distal edge of the crown. The distal angle is often obtuse and rounded, the mesial angle approaches a straight line and has a clear apex. Thus, the sign of the crown angle on the upper canine is well expressed.

Rice. 1. Upper canine, right:

A wide ridge extends from the main tubercle along the vestibular surface of the tooth to the neck. On the distal and mesial edges, small marginal scallops. Between the middle roller and the marginal scallops there are two small grooves corresponding to shallow cuts on the mesial and distal parts of the cutting edge. The notch between the main tubercle and the mesial angle of the crown is more developed. A short ridge originates from the accessory tubercle of the distal rib, merging with the median one. The lateral edges of the crown converge towards the neck.

On the lingual surface of the canine are clearly visible marginal scallops, sometimes strongly developed, spreading from the corners of the crown to lingual dental tubercle, which is usually well expressed. From this tubercle to the main tubercle of the cutting edge there is a well-defined median ridge; depressions are formed between it and the marginal scallops. The distal depression is larger than the mesial one. In some cases, there is a gap that cuts the lingual dental tubercle. Sometimes on the distal half of the lingual surface of the crown there are one or two small triangular pits, the angle of which is open to the cutting edge.

When considering the contact surfaces of the canine crown, attention is drawn to the large thickness of the base of the crown in the vestibulo-lingual direction. The contour of the vestibular surface is arcuate, convex, and the lingual one is concave, but less than that of the incisors. With a highly developed lingual dental tubercle, the contour of the lingual surface of the crown may even be slightly convex. The contour of the enamel-cement border is arcuate, and the arc on the lateral surfaces of the tooth is open to the root, and on the vestibular and lingual surfaces - to the cutting edge.

The root of the upper canine is long, compressed in the mesiodistal direction. The vestibular contour of the root is usually convex, rarely flat, lingual - convex in the cervical and middle thirds and concave in the apical third. On the lateral surfaces of the root, longitudinal grooves are noticeable, which are sometimes very strongly developed. Rarely, the root of the upper canine can split into two roots - vestibular and lingual. The roots of the upper canines on the alveolar process correspond to canine eminence (eminentia canina).

The cavity of the crown is pointed in the direction of the main tubercle, then gradually expands to the level of the corners of the crown, after which it narrows and passes into the root canal. In the direction of the lingual dental tubercle, there may be a deepening of the cavity. There are split root canals.

The height of the crown of the upper canine is 9.5-12.0 mm, the width is 7-8 mm, the vestibulo-lingual size of the neck of the tooth is 7.0-8.5 mm, the mesiodistal size is 5-6 mm; root length - 15-19 mm.

The lower canines are smaller, have a narrower crown, and have a more transversely compressed root (Fig. 2). Their cutting edge has a main tubercle, also displaced mesially. It is less pronounced than on the upper canines. The crown angles of the lower canines are also different: the mesial is better defined, blunt or straight, the distal is always blunt and usually rounded. The median ridge and marginal ridges are less distinct. The mesial edge of the crown runs almost vertically and continues into the same contour of the root. The distal edge with the contour of the root forms a noticeable bend. The root deviates distally.

Rice. 2. Lower canine, right:

a - vestibular surface; b - mesial surface; in - lingual surface; d - vestibular-lingual section; e - mesiodistal section; e - cutting edge; 1, 2, 3 - the shape of the transverse sections at the level of the crown, middle and upper third of the root, respectively

The marginal scallops are well developed on the lingual surface of the crown. The lower incisors are shovel-shaped. Lingual dental tubercle and the median ridge are less pronounced. The more developed the median ridge, the less pronounced the marginal ridges and vice versa. The lingual surface is often more or less flat, and with well-marked marginal scallops, it is concave. The teeth of the tubercle on the lingual surface are not formed.

When examining the lower canine from the lateral surface, it can be seen that the contour of the lingual surface is concave and more steep than on the upper canines. The contour of the vestibular surface has a more flattened bulge.

The contours of the root, both from the vestibular and lingual surfaces, are slightly convex or straight. The root is strongly compressed in the mesiodistal direction. Well-defined longitudinal furrows lie on the contact surfaces in the middle of the root. Often (10%), the root of the lower canines is divided into two, while both roots can be of equal length and thickness, or the vestibular root is thicker but shorter. The volume of the cavity of the lower canines is less. Root canal bifurcation is rare.

The height of the crown of the lower canines is 9-12 mm, the width is 6-7 mm, the mesiodistal diameter of the base of the crown is 5-6 mm, the vestibulo-lingual diameter is 7-8 mm; root length - 12.5-17.0 mm.

The upper and lower canines are stable in the dentition, there is no absence of canines. When the canines-antagonists are closed, the distal part of the cutting edge of the lower canine is in contact with the mesial part of the upper canine crown. Sometimes there are extra fangs(usually upper) that erupt outside the dental arch (or remain in the jaw). The fangs slightly rise above the rest of the teeth and protrude from the row in the vestibular direction. In crowding, the fangs may be misaligned, usually shifting vestibularly. Trema between canines and first premolars is very common. Almost as often there is a trem between the canines and the lateral incisors.

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

Once upon a time, physiognomists determined the character of a person by the teeth as follows.

The shape of the teeth and the character of a person

  • Small, sharp, rare teeth mean malice and cunning, large gaps between the teeth - dementia and lack of will.
  • Large strong teeth - courage, kindness, strength, long life.
  • Long teeth speak of malice, gluttony, long, sharp, protruding teeth - of insatiability, stinginess.
  • Straight teeth mean eloquence, irritability, uneven teeth - a tendency to think, small black teeth - lust.

In the Eastern tradition, they have long known how to determine the character of a person by the teeth. It is believed that the teeth should be straight, long, white and flat, without gaps. They should not protrude forward or bend back. Yellowish or dark teeth, especially small and short ones, occur in people with a dishonest character or when short life, the fate of such a person is difficult. In addition, it is important that the number of teeth is complete. If a person has much fewer teeth than expected, then his fate will turn out badly. If the teeth taper downward in shape, then this is a sign that the person is greedy or cruel. And if the narrow part of the tooth is upper, then this a kind person.

Let's continue the definition of character by teeth. Special attention turn on the two front incisors of the upper jaw. Ideally, they should be even, wide and long, then this speaks of strength, courage and a good career. And if such incisors are short, crooked and sharp, then the person is dishonest, one cannot rely on him.

What can be learned from the condition of a person's teeth

  • Determining character by teeth is not a complicated process. So, if all the teeth fit snugly together, are large, white - these are the teeth of a horse. They happen to people who are lucky and healthy.
  • If the two front teeth are larger than the rest and all the teeth are even and tight, these are pomegranate teeth. They talk about a successful marriage and wealth.
  • If the teeth do not fit snugly together, this indicates a changeable fate, such a person has an unstable income.
  • If the teeth are crooked, they are called "devil's teeth". The owners of such teeth can be vindictive and envious, they are very prudent by nature and always seek their own benefit.
  • If the teeth are too short, then the person is not rewarded with a great mind.
  • If the teeth protrude forward, then their owner will have to achieve well-being for a long time and most likely he will make a career away from home.
  • If the teeth are very long and the incisors are sharp and protrude downward, these are dog teeth. Often such people become the culprits of the misfortune of other people.
  • If the teeth are too wide, then the character of a person is open, honest, noble, but due to ingenuity, he often falls for deception.

Now you know how to determine the character of a person by the teeth.

What scientists just do not come up with to surprise ordinary people. And now they have found a connection between our teeth and our character. It would seem - where is the connection here, because we cannot influence our teeth (they grow as they want, and only then you can contact the dentist to fix our smile for us). You might think that our character changes with our teeth, or does it not? Whether this is true or not, judge for yourself by observing your teeth and your character.

So, let's start comparing:

1.Large incisors- the owners of such teeth are very sociable, talkative, love flattery, strive to be the first everywhere. Such people always want to be in the spotlight, they strive to grab everything at once, they love money and power. They can trust few people, only the most faithful and devoted friends. If you are friends with a person who has large incisors, you can be calm - they will not betray, they will always come to the rescue in any situation.

2.small teeth- if you have such teeth, then you are a cunning person who is prone to adventures and adventures. Scientists believe that such people always achieve their goal, whatever it may be. In addition, these people are very unusual and talented.

3.Characteristically pronounced protruding fangs- if you have just such fangs, then you are a very sexy, charming and attractive girl who has a crowd of fans. You always achieve your goal, and do this in such a way that no one will notice the trick and deceit on your part.

4.Large gap between upper front teeth is a sign of great energy and unpredictability. But your unpredictability and desire to shock often leads to misunderstanding on the part of others, which often causes conflicts and disputes.

5.Long upper incisors- your desire to joke often turns into incomprehensible "black humor", and your desire to save money - into greed. Such people can become good family men, and in the company they can joke (as it seems to them) merrily, although sometimes they do it really funny.

6.Crooked teeth- this is an indicator of good intuition, cunning, talent to get out of the most difficult situations. Such people have good connections which are often useful in life. But, if suddenly something doesn’t work out for such people, they can do such things that “the whole world will need to clear up”. There are quite a lot of loving people among the crooked teeth.

7.Beautiful straight teeth- This is an indicator that a person takes care of his teeth and often visits the dentist. But if you got your straight teeth from nature, this is a great happiness. The owners of such teeth value fidelity in relationships, do not tolerate deceit, love order and respect traditions. Their luck is not related to the saying "fools are lucky." Their luck is associated with diligence, a serious attitude to everything and responsibility.

8.Broken and decayed teeth- they say that their mistress (or owner) should go to the dentist. In addition, such teeth speak of irresponsibility, laziness, resourcefulness, if you are too lazy to go to the doctor, then you are too lazy to do anything at all, right? If you have such teeth, immediately consult a dentist, review your diet, start caring for your teeth, after all. To people with such teeth completely negative attitude from the side of others, therefore, they are also not particularly lucky with work.

Whatever your teeth are, don't forget to keep an eye on them so you don't end up with no teeth at all. As the saying goes folk wisdom: “The one who has 32 (or 28 without four wisdom teeth) healthy teeth laughs well!”