Long fangs in humans mean. How teeth and character of a person are connected. Root structure: pulp and periodontium

There are so many animals on the planet Earth. And toothy, and eared, and tongued animals - in one word, the animal world of the planet is very diverse. By the number and shape of teeth, you can characterize the animal and understand what it eats.

In fact, animals need teeth not only to chew food, but also to scare away predators. Some animals use their teeth in everyday life, for example, for sawing, digging and navigating difficult routes. Today's article will tell you about the most toothy animals on the planet.

The ten most toothy creatures are opened by a dwarf armadillo. This mammal lives in North and Central America. Animals have been living on planet Earth for a very long time, and they appeared back in the days of the dinosaurs. In addition, animals are also famous for their teeth. Inside one species alone, there can be from 28 to 40 teeth, and if the armadillo is gigantic, then the number of teeth can reach 100.

This feature is characteristic only of battleships. Interestingly, teeth differ not only within a certain species, but also in different individuals. The teeth of the dwarf armadillo grow constantly, but by themselves they are small in size, they do not have caries and enamel, and the shape of all teeth is the same - cylindrical.

This small animal appeared on the planet only at the very end of the Cretaceous period and has not changed much since then. The common possum is a small marsupial mammal with an archaic dental formula, which speaks of the primitiveness of these animals.

Possums have 5 incisors on the upper jaw, and 4 incisors on the lower jaw. The canines and molars of opossums are very well developed. The total number of teeth in common possums is 50.

This anteater is also called nambat. Outwardly, the animal is very similar to an ordinary squirrel, but it belongs to the family of marsupial anteaters. Nambit has weak, asymmetrical and small teeth, the total number of which is 50-52 teeth. These teeth help the anteater to pierce only the shells of some insects, which are its main food.

This large mammal lives in the waters and is the only member of its family. The sperm whale has 60 teeth, of which 20-26 pairs are located on the lower jaw. When the mouth is closed, each tooth is inserted into a special notch located in the upper jaw.

In one of the British museums, you can see a huge jaw, the length of which reaches 5 meters, and its owner was a 27-meter sperm whale. Today it is no longer possible to meet such giant sperm whales, since in the process of evolution they have become much smaller. To calculate the age of the sperm whale, you need to count the number of layers in the dentin of the sperm whale's tooth.

Undoubtedly, this is the most toothy reptile that exists today. In the mouth of this terrible predator there are about 80 incredibly sharp teeth. As soon as old teeth start to wear out, new ones appear in their place. It is interesting that it is by the teeth that you can distinguish an alligator from a crocodile. If the mouth of an alligator is closed, its teeth are not visible, while in a crocodile, even with a closed mouth, the fangs located on the lower jaw are clearly visible.

Despite the fact that this dolphin is quite peaceful, it possesses a huge number of teeth - 200-210, which makes it the record holder among all representatives of toothed whales. If we compare the common dolphin and the bottlenose dolphin, then the second has only 100 teeth.

4 Indian leech

This leech is considered the most toothy among all representatives of the species of annelids, to which it belongs. The Indian leech has as many as three jaws, each of which has 70 to 100 teeth. Thus, the total number of teeth in the leech is 350.

This type of shark is very rare, and so far scientists have not met a single old individual. This dangerous predator has 2 to 3 thousand very sharp teeth in its mouth. All teeth are located in several rows, however, only the first two rows of teeth are active, the rest are considered spare. Throughout their life, these sharks grow teeth, so new ones "come" in place of lost teeth or already worn out ones. Interestingly, the gray shark can even feed on crustaceans and bony fish, as its teeth are covered with special enamel.

2. Snails from the class of gastropods

These small and sluggish creatures rank second among the most toothy animals. On the tongue of the snails, there are 135 rows, each of which has 100-105 teeth. Thus, the total number of teeth is equal to 14 thousand. Though small, but what a toothy monster.

1. Large roadside slug

And here is the record holder for the number of teeth. The slug lives only on land, and its food does not include flesh. There are about 30 thousand teeth on the tongue of this baby. Gastropods need teeth to eat berries, fruits and leaves, in which the slug makes huge holes.

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Q: The man has fangs! It means from a predator.

A: According to nutritionists, its internal structure is more similar to herbivores than to predators. It has ten times less acidic gastric juice than carnivores, lacks the sharp incisors necessary for tearing meat, and has flat molars designed for longer digestion of food.

Man has no fangs, but only vestiges of fangs. The length of the gastrointestinal tract in humans is like that of a cow: eight times the length of the body, so the toxins released during the decomposition of eaten meat remain in the body for a very long time, poisoning it and making it difficult for the kidneys to function.

Q: I am a predator

A: You identify with a predator, although the biological characteristics of a person - the structure of the teeth, the length of the intestines, the temperature of the blood - indicate that a person is not a predator. Well, your right! Why don't you take the relationship that is characteristic of the spider world as the image: after all, the male is devoured by the female immediately after fertilization.

Physiologically, humans are much closer to herbivorous animals such as monkeys, elephants and cows than to carnivores such as dogs, tigers and leopards. Let's say predators never sweat; their heat exchange occurs through the regulators of the respiratory rate and protruding tongue. Vegetarian animals have sweat glands for this purpose, through which various harmful substances leave the body.

Predators have long and sharp teeth in order to keep and kill prey; herbivores have short teeth and no claws.

The saliva of predators does not contain amylase and therefore is incapable of preliminary decomposition of starches. The glands of carnivores produce large amounts of hydrochloric acid for the digestion of bones. The jaws of predators have a limited degree of mobility only up and down, while in herbivores they move in a horizontal plane to chew food.

Predators lap up liquid, as, for example, a cat herbivores suck it through their teeth. There are many such illustrations, and each of them shows the human body corresponds to the vegetarian model. Purely physiologically, people are not adapted to a meat diet.

Q: Vegetarian intestines are longer.

A: All herbivores have longer intestines than carnivores because plant foods take longer to process than protein foods.

Q: Eating meat is natural. Our body is programmed for this.

A: Human physiology is such that vegetarianism is more suitable for him. Predators have long, curved fangs and claws, and a short digestive tract. We have no claws, we have flat flexible nails, and our teeth are much more like those of orangutans and gorillas that do not eat meat.

Our small teeth are more suited to chewing fruit than tearing apart meat fibers. Eating meat is dangerous to health, because of this, cardiovascular, oncological and other diseases can occur.

Q: Why didn't I know all this before?

A: Now you know.

Teeth have become an important evolutionary acquisition, with their appearance, the diet of animals has become more diverse. And yet it has never been the same for different groups of living beings. Depending on this, the teeth also differ. By examining the teeth of a fossil animal, paleobiologists can tell what it ate, because the differences between the teeth of carnivores and herbivores were the same in ancient times as they are now.

Tooth structure

The teeth of any animal are covered with enamel - a special tissue, 97% composed of inorganic substances. Thanks to this, enamel is the hardest tissue in the body and perfectly protects the teeth. But even this hard tissue can be destroyed by some chemicals.

There are especially many such substances in plant foods. In order for an animal that eats such food, the enamel layer to survive, it must be very powerful, and the teeth of herbivores are distinguished by just such a feature. For predators, the danger of destroying the enamel is not so great, so there is no need for a thick layer. In carnivores, the enamel layer is much thinner than in herbivores.

However, even a thick layer of enamel does not save the teeth of herbivores from abrasion. Animals would lose their teeth early and die of hunger if they ate their molars, which bear the main load, not during the whole period. Enamel could interfere with the growth of teeth, so the molars of herbivores are covered with it only on the sides, and on top, where the tooth is constantly growing, there is no enamel.

Differentiation of teeth

In the course of evolution, teeth have acquired different shapes depending on the function they perform. Four varieties stand out: incisors, canines, premolars (molars) and molars (large molars).

The incisors are located in the front of the jaws. Their purpose is to gnaw or cut food. They are needed in any way of feeding, so all mammals have incisors, but still they play a more important role in herbivores.

In predators, the incisors are short and pointed. In herbivores, these teeth are very diverse. In lagomorphs in rodents, the incisors are long, in the form of chisels, and in ruminants there are only lower incisors, and the upper ones do not, because these animals do not gnaw anything, they only nibble the grass. The most interesting transformation was undergone by the incisors of elephants - they turned into tusks.

Fangs can be "cutting and stabbing tools". They are designed to tear off pieces of food. Most often this has to be done with meat, therefore, canines in predators are more developed than in herbivores. The fangs of predators are rather long and sharp, while in herbivores they either resemble incisors in shape, or are completely absent.

The molars (molars and premolars) are used to chew food. Predators chew food very poorly, so they have fewer molars than herbivores. In some herbivores (for example, in cows and horses), the molars are separated from the other teeth by a diastema - a disproportionately large gap. Predators also have diastemas, but they are located in other places: in front of the upper canines and behind the lower ones. Thanks to this, the predator can tightly close its teeth, capturing prey.

It is easy to see that in terms of the structure of the teeth, humans cannot be classified as either predators or herbivores. Differentiation of teeth in humans is not as pronounced as in other animals, all teeth are developed approximately equally. This suggests that man is an omnivore.

Health

The first thing we often pay attention to when looking at a person is his smile, and a person with healthy teeth usually immediately makes a pleasant first impression. An adult has an average of 28 to 33 teeth, depending on the presence or absence of wisdom teeth.

Teeth play not only an aesthetic role, but also help in grinding food for better digestion. But besides the fact that they need to be cleaned, we know little about this anatomical feature. Here are some interesting facts about our teeth.

1. Some babies are born with teeth

About one in 2,000 babies is born with prenatal teeth - teeth that erupt before birth. Typically, these teeth grow on the lower gum and have weak roots. Often these teeth are removed so that they do not interfere with breastfeeding or lead to accidental ingestion. In some cases, they may indicate the presence of certain medical problems, and in ancient physiognomy they were associated with evil forces. According to some reports, Julius Caesar and Napoleon were born with teeth.

2. Not all people lose milk teeth

The loss of baby teeth is a natural stage in our life. Usually, by the age of 3, children already have the entire set of 20 temporary teeth, which then loosen and fall out, after which permanent teeth begin to erupt at the age of 5-6 years. This process ends in early adolescence. But there are cases when a person does not grow permanent teeth, which is often associated with a family predisposition, he has milk teeth.

3. Some people have too many teeth

About 2 percent of people have hyperdontia, in which a person grows extra supernumerary teeth. Many of these teeth remain hidden under the gum, but sometimes they erupt and start crowding out other teeth. Very rarely, a person loses a permanent set of teeth at an older age and a different set grows. Everyone else will need dentures.

4. The tumor can also grow teeth

With teratoma - a tumor of germ cells, which is often found in the ovaries, testes and sacrococcygeal region, teeth, as well as hair, eyes, hands and other limbs can be found in the tumor tissues. Fortunately, these tumors are most often benign and can be surgically removed.

5. The tooth can also be seen

In 2000, a woman in the United States underwent a unique operation. Sharon Thornton lost her eyesight due to Stevens-Johnson syndrome, in which cells on the surface of the eye are destroyed. Doctors offered to restore the woman's eyesight with the help of ... a tooth. Her canine tooth was removed, an artificial lens was inserted and implanted in her left eye. A day later, the blind woman was able to see the world again.

6. Not all countries consider straight teeth beautiful

Do you think that straight white teeth are a universally recognized ideal of beauty? Crooked teeth called "yaeba" have become very popular in Japan. At the same time, many Japanese women deliberately curl their straight teeth, accentuating their canines, in order to look younger and prettier.

7. In the future, we will not have wisdom teeth

Third molars, or wisdom teeth, helped our larger-jawed ancestors to grind roots, nuts, and leaves. But now about 35 percent of people are born without wisdom teeth. For the rest, dentists recommend removing them, since our oral cavity is too small for them. When our body no longer needs some organs or parts, they become rudimentary and eventually disappear. According to scientists, future generations will not have an appendix, wisdom teeth, and possibly even little toes.

8. For teeth, raisins are more harmful than chocolate

Not all sweets are equally bad for your teeth. Sugar from a variety of foods is a breeding ground for bacteria that create acid that can destroy teeth. Foods that get stuck in the teeth, including bread, chips, and dried fruits, are often more harmful than those that dissolve quickly (chocolate, gummies). At the same time, it is better to eat sweets right away than to snack many times during the day, constantly feeding the bacteria.

Tooth enamel is the hardest tissue in the human body.

A person has an average of 32 teeth, including 8 incisors, 4 canines, 12 molars (including 4 wisdom teeth) and 8 small molars. Each of them performs its own functions. Incisors help bite off pieces of food, canines hold and tear food, and molars grind it.

No two dentitions are alike. They are almost as unique as fingerprints.

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

Upper canines. The vestibular surface of the crown is diamond-shaped (Fig. 1). The incisal edge consists of two halves that converge at an angle and form a tooth. The angle of the tooth is often slightly more than straight, it can be obtuse or sharp. Prong forms main canine tubercle... The tubercle is not located in the middle, but somewhat mesially shifted. The tubercle portions of the incisal edge are also sharpened, so that the incisal edge resembles a spearhead. The distal part of the margin is longer and steeper than the mesial part. On the distal edge of the incisal edge, it is sometimes found intermediate tubercle... The angle formed by the mesial incisal edge and the mesial crown edge is further from the neck than the angle between the distal incisal edge and the distal crown edge. The distal angle is more often obtuse and rounded; the mesial angle approaches the straight one and has a distinct apex. Thus, the sign of the crown angle on the upper canine is well pronounced.

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 margins, small edge combs... Between the middle ridge and the marginal ridges, there are two small grooves corresponding to shallow incisions on the mesial and distal parts of the incisal 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 middle one. The lateral edges of the crown approach the neck.

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

When considering the contact surfaces of the canine crown, attention is drawn to the large thickness of the crown base in the vestibulo-lingual direction. The contour of the vestibular surface is arcuate, convex, and the lingual 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 arch on the lateral surfaces of the tooth is open to the root, and on the vestibular and lingual surfaces - to the incisal edge.

The root of the upper canine is long, compressed in the mesiodistal direction. The vestibular contour of the root is usually convex, less often flat, the lingual - convex in the cervical and middle thirds and concave in the apical third. Longitudinal grooves are noticeable on the lateral surfaces of the root, 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 sharpened 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 depression of the cavity. Split root canals are encountered.

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

The lower canines are smaller, with a narrower crown and a more compressed root in the transverse direction (Fig. 2). Their incisal 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, obtuse or straight, the distal is always obtuse and, as a rule, rounded. The median ridge and marginal ridges are less pronounced. The mesial edge of the crown runs almost vertically and continues into the same root contour. The distal margin 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; c - lingual surface; d - vestibulo-lingual cut; e - mesiodistal cut; e - cutting edge; 1, 2, 3 - the shape of the cross sections at the level of the crown, middle and upper third of the root, respectively

On the lingual surface of the crown, the marginal ridges are well developed. There are spatulate lower incisors. 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-visible marginal ridges, 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 vertical 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 from the lingual surface are slightly convex or straight. The root is strongly compressed in the mesiodistal direction. Well-defined longitudinal grooves 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. Bifurcation of root canals 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 crown base is 5-6 mm, the vestibulo-lingual 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 antagonist canines are closed, the distal part of the incisal edge of the lower canine is in contact with the mesial part of the upper crown. Sometimes there are extra fangs(usually upper) that erupt outside the dental arch (or remain in the jaw). The canines rise slightly above the rest of the teeth and protrude from the row in the vestibular direction. When crowding, the canines may be in an irregular position, usually moving vestibularly. Trama between canines and first premolars is very common. Almost as often, there is a trime between the canines and the lateral incisors.

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