The structure of the human tooth: diagrams and history. How many primary and permanent teeth should a child and an adult have? The number of permanent teeth in an adult

Today we will tell you in detail about how many teeth people have, and also tell you about their structure, functions, types, etc.

General information

Teeth are bony formations located in oral cavity person. They are located in the form of 2 arcs (one above the other). If a person closes the lower one and together, then the teeth will close, separating the vestibule of the mouth from its own cavity. In this position, people develop a bite, which is studied by the science of orthodontics.

Healthy teeth are a pretty good indicator of the functioning of the whole organism. However, most people do not just want to show off their excellent physical condition, but also a beautiful and snow-white smile. We’ll look at what to do for this at the very end.

Shapes and main types of teeth

Before we tell you how many teeth people have, we should find out exactly how they differ in their shape and purpose. After all, each individual tooth performs exclusively its functions, namely capturing food, holding it in the mouth and chewing. It is also worth noting that they are directly involved in the correct pronunciation of sounds.

Incisors

These teeth are located in the very front of the dentition (4 on top and the same number on the bottom). They owe their name to the fact that they have a sharp cutting edge, with the help of which a person can easily bite off any food, including quite hard ones.

Fangs

On both sides of the incisors in humans there are cone-shaped teeth or so-called “fangs” (2 on top and the same number on the bottom). They are designed to tear off small pieces from a whole product. It should be noted that in humans these types of teeth are rather weakly developed than in carnivorous animals. This is due to the fact that people do not eat raw, rough and fibrous foods such as meat.

Small molars

In medical practice, such premolars. There are two tubercles on their chewing surface. As for the roots, there can be one or two. Small molars are necessary for humans to crush food, as well as for their further grinding. In addition, premolars can also be used for tearing food.

Large molars

The presented teeth, located both on the lower and on the upper jaw, are called molars. Unlike previous bone formations, they are larger in size and also have more than one root (the upper ones are three, and the lower ones are two). In addition, they have a chewing surface and special depressions called fissures. There are also four or five cusps at the top of the large molars. The main function of molars is to grind and grind food into a pulp before it is directly swallowed.

So how many molars does a person have? The number of premolars is four on top and the same number on the bottom. As for large molars, their number is similar to small ones.

Types of teeth

It should be noted that a person has two sets of teeth: temporary and permanent. In their functions and structure they are quite similar to each other. However, the temporary bone formations are much smaller in size and have a different shade (whitish-bluish). By the way, they are usually called “milk”.

They play a fairly important role in the development of primary and permanent teeth. After all, such formations, even in childhood, retain the necessary space for future incisors, canines, premolars and molars, and also guide their further growth. It is worth noting that the number of baby teeth in humans is only 20. As a rule, they begin to erupt at about 3-6 months and are completely out by 2.5 or 3 years.

Having found out how much a person has, we should move on to describing the constants. Usually they begin to appear by the age of 5-6 years and completely replace temporary ones at 12-14 years. The first molars grow in the free space behind the milk teeth. When the time comes, the roots of children's temporary teeth dissolve and subsequently fall out. As is known, such a process occurs in pairs and in a certain sequence.

Thus, the answer to the question of how many teeth a person changes may well be the number 20. After all, this is how many baby teeth fall out in small children, and later permanent incisors, fangs, etc. grow in their place.

Is 32 normal?

When you ask your dentist a question about how many teeth people have, you may hear a very clear answer: 32. This figure is made up of the following numbers:

• 8 incisors (4 of them are located on lower jaw and 4 - on the top);
• 4 fangs (2 at the top and the same number at the bottom);
• 8 premolars (4 below and 4 above);
• 12 molars (6 on the upper jaw and the same number on the lower jaw).

However, some people, having counted their teeth, are quite often indignant at the fact that they find 28 instead of 32. This is due to the fact that the molars, which grow by the age of 14, make up only 2 pairs on the lower and upper jaws, respectively. In other words, the number of large molars in healthy people there are exactly the same as small ones (that is, 8 pieces). "So where are the other 4?" - you ask. The fact is that the total number of teeth a person has is counted together with the so-called “wisdom” teeth. As a rule, such bone formations grow in people between the ages of 17 and 30. Moreover, they may never appear at all, making the number 32 not such a norm.

So how many wisdom teeth does a person have? Reply to asked question A simple mathematical calculation can help you:

32 (normal number of teeth) - 28 (permanent teeth that grow by age 14) = 4, 2 of which are located at the top and the same number at the bottom.

As was said just above, such bone formations may never grow at all. This fact is due to the fact that in the process of evolution, molars that are unnecessary for chewing are gradually reduced. According to statistics, only half of the population of our planet has a complete set of two arches on the lower and upper jaw.

Historical background and a look into the future

If the question of how many teeth people have was asked in the distant past, then a completely different number would have been asked, not 32. After all, our ancestors had as many as 44 bone formations in the oral cavity, that is, exactly 12 teeth more. Over time, several pairs of teeth disappeared on each side of the upper one.

According to experts, after several hundred years, people may also have reduced second and third molars, as well as lateral incisors. This is due to the fact that he increasingly eats exclusively soft and porridge-like dishes, the chewing of which does not require the above-mentioned bone formations. By the way, this may also cause people’s jaws to gradually become smaller. Of course, such evolutionary changes can be reversed. But in this case, additional stress should be given to the entire dental system. To do this, a person needs to eat more animal or rough plant foods.

Tooth structure

We found out how many teeth an adult has a little higher. But speaking about such bone formations, with the help of which people eat every day and supply their body with all the necessary substances, one cannot ignore their structure.

As you know, this element consists of three main components: crown, neck and root.

1. “Crown” is the visible part of the tooth, which is covered with enamel (the most solid in the human body), relatively resistant to destruction.

2. The neck is the part of the tooth embedded in the gum.

3. The root of any tooth is located directly in the jaw bone.

It is also worth noting that the bulk of the presented bone formations is formed by the so-called “dentin”, located under the enamel. This substance is quite durable. However, in terms of its resistance to damage and hardness, it is still inferior to the crown. As is known, dentin is penetrated by multiple channels containing processes of the cells of which it, in fact, consists.

As for the dental cavity, it includes nerve endings, as well as blood vessels. They deliver all the necessary nutrients to the living tissues of bone formations and remove their waste products.

Returning to the roots, it should be noted that they are completely covered with cement. This substance is quite similar to ordinary bone. It is to this part of the tooth that multiple fibers are attached, which hold it firmly in place (in the gum). However, there is still some mobility of such bone formations. Indeed, thanks to this, the likelihood that they will break while chewing solid food is significantly reduced.

Few people know, but inside all human teeth there is a cavity that extends into the root in the form of a canal, and ends with a small hole at the tops. As you know, this hollow place is filled with the so-called “pulp”. It is into it that nerve endings and various vessels penetrate through the jaws.

How to take care of your teeth?

If you want to keep all 32 teeth (or 28), then they must be carefully cared for. To do this, experts recommend cleaning them well in the evening and in the morning, and after each meal, be sure to rinse your mouth. Following the rules of personal hygiene will allow you to keep all your teeth until old age. But if for some reason your teeth hurt, you should immediately contact your dentist. By the way, it is recommended to visit it at least twice a year. After all, preventing caries and other problems with bone formations is less painful and cheaper than long and painful treatment.

It's simple - this is the only organ of the human body that cannot recover on its own.

Modern and ancient teeth

In the anatomy course, the definition of a tooth is given - it is ossified part of the mucosa shells designed for chewing food.

If we delve deeper into phylogenetics, then the “progenitor” of human teeth is considered fish scales located along the mouth. As they wear, teeth change - this is a mechanism inherent in nature.

In lower vertebrate representatives of the fauna, replacement occurs several times during the entire life cycle.

The human race is not so lucky; its bite changes only once - the milk teeth are replaced by permanent teeth.

Evolution has significantly changed the human jaw apparatus. U ancient man there were more than 36 teeth. And this was justified by the diet - hard raw food. To chew it, you had to work your jaw with force. Therefore, a massive jaw apparatus and chewing muscles were developed.

When our ancestors learned to make fire, they had the opportunity to process food. This made the diet softer and more easily digestible. Therefore, the anatomy of the jaw underwent transformation again - it became smaller. Homo sapiens' jaw no longer protruded forward. It has acquired a modern look.

The teeth of primitive people were not beautiful and did not form a radiant smile, but they were different strength and health. After all, they actively used them, chewing solid and rational food.

Anatomical development

The formation of teeth is a long process that begins in the womb and is completed by the age of 20 at best.

Dentists distinguish several periods of tooth development. The process has already begun in the second month of pregnancy.

Children have 20 baby teeth, an adult has 32. The first teeth are at six months, and by the age of 2.5 they are already present complete milk set. Outwardly, they are similar to permanent teeth, but there is a fundamental difference - thin enamel, large numbers organic matter, short, weak roots.

By the age of 6, the baby's bite begins to change. Besides, molars are erupting, which did not have dairy predecessors.

The process continues up to 14 years. And it ends only when the third and fourth teeth – “wise” teeth – erupt. You can wait for them until old age.

Structure

A tooth, as a separate element, includes identical parts. The structure of a human tooth in cross-section can be seen in the diagram:

1. Crown– visible part.
2. Root– in the recess of the jaw (alveolus). Attached by connective tissue made of collagen fibers. The apex has a noticeable opening penetrated by nerve endings and vascular network.
3. Neck– combines the root part with the visible part.

1. Enamel– hard covering fabric.
2. Dentine– the main layer of the tooth. Its cellular structure is similar to bone tissue, but is distinguished by its strength and high mineralization.
3. Pulp– central soft connective tissue, penetrated by the vascular network and nerve fibers.

Look visual video about the structure of teeth:

Milk teeth have the following features:

• smaller size;
• reduced degree of mineralization of layers;
• larger volume pulp;
• fuzzy bumps;
• more convex incisors;
• shortened and weak rhizomes.

With improper care of the primary occlusion, 80% of all adult pathologies develop precisely at an unconscious age. Careful hygiene of replacement teeth saves permanent teeth from many potential problems.

Types of teeth

Teeth differ in appearance and functions. Despite these differences, they have general mechanism of development and structure. The structure of the human jaw includes the upper and lower dentition (2 dental arches), each with 14-16 teeth. We have several types of teeth in our mouth:

• Incisors– front teeth in the form of a cutting chisel with sharp edges (8 in total, 4 on each arch). Their function is to cut pieces of food into optimal size. The upper incisors have a wide crown, the lower ones are twice as narrow. They have a single cone-shaped root. The surface of the crown has tubercles that wear away over the years.
• Fangs – chewing teeth designed for separating food (4 in total, 2 on each jaw). On the back side there is a groove dividing the crown into two unequal parts. The crown itself is cone-shaped due to one pronounced cusp, so these teeth look like animal fangs. Canine teeth have the longest root of all teeth.

• Premolars– these are small molar chewing teeth (4 on each jaw). They are located behind the canines towards the central incisors. They are distinguished by a prismatic shape and a convex crown. On the chewing surface there are 2 tubercles, between which there is a groove. Premolars differ from each other by their roots. In the first it is flat and bifurcated, in the second it is cone-shaped with a larger buccal surface. The second is larger than the first, the depression in the enamel is shaped like a horseshoe.
• Molars– large molars (from 4 to 6 on each arch, usually the same as the number of small molars). From front to back they decrease in size due to the structure of the jaw. The first tooth is the largest - rectangular in shape with four tubercles and three roots. When the jaw closes, the molars close and serve as stoppers, so they are subject to great changes. They bear a colossal burden. “Wisdom teeth” are the outermost molars in the dentition.

The arrangement of teeth on the plates is indicated by a special generally accepted diagram. The dental formula consists of numbers indicating the teeth - incisors (2), canines (2), premolars (2), molars (3) on each side of one plate. It turns out 32 elements.

The structure of the teeth of the same name on the upper and lower jaw of a person has differences.

Bottom "players"

On your upper jaw The following teeth can be found:

• Center incisors (1)– chisel-shaped teeth with a dense crown and one cone-shaped root. On the outside, the cutting edge is slightly beveled.
• Side cutters (2)– chisel-shaped teeth with three tubercles on the cutting surface. The upper third of the rhizome is deflected back.
• Fangs (3)- similar to animal teeth due to pointed edges and a convex crown with only one cusp.
• I-th radical small (4)– a prismatic tooth with convex lingual and buccal surfaces. It has two tubercles of unequal sizes - the buccal one is larger, the flattened root of a double shape.
• II root small (5)– differs from the first in a large area on the cheek side and a cone-shaped compressed rhizome.
• 1st molar (6) is a large rectangular molar. The chewing surface of the crown resembles a diamond. A tooth has 3 roots.
• 2nd molar (7)– differs from the previous one in its smaller size and cubic shape.
• III molar (8)- “wisdom tooth”. Not everyone grows it. It differs from the second molar in having a shorter and coarser root.

Top "players"

The teeth of the lower arch have the same names, but differ in their structure:

• Incisors in the center- the smallest elements with a small flat root and three tubercles.
• Incisors from the side– larger than the previous incisors by a couple of millimeters. The teeth have a narrow crown and a flat root.
• Fangs– diamond-shaped teeth with a convexity on the tongue side. They differ from their upper counterparts in having a narrower crown and inward deviation of the root.
• 1st root small– a round-shaped tooth with a beveled chewing plane. It has two tubercles and a flattened root.
• II root small– larger than the first, distinguished by identical tubercles.
• 1st molar– a cube-shaped tooth, has 5 tubercles and 2 rhizomes.
• 2nd molar– identical to I.
• 3rd molar– characterized by a variety of tubercles.

Features of teeth

What is the fundamental difference between the front teeth and chewing teeth? Functional differences were laid down by nature.

• This determined their shape and structure. As mentioned above, they are distinguished by a pointed crown and a single flat rhizome.
• Molars and premolars (lateral teeth) are needed for chewing food, hence the name “chewable”. They bear a large load, so they have several strong roots (up to 5 pieces) and a large chewing area.

One more feature side elements– high exposure. After all, food residues accumulate on their surface, which are difficult to remove with a toothbrush.

In addition, this area is difficult to see with ordinary eyes, so it is easy to miss the first signs of damage. It is these teeth that are most often subject to extraction and implantation.

Wisdom comes with pain

The most “sick” tooth- This is a wisdom tooth. It's a shame that it doesn't bring any benefit; its functions have long since sunk into oblivion. And lucky are those for whom it remains in its infancy and does not strive to grow.

The anatomical structure of the third molar is no different from other teeth. It simply has a shortened trunk and several tubercles.

All a person should have four “wise” teeth– 2 on each arc.

But “wise” teeth erupt later than others - in the period from 17 to 25 years. In rare cases, the process is delayed until old age. The older the individual, the more painful it will be for him.

These teeth may only seem half(semi-retained teeth) or remain undetected (impacted teeth). The reason for this harmfulness is the structure of the jaw of today's man. “Wise” teeth simply do not have enough space.

A refined diet and a large brain size corrected the jaw apparatus.

Third molars have lost their functionality. Scientists still don't have an answer why they continue to grow.

Pain during the eruption of the third molar is felt due to its overcoming mechanical impact, because the jaw has already formed. Growth can be accompanied by various complications.

It happens that it lies horizontally, comes into contact with the nerve, puts pressure on the “neighbor”, provoking its destruction. If the third molar is pushing against the tongue or cheek, inflammation and injury cannot be avoided.

Another unpleasant diagnosis is pericoronitis. A “wise” tooth can erupt for years, and the mucous membrane suffers because of this.

Chronic inflammation occurs and the gums become dense.

As a result, it appears slimy hood, which provokes purulent processes. This problem can only be solved by a dentist through surgical intervention.

Many people think about having a useless and painful wisdom tooth. If it has grown correctly and does not cause any discomfort, it is better to leave it alone. Sometimes the dentist recommends removing the second molar so that the third molar can be placed in its place.

If the wisdom tooth is very painful, then it is better to remove it, there's no need to delay this. Over the years, it settles more and more tightly in the gum; this, when removed, can cause some problems.

Curious facts

What else do we know about teeth besides the fact that they need to be brushed?

• Twins and twins also duplicate their dental “composition”. If one is missing a specific tooth, then the other is missing it too.
• A right-handed person more often works with the right side of the jaw, a left-handed person works accordingly.
• The jaws are designed to huge load. The maximum chewing muscle force approaches 390 kg. Not every tooth can do it. If you chew nuts, you create a pressure of 100 kg.
• Elephants change teeth 6 times. Science knows of a case where a 100-year-old man's teeth changed for the second time.
• The enamel on teeth is considered the hardest tissue, which is reproduced by the human body.
• The tooth can be stored for a long time even at temperatures above 1000 degrees.
• 99% of calcium reserves are found in human teeth.
• Science has proven that strong teeth are a sign of good memory.
• The most expensive tooth belongs to the scientist Newton, it was sold in the 19th century for 3.3 thousand dollars. The buyer of aristocratic origin decorated the ring with it.

• Legend has it that Buddha had 40 teeth, and Adam had 30.
• Neanderthals did not have tooth decay because they ate healthy food.
• Some babies are born with a prenatal tooth in the lower jaw (1 in 2,000 cases).
• Each row of teeth is unique like fingerprints.

We mistakenly do not consider teeth to be an important organ. But this is a complex and fragile system. Each tooth has its own characteristic structure and performs a specific function.

A person's bite changes only once, so we must take good care of your teeth from the first days of life. Nature did not give us a chance for a second healthy jaw.

The more facts we know about teeth, the more interesting it is to clean them and the easier it is to care for them.

When asked how many teeth an adult should have, everyone will answer without delay: According to the norm, 32 teeth. But if you take the topic seriously and count the number of teeth on the upper and lower jaw, you may be surprised, since there will be fewer than the expected number. Let's try to find out why this happens, which cases can be considered normal, and which require medical intervention.

Features of the growth of baby teeth

Babies are completely missing teeth. Sometimes there have been cases of babies being born with a pair of milk elements, but this circumstance is an exception. Pediatricians say that teething should begin at about 7–8 months of a baby’s life, but there are often situations when parents notice the appearance of the first incisors already at 4–5 months.

All baby teeth grow in before the age of three, but this general date often shifts by six months in one direction or another. According to dental experts, this development of events is normal.

Teething order

The chronology of the formation of milk teeth in infants is as follows:

• The incisors are the first to erupt into the oral cavity. By 8–9 months their number should be 4: two on top and two on bottom.
• By the time a baby reaches one year, the jaw row should number eight to ten teeth, but sometimes there are twelve of them, which is again normal. At this time, the lateral incisors grow.
• By the age of two, a little person has eighteen to twenty elements in his mouth. By 18 months the first molars appear, by 24 months the canines appear, and then the second molars. Thus, by the age of 2, a person has 8 incisors and molars, as well as 4 canines.
• After two years and 6 months, the so-called resting period begins, when tooth growth slows down. But for a small person, the twenty that is available is enough to chew food. At this age, an important task for parents becomes hygienic education of children, explaining the need for cleanliness and oral health.

How many permanent teeth do adults have?

According to the norm, an adult person should have 32 teeth: 16 on top and bottom respectively. The dental composition on the upper and lower jaws is the same; only the shape of its individual elements may differ slightly.

Incisors

The number of permanent incisors in an adult is equal to the number of baby teeth of the same name in children: 4 on each jaw. They can be central or lateral. In the top row the central elements are large, and in the bottom row the side elements are larger. This formation allows them to optimally perform the function of biting, “cutting” pieces of food.

Fangs

Both babies and mature people have 4 such teeth: 2 on top and 2 on bottom. The shape of the fangs is in many ways similar to that of carnivores.

Molars

They perform the function of chewing and grinding food, and can be of two types:

• Premolars or small molars. The number of such teeth in an adult is usually eight: 2 pairs on each jaw. They are located between the canines and molars. One premolar has a rounded shape and is placed at an angle towards the tongue. The second premolar is larger than its counterpart, covered on top with pronounced tubercles.
• Large molars or molars. An adult person has 12 such teeth, they differ by type. The first molars are large, rectangular in shape, have pronounced cusps and two roots, each of which contains one dental canal.

The second and third molars are similar to the first, with some differences only in the shape of the fissures and cusps.

Adults usually have four wisdom teeth—third molars—but sometimes there may be fewer of them, or they may not grow at all. If there are no wisdom teeth in a person, there are 28 positions in the mouth. For what reasons this happens, read below.

Why don't all people have wisdom teeth?

It is not for nothing that wisdom teeth received such a name, since they appear in adults - from 18 to 25-26 years. These teeth often do not grow in full numbers, for example, one on each jaw, or do not erupt at all. If the growth of the third molars proceeded without complications, the discomfort went away after complete eruption, then any number of them will be a variant of the norm.

Output: 32 permanent teeth in humans this is the standard norm, along with “wise” teeth. But many people grow only 28 permanent teeth, and dentists also consider this to be normal, saying that during the course of evolution, “wise” elements may disappear altogether.

In rare cases, on the contrary, a person has 33 teeth, the fifth “sage” erupts in the front of the row. This phenomenon entails discomfort and spoiled aesthetics of the jaw, so the excess element must be removed.

According to experts, an additional third molar is a deviation from the norm, which is formed during intrauterine formation. For example, if the pregnancy was multiple and one of the embryos died, passing on an “extra” tooth to a brother or sister.

Modern dentistry helps to easily cope with any dental ailments. But, as before, the main condition for dental health is daily brushing twice a day, visiting the dentist at least once every six months and timely treatment of dental diseases.

A beautiful smile with healthy white teeth suits anyone. It is considered an important indicator not only of health, but also of success. Even in ancient times, good teeth indicated that their owner’s diet was good and varied.

Teeth are a kind of bone formation that crushes food into smaller components for its further absorption by the body. Human teeth are small, white or yellowish in color, and are made up of 95% calcium. These are the only organs that cannot be regenerated.

The number of teeth depends on various factors and for an adult the number is usually 32 teeth:

• lateral and central incisors 8;
• fangs 4;
• premolars 8 (small molars);
• 12 molars (major molars).

Many dentists believe that they are involved in grinding food, since in a normal position they can make the chewing function more active, but molars are more susceptible to caries than other molars.

Some dentists believe that it is better to remove third molars, especially if they grow incorrectly, interfere, do not perform their functions and can cause complications.

Dental indications for removal:

• caries that cannot be cured;
• indications from an orthodontist due to crowded teeth, leading to a shift in the main molars;
• injury to soft tissues by the coronal part caused by incorrect position.

The process of removing the figure eight leads to a reduction in pain, preservation of the shape of the face with a certain arrangement of teeth and helps to avoid infection with various infections.

What structure do teeth have?

The anatomical and histological type of tooth structure is distinguished, and the structure of the enamel and root is also indicated separately:

• Anatomically, a tooth is divided into three components: root, neck, crown.
  Crown – rises above the gum, covered with enamel.
  According to the type of crown there are:
  • facial;
  • occlusion - the place where paired teeth of opposite jaws meet;
  • contact;
  • lingual.
    The root and crown are connected by a neck covered with cement and covered with gum.
    The root is what attaches the tooth to its socket. It is single-stemmed or with several branches.
• According to the histological type, the structure of the teeth is identical, but they have different shapes:

• Enamel– this is a dense tissue that is highly durable and is responsible for protecting the tooth from harmful bacteria; it consists of 94% salts: zinc, magnesium, fluorine and iron. Carbohydrates, proteins and lipids make up the remainder. Enamel also contains a certain amount of liquid elements that participate in physiological processes.
  The outer shell of enamel is the cuticle.. It is used for chewing, as it has a fragile structure, can wear off over time, and therefore requires care. Every tooth is covered with enamel.
  Warp bone tissue , located under the enamel, is a complex of minerals that surround the root canal and the entire dental cavity. The smallest channels of dentin tissue help in the processes of nutrient metabolism and transmit nerve impulses.
• Root.
  Pulp and periodontium:
  • Pulp– a cavity inside the tooth (with loose tissue), has nerve endings and blood vessels. Participates in providing nutrition and exchange of elements. When removed, these processes slow down or stop altogether.
    There is a recess in the jaw - the alveolus - this is where the root is placed. It contains mineral tissue and is covered with cement on the outside.
    The end of the root is the apex, which has blood vessels that nourish the dental tissue. The number of roots varies from 1 to 5.
  • Periodontium– this is connective tissue, a connecting element that can fill the void between the jaw socket and the tooth root. Through periodontal tissue dental system nutrients get in.

How many canals do human teeth have?

The channels differ from each other in shape and structure, and their number may differ from the number of roots. The number of canals is determined by the dentist using x-rays. However, none of the doctors will give clear rules on their number.

Approximate quantity per different types teeth:

Several channels can be located in parallel in one root.

How many roots does a wisdom tooth have?

• The number of roots in eights varies from 2 to 5, the length is 8-10 mm. Their roots are curved and this can cause difficulties during dental intervention.
• Externally, a wisdom tooth is not very different from other molars. Whether they grow or not depends on many factors: jaw size, heredity, etc. The rudiments are formed around 3 years of age.
• Sometimes the eruption process lasts up to 40 years. Tooth growth lasts about 1.5 months. The unpleasant sensations in this case can be explained by the fact that eights do not have the first milk teeth; they have to erupt through dense bone tissue.
• When properly cut, the figure eight lasts a long time.

How many times a day should you brush your teeth?

To maintain healthy teeth and have a full set of them until old age, you need to maintain oral hygiene. But many people do not pay enough attention to brushing and caring for their teeth, and as a result they wonder why problems arise. After all, even the most expensive toothpaste may not help in this case.

1. Teeth should be brushed no more than 2 times a day(morning and evening), since frequent brushing can destroy enamel, damage gum tissue, and cause dryness and irritation of the oral mucosa. But, if there is excessive consumption of sweets, then it is better to use toothpaste.
2. You can combine cleaning in the morning with gum massage and tongue cleansing. In the evening, you can use herbal paste and dental floss.
3. Better to use paste with minimal or no fluoride.
4. Clean the mouth after breakfast and dinner, at least 30 minutes after eating. Since food enzymes can react with elements of toothpaste, which can lead to adverse consequences.
5. Helps remove plaque at home apples and raw carrots, soda and tooth powder (the last two no more than once a month).
6. During the day after a snack It is better to rinse your mouth with special liquids, but you can also use plain water. Dental floss and chewing gum are also suitable (chew for no more than 15 minutes)
7. Optimal time for brushing teeth is 2 minutes, no less. And in order not to violate the integrity of the gums, you need to make soft circular movements. Alternatively, you can choose an electric toothbrush.
8. Refuse from bad habit: smoking.

These simple tips will help prevent the development of caries, gum disease and keep your teeth healthy and strong. for a long time.

Baby teeth and the process of changing to molars

The roots of baby teeth are able to dissolve on their own, then they become loose and fall out, freeing up space for the primary teeth.

All milk teeth (20 pcs.) are completely replaced by molars by the age of 13-14 years. The first molars often grow into primary molars long before the replacement of primary molars.

Approximate drop order:

The replacement of primary teeth with primary teeth usually occurs between 4 and 8 years of age, but for each individual child this may be different. Therefore, it is more important to consider the order of drops.

The timing of tooth loss depends on several factors:

1. Genetic predisposition.
2. Purity and mineralization of water.
3. Quantity and quality of food.

Tooth growth abnormalities

Dental anomalies can be congenital or acquired and are divided into:

• number– adentia (lack of teeth), hyperdontia (the number of teeth is higher than normal);
• size– small and giant teeth (micro- and macrodentia);
• external type(spike-shaped, Fournier teeth (screwdriver-shaped), etc.);
• color characteristics(change in enamel color due to pigmentation);
• location:
  • Distal and mesial – displacement of teeth back or forward;
  • Vestibular – teeth move closer to the oral cavity;
  • Supra- and infraposition - teeth are located above or below the occlusal curve;
  • Transposition - interchangeable arrangement of teeth (the canine grows instead of the lateral incisor, for example).
• growth time(premature, belated);
• density of the tissue structure of teeth:
  • Enamel hypoplasia– the presence of all kinds of stains and grooves on the outer part of the tooth.
  • Amelogenesis imperfecta– pigmentation in a yellow or brown tint, enamel is thinner than normal, increased sensitivity of teeth to temperature.
  • Imperfection of dentinogenesis– improper development of dental dentin. They become amber or grayish-brown in color and may break down and fall out.

If there are disorders, the jaw may become deformed, speech may be impaired, the bite may change, and there may be difficulties when biting off and chewing food.

Diagnosis is carried out using a variety of methods, including: radiography, taking impressions, electromyography and others. Treatment depends on the type of dental anomaly and can be surgical or orthodontic.

Dental abnormalities occur due to various reasons:

• genetic (family variations in the sizes and types of teeth, jaws, etc.);
• prenatal (exposure to poor ecology during pregnancy; multiple pregnancies, intrauterine infections, stress);
• intrapartum (umbilical cord entanglement during childbirth, asphyxia, intracranial bruises, prolonged anhydrous);
• postnatal (rickets, excess vitamins, improper nasal breathing due to damage to the nasal septum);

Local influences: wrong artificial feeding, long-term use of pacifiers, soft foods in children preschool age, shortened frenulum of the lip and tongue, advanced caries.

Color anomaly: damage to the tooth, due to which various coloring substances get there; such damage can also be accompanied by internal hemorrhage, exposure to nicotine, demineralization of enamel, poor-quality filling.

Conclusion

The human dental apparatus is a complex system where all elements perform their specific function and properties. Teeth change only once in a lifetime, and this makes the structure of the human jaw different from the anatomy of the jaw of animals.

It is believed that a normal adult has 32 teeth in his mouth, while a child has only 20 baby teeth. But this is not always the case. There are a number of factors that can change the amount, and in some cases it will not even be considered pathological.

The structural features of human organs and systems are laid down during the period of conception. This is the so-called genetic information. The same thing happens with the number of teeth in the future. However, during the process of growth and development of the body, their number may change due to many factors.

Growth and development

Teeth develop from the remains of the oral epithelium. As the child grows, so do they. Their formation begins from the coronal part. Being in the form of a rudiment for a long time, they go through a stage of calcification (ossification) from the crown towards the root.

When the time comes, the rudiment slowly moves towards the edge of the alveolar process. The gum is deformed and gradually resorption occurs. Thus, the tooth seems to have a way out. A newly erupted tooth does not have full roots. They take another 1-2 years to form.

Factors affecting the number of teeth

There is evidence that in the past a person had not 32 teeth, as is considered the norm today, but as many as 44. During the process of evolution, certain changes occurred in food consumption. It became softer due to the fact that it began to be subjected to heat treatments, and the need for more thorough chewing disappeared.

Now an adult may have fewer teeth. This is affected by the following:

• Genetic feature;
• Death of the embryo as a result of injury;
• Underdevelopment of the embryo due to severe illnesses (especially infectious) of the mother during pregnancy and of the child in the early years of life;
• Early removal of a baby tooth;
• Lack of wisdom teeth.

Depending on anatomical structure and location, they all have some purpose. But teeth are not only involved in the process of eating, they are also very important for correct speech pronunciation. Dentists are often asked what types of teeth are there and what they are intended for, as well as how many roots a person’s teeth have?

There are 5 groups of teeth:

1. Incisors

Their total number 8. Four central incisors and 4 lateral incisors, two on each side of the jaw. They play an important role in biting solid food and producing sounds. They have a very sharp cutting edge and a flat crown.

They each have one root, slightly compressed relative to the vestibular and lingual sides of the alveolar process. The canal is fundamentally thin, straight and practically without an aperture at the transition from the pulp chamber.

1. Fangs

These are the next units behind the incisors. Their cutting edge is made in the form of a pointed tip. They assist the incisors in tearing food and grinding it. Normally there are 4 fangs. Each of them has one very powerful root. Its apex is slightly curved distally, but this is typical of the roots of the upper canines. On the lower jaw they are straight up to the apical foramen.

1. Premolars or small molars

There are two of them on each side. With the help of such teeth a person grinds hard and soft food. On the upper jaw, the first premolar has two roots (from the buccal and palatal sides), the second has one root. On the lower jaw, both teeth have one root.

1. Molars or large molars

The first molar and second molar in the upper jaw have three roots each and three canals running directly into them. Two roots are located on the buccal side, and one on the palatal side. On the lower jaw, molars have two roots, but 3 canals. The roots are located in the distal and medial directions. There are 2 canals located in the distal root.

Thanks to the powerful and wide crown, they perfectly crush any food, bringing it to a mushy consistency.

1. Wisdom teeth (“eights” or third molars)

Of course, they can be classified in a single group with molars. But these units are not always present in the dental arch, their structure is not entirely correct, and they often do not erupt quite normally. They have a different number of roots or they are often underdeveloped, welded together and strongly curved.

There are 4 wisdom teeth, one on each side of the jaw. However, there are also cases when a person has 1, 2 or only 3 “wise” teeth. Many consider them unnecessary and remove them before they become diseased or deteriorate. Dentists say that this should be done strictly according to indications.

The fact is that these teeth can replace the second molar if it is removed early, since third molars appear both at 20 years old and at a later age. Thanks to this, the impact of carisogenic factors on them is, as it were, delayed. Replacement is only possible when the eights are positioned perfectly evenly. They will simply slowly move to the place of the removed tooth.

*Total number of roots is approximate. Since all teeth, which usually have more than one root, can sometimes have fewer.

Thus, together with wisdom teeth, an adult has a normal 32 teeth. But if, after the formation of a permanent dentition, several eights are missing, this is also considered normal.

They are quite similar to the constants, but still have some differences. Firstly, the child has not 32, but only 20 teeth. They are missing premolars and one molar. The dental arch contains 8 incisors, 4 canines and eight molars. Their purpose is the same as in the permanent dentition.

The difference between temporary teeth and permanent teeth is as follows:

• the crown is smaller in size;
• the roots are massive, but highly branched;
• the enamel has a white-blue color;
• hard tissues are less durable and therefore more susceptible to carious destruction;
• deeper fissures;
• The tubercles and signs of crown curvature are more pronounced.

The replacement of baby teeth begins at 5-6 years of age. By the age of 14, the permanent dentition is usually fully formed. Deviation is allowed for one year. If the process of changing the bite is delayed, this can lead to abnormalities in the dental arch and the formation of the jaws themselves. Therefore, you should immediately contact your dentist to identify and correct the problem.