The development of teeth in a child. Human tooth structure: diagram

01.07.2020

The timing of the appearance of the first teeth does not mean anything. Different children develop teeth in different ways. Some children chew everything, be capricious and whimper 3-4 months before the appearance of each tooth and spoil the life of all family members. And in other children, teeth erupt painlessly, and the mother finds them by chance one fine day, without suspecting that the child has grown teeth.

In a relatively healthy child, the age at which teeth appear is determined by heredity. In one family, almost all children have teeth earlier, and in another, later. Don't think that your child is better than another if he or she has teething early. And do not assume that your child is mentally and physically retarded because his teeth appeared late.

How a child's teeth grow

As a rule, the first teeth appear about 7 months, but from 3-4 months the child whines, bites everything and cries periodically.

In the first 2.5 years, a child should have 20 teeth, so it is not surprising that almost any ailment during this period is so easy to explain by teething.

In the past, teething was considered the cause of colds, diarrhea, and fever. Of course, the cause of these diseases is not teething. However, in some children, teething reduces the general resistance of the body, and they become sick more easily during this time. Therefore, if a child gets sick during teething or the temperature exceeds 38 °, it is necessary to call a doctor for a diagnosis and treatment.

Usually, the two lower central teeth appear first (the 8 front teeth are called incisors). After a few months, the four upper incisors are cut. Usually, by the age of one year, a child has 8 teeth (4 at the bottom and 4 at the top).

Then there is usually a break of several months, after which 6 more teeth are erupted almost one by one: 2 remaining lower incisors and 4 molars, which are located on the lateral sides of the jaw. Between the molars and the incisors, there is room for the canine teeth (pointed at the ends), which appear several months after the molars. As a rule, they erupt in the second half of the second year.

4 more molars grow last, usually in the first half of the third year of life.

When teeth are teething, the baby often wakes up at night. The first four molars are especially painful. The child may be capricious and lose appetite for several days. He may wake up several times during the night. If he does not fall asleep quickly again, then this can be a problem. The easiest way to calm your baby is to give him milk from a cup or nipple. Isn't it risky? In most cases, the baby stops waking up as soon as the teeth erupt.

But sometimes children develop a habit of waking up at night, especially if they are picked up and taken care of. Therefore, I think that it is better not to feed the child at night and not to pick him up if he falls asleep himself after a few minutes. If you have to feed him at night, do it in the crib, but as soon as the teeth erupt, stop this practice immediately.

When the first teeth grow in the middle of the first year of life, the child often wakes up at night too. Give your child a chance to chew.

Some mothers feel it is their duty not to let their baby put anything in their mouth. But most babies just need it for at least 6 to 15 months. The constant struggle will exhaust both mother and child. It is wiser to provide the child with chewing objects that should not have sharp corners and edges so that the child does not injure himself if he falls. Rubber rings are very convenient for this purpose, but any piece of rubber that is comfortable for a child to hold in his hand will do.

Be careful with fine celluloid toys. Sometimes babies will chip off small pieces of celluloid, swallow them, and may choke. Make sure your child does not chew paint on furniture or other objects. Some children prefer to chew on a piece of cloth. Allow your child to chew whatever he wants, except objects that are dangerous to him.

Don't be afraid of bacteria living on the objects it chews. These are his own bacteria, to which he has long been accustomed. Of course, wash the ring with soap and water if it falls to the floor or if a dog grabs it. Boil, from time to time, the rag that the child chews. Some children enjoy a strong gum massage.

How to strengthen your teeth. First of all, it must be remembered that the crowns of the teeth (that is, the part of the teeth that protrudes on the surface of the gums) are formed in the gums long before the birth of the child from those substances that the mother receives with nutrition during pregnancy. Studies have shown that the following substances are especially useful for strengthening teeth: calcium and phosphorus (milk and cheese), vitamins D (in the form of concentrate and sun rays), vitamin C (in the form of concentrate, oranges and other citrus fruits, fresh tomatoes, cabbage). Vitamin A and some B vitamins appear to be as essential as other substances.

A child's permanent teeth, which do not appear until the age of 6, begin to form a few months after birth. at this age, the child receives large amounts of phosphorus and calcium from milk. From the age of one month, the child should receive vitamins C and D (usually they are given to newborns in the form of concentrates).

In countries where fluoride is found in water, teeth are destroyed much less. In many countries, fluoride is added to water. If it is absent in the water, the dentist can partially compensate for this deficiency by applying a thin layer of fluoride to the child's teeth. Until now, some people rebel against adding fluoride to water, considering it harmful, despite the careful research of scientists and their conclusion about the benefits of such a measure. But at one time, many objected to both universal vaccination and the chlorination of water, although now it has become commonplace.

Sugar and starchy foods contribute to tooth decay. Scientists have not yet found an exhaustive answer to the question of why teeth are decaying (a phenomenon called caries). The nutrition of the woman during pregnancy and the nutrition of the baby are certainly very important for the prevention of tooth decay. Heredity also plays a role.

Even strong-looking teeth can begin to deteriorate. Dentists believe that the destruction is caused mainly by lactic acid, which is produced by bacteria that live in sugar and starch stuck in teeth. The longer the remains of this food are on the teeth, the more bacteria multiply and the more lactic acid is produced, which eats away at the holes in the teeth. This is why chewing sweets (candy, biscuits, dry fruits, sugary drinks, cakes) between feeds is especially conducive to tooth decay.

Of course, fruits and even vegetables also contain sugar. But in them it is in a dissolved state and therefore is more likely to be washed off. The coarse fiber in fruits and vegetables acts like a toothbrush on the teeth. We all eat starchy foods, but usually only at certain times. In addition, bread, coarse grains and potatoes do not stick to teeth for long. Teeth suffer from frequent off-schedule "snacking" (especially if it is food that stuck in the teeth for a long time, like sweets and starch).

Dental care

Some doctors advise to start brushing a child's teeth when the first 4 molars appear, that is, approximately in the first half of the second year of life. I think it's better to wait up to 2 years. At this age, the child enthusiastically copies everything that adults do. If his mother and father brush their teeth, he wants to try too. Buy him a toothbrush as soon as he shows interest in it and let him try. Of course, at first he will not succeed, but you will tactfully help him. You will say that I am speaking in too much detail on this topic. I just want to show with this example that there is no need to force a child to do something, as many adults are sure, because in due time he will do with great pleasure what adults may consider an unpleasant duty. But just give him the opportunity to learn himself.

The main purpose of brushing your teeth is to remove food debris from the surface. You need to brush your teeth after every meal, 3 times a day. It is especially important to brush your teeth after dinner to keep them clean through the night, when very little saliva is produced.

Take your child to the dentist 2 times a year from the age of 3. Teeth usually begin to decay from the age of 3. Seal them while the holes are still small. This is, firstly, to save the tooth, and secondly, it will cause the child less pain. Even if the teeth of a three-year-old child are intact, it still makes sense to take him to the dentist for two reasons: to make sure that the teeth are healthy, and so that later the child would go to the dentist without fear. If the first time he was not hurt, he will not be afraid to insert a filling when it is first needed.

Often, parents think that it is useless to take care of baby teeth, as they will fall out anyway. It is not right. A decaying baby tooth can also hurt, and through it, an infection can penetrate the entire jaw. If a diseased tooth has to be removed, then due to the resulting empty space, the adjacent teeth grow incorrectly and subsequently will interfere with the growth of the molar. Remember that the last baby teeth only fall out at age 12. Therefore, they need the same careful care as the permanent teeth.

Permanent teeth

They start to appear around 6 years old. The permanent molars grow after the milk molars. The lower central incisors fall out first. When permanent teeth grow, they destroy the roots of milk teeth, loosen them until they completely fall out.

Milk teeth fall out in the same order in which they appear: incisors, molars, canines. The process of replacing milk teeth with permanent ends only at 12-14 years old. After the molars that grow at the age of 6, the second molars appear at about 12 years.

Wisdom teeth grow much later, at about 18 years old (and sometimes do not grow at all).

Sometimes permanent teeth grow crooked or misaligned, but over time they become somewhat aligned. True, it is difficult to say in advance how much they will improve. A dentist who checks your child's teeth every 6 months may prescribe treatment.

The development of teeth is a very complex process that begins in the early stages of development of the embryo and continues in humans up to 18-20 years. This process can be divided into several periods. The period is from the moment of birth to 6-7 months, when the child does not yet have teeth, but the rudiments of milk teeth are already laid in the jaws, starting from the 40-45th day of intrauterine life. The first milk tooth appears in a newborn at 6-7 months of age. The period is from 6-7 months to 6-7 years. During this period, a milk bite develops. During that time, all 20 milk teeth erupt and grow. In the formation of a milk bite, in turn, two stages are distinguished: the first begins from the moment of eruption at the age of 6-7 months and ends with the complete formation of the dentition at 2-3 years; the second stage lasts from 2.5-3 to 6 years. At this time, the milk teeth are prepared to be replaced by permanent ones. The period begins at the end of the 6th year of life and lasts up to 12-13 years. It is characterized by the gradual change of milk teeth to permanent 32 teeth.

The formation of milk teeth is completed in the period by the 3rd and 5th years of life. Further, there is an intensive increase in the height of the alveolar process and the growth of the jaws. Therefore, most children in a milk bite have pronounced spaces between the front teeth. The first permanent large molar erupts at the age of 6-7 years. Around the same time, the incisors of the lower jaw erupt. This initially leads to a slight crowding of the teeth, which should not be considered as a violation of the development of the bite, since by the age of 12, due to the intensive growth of the jaws, the bite is normalized.

The difference between milk teeth and permanent ones.

Contrary to popular belief, milk teeth, as well as permanent ones, have roots and a nerve (pulp). The roots hold the tooth in the bone. Under the milk tooth is a permanent rudiment. As the eruption proceeds, the permanent tooth stimulates the resorption of the roots of the deciduous tooth and by the time the deciduous tooth falls out, only the crown remains.

Since deciduous teeth (like permanent teeth) have a nerve (pulp), they can hurt if a carious infection enters the tooth cavity, causing pulpitis.

Milk teeth differ significantly from permanent teeth in their size and structure.

Milk teeth are smaller than permanent teeth and have less massive roots;

Milk teeth have a more complex anatomical structure of root canals, which leads to a more time-consuming treatment process than in permanent teeth;

The hard tissues of milk teeth are less mineralized and have less resistance to abrasion and the development of a carious process.

The hard tissues of milk teeth are much thinner than that of permanent ones: the inflammatory process quickly reaches the tooth nerve;

Why are baby teeth needed?

Baby teeth are involved in the development of such functions in a child as chewing and pronunciation of sounds. Chewing tough food would be impossible without them. The aesthetic component plays an important role.

Also, baby teeth hold space in the dentition for permanent teeth. The eruption of deciduous teeth stimulates the primary growth of the jaws. The second wave of jaw growth begins during the replacement of primary teeth with permanent ones. Early extraction of deciduous chewing teeth leads to displacement of adjacent teeth to the area of \u200b\u200bthe missing one and the formation of crowding of teeth in the future!

Odontogenesis.

Odontogenesis - the development of a tooth - begins at the 6th week of embryogenesis, when the follicles of milk teeth are laid, and sometimes completely ends after 20 years, when the third permanent molars erupt and the formation of their roots ends.

Human teeth develop from components of the oral mucosa of the embryo. Its epithelium gives rise to the structural elements involved in the formation of enamel, and the mesenchyme is the source of dentin, pulp and cement.

In the development of each tooth, 3 periods are distinguished: the laying of tooth germs, their differentiation and histogenesis - i.e. development of the main tooth tissues (enamel, dentin, pulp, cement).

Bookmark dental germs.

Initially, in the area of \u200b\u200bfuture anterior teeth from the vestibular plate at a right angle, a dental plate originates, growing into the underlying mesenchyme. In the process of their growth, epithelial dental plates take the form of two arches located in the mesenchyme of the upper and lower jaws.

Then, along the free edge of the plate on the anterior (buccal-labial) side, flask-shaped protrusions of the epithelium (10 in each jaw) are formed - dental kidneys (gemmae dentis). At 9-10 weeks of embryonic development, the mesenchyme begins to grow in them, giving rise to the dental papillae (papillae dentis). As a result, the tooth kidney takes the shape of a bell or bowl, transforming into an epithelial dental organ (organum dentale epitheliale). Its inner surface, bordering on the mesenchyme, bends in a peculiar way and the outlines of the dental papilla gradually acquire the shape of the future tooth crown. By the end of the 3rd month of embryogenesis, the epithelial dental organ with the dental plate is connected only by a narrow epithelial cord - the neck of the dental organ.

Around the epithelial dental organ and under the base of the dental papilla, a thickening of the mesenchyme forms - a dental sac (sacculus dentis)

Thus, in the formed tooth germ, 3 parts can be distinguished: the epithelial dental organ, the mesenchymal dental papilla and the dental sac. This completes the 1st stage of tooth development - the stage of laying the tooth germs, and the period of their differentiation begins.

Differentiation of dental germs.

First, the dental organ is divided into several cell layers. In its central part, a protein liquid accumulates between the cells, pushing them apart. These cells acquire a stellate shape, and their totality forms the pulp of the dental organ (pulpa organi dentis). The cells of the dental organ adjacent to the surface of the dental papilla become cylindrical and are called the internal dental epithelium (epithelium dentale internum). These cells give rise to enameloblasts, which are involved in the formation of tooth enamel.

Between the enameloblasts and the pulp of the dental organ, there are several rows of flat or cubic cells that form the intermediate layer of the dental organ (stratum intermedium). The outer surface of the dental organ is formed by flattened cells of the outer dental epithelium (epithelium dentis externum)

Subsequently, the cells of the outer dental epithelium gradually atrophy, and the cells of the intermediate layer of the enamel organ and its pulp take part in the formation of the enamel cuticle.

So, as a result of the differentiation of the dental organ, its pulp, internal and external dental epithelium and the intermediate layer can already be distinguished in it. Then the dental papilla differentiates. By this time, it increases in size and penetrates deeper into the dental organ.

Blood vessels and nerve fibers penetrate into the base of the dental papilla, growing towards its apex. On the surface of the mesenchymal dental papilla, several rows of densely located cells are formed - premontoblasts, which later give rise to cells with basophilic cytoplasm - odontoblasts (dentin-forming cells). First, they form at the apex of the dental papilla, and later, on its lateral surfaces. The layer of odontoblasts is adjacent to the internal dental epithelium (enameloblasts), separated from it by a thin basement membrane.

By the end of the 3rd month of intrauterine development, due to the proliferation of the mesenchyme, the tooth buds separate from the dental plate, it loses its connection with the epithelium of the oral cavity and partially resolves. Only the deep sections of the dental plates are preserved and grow, which give rise to the rudiments of permanent teeth.

Tooth histogenesis.

By the end of the 4th month of embryogenesis, the period of differentiation of tooth rudiments is replaced by an intensively flowing period of histogenesis, during which dentin, enamel, pulp and cementum of the tooth are formed, and during embryogenesis, the laying and formation of crowns of milk teeth occurs, and their roots are formed after the birth of a child.

Dentinogenesis.

Dentin is the first dental tissue to form. Odontoblasts play an active role in this process. The nuclei of odontoblasts are oval in shape and are located in those sections of cells that are directed towards the center of the dental papilla.

In the process of dentinogenesis, proteins and acidic mucopolysaccharides are synthesized in the cytoplasm of odontoblasts, which are later removed outside the odontoblasts into the extracellular space (using a lamellar complex or in another way). In the intercellular space, as a result of enzymatic processes, thin long argyrophilic fibrillar structures - pre-collagen fibers are formed. This is how unusual dentin-predentin is formed. Peripheral divisions of odontoblasts turn out to be immured in predentin, which gradually elongate, turning into dentinal processes (Toms fibers).

Precollagen fibers of predin are mainly radial. They later turn into collagen fibers. When the pre-dentin layer reaches a thickness of 40-80 µm, it is pushed to the periphery by new dentin masses, in which collagen fibers lose their original orientation, being less ordered. These are tangential fibers that do not go through the pre-collagen stage, but immediately arise as collagen fibers.

A thin peripheral dentin layer containing radial fibers in its composition is called cloak dentin, and a powerful internal dentin with a predominantly tangential arrangement of fibers is called juxtapulpal (peri-pulp) dentin. As new masses of dentin are deposited, the processes of odontoblasts are lengthened, so that the bodies of these cells are not included in dentin, but are always located on the periphery of the dental papilla or dental pulp.

Odontoblasts not only form predentin, but also actively participate in the process of its mineralization. Dentin calcification begins at the 5th month of embryonic development.

A characteristic feature of dentin is the globular character of its calcification. Mineral salts in the basic substance of dentin are deposited in the form of hydroxyapatite crystals, which, merging with each other, are arranged so that the calcified areas of dentin take a spherical shape. Between these dentinal balls, there may be areas of uncorrected dentin - the so-called interglobular spaces or interglobular dentin. During life, areas of unusual interglobular dentin are usually retained in the crown of the tooth near the enamel and at the root at the border with cement. Dentin formation always precedes enamelogenesis and is a prerequisite for enamel formation.

Enamelogenesis.

After a narrow layer of preentin forms at the apex of the papilla, the enamel begins to develop. Enamel is formed by the secretory activity of the inner cells of the epithelial dental organ - enameloblasts. This process is preceded by some restructuring of the epithelial dental organ. Its outer surface forms numerous depressions into which the mesenchyme of the dental sac with blood vessels grows. Apparently, these vessels separated them from their previous source - the vessels of the dental papilla. This leads to a change in the physiological polarity of the enameloblasts: the cell nucleus and the lamellar complex change places. Now the basal (nucleated) part of the cell faces the pulp of the dental organ, and the apex with the lamellar complex is adjacent to the preentin. These enameloblasts are ready for enamel formation. A sign of the beginning of the functioning of enameloblasts is the disappearance of glycogen from the cytoplasm of these cells.

Pulp development.

The source of development of dental pulp is the mesenchyme of the dental papilla. Blood vessels grow into the base of the dental papilla already at the early stages of development of the dental germ. Almost simultaneously (starting from 9-10 weeks of embryonic development), nerve fibers begin to grow into the base of the dental papilla. Later, the hemocapillary plexus and nerve terminal branches are formed there.

The process of histogenesis of tissue elements of the dental papilla begins at its apex and gradually spreads to the base. Under the layer of odontoblasts, acquiring an elongated, pear-shaped, a layer of small stellate cells forms, forming a subodontoblastic layer of the pulp. The mesenchymal cells of the central parts of the dental papilla become larger and differentiate into fibroblasts, macrophages and adventitia cells. Between them accumulate pre-collagen and collagen fibers, as well as interfibrillar substance. So the mesenchyme of the central parts of the papilla is transformed into loose connective tissue of the tooth pulp.

Development of the roots and cementum of the tooth.

The development of the tooth root occurs in the postembryonic period and begins shortly before its eruption. After the crown of the tooth is formed, the epithelial dental organ for the most part is reduced, turning into several layers of flat cells tightly adjacent to the enamel and separating it from the surrounding mesenchyme. Soon, a kind of epithelial diaphragm is formed from them. This diaphragm subsequently grows into the underlying mesenchyme in the form of sleeves, and the number of sleeves is equal to the number of roots of the forming tooth. Single-rooted teeth of such sleeves have one, multi-rooted teeth have two or three.

(These sleeves are also called Hertwig's epithelial root sheaths.)

Mesenchymal cells adjacent to the sleeve from the inside turn into odontoblasts forming the root dentin. From the central section of this mesenchyme site, root pulp is formed.

When the epithelial arm disintegrates, the cells of the mesenchyme of the dental sac come into contact with the dentin of the root and turn into cementoblasts, which deposit acellular cement on the surface of the root dentin, consisting of collagen fibers and interfibrillar substance. Later, cell cement is formed, while the cementoblasts are walled up in the substance formed by them, turning into cementocytes. Periodontium develops from the external section of the mesenchyme of the tooth sac, connecting the root cement with the bony wall of the dental alveoli with bundles of collagen fibers. They become food sources for enameloblasts, since the predentin separated them from the previous source - the vessels of the dental papilla. This leads to a change in the physiological polarity of the enameloblasts: the cell nucleus and the lamellar complex change places. Now the basal (nucleated) part of the cell is facing the pulp of the dental organ, and the apex with the lamellar complex is adjacent to the prededentin. These enameloblasts are ready for enamel formation. A sign of the onset of enameloblast function is the disappearance of glycogen from the cytoplasm of these cells.

The process of formation of enamel prisms is as follows. Initially apical, i.e. facing the dentin, the area of \u200b\u200benameloblasts is somewhat narrowed, acquiring the appearance of a process. Then enameloblasts secrete the components of the organic enamel matrix - thin, interwoven fibrillar structures.

In this case, periods of activity of enameloblasts are replaced by periods of rest. As a result, Retzius lines appear in the enamel, intersecting the enamel prisms at an angle. These lines correspond to periods of decreased activity of enameloblasts; subsequently, a smaller amount of mineral substances is deposited here. At the end of enamelogenesis, enameloblasts are reduced. Their remains form an enamel cuticle on the surface of the crown.

After the formation of the organic base of the enamel, it calcifies. It starts from the dentin-enamel connection and extends to the enamel surface, is rhythmic in nature, as a result of which transverse ridge appears in the enamel prisms, and this first occurs at the apex of the future cutting edge of the crown, and then the process extends to its lateral sections. Calcification of enamel is especially intense after the enamel reaches its final thickness. It ends after teething.

Teething of milk teeth in children.

Teething usually begins closer to six months; on average, by the year the baby has 8 incisors, and the eruption of all 20 milk teeth should be completed by 2.5 - 3 years. However, the timing of teething can vary greatly - they depend on heredity, nutrition of the child. Therefore, the following possible dates and teething procedures are very approximate:

The first lower incisors are 6-9 months old.

The first lower incisors are 7-10 months old.

Second (lateral) upper incisors - 9-12 months.

Second (lateral) lower incisors - 9-12 months.

The first upper molars are 12-18 months.

The first lower molars are 13-19 months.

Upper canines - 16-20 months.

Lower canines - 17-22 months.

The second lower molars are 20-23 months.

The second upper molars are 24-26 months.

There was a time when it was believed that late teething was due to rickets, but this is not the case! Numerous studies in this area show that teething retardation is common to many normally developing babies. Milk teeth are often asymmetrically located. Incorrect placement of milk teeth is not considered a disease! Such a dental disorder has every right to exist until the complete closure of the dentition, that is, before the appearance of the first 16 teeth. Further, as a result of chewing food, milk teeth rub in and fall into place.

Change of milk teeth.

The change of milk teeth to permanent ones begins in babies at about five and a half years. Sometimes it happens a little earlier or later. The maxillofacial apparatus of the child is preparing for a change in milk teeth. You may notice that the gaps between the baby teeth have become larger - this means that the baby's jaw is growing, because more space is needed for the permanent teeth. If the intervals do not increase, permanent teeth can begin to grow crooked, so be sure to go to the doctor with the baby.

The process of changing milk teeth to permanent ones is interesting and not quite complicated. Some time before the loss of a milk tooth, its root gradually dissolves, the tooth begins to stagger. As the root of the milk tooth is resorbed, it staggers more and more until it falls out. Simultaneously with resorption, the permanent tooth grows slowly. Sometimes the milk tooth falls out on its own, often children loosen them and pull them out on their own. The root of the new tooth is not yet fully formed. This will take at least two to three years.

In order for the roots of the permanent teeth to form strong, and for the health of the teeth themselves, a sufficient amount of calcium should be introduced into the child’s diet.

The timing of changing teeth is very individual, but the sequence of this process is always the same. The first permanent teeth that you find in your baby's mouth are molars - the sixth teeth in a row, if you count from the middle of the jaw. A place for these teeth will appear when the jaw grows, while the appearance of sixth molars is not associated with the loss of milk teeth.

Further, the change of milk teeth to permanent occurs according to the same scenario according to which milk teeth appeared. The incisors begin to stagger and change - first two in the upper and lower jaw, and then two more. After that, the premolars change - the teeth that are located behind the canines. The change of the first premolars falls at the age of nine to eleven years, then the second premolars should change before the age of twelve. Until the age of thirteen, the canines are replaced, behind them, at the age of fourteen, second molars appear (they also grow in empty places formed as a result of the growth of the jaw). The last to appear are the third molars, the so-called wisdom teeth. This happens after fifteen years. By the way, an increasing number of young people do not find these teeth. In fact, modern people no longer need them, and nature solves this issue.

Usually, changing milk teeth to permanent ones does not require any intervention of dentists. It happens quite painlessly. But there are cases when the permanent tooth is already visible, and the milk one does not even stagger. This situation threatens the child with the fact that the permanent tooth will grow crookedly and later it will be necessary to put braces to align it. Therefore, if you notice something like this in your baby, immediately go to the dentist. The milk tooth will be removed, and then the process will proceed as expected.

All newly minted parents are looking forward to the first teething of their children. But if they do not erupt in the established norms by doctors, in this case, adults begin to sound the alarm and worry about the kids. These fears are quite logical, since timely teething is a sign of normal development of the child.

Also, these experiences can occur when replacing primary teeth with molars. Against this background, many questions arise: what is the timing of the eruption of the first teeth and their replacement with molars? What teeth and at what time are cut in children, to what age do the main teeth climb, in what order do they appear, how many should a child have up to one year old?

Symptoms and timing of teething in children

The first symptoms of eruption are increased salivation, which is necessary to disinfect the oral cavity, a slight swelling of the gums, the child's fingers and toys are in the mouth all the time.

Many parents indicate the appearance of a high body temperature, chills and loose stools, however, these are the signs it is not necessary to determine teething, since this process cannot cause such symptoms. Most likely this is an infectious disease that can easily affect a child due to weak immunity during eruption.

In what order does the cut take place?

Quite often, young mothers are interested in what is the correct sequence of teething in babies up to one year old. No doctor will be able to tell the exact time of eruption, since everything happens in any baby individually. But still there are two basic rules that determine the order of teething:

"Lower revolution". The natural teething system in babies under one year old implies that the lower teeth are cut first in any case, and only then the ones of the same name sprout from above. Naturally, this rule has an exception regarding the eruption of the lateral incisors (upper ones first grow, then lower ones);
Pairing. Teeth of the same name, as a rule, cut through almost simultaneously. If the upper left incisor grows, then very soon one should expect the germination of its right counterpart. In some cases, babies may have multiple teething.

Even in spite of the time established by doctors for eruption, adults most often rely on the practical time of their germination:

Lateral incisors;
Upper and middle lower incisors;
Fangs;
First molars;
Second molars.

In some babies, upper eruption may begin. Sometimes this is a sign of rickets, but, as a rule, this is an individual feature of the growth and development of the child.

There may also be cases when there are already several teeth on top, and not even any symptoms of early germination appear at the bottom. Do not worry too much in this case, if during the examination the pediatrician did not identify any violations, then the child will certainly acquire missing teeth in the near future. It's just that this process will take a little more time and, most likely, you will need to increase the amount of consumed products with calcium (milk, sour cream, etc.). It must be remembered that the drawn up diagram and growth table is only an approximate, and not an exact rate of eruption.

Growth time

Most often, only a born child does not have teeth, but sometimes there may be cases when teething in babies resembles even in the womb and he is born with several teeth. As a rule, the first teeth in babies up to one year old grow in pairs with an interval of several months. The middle lower incisors usually grow first, this happens at the age of 7–8 months, then the middle upper incisors appear.

Approximately by a year, the upper lateral incisors are shown, and after a short time, the lower ones. In about a year and a half, the first molars appear, then fangs, and when the baby is about two years old, second molars appear.

At this stage, the formation of a milk bite is completed, there are only 20 milk teeth in children. Replacement of milk teeth with molars begins most often at the age of about 5–8 years.

Growth not by the rules

The growth retardation can be explained from a genetic point of view or the time of birth of the child. For example, babies born in winter acquire milk teeth at a fairly early age. But if at the age of one year they never sprouted, then you still need to play it safe and consult a dentist, since such a delay may indicate a problem with metabolic processes or be a symptom of the development of rickets. But, when milk teeth are the only drawback of a happy and healthy child, then, probably, adults simply cause unnecessary panic and rather want to see the appearance of the first teeth in their baby.

It is also very important to immediately start taking care of them immediately after their appearance and teach your baby to constant cleaning. These activities will significantly increase the chances of keeping them healthy and beautiful.

Regarding the order or the same sequence of growth, in this case, too, everything goes on in an exclusively individual order and the order of teething can differ significantly from that generally accepted by doctors. Many dentists are confident that all moments of development are directly affected by the mother's lifestyle, her illness, pregnancy and childbirth itself.

But still, when a child's eruption is completely out of place, then you don't need to worry too much and escalate this situation. No one has yet made a drug that would make teeth erupt in a clear order, and when they fully grow, it will absolutely not matter in which queue they appeared.

What affects the growth of molars?

A number of factors can affect the timing of the change of milk teeth to molars:

Disruptions in the endocrine system;
Child gender;
The form of feeding and its duration;
Negative aspects of pregnancy (for example, toxicosis);
The genotype of the child;
Postponed infectious diseases;
Disruption of metabolic processes.

It is necessary to ensure that the time of the change in molars, which are indicated in the table or calendar, coincides with the schedule for the loss of all milk teeth. It often happens that dairy falls out much earlier than necessary time. This can occur as a result of mechanical deformation of bone tissue, due to malocclusion or excessive pressure by the indigenous.

The quick time of the loss of milk teeth is dangerous because those nearby begin to shift, thus filling the void that has appeared. As a result, by the time when it is time for the root, he simply does not have enough space and, most likely, he will be crooked.

In case of untimely loss, you need to go with the child to be examined by an orthodontist, if necessary, he will install the plates in order to prevent the displacement of the dentition.

In the case when the milk teeth do not want to fall out on their own at the right time, when the molars are already obliged to replace them, this is fraught with the development of an incorrect bite. It is imperative to visit a doctor to take the required measures. It is very important that adults pay attention to the age at which the teeth appeared in the child and how they are in the dentition. Since an incorrect bite can affect not only aesthetics, but, in general, has a significant impact on the health of the baby.

The line of molar germination

Teething in molars in children has a special order, which makes it possible to properly form a bite. When should they erupt, and what is their priority? For better understanding, the molars are numbered starting from the medial incisor.

According to the teething scheme, the first molars or lower sixes begin to appear first. The approximate age of the baby when they erupt is 5-8 years. It should be noted that these teeth do not change milk, but are immediately molar. The place for their germination is provided in advance due to the growth of the jaw itself. Then lateral middle incisors grow, after the first premolars, upper sixes, second premolars and canines. The full formation of molars is completed by adulthood.

Teething Features:

Brownish yellow enamel color most often associated with the use of antibiotics by the mother in the 2-3 trimester of pregnancy, or their use by the baby during eruption;
Incorrect row formation occurs for a number of reasons: a genetic predisposition (a very small jaw), a congenital anomaly in metabolic processes in connective tissue, trauma;
Spacing between teeth. This feature speaks about the active development of the jaws and during the interchangeable transition of temporary teeth to permanent teeth is regarded as a normal state. An enlarged gap (usually between the middle upper front teeth) appears due to the deep location of the frenum in the upper jaw. The orthodontist is engaged in the correction of this defect;
Malocclusion happens due to the long time of sucking the dummy or due to the abnormal development of the jaws;
Gray piping around the neck most often appears while taking soluble iron preparations or with severe inflammation;
Very rarely, teeth that do not appear by the age of one are symptoms of adentia - lack of primordia. It is possible to determine this diagnosis only with the help of radiovisiography.

How to care for your teeth?

It is necessary to start oral hygiene even during the introduction of complementary foods. Up to one year, this can be done with a soft toothbrush or tissue soaked in warm water.

Closer to the year you need to brush your child’s teeth at night without toothpaste with a special brush. It must be changed at least twice a month.

You can start using special children's pastes without fluoride from the age of two years.

Instill in your baby the feeling of the need for a periodic examination at the dentist for prevention at least once every 6 months. The first trip to the doctor must be carried out with the eruption of the first teeth, at the age of about six months.

Teach your child to brush his teeth twice a day, especially at night. In order to prevent the appearance of caries, which is so susceptible to milk teeth, you do not need to abuse excessive consumption of sweets and foods with a large amount of sugar.

During life, two different sets of teeth develop [ST]. The first shift serves in childhood, and the teeth forming this generation are called milk teeth. They gradually fall out and are replaced by permanent ZB, which remain with a person for the rest of his life.

In the first shift, there are 20 ZBs: 10 each in the upper and lower jaw. At the age of 6-7 months, the first two lower middle incisors erupt, at 7-8 months - two opposite upper incisors. Then, at 8-9 months, two more upper incisors are cut through, and during the last quarter of infancy, two lower incisors are cut through. Thus, by the end of the first year of life, a healthy child should have eight teeth. By the age of two, the first milk molars and canines erupt. Second milk molars appear after another six months. The complete formation of the milk dentition is usually completed in three years. This set of STs serves the baby for the next 4 years, after which the milk STs drop out and are replaced by permanent ones. plywood buy price per sheet

Like other development indicators, teething times have individual characteristics, therefore, even in healthy children, their later teething is possible later (or less commonly). However, a significant delay in tooth growth is a symptom of a baby’s disease, most often rickets. In rare cases, children have adentia - the absence of tooth rudiments. You can check for the presence of dental germs using an X-ray. X-ray irradiation can be unsafe for the child's body, therefore this study should be performed only when necessary and as directed by a doctor. Today it is possible to reduce the harmful effects of X-rays if you take a picture with a radiovisiograph. Such equipment is usually available in every modernly equipped dental clinic.

The change of milk STs lasts from about 6 to 12 years. The set of permanent STs consists of 32 - 16 upper and 16 lower. They are similar in shape to dairy ones, but are larger in size. Two germ layers are involved in the formation of ZB. Enamel develops from ectoderm, dentin, cement and pulp from mesenchyme.

The development of primary teeth includes several periods:

Formation and formation of tooth germs

(early stage of development) - the beginning of 6-7 weeks of intrauterine development (Fig. 1).

Fig. 1.

Bookmark the rudiment of a milk tooth

1 - oral epithelium, 2 - dental plate, 3 - enamel organ, 4 - dental papilla.

It begins with immersion of the epithelium of the oral cavity into the underlying mesenchyme in the form of a dense strand (dental plate). Small epithelial protrusions called dental primordia appear on the tooth plate, of which (10 from below and 10 from above) will develop a milky ST. As the dental plate grows, each tooth germ increases in size, penetrates deeper into the mesenchyme and takes the form of an inverted bowl. This structure forms the enamel organ, and the underlying mesenchyme filling the cavity of the bowl is called the dental papilla.

· Differentiation of tooth germs

3 months of intrauterine development.

The enamel organ increases in size, changes shape and gradually separates from the dental plate. The cells of the tooth primordium actively proliferate and differentiate into internal, external and intermediate. The internal epithelium consists of high prismatic cells forming an enamel, hence their name - enameloblasti (enameloblasti). The outer epithelium in the process of growth of the enamel organ is flattened, with the eruption of the ST it merges with the epithelium of the gum and is further destroyed. The intermediate enamel epithelium acquires a star shape due to the accumulation of fluid between the cells and forms the pulp of the enamel organ, later the pulp takes part in the formation of the cuticle (thin and dense shell) of the enamel. The mesenchyme surrounding the ST bookmark and the dental papilla is compacted and forms a tooth sac. By the beginning of 5 months, the enamel organ loses its direct connection with the epithelium of the oral cavity, although the remnants of the dental plate can persist for a long time (sometimes cysts develop from them). Shortly before this, the cells of the dental plate form a second epithelial anlage, from which a permanent ZB will develop.