Upper molars. What teeth are called molars and premolars, anatomical features. Features of the structure of the lower and upper molars

Greetings, dear readers! When a baby's teeth are cut, it is always painful and unpleasant. Parents suffering from a child cause a lot of trouble. And when it seems that this painful period is over, new "guests" make themselves felt. Let's look at: molars are what kind of teeth, and what are the symptoms of their appearance.

Molars in children

Most parents think that all teeth in young children are milk teeth. Subsequently, they fall out and are replaced by indigenous ones. But it is not so.

The first indigenous units of milk bite are molars. They have the largest chewing area. From above, they are diamond-shaped in shape, from below they resemble a cube. Children have 8 molars - two on each side below and above. Separate the first molar and the second molar. According to the account from the central incisors, they occupy the 4th and 5th position.

Their cutting order is as follows:

• the first in the lower jaw - 13-18 months;
• the first in the upper jaw - 14-19 months;
• the second in the lower and upper jaws erupt approximately the same - at 23-31 months.

Already after a year, parents should prepare to meet these “guests”: the first one will climb in the top row. By the age of two, the second ones erupt. The correct sequence of appearance ensures a beautiful and correct bite.

Many parents like to look into their babies' mouths and check how their teeth are climbing. Do not do this and once again worry the crumbs. Genetics play an important role in this process. No need to interfere: nature will take care of everything itself. To find out what chewing units look like, a photo of molars will help.

To help the child and alleviate his condition, it is very important for parents to know what the symptoms of teething are. Since the process occurs after a year, many children can already point out a sore spot and even say what they feel.

Signs of eruption are the following sensations:

Profuse salivation

If by the age of two this sign is not too noticeable, since the baby can already control itself, then in the year when the first chewing unit is preparing to crawl out, the bib may be all wet from flowing saliva. The symptom worries about 2 months before eruption.

whims

Anxiety, whims, disturbed sleep and appetite. If the baby is still breastfeeding, the mother may notice an increased need for lactation.

Temperature

Elevated temperature. Appears a couple of days before the eruption of the first white strip in the gum. Sometimes the temperature can reach high rates - 38-39 degrees. At this time, it is important to understand that this is a sign of an erupting tooth, and not a viral or infectious disease.

Reddening of the gums

Swelling and redness of the gums. If this happens, expect a "guest" in 2-3 days.

Cold symptoms

Often, the appearance of dental units is accompanied by more serious symptoms:

• diarrhea
• conjunctivitis;
• runny nose;
• otitis.

Each baby has these symptoms.

Readers are probably interested in whether or not the chewing units of the milk bite fall out. Of course they fall out. In their place, indigenous ones appear, which remain with a person for life.

Molars and premolars in humans

Replacing the milk bite with indigenous units occurs in the following order:

• The first molars appear between the ages of 5 and 8.
• At 10-12 years old, the first and second premolars are replaced.
• The second appear from 11 to 13 years.
• Third, or wisdom teeth, occur in adulthood from 16 to 25 years.

Doctors have noticed that recently wisdom teeth have rarely erupted. They remain hidden in the gum cavity. In ancient times, they were designed for active chewing of solid food. In modern man, such a need has disappeared, therefore, third chewing pairs become a relic.

Signs of eruption of permanent teeth

• The main sign of eruption is trema - the gaps between the dental units. They are necessary in order to make room for new "tenants". If there are no trems, the teeth begin to fight for space and overlap each other. As a result, the bite is disturbed, and the child must be taken to an appointment with an orthodontist.
• Another sign is the gradual loosening of milk units. The roots gradually dissolve, loss occurs. The process is sometimes accompanied by high fever, loss of appetite, irritability.

The correct and timely appearance of molars is extremely important for the health of the baby. This process must be carefully monitored and in case of abnormal development, contact the dentist.

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In what order do milk teeth hatch?

The rudiments of teeth are formed in the womb. A newborn has 20 follicles located in the lower and upper jaw, it is from them that milk teeth develop.

The cutters are the first guests in a small state

They are located in the lower and upper jaws, 2 central and 2 lateral in each. Teething begins with the central lower incisors at the age of 5-6 months. The top leaves 1-2 months later.

The child also has 4 lateral incisors, they are located near the central ones. The upper ones erupt when the child reaches 9-11 months of age, the lower lateral incisors appear a little later, from 11 to 13 months.

Indigenous people follow them

Another name for these milk teeth is molars. They are divided into first and second.

The first molars are located near the canines in both jaws, there are 4 of them. They appear in a child no earlier than at 12-16 months.

The second milk molars come out the latest, this process is observed after two years. They are located behind the first (small) molars.

When will the fangs come out?

Their turn comes when the baby is 16-20 months old. They are located in front of the first molars. During this period, it is necessary to try to prevent the development of colds, since fangs often cause a deterioration in the health of the baby.

This order of eruption of milk teeth in children is considered a classic. It is also possible that they appear a few months earlier or later than the above dates.

This is also the norm. In medicine, even cases are known when newborns already had milk teeth.

Teething Formula

It is very simple to determine the number of milk teeth in a child; you need to subtract four from his age, taken in months. The result obtained will indicate their number. For example, if the child is 11 months old, then according to the formula, he should have 11-4 = 7 teeth. This formula is valid up to 2 years.

The order and timing of eruption of permanent teeth

The beginning of the eruption of the first permanent teeth should be expected before the first milk teeth fall out. In order for the child to form the correct bite, they erupt in pairs and in a certain order:

Possible problems

The above terms of teething are the norm. But under the influence of certain factors, problems associated with this process may arise.

Adentia

You can talk about it in the absence of one or more teeth and their rudiments. The diagnosis is established not earlier than 10 months of age. The cause may be heredity, problems with the endocrine system, concomitant diseases of other organs.

Signs of adentia are:

• malocclusion;
• violation of diction;
• missing one or more teeth;
• large gaps between teeth;
• sunken cheeks.

If there are rudiments of teeth, then the doctor prescribes a treatment that will stimulate eruption. Sometimes the gums are cut or special braces are installed. In their absence, implants are used.

retention

With this pathology, there is a tooth germ in the gum, but it does not erupt for two reasons:

• too dense gums;
• the tooth at the exit rests against the previously erupted tooth.

It is manifested by soreness, edema, hyperemia, fever. Treated by cutting the gums or removing the impacted tooth.

Early teething

The appearance of the first teeth before 4 months of age is considered early. This often happens with disorders in the endocrine system, it can also indicate the presence of tumors.

Late teething

We can talk about this problem if teeth are missing at the age of 10 months. This leads to a lack of calcium, genetic predisposition, violation of enzymatic metabolism, pathology of the digestive system, rickets and other factors.

If by the age of 1 the child has no teeth, show the baby to the dentist.

Breaking the order

Occurs when the teeth appear in the wrong order. It can lead to ingrown teeth into the gums and the formation of a malocclusion.

Enamel hypoplasia

It develops with the inferiority of the enamel. Externally manifested by the presence of grooves, pits, roughness on the surface of the teeth. The child complains of pain when taking cold or hot food.

Treatment consists in the exclusion of harmful factors, the placement of fillings or prostheses.

How can you tell if your baby has teeth?

A small child cannot tell the reason for his anxiety. But during the appearance of teeth, the following changes in its condition can be noticed:

• increased secretion of saliva;
• swelling and redness of the gums;
• weakness, crying, anxiety;
• refusal of food;
• the child gnaws everything that comes to hand;
• a slight increase in temperature is possible.

The photo shows how the gums look when teething in babies:

What and how to alleviate the condition of the child?

It is impossible to completely avoid the symptoms of teething, but you can alleviate the condition of the baby:

• use chilled teethers, they will relieve swelling and reduce pain;
• you can also massage the gums finger, after washing your hands well;
• use to reduce pain anesthetic gels;
• provide sufficient consumption of foods rich in calcium;
• in time wipe your saliva to avoid irritation to baby's delicate skin.

Milk teeth care

It is necessary to begin to carry out oral hygiene with the introduction of complementary foods and the appearance of the first tooth. Up to a year, this can be done with a napkin dipped in boiled water or with a soft toothbrush.

Closer to the year, brush your baby's teeth before going to bed without paste with a special toothbrush. It needs to be replaced at least once every 3 months.

You can start using children's toothpaste without fluoride from the age of 2.

Teach your baby to brush his teeth 2 times a day, it is especially important to do this before bedtime. To prevent the development of caries, and milk teeth are especially susceptible to it, you should not abuse sweets and foods with a high sugar content.

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Symptoms

There are symptoms by which you can find out that a child is teething, and respond to this with timely help, alleviating his condition. Signs can be basic, caused directly by this process, and accompanying - dictated by other factors, but coinciding in time with this phenomenon.

Main

It is the main symptoms that will tell parents how to understand that a child is teething:

• swelling, swelling, itching of the gums;
• bad sleep;
• Why does a child eat poorly when teeth are being cut? - lack of appetite due to pain when touching swollen, inflamed gums;
• how is the child behaving? - he is irritable, aggressive, naughty, often and a lot of angrily cries, takes everything in his mouth to relieve itching;
• increased salivation;
• rash, redness around the mouth, on the chin.

Here are some symptoms in a child when teeth are being cut, you need to pay attention. Together, they give a clinical picture of this natural physiological process. However, they are often accompanied by accompanying manifestations that indicate other health problems. But unknowing parents mistakenly attribute them to teething.

Related

The question of whether children get sick when teeth are cut is due to the fact that the main symptoms can be supplemented by a number of accompanying ones, which may indicate some diseases that coincided with this process. You need to know about them in order to see a doctor in time and undergo treatment - this will significantly alleviate the condition of the baby.

• Temperature

What could be the temperature? Normally, it should not exceed 37.5 ° C, since the gums only slightly inflame during teething. If the mark on the thermometer shows more than 38 ° C, this is a sign of SARS, viral herpetic stomatitis or intestinal infection - an urgent consultation with a pediatrician is needed.

• rashes

Bubbles filled with a cloudy liquid, erosion, bright red hyperemia, inflammation on the mucous membrane of the mouth and gums are symptoms of herpetic stomatitis.

• loose stool

What is the child's chair when teething? Normal is normal. But if it becomes liquid, accompanied by vomiting and high fever, it is a rotavirus infection. Single vomiting without other symptoms is a consequence of swallowing a large amount of saliva.

• Cough

A cough occurs when a child chokes on saliva that enters the respiratory tract instead of the esophagus. Or it is a symptom of a disease associated with the lungs or throat.

• Runny nose

A runny nose indicates a cold and has nothing to do with teething.

In those days when children are teething, parents should be as attentive as possible to any changes in their condition and be able to distinguish the main symptoms from the secondary ones. This will help not to start a concomitant disease that can disguise itself as a natural process, and help the baby survive this difficult period.

It is interesting! Take a look at your baby's teeth. Solid, durable - a sign of an energetic person; large - kind and open; small - petty and scrupulous.

Subsequence

In addition to the main symptoms, it is useful to know in what order the teeth come in in order to expect them to appear in the right place. This will be needed when using compresses and ointments. And it turns out that they cooled one, seemingly swollen, area, and the incisor or canine appeared in a completely different one.

1. Six months-8 months - lower central incisors.
2. Six months to a year - the upper fangs.
3. 8 months-year - upper central incisors.
4. 9-13 months - upper lateral incisors.
5. 10 months-1.5 years - lower lateral incisors.
6. 13-19 months - upper molars.
7. 1.5-2 years - lower fangs.
8. 1-1.5 years - lower molars.
9. 2-2.5 years - lower second molars.
10. 2-3 years - upper second molars.

Parents should also keep in mind which teeth are cut the most from this list. The fangs, with their sharp edges, tear the gums most painfully, thereby causing severe pain to the child. Especially the upper ones, which are called "eye teeth": they are connected with the facial nerve. And, of course, you need to keep in mind the timing of when to expect all this and how long the whole process will last.

Curious fact. When one of the identical twins is missing a tooth, most often the exact same one is missing from the other.

Timing

Knowing the approximate dates when certain teeth should be cut in a baby allows parents to prepare for this phenomenon. If he began to act up and refuse to eat, drool and not sleep, you should not immediately run to the children's clinic - in such a situation, you can provide first aid on your own.

• Age

According to the list given a little higher, you can see at what age the child's teeth are cut - from six months to almost 3 years. This is an individual indicator, and it can be shifted by several months. If there are significant deviations from the schedule and this process does not fit into the time frame indicated above, it is necessary to consult a doctor. Not so much a pediatrician as a pediatric dentist will help here.

• Duration

Parents often ask how many days children teething to know when relief comes. This is again very individual. On average, from 2 to 7 days - this is considered the norm. But the process can take several weeks. This is extremely rare, the situation is taken under the supervision of a doctor, the reasons for such a long process are being clarified.

Until what age do children cut their teeth? The main (20 dairy) should appear before 3 years. The rest of the indigenous - much later, from 6 to 8 years.

• First tooth

In the same way, you can answer the question of how many days the first tooth is cut: there is no reason to believe that it will climb longer or faster than the others. Hope for a few days, but always be prepared for a longer process.

The timing of teething in children can be different, which is determined by the individual characteristics of the body. Everything goes much easier and easier if they are not tightened. However, there is one consolation here: even if this whole process lasts for several weeks, its symptoms are not as pronounced as with a quick (2-3 days) eruption. The child usually behaves much calmer in such a situation. But in any case, parents should be aware of exactly how they can alleviate his condition.

Blimey! In terms of strength, human teeth can only be compared with shark teeth.

What to do

The first question that worries all parents is how to help when a child is teething. This applies to those situations when he is exhausted from pain and cries incessantly. To correct the situation will help various means - medication and folk.

Medicines

• Viburcol (Viburcol)

Don't know how to ease the pain? Use for this purpose homeopathic suppositories based on herbal ingredients, which have a calming, analgesic and slight antipyretic effect.

• Panadol Baby (Baby Panadol)

Parents should know what to do if their child has teeth and fever. First of all, call a doctor who will determine the cause of the fever and prescribe the appropriate treatment. And before his arrival, you can give Panadol - one of the most popular and effective drugs. The main ingredient is paracetamol. Candles are used for babies, syrup - after a year.

• Nurofen (Nurofen)

Looking for something to anesthetize a torn gum? Use Nurofen, an almost instantaneous antipyretic and analgesic suspension. It has a long-lasting effect (up to 6-8 hours). Contains ibuprofen. Not recommended for long term use.

• Gels and ointments

Pain-relieving ointments and gels are popular when children start teething, but this is not a very good choice. With copious salivation, they are quickly eliminated from the mouth, so that the duration of their effectiveness is very short. Feeling local numbness of the gums under their action, the child may choke or bite his tongue. These drugs include Holisal, Dentinox, Kamistad, Kalgel, Dentol, Baby Doctor, Pansoral (Pansoral), Traumeel (Traumeel) - this is exactly what to smear the gums in this situation.

Folk remedies

Wrap a piece of ice in a sterile cotton cloth, wipe the swollen gums without pressure.

If the child is not allergic to honey, rub this product into the gums before going to bed.

• Chamomile

Do not know how to calm a child who is tormented by pain? Let him drink small amounts of chamomile tea 2-3 times a day. You can apply a compress to the gum - a bandage soaked in a decoction of chamomile. With the oil of this medicinal plant, you can lubricate the cheek from the outside where it hurts.

• Chicory root

Give the child a chicory root to chew (can be replaced with strawberry root).

• Propolis

Lubricate the inflamed gums with propolis infused with water.

• Mummy

Wipe the gums twice a day with a mummy solution.

• frozen fruit

If the child is already on complementary foods, you can give him to gnaw on small pieces of frozen fruits - a banana, an apple, a pear.

• bread products

Bagels, crusts of bread, cookies, crackers can scratch itchy gums.

Care

1. Before the appearance of teeth, clean the gums in the morning and evening with a clean bandage wound around a finger and soaked in boiled water.
2. Can I bathe my baby while teething? In the absence of high temperature - it is possible. If it is, it is better to limit yourself to rubdowns.
3. Apply children's anti-inflammatory toothpastes, gels, foams: Weleda, Splat, Splat, Lacalut, Lallum Baby, President, Brush-baby, Silver Care (with silver), Umka, R.O.C.S., Silca, Elmex.
4. Don't give too many sweets.
5. Learn to chew vigorously.
6. Include more fruits and vegetables in your diet.
7. Visit the dentist 2 times a year.

Now you know how to help a child with folk remedies and medications. All of them do their job very well. If you are unsure of their use, consult your pediatrician or dentist. From now on, you will need to visit the latter's office regularly to avoid complications.

Scientific data. The tooth is the only tissue that is not capable of self-healing.

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Premolars

Premolars are small molars. They are located behind the fangs, because of this they have some similarities with them. However, they share some of the characteristics of the large molars behind them. Allocate upper (first, second), lower (first, second) premolars.

Upper premolars

Outwardly, they have a prismatic shape, their sizes vary from 19.5 mm to 24.5 mm, usually in most people their length reaches 22.5 mm. Most often, the first or second premolars of the upper jaw are slightly larger than the lower ones. This is what an upper premolar looks like:

On the chewing surface, small tubercles are clearly distinguished, with large buccal and smaller chewing tubercles, between which there is a small furrow. The first premolar of the upper jaw has two dental roots, similarly, the second one following it.

lower premolars

The lower premolars have some differences among themselves. The first tooth is anatomically similar to the adjacent canine. It has a rounded shape, as well as in the upper premolars, lingual, buccal tubercles are revealed on its surface, and a groove is located between them.

Premolars are permanent teeth. In children, they are not part of the bite. The first premolars appear after nine to ten years, the second a little later, at eleven to thirteen years.

molars

Large molars or molars, what is it? Normally, an adult should have twelve of them. Arranged in pairs, six at the top and six at the bottom (three each on the left and right). They are sometimes referred to as "posterior" due to the fact that they are located last in the dentition.

The main function is chewing food. Perhaps that is why they have the largest sizes, especially for the upper coronal part. They also have a large chewing surface. Thanks to such anatomical features, they can withstand loads up to 70 kg. Usually the upper molars are slightly larger than the lower ones.

Molars are what teeth? There are first, second, third upper, as well as first, second, third lower molars.

Upper large molars

The dimensions of the crown part are 7.0-9.0 mm. The upper chewing surface is divided by pepper grooves into four small tubercles. There are three roots: bucco-mesial, palatine, and also bucco-distal.

This is what an upper molar looks like:

The third molar, the eighth tooth, is smaller in most people than the others, and sometimes may be completely absent. Its upper surface has a three-tubercle structure, less often two or four tubercles are detected. It usually has three roots, just like the previous large molars, two buccal, one palatine. The number of roots may be somewhat larger, sometimes up to five.

Quite often there is an abnormal location of the figure eight, its retention (lack of eruption), deviation towards the cheek. A special and rare case is hyperdontia, the presence of a fourth molar that is mostly incompletely formed.

Lower large molars

In the lower molars, the size of the crown part is slightly smaller than in the upper molars. On the chewing surface, several tubercles are usually found, their number varies from 3 to 6. The 2nd large molar rarely has five tubercles, usually their number is four.

These teeth have 2 roots, distal and medial. They are located parallel to each other. The figure eight has one or two dental roots. Sometimes there is its retention, displacement to the side.

Molars in children

In children with a milk bite, the first and second molars are distinguished. The second molars in children erupt somewhat later than the first. The timing of their eruption is as follows:

• 1st top after 14 months
• 1st bottom after 12 months
• 2nd top after 24 months
• 2nd bottom after 20 months

The replacement process consists in the resorption of dental roots, as well as adjacent areas. At the same time, growing permanent molars displace their predecessors. The first molars in children appear first of all, they are clearly visible in the lower dentition in the photo:

The periods of change of bite are as follows:

Upper molars

• 1st - 6-8 years
• 2nd - 12-13 years old
• 3rd - 17-21 years old

lower molars

• 1st - 5-7 years
• 2nd - 11-13 years old
• 3rd - 12-26 years old

Usually, permanent teeth in a child, in particular, molars, erupt painlessly, without an increase in body temperature. Sometimes there are problems with the appearance of "wisdom teeth", which is associated with their abnormal location, as well as a tendency to form caries.

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Anatomy

The upper and lower gums are equipped with three types of teeth. Anterior incisors. Immediately behind the incisors are the fangs of the child. Behind the canines are two sets of molars, the first and second molars. They are usually cut very painfully.

Beginning and duration of molars eruption

Every child is different, so there is no universal guideline for how long it takes for molars to fully emerge. There is an average time range that can help you judge your child's situation. The upper and lower molars of a child are cut at the age of 12 to 17 months. In any case, they will appear between the ages of 27 and 32 months. Upper second molars begin to erupt between 24 and 33 months and complete eruption between 38 and 48 months. The second lower molars begin to appear between 24 and 36 months and these molars in a child will be cut between 34 and 48 months.

Symptoms that your child is teething

Teething in children is not a walk in the park for you or your child. The first sign that your baby is teething may be a change in mood. Your child becomes more irritable and begins to experience interruptions in sleep. If you look into his mouth, you will see red and swollen gums near the area where the molars begin to grow. How long these molars are cut in a child depends on many factors, including hereditary ones.

Why does a child's molars take a long time to cut?

Molar teeth may take longer to erupt than other teeth. A child's molars take a long time to cut because they have a large surface area that needs to be freed from the gums. This not only increases the timing, but also makes the eruption of the molars in a child more painful than the eruption of the incisors.

Help when teething in children

Some children will experience quite severe discomfort when their molars are cut - this is pain, poor sleep, lack of appetite, increased salivation, nervousness. By the way, sometimes, suddenly waking up with teeth, they can be very surprised and, accordingly, psychologically unstable.

Children produce large amounts of mucus as a natural reaction to any oral irritation. This mucus can become a breeding ground for bacteria and viruses, so teething times can make a baby a little more susceptible to colds. Chamomile tea and clove oil are known for calming nerves and soothing gums. In addition, affordable immune support can be provided to children, such as colostrum and vitamin D3.

Baby's discomfort can be alleviated by offering to chew on something cold, such as a chilled teething ring, or a damp, cool one. With the approval of your doctor, use paracetamol or ibuprofen, which will greatly relieve pain during molars.

Most moms and dads believe that molars are permanent teeth that are replaced.

In fact, molars are both temporary and permanent.

The first inhabitants in the oral cavity

Therefore, you don’t really need to worry if the tooth erupted earlier or a little later than the due date. But it is worth paying attention to the order in which the teeth erupted and fell out, since there is still an approximate order in which the teeth appeared.

Signs of the appearance of molars

The eruption of molars in children is accompanied by unpleasant symptoms. As a rule, it is the first molars that give the child the most trouble.

He experiences pain, becomes capricious and irritable, sleeps poorly, refuses to eat, or vice versa often requires breasts.

The gum at the site of eruption swells and itches, the child tries to tighten everything into his mouth. A special one can help the child during this period, as well as rubbing the gums with a bandage dipped in cool water. As prescribed by the doctor, the gums can be lubricated with an analgesic gel.

Baby teethers

The process of molars eruption usually lasts 2 months, all this time the baby has increased salivation.

To avoid irritation of the skin of the chin, it must be constantly wiped and lubricated with a protective cream. The child may rise, appear, runny nose and wet cough.

Moreover, the temperature can manifest itself not only during the eruption of the first molars of milk teeth, but also with the appearance of permanent molars, when the child is 9 to 12 years old.

This is understandable: when the gums swell, blood flow increases, biologically active substances begin to be synthesized in the body, the main task of which is to eliminate swelling and eliminate pathology. In other words, the body reacts to the appearance of teeth as a disease, resulting in a rise in temperature.

At a high temperature, the doctor may prescribe antipyretic drugs based on Paracetamol or Ibuprofen to the child, which, moreover, will also eliminate the pain syndrome.

How permanent teeth erupt in children - timing and scheme

Dairy VS permanent

Many people think that only a permanent tooth has a root, while a temporary one does not, because of this it easily falls out. This opinion is erroneous, everyone has both a root and nerves, and they have a more complex structure than permanent ones, so they are more difficult to treat.

Temporary teeth are less mineralized, they are smaller in size, have a bluish tint, are softer, their roots are weaker. In addition, there are only 20 of them, while there are 32 permanent ones, if a person has not erupted "wisdom" teeth, then 28.

When the time comes for the temporary tooth to fall out, its root will resolve, and its crown either falls out by itself, or is quickly and painlessly removed by the doctor.

Permanent indigenous - when do they appear?

A permanent bite begins to appear from 5-6 years to 12-15, usually during this time a lot of dentition comes out, although in some they erupt only after 30, and in some they do not exist at all. They grow in the same order in which they fall out.

It is necessary to control the process of the appearance of permanent molars, in the case when they erupt 3 months later in time, this may indicate a serious pathology, for example, a metabolic disorder, vitamin deficiency or rickets.

This diagram of the eruption of permanent teeth in children is indicative. But the sequence of appearance of teeth in the absence of pathology should be constant.

From the beginning, when the baby is 6-7 years old, the first permanent molars (the “six” molars) will erupt behind the entire milk row. They will appear in a place where milk teeth never grew. Then temporary teeth are replaced by permanent ones, exactly in the same order as they erupted.

First, two incisors are changed on both jaws, then two more. After them, small molars (“fours”) or premolars erupt.

They change when the child is 9 to 11 years old, the second premolars or "fives" should erupt before the age of 12. Until the age of 13, fangs erupt.

Following them, in an empty place at the end of the dentition, the second large molars (“sevens”) erupt. They change until the age of 14.

The last to erupt are the third molars, the "eights" or "wisdom teeth". In some, they appear before the age of 15, in others much later, in others they may not be at all.

What are they like on the inside?

Permanent molars are divided into small (premolars) and large (molars). An adult has 8 small molars, located 4 above and below. Their main function is to crush and crush food.

They appear in place of the fallen milk molars. Premolars combine the features of large molars and canines.

They have the shape of a rectangle, on the chewing surface there are 2 tubercles separated by a fissure. The small molars of the upper jaw are similar in shape, but the first premolar is slightly larger than the second and has 2 roots, while the second has only one root.

The lower premolars are rounded, each of them has 1 root. They differ from each other in size: the first premolar is slightly smaller.

Large molars grow behind the second premolars. There are only 12 of them, 6 pieces on both jaws. The biggest "six". The upper first and second molars have 3 roots, the lower "sixes" and "sevens" have 2 roots.

The structure of the third upper and lower molars ("") differs from each other both in shape and in the number of roots. Some don't have them at all. Very rarely, as a rule, among representatives of the eastern equatorial race, additional fourth molars are found.

Out of my head…

If a permanent one has hatched at the site of a temporary tooth, and the milk one is not going to fall out yet, then the doctor will advise you to remove it.

In the upper area, displacing the anterior buccal, the longitudinal axes of the odontomeres have a different direction towards the central fossa, and the location of the first-order sulcus is shifted to the buccal side.

If the process of reduction - differentiation in the region of the upper molars is significantly expressed, then the shape of the crown can change significantly, however, the mesiodistal parameter still prevails over the vestibulolingual one (Fig. 300-304).

The location of the tubercles along the surfaces of the crown also changes: the 1st order furrow transforms from an H-shaped into an X-shaped one.

The degree of differentiation of the main tubercles is significantly increased, while additional formations appear that give the surface of the tooth a bizarre pattern, furrows of 1, 2, 3, 4 orders are visible.

The variability of the forms of the upper molars is also manifested in a decrease in the size of the posterior palatine tubercle, or in its complete absence (classification by A. Dahlberg). Rice. 305, 306 show the chewing surface of the crown of tooth 17, which has a triangular shape, where the posterior palatine tubercle is completely absent.

Let us analyze in more detail the structure of the upper left second molar.

The chewing surface of the 27th tooth is demonstrated (Fig. 307, 308). The chewing surface of the upper left second molar resembles a diamond shape, where the mesiodistal crown parameter exceeds the vestibulolingual one.

Rice. 307-308. A - distal side; B - medial side; C - palatal side; D - vestibular side; 1 - mediovestibular or anterior buccal tubercle, paraconus (par); 2 - distovestibular or posterior buccal tubercle, metacone (te); 3 - mediopalatinal or anterior palatine tubercle, protoconus (pr); 4 - distopalatinal or posterior palatine tubercle, hypocone (hy); 5 - additional medial tubercle; 6 - additional distal tubercle; 7 - vestibular groove; 8 - medial furrow; 9 - central furrow; 10 - distolingual or distopalatinal, or posterior palatine sulcus; 11 - distal triangular fossa; 12 - central fossa; 13 - transverse anterior furrow

When conducting odontoscopy, the presence of 4 main tubercles - odontomers is noted:

1 - mediavestibular or anterior buccal tubercle,

2 - distovestibular or posterior buccal tubercle,

3 - mediopalatinal or anterior palatine tubercle,

4 - distopalatinal or posterior palatine tubercle.

Each of the odontomere tubercles is bounded by a groove:

7 - vestibular groove separating the anterior and posterior buccal tubercles;

8 - medial groove separating the anterior cervical and anterior palatine tubercles;

9 - central furrow separating the main tubercles;

10 - distolingual or distopalatinal, or posterior palatine, separating the posterior palatine tubercle from the main tubercles.

Similar to the structure of the first molar, three main tubercles are distinguished on the chewing surface of the second molar (anterior buccal (1), posterior buccal (2), anterior palatine (3)), which, when combined with each other, form a trigon (triangle).

The distal palatine tubercle (4) occupies the talon (heel). When examining the chewing surface of the 27th tooth, in addition to the main tubercles, two additional tubercles are visible (5, 6).

Additional medial tubercle (5) is formed as a result of branching of the medial sulcus (8), the main trunk of which cuts through the medial marginal ridge, and also gives a fairly deep and extended branch in the vestibular direction, tending to the top of the anterior buccal tubercle (anterior transverse sulcus - 13).

The accessory distal tubercle (6) forms the distal contact surface and the posterior triangular fossa (11). The highest of the odontomeres of the upper second molar is the anterior buccal cusp (1). It is advanced in the medial-vestibular direction, in connection with which the chewing surface of the crown acquires a rhombic shape.

On its surface, a longitudinal ridge is defined with a pronounced apex, smooth slopes, tending and falling into the medial fissure.

The medial ridge is not expressed. The distal roller is determined, the crest of which descends to the vestibular sulcus. There is a slight depression between the longitudinal idistal ridges of the paracone.

The posterior buccal tubercle (2) occupies a smaller area and height in relation to the anterior buccal tubercle (metaconus reduction), they are separated by a pronounced vestibular fissure (7). On its surface, the main longitudinal ridge is clearly visible, which has a pronounced apex, tending to the central fissure. S-shapedly curved medial ridge flows into the central fossa (12), limited from the longitudinal by a pronounced depression.

The distal ridge merges with the distal marginal ridge of the crown and is separated from the longitudinal ridge by a deep groove running into the distal triangular fossa (11). The anterior palatine tubercle (3) occupies the largest area of ​​the masticatory surface; well-defined longitudinal and marginal ridges can be traced on its surface.

The longitudinal ridge has a rounded top, from which a ridge descends towards the central fossa, formed by wide gentle slopes. The slopes are so wide that the recesses that limit them flow into different zones: the medial into the medial groove; distal to the central fossa.

The medial ridge has an S-shaped bend, descends to the medial fissure. The distal ridge has an independent apex, from which the crest of the ridge extends almost parallel to the central fissure and flows into the central fossa.

The posterior palatine tubercle (4) is oval in shape, separated from the others by a distopalatinal groove.

Its surface is practically undifferentiated, although there is a rounded eminence closer to the palatine margin. Rice. 309, 310 show the vestibular surface of the crown of the upper left second molar.

Two odontomers are clearly visible: one of which occupies a large area of ​​the crown and is anterior buccal (1), the other is smaller (posterior buccal - 2).

The odontomeres are separated from each other by a shallow vestibular groove (4) reaching to the middle of the surface. The top of the anterior palatine tubercle is also visible (3). The brown lines show the course of the longitudinal rollers.

There is a narrowing of the crown of the upper molar towards the neck. Rice. 311,312 reflect the coronal part of the palatal surface of the 27th tooth.

Two odontomeres are well defined:

anterior palatine - (1);

posterior palatine - (2), which are separated from each other by a distal palatine groove (3), located in the occlusal third of the crown.

The anterior palatine tubercle occupies most of the palatal surface, its

the outer contour and course of the main morphological elements (brown lines) resembles a module - an odontomer (canine).

The posterior palatine tubercle also has its own structural features: the longitudinal ridge has a medial arcuate bend and ends with a well-traced tubercle. Rice. 313, 314 show the anterior contact surface of the crown of 27.

When reviewing the medial contact surface of the upper second left molar, the presence of two main tubercles (1 - anterior buccal, 2 - anterior palatine) and one additional medial - 3 is determined.

There is a uniform convexity of the vestibular and palatine contours, increasing in the occlusal third of the crown.

The ridges of the main longitudinal ridges along the masticatory slope are clearly visible, converging at a developed angle, where the slope of the anterior buccal tubercle is longer and gentler than the slope of the anterior palatine tubercle. The high medial marginal ridge does not allow a good view of the course of the main fissures.

On the medial surface in the occlusal third, the presence of an additional tubercle, formed by branching of the medial groove, is clearly visible. The place of the greatest convexity and contact with the adjacent tooth is located on the border of the occlusal and middle thirds. The posterior contact surface of the crown of the 27th tooth is shown (Fig. 315, 316).

The presence of two main tubercles is traced (posterior buccal - 1, posterior palatine - 2) and one additional distal - 3.

Similar to the medial contact surface, there is a uniform convexity of the vestibular and palatine contours. The marginal distal ridge is sufficiently pronounced, which limits the view of the masticatory surface of the 27th tooth. The most protruding point is located on the border of the middle and cervical thirds.

It's simple - this is the only organ of the human body that cannot self-repair.

Modern and ancient teeth

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

If you delve into phylogenetics, then the "progenitor" of human teeth is considered fish scales located along the mouth. As the teeth wear, they change - this is a mechanism laid down by nature.

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

The human race is not so lucky, its bite changes only once - dairy ones are replaced by permanent indigenous ones.

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

When our ancestors learned how to make fire, they were able to process food. This made the diet softer and more easily digestible. Therefore, the anatomy of the jaw has again undergone a transformation - it has become smaller. Homo sapiens' jaw no longer protruded forward. She got a modern look.

The teeth of primitive people were not beautiful and did not develop into a radiant smile, but they differed 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 ends by the age of 20 at best.

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

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

By the age of 6, the milk bite begins to change. Besides, molars erupt that had no dairy predecessors.

The process continues until the age of 14. And it ends only when III-and painters erupt - "wise" teeth. They can wait until old age.

Structure

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

1. Crown- visible part.
2. Root- in the deepening of the jaw (alveolus). Attached by a connective tissue of collagen fibers. The apex has a noticeable opening pierced by nerve endings and a vascular network.
3. Neck– merges 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 it 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 the teeth:

Milk teeth have the following features:

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

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

Types of teeth

Teeth differ in appearance and inherent 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 mouths:

• 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 to the optimal size. The upper incisors are distinguished by a wide crown, the lower ones are twice as narrow. They have a single conical root. The surface of the crown with tubercles, which are erased over the years.
• fangs- chewing teeth designed to separate food (only 4 to 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 tubercle, so these teeth look like animal fangs. Canines have the longest root of all teeth.

• Premolars- these are small molars 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 in roots. In the first it is flat forked, in the second it is cone-shaped with a larger buccal surface. The second is larger than the first, the recess in the enamel has the shape of 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 1st tooth is the largest - rectangular in shape with four tubercles and three roots. When the jaw is closed, the molars close and serve as stoppers, therefore they are subject to great changes. They have an enormous burden. "Wisdom teeth" are the last molars in the dentition.

The location of the teeth on the plates is indicated by a special generally accepted scheme. 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 jaws 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. Outside, the cutting edge is slightly beveled.
• Side incisors (2)- chisel-shaped teeth with three tubercles on the cutting surface. The upper third of the rhizome is tilted back.
• Fangs (3)- similar to animal teeth due to pointed edges and a convex crown with only one tubercle.
• I-th root small (4)- a prismatic tooth with convex lingual and buccal surfaces. It has two tubercles of unequal sizes - the buccal is larger, the flattened root of a double shape.
• II-th root small (5)- differs from the I-th by a large area on the side of the cheek and a cone-shaped compressed rhizome.
• 1st molar (6) - a large molar of a rectangular shape. The chewing surface of the crown resembles a rhombus. The tooth has 3 roots.
• 2nd molar (7)- differs from the previous one in smaller size and cubic shape.
• 3rd molar (8)- "wisdom tooth". Doesn't grow for everyone. It differs from the second molar in 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 on the side- more 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 bulge on the side of the tongue. They differ from the upper counterparts in a narrower crown and inward deviation of the root.
• I-th root small- a rounded tooth with a beveled chewing plane. It has two tubercles and a flattened root.
• II-th root small- larger than I, differs in the same tubercles.
• 1st molar- a cubic tooth, has 5 tubercles and 2 rhizomes.
• 2nd molar- identical to I.
• 3rd molar- differs in a variety of tubercles.

Teeth Features

What is the fundamental difference between 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 (side teeth) are needed for chewing food hence the name "chewing". They have a large load, so they have several strong roots (up to 5 pieces) and a large chewing area.

One more trait side elements- high susceptibility. After all, food residues accumulate on their surface, which are difficult to brush with a toothbrush.

In addition, this area is difficult to see with a normal eye, 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 "sickest" tooth is a wisdom tooth. It's a shame that it is not useful, its functions have long sunk into oblivion. And lucky those who have it remains in its infancy and does not seek to grow.

The anatomical structure of the third molar does not differ from other teeth. It just has a shortened trunk and a few tubercles.

In total, a person should have four "wise" teeth- 2 on each arc.

But “wise” teeth erupt later than the 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 appear half(semi-impacted teeth) or not erupted (impacted teeth). The reason for such harmfulness is in 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 lost their functionality. Scientists still don't have an answer as to why they keep growing.

Pain during the eruption of the third molar is felt due to its overcoming the mechanical impact, because the jaw is 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 rests on the tongue or cheek, avoid inflammation and injury.

Another unpleasant diagnosis is pericoronitis. A "wise" tooth can climb for years, because of this, the mucous membrane suffers.

Chronic inflammation occurs, the gum becomes dense.

As a result, there appears slimy hood, which provokes purulent processes. Only a dentist can solve this problem with surgery.

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

If the wisdom tooth is very painful, then it is better to remove it, don't bother with this. Over the years, it settles more and more densely in the gum, which, when removed, can provoke some problems.

Curious facts

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

• Twins and twins also duplicate the dental "composition". If one is missing a specific tooth, then the other is missing it.
• The right-hander often works with the right side of the jaw, the left-hander - respectively.
• Jaws designed for huge load. The maximum chewing muscle strength approaches 390 kg. Not every tooth can do it. If you gnaw nuts, then you create a pressure of 100 kg.
• Elephants change their teeth 6 times. Science knows the case when a 100-year-old man's teeth were replaced for the second time.
• Enamel on teeth is considered the hardest fabric 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.
• most expensive tooth belongs to the scientist Newton, it was sold in the 19th century for 3.3 thousand dollars. A buyer of aristocratic origin adorned a ring with it.

• Legend has it that Buddha had 40 teeth and Adam had 30.
• Neanderthals didn't have cavities because of healthy food.
• Some babies are born with a prenatal tooth in the lower jaw (1 in 2,000 cases).
• Each dentition is unique like fingerprints.

By mistake, we do not consider teeth to be an important organ. But it is a complex and fragile system. Each tooth has its own characteristic structure and performs a specific function.

A change of bite in a person occurs 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 they are to clean and easier to care for.

Molar teeth are present in children and adults, but their number differs. For example, babies have 8 of them, and teenagers, women and men have from 8 to 12. The number of these teeth in the oral cavity depends on how many "eights" have erupted in a person. The molar, which grew from above, has three roots, while the lower ones have only two. The number of channels is also different, there can be several channels in one root. They are characterized by an impenetrable and twisted character.

These teeth have a large crown, in shape they (in the upper part of the jaw) look like a rhombus, and from below they look like a cube. The chewing surface is characterized by the presence of several tubercles - from 4 to 6, which can be of the following types:

• buccal - located closer to the cheek;
• lingual - closer to the language;
• distal - distant tubercles;
• mesial - near.

The tubercles on the tooth surface are separated by special grooves. "Eights" do not necessarily erupt on time: they can remain inside the jaw, i.e. be replayed. In a child, they erupt at different times, but by the age of 2.5 almost all of them appear. The cutting schedule looks like this:

1. At 1 year old, the baby's first two molars erupt - one at the top and one at the bottom.
2. At 1.1–1.2 years, the first ones appear. They are located on the lower jaw.
3. At 1.8 years, the lower ones appear.
4. At 2 or 2.5 years, another pair of upper ones erupts.

Simultaneously with this, milk teeth grow, and if they erupted completely, then it is time for the growth of the next pair of molars. This usually happens at 6 or 7 years of age. First of all, the "six" appears on the lower jaw, and the second - a little later on the upper. At age 12 or later, "sevens" begin to appear. The molars also include wisdom teeth - "eights", which begin to grow from the age of 17, but are able to erupt in each person in different ways. The appearance of wisdom teeth is individual. The molars are located behind the premolars. Usually adults have three pairs of molars - “sixes”, “sevens” and “eights”.

The maxillary molars are the largest, with an average length of 22 mm, with a minimum length of 20 mm. The buccal tubercle, which is located in front, depends on the fissure - a groove running from the anterior surface, smoothly turning into the buccal. Further, the groove stretches to the very neck of the tooth.

On the back wall of the tooth, the tubercle is characterized by a groove that stretches along the masticatory area, and then passes into the lingual. The tubercles, which are located in front and behind, are separated from each other by a strip that runs exactly along the center of the chewing surface. This is the central fissure connecting the other two grooves.

The tubercles differ in shape: they are rounded near the tongue, and conical near the cheek. Interestingly, the anterior tubercles are much larger than the posterior ones. They are sometimes accompanied by an additional, so-called anomalous tubercle. It got its name due to the fact that it does not reach normal sizes and does not take part in chewing.

Other features worth noting include the following. Near the cheek, the surface is distinguished by a convexity and the fact that it is divided by a groove. The curvature of the enamel is strongly pronounced. On the lingual surface, the groove is smaller and gradually passes into the masticatory area. The back of the molar is more convex than the front, but smaller in size than the surface that is in front.

On the upper jaw, they have three roots that have different shapes. The first of them is called palatine and looks like a cone, and the other two are buccal, one is larger and the other is smaller. The roots are compressed on both sides. The root of the anterior molar has a well-defined structure.

The second molar, which is located between the teeth of the upper jaw, is somewhat smaller than the first and has an average size of 21 mm. In general, its dimensions can be from 19 to 23 mm. The crown has its own specifics, which is worth considering in more detail, since it can occur in people in three different variations.

Firstly, it looks like the crown of the first molar, but there is no abnormal tubercle. And he never shows up. Secondly, three tubercles grow on the chewing surface, which are located in the anterior direction. They are formed by combining the anterior lingual tubercle with the posterior one. Thirdly, the crown has a rhombic shape and is strongly elongated in the anterior direction. On the surface there are three tubercles, which are arranged in the form of a triangle. One of the peaks is palatal, and the other two are buccal. The most common among people are the first and third types.

In the second molar, the curvature of the crown is clearly visible, it has three roots. Those of the roots that are located near the cheek are able to merge into one. Some people have situations where all the roots merge into one and have the shape of a cone. In places where they have grown together, grooves may appear. The root is perfectly traced and expressed. The second molar can have 3 canals - in half of the cases, 4 - are typical for 40% of people. Very rarely there are two channels or one.

The third root, which is a molar and is located on the upper jaw, has its own characteristics:

1. Irregular shape and size.
2. A wisdom tooth can be shaped like an awl.
3. On the surface that takes part in the chewing process, there are 3 tubercles. But there may be teeth where 4, and even less often 5 or 6 tubercles will grow.
4. The roots have different shapes and sizes, depending on the characteristics of the jaw of each person and genetic predisposition. There can be from 1 to 4-5 roots, although in medical practice there are teeth with 8 roots.

What are the characteristics of mandibular molars? At the bottom of the jaw are also such teeth. The first, the root, is large in size, which ranges from 20 to 24 mm with an average length of 22 mm. On their surface there can be 5 tubercles, which differ from each other: 2 - belong to the lingual, 3 - are located near the cheek.

Between the tubercles there is a longitudinal strip - a fissure, which runs clearly along the edge of the chewing surface. There is also a transverse groove running from the cheek to the lingual, and at the same time crossing the masticatory area.

The tubercle, which is the third and is located near the cheek, is created by a small groove extending from the transverse one. The buccal surface of the third tooth is curved, and the lingual surface is rather convex. There is also a difference in the structure of the rear and front surfaces. The first has a greater bulge than the front, which is much larger than the back. The crown is able to deviate to the lingual surface. The number of roots is two, and they are divided into anterior and posterior, which are compressed on one side and the other. Roots are strongly expressed. The first molar usually has 3 canals, rarely 4, and quite rarely 2 canals.

The second molar tooth at the bottom of the jaw is different from the first. There are only 4 tubercles on the chewing surface, which are divided into buccal and lingual. They are separated from each other by one transverse and one longitudinal grooves. Sometimes there may be a fifth, anomalous tubercle.

The crown resembles the structure of the first molar of the lower jaw. The number of roots is the same, dividing into anterior and posterior, having a somewhat flattened shape. The roots are pronounced, and 3 canals pass through them - one posterior and two anterior. Some people have four channels. In all cases, the roots have the ability to merge.

Third, the lower wisdom teeth are large or somewhat smaller, may have a different shape. The crown is covered with 4 or 5 cusps, although lower third molars also have 6–7 cusps. There are tubercles posterior and anterior, which are larger and higher than the first. These teeth have 2 roots, and they often merge into one conical one.