Human teeth - structure, quantity, numbering and composition

Teeth of ancient people

The dentofacial apparatus of prehistoric and modern humans differs significantly. Ancient people had more than 36 teeth, protruding fangs and a massive jaw. This was explained by the need to chew rough food and raw meat. With the addition of thermally processed foods to the diet, the dentition began to change. The canines were the first to transform, becoming aligned with the bite line. Then the jaw arch narrowed, the interdental spaces disappeared, and the teeth themselves decreased in size. Currently, 32 teeth in humans are the norm, but third molars are considered to be an atavism.

Interesting fact!

The teeth of ancient man cannot be called aesthetic, but they were healthy. According to scientists, cavemen never suffered from caries and other oral diseases.

Panoramic dental x-ray

If pulpitis or another disease is suspected, the dentist sends the patient to take a photo of the diseased tooth. But sometimes it is difficult to determine exactly which tooth is the source of the problem. If the gums are inflamed, a person simply cannot understand where exactly it hurts.

Previously, in such cases it was necessary to take x-rays of nearby teeth. Today, the doctor will definitely refer you for an orthopantomogram - a panoramic image. This method allows you to get a “picture” of the entire oral cavity at one time. Moreover, from such an image it is possible to determine not only caries or periodontal destruction. A panoramic x-ray of the teeth will reflect the condition of the alveoli, sinuses and even maxillofacial bones.

Experts also advise periodically taking panoramic dental x-rays for prevention. This diagnostic method will allow you to identify inflammatory processes at the tops of the roots of the teeth even before toothache begins to torment you. And having seen the general picture of the state of your dental system, the dentist will prescribe a targeted photo of the questionable tooth in case of any deviation.

After the therapy, especially if it took place in several stages, you may need to repeat dental x-rays. This will allow you to notice and eliminate defects in the canal filling in a timely manner.

If, according to indications, you are offered to remove a wisdom tooth, a panoramic photograph will also be useful. The surgeon needs to see the entire area around the problem area - the area of ​​the upcoming operation.

If you decide to have prosthetics, install braces or implant an implant, be sure to take a panoramic photo. Such an X-ray of the teeth in this case will allow the doctor to fully assess the condition of your oral cavity and decide on a treatment regimen.

So, if you are determined to correct your bite, the orthodontist will ask you to do an orthopantomogram in order to use it to analyze at what angle the roots of the teeth are, and whether there are teeth that are not visible, but they are located inside the jaw bone - the so-called impacted teeth. This information will allow you to perform bite correction as successfully as possible.

If you are going to have dental prosthetics, it is necessary to exclude hidden problems - a dental cyst, granuloma or tumor. The size and boundaries of these neoplasms are quite clearly visible on a panoramic photograph of the teeth. With a traditional x-ray, when only 1-2 teeth are reflected in the image, the doctor risks missing the threat.

When placing an implant in the upper jaw, the implantologist will use this image to estimate the distance to the maxillary sinuses. This is necessary so that during the procedure the implant does not enter the maxillary sinus. If you need to place an implant in the lower jaw, it is important to make sure that it does not touch the nerve.

How is a panoramic dental x-ray performed?

Everything is elementary simple: you just need to stand at a special installation for a few seconds. And within a couple of minutes the photo is in your hands. Before starting the procedure, be sure to remove all metal objects from yourself. They interfere with the passage of the X-ray beam, which means they can cause image distortion. The most modern devices are digital, they allow you to store your pictures in the computer's memory. After all, they can be useful to you at an appointment with a variety of doctors - dental therapists, maxillofacial surgeons, orthodontists, implantologists, and so on.

Another plus is the price. A panoramic dental x-ray will cost you much less than taking pictures of several problem areas. In addition, modern technologies make this procedure as safe as possible, even for young patients. After all, the radiation dose is reduced to a minimum. But do not forget that for some chronic diseases, as well as during pregnancy, any x-ray is contraindicated. Therefore, before the procedure, be sure to discuss all the nuances with your doctor.

Name of human teeth

Depending on the location and structure, dental units have their own functional characteristics and are called differently.

• Incisors.
  On both jaws there are four front teeth in humans - medial and lateral incisors, which are used for biting food.
• Fangs.
  Sharp teeth designed for chewing hard foods.
• Premolars.
  "Fours" and "fives" on the left and right sides of each jaw arch grind soft or small pieces of food.
• Molars.
  Three large outer teeth in each row are aimed at grinding coarse substances.
• The canines
  and incisors are part of the anterior group, or the “smile zone,” and the human molars are part of the chewing segment.

In addition, teeth are divided into temporary and permanent. In the first case, we are talking about dairy products that appear in children from the fifth month of life to three years. The second refers to the final bite, which is formed between six and thirteen years of age. Milk teeth differ from permanent teeth only in size, but in structure they are identical.

Photos of dental implantation before and after

Photo of dental implantation on a beam

All on 4 implantation photo

All on four implantation photo

Installation of 4 implants of the Superline Dentium system using All on 4 technology and installation of a fixed denture. Orthopedist Shagin L.V., surgeon-implantologist Kurbatov V.O.

All on Four implantation photo

Photo of one-stage dental implantation

Tooth extraction and photo of one-stage implantation

Simultaneous removal and implantation in the area of ​​25 and 26 teeth. Without bone grafting, but using a centrifuge.

How many teeth does a person have?

The number of teeth a person has depends on age and anatomical features. The child has a set of 20 primary teeth, which are replaced by a permanent bite of 28 teeth. Third molars erupt, as a rule, after twenty years or do not grow at all, which is not a pathology.

In dentistry, a single numbering of human teeth is adopted. Doctors classify teeth as lower and upper and distinguish the right and left segments of the jaws. Each of them includes two incisors, a canine, two premolars and three molars. The countdown starts from the first front tooth and ends, accordingly, with a figure eight. Sometimes a number is added to the serial number indicating the location zone. For example, the right canine of the top row is numbered 13. This order in the schematic representation is called the formula of human teeth.

Polyodontia

In rare cases, an anomaly such as polyodontia is observed - supernumerary, or extra teeth in a person. Dental units can appear in the primary and permanent dentition anywhere in the jaw, separate from or fused with the main teeth. The defect affects not only the aesthetics of the smile, but also leads to the formation of incorrect occlusion, impairs the quality of chewing food and diction. Most often, supernumerary teeth are removed in childhood or built into the dentition.

Edentia

There is also a deviation of the opposite meaning called edentia - congenital or acquired absence of dental units. The causes of the phenomenon include heredity or improper development of the embryo in the womb. People without teeth cannot fully eat and speak, have a deformed facial contour and weakened immunity.

Causes of tooth enamel destruction

There are a number of factors that exacerbate the rate of enamel damage. These include:

• the anatomical structure of the tooth, when a large amount of food accumulates in the dental cavities and spaces between the teeth;
• insufficient saturation of enamel with fluoride;
• genetic predisposition;
• weak immunity, various diseases of the body;
• composition of salivary fluid - a small amount of saliva, viscous in composition, causes the accumulation of bacteria on the surface of the tooth and in the dental spaces, and consequently, the formation of dental plaque;
• insufficient oral hygiene, improper brushing of teeth;
• eating mostly soft food (soft food weakens the protective functions of enamel, while hard food helps to naturally strengthen teeth);
• lack of vitamins and beneficial microelements in the human body;
• The bristles of a toothbrush used for oral hygiene are too hard.

Restoration of tooth enamel is required for those who eat large amounts of citrus fruits (oranges, lemons, grapefruits), which significantly weaken tooth enamel. The acid contained in these fruits tends to dissolve the protective surface of the tooth. Therefore, after eating citrus fruits, be sure to rinse your mouth with water.

Dimensions of human teeth

The upper central incisors are twice as wide as their antagonists. The remaining dental units of the same name have approximately equal parameters. The size is determined using special tables with the optimal size and permissible deviations. Experienced doctors calculate proportions by dividing the length of a person’s teeth by the width. A result of about 0.75 millimeters is considered close to ideal. For more detailed diagnostics, other professional formulas and techniques are used.

Size deviations from the norm occur due to improper formation of the jaw, fusion of tooth buds, or genetic predisposition. Teeth that are too large are called macrodentia, and abnormally small teeth are called microdentia. Pathologies are accompanied by problems with bite and chewing functions, but can be successfully corrected by a dentist.

Interesting fact!

The longest tooth in the world belongs to an Indian teenager. The size of its crown is almost four centimeters. About a year ago, the tooth was removed, and the young man was included in the Guinness Book of Records.

Photos of dental treatment before and after

Photos of dental restoration

Photos of treatment of superficial and medium caries

Photos of dental caries treatment

Photo of pulpitis treatment

Photos of deep caries treatment before and after

Restoration of wedge-shaped defects

Dentist: Kharlamova Ekaterina Andreevna

Treatment of dentin caries

Dentist: Kharlamova Ekaterina Andreevna

The structure of the human tooth

Anatomy

From an anatomical point of view, a human tooth consists of three parts.

• Crown.
  The visible part protruding above the gum. It has four sides: the occlusal, or cutting edge, in contact with the antagonist teeth; contact wall adjacent to adjacent dental units; vestibular and lingual surfaces facing the lips and tongue, respectively.
• Root.
  Fixed in the socket by connective tissue, located in the recess of the jaw. As a rule, premolars have two roots, and molars have three, four or even five. The remaining dental units have one root canal.
• Neck.
  It is located between the coronal part and the root of a human tooth, surrounded by periodontium.

Histology

What are human teeth made of? Let's look at the cross-section of the structure of a human tooth.

• Enamel.
  A transparent protective coating of the crown, almost entirely consisting of inorganic microelements.
• Dentine.
  The hard base of the tooth, containing 80% mineral components and 20% organic substances. The shade of dentin is responsible for the color of dental units, as it shines through the enamel.
• Cement.
  The bone tissue covering the tooth root. Plays the role of a fastening element connecting the tooth to the alveolus.
• Pulp.
  Soft tissue filled with bundles of nerves and capillaries. Painful sensations during caries are explained precisely by the presence of nerve endings.

Myths about tooth enamel

Here are some common myths and misconceptions about tooth enamel.

The first myth is that enamel is destroyed very quickly. Actually this is not true. The process of enamel destruction is gradual and can last ten years. This is why proper prevention of tooth enamel destruction is so important.

The second myth is that tooth enamel is destroyed immediately on most of the teeth. This is also not true. It happens that one or more teeth suffer from enamel destruction more than the rest. This is a sign that inflammatory processes have begun inside the tooth and it is necessary to urgently contact a dental clinic.

The third myth is that enamel destruction is not a disease. In fact, damaged enamel is not only a cosmetic defect, as many people think. This is a disease, the progression of which can lead to complete destruction of all tooth tissues and subsequent loss.

The fourth myth is that enamel destruction can be diagnosed only by external signs (darkening of the tooth surface, the formation of pigment spots). This is not true. Symptoms such as an acute reaction of teeth to external irritants (cold, hot and cold food), as well as the presence of toothache (cutting or aching), indicate that your tooth enamel has been destroyed.

Human wisdom teeth

A “wisdom tooth” is the third outer molar with three to five roots. In structure it is no different from its “neighbors”. To the question “How many wisdom teeth does a person have?” cannot be answered unambiguously. They erupt around the age of twenty, one on each side of both jaws. However, there are people without wisdom teeth. This is a variant of the norm, since in the process of human evolution the need for the “eight” disappeared, and the structure of the jaws underwent corresponding changes. Today, third molars are considered a vestigial organ.

Why is tooth enamel destroyed?

The destruction of tooth enamel may be a natural consequence of the patient’s age. People in the age group of fifty years and older very often complain of a decrease in the protective functions of enamel. This is a consequence of age-related changes in the body.

Enamel destruction can also be observed in pregnant women. In this case, this is a consequence of hormonal changes occurring in a woman’s body.

There are also slightly curious reasons for the destruction of the tooth surface. For example, when a person tries to crack a too-hard nut with his teeth (special tools are available for this) or demonstrate to friends how he can open glass bottles with his teeth. Such events are very dangerous because they can result not only in the destruction of the enamel, but also in the fact that the tooth can break or chip off.

How does the procedure work?

Panoramic photography of teeth is the specialty of a dental radiologist. It is carried out using an orthopantomograph - a modern device that exposes the body to a minimal amount of x-ray radiation.

To take a photo, you need to stand or sit near the device. Next, the patient must wear a protective apron that protects the chest from radiation. When the patient is ready, the doctor starts the orthopantomograph. The entire procedure lasts no more than 15 minutes and is completely painless.

During the process you must remain stationary. After the panoramic photo is taken, you need to wait a few more minutes. During this time, the specialist will prepare the image and provide it to the patient. The entire procedure lasts no more than 15 minutes, including the time required for preparation and waiting.

How to straighten crooked teeth?

The selection of a means for straightening crooked teeth is carried out according to the type of anomaly and taking into account the patient’s age.

To correct malocclusion in children, removable plates or trainers are used. They perform several functions:

• align the position of teeth and jaws;
• normalize muscle function;
• relieve excess pressure from the jaws that the tongue and cheeks exert during conversation or eating.

The use of removable corrective devices is effective only up to 10-12 years. After this, the child develops a permanent bite, which can only be corrected with special mouth guards or braces.

Modern dentistry provides a huge selection of braces. Most often they are installed on the outer surface of the teeth. Unfortunately, they are noticeable during conversation and spoil the aesthetic appearance of a smile. If the aesthetic factor plays a key role, you can install special lingual braces. They are placed on the inside, so the adjustment occurs almost unnoticed by others.

What causes malocclusion to form?

Defects appear for various reasons:

1. Genetic predisposition. In most cases, mesial and distal bites are inherited. Therefore, parents who have this problem should take their child to an orthodontist in early childhood.
2. Anomalies of fetal development. A child’s teeth are formed while still in the womb. During a complicated pregnancy or the influence of negative factors on its course, anomalies of the dental system can form.
3. Birth injury. Mesial bite in some cases is a consequence of dislocation of the baby’s lower jaw during childbirth.
4. Bad habits. Constant thumb or pacifier sucking, improper latching of the nipple, incorrect sucking during artificial feeding - all this provokes the development of malocclusion pathologies.
5. Inferiority of the dentition. You can resort to removing baby teeth if there is less than a year left before the change. Otherwise, the dentition becomes asymmetrical, the midline shifts, and the chewing movements of the jaw are blocked. The formation of a permanent bite ends at approximately 15 years of age. For adults, after tooth loss, it is important to undergo prosthetics in a timely manner.
6. Displacement of the jaws as a result of hypertonicity of the masticatory muscles, which can be observed due to stress.

Jaw injuries, as well as improper prosthetics, can provoke the development of malocclusions.

Correct bite: what is it like?

Bite is the way the teeth of both jaws interact when they are completely closed. If it is correct, there are no difficulties when chewing and pronouncing sounds, the aesthetics of the smile is not impaired, but minor defects are still possible. What does a bite that does not require orthodontic treatment look like? Its main characteristics:

1. Presence of 28–32 teeth. Not all people develop “eights”, which is determined by genetic factors. Their presence (if they have grown correctly) or absence does not affect the closure of the jaws. Moreover, in some cases, wisdom teeth removal is indicated during orthodontic treatment. Then there is more free space in the mouth.
2. Symmetry in the closure of the dentition.
3. The incisors of the upper jaw overlap the lower ones by one third.
4. No interdental gaps, cracks or chips.
5. Correspondence of molars and premolars of both dentitions to each other. Their closure is tight.
6. Ease of chewing food, even hard ones. Opening the mouth is easy and there is no pain.

Correct bite does not always look aesthetically ideal. But the face is harmonious.

Photos of veneer installation before and after

The color and shape of teeth are changed by veneers. The total cost of installing veneers was RUB 320,000. Orthopedic doctor Yuri Anatolyevich Lychko

Photo of veneer installation

Photo of installing veneers on front teeth

The shape and color of teeth are changed through the use of veneers. The cost of installing veneers is RUB 370,000. Orthopedic doctor Yuri Anatolyevich Lychko

Photo of installation of veneers on the upper jaw

The shape and color of teeth are changed using veneers. The cost of installing veneers is 180,000 rubles. Orthopedic doctor Yuri Anatolyevich Lychko

Photo of veneer installation on one tooth

Trauma to the central incisor. The tooth was restored with a veneer. Installation price - 34,000 rubles. Orthopedic doctor Yuri Anatolyevich Lychko

Installation of a metal-ceramic crown

Installation of a mandibular bridge on the right

Photo of installation of a zirconium dioxide crown

Photos of a zirconium crown before and after

Installation of a zirconium crown on a Nobele Biocare implant, screw fixation. Orthopedic doctor Leonid Vladimirovich Shagin.

Photo of installing a zirconium crown on an implant

Zirconium crown on the implant, installed using screw fixation. Orthopedic doctor Leonid Vladimirovich Shagin.