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Case-lesson «Tooth hurts»
Case-lesson «Tooth hurts»

Category: Personal growth

The level (grade): 7+

Subject: Lessons of health, safety and medicine

Objective: To learn about the integrated vision of the human body; to acquire the ability to "hear" the needs and problems of the body and proper reactions to them

What information is waiting for me here?

  • Who has the most powerful jaws?
  • How to determine the bite force.
  • Who has the biggest teeth in the world?
  • Why do teeth need calcium?
  • Why do tooth start to decay? What can you do to prevent this?
  • Is it possible to grow new teeth?
6 scans of the subjects, phenomena and practices:

Unfortunately, our culture does not produce a habit to monitor the health of teeth. You can say that we are not monitoring the whole organism. Moreover, how to do it, if the body has many systems and even more working bodies?

In fact, the brain controls all systems and organs of the human body. For example, if the brain stops to control the dozens of muscles for one second when a person stands, the person will fall down. Therefore, the brain has enough work that we do not notice.


When you have toothache – it is a brain gives a signal about a malfunction in the body. However, the brain is unable to report what happened exactly. Most likely, there are problems with food or nutrients absorption.

If we have a habit to monitor the condition of the body before the pain starts, we will get rid of trouble in a month, a year, and ten years. For example, a useful habit is inspection of mouth with dental mirror. It will give the opportunity to notice violation as early as possible and quickly eliminate it.

What is the compression force of the jaws of a man?

If all the muscles of the jaws reduce simultaneously, the compression force of the teeth can reach up to 25 kg for cutters or 90.7 kg for molars. The maximum compressive strength is 122 kg.

What jaw are the most powerful?

How to determine the bite force?

There is the generic formula for the pressure:


That is, to answer the question, it is sufficient to calculate the total area of the acting surfaces of the teeth and determine the pressure force. However, a special device usually measures the pressure – dynamometer:


The main thing is to make the object of the experiment to bite the dynamometer.

Knowledge of this simple formula has allowed scientists to answer many unusual questions. For example, what was the bite force of an ancient piranha – ancestor of modern toothed predatory fish? After all, even modern piranha boasts an extremely powerful jaw. Scientists created a model of the jaw in bronze. Experiments gave the opportunity to evaluate the depth of penetration of the teeth:


In addition, given the bite force and the muscle mass involved, we can calculate the power ratio of the bite force quotient. It is calculated as the ratio of the force bite to the mass of the involved muscles. For example, "rating" for predatory fish is:


Human jaws are also quite powerful and it will be enough pressure to chew nuts (hazelnut). Moreover, it is possible to move loads with the jaws!

However, we should warn of such experiments. We should even to eat seeds not so much, because teeth will wear out faster than grow.

Nevertheless, if the squirrel will not chew on nuts, its teeth will grow so that it will not be able to close the mouth.

The teeth are "working" due to the pressure. However, the pressure applied can affect teeth locally! Brackets are based on this action.

The source http://www.ardenta.ru/ortodont4.htm describes these processes like that. For teeth straightening, we need to get them moving, which they get being under pressure that makes certain loads. This is necessary in order to make the bony part of the tooth started to change: to grow in one place and decreased in another. Such bone becomes more mobile and the pressure on it can be increased. Orthodontists "rigged" brackets at this stage.

The teeth of adult are corrected with brackets, but the plate can cope with teeth of a child. The difference is in the force of action, duration and permanence, because the braces are worn the course of a year or more without removing.


However, the trainer or the plate can be removed! The plates can have quite interesting colors and designs:


If customer can choose color, the orthodontist can choose the right form.

Brackets "work" on each tooth in all three directions. Plates do not have such properties. Therefore, if the tooth needs to expand or skew, brackets must be used.


The tooth is moved from the outside. Brackets are attached on the external surface. It is fastened with a rubber band to pull the tooth closer to the arc. When the tooth has shifted, the brackets are interconnected. The teeth need to shift forward a little. Its bracket is connected to the arc, trying to regain its original position. Due to this, the tooth moves in the desired direction. The tooth falls out of the dentition, there are the gaps between the teeth. The bracket transmits the load from arc to the tooth, and it is in the right position. The arc pressure is strong enough; it almost pushes the tooth in the right place. If the tooth needs to move down, the bracket is mounted higher than other teeth. The arc tries to straighten up, tightening the tooth.


A skilled doctor is able to affect not only the teeth but also the jaw as a whole. If one jaw is lagging behind in growth from other, brackets or plate can be configured in such a way to push almost all the teeth.

If the jaw is increased, the pressure on the teeth is done from the outer side of the dentition. When it decreases – vice versa.


According to research, the ancient dinosaur Tyrannosaurus had the bite force about 50.000 N. What pressure had he acted on the surface of 30 sq cm when biting?


What was the ratio if the mass of the t-Rex was 5 tons (take the "average" instance)? It used 15% of mass for biting.


What is the tooth? What does it consist of and what are the types of human teeth? The visible part of the tooth called a crown, covered with enamel – the hardest substance of the body; it is relatively resistant to destruction.

The neck of the tooth is immersed in the gum, and the root is in the jawbone. Dentine is underneath the enamel. It forms the bulk of the tooth. Dentine is quite strong, although the enamel is hardness and more resistance to damage. It is penetrated by numerous tubules contain cells that form dentine.

In the end, the cement in bags is much cheaper than cement teeth at the dentist. Numerous fibers that are attached at one end to the cement and the bone firmly hold the tooth in place. However, the tooth has some mobility, thereby reducing the likelihood that the tooth will break when chewing


It is well known that the teeth begin to erupt in the age of 6 months. Although there are deviations from this "constants". There is a special formula, which allows calculating the number of teeth that must be the child's normal. Note that it is relevant only for primary teeth!


Change of teeth starts in the age of about 5 years and ends in the age of 15. Up to 5 years, the interdental space becomes wider. It is preparation of the jaw to the process of change.


Permanent teeth are between the roots of primary teeth, so the process of changing begins with resorption of root from the side that is adjacent to the embryo. The process develops from the apex and gradually reaches the base. At this time, the tooth begins to stagger, and when the neck is affected, and then it falls.

The process occurs in two directions simultaneously: the first teeth fall, permanent – grow. An important factor in this period is the fact that will fall at first.

The first teeth will fall in the same order in which they grew. The scheme is always the same: first, incisors are changed, then – premolars, and the canines.

Is it difficult to diagnose the tooth decay? For example, sometimes black dots and spots on the teeth are visible. However, of course, it is not always. The infection may develop unnoticed in the gaps between the teeth, for example.


Despite the fact that today dental caries is the most common dental disease, the causes of its formation are uncertain.

According to modern views, there are a number of local and general factors that contribute to caries formation. Local factors are microorganisms and the quantity and quality of saliva.

According to this theory, enzymatic digestion of carbohydrates by microorganisms forms a number of acids, particularly lactic, which lead to enamel demineralization and the subsequent invasion of microorganisms into the tissues of the tooth.

On the other hand, it was observed that reduced flow of saliva violated the protein and mineral metabolism in teeth, which also contributes to tooth decay.

In addition, there are hereditary factors, oral hygiene and excessive consumption of sweets. When you eat sweets, the value is not important but the duration of collision with the surface of the teeth. In addition, the quantity consumed of calcium, phosphorus and fluoride in the diet are important.

What is a toothache? The nerve in the tooth or the gums sends pain signals. The pain cannot be ignored, as a pathological process will develop.


That is, the nervous signal is transmitted by neurons and perceived by the brain as pain:


In addition, who has more teeth? It is clear that man, even with all the wisdom teeth is not the record. Then who?


The teeth of sharks and snails are constantly updated!

However, the most bloodthirsty predators have fewer teeth than the harmless snails. The cat and all felines (lions, tigers) number of teeth in the mouth are only 30. Moreover, dogs, wolves and foxes have 42 teeth.

Rabbit and squirrel have 28 teeth 22 teeth.


Ask your mother about your first teeth and compare with the schedule.


Teeth need calcium. It has become an axiom. However, why, and in what quantity?

Although teeth and bones need calcium but it is also part of the blood and other organs. What is the role of it? Calcium participates in the formation of our bones and teeth, regulates the growth and activity of all cells, improves metabolic processes, and normalizes the nervous system. In addition, it normalizes blood clotting, removes inflammation, and strengthens the immune system. Therefore, every adult should get 05-1 g of calcium.


In the body, the calcium is most often in the form of an ion. It takes part in membrane processes. What reaction is able calcium as a chemical element?

Its atoms on the outer energy level have two electrons. It easily loses electrons and becomes positively charged ions CA (2+). In all compounds, calcium is only covalently. Calcium belongs to the most active metals. According to the chemical activity, it is the second after the alkali metals.

At ordinary temperatures, calcium easily reacts with oxygen and moisture of air:



Calcium can also interact with acid quite actively. Therefore, too acidic environment in the mouth is dangerous! In ionic form, the process will be:


The crystals of various apatites are mineral base tissues. The core is hydroxyapatite Ca10(PO4)6(OH)2 and 8-calcium phosphate Ca8H2(PO4)6 • 5H2O. Others are given in the table:


Sometimes doctors, including dentists, prescribe to take pills with calcium. In this case, do not forget about taking vitamin D, which helps calcium to be absorbed in the body and to stay there longer.

Which foods contain calcium? There are whey, yogurt, cottage, cheese. In addition, there are parsley, almonds, and cabbage and sesame seeds.

It should be remembered that organic calcium after heat treatment is converted into inorganic. Inorganic calcium is poorly absorbed in the body.

How is dangerous a lack of calcium in the human body? Frequent cramps of the limbs can happen. Also it affects the condition of the teeth. This means that you have to go to the dentist. In addition, the lack of it affects the condition of the bones. Osteoporoses can develop – it is when bones become very fragile.

Why is it said, "Teeth are rotting"? Is it happening only because the tooth "impoverished" in calcium? No, the process is much more complicated, it is not purely chemical, but is more of a biochemical nature. It is based on a process that involves cleavage of the protein molecule of the tooth structure. This is a gradual process, and therefore the depth of the destruction of the tooth may be different, depending on which part of the fabric was destroyed. The main "culprits" – the bacteria, especially Bact. proteus vulgare:


Processes are according to this scheme:


The final stage activates at low pH, i.e. in an acidic environment!

Processes of demineralization are associated with calcium. It triggers tooth decay. The process of enamel demineralization is accompanied by a change of shape, size and spatial organization of hydroxyapatite crystals.

Up to a certain point the loss of CA (2+) is not accompanied by destruction of the crystal lattice of hydroxyapatite. Nevertheless, in the future, along with CA (2+), phosphates are lost and crystalline are collapsed. The contents of calcium, phosphorus, fluorine and other elements are reduced in the areas of destruction.

Saliva is the secret of the salivary glands and an important biological environment of the oral cavity. Therefore, its properties and chemical composition significantly affect the condition of the teeth and the mucous membranes of the mouth.


Make a diagram of the reaction for CA and hydrochloric acid, which contained in the saliva in very low concentrations, but has effect on homeostasis (balance) of environment of the oral cavity.

Find out the list of foods that can lower and raise the pH. Make a list of such products. How often do you eat them?


Is it possible to treat a tooth without a drill? Japanese scientists said "YES"! They invented the toothpaste that can be used to restore the enamel safely and quickly.

The new paste consists of material like enamel. The toothpaste can be applied directly on a crack in the tooth. A unique material was received because of experiments with the main component of teeth – hydroxyapatite.

Acid contained in the paste, dissolves the enamel that cracked. After three minutes, the substance crystallizes, and the material is embedded in the tooth structure. In doing so, the paste gives excellent antibacterial effect.

Tests showed that the cured tooth is not different from the healthy, and the difference cannot be seen even under a microscope. However, it is worth noting that not all problems can be solved using toothpaste.

Is it possible to grow a new teeth instead of lost? The research group of Professor Paul Sharpe from king's College of London has developed an innovative technology for growing teeth using stem cells of patients.

Stem cells were grown in the lab, taking the form of the tooth. They were put in the gums of the laboratory mouse. After a few months, a healthy tooth grew on this place.

The next step will be to test new technologies on people. The professor is sure in success. As scientist noted, the new method of growing teeth helps to abandon artificial jaws and complex operations to implant metal pins.


Is it possible to grow a new tooth in mouth? Professor of dentistry of Columbia University of United States of America Jeremy Mao has conducted a number of experiments on animals. The results confirmed that the teeth could be grown directly in the mouth.

The technology of implementation of this method is as follows. The collagen skeleton of the new tooth needs to be placed in the area of the lost. This frame is applied with a special growth factor beta-3. A special protein controls the growth and differentiation of cells.


This material was made from natural porous substances, which have the ability to grow. Thus, stem cells will simply grow into this frame, and as a consequence – completely new tooth. Besides, it is worth noting that according to its characteristics, the new tooth in no way differs from the old natural tooth.

The professor said that the new tooth grows for nine weeks and has the ability to regenerate.

Recently, it has become clear that one of the most popular and profitable professions of our time just disappears. It is more efficient to make teeth with 3D printers. Using special programs, teeth are not only made with nano-precision, but also implanted into their space delicately.


How do you brush your teeth? This is one of the first questions asked by dentists. How do you do that? Let us compare your answer with the option, which the doctors propose.

The correct method of teeth brushing requires at least two minutes! Do not be lazy; you can even begin to fix the time.

What brush should be chosen? How often should you change it? The majority of dentists believe that brush with soft bristles is the most suitable for removing plaque and bacteria from the tooth surface. However, the hygienist can recommend a medium-soft brush, depending on your teeth.


Preference is given to brushes with a small head, because they can better reach all areas of the oral cavity, including hard-to-reach molars, which are deep in the oral cavity.

A toothbrush should be changed with signs of wear, and no less frequently than every three months, whichever is sooner. It is very important to change your toothbrush after illness a cold, because bristles can accumulate bacteria, which contributes to re-infection.

Doctors can stress the importance of flossing.


Sometimes the art of the dentist become the object of artists. For example:


Sometimes the teeth help the artist to create. Here is a paralyzed artist paints holding the brush in his teeth:


The fashion for clean healthy teeth is common. However, the fashion for the color and shape of teeth, especially its historical-geographical characteristics is able to surprise the modern man.

In the beginning of XIX century in Europe teeth were specially covered with a yellow dye to emphasize so fashionable at the time white skin.

The inhabitants of the island of Borneo believed that the teeth should be black. Preparing for holidays, they covered teeth with a special composition of a strip of banana leaf and left it for 40 hours. It was not impossible to drink or eat – the beauty demands victims! Then the long-suffering teeth were rubbed by the bark of a certain plant mixed with lime. However, black teeth are preferred at different times in Japan, Oceania, Indonesia, and India.


The people of Mesoamerica also sawed teeth. The form was completely different – triangular. The smile had to be like a smile of a shark. Therefore, enemies will be terrible.

Some people made holes in the teeth in order to add circles of copper or mother of pearl. Some people in India still consider it is necessary to decorate the front teeth by pieces of jade, obsidian, or other precious stones.

Modern dandies insert gemstones in teeth:


Teeth can also become the object of art, not only for aesthetic medicine. After all, some of the artists understand under the "perfect smile" teeth decorated with paintings, but not perfect dentition!


In addition, black-and-white images are called "tooth tattoo":


If we appeal to aesthetic medicine, the most important factor is correct selection of colors. Sergey Radlinski developed one of the most advanced technologies. The color of the tooth in the standard technique is obtained by matching the template palette. However, there is a downside. For example, the definition of color has occurred at 12 o'clock, and the man saw this color in a particular place at a particular time. In addition, in the evening or in the club it will be a different color.


Therefore, it was suggested to consider not only the criterion of color, but also transparency. The tooth consists of several layers. The first layer is the inner, then the dentine, and then a layer of enamel, the top layer is transparent enamel.

It is important to determine the degree of transparency of the tooth (high, medium, low). Moreover, age is important. The older a person is, the tooth becomes darker. To get the color map it is important to compare the age, transparency, and hue. In addition, using the minimum of materials, all possible colors are created, alternating in the order of the layers.

Lesson summary:


The content


The results of the lesson-case can be complemented by  findings of students



What three websites helped to find important information?





To help the student and the coach:





Where can you get information for the case?



















Location of the lesson:

The case-lesson takes place in the classroom.



Teams of boys and girls.

The score was:....


1. Give some examples of reactions for come calcium.
2. Calculate the tooth pressure of a Tyrannosaurus when it bites (for example, the tooth of circular cross section with a diameter of 8 cm).



Conduct a research. Try to make a description of your teeth (color, condition, etc.). You have to brush your teeth during the week using the rules that recommend by hygienists. Rate the teeth with the same parameters. Create a table: "the Original condition – Condition after cleaning according to the rules".



90 min (paired lesson)    


The possibility to conduct the lesson with a student-understudy  

It is possible.


The acquired knowledge and developed competence:

Knowledge about biological significance of the teeth, physiological and biological importance of calcium in the body.

Knowledge about the physical meaning of the pressure force on the example of the power bites.

Acquisition of hygiene skills and knowledge.



Tooth, decay, dentin, mineralization, bracket, pressure, calcium, enamel.



Hrabowska Larysa


Participated in the case upgrading:

Serhy Fedorin and the Institute of Yuri Moroz (www.shsd.ru)

The End

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