Functional properties of elements
Teeth perform several functions at once. Each element has a distinctive shape according to its purpose. The main role of the units is digestive. The quality of assimilation of useful elements by the body depends on the thoroughness of grinding the products. Only after chewing and moistening with saliva will the food be ready for subsequent processing by the digestive organs.
Chewing one piece lasts on average 10-20 minutes. The force exerted by the teeth on food sometimes reaches 80 kg. Incomplete dentition can lead to disturbances in the digestive system.
Another function of the elements is aesthetic. With malocclusion, a person may develop psychological problems, since the first thing others pay attention to during a conversation is a smile. Teeth also play a role in the formation of syllables. In the absence of one or more elements, the pronunciation of syllables changes: a lisp appears, speech is distorted.
Indicative
Teeth are an indicator of the general condition of the body. The presence of any metabolic disorders, chronic diseases of the endocrine, digestive and other systems, vitamin deficiencies, unbalanced nutrition - all this negatively affects the condition of the dentition - the teeth change their shade and begin to crumble.
Therefore, caring for your smile includes not only regular hygiene procedures and visits to the dentist’s office, but also treatment of concomitant pathologies.
As you can see from the article, teeth are not only about comfortable eating. The loss of at least one element of the dentition is fraught with possible problems with digestion, speech, as well as the development of complexes against the background of a cosmetic defect.
Tooth anatomy
The structure of all units is the same, but each tooth has a distinctive shape and dimensions, depending on the functions it performs.
Internal structure of teeth in the photo
What does a tooth consist of? The top layer (enamel) is predominantly composed of minerals. It protects the inner layers of the tooth from mechanical, thermal and chemical damage. The rest of the solid surface of the elements consists of proteins and liquid involved in metabolic processes. This layer tends to wear out and wear off over time. Typically, caries first affects the surface of the tooth. For this reason, you should carefully monitor the condition of the oral cavity and carry out hygiene procedures in a timely manner.
If you examine a tooth in cross-section, you can also see dentin. It also consists of mineral substances and protects the pulp with the nerve fibers located in it. Many small channels are localized in dentin, with the help of which metabolic processes in bone tissue are carried out. Through these structures impulses are transmitted between nerve endings. For 1 sq. mm of dentin there are about 70,000 microscopic tubules.
The internal cavity of the elements is represented by pulp. It consists of nerve endings and lymph nodes.
The structure of the tooth should be considered depending on its location relative to the gum. The visible part of the element is the crown. The area of contact between the tooth and the gum is called the periodontium. The root is located in a special cavity, which dentists call the alveolus. The root of the tooth ends at an apex, which is supplied with blood vessels. Through these structures, the elements are fed.
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What does the crown of a tooth consist of?
The part of the tooth that rises above the gum is not a monolithic piece made of homogeneous bone material. It is something like a nut in a shell. On top of the tooth is covered with a harder layer designed to protect against various influences - this is tooth enamel. And underneath it lies a softer and more vulnerable layer - it is called “dentin”. And even deeper, under the dentin, going into the root part, lies the “core” of the tooth - a cavity called the pulp.
Let's consider each component separately.
Enamel
Tooth enamel is de facto one of the hardest tissues inside the human body. Even large bones, designed to bear a load of tens of kilograms, are actually looser in structure than tooth enamel - after all, they do not need to constantly encounter various bacteria, constantly grind anything foreign (that is, food), and even collide with antagonist teeth.
Healthy enamel has a light (although not completely snow-white) color and a glossy surface texture; it is very smooth and dense.
Dentine
Dentin is also a type of bone tissue: that is, in an adult, dentin, like enamel, does not grow or change (unless we talk about cases of carious lesions). It is looser and more fragile compared to enamel - but it is still a “non-living” material that does not have nerves or capillaries. Dentin is something like a backup protective layer between the enamel and pulp.
Pulp
Under the dentin layer in the tooth there is a cavity, securely closed on all sides by hard “walls”. But this is not an “air bubble”, but a kind of chamber where the finest blood vessels and nerve fibers are concentrated. The pulp is very necessary during the period when the tooth is growing - all nutrients are transferred to it through this living core.
However, when a person becomes an adult and his teeth are finally formed, the role of the pulp ceases to be so important - it ceases to nourish anything. However, it may still be useful: after all, if the patient feels toothache, it means that it is the nerve fibers in the pulp that make it known about some kind of inflammation. However, when treating pulpitis, dentists often remove the pulp with all its contents - the adult patient’s tooth does not suffer from this, either functionally or aesthetically, and in the future such a pulpless tooth will definitely not cause pain.
Kinds
What are the units? Teeth in the oral cavity are divided into 4 types: incisors, canines, molars and premolars. The human jaw is symmetrical and each part (right and left) has the same number of elements. If this does not happen, then they talk about malocclusion development, which requires immediate correction.
Incisors
Incisors are the elements located in the center of the jaw. There are 8 such units in total - 4 at the bottom and 4 at the top. The peculiarity of the anatomy of the incisors is that they have a flat crown with a sharp cutting surface. There are 3 tubercles on the cuts of the incisors, which wear off over time. The centrally located elements are usually larger than the lateral incisors, since they bear more load when chewing food.
The upper central teeth are most susceptible to damage in the form of cracks in the enamel and chips. It is in these areas that aesthetic defects associated with improper placement of elements in the oral cavity and trema are usually noted.
Crown – part of the tooth protruding above the gum
It should be noted the main functions of the incisors are the primary capture of food, cutting pieces and chewing them. The central elements are the first to begin to chop the food and pass it further. Due to the sharp cutting edge, units and twos crumble and crush food for further normal absorption. The incisors protect the remaining elements from severe damage during chewing loads. In addition, they protect the digestive organs from the development of chronic diseases associated with insufficient absorption of nutrients by the intestines.
On the upper jaw, the units have impressive dimensions - up to 23 mm including the root system. Unit width is from 4 to 6 mm. Thanks to the flat crown, the chewing load is distributed evenly between all areas of the tooth. The thinnest enamel of the incisors is in the area of contact with the gum. It is this part that is most vulnerable to carious processes.
Several features of incisors should be noted:
- rounded root shape;
- the presence of grooves on the surface of the root;
- chisel shape;
- greater curvature of the incisors located on the sides.
Fangs
A person has 2 fangs on each jaw. They resemble a triangle in shape and are easily recognized among other elements of the series. With the help of fangs, a person can bite off pieces of hard foods - apples, carrots, crackers. The elements have only one long root. The upper units are larger than the lower ones. Some patients resort to extension procedures to give greater effect to the canines on the upper jaw.
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Premolars
The first premolar is also called a quadruple. The main function of the tooth is transitional and exciting. Due to the wider crown, the elements take part not only in biting off pieces of food, but also in grinding it to the desired state.
On the chewing surface of the element there are several types of chewing tubercles - flat and vestibular. The first tubercle is located closer to the cheek, and the last one is directed towards the oral cavity. In rare cases, three-tubercle or four-tubercle teeth are found. An anomaly is observed if the palatine tubercle passes into the median tubercle.
Due to the many grooves and fissures, pathogenic bacteria can accumulate on the surface of premolar teeth, especially if oral hygiene is insufficient. For this reason, these segments should be given the most attention when brushing your teeth. The second premolar of the upper and lower rows has larger dimensions, but is shaped like a quad.
Molars
Molars have the same structure as the rest of the series. But, despite this, several features can be identified that are characteristic only of sixes and sevens. The main function of molars is to grind and grind food during chewing. They play an important role in the formation of an anatomically correct bite.
Each half of the jaw has 4 molars below and above. Molars have several chewing surfaces. The buccal surface of the tooth is convex. There is a groove on it, which is a place where pathogenic flora accumulates. These areas also need to be given special attention when brushing your teeth, since the salivary glands are located near the buccal surface, which are affected during the development of carious processes.
There are 3 tubercles on the chewing surface: paracone, protocone and metacone. On the buccal side there is also the most important morphological structure of bone tissue - the Carabelli tubercle. The degree of expression of the structure is varied.
In some cases, the Carabelli tubercle may have its own process
The mesial border of the molars has a slightly convex shape. The root system on this side varies in shape among different patients. It can be cylindrical or barrel-shaped. The structure of the distal surface of the molars is similar to the mesial one. The only difference is inaccessibility during hygiene measures. For high-quality cleaning of the last elements, it is better to use floss or irrigator.
Wisdom tooth
Eight, or wisdom teeth, usually appear on the surface of the gums in adulthood. The shape of the element is similar to 6, but has more powerful roots. The number eight is considered the most problematic tooth: it is difficult to break through to the surface and quickly collapses. Dentists may have difficulty removing figure eights due to their abnormal position in the mouth and crooked roots, which can be diagnosed using x-rays. In such cases, the problem area is immediately extracted, otherwise purulent inflammation of the soft tissues may develop. Another serious complication of improperly positioned wisdom teeth is the destruction of the roots of adjacent units.
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Location
Fangs are among the paired elements of the dentition, located on the upper and lower jaws between the incisors and premolars. The development of permanent teeth begins in the fourth month of fetal formation, and is similar in structure to the process of formation of milk units.
The features that distinguish fangs from other elements of the series include:
- Single-root structure - the root part is characterized by an elongated shape, slightly flattened on the sides;
- A volumetric crown, which is characterized by the presence of two cutting edges that meet at the lowest point at an acute angle;
- The flat shape of the outer part, providing a connection at the edge of the vestibular and lingual surfaces;
- Larger size of the upper canine relative to the antagonist.
This structure is determined by the anatomical functions of the fangs, the task of which is to retain and divide food into separate parts.
Classification of dental surfaces
To conveniently describe the localization of the pathological process, dentists use a term such as “crown surface”. There are 4 types of such surfaces:
Where is the eye tooth + photo
- Chewable. This part of the tooth faces the elements on the opposite jaw. In canines and incisors, this area is represented by the cutting edge.
- Vestibular. Located in the vestibule of the oral cavity. The vestibular surface of the anterior teeth has an area of contact with the lips. In the molars, this part is in contact with the inner shell of the cheek and is called the buccal surface.
- Lingual or lingual - the area of elements facing the tongue. It is in this area that the largest amount of plaque accumulates due to the difficulty of carrying out hygiene measures. The lingual side of the elements is not visible to others during a conversation, so many patients seek to install corrective systems on the inside of the tooth.
- Approximal. This type of surface is divided into medial and distal. In the first case, the area is located closer to the middle of the dentition, in the second case, closer to the edge of the arch.
Tooth surfaces
Features of milk elements
Milk units act as precursors of permanent elements. They usually appear in the first year of a baby's life. Usually the period of eruption of the first incisors is accompanied by painful symptoms for the baby. About 2-3 years may pass between the appearance of the first and the eruption of the last milk tooth. A 3-4 year old child has 20 fully formed baby teeth in his mouth.
The structure of teeth in children
The change of the primary occlusion to a permanent one is carried out from 6-7 years of age. The shape of the permanent elements will differ little from their predecessors. The only difference is the more massive crown part and dense enamel.
In children, the degree of mineralization of enamel and dentin is weaker than in adults. Therefore, their dental care should be carried out with special care. The milk tooth is designed in such a way that most of its volume is occupied by the pulp, so caries in children becomes more complicated faster.
Another difference between milk units and permanent ones is short roots. For this reason, tooth loss in children sometimes occurs unnoticed and painlessly.
Teeth
Formations consisting mainly of hard bone tissue, located on the upper and lower jaws of a person.
Teeth perform the important function of chewing, contribute to the normal formation of speech sounds, and also serve as a barrier between the oral cavity and the external environment.
Teeth are the only part of the body that is not capable of self-healing. During a person's entire life, their entire dentition changes once. From the moment of teething at 2-3 years to 10-12 years, the child grows temporary, so-called milk teeth. At a certain age, temporary teeth fall out, and permanent teeth gradually emerge, which remain with us for life.
Features of the structure of teeth
Each tooth consists of a crown, neck and roots. In the neck area, the tooth narrows and the enamel layer ends at this point. The neck of the tooth is normally covered with gum and serves as a separator between the crown of the tooth and the root. With various diseases of the gums or periodontal tissues, the neck of the tooth may be exposed, and the tooth becomes sensitive and feels like it is aching.
The number of roots in different groups of teeth is not the same, it varies from one to three. Inside each tooth, under its hardest part - the enamel - there is dentin, a bundle of nerves and blood vessels.
Physiologically, a complete set of adult permanent teeth consists of 32 teeth - 8 incisors, 4 canines, 8 premolars (small molars) and 12 molars (large molars). Their combination on the upper and lower jaws makes up the dentition.
Incisors
Frontal (front), single-rooted teeth located in the middle of the dentition on both jaws. It is considered normal to have four incisors in the bite – two below and two above. Their main function in the chewing process is to grasp, bite, cut and tear food. During development, incisors can acquire the shape of a crown in the form of a spike, but such an anomaly today is easily treated: various operations are performed on modified spike-shaped teeth, which are easier to tolerate than on other teeth - they can be built up or removed depending on the specific situation.
Fangs
Frontal (front) teeth, in location they will be the third from the center of the dentition. The canines are located between the incisors and small molars (premolars). The crown height and root length of the lower canines are smaller than those of the upper canines. When chewing, they perform a role only in the initial stage, holding, biting food and tearing it into pieces. In terms of their functions, fangs can be compared to a chisel, and they are quite stable teeth - the pointed shape of the crown and elongated root ensure that they never have to be treated or removed.
Some people consider the upper canines to be special teeth and want to grow them. This procedure requires great determination, but the increased height of the canine crowns can negatively affect chewing ability.
Chewing teeth
These include small molars - premolars, as well as large molars - molars. They bear the greatest load during the chewing process. Premolars and molars are most adapted to chewing food, since they are more massive in structure and have a lumpy chewing surface. Chewing teeth are more susceptible to caries and pulpitis than others; in the practice of dentists, it is noted that they most often have to install dental crowns, and sometimes even a metal-ceramic bridge.
Wisdom teeth
This is the name of the extreme molars, the eighth teeth from the center, located at the level of the root of the tongue. There are four wisdom teeth in total - they are located on each side of the dentition on both jaws. Wisdom teeth got their name due to the late eruption of other permanent teeth, which occurs already in adulthood. For some people, wisdom teeth may not erupt throughout their lives or may not fully erupt.
When third molars erupt, pain may occur due to lack of space on the jaw. If the wisdom tooth grows in the wrong position and puts pressure on the neighboring tooth, then surgical intervention is resorted to.
The special science of dentistry studies teeth, and dentists of various specializations treat teeth and diseases of the oral cavity: therapists, orthopedists, surgeons, periodontists, orthodontists, hygienists.
Malocclusions
With a correct bite, the teeth of the upper jaw protrude onto the elements of the lower jaw by no more than 1/3. This position will make it easier for the jaws to chop food. Malocclusions are usually associated with the following conditions:
- The upper units overlap the lower ones by more than ½. This type of bite is usually called a deep bite.
- Certain groups of teeth may not fit together at all. In this case, they talk about an open bite.
- Distal bite. What it is? The problem is said to occur when the upper jaw is overdeveloped.
- If the lower jaw is pushed forward, then there is a mesial deviation.
- When the structures are displaced relative to each other, a cross anomaly occurs.
If not treated promptly, malocclusions can cause toothless jaws. For this reason, it is important to contact an orthodontist at the first sign of a problem.
