The structure of a human tooth in section

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The structure of a human tooth in section
The structure of a human tooth in section
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Teeth - a group of rigid organs located in the oral cavity. We use them to chew food into small pieces. They are also essential ingredients in speech production.

human tooth structure
human tooth structure

Main tooth structure

The structure of a human tooth can be divided into two main parts: the crown and the root. Above the gum line, the crown is the enlarged area of the tooth that is used for chewing. Below the gum line is an area of the tooth called the root. Thanks to the root, the tooth is held in the alveolar process of the jaw.

The outer surface of the root is covered with a bone-like mixture of calcium and collagen fibers known as cementum. The cement attaches the root to the surrounding alveolus.

Let's consider what a tooth consists of. We will not consider the structure of the human jaw (the teeth are located precisely on the jaw).

Each tooth is an organ consisting of three layers: pulp, dentin and enamel.

Pulp

Is the vascular area of the soft connective tissue in the middle of the tooth. Tiny blood vessels and nerve fibers enter the pulp through small holes at the tip of the roots to support the hard outer structures. Stem cells known as odontoblasts form the dentin at the margins of the pulp.

human wisdom tooth structure
human wisdom tooth structure

Dentine

Closest to the pulp, dentin is a hard, mineralized layer of tissue. Dentin is much harder than pulp due to the presence of collagen fibers and hydroxyapatite (a calcium phosphate mineral that is one of the hardest found in nature). Its structure is highly porous, allowing nutrients and materials from the pulp to spread throughout the tooth.

sectional structure of the tooth
sectional structure of the tooth

Enamel

Enamel - the white outer layer of the crown - forms an extremely hard, non-porous coating of dentin. It is the hardest substance in the body and is made from almost nothing but hydroxyapatite. The water content in enamel is only 2-3 percent. This part of the tooth requires daily care, otherwise it begins to darken. Also, it is the enamel that is destroyed in the first place in case of any dental diseases, since a huge number of microorganisms act on it daily.

the structure of the human teeth of the upper jaw
the structure of the human teeth of the upper jaw

The structure of the tooth in the section will be considered a little later.

Types of teeth

Teeth are divided into four main groups: incisors, canines, premolars and molars.

  • Incisors are pointed teeth at the front of the mouth with a flat apical surface for cutting food into smaller pieces.
  • Fangs are sharply pointed, cone-shaped teeth used for chewing tough material such as meat. They frame the incisors on both sides.
  • Premolars (small molars) and molars are large, flat-surfaced teeth located at the back of the mouth. Used for chewing and grinding food into small pieces.

Milk and permanent teeth

Children are born without teeth, but between the ages of six months and three years they grow a temporary set of twenty milk teeth (eight incisors, four canines and eight molars). Milk teeth fill the baby's tiny jaws and allow him to chew food. After about six years, the milk teeth slowly fall out and are replaced one by one by the permanent teeth.

Permanent teeth at this time are hidden in the upper and lower jaws. When such a tooth is cut, the roots of the milk atrophy. This causes it to eventually fall out. The child eventually develops a total of thirty-two permanent teeth.

How many teeth does a person have and where are they located

It has already been mentioned above that a person has 32 teeth. They are located in the upper and lower jaws from the midline of the mouth as follows: central incisor, lateral incisor, canine, first premolar (bivalve), second premolar, first molar, second molar and third molar. In dentistry, they are sometimes numbered (from the first to the eighth on the right and left sides, upper and lower; while the first tooth is the central incisor, and the eighth is the third molar, or wisdom tooth). There are a lot of options for numbering teeth used in dentistry, but we will not focus on this.

The first twenty-eight molars appear between the ages of eleven and thirteen. The third pair of molars, known as wisdom teeth, appear in the back of the jaw a few years later, early in adulthood, or may not appear at all. Since the third pair of molars are the same molars as all the others, the structure of a human wisdom tooth is no different from the structure of a regular molar.

Sometimes wisdom teeth bring little problems. For example, when they grow in the wrong position. In some situations, there is simply not enough room for them in the jaw. In both cases, wisdom teeth are removed surgically as their presence is optional.

Functions of teeth

Grinding (or chewing) is the main function of the teeth, but not the only one. Teeth are also needed to pronounce certain sounds. Also, do not forget about the aesthetic function - a smile looks rather strange without teeth.

Upper and lower jaw

The structure of human teeth in the upper jaw is exactly the same as in the lower. They are identical. The structure of the human upper teeth is designed so that the shape of one tooth coincides with the shape of its counterpart on the lower jaw.

Both the upper and lower jaws of a person have 14 permanent teeth plus a pair of wisdom teeth. The structure of a human wisdom tooth does not differ from the structure of a permanent one. But milk is a little different.

The structure of a human milk tooth

The milk tooth and its structure are slightly different from the usual. This is primarily due to the large size of the pulp cavity and the smaller size of the crown. Enamel and dentin are also slightly thinner than permanent teeth. Milk teeth are often exposed to harmful microorganisms due to the fact that their enamel is thin and easier to erode.

human molar structure
human molar structure

Dental diseases

Tooth decay and caries are important dental he alth problems. The enamel that covers the crown in every tooth can be eroded by acids produced by bacteria that live in the mouth and aid in the digestion of small pieces of food. This process of enamel erosion by acids is called decay. To prevent decay, good oral hygiene is essential, consisting of daily brushing and flossing. Decay can eventually lead to caries, in which holes appear in the enamel and endanger the dentin.

Tooth care

The whiter and he althier the teeth, the more beautiful our smile. But if you do not care for your teeth, they will eventually darken and generally collapse. To prevent this, it will be enough just to brush them twice a day with a brush and floss, as well as visit the dentist every six months. This is the whole secret of the beauty of teeth.

The structure of a human tooth: photos and drawings

the structure of the human upper teeth
the structure of the human upper teeth

Consider the structure of a human molar.

It should be noted that the figure above is a simplified cross-sectional diagram of a common molar. In fact, their relative size and proportions differ from tooth to tooth. Although the lower molars have two roots (as shown above), the upper molars usually have three. Purely for convenience and clarity of presentation in this scheme, the blood vessels are in one root of the tooth, and the nerves are in the other. But in fact, all tooth roots contain blood vessels, nerves, and lymphatics. The numbers in the picture correspond to the numbers in the table.

Part of a tooth Short description
The whole structure of a human tooth can be divided into two parts:
Main Structure
1. Crown The crown of a tooth is the part above the gum line and is covered with enamel.
2. Neck The neck of a tooth is the narrowed portion between the crown and the root.
3. Root A tooth root consists of one or more projections (two in the figure above) embedded in the bone. These tooth roots are found in the alveoli of the mandible or maxilla, depending on the location in the mouth of the individual tooth.
Detailed tooth anatomy
4. Enamel Tooth enamel is the hardest substance in the human body. It consists mainly of calcium phosphate and calcium carbonate. Enamel covers the crown of each tooth and is important because its hard structure protects the tooth from wear and tear, such as from chewing food. Tooth enamel is also a protective layer that shields the rest of the tooth structure from the damaging effects of acids that might otherwise attack part of the dentin.
5. Dentin The main structure of teeth is made up of dentin, which is a fossilized connective tissue. This gives the tooth its shape and rigidity.
6. Pulp The pulp is a soft connective tissue that is made up of blood vessels, nerves and lymphatics. It is contained within the center of the tooth, called the "pulp cavity".
7. Pulp cavity The pulp cavity of a tooth is the volume at the center of the tooth that contains the pulp (connective tissue that contains blood vessels, nerves, and lymphatics). Most of the pulp cavity is in the center of the tooth, but it also goes down through the roots. The narrow sections of the pulp cavity that run down through the roots of the teeth are called "root canals".
8. Desna The gum is nothing but the oral mucosa that surrounds the base of each tooth and jaw as a whole.
9. Blood supply Tiny blood vessels supply oxygenated blood and carry venous blood away from each tooth separately. They (shown in red and blue in the figure) are an integral part of the human vascular system and pass through dental root canals within each of the tooth roots.
10. Innervation Nerve fibers (examples of which are shown in yellow in the figure) are part of the human nervous system and run through dental root canals within each of the tooth roots.
11. Dental root canal Narrow channels of the pulp cavity extend from its center to the top of the tooth along each of the roots and are called root canals. Dental root canals contain blood vessels, nerve fibers and lymphatic vessels.
12. Cement

Cement is a calcium-rich layer that covers the root of a tooth. It is light yellow in color, slightly paler than dentin. Cement has the highest fluoride content of mineralized tissue. It is avascular, meaning that the cementum layer itself has no blood supply - hence no blood vessels passing through that part of the tooth.

The junction where cementum and tooth enamel meet is known as the cervical line.

13. Periodontal Ligament The periodontal ligament is the ligament that attaches the tooth to the alveolus. The periodontal ligament is composed of dense fibrous connective tissue that holds each tooth in position within the bone and acts as a mechanical shock absorber when the teeth are subjected to various mechanical forces while chewing food.
14. Apical foramen The apical foramen is located at the root of the tooth and is a small hole through which nerves, lymphatics and blood vessels enter the pulp cavity. Each tooth has as many apical foramina as there are roots (one, two or three, depending on the type).
15. Alveolar bone The alveolar bone is the thick part of the jaw bones, i.e. the lower or upper jaw, in which the alveoli of the tooth are located.

The table describes in detail the structure of a human tooth. As an example, served as a drawing, which shows a section of a molar tooth. The structure of the human front teeth (incisors) is practically no different, except perhaps only in the number of roots. Canine teeth are also similar in structure to molars and differ only in roots.

structure of the human jaw teeth
structure of the human jaw teeth

Since the structure of the tooth in the section cannot be conveyed by means of a photo, we will manage with the help of drawings and photographs of three-dimensional models of teeth. Above is a molar model and an incisor model. As you can see, their structure is practically the same.

The structure of a human tooth includes many more small particles - even each nerve bundle has its own name. We have considered a simplified version of the structure. It will be quite enough for a general acquaintance with the topic and in order to figure out how to care for your teeth and assess the degree of need for daily brushing.

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