There are two pairs of natural teeth in a person's life, one is deciduous teeth and the other is permanent teeth. When deciduous teeth fall out, permanent teeth grow out. Permanent teeth cannot regenerate after falling off.
With the progress and development of social science and technology, denture has become the third pair of human teeth.
In daily life, people talk loudly and chew food through the cooperation of teeth. At the same time, the health and beauty of teeth are closely related to people's daily life.
Chinese name: Tooth mbth: Main components of teeth: calcium classification: anatomical "teeth" of natural teeth, deciduous teeth and permanent teeth, morphological structure, classification, teething, arrangement and quantity of teeth, causes of tooth loss, clinical marking of teeth, dental care, tooth whitening, dental care for children, protection of children's six-year-old teeth, and morphological structure of each anatomical "tooth". The crown is the part exposed outside the gum, white and shiny; The root of the tooth is embedded in the alveolar bone and firmly connected with the alveolar bone through periodontal ligament. There is a hole in the apical part of a tooth, which is called apical foramen. It is connected with the cavity of dental crown through root canal, which contains blood vessels, nerves and lymphatic vessels. The neck of a tooth is a slightly thinner part between the crown and the root, which is covered with gums. Periodontal membrane, alveolar bone and gum are collectively called periodontal tissues, which have protective, fixing and nutritional effects on teeth. Morphology and structure of teeth The structure of teeth is mainly composed of dentin, enamel, cementum and pulp. Dentin is dense and hard, which constitutes the main body of the tooth and is located inside the tooth. There is a layer of adhesive (cementum) outside the dentin at the root of the tooth, while the surface of the crown has white, bright and hard enamel. Enamel has the highest degree of calcification and is the hardest tissue in human body. Crown cavity and root canal are collectively called dental cavity, which is filled with blood vessels, nerves, lymphatic vessels and connective tissue, and is called dental pulp. Lactobacillus in oral cavity can ferment sugar to produce acid, which leads to decalcification of enamel and tooth cavity, which is called dental caries clinically. If the cavity deepens and spreads to the nerve of the pulp, it will cause severe pain. According to the different shapes and functions of teeth, permanent teeth can be divided into incisors, canines, premolars and molars. Primary teeth are divided into deciduous incisors, canine teeth and deciduous molars. Types and arrangement of teeth 2 Classification and arrangement of teeth 1 A front tooth is a single tooth with a flat chisel crown, which is mainly used for occluding food; Tusks are also single teeth, and their crowns are vertebral, which are used to bite and tear food; The premolars are generally single-toothed, and the crowns are approximately square to assist the molars in grinding food; Generally, molars have three upper jaws and two lower jaws, and their crowns are square, which are used to grind food. Teeth in a person's life, there have been two groups of teeth. The first pair of deciduous teeth, ***20. It began to germinate about 6 months after birth and basically grew up at the age of 3. The second set of permanent teeth, ***32. From the age of 6, deciduous teeth began to fall off gradually, and permanent teeth began to erupt (the first molar of permanent teeth is usually around 5 years old, and deciduous teeth began to erupt from the outside of the second molar of deciduous teeth before falling off). But not deciduous teeth. Except the third molar, the other 28 teeth usually erupt at the age of 12- 14. The third molar erupts late, and its age is 18-30, so it is also called delayed tooth or wisdom tooth. Some people never erupt or partially erupt (all ***4), so the number of permanent teeth ranges from 28 to 32. Permanent teeth are a person's last pair of teeth. After the permanent teeth fall off, there will be no teeth eruption in the fallen part. The arrangement and number of teeth from front to back are 5 deciduous teeth, 2 incisors, fangs 1 tooth and 2 molars on the left and right sides of the maxilla, respectively, with a total of 20 teeth. There are 8 permanent teeth on the left and right sides of the maxilla and mandible, including 2 incisors, 1 canine, 2 premolars and 3 molars from front to back, a total of 32 teeth. Reasons for tooth loss, such as tooth tissues are mostly hard objects, and hard objects such as sand may be bitten after trauma, such as collision or occlusion trauma; It may also be that after rotten teeth are necrotic, the tooth tissue becomes brittle and easy to break off due to lack of blood supply. Must have a history of toothache, oral examination can find tooth decay. Clinical marking of teeth is to quickly, accurately and simply record the position of each tooth in the oral cavity. It is often based on the position of candidates, with horizontal lines indicating the dividing line between the upper and lower dentition and vertical lines indicating the dividing line between the left and right sides, that is, the "cross" mark to divide the four areas; Roman numerals I ~ V are used for primary teeth, and Arabic numerals 1~8 are used for permanent teeth. The purpose of tooth whitening ultrasonic cleaning is to remove dental calculus. Because dental calculus is more likely to cause the accumulation of dental plaque, leading to gingivitis and periodontal disease. Therefore, removing stones is a medical act. Of course, at the same time of treatment, the teeth will be whitened when the stones in the neck and adjacent surfaces are removed. The disadvantage of tooth washing is that it is more painful and produces more blood, and the surface of teeth is rough after washing, and dental plaque reappears faster. Finally, you may get sick. Plasma tooth whitening is the same as applying peroxide drugs on the surface of teeth. It is inactivated by plasma irradiation and catalyzes the redox reaction of drugs, thus achieving the effect of tooth whitening. Each course of treatment is about 1 hour, and it must be conducted in a dental clinic. All courses of treatment are 3 ~ 5 times, achieving the whitening effect that ordinary patients want. It usually makes the upper and lower rows of front teeth, and the buccal side. Four teeth on each side, 16 teeth, up and down or so. Laser tooth whitening is a special catalyst catalyzed by high concentration bleaching agent (H2O2-H2O2) with appropriate laser dose to enhance the bleaching effect of hydrogen peroxide, and bleach the organic pigment in teeth from carbon ring structure to hydrophilic pigment-free structure, thus achieving the effect of safe whitening. 2 1 century, I'm afraid it's your best choice for all you who stress speed and efficiency. It's OK once. A course of treatment is about 3 hours. Similarly, it must be done in the dentist's office. There are 16 teeth in front of the upper and lower rows, with buccal side. Although hydrogen peroxide drugs are used to treat tooth whitening. It is more or less harmful to the tooth itself and periodontal soft tissue, but it is within the controllable range, so don't worry too much. The discomfort of teeth and soft tissues will return to normal in about 3 ~ 6 days. The method of removing tartar vinegar is to take a vinegar mouth, put it in your mouth and spit it out for two or three minutes, then brush it with a toothbrush, and finally rinse your mouth with warm water. Or when brushing your teeth, drop two drops of vinegar on the toothpaste to brush your teeth, and stick to it for a while to remove tartar. Brush your teeth with brown sugar: First, put a proper amount of brown sugar into your mouth for about 65,438+05 minutes, so that all teeth are immersed in the sugar solution, then brush them repeatedly with a hard toothbrush for two or three minutes, and then brush them with light salt water for one or two minutes, 65,438+0 times in the morning and 65,438+0 times in the evening, which can be extracted continuously for 65,438+0 weeks. (Special note: This method is not advisable. If you brush your teeth with yeast and vinegar, your teeth will turn white in a short time. But this is the temporary whitening of enamel due to wear. Over time, teeth will get darker and darker, and it will cause permanent damage to teeth, so it is not recommended to whiten teeth in this way. Children's dental care should develop good living habits and let the baby care for his teeth. First of all, many babies like to spit and bite their tongues. This habit must be corrected. The habit of sticking out the tongue and biting the tongue makes the erupted teeth blocked by the tongue, and the upper and lower incisors can't touch each other, resulting in abnormal opening of the incisors. In addition, some babies also like to lick their teeth with their tongues, which will only lead to the crown leaning forward and fanning out, and the upper and lower lips are not easy to close, showing the deformity of "opening lips and showing teeth". Children who like to bite their fingers and pencils should also be strict about changing this bad habit. Prevention It is very important for children to have neat and healthy teeth. During the fetal period, expectant mothers should supplement enough nutrition as required by doctors, such as vitamins, calcium and protein, which play an important role in the generation of fetal teeth. In addition, pregnant women should strictly prevent colds and prevent tooth germ development or other diseases that affect the fetus. In infancy, be careful not to let the baby develop bad habits such as eating fingers, chewing towels and containing pacifiers, which are easy to make the baby's teeth develop in a bad direction. The protection of children's six-year-old teeth refers to the eruption of molars around 6 years old, which is called the first permanent molar. Life is irreplaceable. It occupies a very important position in the occlusal system and bears the greatest chewing function. Once missing, it will destroy the occlusal balance and reduce the chewing function. Because of the anatomical characteristics of the first permanent molar, it is very easy to have dental caries within 2-4 years after eruption, so attention should be paid to protection. First, we must go to the hospital for pit and fissure sealing to prevent dental caries; Second, check it regularly and treat it in time once you have dental caries. Eat more coarse food, increase the self-cleaning effect of the mouth and the * * * effect on the gums, and at the same time make the jaw develop normally through the physiological * * * produced by chewing. Get into the habit of not eating snacks and brushing your teeth before going to bed. Primary and middle school students should pay attention to maintaining good oral hygiene and correct bad habits such as unilateral chewing, mouth breathing, lip sucking, pencil biting and finger biting. If there is tooth deformity or crowded dentition, it should be corrected in time.