Teeth grow in the alveolar fossa, around which there are periodontal ligament, alveolar bone and gum. These three tissues are collectively called periodontal tissues, which are the supporting tissues of teeth.
Periodontal membrane is a dense connective tissue, which grows between alveolar bone and root. It surrounds the root of the tooth, making the tooth grow firmly in the alveolar like a ligament. Periodontal membrane fibers have certain elasticity and can adjust and buffer chewing pressure. When the periodontal ligament is diseased or damaged, the fiber breaks and the teeth become loose.
Alveolar bone is the protruding part of the jaw around the root, and the root is firmly buried in the alveolar fossa formed by alveolar bone, so it is the main tissue for supporting teeth. When the tooth comes out, the alveolar bone grows out, and when the tooth falls off or is pulled out, the alveolar bone is gradually absorbed. If the alveolar bone is broken due to trauma or atrophied and absorbed due to illness, the root will be exposed and the teeth will be unstable.
Gingiva is an oral mucosa covering alveolar bone and tooth neck, which is rich in blood vessels. Healthy gums are pink, flexible and elastic, and can tolerate the friction of food. The gingival papilla between two teeth is called gingival papilla, and the gap between gum and tooth neck is called gingival sulcus, which is normal.
More than 2 mm, if the gingival sulcus is too deep, there will be symptoms such as inflammation and pus overflow, which is periodontitis. Healthy periodontal tissue plays an important role in maintaining teeth. Periodontitis can lead to teeth
The absorption of sulcus bone can destroy periodontal ligament, make teeth loose, and finally develop to the point where teeth fall off on their own.
What structure does a tooth consist of?
Teeth are composed of enamel, dentin, cementum and pulp. The part of the tooth exposed to the mouth is called the crown, and the part surrounded by the gum is called the neck, which is buried in the alveolar cavity.
The part inside the bone is called the root. The outermost layer of the crown is enamel, translucent white, shiny and the hardest.
Tooth tissue. Next to the inner surface of enamel is dentin, which constitutes most of the teeth and is slightly lighter in color than enamel.
Yellow contains less inorganic salts than enamel, so its hardness is not as good as enamel, but it is still harder than bone tissue. The yellow color of dentin yellows teeth through enamel. Dentin consists of matrix and dentinal tubules passing through the matrix. The inner end of dentinal tubule is connected with odontoblasts, and the pulp nerve enters dentin, so dentin is more sensitive than enamel. If dentin is exposed due to dental caries or trauma, dentin allergy will occur.
The surface layer of root tissue is called cementum, and its main function is to embed one end of periodontal ligament fibers and fix teeth in alveolar fossa with the help of periodontal ligament fibers. Cementum is a thin layer of yellow tissue, accounting for only a small part of tooth tissue. It can be divided into cellular cementum and acellular cementum. Cementum has a strong regenerative ability. When it is destroyed, it will differentiate from cells in connective tissue into cementum cells, and then form cementum.
There is a small cavity in the center of the tooth, called pulp cavity, which contains nerve blood vessels and nerve blood of the whole body.
The pipes are connected. The nerves and blood vessels in the medullary cavity are called medullary tissue, and the nerves in the medullary cavity can conduct feelings. When treating teeth, the pain of molars is transmitted through dental pulp tissue. Blood vessels are connected with the blood circulation of the whole body, which makes teeth energetic. In addition to nerves and blood vessels, there are odontoblasts in dental pulp, which are connected with dentinal tubules. Tooth-producing cells continue to form dentin in people's life. With the increase of people's age, the volume of pulp cavity becomes smaller and smaller. The cell and fiber components in dental pulp tissue also change with the increase of human age, that is, the younger the age, the more cell components and the stronger the regeneration ability.