牙是人体中最坚硬的器官。外部包围着坚硬的壳壁,中央是囊腔,其中充满着血管、神经、结缔组织和淋巴液。因此牙齿不是植立在齿槽骨内的“死石块”,而是有感觉有生命的生活器官。成人32个牙齿(儿童20个)以齐整的队列并排植立在上下頜骨上,它们以集体的阵势把守着消化道的开口,完成着把食物切断、咬裂、割碎、磨烂的使命。牙齿的咀嚼力大得惊人。以专用仪器测量,普通成年男人的一对最小的门矛,其垂直咀嚼压力在15千克左右;垂直咀嚼压力最大的第一大臼齿竟可达72千克。平均成年男子的32棵牙齿的垂直 Teeth are the hardest organs in the human body. The exterior is surrounded by a hard shell wall and in the center is a cyst, which is filled with blood vessels, nerves, connective tissue and lymph fluid. Therefore, the tooth is not a “stone block” planted in the alveolar bone, but a living organ that feels alive. Thirty-two adult teeth (20 children) sit side by side in the neat queue on the upper and lower jaws. They guard the opening of the alimentary canal in a collective position and complete the task of cutting, cracking, slicing, and grinding the food. . The chewing force of the teeth is amazing. Measuring with a special instrument, a pair of the smallest door spears of an ordinary adult man had a vertical chewing pressure of about 15 kilograms; the first largest caries, which had the highest vertical chewing pressure, could reach 72 kilograms. 32 vertical teeth of the average adult man