人都说“老掉牙”,其实人老未必掉牙,从人体生理学上讲,牙齿的脱落并不是年老的必然结果。虽然随着年龄的增长,人体器官会逐渐衰退,功能减弱,但也是相互协调平衡的,不应出现个别器官早期损伤现象。器官的损伤是个病理现象,牙齿也是这样,掉牙是长期牙颌病损累积的后果。从社会调查中我们会看到,不少八九十岁的老年人牙齿是完好的, People say “old-fashioned teeth”, in fact, old people may not fall off teeth, from the human physiology, the loss of teeth is not the inevitable result of old age. Although with the growth of age, human organs will gradually decline and their functions will be weakened, but they will also be in harmony and balance with each other. There should be no early injury of individual organs. Organ damage is a pathological phenomenon, the same is true of the teeth, tooth loss is the cumulative effect of long-term dentition lesions. From the social survey, we can see that quite a few elderly people in their 80s and 90s are in good condition,