Emperor Qianlong was the emperor who reigned for the longest time and lived the longest in Qing Dynasty. One of the secrets of his longevity was "knocking his teeth frequently". Knocking teeth, also known as "ringing the bell", was a very popular regimen in ancient China. There is a saying in the folk proverb that "three hundred and sixty teeth can be knocked at once, but seven old people can't lose eighty teeth."
From the perspective of traditional Chinese medicine, saliva will increase in the process of knocking teeth, while traditional medicine believes that saliva can nourish the five internal organs. Modern medicine has also proved that saliva contains a variety of substances related to life activities, which can not only promote digestion and absorption, but also play an important role in nourishing yin and reducing fire, promoting fluid production and tonifying kidney, moistening skin and hair, and dredging joints and orifices.
Sufficient kidney essence, so the teeth are strong and not easy to fall off; Insufficient essence in the kidney, teeth are easy to loosen, and even fall off early. Tapping teeth can strengthen teeth and replenish kidney essence, so it can strengthen the kidney. The main function of knocking teeth is to strengthen teeth. If the teeth are healthy, food will be easy to chew, and the burden on the stomach will be reduced, thus achieving the effect of nourishing the stomach. The saliva produced by tapping teeth can reduce the burden on the spleen and stomach, thus achieving the purpose of strengthening the spleen and stomach. Teeth and bones are homologous and nourished by kidney essence. Percussion can replenish kidney and essence, which will naturally be beneficial to bones. Perseverance will inevitably achieve the function of strengthening bones.