怎样保护牙齿英文版的

In order to protect the teeth, we must first understand the structure of teeth. Human teeth is the most solid organs. There are bite cutting, tearing, grinding food and to assist the functions of pronunciation. One's life has two teeth: one for the deciduous teeth, a total of 20, the lower jaw of the 10. About six months after birth around the beginning of the eruption, about a two-year-old semi-homogeneous, since the period of 7-12 years of age, shedding of deciduous teeth after another; another deputy for the permanent teeth, a total of 32, the lower jaw of the 16, since the 6-year-old from gradually to the replacement of deciduous teeth, in addition to 12-year-old before and after the first 3 molars, the eruption of permanent teeth all. No. 3 in the 20-year-old molars in general after the eruption, also known as wisdom teeth. Wisdom can also be no life, so 28 to 32 permanent teeth are normal.

Sub-crown tooth, dental root neck and three parts. Crown that is, we can