The replacement of teeth usually starts with the incisors, followed by the molars, and there is a symmetrical pattern of tooth replacement. Usually, when a child is six years old, the replacement of teeth begins with the lower middle incisors, then the upper middle incisors, then the lateral incisors on both sides, followed by the cuspids and the tiger teeth, which are replaced in a different and irregular order, and then the replacement of the first molar and the second molar, in that order, is completed. At the beginning of the tooth replacement period, the first permanent molars, or six-year-old teeth, come in. By the time the child reaches the age of 13 or 14, the process of tooth replacement is basically complete. It is important to note that during the tooth replacement period, it is important to stick to the good habit of brushing every day to minimize bacterial growth that can harm the new teeth. At the same time to pay attention to the process of tooth replacement, it is recommended that every six months or so for oral examination, timely understanding of the situation of tooth replacement, in order to prevent the emergence of abnormal phenomena.