Have two pairs of teeth all one's life, namely deciduous teeth (in all 20) He Hengya (in all 32) . Since 6 months (4 ～ 10 months) begin teething, 2.5 annual expenditure of 2 ～ are neat. Month of = of gross of deciduous teeth of the children inside 2 years old age - (4~6) , be like teething of 14 months children 8 ～ 10. 12 months have not teething can regard as unusual, see at illness of more serious bring down of hidebound, rachitic, thyroid function, 21- 3 body syndrome. Teething order sees a picture.

6 years old or so begin to give tooth of the first constant, namely the first grind one's teeth, long after grind one's teeth of the 2nd breast. 7-8 year old begin deciduous teeth to go out by bud early or late one by one falls off acting with constant tooth, among them the 1st, 2 pairs of fang are replaced the 1st, 2 breast grind one's teeth. 12 annual expenditure the 2nd grind one's teeth, the 3rd indulge in idle talk gives after 18 years old (also have lifelong do not give this tooth) . 20-30 annual expenditure is neat (in all 32. )

Unripe tooth is physiology phenomenon, but exceptional children can have increase of low heat, saliva, produce the symptom such as salivate and Morpheus uneasiness, be agitated.