Tooth germ facts for kids

Radiograph of lower right (from left to right) third, second, and first molars in different stages of development.

X-ray of teeth of a boy aged 5 years showing left lower primary molar and developing crowns of left lower permanent premolar (below primary molar) and permanent molars.

Tooth development or odontogenesis is the complex process by which teeth form from embryonic cells, grow, and erupt into the mouth. For human teeth to have a healthy oral environment, all parts of the tooth must develop during appropriate stages of fetal development. Primary (baby) teeth start to form between the sixth and eighth week of prenatal development, and permanent teeth begin to form in the twentieth week. If teeth do not start to develop at or near these times, they will not develop at all.