The Expression And Significance Of Matrix Metalloproteinase 9 During The Replacement Of Of Dogs' Primary And Permanent Teeth

With the development of permanent teeth germs, primary dental roots begin to be absorbed, primary dental crows fall off, then the primary teeth are replaced by permanent teeth, this process is called replacement of primary and permanent teeth. It is a normal physiological phenomenon in children oral cavity. The formation of erupt pathway and resorption of primary dental roots are the prerequisite of teeth eruption and replacement. Osteoclasts take part in these processes and play an important role. So it is significant to study the activation, differentiation and expression of osteoclasts for understanding and control teeth eruption and replacement.Osteoclast was first reported by Kolliker in 1873. Their diameter is about 100μm, contains 2-100 karyons. They mainly distribute on the surface of bone, around the channels of blood vessels. Osteoclasts are the multinucleated giant cells that participate in bone-resorbing. They originate from hematopoietic stem cells of marrow and spleen and flow to the sites where osteoclasts act actively. Both monocytes in marrow, in outer blood vessels and matured macrophages in tissue can transformed into osteoclasts in special conditions.