动物造模 z-bio 2022-06-07 609

　　Objective: To understand the developmental timing characteristics of the mandibular first molar tooth germ in ICR mice, and to provide an experimental basis for using mice to study the mechanism of tooth development and related influencing factors.

　　Methods: E (embryo) 11.5, E12.5, E13.5, E14.5, E15.5, E16.5, E17.5 and E18.5 d fetuses and PN (postnatal) 2 d were taken. The heads or mandibles of newborn mice were fixed, decalcified and embedded, then serially sectioned, stained with HE, and observed and recorded under a photomicrography system to analyze the dynamic changes in the development of molar tooth germs in ICR mice.

　　Results: E11.5 d was the beginning of tooth germ development, E12.5 d, the tooth germ transitioned to bud stage, E13.5 d entered bud stage, cap stage was E14.5～E15.5 d, bell stage Beginning at E16.5 d, the tooth hard tissue began to form gradually at 2 d after birth.

　　Conclusion: ICR mouse embryo 11 d to postnatal day 2 is the best time to study the development mechanism of mandibular first molar tooth germ.