动物造模 z-bio 2021-11-30 820

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

　　Method: Take E (embryo) 11.5, E12.5, E13.5, E14.5, E15.5, E16.5, E17.5 and E18.5 d fetus and PN (post-birth) 2 d. The heads or mandibles of newborn mice were fixed, decalcified and embedded in serial sections, then stained with HE, and observed and recorded under a photomicrograph 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 tooth germ transitioned to bud phase, E13.5 d entered bud phase, cap phase was E14.5～E15.5 d, bell phase Starting at E16.5 d, hard tissues of the tooth began to form gradually 2 days after birth.

　　Conclusion: From the 11th day of ICR mouse embryo to the 2nd day after birth is the best time to study the developmental mechanism of the mandibular first molar tooth germ.