Abstract: Objective: To investigate the role of Ssuh2 associated with dentin dyspepsia type I (DD-I) in the period of tooth germ development in mice. Methods: The time of E13.5d, E14.5d, E16.5d, P2.5d, and P7d were determined by HE staining. The expression of SSUH2 was observed by immunohistochemistry. Results: During the bud stage (E13.5d), SSUH2 was positively expressed in epithelial cells and mesenchymal cells. During the cup period (E14.5d) and the early bell stage (E16.5d), SSUH2 was strongly positively expressed in the basement membrane, internal and external epithelium, enamel knot, and cervical loop. During the cell differentiation and secretory stage (P2.5d) and mineralization stage (P7d), SSUH2 was strongly expressed in ameloblasts, odontoblasts, enamel, and epithelium root sheath. Conclusion: SSUH2 was expressed during all stages of mouse tooth germ, however, the expression of SSUH2 was slightly different in each period. SSUH2 might involve in the development of tooth germs in mice.

Key words: SSUH2, Dentin dysplasia, Tooth germ development, Immunochemistry