A histological study of tooth germ transplant into nude mouse

Objectives: To establish an innovative experimental model the change of the developed mouse's dental germs after grafting was observed in vivo. Methods: Eight tooth germs of five-day-old postnatal Balb/c mice were super muscule- transplanted to adult nude mice. At the first, second, third, fourth week after grafting, the germs were collected, fixed, demineralized, dehydrated, and embedded in wax. Serial sections of 5um thick were made following the routine methods, stained with haematoxylin-eosin dying solution, and observed under a light microscope. Results: All implantations located in the super muscule with abundant capillary vascular and no obvious inflammation was seen. The dental germ seemed further developed under the microscope: plenty of dentin with disorganized dentin tubule was formed, the roots began to formed but obviously slower than those of self-development, the floor of pulp chamber could form and the pulp chambers were shrinking, and the degree of calcification in the area of root increased very clearly. The inflammatory reaction was found from two weeks and on after grafting but only limited in the crown of the tooth germ. Conclusions: It suggests that late development of mouse tooth germs could be further develop in short-term while lose their normal shape in long-term after heterotopic placement within super muscule of nude mouse . Supported by National Natural Scientific Foundation of China. 30371537 and Shandong Provincial Excellent Young Scientist Scientific Foundation.02BS096.