ABSTRACT
Objective To study the process and mechanism of embryonic development and replacement of the teeth of Alligator sinensis. Methods The proccess of embryonic development and replacement of the teeth of Alligator Sinensis was studied by paraffin serial sections, the structure of the teeth of Alligator sinensis was studied by scanning electron microscopy. Results The tooth wrinkle appeared at the 20th day of incubation; the dental germ appeared at the 56th day of incubation; the crown appeared, and the dental germ came into the bottom of the alveolus dentalis at the 16th day after the young alligator was out of the eggshell. From one year to five year alligators, there was a dental germ at the bottom of the alveolas dentalis that would form new tooth after the old tooth was lost. Conclusion The tooth wrinkle might motivate embryonic development of the teeth of Alligator sinensis ; the dental germ at the bottom of the alveolus dentalis formed directly the new tooth in the process of tooth replacement. [