中文摘要：

目的：观察胚胎期及出生后小鼠牙胚与牙槽骨之间距离变化，为研究小鼠牙槽骨发育提供形态学基础。方法将实验用小鼠分成两组：I 组包括胚胎期（E15.5、E16.5、E17.5、E18.5）小鼠头部行组织学处理后冠状面切片，II组包括出生后（PN1.5、PN3.5、PN5.5、PN7.5、PN10.5、PN15.5和 PN30.5）小鼠单侧上颌骨组织学处理后行失状面切片，分别测量牙胚与牙槽骨之间距离后进行比较。结果小鼠出生前牙胚根尖1/3区域与周围骨质之间距离宽度呈递减趋势，而出生后则呈递增趋势；出生后近中牙尖区域此宽度随着牙胚的发育整体呈递减趋势。结论在牙周组织的发育过程中，牙囊细胞起到关键性的作用，它和牙源性上皮相互协作形成牙槽骨，这就导致了牙胚和牙槽骨之间距离随着牙胚的发育而发生着变化。

英文摘要：

Objective To provide the morphological basis for alveolar bone development,we observed the change of distance between the tooth germ and alveolar bone of mice. Methods After histological processing,the head of embryonic mice（E15. 5,E16. 5,E17. 5 ,E18. 5 and PN0. 5）were made into sagittal sections and the post natal ones（PN1. 5,PN3. 5,PN5. 5,PN7. 5,PN10. 5,PN15. 5 and PN30. 5）were made into coronal sections. Results The distance between the apical 1 / 3 of root and alveolar bone is a descending tendency of embryos,but it is an in-crease trend of post natal ones. The distance between the mesial cusp and alveolar bone has a descending tendency. Conclusion During the de-velopment of periodontal tissue,dental follicle cells played a critical role. The alveolar bone developed form dental follicle cells. Dental follicle cells interacted with odontogenic epithelial cells result in the difference of distance between tooth germ and alveolar bone.