Objective: To explore the histological structure of the deciduous teeth and the tooth germs of Tibetan miniature pigs for studies of dental tissue diseases and tooth regeneration.
Methods: The structure of the deciduous teeth of Tibetan miniature pigs was observed by X-ray. The ultrastructure of the enamel and dentin of deciduous teeth was characterized by scanning electron microscopy. The jaws and teeth were three-dimensionally reconstructed using Mimics software based on Micro-CT scanning of the deciduous teeth. Image J software was used to calculate the gray value and the mineralization density of the deciduous teeth. Hisotological structure of the tooth germ and the pulp tissue of Tibetan miniature pigs was observed using HE staining.
Results: The deciduous teeth of Tibetan miniature pigs were composed of enamel, dentin and medullary pulp tissue. The permanent tooth germ were formed during the deciduous dentition. The enamel and dentin ultrastructure of deciduous teeth were consistent with that of human deciduous teeth. The enamel and dentin mineralization densities were 2.47±0.09 g/cm3 and 1.72±0.07 g/cm3, respectively. The pathological structures of tooth germ and pulp tissue were similar to those of human teeth, and the pulp tissue of the deciduous teeth was in an undifferentiated state.
Conclusions: The deciduous teeth of Tibetan miniature pig have similar anatomy, ultrastructure and histopathological structure to human teeth and can serve as a good animal model for studying human dental tissue diseases and the mechanisms of tooth regeneration.
目的: 探索西藏小型猪乳牙牙体及牙胚的组织病理结构特性，为牙齿相关疾病及牙再生研究奠定基础。
方法: 通过X线拍摄西藏小型猪乳牙牙牙合系统结构，扫描电镜观察其乳牙牙釉质及牙本质超微结构，采用Micro-CT对乳牙进行扫描，Mimics软件对颌骨及牙齿进行三维重建，进一步应用Image J软件计算灰度值及计算乳牙矿化密度值，通过HE染色了解西藏小型猪牙胚及牙髓组织结构特点。
结果: 西藏小型猪乳牙牙冠由牙釉质、牙本质及牙髓组织构成。乳牙牙釉质和牙本质超微结构与人类乳牙较一致，牙釉质和牙本质矿化密度值分别为2.47±0.09 g/cm3和1.72±0.07 g/cm3，牙胚和牙髓组织病理结构与人类牙齿结构也较一致，乳牙牙髓组织处于未分化状态。
结论: 西藏小型猪的乳牙解剖、超微结构、组织病理结构均与人类相似，是研究人类牙体组织疾病发病及牙再生机制理想的动物模型。
Keywords: Tibet miniature pigs; deciduous teeth; laboratory animal model; tooth germ.