Ishizeki K, Fujiwara N, Sakakura Y, Nawa T
Department of Oral Anatomy, School of Dentistry, Iwate Medical University, Morioka, Japan.
Arch Oral Biol. 1987;32(10):695-704. doi: 10.1016/0003-9969(87)90112-9.
Tooth germs taken from 13-day-old embryonic mice and isografted in the spleen of adult mice were examined by light and electron microscopy. Well-organized tooth structures from the early cap stage to fully developed and mineralized mature teeth were obtained up to day 60 after transplantation. Germs on day 2 were similar to those prior to the onset of grafting but reached the late cap stage of development on day 4. On day 6, enamel and dentine formation were initiated and inner enamel epithelium and dental papilla cells were polarized. On days 10-15, enamel-matrix secretion was completed and almost all ameloblasts had become resorptive enamel epithelium. India ink injected from the recipient caudal vein accumulated to the capillaries within the pulp throughout the newly-formed vessels. On day 20, defined root formation had begun but occasionally irregular and cellular osteodentine was formed in root areas. On day 30, transplants were covered with reduced enamel epithelium and acellular cementum was formed at the root areas together with rudimentary periodontal ligament fibres. Cellular cementum became thicker up to day 40. There was little evidence of cellular infiltration from recipient tissue up to day 60. The spleen seems to be a suitable site for transplantation of tooth germs.
从13日龄胚胎小鼠获取牙胚，并将其异位移植到成年小鼠的脾脏中，通过光学显微镜和电子显微镜进行检查。移植后60天内可获得从早期帽状期到完全发育并矿化的成熟牙齿的结构完整的牙齿。移植后第2天的牙胚与移植前相似，但在第4天进入发育的晚期帽状期。第6天，开始形成釉质和牙本质，内釉上皮和牙乳头细胞极化。在第10 - 15天，釉基质分泌完成，几乎所有成釉细胞都变成了吸收性釉上皮。从受体尾静脉注射的印度墨汁在整个新形成的血管中积聚到牙髓内的毛细血管中。第20天，明确的牙根形成开始，但牙根区域偶尔会形成不规则的细胞性骨样牙本质。第30天，移植牙被缩余釉上皮覆盖，牙根区域形成无细胞牙骨质以及原始的牙周韧带纤维。到第40天，细胞性牙骨质变厚。直到第60天，几乎没有受体组织细胞浸润的迹象。脾脏似乎是牙胚移植的合适部位。
