The eternal tooth germ is formed at the apical end of continuously growing teeth
The eternal tooth germ is formed at the apical end of continuously growing teeth
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DOI：
10.1016/j.archoralbio.2004.09.008
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发表时间：
2005-02-01
影响因子：
3
通讯作者：
Harada, H
中科院分区：
文献类型：
--
作者：
Ohshima, H;Nakasone, N;Harada, H
众所周知，啮齿动物的门牙是持续生长的牙齿，由根尖末端的细胞增殖和切缘的磨损维持。这种类型的牙齿有一种特殊的上皮结构，用于维持干细胞，显示出根尖末端的球状上皮突起。牙根尖端连续横切面上皮-间充质间隔向切面方向的形态转变可能反映了胎儿期牙胚的发育。根据目前的组织学和分子生物学研究，在人、小鼠和大鼠磨牙牙胚中，根尖末端的特殊结构与引起Hertwig上皮根鞘(HERS)的颈环明显不同。因此，我们提出了一个新的概念，即产生各种牙齿后代的永恒牙芽是在持续生长的牙齿的顶端形成的，并提出了一个新的术语“顶芽”来表示这种特殊的上皮结构。此外，BrdU标记分析表明，豚鼠磨牙是持续生长的牙齿，在根尖末端也有多个特定的增殖区和“顶芽”。(C)2004爱思唯尔有限公司。保留所有权利。
Rodent incisors are known to be continuously growing teeth that are maintained by both the cell-proliferation at the apical end and the attrition of the incisal edge. This type of tooth had a special epithelial structure for the maintenance of stem cells, showing the bulbous epithelial protrusion at the apical end. The morphological transition of the epithelial-mesenchymal compartment by serial transverse sections of the apical end toward the incisal direction is likely to reflect the development of the tooth germ in the prenatal stage. Based on the present histological and previous molecular biological studies, the special structure at the apical end is obviously different from the cervical loop giving rise to Hertwig's epithelial root sheath (HERS), in human, mouse and rat molar tooth germs. Hence, we propose a new concept that the eternal tooth bud producing various dental progeny is formed at the apical end of continuously growing teeth, and a new term "apical bud" for indicating this specialized epithelial structure. Furthermore, BrdU labelling analysis suggested that the guinea-pig molars, which were continuously growing teeth, also possessed plural specific proliferative regions and "apical bud" at the apical end. (c) 2004 Elsevier Ltd. All rights reserved.