Formation of Periodontal Tissues around Subcutaneously Transplanted Hamster Molars
Formation of Periodontal Tissues around Subcutaneously Transplanted Hamster Molars
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皮下移植仓鼠磨牙周围牙周组织的形成
DOI：
10.1177/00220345600390040501
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发表时间：
1960
影响因子：
7.6
通讯作者：
R. Hoffman
中科院分区：
文献类型：
--
作者：
R. Hoffman
本研究的目的是确定发育中的牙齿是否对其周围组织有形成性影响，如果有，这种影响会延伸多远，持续多长时间。离体显微解剖研究表明，发育中牙齿的釉质器官对牙乳头内的间充质产生各种影响。它的分裂被认为影响了间充质最初的凝聚形成牙乳头，成牙本质细胞的分化，以及牙冠和牙根的一般形状。然而，釉质器官也可能对牙囊周围间充质产生影响的可能性还没有实验证实。牙囊向由牙周膜和牙槽骨组成的永久性牙周组织的转化与牙根的生长发育同时进行。提示牙周组织发育与牙体发育之间存在某种协调作用。为了检测这种影响是否存在，在牙根形成之前，将发育中的仓鼠磨牙的成釉器和牙乳头从它们的牙囊中分离出来，移植到通常不形成牙周组织的结缔组织中，并使其发育。结果发现，在宿主体内4周后恢复的所有健康标本周围都有组织化的牙周组织，这表明存在着来自发育中的牙根的组织化影响。影响的程度被发现局限于牙周膜和牙根周围相对较薄的牙槽骨和牙根之间的骨。形成骨周围移植的细胞必须由宿主提供。宿主细胞向成骨细胞转化的刺激可能来自釉器官及其衍生物--Hertwig上皮根鞘。这种刺激被发现，
Thepurpose ofthepresent investigation istodetermine whether thedeveloping tooth hasaformative influence uponthetissues whichsurround itand,ifso,howfarthe influence extends andhowlongitlasts. Invitro microdissection studies haveindicated thattheenamel organofthedeveloping tooth exerts avariety ofinfluences inwardly uponthemesenchyme within itthedental papilla. Itsepithelium isbelieved toinfluencetheinitial condensation ofmesenchyme toformthedental papilla, thedifferentiationofodontoblasts, andthegeneral shaping ofthetooth crownandroots. However, thepossibility thattheenamel organmightalsoexert influence outwardly uponthe surrounding mesenchyme ofthedental sachasnotbeenexperimentally tested. The transformation ofthedental sacintothedefinitive periodontium, consisting ofthe periodontal ligament andalveolar bone, proceeds simultaneously withthegrowth and development oftheroots. Thissuggests somekindofco-ordinating influence between periodontium development andthedevelopment ofthetooth proper. Inorder totest whether suchaninfluence exists, theenamel organ anddental papilla ofthedeveloping hamster molar weredissected fromtheir dental sacbefore rootformation, transplanted intoconnective tissue whichordinarily doesnotformperiodontium, andallowed to develop. Itwasfoundthatallhealthy specimens recovered after 4weeksinthehost hadorganized periodontium around themselves; this suggests theexistence ofanorganizing influence emanating fromthedeveloping root. Theextent oftheinfluence wasfoundtobelimited totheperiodontal ligament anda relatively thinshell of alveolar bonearound theroots andboneinthespace between theroots. Cells forming bonearound transplants seemtohavebeensupplied bythehost. The stimulus forconversion ofhostcells intoosteoblasts probably camefromtheenamel organanditsderivative-Hertwig's epithelial rootsheath. Thisstimulus wasfound to