Brudvik P, Rygh P
Department of Orthodontics and Facial Orthopedics, Faculty of Dentistry, University of Bergen, Norway.
Eur J Orthod. 1994 Aug;16(4):265-73. doi: 10.1093/ejo/16.4.265.
Recent studies revealed that the initial root resorption occurred in the peripheries of the necrotic periodontal ligament (PDL) and was performed by mono-nucleated non-clast macrophage- and fibroblast-like cells (Brudvik and Rygh, 1993a, b). The aim of the present transmission electron microscopic (TEM) investigation was to study in more detail the cells involved in removal of the main hyalinized tissue and those involved in root resorption, occurring on the root surface situated beneath the main hyalinized tissue. Twelve male Wistar rats were used. The maxillary first molar was moved mesially by a fixed orthodontic appliance for 7 and 10 days. The results indicate that multi-nucleated giant cells (MNGC) without a ruffled border surface, as well as mono-nucleated macrophage-like cells were responsible for removal of the necrotic tissue and also for resorption of the surface parts of the root cementum. Although the present MNGC showed many morphological traits similar to the observed odontoclasts and osteoclasts, except for their lack of ruffled borders, it is assumed that they are derived from the mono-nucleated phagocytic system. Multi-nucleated clast-like cells with ruffled border were never observed near the remnants of the necrotic tissue. Such cells were found only in the resorption lacunae on root and bone surfaces.
最近的研究表明，最初的牙根吸收发生在坏死牙周膜（PDL）的周边，由单核非破骨巨噬细胞和成纤维细胞样细胞进行（Brudvik和Rygh，1993a，b）。本透射电子显微镜（TEM）研究的目的是更详细地研究参与清除主要透明样组织的细胞以及参与牙根吸收的细胞，这些吸收发生在主要透明样组织下方的牙根表面。使用了12只雄性Wistar大鼠。通过固定正畸矫治器将上颌第一磨牙向近中移动7天和10天。结果表明，没有皱褶缘表面的多核巨细胞（MNGC）以及单核巨噬细胞样细胞负责清除坏死组织以及牙根牙骨质表面部分的吸收。尽管目前的MNGC表现出许多与观察到的破牙细胞和破骨细胞相似的形态特征，但除了它们缺乏皱褶缘外，推测它们源自单核吞噬系统。在坏死组织残余物附近从未观察到有皱褶缘的多核破骨样细胞。此类细胞仅在牙根和骨表面的吸收陷窝中发现。
