胎儿筛骨的形态学研究

本文从组织学角度,研究胎儿筛骨的形态学变化以及水平板、纸板和筛凹的发育特点。结果表明:筛骨整体(在冠状位)呈等腰梯形,即纸板为梯形的两边;胎儿期的纸板在水平切面上呈向外凹的骨板,至出生时呈轻微的“S”形弯曲;胚胎第24周后,水平板的外侧部分逐渐形成筛凹,并随筛窦的气化而变薄,形成筛窦的顶部。上述结果提示:出生时其眶内侧壁(主要为纸板)结构不呈矢状平面,且与水平板间的角度(斜度)随胎龄增长而增大(P<0.01);筛骨水平板则由内侧部分的筛板和外侧部分的筛凹组成。

MORPHOLOGICAL STUDY OF THE ETHMOID BONE IN FETUS

Morphological changes of the ethmoid bone and dewelopmental features of horizpntal plate, lamina papyracea and ethmoidal fovea were studied histologically. The result showed that the whole ethmoid done (at frontal section) was isosceles trapezoid in shape, i e.the bilateral edges of the trapczoid were the lamina papyracea. In the human embryo, the lamina papyracea showed convex outward at horizontal section and showed slight "S" curvature at birth. In embryo after 24 weeks, the lateral portion of the horizontal plata changed gradually into ethmoidal fovea which became thinner with the peumatiztion of the cells and formed the roof of the ethmoid cells.These results imply that the medialwall of the orbit(mainly lamina papyracea)at birth was not in a sagital plane and the oblique angle between the lamina papyracea and the horizoptal plate was gradually increased with the age of embryo(P<0.01), and that horizontal plate was comprised of a medial portion, the cribriform plate, and lateral portion, the ethmoidal fovea.