目的:比较胎儿和成人眶肌(OM)的形态,并描述成人的详细地形解剖。
方法:使用来自15个近期胎儿和21个老年尸体的单侧轨道,以20-100µm的间隔制备半材料水平或矢状石蜡切片。除了常规组织学,我们对平滑肌肌动蛋白进行了免疫组织化学。
结果:近期,OM始终从the骨或蝶骨的大翼广泛延伸到上颌骨或筛骨。因此,这是一个覆盖未来下轨道裂缝的大薄片。相比之下,成年OM是一个薄且小的肌肉束,连接(1)蝶骨的大翼与上颌骨(11/19尸体),(2)蝶骨的小翼至上颌骨(5/19)或年夜翼(3/19)。较小的OM可能会限制在较大的机翼(5/19尸体)或上颌骨(3/19)内。这五种OM中的两种共存于八个轨道中。在胎儿中没有看到OM附着在小翼上,而成人不存在筛骨附着。
结论:出生后似乎建立了OM的小翼附着。三个直肠的共同起源越来越多,很可能参与了“窃取”筛骨的近期OM依恋。老年人残余样OM的强免疫反应性表明,OM收缩仍然可能发生,以抵抗通过细静脉的流量增加。然而,收缩可能没有临床意义。
OBJECTIVE: To compare fetal and adult morphologies of the orbital muscle (OM) and to describe the detailed topographical anatomy in adults.
METHODS: Using unilateral orbits from 15 near-term fetuses and 21 elderly cadavers, semiserial horizontal or sagittal paraffin sections were prepared at intervals of 20-100 µm. In addition to routine histology, we performed immunohistochemistry for smooth muscle actin.
RESULTS: At near term, the OM consistently extended widely from the zygomatic bone or the greater wing of the sphenoid to the maxilla or ethmoid. Thus, it was a large sheet covering the future inferior orbital fissure. In contrast, the adult OM was a thin and small muscle bundle connecting (1) the greater wing of the sphenoid to the maxilla (11/19 cadavers), (2) the lesser wing of the sphenoid to the maxilla (5/19) or the greater wing (3/19). The small OM was likely to be restricted within the greater wing (5/19 cadavers) or the maxilla (3/19). Two of these five types of OM coexisted in eight orbits. OM attachment to the lesser wing was not seen in fetuses, whereas ethmoid attachment was absent in adults.
CONCLUSIONS: The lesser wing attachment of the OM seemed to establish after birth. A growing common origin of the three recti was likely involved in \"stealing\" the near-term OM attachment from the ethmoid. The strong immunoreactivity of remnant-like OM in the elderly suggests that OM contraction is still likely to occur against the increased flow through a thin vein. However, the contraction might have no clinical significance.