Mizuno I, Saburi N, Taguchi N, Kaneda T, Hoshino T
Department of Oral Surgery, Nagoya University School of Medicine.
Shika Kiso Igakkai Zasshi. 1990 Feb;32(1):69-79. doi: 10.2330/joralbiosci1965.32.69.
The ultrastructure of the articular fibrous zone of the rat mandibular condyle was observed at 3 and 6 weeks of age in order to investigate the histological changes that occur during the establishment of mastication after suckling. We divided the articular fibrous zone into two layers (F1 layer and F2 layer). The F1 layer was composed of fibroblast-like cells, macrophage-like cells, and the matrix which consisted of granular or fibrillar material, loosely arranged small bundles of collagen fibrils with uniform thickness of 30-50 nm, and independent microfibrils. The F1 layer was continuous with the synovial membrane without any distinct boundary in its peripheral area. Mitotic figures could infrequently be observed in the fibroblast-like cells. The cells in the F2 layer closely resembled fibroblasts. The matrix in the F2 layer mostly consisted of densely arranged bundles of collagen fibrils which are not of uniform diameter ranging 40-100 nm. Elastic fibers occurred among the collagen fibrils. The F1 layer which was observed clearly at 3 weeks almost disappeared at 6 weeks of age. It is confirmed that the F1 layer resembling the synovial membrane exists over the condyle up to the weaning period about 3 weeks of age but it degenerates before 6 weeks of age when the masticatory function is established.
为了研究大鼠在断奶后咀嚼功能建立过程中发生的组织学变化，我们观察了3周龄和6周龄大鼠下颌髁突关节纤维区的超微结构。我们将关节纤维区分成两层（F1层和F2层）。F1层由成纤维细胞样细胞、巨噬细胞样细胞以及基质组成，该基质由颗粒状或纤维状物质、厚度均匀为30 - 50纳米的松散排列的小束胶原纤维和独立的微纤维构成。F1层在其周边区域与滑膜连续，没有任何明显边界。在成纤维细胞样细胞中很少能观察到有丝分裂象。F2层中的细胞与成纤维细胞非常相似。F2层中的基质主要由密集排列的胶原纤维束组成，其直径不一，范围在40 - 100纳米。弹性纤维出现在胶原纤维束之间。在3周龄时清晰可见的F1层在6周龄时几乎消失。证实了类似滑膜的F1层在髁突上一直存在到约3周龄的断奶期，但在6周龄咀嚼功能建立之前就退化了。
