Abstract
Fine structure of the epithelial remnants in the gubernacular canal of a crab-eating monkey at the primary occlusion stage was examined by light and transmission electron microscopy.
The epithelial remnants of the dental lamina from successional touth germs were seen throughout the gubernacular canal and up to the gubernacular foramen. The epithelial cells were surrounded by a basal lamina and were joined to one another by poor desmosomes. The cell membrane had hemidesmosomes that were seen along the basal lamina, and microvilli that interdigitated with those of the adjacent cells. The tonofilaments surrounded the nucleus, and some of them were joined to the desmosome and hemidesmosomes. This fine structure of the epithelial stands was similar to the epithelial remnant of Malassez. The epithelial cells near the tooth germ had numerous ribosomes and mitochondria. The rough-surfaced endoplasmic reticulum was not developed. In most parts of the sections examined, only a small number of atrophied epithelial cells was observed. However, among the epithelial cells near the gingival mucosa, we observed cells containing swollen mitochondria, dilated rough endoplasmic reticulum, and condensed tonofilaments, abnormalities which probably occurred due to the degeneration of the cells. There was a difference in fine structure between the two areas. Cellular debris apparently derived from the epithelial cells was observed within the extracellular spaces of the connective tissue. On the other hand, hemidesmosomes did not appear to be affected by the degeneration.
The presence of these highly specific intracellular and extracellular components suggests the existence of some specific activity that probably includes the maintenance of the bony canal.
