An morphological study of qubernacular foramen (macroscopically, light microscopically and electron microscopically observation)

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1.Dry skulls of crab-eating monkey were classified by Hellman's dental age, and aging change of location and size of qubernacular foramen were observed.(1) Gubernacular foramen size of crab-eating monkey : AtICstage, lower canine was the smallest (mean : 0.36mm^2), and upper central incisorwas the largest (mean : 0.58mm^2). AtIIIAstage, upper canine was the smallest (mean : 0.58mm^2), and upper central incisor was the largest (mean : 1.67mm^2).(2) Monkey's upper canine size showed less aging change, on the other hand, upper central incisor showed remarkable change.2.Fine structure of the epithelial remnants in the gubernacular canal of a 3-month-old crab-eating monkey was examined by means of transmission electron microscopy to clarify the structure and function of the remnants. The following results were obtained :The gubernacular canal was filled with connective tissue, and strands of epithelial cells were located at the center of the canal. The fine structure of the epithelial atrands was simillar to epithelial remnant of Mallassez : The epthelial cells were surrounded by a basal lamina and joined to one another by desmosomes. In most parts of the section examined, only a small number of atrophied epithelial cells were observed : However, in the epithelial cells near the gingival mucosa, we observed cells containing swollen mitochondria, dilated rough endoplasmic reticurum, and condenced tonofilaments, which abnormalities probably occurred due to the degeneration of the cells. Cellular debris apparently derived from the epithelial cells was observed within the extracellular spaces of the connective tissue. Onthe other hand, hemidesmosomes did not appear to be affected by the degeneration.The presence of these highly specific intracellular and extracellular components suggested the existence of some speciffic activity that probably includes the maintenance of the bony canal.