Electron microscopy of normal auman gingival epithelium

Abstract

Biopsies of the labial part of normal gingival epithelium were obtained from 18 females (average age of 25 years) who had performed strict oral hygiene for two weeks or more. Standardized areas of the specimens were investigated electron microscopically. All specimens exhibited parakeratosis and were free from inflammatory cells. The optical basement membrane corresponded. to the basement lamina and an intermediate layer about 0.5 to 1 micron wide, containin various fibrils at random orientation. Cell junctions in each of the epithelial layers were typical desmosomes and maculae or zonulae occludentes. The intercellular space was interpreted to be closed from outside at the epithelial surface, subdivided into numerous compartments within all epithelial strata and open against the basement lamina. Glycogen was occasionally found in cells of the upper stratum spinosum and stratum granulosum only. The transition of cells into the stratum corneum was either abrupt or more gradual. Superficial to the stratum corneum, single or several cells of considerably less density were frequently observed. Melanocytes and Langerhans cells occurred interspersed between basal and spinous cells. The ultrastructural details are discussed with reference to the existing knowledge of other squamous epithelia.