Application of stereologic methods to stratified gingival epithelia*

Abstract

SUMMARY Stereologic point‐counting procedures were applied to estimate quantitative tissue and cytoplasm parameters of the oral and the junctional epithelium of the human gingiva. Three gingival biopsies of female children, obtained and processed under standardized conditions, served (1) to determine the minimal sample size of cytoplasmic area required for estimating representative volumetric parameters in different strata of both epithelia, and (2) to compare average volume and surface density data derived from standardized samples in epithelial cross sections cut at two planes orientated perpendicular to each other. Sampling of electron micrographs, performed at two levels of magnifications according to a systematic stratified random sampling procedure consisted of recording field strips parallel to the epithelial or tooth surface within each of the various strata. The optimal sample size required varied for different organelles and epithelial strata. Minimal sample size of cytoplasmic area per biopsy were 300–440 μm2 for basal, and 450 μm2 for stratum spinosum cells of oral epithelium, and 130–185 μm2 for basal cells of the junctional epithelium. Average morphometric parameters for gross tissue components (cells, nuclei, cytoplasm, intercellular space) which resulted from analysing 4900 μm2 tissue area in each of the epithelia in each biopsy, were almost identical when determined in two different section planes. Volume and surface density data of cytoplasmic organelles (mitochondria, rough and smooth endoplasmic reticulum, cytoplasmic filaments) resulting from a sample of 280 μm2 cytoplasmic area per stratum and biopsy, revealed differences of varying magnitude, when determined in the two section planes. These differences were markedly smaller than those between comparable strata of both epithelia. Discussion of sampling procedures concluded that the type of sampling used for the present study is suitable for comparative morphometric studies.

Variations in the nuclear‐cytoplasmic ratio during epithelial differentiation in experimental oral carcinogenesis

“…The principle of progtessive mean plots (Burn et al 1968, Schroeder & Munzel-Pedrazzoli 1970 was used to determine the minimum number of micrographs required to provide stable mean values for statistical comparisons. The sample used in this investigation provided a stable mean within the 5% (±2.5%) range.…”

A comparison of two sampling procedures for stereological analysis of cell pellets

“…If a morphometric analysis were to be done on equatorial profiles only, it would obviously introduce a definite sampling bias in favour of the nucleus, and possibly affect the recorded volumetric parameters of subcellular components polarized with respect to the nucleus. However, Schroeder & Miinzel-Pedrazzoli (1970) have recently demonstrated that a biased sampling procedure can produce acceptable morphometric information, at least in a structurally oriented tissue (gingival epithelium).…”

Quantitative electron microscopical analysis of leukocyte infiltration in oral ulcers of Behcet's syndrome

“…Indeed, these cells increase with the duration of the ulcer, as is also seen in recurrent oral ulcers (Graykowski et al, 1966;Lehner, 1969). The number of X-lymphocytes which resemble plasmablasts (Schroeder & Graf-de Beer, 1976) reached 2-2",, in one of the 3-day biopsies, suggesting that plasma cells might be generated at a later stage of ulceration. A moderate percentage of ncutrophils was found in the four biopsies and the proportion of these cells would have been greater if the central ulcerated zone had been examined.…”