Quantitative light and electron microscopical studies of the epithelial-connective tissue junction in intraoral mucosae.

The present study was designed to clarify the morphological nature of epithelial-connective tissue attachment by quantitative comparison of palatal and buccal mucosae. Tissue samples were obtained from ferrets and, following a strict sampling regime, sections were obtained for quantitative light and electron microscopy. Electron micrographs from the epithelial-connective tissue junction were subjected to analysis by serological intersection counting. Quantitative results show that palatal epithelium has a comparatively convoluted interface, and is twice as thick as buccal epithelium. Stereological data are presented for relative surface area of basal plasma membrane occupied by hemidesmosomes, mean hemidesmosomal diameter and numerical density of hemidesmosomes per unit area of basal plasma membrane. Larger hemidesmosomes are found in the palatal epithelium. Results suggest that a prominent rete-ridge pattern, as seen in the palatal epithelium, along with a greater specialized surface for adhesion, may be responsible for providing epithelial-connective tissue stability in regions subjected to high mechanical stress.