Architecture and density of the connective tissue papillae of the human oral mucosa.

The papillary body of the human oral mucosa was studied at six different sites. Biopsy and autopsy material from 57 individuals, 11-81 years of age, was split chemically along the basal lamina and the epithelium-connective tissue interface examined by light and scanning electron microscopy. Morphometric techniques were employed in order to determine: epithelial thickness, height and density of connective tissue papillae and the percentage of basal epithelial surfaces occupied by them. In the majority of sites, connective tissue plateaux or ridges carrying a variable number of single or grouped papillae were found to be the basic structural units of the papillary body. Three regions with diferent characteristics of the epithelium-connective tissue interface could be identified: (1) floor of the mouth, (2) lip and cheek, (3) gingiva and hard palate. The floor of the mouth showed the lowest connective tissue papillae density, the smallest papillae, and connective tissue plateaux separated by narrow grooves. Lip and cheek mucosae revealed an intermediate density, the papillae were frequently bifurcated and angulated. Gingiva and hard palate were characterized by the highest papillary density and by papillae which were cylindrical, slender and erect. The alveolar mucosa exhibited intermediate features between those of the floor of the mouth and those of the cheek mucosa.