The morphology and distribution of Merkel cells in primate gingival mucosa.

The morphology and distribution of Merkel cells in primate gingival mucosa have been studied by correlated light and electron microscopic techniques. The gingival mucosa is composed of a stratified squamous epithelium with a dense underlying connective tissue stroma. The epithelium inter-digitates with the underlying connective tissue forming long interconnected rete ridges. Merkel cells and their associated axons are abundant in gingival mucosa where they are located, either individually or in clusters, at the base of epithelial rete ridges. These cells have an identical morphology to Merkel cells described by others in the hard palate, hairy skin, glabrous skin and eyelid. While individual Merkel cells are found throughout the gingival mucosa, Merkel cell clusters are most numerous in the mandibular lingual gingival mucosa. When correlating this finding with data from other investigators, it appears that Merkel cell clusters are located preferentially in the masticatory mucosa in intimate contact with the tongue and thus may function as an important source of somatosensory feedback providing valuable information regarding the position of the tongue in the oral cavity.