A scanning electron microscopic study of fissured tongue.

In this study, scanning electron microscopy was used to describe the surface morphology of fissured tongue. Tissue samples from the anterior part of the tongue were taken from 15 patients with fissured tongue. The formalin-fixed samples were processed routinely for scanning electron microscopy. Typically, the surface of a fissured tongue was covered with hairless papillae of various sizes. The biggest papillae were larger than the body of a normal filiform papilla, and the apex was rounded and rough. On the other hand, some of these papillae had a few hairs and resembled normal filiform papillae, but were flatter. In addition some papillae formed only slight elevations on the tongue mucosa, which was smooth and contained some desquamating cells. The walls of the fissure found in macroscopical examination consisted of very low elevations of the smooth mucosa with some desquamating cells. At high magnification the superficial cells of the epithelium were polygonal. On their surface there were branching or parallel microplicae, which were often broken. Only occasionally superficial cells of the large papillae had a pitted appearance. The knob-like structures found among the microplicae and small cracks between the epithelial cells are discussed from the standpoint of the pathogenesis of fissured tongue.