The way in which cells communicate with each other is fundamentally important for developing and maintaining normal tissue structure and function. In order to get a better understanding of cell adhesion, researchers have long been trying to identify and characterize chemical structures at the cell surface that might participate in, or mediate, cell-cell and cell-matrix adhesion. During the last decade, this has led to the identification of a number of cell-surface adhesion proteins and their ligands, which may be either proteins or carbohydrates. The LEC cell-adhesion molecule family is a group of cell-adhesion molecules with a lectinlike domain. They bind to carbohydrate structures, some of which have been identified on dendritic cells in oral epithelium. LEC cell-adhesion molecules are found on endothelial cells during inflammation and may, in such situations, be involved in the recruiting of dendritic and other inflammatory cells, thereby playing a role in the regulation of inflammatory reactions in the oral mucosa. The integrin family is another group of cell-surface adhesion molecules recently identified in oral mucosa that participate in cell-matrix and cell-cell adhesion in many important processes including wound healing, immunodefense mechanisms, and oncogenic transformation. Knowledge of the distribution of cell-adhesion molecules and their ligands and of the mechanism that controls their expression is, therefore, of great importance in understanding of the development of disease in the oral mucosa.