The histology of the muco‐gingival junction

Nineteen pieces of muco‐gingival tissue from man and monkey were examined by histological and histochemical methods. Neither a surface groove nor a change from keratinisation to non‐keratinisation were consistently seen in all specimens; the differing elastic tissue content of the gingiva and alveolar mucosa was therefore used to define the muco‐gingival junction. The surface groove, the keratinisation pattern, the distribution of hydrolytic enzymes and the glycogen content have been related to this junction. The gingiva and alveolar mucosa meet without a gradual transition zone suggesting that an intrinsic difference exists between them. This junction provides a useful model system for the examination of epithelial‐connective tissue interrelationships.