The architecture of human gingival reticulin

Abstract

The anatomy of the reticulin fibrils in the gingival connective tissue has been examined histologically in silver impregnated cold microtome sections and paraffin sections of healthy, oedematous and chronically inflamed gingival connective tissue. The reticulin network consists of three groups of fibrils which are continuous with one another. These are the interfibrillar reticulin, the subepithelial reticulin and the reticulin in the walls of the blood vessels. The interfibrillar reticulin is arranged in a definite pattern. Some of these fibrils, termed longitudinal fibrils, pursue a straight or curved course which is related to the long axes of the associated collagen fibres. Some of the branches from these fibrils follow a similar course while others, termed circumferential fibrils, run more or less at right angles to the long axes of the collagen fibres. It is postulated that there is a unit fibril of collagen, the diameter of which is undetermined, which is ensheathed in a network of interfibrillar reticulin. The reticulin fibrils surrounding adjacent collagen fibrils are continuous with one another. The ensheathed collagen fibrils are grouped side by side to form units of larger diameter, which in their turn are surrounded by reticulin fibrils continuous with, but thicker than those surrounding the unit fibrils. The larger the collagen unit surrounded, the thicker are the reticulin fibrils. The fibres and fibrils of the subepithelial reticulin are arranged in patterns similar to those of the interfibrillar reticulin but are thicker. These fibres and fibrils constitute the enlarged fibrils of the interfibrillar network which ramifies over most of the superficial surface of the collagen fibres. Their arrangement is dependent on the relationship of these collagen fibres to the connective tissue-epithelium junction.