The elastic system fibres in healthy human gingiva.

In human gingiva, the elastic system fibres, namely oxytalan, elaunin and elastic fibres, are distributed in the upper, medium and deep layers of gingival connective tissue, respectively. They are formed by a microfibrillar and an amorphous component characterized as elastin. In the gingival connective tissue fibroblastic cells are likely to be the main source of production of elastin in the extracellular matrix. Elastin is secreted as a soluble precursor (tropoelastin), which spontaneously forms insoluble aggregates of elastin. Elastin is then laid down at the surface of the microfibrillar component, which could serve as a site for deposition of elastin during elastogenesis, and subsequently be incorporated in an amorphous area to form elaunin and elastic fibres.