[Tissue induction and mucogingival surgery: a review of the literature].

Most of the investigations reviewed in the present paper show that the connective tissue has an inductive potential upon epithelial differentiation. As for the investigations showing an epithelial predetermination, one must admit that they have been limited to particular tissue systems (for instance feathers and hairs) and that they could imply errors of manipulation or interpretation. As stated by Gilette: "Mesenchyme as the determinant is the favorite today, but perhaps only because experiments to demonstrate the opposite would be harder to assess" (Gilette, 1971). On the clinical point of view, one could draw an important conclusion from these investigations: at the present time, only the free or pedicle mucosal grafts including epithelium and connective tissue, or only connective tissue, are indicated to obtain a satisfactory increase of the width of attached gingiva.