Abstract: It has been found that the upper and lower dentures of false teeth tend to remain more securely in place if the marginal edges of the outer flange, in the case of the upper denture, and the inner flange, in the case of the lower denture, are thickened in the posterior areas of the respective plate. In the case of the upper denture, the marginal edge of the upper flange is curved sharply outwardly so as to engage the cheek of the wearer, during use, in the vicinity of the junction of the cheek with upper gum. This thickened marginal portion of the flange is greater in the posterior areas than in the anterior area of the plate. In the case of the lower plate, the posterior ends of the inner flange rearwardly from the second molars, are provided with inwardly and downwardly extending projections which, during use, extend beneath opposite sides of a person's tongue adjacent the rear thereof, and into engagement with the floor of the person's mouth.