Overlay dentures which are accepted as superposition appliances have been presented by three cases in this article. These kind of dentures are dedicated as prosthodontic restorations which are applied to extend maxillary arch horizontally in the cases of maxillary collapse. These restorations also increase the vertical dimension which has been lost and so help to improve the facial contour as well as esthetics of the individual-these dentures classified as removable partial or complete overlay dentures are generally applied in the cases of bilateral or unilateral maxillary collapse which have been caused by trauma or tumor resection.