Abstract: Patients with ectodermal dysplasia or having undergone cleft surgery with anodontia or hypodontia, hypoplastic conical teeth and patients severely worn dentition is a difficult condition to treat because of the limited tooth structure remaining. These patients often exhibit loss of vertical dimension of occlusion and esthetic problems. Such patients often need complex prosthetic treatment. Financial constraints or other priorities often restrict one from choosing the most desirable treatment. The overlay removable denture is a prosthesis that covers and is partially supported by natural teeth, tooth roots, or dental implants forming an effective method of treating such patients. This first article, in this series of two articles, discusses alternative concepts of overdenture fabrication that could be used apart from the conventional tooth supported overdentures, their advantages, complications and success.