Abstract: Dental impression trays, full, quadrant and anterior, shaped to closely conform to either the maxillary or mandibular ridges for either dentulous or edentulous cases have sections which anatomically approximate surrounding tissue areas with peripheral border relief for muscle attachments and contiguous tissue areas. The trays are formed of an acrylic having a glass transition temperature slightly above body temperature so that they may be heated above their softening temperature exteriorly of the oral cavity, positioned over the oral area of which an impression is to be made, and then manually molded to approximate intimate conformity to the desired oral structures before they harden. A pleat formed in the central vault of a maxillary tray accommodates transverse adjustment. When the tray cools and hardens it is removed, allowing a custom final impression to be thus formed in a single procedure.