A tool for obtaining a dental occlusion in an edentulous patient, characterized in that there are provided: a main body including a single rear curved plate, having a first surface that includes a first intermediate part along a vertical direction, to be positioned at an intraoral buccal of maxillary and mandibular ridges of the edentulous patient, a single front curved plate, having a surface that includes a second intermediate part along the vertical direction to be positioned at extraoral upper and lower lips of the edentulous patient, a connecting part that connects the first intermediate part of the rear curved plate and the second intermediate part of the front curved plate, and a through-hole that penetrates the rear curved plate, the connecting part, and the front curved plate, wherein a position of the main body is fixed in a state in which the connecting part is held between the upper and lower lips; and an adjusting shaft inserted into the through-hole of the main body, and having a first end projecting extraorally from a center between the upper and lower lips, and a second end which has a tongue support intraorally holding a tip end of a tongue, wherein the rear curved plate has a second surface opposite to the first surface, and the through-hole penetrates the rear curved plate from the second surface to the first surface of the rear curved plate, and wherein a position of the tongue support is adjustable by the adjusting shaft when obtaining the dental occlusion in the state in which the connecting part is held between the upper and lower lips and an impression material is applied on the intraoral side on the second surface of the rear curved plate. a main body including a single rear curved plate, having a first surface that includes a first intermediate part along a vertical direction, to be positioned at an intraoral buccal of maxillary and mandibular ridges of the edentulous patient, a single front curved plate, having a surface that includes a second intermediate part along the vertical direction to be positioned at extraoral upper and lower lips of the edentulous patient, a connecting part that connects the first intermediate part of the rear curved plate and the second intermediate part of the front curved plate, and a through-hole that penetrates the rear curved plate, the connecting part, and the front curved plate, wherein a position of the main body is fixed in a state in which the connecting part is held between the upper and lower lips; and an adjusting shaft inserted into the through-hole of the main body, and having a first end projecting extraorally from a center between the upper and lower lips, and a second end which has a tongue support intraorally holding a tip end of a tongue, wherein the rear curved plate has a second surface opposite to the first surface, and the through-hole penetrates the rear curved plate from the second surface to the first surface of the rear curved plate, and wherein a position of the tongue support is adjustable by the adjusting shaft when obtaining the dental occlusion in the state in which the connecting part is held between the upper and lower lips and an impression material is applied on the intraoral side on the second surface of the rear curved plate.