Drill assistance device, screw guide device, and orthodontic tool installation-assisting device set

An aspect of the present invention is a drill assistance device comprising: a drill guide device that serves as a guide when forming a plurality of holes from a curved surface of a hard palate having the curved surface; and a guide sleeve that is fitted in the drill guide device in an attachable and detachable manner. With this device, it is possible to easily and accurately perform the hole making with a drill and the implant of a screw in an oral cavity. The drill guide device comprises: a guide frame unit that is formed by connecting a plurality of tubular guide frames to each other; a fixing member to be capped on a tooth of a patient; a connecting portion that connects the guide frame unit and the fixing member and determines arrangement of the guide frame unit on the curved surface; and at least one protruding portion that holds the guide sleeve inserted in any of holes inside the guide frames. The guide sleeve comprises: a tubular sleeve main body having an inner diameter that allows the drill to be inserted and an outer diameter that allows the sleeve main body to be inserted in any of the guide frames; a water injection slit that is provided in the sleeve main body; and projecting portions that are each fitted in at least one recessed portion provided in the at least one protruding portion when the sleeve main body is inserted in any of the holes of the guide frames.