A base member for an orthodontic implant device. The base member makes it possible to easily and reliably attach a correction implement. The base member is secured by a plurality of screws that are embedded in a bone inside an oral cavity. Each of the plurality of screws has a screw part that is embedded in the bone and a polygonal-columnar head part that is exposed inside the oral cavity. The base member has at least three engagement holes that are provided so as to be capable of engaging the polygonal-columnar head parts and such that the centers thereof are not on the same straight line.