A root canal treatment information apparatus includes circuitry which stores three-dimensional information including information on a root canal of teeth in a storage, the three-dimensional information being acquired by an X-ray CT image capturing device, specify a tooth as a target of interest, generate a tooth image of the tooth, instruct display of the tooth image on a display, generate, based on the three-dimensional information, a root canal extension direction image showing a root canal extension direction along the root canal of the tooth, and instruct display of the root canal extension direction image on the display as overlapping, and in correspondence with, the tooth image.
