In one embodiment, the invention can be an electric toothbrush including a trajectory detecting module configured to detect a trajectory of movement of a brush, the trajectory including a plurality of positions； an attitude detecting module configured to detect an attitude of the brush； a site estimating module configured to estimate a brushing site for each of the plurality of positions of the trajectory, each estimated brushing site being based on the trajectory detected by the trajectory detecting module； and a back most tooth detecting module configured to detect a back most tooth based on a change of the attitude detected by the attitude detecting module； wherein the site estimating module is further configured to correct the estimated brushing site for each of the plurality of positions of the trajectory based on the estimated site of the detected back most tooth
