Abstract: An electric rotary toothbrush is provided. The electric rotary toothbrush includes a housing with an electric motor located within the housing. The electric motor drives a power rod to provide a rotational force to a rotary brush head. The power rod is located in a shaft portion that extends from the housing. The first end of the shaft comprises a curved tubular neck portion that tapers to a curved edge portion. The second end of the shaft is removably mounted on the housing. A rotary brush head is rotatably mounted on the curved tubular neck portion of the first end of the shaft. The rotary brush head includes a ring and pinion gear assembly. The pinion gear is coupled to the power rod and drives the annular ring in an end over end motion. The annular ring has bristles extending radially from the periphery of the annular ring.