Abstract: A rotary electric toothbrush including a power handle having a foot and a motor having a rotatable power shaft. A brush stem is attached to the power handle and extends therefrom to terminate at a stem head. A brush cartridge is attached to the stem head and extends therefrom to terminate at a toothbrush head. The brush cartridge includes at least one generally cylindrical brush oriented approximately headward-to-footward. A drive shaft extends from the power handle to the brush. A transmission transmits the motion of the power shaft to selectively cause the drive shaft alternatively to rotate about its longitudinal axis and to move parallel thereto in a reciprocating manner. A user of the rotary electric toothbrush thus may direct power from a single motor selectively to cause the brush to rotate about its longitudinal axis and, alternatively, to move in a reciprocating manner parallel thereto.