Replacement head for electric toothbrush

A replacement head for an electromagnetic toothbrush drive includes a mechanical linkage assembly for converting linear drive motion into rotational movement of the brush head. The mechanical linkage assembly includes a fixed shaft and a lever arm that extend between a movable bottom member and a fixed top member, and a link member rotatably connected to the top member and the brush head. The lever arm pivots about a fulcrum formed in the top member, and engages the link member. When the bottom member oscillates as a results of the actuation of the electromagnet in the drive unit, the lever arm pivots about the fulcrum and drives the link member to rotate in an arc shaped pattern. The rotation of the link member consequently rotates the brush head.