A replaceable head (10) for an electrically operated toothbrush comprising an elongated sleeve (11) having a connection (12) at a longitudinal end to engage with a connector (32) on a handle of a brush (30) of electric teeth, the sleeve (11) having a mount (13) for a bristle support at the opposite longitudinal end and having a bristle support (15) mounted on it to perform a rotational movement about an axis of rotation transverse to the longitudinal direction of the sleeve, with a shaft motor (18) of the head that extends longitudinally along the sleeve (11) and mounted to perform a rotational movement around a rotation axis generally aligned with the longitudinal direction of the sleeve, in the that: the sleeve (11) incorporates a flexible region (19) that allows the part of the sleeve (11) between the bristle support mount (13) and the flexible region (19) to move relative Ion to the connection (12) under pressure on the bristle support (15) during use, adjacent to the shaft end (18) of the spindle motor furthest longitudinally from the connection (12) is a spherical support part (12) of the spindle motor shaft, and the sleeve (11) has a corresponding receiving cavity (22) for the support piece of the spindle motor shaft that receives the spherical part (21) of the spindle motor shaft support, the spindle (10 ) incorporates a transmission system to convert the rotation of the spindle motor (18) into the rotation of the bristle support (15) around an axis of rotation transverse to the longitudinal direction of the shaft comprising an eccentric pivot (23) that extends from the shaft (18) spindle motor adjacent to the end of the shaft (18) spindle motor longitudinally further from the connection (12) to one end (24) of the shaft spaced shaft (18) spindle motor in a directed n radial with respect to the axis of rotation of the shaft (18) motor of the head, and having a spherical pivot support piece adjacent to the end (24) of the pivot, the bristle support (15) havin
