The mouthpiece includes a mouthpiece carrier member (14) having upper and lower sections which are adapted to receive the upper and lower teeth of a user. The mouthpiece carrier member has several embodiments which include side members and an intermediate member or members connecting the two side members to define the two sections. A bristle field (20) is mounted on the mouthpiece carrier member for contact with the surfaces of the teeth. The mouthpiece carrier member is moved in such a manner to produce a bristle action which has a significant axial component, resulting in the bristle tufts moving toward the teeth, contacting the teeth and moving away from the teeth, producing cleaning action on the teeth.
