Abstract: A toothbrush includes a head portion (10) having a bristle tufting surface; a grip portion (30) disposed on a rear end side from the head portion; a neck portion (20) disposed between the bristle tufting surface (11) and the grip portion; and a sensing portion (70) for sensing that an external force in a first direction orthogonal to the bristle tufting surface exceeds a threshold value. A reversal portion (80) connects a first region and a second region, and snaps, buckles, and reverses as the head portion is displaced on a rear surface side due to the external force exceeding the threshold value. An elastic deformation portion (90) connects the first region and the second region, and elastically deforms at least up to the external force at which the reversal portion snaps, buckles, and reverses.

Abstract: A toothbrush includes a head portion (10) having a bristle tufting surface; a grip portion (30) disposed on a rear end side from the head portion; a neck portion (20) disposed between the bristle tufting surface (11) and the grip portion; and a sensing portion (70) for sensing that an external force in a first direction orthogonal to the bristle tufting surface exceeds a threshold value. A reversal portion (80) connects a first region and a second region, and snaps, buckles, and reverses as the head portion is displaced on a rear surface side due to the external force exceeding the threshold value. An elastic deformation portion (90) connects the first region and the second region, and elastically deforms at least up to the external force at which the reversal portion snaps, buckles, and reverses.

Abstract: A toothbrush includes a head portion (10) having a bristle tufting surface; a grip portion (30) disposed on a rear end side from the head portion; a neck portion (20) disposed between the bristle tufting surface (11) and the grip portion; and a sensing portion (70) for sensing that an external force in a first direction orthogonal to the bristle tufting surface exceeds a threshold value. A reversal portion (80) connects a first region and a second region, and snaps, buckles, and reverses as the head portion is displaced on a rear surface side due to the external force exceeding the threshold value. An elastic deformation portion (90) connects the first region and the second region, and elastically deforms at least up to the external force at which the reversal portion snaps, buckles, and reverses.