Toothbrush

A toothbrush comprising:

• a head portion provided on a tip end side in a long axis direction and having a bristle tufting surface;
• a grip portion disposed on a rear end side from the head portion;
• and
• a neck portion disposed between the bristle tufting surface and the grip portion,
• wherein a sensing portion for sensing that an external force in a first direction orthogonal to the bristle tufting surface exceeds a threshold value is provided on a rear end side from the bristle tufting surface,
• the sensing portion includes
• a reversal portion that connects a first region on the tip end side from the sensing portion and a second region on the rear end side from the sensing portion, and that snaps, buckles, and reverses as the head portion is displaced on a rear surface side opposite to the bristle tufting surface in the first direction due to the external force exceeding the threshold value, and
• an elastic deformation portion that is disposed with a gap from the reversal portion, 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, and
• the reversal portion is located between an outer contour on the bristle tufting surface side and an outer contour on the rear surface side of the elastic deformation portion in a side view viewed in a direction orthogonal to the long axis direction and the first direction.