US Patent 7281289 Automatic pressure release toothbrush

A toothbrush operable by a user has a handle having a distal end, a head having a proximal end extending from said handle's distal end and bristles extending generally in a first direction designated “forward”. The head has a first orientation relative to the handle when the head is relaxed, the head being pivotable relative to said handle out of the first orientation to a second orientation rearward of the first orientation, when a force greater than a predetermined threshold level is applied to the head in a direction generally opposite the first direction. The head remains out of the first orientation until it is manually returned by the user to the first orientation.