Abstract: The invention relates to a mechanical toothbrush with a dual rotary brushing system having a handle and a head fixed on the handle. The head is provided with adjacent contrarotating brushes that are of cylindrical shape and have substantially parallel axes, each of them being supported at least at their distal end by a bearing and each being driven by a shaft. The shafts are flexible and supported by the two bearings to allow the two brushes to move away from and towards each other. The support includes four flexible branches around a central component serving to fix the support on the head composed of a single arm. The support and/or the head of the toothbrush are designed such that the support is fixed on the head while allowing the support to pivot about its point of fixation to the head.