US Patent 9332828 Brush head for an electric toothbrush

A brush head for an electric toothbrush having a support structure rotatably oscillated by a motor in the handle of the toothbrush. A plurality of bristle tufts are mounted on the support structure in three ring-like series concentrically about a center point of the support structure. The bristle tufts are arranged in a unique arrangement whereby no more than two of the bristle tufts in the intermediate series and innermost series lie on a diameter line passing through the center point. The outermost and intermediate series of bristle tufts may be arranged in oval-shaped rings and the bristle tufts of the inner series may have a circular arrangement. All of the tufts preferably have the same height and diameter.