Abstract: A butterfly attachment to guide a clear aligner to grip a tooth. The butterfly attachment is formed by two substantially quarter sphere units, wherein each unit has a convex surface and a concave surface. The two units are merged at their convex edge mid portions, such that the convex surfaces are continuous and forms a front face resembling a valley shape. The rear face of the butterfly attachment formed by the concave surfaces is also continuous and concave that corresponds to contours of the tooth.