(17) a working edge design that does not sufficiently penetrate the tongue papillae; (18) a handle that does not fit within standard toothbrush holders; (19) a working edge or other surface that is hazardous and/or threatening due to sharp edges; (20) a design too flimsy resulting in a lack of control during use; (21) a size, shape, and design that is too short thereby increasing the risk of accid