Small diameter wires are not threaded and therefore are subject to micromotion. When four or more smooth wires are used with good divergency, stability is adequate. When wire number is reduced or divergency is not adequate, surgeons choose to place stopper wires (also called olive wires) to reduce micromotion and enhance stability. Stopper wires have a centrally located expanded bead designed for placement against the bone. Most situations where hybrid frames are chosen will benefit from the added stability provided by stopper wires.