Figure 8: Illustration demonstrating the two possibilities of reducing side effects in situations in which a greater unilateral gain is needed in the Class II correction: Elastic association with the same direction but reduced force on the opposite side (A), and the association of vertical elastics in the canine region, with greater force on the left side, where there is no need for AP correction (B). In the first situation, there is still a greater tendency to extrusion on the right side of the upper arch, as shown by the arrows in red. In the second situation, the extrusive force is similar on both sides of the upper arch; however, there is a greater extrusive force on the left side of the lower arch. To minimize the effects on the lower arch, thicker rectangular archwires can be used.