Lower three-screw sagittal
In as much as the roots of molars are strongly anchored, the lower Sagittal is more efficient when a lip bumper is added. However, in order to obtain the best results during distalization of the first anterior molars, it is better to extract the second molars. If these teeth are not yet grown, it must be ensured that they are not impacted during treatment. Note that acrylic pads are seldom fitted on lower expansion appliances.