The Fixed Porter Appliance is designed to allow for a differential amount of expansion in the molar and cuspid/bicuspid region of a constricted maxillary arch. Lateral pressure is placed on the banded molars by adjusting the loop with the flat side of #139 pliers. The primary molars, bicuspids and cuspids can be adjusted independently by adjusting the lingual arms. Since it is typically easier to adjust an appliance out of the mouth, sliding vertical or horizontal brackets (as shown) can be fitted on the lingual aspect of the molar bands -- to facilitate removal of the wire without disturbing the banded teeth.