A treatment partial can be designed to incorporate a spring or an expansion screw to upright or distalize a tooth. This design is especially useful on adult patients with 12-year molars that are tipped mesially. Retention and anchorage are accomplished by using two or more clasps and by having excellent tissue adaptation. Removable expansion appliances can often be adjusted between visits by the patient. Simply instruct your patient to activate the screw mechanism in the direction of the arrow, one turn per week. This provides 1mm of movement per month.