Invisalign is a removable appliance that fits the teeth more intimately than other appliances. This characteristic is critical for the teeth to move in a controlled fashion. Movement of teeth with wire and bracket systems is mostly understood in two-dimensions. This presentation will focus on how to manipulate the Invisalign aligner in three-dimensions. Physics of the appliance will be explained based on laboratory studies, as well as, case-based presentations. Similarities and differences between the Invisalign aligner and wire and bracket appliance performance will be discussed. Teeth don't know what is pushing them, they just move; the clinician needs to know how to push.