The simplest form of orthodontic tooth movement is tipping because it involves the rotation of a tooth around its center of resistance, resulting in movement of the crown with minimal displacement of the root. This requires the least complex force system compared to bodily movement or intrusion, which need controlled forces acting uniformly on the entire root. Tipping is easier to achieve clinically as it demands lower force magnitude and simpler mechanics. Understanding this allows for efficient initial correction during orthodontic treatment.

Reference: Proffit, Contemporary Orthodontics, 6th Edition.