In previous animal studies, we have demonstrated that an increase in orthodontic force magnitude is accompanied by higher levels of cytokine and chemokine expression only up to a certain point, leading us to proposed that there is a “biological saturation point” after which the magnitude of force will not increase the biological response nor the tooth movement. In this chapter we examine the effect of age on this response and show that saturation of biological response to orthodontic force exists in humans and that the saturation point varies among individuals. Adolescents reach a saturation point at a higher magnitude of force than adults, and therefore, lower magnitudes of orthodontic force should be utilized in adult patients. As time passes, all patients’ saturation points will increase, and they can tolerate higher force magnitudes.