A comparison of lower face changes.

A comparison has been made of cases treated with deliberate anchorage preparation (Class III elastic mechanics) prior to Class II elastic mechanics and cases treated with Class II elastic mechanics only. Treatment goals were the same. Extraoral traction was used as necessary to achieve those goals. Appliance quantity and size were the same. Age, sex, and severity of malocclusion were comparable. It remained that the anchorage-prepared cases demonstrated a flattening of the mandibular plane, greater retraction of the lower incisors, more retraction of midface, and more protraction of lower face. These changes of lower face are consistent with the normal growth changes of the human face.