The document discusses the role of cephalometrics in planning distraction procedures. It states that cephalometry is a useful tool for treatment planning when used properly, noting considerations like the size, placement and orientation of distraction. It outlines how to determine the amount of distraction needed, including using customized norms and ratios for individuals rather than population averages. Placement and orientation of the jaws must also be considered along with soft tissue thickness to estimate hard tissue changes.