Preoperative planning. A. Variable densities of the resorbed bone are illustrated in different colors based upon CT. B. The measurements of the expected bone defect after removal of all regions (1, 2 and 3) giving an area of 90 × 110 mm which is the size of the designed implant synthetic bone flap. C. The expected final design of the bone flap replacing the defect and preserving the same skull contour.