On the measurement of cranial thickness at nasion on cephalographs

Cranial bone thickness at nasion is difficult to measure by the conventional method of drawing a line at right angles to the tangent at nasion on the outer table. The difficulty arises from a lack of uniformity of the arc in this region. The proposed use of a constructed line, drawn at 30 degrees to the anterior projection of the Frankfort horizontal plane, provides an accurate, easily reproducible, and compatible alternative method of measurement.