1. Draw a Nasion-Inion line ( Nasion – Just below Glabella and Inion -External Occipital protruberance)
2. Divide the Nasion-Inion line in to 25%, 50% and 75%
3. Bregma is the point between the 25% and 50% points and Lambda is at 75% point
4. Sylvian fissure is drawn from the orbitotemporal angle (A point of depressin where eyebrow ends) to the 75% point on naso-inion line.
5. Draw a line perpendicular to the root of the zygoma starting at preauricular point
6. Central sulcus is drawn from 54% point on naso-inion line to the point where the sylvian line cuts the perpendicular line