Fig. 3
From: Mastoid notch as a landmark for localization of the transverse-sigmoid sinus junction
Illustration of the coordinate system on the left side of a skull sample. The X-axis is established by the horizontal line connecting points A and B, which are located where the upper edge of the ZA joins anteriorly to the FPZ and blends posteriorly into the SMC, respectively. The Y-axis is defined by a line through the tip of the mastoid (Point C) and perpendicular to the X-axis. The red, yellow and green circles represent the TMN, IMTS and ASTS, respectively. FPZ: frontal process of the zygomatic bone; ZA: zygomatic arch; SMC: supramastoid crest