nasion nasion the nasion (/ˈneɪziɒn/) is the most anterior point of the frontonasal suture that joins the nasal part of the frontal bone and the nasal bones. it marks the midpoint at the intersection of the frontonasal suture with the internasal suture joining the nasal bones. it is visible on the face as a distinctly depressed area directly between the eyes, just superior to the bridge of the nose. it is a cephalometric landmark that is just below the glabella. nasionrelations of the brain and middle meningeal artery to the surface of the skull. (nasion is at #1.)side view of head, showing surface relations of bones. (nasion labeled at center left.)detailsidentifierslatinnasionta98a02.1.00.015ta2417fma264779anatomical terminology