orbital sulcus orbital sulcus the inferior or orbital surface of the frontal lobe is concave, and rests on the orbital plate of the frontal bone. it is divided into four orbital gyri by a well-marked h-shaped orbital sulcus orbital sulciorbital surface of left frontal lobe.detailsidentifierslatinsulci orbitalesneuronames79ta98a14.1.09.217ta25465fma83770anatomical terms of neuroanatomy additional images cerebrum. inferior view. cerebrum. inferior view. deep dissection. wikimedia commons has media related to orbital sulcus.