spine of sphenoid bone spine of sphenoid bone the sphenoidal spine (latin: "spina angularis") is a downwardly directed process at the apex of the great wings of the sphenoid bone that serves as the origin of the sphenomandibular ligament. spine of sphenoid bonesphenoid bone. upper surface. (spina angularis labeled at bottom left.)articulation of the mandible. medial aspect. (spine of sphenoid labeled at center top.)detailsidentifierslatinspina ossis sphenoidalis, processus spinosus ossis sphenoidalista98a02.1.05.040ta2626fma54777anatomical terms of bone additional images base of skull. inferior surface. spine of sphenoid bone marked with black circle