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The superior bony margin of the orbital rim, otherwise known as the orbital process, is formed by the frontal bone. [7] The roof (superior wall) is formed primarily by the orbital plate frontal bone, and also the lesser wing of sphenoid near the apex of the orbit. The orbital surface presents medially by trochlear fovea and laterally by ...
Frontal bone. Inner surface. (The Pars orbitalis is the bottom third.) The orbital or horizontal part of the frontal bone (pars orbitalis) consists of two thin triangular plates, the orbital plates, which form the vaults of the orbits, and are separated from one another by a median gap, the ethmoidal notch.
Its anterior margin, smooth and rounded, is part of the circumference of the orbit. Its superior margin, rough, and directed horizontally, articulates with the frontal bone behind the zygomatic process. Its posterior margin is serrated for articulation, with the great wing of the sphenoid and the orbital surface of the maxilla.
The supraorbital foramen is a small groove at superior and medial margin of the orbit in the frontal bone. It is part of the frontal bone of the skull. [2] It arches transversely below the superciliary arches and is the upper part of the brow ridge. It is thin and prominent in its lateral two-thirds, but rounded in its medial third. [3]
This feature is different from the supraorbital margin and the margin of the orbit. Some paleoanthropologists distinguish between frontal torus and supraorbital ridge . [ 2 ] In anatomy, a torus is a projecting shelf of bone that unlike a ridge is rectilinear, unbroken and goes through glabella . [ 3 ]
Beneath each superciliary arch is a curved and prominent margin, the supraorbital margin, which forms the upper boundary of the base of the orbit, and separates the squamous part from the orbital portion of the bone. The lateral part of this margin is sharp and prominent, affording to the eye, in that situation, considerable protection from ...
On its orbital surface, just within the orbital margin and about 11 mm below the zygomaticofrontal suture is a tubercle of varying size and form, but present in 95 per cent of skulls (Whitnall 43). This tubercle is not seen in the picture. The orbital process is a thick, strong plate, projecting backward and medialward from the orbital margin ...
The frontal bone is ossified in membrane from two primary centers, one for each half, which appear toward the end of the second month of fetal life, one above each supraorbital margin. From each of these centers, ossification extends upward to form the corresponding half of the squama , and backwards to form the orbital plate.