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3. Nasal Bones

The nasal bones project from the frontal processes of the maxillae and

form the bony support of the upper portion of the nose (Figure 4.2).

They connect the midface to the skull (frontal bones) anteriorly in the

midline.

Figure 4.2

Illustration depicting

frontal view of the

skull.

Source: Agur and

Dalley, Figure 459

4. Orbits

The orbits have a four-walled pyramidal shape, with the apex located

medial and superior.

a. Lacrimal, Ethmoid, and Palatine Bones

The optic canal is at the apex and transmits the optic nerve. The medial

wall is composed of the thick lacrimal bone, which supports the lacrimal

sac; the thin lamina papyracea of the ethmoid bone; and, to a smaller

extent, the palatine bone.

b. Sphenoid Bone

The medial wall of the optic canal is provided by the strong lesser wing

of the sphenoid bone. The floor is composed primarily of the thin roof of

the maxillary sinus.