Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 9 On the Twelve Bones of the Upper Maxilla, Including the Bones of the Nose

Why the maxilla consists of several bones, both hollow and light

The upper maxilla is formed not from a single bone but from several, chiefly to make it more resistant to damage, so that when one portion of it is hurt the entire maxilla will not be directly affected and the trouble will stop with a single bone (as has also been stated regarding the structure of the cranial bones). Also, because all its parts did not need to be equally solid, dense, and hard, it was necessary that it be made up of several bones. It is constructed of particularly hard but rather light bones, for the foramina of the nostrils are so large and open that the maxilla gains a remarkable lightness for such a mass. Other openings and air-filled cavities [sinus paranasales] hidden inside the bones are so large and hollow that the upper maxilla on both sides near the nasal cavities is discovered to be somewhat like the waxen images which we pour into various moulds and leave hollow inside. 25 In this part one cannot agree with Galen, who teaches that the upper maxilla is without marrow and constructed of hard bones that have no need of lightness because this bone, unlike the lower maxilla, does not move. 26 But in fact the lower maxilla is much stronger, and is made of far tougher bone to resist injury and is much less prone to be eaten away by Gallic scabies. 27



Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 9 On the Twelve Bones of the Upper Maxilla, Including the Bones of the Nose