Chap. IX. Of the Bones of the Jaw in General.
THe Jaw-Bones are the foundations of the whole Face, the upper above the mouth the lower beneath.
For the upper, which Celsus calls Mala, is the boney part of the Face, comprehending the lower and lateral parts of the Eye-socket, the Nostrils, the Cheeks, the Pa∣late, and the whole row of the upper Teeth.
And this Jaw-bone in Mankind, is shorter and round∣er than in Brutes, for Beauties sake, also it is immoveable as it is in Beasts, saving the Parrot, the Phaenicopterus, and the Crocodile as wel that which lives in the water, as the Land-Crocodile; yet do they not move the upper Jaw only, but their whole Head withall being straitly fasten'd thereto, as Vipers do, and the like is to be said of the Parrot.
But the lower Jaw-bone in Mankind and other Crea∣tures, is only movable, save in the Crocodile, which hath it so united to the Bones of the Temples, that it can no waies be stirred; but the Parrot moves both.
The Connexion is without motion in the upper Jaw, by a Suture or Harmonie whereby it is joyned with many bones of its own, of which it is composed, and other bones placed round about; in the lower by way of Sun∣chondrosis, which is in the middle of the Chin. But in grown persons, the Gristle is so turned into a Bone, that the lower Jaw seems to be one only bone, whereas before it consisted of two.
In the Brim or Circuit of each Jaw-bone, which place Galen calls Ph••••••••an, we meet with Cavities, wherein the Teeth are fasten'd, which Galen terms Bóthria, the Latines Alveolos, Loculos, Fossulas, Praesepiola, Morta∣riola.
These holes according to the nature of the teeth in them, are somtimes single, otherwhiles threfold: somtimes they are obliterated and shut up, the Teeth being fallen or pluckt out. Somtimes they breed anew, by fresh Teeth breaking out. In old Age, frequently these holes are obliterated, the Teeth being lost, and the Gums become sharper and harder, so that old folks chew their meat with them instead of Teeth.