CHAP. VIII. Of the upper Iaw.
THE Jaws are two, the upper and the lower, constituting the outer part of the Face.
I. The upper comprehends the lower and lateral Parts of the Orbit of the Eyes, the Nostrils, Cheeks, Palate and the whole Order of the upper Teeth.
This in Men is short and semicircular for handsomeness sake. In Brutes long. Moreover it is immoveable in Man, as it is in most other Creatures, unless Parrots, Phoenicopters and Crocodiles, unless there be any other Creatures un∣known to us that move the upper Jaw.
II. The Substance of it is solid, but cavernous within, especially to∣ward the Teeth; in which place, in Children the Marrowy Juice is contain∣ed for the Nourishment, but that being consumed by Age, the cavernous Bones remains. Highmore having diligently scarched into this Cavernosity, found on each side, under the lower Seat of the Eye, where the Bone jets forth for the Guard of the Eye, a certain Den, seated at the lower sides of the Nose, remark∣ably hollow, spherical and somewhat oblong, and covered with a thin bony Scale, in the bottom of which, certain Protuberances rise up, wherein the slender Points of the Roots of the Teeth are included. This Den is frequently empty, but sometimes found full of S•…•…ime, which he believes distils through a certain Cavity from the little Caverns of the Fore-head Bone and the Eth∣moids.
III. It receives Blood for Nourish∣ment through the Branches of the Soporal Arteries, and the remainder after Nourishment, it sends through little Veins to the External Jugular. It is composed of twelve Bones, six on each side, all joyned together by Har∣monies, rather than thin Sutures.
- The First, almost triangular, is seated at the outer Corner of the Eye. This by means of its Apophysis, joyned with the foremost Process of the Temporal Bone, by an oblique Suture, forms the Iugal Bone, which being gibbous with∣out, and hollow within, covers the Temple Muscle.
- The second, which is small, thin, pellucid and brittle, constitutes the Cor∣ner of the Eye, and in this the La∣chrymal Hole is pervious to the Nostrils, through which the serous Humor distil∣ling from the Ventricles of the Brain, causes Tears in the Eyes, Vid. Lib. 3. Cap. 14. But to stop their continual flowing, there is a little Caruncle which lies upon this Hole, which hinders the ordinary Efflux, but gives way to it when more violent. Sometimes near this tender Bone, about the Top of the Nose, and the bigger Corner of the Eye, certain Abscesses happen, which the Greeks call Aegylopas, which if neglected, corrode the Bone it self, and cause a La∣chrymal Fistula.
- The Third is thin and pellucid, within the inner side of the Orbit of the Eye, interposed between the rest, and more inward continuous to the spungy Bones of the Nostrils.
- The Fourth is the least Bone of all, which constitutes the most porous Parts of the Cheeks and Palate, and receives the upper Row of the Teeth into its Caverns. It has a conspicuous Hole, seated under the Orbit of the Eye, producing a Branch of the third Pair of the Nerves to the Face; also another Hole at the hinder Part of the cutting Teeth, in the middle bony Fence, again divided into two Holes toward the up∣per Parts. Of which, one tends to each Nostril, and r•…•…mits a little Vein thither out of it. Some think that the Spitly Humors, descending this way to the Nostrils, flow into the Mouth; which is not probable. Moreover, under the Orbit of the Eye, at the lower side of the Nose, there is a remarkable Hollowness, which however in Children is not easily found, but is hollowed by Age.
- ...