ANATOMY. 
That fpongy protuberance at the lower circumference of 
•this bone, where the fockets for the teeth are formed, is 
reckoned the fifth. The fixth is the horizontal plate, 
■which forms the greater part of the bafe of the noflrils, 
and roof of the mouth: its upper furface, which belongs 
to the noftrils, is very fmooth; but the other below is 
arched and rough, for the fironger adhefion of the mem¬ 
brane of the mouth, which is ltretched upon it; and in 
chewing, fpeaking, &c. might otherwife be liable to be 
feparated. The feventh rifes like a fpine from the inner 
edge of the laft, and forms a fmall part of the partition of 
the nofirils. 
The deprejfions in each maxillary bone are, i. A finuofity 
behind the orbitar procefs, made by the temporal mufcle. 
2. A pit immediately before the fame procefs, where the 
origin of the mufculus elevator labiorum communis and 
elevator labii fuperioris, with a branch of the fifth pair of 
nerves, are lodged. 3. The hollow arch of the palate. 
4. The femicircular great notch, or entry to the lower 
part of the noftrils. 5. Sockets for the teeth. 6. The 
lacrymal fulfil in the nafal procefs, which aftilts the os un¬ 
guis to form a palfiage for the lacrymal duft. The part 
of the bone forming this folfia is fo firm and ftrong, that 
a furgeon can fcarcely perforate it with the ordinary inftru- 
ments for- the fiftula lacrymalis; and therefore ought to 
avoid it in doing this operation. Immediately on the out- 
tide of this there is a fmall deprelTion, from which the in¬ 
ferior or Idler oblique mufcle of the eye has its origin. 7. 
The canal on the upper part of the great tuberofity within 
the orbit, which is almoft a complete hole; in this a branch 
of the fuperior maxillary nerve palfies. Betides thefe, the 
fuperior furface of the great bulge is concave, to receive 
the under part of the eye. Immediately above the tranf- 
verfe ridge in the nafal procefs, a fmall hollow is formed 
by the os fpongiofum. In fome fubjefts, the nafal procefs 
lias a fmall round pit above the lacrymal duft, where the 
little tendon or ligament of the orbicular mufcle of the eye¬ 
lids is inlerted. It is this tendon, and not the tendon of 
the larger oblique mufcle of the eye, which there is fome 
hazard of cutting in the operation of the fiftula lacrymalis. 
The holes of this bone are two proper and two common. 
The firft of the proper is the external orbitar, immediately 
below the orbit. The fecond is the foramen incifivum, 
juft behind the fore teeth. Through them fmall arteries 
and veins, and a twig of the fecond branch of the fifth 
pair of nerves, pafs, and make a communication between, 
or join the lining coats of the nofe and mouth. In fome 
lubjefts, Steno’s duft may be traced l'ome length on the 
fide of thefe paffiages next to the nofe, and fmall orifices 
may be obferved opening into the mouth. The firft com¬ 
mon hole is that which 'appears at the inner fide of the 
back part of the tuberofity and of the fockets of the teeth.; 
and is formed by a folfia in this bone, and a correfponding 
one in the os palati: through it a nerve, which is a branch 
of the fecond branch of the fifth pair, runs to the palate. 
The other common hole is the great flit in the outlide of 
the orbit. 
All the body of the maxillary bone is hollow, and leaves 
a large Jinus like the frontal and fphenoid, which is com¬ 
monly, but unjuftly, called antrum Highmorianum. When 
the os maxillare is (ingle, or feparated from all the other 
bones of a fkeleton, its antrum appears to have a large 
aperture into the noftrils ; but, in a recent fubjeft, it is fo 
covered at its back-part by the palate-bone, in the middle 
by the os fpongiofum inferius, before by a ftrong mem¬ 
brane, that one or fometimes two holes, fcarcely fo larg'e 
as a crow-quill, are only left at the upper part; which, 
after a fhort winding procefs, open into the noftrils be¬ 
tween the two otfia fpongiofa. At the bottom of this ca¬ 
vity, we may often obferve fome protuberances, in which 
the fmall points of the roots of the teeth are contained. 
This cavern and the fockets of the teeth are often divided 
by the interpofition only of a very thin bony plate, v\ hich 
Is liable to be eroded by acrid matter collected in the an¬ 
trum, or to be broken in drawing a tooth. The fymptoms 
Vol. I. No. 34. 
?4l 
of a collection of matter here naturally led us to the prac¬ 
tice of pulling out the teeth, and piercing through this plate 
into the antrum, to procure an evacuation of the collected 
matter, by- which confiderable fervice is frequently done. 
The maxillary bones are joined above, by the upper ends 
of their nafal procelfes to the os frbntis, by the tranfverfe 
future; at the (ides of theft? precedes, to the offia unguis, 
by the lacrymal futures; to the nafal bones, by the lateral 
nafal futures; by their orbitar precedes, to the cheek-bones, 
by the external orbitar future; by the internal fides of the 
internal orbitar procelfes, to the ofla plana, by part of the 
ethmoidal future; by the back part of the tuberofities, to 
the palate-bones, by the futliras palato-maxillares; by the 
pofterior edges of their palatine lamella, to the ofla palati, 
by the tranfverfe palate future ; by their nafal fpines, to 
the vomer, by the fpinous future; by their focket, to the 
teeth, by the gomphofis; by the internal edge of the palate- 
plate, to one another, by the longitudinal palate future, on 
the upper and fore part of which a furrow is left for re¬ 
ceiving the cartilage which forms the partition of the nof¬ 
trils ; between the fore-part of the noftrils and mouth, to 
each other, by the myftachial future : fometimes they are 
connected to the ofla fpongiofa inferiora, by a plain con¬ 
cretion or union of fubftance. 
Thefe bones form the greater part of the nofe and of 
the roof of the mouth, and a confiderable (hare of the or¬ 
bit. They contain fixteen teeth, and give rife to mufcles, 
tranfmiflion to nerves, &c. 
OJfa palati are commonly deferibed as two fmall fquare 
bones, at the back-part of the palate or roof of the mouth, 
though they are of much greater extent, being continued 
up the back-part of the noftrils to the orbit. Each palate- 
bone may therefore be divided into four parts, tire palate 
fquare-bone, the pterygoid procefs, nafal lamella, and or¬ 
bitar procefs. The J'quarc-bone is unequally concave, for 
enlarging both the mouth and cavity of the nofe. The 
upper part of its internal edge rifes in a fpine. Behind, 
this bone is fomewhat in form of a crefcent, and thick, 
for the firm connection of the velum pendulum palati; the 
internal point being produced backwards, to afford origin- 
to the palato-ftaphylinus or azygos mufcle. This fquare- 
bone is well diftinguiftied from the pterygoid procefs by a 
perpendicular folfia, which, applied to fuch another in the 
maxillary bone, forms a paflage for the palatine branch of 
the fifth pair of nerves; and by another fmall hole behind 
this, through which a twig of the fame nerve paifies. The 
pterygoid procefs is fomewhat triangular, having a broad 
bale, and ending (’mailer above. The back-part of this 
procefs has three folfise formed in it; the two lateral receive 
the ends of the two plates of the fphenoid bone; the mid¬ 
dle folfia makes up a part of what is commonly called the 
fojfa pterygoidca ; the fore-lide of this palatine pterygoid 
procefs is an irregular concave, where it receives the back- 
part of the great tuberofity of the maxillary bone. The 
nafal lamella of this bone is extremely thin and brittle, and 
rifes upwards from the narrow extremity of the pterygoid 
procefs ; where it is fo weak, and at the fame time fo firmly 
fixed to the maxillary bone, as to be very liable to be bro¬ 
ken in feparating the bones. From the part where the 
plate rifes, it runs up broad on the infide of the tuberofity 
of. the maxillary bone, to form a confiderable (hare of the 
fides of the maxillary firms, and to clofe up the (pace be¬ 
tween the fphenoid and the great bulge oi the maxillary 
bone, where there would otherwife be a large flit opening 
info the noftrils. From the middle, internal fide of tins 
thin plate, a crofs ridge, placed on (uch another of the 
maxillary bone, is extended; on it the back-part of tire 
os fpongiofum inferius refts. 
The palate-bones are joined to the maxillary, by the fore- 
edge of the palate fquare bone, by the tranlvcrle palate ft; - 
ture; by their thin nafal plates, and part of their orbitar 
precedes, to the fame bones, by the palato-maxillares fu¬ 
tures; by their pterygoid precedes, and back-part of the 
nafal plates, to the abe vefpertilionunv, by the fphcno.d 
future; by the tranfverfe ridges .of the nafal palates, to 
6 Y the 
