ANATOMY OF REGIONS. 
323 
If we suppose the animal chewing to the left, the extremity of the in¬ 
ferior maxillary is carried on that side. The left condyle will corres¬ 
pond to the glenoid cavity of the temporal, while the right one will be 
in opposition to the condyle of the same side. It will be easily under¬ 
stood that in this case the axis of the articular surfaces, superior and 
inferior, cross each other very obliquely. The part of the meniscus is 
to mould itself upon the articular surfaces, in order to render the co¬ 
aptation more perfect. If the chewing takes place on the right, the 
positions will be in an inverse condition. 
Differences. —On the ox , that joint, by virtue of its position pos¬ 
terior to the pre-eminence of the orbite and of the development of the 
horns, is much less exposed to external injuries than that of the horse. 
Aside of the peculiar form of the condyle of the maxillary, which is 
concave from side to side, there is nothing peculiar to mention. 
In th % pig the condyle is triangular, consequently it has the ten¬ 
dency to assume the elongated form of the gnawers. In carnivorous 
the condyle is exactly fitted in the glenoid cavity, and in these animals 
but two motions can take place, the opening and closing of the jaws. 
SECTION IV.—REGION OF THE CHEEK. 
This region extends from the parotid to the commissure of the lips. 
It has for basis the masseter and alveolo labialis* muscles ; it is bounded 
forward by the temporal, orbito palpebral region and that of the chanfrin; 
behind by all the extent of the posterior border of the branch of the 
maxillary. 
A.—MASSETERINE REGION. 
It is separated from the alveolo-labial region by the anterior 
border of the masseter ; it is flat or slightly convex. It presents five 
layers. 
The skin is thin and loose, covered with fine short hairs. The 
subcutaneous cellular tissue , more abundant in low bred animals, is 
never much developed; it is never loaded with fat. 
The panniculus carnosus is spread under the skin over the whole 
region. It is thin, and even very often its fibres are isolated and united 
together only by the subcutaneous connective tissue. On its internal 
face are found some arteriols and the ramifications of the facial nerve. 
The masseter muscle, which gives its name to the region and 
occupies all its extent, is very thick, formed of slightly radiating fibres 
which rise from the zygomatic crest and are attached upon the pos- 
* Buccinator of Percival. 
