EZ SURFACE AND SURGICAL ANATOMY. 
ethmoidal cells are closely related to the thin inner or nasal portion of the floor of the 
sinus and its duct of exit ; hence suppuration very frequently co-exists in both cavities 
In some cases pus flows directly from the frontal sinus and infundibulum along the 
hiatus semilunaris into the maxillary antrum, which opens into the back part of the 
hiatus. 
THE FACE. 
The skin of the face is thin, vascular, and rich in sebaceous and sweat glands ; 
it is intimately connected with the subcutaneous tissue, in which are linbedded the 
facial muscles as well as thé main blood-vessels. Owing to its elasticity and to 
the presence of the main blood-vessels in the lax subcutaneous tissue, the face is an 
admirable site for plastic operations, as the flaps do not necrose in spite of consider- 
able tension. The laxity of the tissues accounts for the marked swelling which 
attends cedematous and inflammatory conditions about the face. Whenever pos- 
sible, incisions should be made along the lne of the natural furrows and creases of 
the skin, so as to render the resulting cicatrix less noticeable. 
The bony landmarks of the face which may be readily palpated are: the 
superciliary ridges and the glabella, the nasion (fronto-nasal junction), the bridge of 
the nose, the osseous anterior nares and the nasal spine, the supra- and infra-orbital 
margins, the external and internal angular processes, the anterior part of the temporal 
crest, the malar bone, the zygomatic arch, and the region of the canine fossa of the 
upper Jaw. 
Immediately below the root of the zygoma, and in front of the upper part of 
the tragus, is the condyle of the jaw. By pressing with the point of the finger 
upon the condyle while the mouth is being widely opened, the bone will be felt to 
elide forward, while the finger sinks deeply into the hollow corresponding to the 
glenoid cavity. The close relation of the first part of the internal maxillary artery 
to the inner aspect of the neck of the jaw must be kept im mind in operations 
calling for disarticulation or exdision of the condyle. The ascending ramus of the 
jaw is sandwiched between the masseter and the pterygoid muscles, and can be 
removed without opening into the mouth. Passing downwards from the condyle, 
one can palpate the anterior and posterior borders of the ascending ramus and the 
angle and body of the mandible. The anterior border of the coronoid process is 
felt in front of the upper part of the anterior border of the masseter, immediately 
below the anterior part of the zygomatic arch. 
The pulsation of the facial artery may be felt as the vessel crosses the lower 
margin of the mandible at the anterior border of the masseter, 1 in. in front of 
the angle of the jaw. To map out the course of the artery upon the face, draw a 
line from this point to a point $ in. external to the angle of the mouth, and 
thence to a point a little behind the ala nasi and along the side of the nose to 
the inner angle of the orbit. The facial vein lies behind the facial artery, and 
takes a straighter course from the inner canthus to the anterior inferior angle of 
the masseter. The vessel is devoid of valves, hence infective phlebitis and throm- 
bosis are liable to spread along it to the cavernous sinus by way of the ophthalmic 
and pterygoid veins. 
A line projected downwards from the supra-orbital notch (junction of imner 
and middle thirds of the supra-orbital margin) to the lower border of the 
mandible opposite the interval between the two lower bicuspid teeth, will cross 
the infra-orbital and mental foramina, the former } in. below the infra-orbital 
margin, the latter midway between the upper and lower borders of the lower jaw. 
In performing the operation of neurectomy for the relief of trigeminal neuralgia, 
these foramina furnish the guides to the correspondingly-named branches of the fifth 
nerve. It should be remembered that the nerves in question, after emerging from 
their respective foramina, lie, in the first instance, beneath the facial muscles. The 
supra-orbital and infra-orbital nerves are not infrequently represented each by two 
branches, one of which passes through an accessory foramen situated external to 
the normal opening. Neurectomy of the inferior dental nerve is performed by . 
trephining the ascending ramus of the jaw midway between its anterior and pos- 
terior borders, on a level with the crown of the last molar tooth, the nerve being 
