1374 SUKFACE AND SUKGICAL ANATOMY. 



enlarges, it frequently does so by projecting downwards towards the sphenoidal 

 sinuses rather than upwards into the cranial cavity. 



The sphenoidal sinuses constitute the surgeon's guide to the hypophysis. 

 To reach them he traverses the upper portions of both nasal cavities, removing, 

 from before backwards, the upper portion of the septum nasi, the superior and 

 middle conchse, and the anterior and posterior ethmoidal cells. The rostrum 

 sphenoidale, situated at the superior and most posterior part of the nasal septum, 

 serves as a guide to the anterior wall of the sphenoidal sinuses ; after removing it 

 the sinuses are opened up by removing their anterior walls and the septum. 

 The hypophysis is then exposed by breaking down the anterior portion of the 

 floor. of the sella turcica, which forms a bullous-like projection into the superior and 

 posterior part of the sinuses. In making the opening from the sphenoidal sinuses 

 into the hypophyseal fossa, the surgeon must keep strictly to the median plane, so 

 as to avoid opening into the cavernous sinus ; if the roof of the sinus be 

 penetrated in front of the fossa the optic chiasma would be injured and the cranial 

 cavity opened, while if the posterior wall of the sinus be penetrated below the 

 level of the fossa hypophyseos the spongy tissue of the body of the sphenoid 

 would be opened into, and if the sinus happened to extend unusually far back, 

 the anterior part of the posterior fossa of the base of the skull would be opened 

 into opposite the basilar artery and the ventral surface of the pons. 



According to Stanley Gibson, the average distance from the nasion to the 

 anterior superior margin of the sphenoidal sinus is If inches, while the distance 

 from the anterior superior boundary of the sinus to the anterior superior margin 

 of the sella turcica is a little more than J inch, so that the total distance from the 

 nasion to the hypophysis is from 2J to 2J inches. The average distance from the 

 anterior nasal spine to the hypophysis is 7*8 cm. (practically 3 in.). The floor 

 of the hypophyseal fossa is on a level with a plane projected backwards from 

 the nasion to the inion. The fossa measures J inch in its antero- posterior 

 diameter. 



In a profile skiagram of the skull, the outline of the cup-shaped sella turcica 

 is marked out by a crescentic linear shadow, the anterior and posterior horns 

 of the crescent being represented by the shadows of the anterior and posterior 

 clinoid processes. Below and in front of the fossa the outlines of the sphenoidal 

 sinuses may be distinctly traced. (Plate I.) 



Enlargements of the hypophysis cerebri can often be clearly demonstrated by 

 an increase in the depth and antero-posterior diameter of the skiagraphic outline 

 of the sella turcica, and by the unusual extent to which the fossa encroaches upon 

 the sphenoidal sinus. 



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 imbedded the 

 facial muscles as well as the 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 line 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 piriform opening and the anterior nasal spine, the supra- and infra- 

 orbital margins, the zygomatic process of the frontal bone, the medial angular process, 

 the anterior part of the temporal crest, the zygomatic bone, the zygomatic arch, and 

 the region of the canine fossa of the maxilla. 



Immediately inferior to the root of the zygoma, and in front of the superior 

 part of the tragus, is the condyle of the mandible. By pressing with the point of the 

 finger upon the condyle while the mouth is being widely opened, the bone will be 



