46 APPLIED ANATOMY. 



The pain is felt above the orbit radiating from the supra-orbital notch, sometimes as 

 far up as the vertex. Pain is also felt on pressure over the supra-orbital notch. If 

 the entire ophthalmic branch of the fifth nerve is affected, pain is felt in the eyeball 

 and down the side of the nose. The incision in operating may be made at the 

 lower border of the eyebrow, its centre being over the notch. If the notch is not 

 readily felt on the edge of the bony orbit at the junction of the inner and middle 

 thirds, it can be detected by feeling with the tip of the finger on the orbital surface. 

 The incision is made through the fibres of the orbicularis palpebrarum, corrugator 

 supercilii, and frontalis muscles, then through the palpebral ligament immediately 

 below the bony edge of the orbit, and the orbital fat separated with forceps; the 

 nerve is then caught with a hook before it enters the notch, and brought up 

 and removed. Considerable ecchymosis may follow this operation if the accom- 



Branches of the supra-orbital nerve 



FIG. 55. Supra-orbital nerve and artery. 



panying artery is divided. Operations on the ophthalmic division of the fifth nerve 

 have usually been done in connection with removal of the Gasserian ganglion, the 

 other branches being also involved. 



Nasion. About a centimetre below the glabella, in the adult skull, is the 

 nasion, or line of junction of the frontal and nasal bones. It is along this frontonasal 

 suture, to one side of the median line, that an anterior meningocele is apt to show 

 itself. 



The internal angular process of the frontal bone articulates with the nasal 

 process of the superior maxilla and the lachrymal bones. The line of suture is 

 continuous with the nasion in front and the upper edge of the ethmoid behind. 

 Pus originating in the ethmoidal cells, frontal sinuses, and lachrymal apparatus is apt 

 to point at this locality. The frontal bone is a favorite seat of exostoses. 



THE TEMPORAL REGION. 



The region of the temple is on the side of the head as far forward as the eye 

 and as low as the zygoma and infratemporal crest. The floor of the temporal fossa 

 is formed by the posterior portion of the frontal and anterior portion of the parietal 

 bones as high as the temporal ridge, the outer surface of the greater wing of the 

 sphenoid, and the squamous portion of the temporal bone. These four bones meet 

 to form the region of the pterion (see p. 39 and 42). The anterior edge of the 

 temporal bone overlaps and is superficial to the posterior edge of the sphenoid. The 



