1 72 THE HEAD AND NECK 



to the subjacent cartilage, and inflammation in this region is 

 acutely painful. 



Excellent results are obtained from plastic operations on 

 the face, as the skin can easily be stretched while still in contact 

 with the underlying connective tissue. This latter is well 

 supplied with blood-vessels, and hence the vitality of the skin 

 is not affected. 



Cutaneous Nerves. The whole of the skin of the face, with 

 the exception of an area over the angle of the mandible, is 

 supplied by the three divisions of the trigeminal nerve. The 

 ophthalmic nerve supplies most of the area derived from 

 the fronto-nasal process (p. 191), the (superior) maxillary nerve 

 supplies the area derived from the maxillary process, and 

 the mandibular (inferior maxillary) that from the mandibular 

 arch. 



The supra-trochlear and supra-orbital nerves arise from the 

 frontal branch of the ophthalmic and leave the orbit at its upper 

 margin. The former is the more medial, and supplies a small 

 area of the skin of the forehead. The latter emerges through 

 the supra-orbital notch, accompanied by the supra-orbital 

 branch of the ophthalmic artery, and supplies the skin of the 

 forehead and the front of the scalp. This nerve may require 

 to be divided in cases of severe neuralgia. An incision is made 

 through the eyebrow immediately over the notch and is carried 

 down to the pericranium. In this way the nerve is at once 

 divided; but, to prevent regeneration, the proximal portion 

 is found by separating the lower edge of the wound from the 

 pericranium, and a piece of it is resected as it enters the flap 

 close to the notch. 



The terminal branches of the lacrimal division of the 

 ophthalmic nerve supply the skin and subjacent conjunctiva 

 of the lateral part of the upper eyelid. 



The terminal branches of the naso-ciliary (nasal) division 

 of the ophthalmic nerve appear on the face as the infra-trochlear 

 and external nasal nerves (Fig. 52). 



Branches of the infra-orbital nerve, which is the terminal 

 portion of the maxillary, supply the lower eyelid, the side of 

 the nose and the cheek adjoining it, and the upper lip. Severe 

 neuralgia, radiating over the areas indicated, is not uncommon, 

 and the infra-orbital nerve may be exposed by a horizontal 

 incision just below the infra-orbital margin and above the fora- 

 men of the same name. The incision is carried down to the 





