62 



The Cranial Nerves 



To reach the supra-orbital nerve a horizontal incision is made for 

 about three-quarters of an inch, just above the border of the orbit the 

 skin, superficial fascia, orbicularis palpebrarum, and occipito-frontalis 

 being traversed. The middle of the incision should be just above the 

 supra-orbital notch, which can be made out by the finger. When 

 instead of a notch there is a complete foramen in the bone the site of 

 the nerve can be ascertained by pressure ; it emerges at the junction of 

 the inner middle thirds of the supra-orbital ridge. 



When it is suspected that a person is shamming insensibility, steady 

 pressure should be kept up with the finger on the nerve, just over the 

 supra-orbital notch. No impostor could bear this for long, and he may 

 thus be conveniently and promptly tested. 



The superior maxillary division leaves by the foramen rotundum, 



SENSORY NERVES 



1, Great Occipital. 



2, Lesser Occipital. 



3, Arnold's. 



4, Great Auricular. 



5, Auriculo-Temporal. 



6 and 9, Temporo-Malar. 



7, Supra-Orbital. 



8, Supra-Trochlear. 

 10, I nfra-Trochlear. 

 TI, Nasal. 



12, Infra-Orbital. 



13, Buccal Branch of Inferior 



Maxillary. 



14, Mental. 



(HOLDEN.) 



runs across the spheno-maxillary fossa, and, coursing beneath the floor 

 of the orbit, emerges by the infra-orbital foramen under cover of the 

 levator labii superioris. It then spreads out into branches for the nose, 

 lower eyelid, and upper lip. It gives off an orbital branch which divides 

 into a temporal and a malar twig, which pierce the outer wall of the 

 orbit to supply the skin in the temporal and malar regions respectively. 

 Other branches of the trunk are the sensory root to Meckel's ganglion ; 

 the posterior dental, which forms a loop in the bone and gives off 

 twigs to the lining of the antrum, to the pulp-cavities of the molar 

 teeth, and to the gums. 



The anterior dental runs down in the front wall of the antrum to 

 supply the incisors, the canine, and the bicuspids. 



