THE FIFTH, TRIQEMIN^L, OR TRIFACIAL NERVE 995 



passing along the lower margin of the orbit, the other from the centre of the first cut vertically 

 down the cheek toward the angle of the mouth. The nerve is then found, is divided, and a 

 piece of silk is tied to it as a guide. A small trephine (one-half inch) is then applied to the bone 

 below, but including the infraorbital foramen, and the antrum opened. The trephine is now 

 applied to the posterior wall of the antrum, and the sphenomaxillary fossa exposed. The 

 infraorbital canal is now opened up from below by fine cutting pliers or a chisel, and the nerve 

 drawn down into the trephine hole, it being held on the stretch by means of the piece of silk; 

 it is severed with fine curved scissors as near the foramen rotundum as possible, any branches 

 coming off from the ganglion being also divided. 1 



The mental branch of the inferior dental nerve may be divided at its exit from the foramen 

 through an incision made through the mucous membrane where it is reflected from the alveolar 

 process on to the lower lip ; or a portion of the trunk of the inferior dental nerve may be resected 

 through an incision on the cheek through the Masseter muscle, exposing the outer surface of 

 the ramus of the mandible. A trephine is then applied over the position of the inferior dental 

 foramen and the outer table removed, so as to expose the inferior dental canal. The nerve is 

 dissected out of the portion of the canal exposed, and, having been divided after its exit from 

 the mental foramen, it is by traction on the end exposed in the trephine hole, drawn out entire, and 

 cut off as high up as possible. 2 The inferior dental nerve has also been divided through an in- 

 cision within the mouth, the bony point guarding the inferior dental foramen forming the guide 

 to the nerve. The buccal nerve may be divided by an incision through the mucous membrane 

 of the mouth and the Buccinator muscle just in front of the anterior border of the ramus of the 

 mandible (Stimson). 



In inveterate neuralgia of one or two of the branches of the trigeminal nerve a peripheral 

 operation may cure the case, but seldom does. It often gives relief, perhaps for months. In 

 neuralgia of the second division or third division, or of the second division and third division, 

 Abbe, of New York, opens the skull and divides the nerve or nerves by an intracranial opera- 

 tion, removes a piece of nerve so that the foramen of exit is empty, and covers the foramen with 

 rubber tissue, to hinder regrowth of the nerve. Other operators, after removing a piece from 

 each nerve, have plugged the foramina of the exit with dentists' cement or silver foil. 



Rose's method of neurectomy is very valuable for neuralgia of the second division. It is a 

 modification of the Braun-Lossen method. The infraorbital nerve is exposed, a ligature is 

 tied about it, the roof of the infraorbital canal is chiselled open, and the nerve is freed as far 

 back as possible. An incision is made from below the external angular process outward along 

 the zygoma to in front of the lobule of the ear, downward to just above the angle of the mandible, 

 and forward for two inches. The flap is raised and the zygoma is exposed. The root of the 

 zygoma is drilled at two points, and the zygomatic process of the temporal bone is drilled at two 

 points. The bone is sawed in two places between the drill holes. The freed arch is lifted down 

 and back, the tendon of the Temporal muscle is drawn backward, and the pterygomaxillary 

 fossa is thus exposed. The internal maxillary artery is divided between two ligatures. The 

 External pterygoid muscle is separated from the greater wing of the sphenoid and from the root 

 of the external pterygoid process. The superior maxillary nerve is grasped and twisted off as 

 near the ganglion as possible. The entire nerve is then drawn back from the infraorbital foramen 

 and removed. The wound is then closed. If the third division is also haunted by neuralgia, 

 it too should be removed a few weeks after the performance of Rose's operation. 



If a peripheral operation fails, or if all the branches of the trigeminal are involved, the Gas- 

 serian ganglion must be removed, or the sensor root of the trigeminal must be divided, as sug- 

 gested by Frazier and Spiller. 



Removal of the Gasserian ganglion was suggested by J. Ewing Mears in 1884, and was first 

 carried out by Rose in 1890. The method chiefly in vogue was devised by Hartley, and was 

 first performed by him in 1891. An osteoplastic flap is made in front of the ear, the dura is 

 exposed and lifted. Following Krause's advice, the third division is exposed and clamped. 

 The second division is exposed and clamped. The nerves are loosened from their beds and 

 then are rolled about the clamps. This twisting pulls out the ganglion intact along with the 

 motor root, and also the sensor root from the pons. A difficulty in the Hartley operation is the 

 danger of division of the middle meningeal artery. If this happens, the surgeon may be able 

 to arrest bleeding and proceed with the operation. If the vessel is torn off at the foramen spi- 

 nosum, it will be necessary to pack the wound and postpone any further operative manipulation 

 for forty-eight hours. Dr. Harvey Gushing has modified Hartley's operation by trephining the 

 wall of the temporal fossa very low down. He opens the skull below the arch of the meningeal 

 vessels, and thus avoids the middle meningeal artery at the foramen spinosum, and also the 

 sulcus arteriosus of the parietal bone. After the removal of the ganglion, Professor Keen, 

 in order to prevent undue inflammation of the eye, sews the eyelids of the affected side together, 

 leaving a space open at each angle, and covers the eye with a watch crystal. Boric acid solution 



' Car 

 2 Mea 



nochan, American Journal of the Medical Sciences, 1858, p .136. 

 ars, Transactions of the American Surgical Association, vol. ii, p. 469. 



