58 APPLIED ANATOMY. 



maxillary sinus, which is quite thin, is broken with a chisel for an extent of 2 cm. 

 The infra-orbital canal is opened from below, from the surface clear back to the pos- 

 terior wall of the sinus. The infra-orbital nerve is then brought down into the sinus 

 to serve as a guide to the foramen rotundum. Care should be taken (by opening 

 the canal with comparatively blunt instruments) not to wound the infra-orbital artery. 

 Then break a hole in the posterior wall of the sinus. This is very thin, and not over 

 half a centimetre (^ in. ) intervenes between it and the anterior wall of the sphenoidal 

 sinus, so that care should be taken not to drive the chisel too far back. The pos- 

 terior wall having been broken with the chisel and the pieces picked away, the nerve 

 is dragged downward, freed as far back as possible, and pulled loose. Traction on 

 the nerve brings the ganglion forward, and with forceps it is then drawn out. The 

 bleeding, after breaking through the posterior wall of the sinus, may be very free. 

 Meckel's ganglion lies in the sphenopalatine fossa just below the maxillary nerve 

 after it leaves the foramen rotundum. Two short branches unite the ganglion and 

 nerve. It is here that the internal maxillary artery, in the third part of its course, 

 divides into six branches: the infra-orbital and posterior dental, the posterior or 

 descending palatine and Vidian, and the pterygopalatine and sphcno- or nasopalatine 

 arteries. If these arteries are wounded, as they are very apt to be, the bleeding is 

 very free. To control it temporary packing is at first resorted to. If it persists, the 

 nerve is removed as well as possible and the bleeding stopped with gauze. This 

 may be firmly packed into the opening through the posterior wall at the upper inner 

 portion of the sinus, but care should be taken not to push it roughly through the 

 fossa and into the sphenoidal sinus (or cells) beyond. 



J. D. Bryant {Operative Surgery, vol. i, p. 243) in cases of severe hemorrhage 

 advises the prompt ligation of the external carotid artery, a procedure not, however, 

 often required. It has been suggested that instead of making the incision on the 

 cheek to make it in the mouth above the gums, and pull the cheek and mouth 

 upward and outward. This procedure, while obviating the scar, makes the opera- 

 tion somewhat more difficult. Kocher resects the malar bone with the outer wall of 

 the sinus and turns it up, bringing it back into place on the completion of the 

 operation. 



Operating from the Side Through the Pterygoid Fossa. Both the 

 maxillary and mandibular branches have been reached by this route; the former at 

 the foramen rotundum and the .latter at the foramen ovale. Liicke, of Strasburg, 

 was the pioneer of the operation on the maxillary nerve, and Joseph Pancoast, of 

 Philadelphia, on the mandibular. Liicke' s operation was modified by Lossen, of 

 Heidelberg. Recently, Mixter, of Boston, has again advocated the method. A 

 convex flap, base down and reaching ^ inch below the zygoma, is cut from the 

 external margin of the orbit to the lobe of the ear. The zygoma is sawed through, 

 and, with the masseter, pulled downward. Maurice Richardson, in describing Mix- 

 ter' s operation (Internal. Textbook of Surg., vol. i, p. 863), says that "if the 

 operator is skilled enough in the subsequent manipulations, he may omit cutting the 

 temporal muscle." It will be easier, however, to divide the coronoid process and 

 turn the temporal muscle upward, clearly exposing the infratemporal crest. Detach 

 the upper head of the external pterygoid muscle and push it downward, exposing 

 the external pterygoid plate. Chisel off the spur at the anterior extremity of 

 the infratemporal crest, and immediately in front and to the inner side is the supe- 

 rior maxillary nerve, with the terminal portion of the internal maxillary artery 

 just below it. Immediately posterior to the root of the pterygoid plate is the 

 foramen ovale and mandibular nerve, with the middle meningeal artery a little 

 posterior to it. 



Anatomical Comments. The incision at its posterior extremity can be 

 made to avoid cutting the temporal artery by feeling its pulsations, about a centimetre 

 or less in front of the ear, as it passes over the zygoma. The incision should not 

 involve the deep structures only the skin and superficial fascia. Therefore, the 

 facial nerve and parotid duct (a finger's breadth below the zygoma) will not be 

 injured. 



In clearing the upper surface of the zygoma, it will be necessary to cut through 

 the layers of the temporal fascia; between them the orbital branch of the temporal 



