Chap. VI.] NOSE AND NASAL CAVITIES. 8 1 



and maggots that have developed within the nose 

 have managed to make their way to the frontal 

 sinuses. A case is reported where epistaxis, extend- 

 ing over many years, was due to an insect (the pen- 

 tastoma tsenioides) that had settled in these sinuses. 

 One day it was sneezed out, and no further bleeding 

 occurred (Med. Times, 1876). The last-named para- 

 site is said to be often met with in the frontal sinus 

 of the dog. The antrum exists at birth, but attains 

 its largest dimensions in old age. Tumours of various 

 kinds are apt to develop in this cavity, and to distend 

 its walls in various directions. Thus the growth 

 breaks through the thin inner wall and invades the 

 nose, it pushes up the roof of the cavity and invades 

 the orbit, it encroaches upon the mouth through the 

 floor of the antrum, and makes its way also through the 

 somewhat slender anterior wall into the cheek. The 

 densest part of the antrum wall is that in relation to 

 the malar bone, and this part does not yield. There 

 is little inducement for any growth to spread back- 

 wards, although it sometimes invades the zygomatic 

 and ptery go -maxillary fossse. As the infraorbital 

 nerve runs along the roof of the antrum, while the 

 nerves of the upper teeth are connected with its walls, 

 these structures are pressed upon in growths springing 

 from the antrum, and much neuralgia of the face 

 and teeth often produced. In tapping the antrum, 

 a spot is usually selected just above the second 

 bicuspid tooth, since the bone is here thin and is 

 conveniently reached. In some cases it is suffi- 

 cient to extract a molar tooth, since the fangs of 

 these teeth often enter the cavity of the antrum. 

 The teeth usually selected are either the first or the 

 third molar. 



As the result of a fall, one of the upper teeth has 

 been entirely driven into the antrum and lost to view. 

 In one case, reported by Haynes Walton, an upper 

 G 



