%t m 



LINING MEMBRANE. 41 



of the superior molares, bicuspides, and cuspi- 



dati often protrude through the inferior wall of 



the antrum, or are covered only by a very thin 



layer of its substance : hence it follows, that 



diseased teeth are the most common cause of 



inflammation of the lining 



membrane. Occasionally, 



part of the floor is brought 



away with a tooth in the 



operation of extraction f^^- 15. 



/t:i' -• ^'\ n J* 1 Part of the floor of the Antrum nttufhed 



(Fig, 1 5) . Sometimes al- tv the fangs of a molar Tooth. 



veolar abscess produces 



absorption, and its secretion passes into the 



antrum (Fig. 11). 



Inflammation may also be produced by blows, 

 foreign bodies, obstructions of the proper open- 

 ing by tumours, &c. ; syphilis, necrosis, irregular 

 dentition, pressure during parturition, &c. 



It may assume the catarrhal, rheumatic, stru- 

 mous, phlegmonous, or erysipelatous forms. 



An interesting case in an infant only two weeks 

 old, where the disease was caused by pressure 

 of the face upon the arch of the pubis during 

 delivery, has been published by the late Dr. Gr. 

 A. Rees. {Medical Gazette, vol. iv., N.S., p. 860.) 



Another, arising from irregular dentition, is 

 recorded by M. Gensoul, of " a child aged thirteen, 

 whose antrum was distended with a large collection 

 of yellow fluid, caused by a canine tooth which 

 was found at the bottom of the cavity adhering to 



