110 DISEASES OF THE TEETH 



rapidly than the enamel, a cavity is soon formed within the 

 tooth but having a small opening through the enamel. As 

 this process continues it opens the pulp cavity which becomes 

 infected. As long as the opening through the enamel is free 

 the pus will be discharged without further complication but 

 if it becomes closed with food particles, etc., an abscess 

 develops at the root and the pus burrows out into the adja- 

 cent parts, usually into the sinuses or may break down the 

 sinus wall resulting in a maxillary fistula. The disintegra- 

 tion of the dental tissue is brought about by chemical action 

 from the lactic acid fermentation in the mouth. 



Symptoms. This condition will be noticed only by careful 

 inspection until the disintegrating process reaches the pulp 

 cavity when it gives rise to sharp pain, depression of the head 

 toward the affected side and careful mastication. When a 

 fistula results the pain is not pronounced. Empyema of the 

 sinuses often causes a distortion of the affected side and a 

 dull sound when percussed. Suspect all fistulse opening in 

 the maxillary region as having their origin in a carious tooth. 



Treatment. Extract diseased tooth and cleanse the alveo- 

 lus with antiseptic solution (boric acid 2 per cent.). If a 

 fistula is present, it is readily irrigated when the tooth is 

 removed. Thorough irrigation through the entire tract 

 should be done daily. Healing is usually rapid. 



