•56 
DENTAL FISTULA. 
sound, about half a line in thickness, being introduced, meets with a 
haid substance tooth, bone, &c. Round the external opening and over 
the course of the canal the bone is rarefied and swollen. Mastication is 
not. always impeded. Examination usually betrays signs of alveolar 
periostitis in the affected tooth. 
Prognosis. Removal of the diseased. tooth is essential. Hertwig 
describes a cure after application of the actual cautery and mopping 
with tincture of aloes, but such recoveries are exceptional. When the 
lower pre-molars have become diseased from external injury, recovery 
sometimes takes place without removal of the tooth. But usually the 
carious, root continues to promote pus formation, and regenerative 
processes are unequal to the task of separating the necrotic tissue—a 
condition obviously very unfavourable to healing. Moreover, in such 
cases there is generally a difficulty in extracting the tooth. In fistula 
affecting the upper jaw a radical cure is impossible without removal of 
the tooth. In prognosis account must be taken not only of the dis¬ 
turbances caused by the diseased tooth, but also of the dangers of 
extraction. Where inconvenience is slight, it may appear advisable to 
refrain from treatment. If, however, the fistula opens into the upper 
maxillary sinus or nostril, the tooth must be removed and the sinus 
trephined. Where perforation into the nostril is attended with necrosis 
of the turbinated bones, as not infrequently happens, the prognosis is 
unfaxouiable. The nasal discharge continues after extraction of the 
tooth, and betiays the peculiar smell of bone pus. After a time pieces 
of the turbinated bones become loose, and are discharged with the 
nasal fluids. 
Where, however, perforation of the nostril and necrosis have not 
taken place, recovery usually occurs soon after removal of the tooth. 
But it is unwise to piophesy the termination—time alone can determine, 
lo detect perforation into the nostril, Gunther’s catheter for the guttural 
pouch may be employed. On introducing it into the lower meatus, the 
point wheie the fistula opens will be felt as a raised and uneven patch. 
Treatment may be attempted without sacrifice of the teeth if the fistula 
has resulted from an external injury, and produces no serious incon¬ 
venience, and if the teeth in question give no evidence of disease. 
Proceeding on general surgical principles, the canal is washed out, its 
walls scraped with the curette, and dressed with chloride of zinc (1_10), 
or iodoform dissolved in ether. Solution of lactic acid has been recom¬ 
mended. If the alveolus is diseased the tooth is removed, and little further 
attention is required. Healing is hastened by inserting a plug of tow, 
saturated with a disinfectant. This may be renewed daily. In do^s 
the molar should always be removed, even though the crown appears 
sound. 
