DENTIGEROUS CYSTS IN THE TEMPORAL REGION. 3 



did not notice the existence of the svveUing. One morning, however, 

 he remarked on the left side of the animal's head a swelling the size 

 of a small egg. Being unable to obtain any exact information as to 

 its nature and gravity he sent the horse here. At the first examina- 

 tion it was easy to see that we had not to deal with an abscess. The 

 swelling was uniformly soft, fluctuating, cold, and painless. Its posi- 

 tion in front of the ear and above the zygomatic process, its sharp 

 dehmitation, the absence of inflammatory symptoms, and the dis- 

 covery of a prominence of bony consistence in the depths, sufficiently 

 suggested its nature. It was, in fact, a dentigerous cyst. The owner 

 did not wish to run the risks of treatment, and removed the horse. 



In October last I operated on a two-year-old colt, which showed 

 an open sinus about three eighths of an inch in front of the base of 

 the ear. This sinus, which ran obliquely forwards and was about 

 four inches long, ended over a kind of rough bony swelling, which 

 was regarded by some of you as an exostosis, by others as a necrotic 

 patch of bone. The animal having been cast, and the front of the 

 fistula laid open, we discovered a rounded prominence of bony con- 

 sistence, with an irregular summit and smooth sides. It was, in fact, 

 a supernumerary tooth. I seized it with dental forceps and attempted 

 to loosen it. It readily became detached, and when extracted had the 

 appearance of a small molar. A little behind was another, which 

 I removed without much difficulty. The cavities left by these teeth 

 were rounded, regular, and partly lined with fibrous membrane. 

 Haemorrhage was trifling. The cavities were curetted and plugged 

 with gauze. The dressing was renewed in forty-eight hours and 

 several times later. In a month the wound had healed. 



In 1888 I saw another case of this kind, in which intervention was 

 equally simple and cure rapid. Towards the middle of September a 

 six-year-old horse was sent to the external Clinique, with an old 

 sinus in front of the ear. The margins were denuded of hair, 

 hardened, and from them escaped a little greyish, laudable pus, with- 

 out offensive odour. A probe introduced into this sinus was finally 

 stopped by a raw, bony surface, and by manipulating it a little I was 

 able to satisfy myself of the presence of some hard moveable body, 

 like a sequestrum. Having opened up the fistula, I removed this 

 body with a pair of bent-necked forceps. It proved to be a small 

 molar, completely detached, and held in its alveolus by a root little 

 larger than the crown. The walls of the cavity were scraped, and 

 the parts washed out with strong carbolic solution. Suppuration 

 proceeded for several weeks, doubtless because of some change in the 

 bone, but the wound eventually healed. 



