ANIMAL DENTISTRY. 235 



4th Step — Dissect the muscle and connective tissue from 

 the bone and arrest the hemorrhage. 



5th Step — Cut a circular ring in the periosteum slightly 

 larger than the diameter of the trephine to prevent tearing 

 it beyond the area of the circle. 



6th Step— Remove the skull plate with the three-fourths 

 inch trephine. 



7th Step — If a tooth is to be repulsed, enlarge the open- 



FiG. 152. 

 Surgical Areas of the Sinuses. 



A, A. Maxillary sinuses. 



B, B. Frontal sinuses. 



ing toward the median line of the head with chisel and 

 mallet, so that the punch can be placed on a straight line 

 with the tooth. 



8th Step — (See repulsion of teeth, page 161). 



gth Step — Open the skull with the one-inch trephine, at a 

 point 4 to 5 centimeters obliquely downward and inward 

 from the nasal canthus . (See Fig. 151.) 



loth Step' — Break down the thin, bony septa with the 



