OPERATIONS ON THE TEETH. 353 



' The second mode of extracting molars, or that by repulsion or 

 {/ouglng, is the only one possible under all the circumstances, 

 when the prehension of a carious or diseased tooth cannot be 

 effected by the instrument used in the first method, as, for in- 

 stance, in cases of disease of the posterior molars when the carious 

 tooth is so far diseased or destroyed that not enough of its sub- 

 stance remains above the root to be reached by the forceps ; or 

 again, when the exostosis of the root has reached such dimensions 

 that it will not allow its exit from the alveolar cavity, whatsoever 

 efforts may be made to overcome its resistance. 



This operation was first recommended by H. d'Arboval, and 

 although it has been condemmed by some practitioners, is certainly 

 indicated for all operations upon the molars. All the superior 

 molars, together with the three anterior inferiors, are readily 

 reached by their roots, in trephining the external plate of the 

 bones in which they are implanted. The posterior inferiors are 

 the only ones that present any serious objections, and the trouble 

 is truly a tangible one, being nothing less than the necessity of 

 passing through the entire thickness of the masseter muscle. 



The tooth demanding removal being surely identified, and the 

 impossibility of removing it by the mouth well estabhshed, the 

 animal is thrown on the side opposite to that which is occupied 

 by the diseased organ, and placed under complete anesthesia. 

 The location of the alveolar walls, upon which the operation is to 

 be made in order to reach the root of the tooth, must be first well 

 determined. If it is one of the last three upj)er molars, it will corres- 

 pond to the sinuses. But the operator must not allow himself to 

 be deceived by the presence of a fistulous opening, which, by ap- 

 pearing on the surface of the skin to indicate the j^oint of attack, 

 may in fact mislead him by conducting him to a point consider- 

 ably remote from the diseased tooth. A positive and satisfactory 

 diagnosis being settled, and the hair being clipped, a large V or 

 cross-shaped incision is made over the spot selected for the tre- 

 phine, and carefully avoiding the infliction of any injury to the 

 muscles of the region, the sinuses are opened by removing two 

 or three circular portions, at a tangent to each other, to effect the 

 removal of a fair-sized piece of the bone. The edges or prol6nga- 

 tions which remain are levelled off with the bone forcei:)S, which 

 is certainly preferable to any other means ; or if the opening made 

 in the bone is too small, it can also be enlarged by using the same 



