52 VETERINART DENTAL SURGERT. 



The upper molars have two grooves or depres- 

 sions on the outer surface instead of one, the anterior 

 being the deeper of the two. Their inferior external 

 edges are sharp and ragged. The infero-internal 

 edge is somewhat rounded and only presents sharp 

 points in exceptional cases. The upper teeth are 

 much wider than the lower, and have much longer 

 roots. The grinding surface of the lower molars is 

 slightly concave, those of the upper slightly convex, 

 although in most mouths a straight edge will touch 

 all the teeth in a row if laid on their grinding sur- 

 face. 



The roots of the upper teeth all incline slightly 

 backwards. In the lower jaw the roots of the anter- 

 ior three molars point slightly forwards, and the 

 roots of the posterior three point slightly back- 

 wards, leaving a small space between the third and 

 fourth molar teeth until they thoroughly develop. 

 In some instances this space exists throughout life, 

 affording a place for foreign substances and food to 

 become lodged. 



The incisor teeth meet edge to edge, and at five 

 to six years the bodies are nearly perpendicular to 

 one another. As the horse grows older they assume 

 more of a horizontal appearance (stand out), until, 

 in very old animals they sometimes have their inside 

 surface nearly intact; they, like the molars, are the 

 largest in the upper jaw. 



