THE TEETH OF MAN. 



The human subject does not possess the third incisor, nor 

 the first two premolars, so that a somewhat abrupt change 

 of form in passing from the incisors to the canines, and 

 from the latter to the bicuspids, is no more than might be 



/ anticipated. 



/N Incisors. Of these there are four in each jaw ; two cen- 

 tral, two lateral incisors. Their working surfaces form 

 wedges, or obtuse and blunt-edged chisels, calculated to 

 divide food of moderate consistency. 



Upper Incisors. The centrals are very much larger 

 than the laterals, and viewed either from the back or front 

 taper with some regularity from the cutting edge to the 

 point of the root, the neck not being marked by strong con- 

 striction. The crown of the tooth, as seen from the front, 

 is squarish, or more strictly, oblong, its length being 

 greater than its breadth. 



The median side, by which it is in contact with its fellow, 



FIG. 1 ('). 



is a little longer than the distal, so that the median angle of 

 the crown is a little lower, and, as a necessary consequence, 

 a little more acute than the distal angle of the cutting edge. 

 Near to its base the crowns narrow rather abruptly, so that 

 near to the neck a space is left between the contiguous 

 teeth. 



( T ) Front and side view of a left upper central incisor. 

 a Distal surface. & Neck. c Root. 



