TWEXTY-OiXE YEARS. 



119 



Fig. 121. 



Twenty-one Years (Figs. 119, 120, 121).— The teeth become so hori- 

 zontal that, looked at in front, the inferior ones are scarcely seen unless 

 the head is well raised. The triangular interspaces at the base of the 

 superior incisors increase in size and the convergence of the free ends 

 becomes more marked. In profile, the jaws are seen diminished in size ; 

 the inferior corner teeth have become almost horizontal and have worn 

 off the notch on the superior corners. Tlie wearing surfaces of these 

 teeth become elongated from in front to behind and have lost their tri- 

 angular shape. The tables of the superior pinchers and intermediate 

 teetli are elongated from in front to behind and distinctly triangular ; 

 they are generally leveled. The tables of the inferior teeth commence 

 to flatten from side to side and are more distinctly separated. 



