TEMPORARY TEETH DISCUSSED 



249 



It would be well, before proceeding further, to turn 

 to Figs. 74 and 78 and notice how the wear from year 

 to year results in a change of the form of the tooth 

 and, in time, in ob- 

 literating the cups, 

 or marks. 



Note also the dif- 

 ference in the shape 

 of the root of the 

 permanent tooth, 

 Fig. 74, and the 

 temporary tooth , 

 Fig. 62. The root of 

 the latter is much 

 smaller and shorter 

 than the former. It 

 also has a distinct 

 neck, which, however, is not easily discovered at first, 

 as the gums partially cover the neck. As the milk- 

 tooth approaches three years of age, its 

 roots are absorbed rapidly and the neck is 

 easily discovered. By the time the perma- 

 nent tooth is ready to appear, the root of 

 the temporary tooth is nearly absorbed and 

 little remains besides that portion which is 

 above the neck. The temporary teeth not 

 only have a distinct neck but are smaller, 

 smoother and lighter colored than the 

 permanent teeth. These differences may 

 FIG. 62. assist the beginner in distinguishing the 



A temporary, or . . _ . . , . , . . 



milk tooth. two kinds oi teeth and in determining age. 



FIG 

 Eight to ten months of age. 



