THE DIGESTIVE SYSTEM 



I6 5 



teeth. Because the first set is temporary it should not 

 therefore be neglected. Cavities in these should be filled 

 and the teeth kept clean. Before the temporary set has 

 gone the first of the permanent set appear. The first of 



KINDS OF TEETH 

 Incisors ::: 



Upper 



TIME OF APPEARANCE 



7tb Month 



9th " 



18th " 



TEMPORARY SET 

 Upper 



Lower 

 PERMANENT SET 



Fig. 56. TEETH: Kinds, Arrangements, and Times of Appearance. 



these, often called the " six-year molars," are just back of 

 the hindermost "milk molars." These should receive 

 especial care, as they will never be replaced. Any begin- 

 ning of decay in them ought to receive prompt attention. 



