KINDS OF TEETH 



95 



teeth are hard bodies set at intervals in two semicircular 

 rows of sockets. These sockets are formed for the purpose 

 in the bones called the jaws. The teeth are surrounded by 

 a layer of flesh which we call the gums. Though hard like 

 bone they are not of the same structure but are actually 

 hardened masses of epithelial tissue. In the hfe of a man 

 or woman two sets of teeth are developed. The milk teeth 

 are the first to appear, and are shed early in life. The 

 second teeth, or permanent set, begin to appear before the 

 milk teeth are all gone, and gradually replace them. These 

 two sets agree in their origin and general structure but 

 differ in number. There are twenty milk teeth and thirty- 

 two permanent teeth. 



Kinds of teeth. — (See Fig. 26.) Teeth of the same set 



d 



Pig. 26 — Kinds of teeth ; a, incisors ; 6, canines ; c, bicuspids or premolars ; 

 rf, molars. 



differ in shape. For example, in the permanent set there 

 are found in front, eight teeth, with broad chisel-shaped 



