332 



S. N. BIIASKAR 



osteoclasis in the ia rat is prol)ably due to some defect in the bone 

 tissue itself rather than in the osteoclasts or the parathyroid glands. 

 This belief is strengthened by the fact that grossly the ia bone looks 

 more basophilic, is composed of thinner trabeculae, and contains 

 more resting lines than normal (Figs. 10 and 11). 



The ia jaws demonstrate the complete dependence of normal 

 odontogenesis upon the modeling resorption of the bony crypt. 



Bone Remodeling in Shedding of Teeth 



Man has two sets of teeth, the primary or deciduous and the 

 permanent or secondary. The deciduous or primary teeth are lost or 

 exfoliated at, or before, the emergence of the permanent teeth. This 

 process is called shedding of teeth. It consists of a progressive re- 



FiG. 12. A portion of the human mandible showing the bicuspid teeth (un- 

 erupted) and deciduous molars. The bicuspid on the right has already replaced 

 part of the socket of the deciduous tooth. ( X 6.) 



