330 S. N. BlIASKAR 



and histodiffeieiitiation of the individual cells of the odontogenic 

 epithelium are not disturbed. 



It is apparent that a lack of modeling in the maxilla and mandible 

 not onh aborts the eruption of teeth, but leads to formation of odon- 

 tome-like structures. 



The reason for the failure of ia bone to undergo resorption is as 

 yet unclear. It has been shown that ( 1 ) the ia bone does undergo 

 resorption, but this process is slow and delayed (Bhaskar et ah, 

 1950); (2) the ia skeleton does have osteoclasts (Bhaskar et ah, 

 1956) (Fig. 9); (3) high dosage of parathyroid hormone promotes 



Fig. 9. Bone of ia rat with ostt'otlasts 



750) 



bone resorption and eruption of ia teeth (Bhaskar et ah, 1952); (4) 

 the ia bones are hypercalcified (Kenny et al., 1958); (5) the ia de- 

 fect is not due to hypoparathvroidism (Kenny et al., 1958). 



In view of the above findings and in the light of our present 

 knowledge concerning bone resorption, it would appear that hypo- 



