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S. N. BIIASKAR 



phase, the tooth germ enlarges and the bone tissue of the crypt 

 undergoes rapid bone resorption (Fig. 3). Since the growth of the 

 tooth germs is eccentric and varies from tooth to tooth, the intensity 

 of resorption on the wall of the bony crypt varies markedly in differ- 

 ent crypts as well as in different areas of the same crypt. During 

 this phase bone resorption on the crypt wall is striking, but the 

 epithelial tooth germ does not come into contact with bone tissue. 

 It is separated from it by a zone of highly cellular mesenchvme 





-i»£S***-^****" 



Fig. 3. Osteoclastic resorption of the wall of a bony crypt opposite the 

 epithelial (top) tooth germ. (X 80.) 



which in some areas ( usuallv apical ) contains a great deal of inter- 

 cellular fluid (Fig. 4). 



Movement Out of the Jaws 



After the tooth germ has reached a certain size (completion of 

 the anatomic crown ) , it begins a pronounced movement toward the 

 oral cavity. The mechanism of this outward migration is not fully 

 known, but the movement is accompanied by rapid bone formation 

 on the wall of the crypt (Fig. 5). As in the earlier resorptive phase, 

 the rate of bone apposition varies in different crypts, in different 

 areas of the same crypt, and at different periods of this phase. 

 During periods of rapid growth the apposition occurs as widely 



