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A MANUAL OF DENTAL ANATOMY. 



The dates of the eruption of the milk teeth vary much, 

 no two authors giving them alike ; but the whole of the 

 deciduous teeth are usually cut by the completion of the 

 second year. Cases in which incisors have been erupted 

 before birth are not very uncommon. At a time when the 

 crowns of all the deciduous teeth have been fully erupted, 

 their roots are still incomplete, and are widely open at their 

 bases, so that it is not till between the fourth and sixth 

 years that the temporary set of teeth can be called abso- 

 lutely complete. \/ 



At the sixth year, preparatory to the appearance of any 



of the permanent teeth, the temporary teeth may be observed 

 to be slightly separated from each other ; they have come to 

 occupy a more anterior position, pushed forward, it may be, 

 by the great increase in size of the crypt of the permanent 

 teeth behind them. The general relation of these to the 



( J ) Normal well-formed jaws, from which the alveolar plate has been in 

 great part removed, so as to expose the developing permanent teeth in 

 their crypts in the jaws. 



