SECOND PERIOD. 



LEVELING, PROGRESSIVE USE, AND FALLING OUT OF THE INCISORS 

 OF FIRST DENTITION. 



About One Year. — The corner teeth have protruded from 

 the gums, but the inferior ones are not yet in contact with the 

 superior teeth. The inferior pinchers, if not leveled, are at least 

 very much used on both their borders. The incisive arch com- 

 mences to be a little depressed in the centre. The superior pinchers 

 and intermediate teeth just commence to wear at their posterior 

 borders. (Figs. 53, 54, 55.) 



About Sixteen Months. — The superior corner teeth meet the 

 inferior and commence to wear at their anterior border ; the 

 necks are clear of the gums. Often at this time the inferior 

 pinchers are leveled, but the intermediate teeth are rarely more 

 than slightly worn. The incisive arch is flattened in front. 

 (Figs. 56, 57, 58.) 



About Twenty Months. — The inferior corner teeth are nearly 

 leveled; the superior ones are less so. The inferior pinchers 

 stand out from the gums, and the intermediate teeth are often 

 leveled. The incisive arch becomes less convex. (Figs. 59, 

 60, 61.) 



About TiDO Years. — The inferior dental arch is completely 

 leveled at the pinchers and intermediate teeth, and the superior 

 arch is nearly so. The superior pinchers stand out from the 

 gums, and behind them is found a moderately sensitive swelling, 

 — due to the permanent teeth, which are pressing on the gum of 

 the palatine arch. The intermediate teeth are free from the 

 gums above and below. The incisive arch has widened from 

 side to side and the pinchers and intermediate teeth form almost 

 a straight line. (Figs. 62, 63, 64.) 

 (64) 



