ERUPTION OF THE PERMANENT TEETH 131 



The lateral premolars. The lateral premolars begin to erupt 

 in some individuals at the age of 8 years, and they are all through 

 the gums in all individuals at the age of 16 years. There is very 

 little difference in time of eruption on the two sides of the mouth, 

 especially of the lower lateral premolars, although the left upper 

 erupts earlier than the right upper. The order of eruption is as 

 follows: (1) left upper; (2) right upper; (3) right lower, and (4) 

 left lower. The upper lateral premolars erupt less than a year 

 earlier than the lower. 



The lateral premolars erupt first in the Filipinos, and second 

 in the Germans and Americans, at almost the same time for each 

 of the latter. The lateral premolars erupt earlier in the girls 

 than in the boys. 



The first molars. The first molars begin to erupt in some 

 individuals before the age of five years, and nearly all, if not all, 

 the first molars are erupted in all individuals at the age of 12 

 years. 



There is practically no difference in the time of eruption of 

 the first molars on the two sides of the mouth, but the lower first 

 molars erupt slightly earlier than the upper, therefore the order 

 of eruption is (1) and (2), lower first molars, (3) and (4), 

 upper first molars. The lower first molars erupt earlier than the 

 upper, the interval being considerably less than a year. The 

 first molars erupt later in the Filipinos than in the Germans or 

 Americans who are almost exactly alike in the time of eruption of 

 these teeth. 



The first molars erupt about one year earlier in the girls of 

 each group than in the boys. 



The second molars. The second molars begin to erupt at about 

 the age of 10 years — slightly earlier in the Filipinos — ^and their 

 eruption is completed in all, or nearly all, the individuals at the 

 age of 16. 



There is practically no difference in the time of eruption of 

 the second molars on the two sides of the mouth, but the lower 

 second molars erupt about a year earlier than the upper, therefore 

 the order of eruption is (1) and (2) lower second molars, and (3) 

 and (4) upper second molars. The second molars erupt earlier 



