ERUPTION OF THE PERMANENT TEETH 129 



nearly if not all through the gums at the age of 10 years. There 

 is practically no difference in the time of eruption on the two 

 sides, but the lower median incisors erupt about a year earlier 

 than the upper, a little less than a year on the left side and a 

 little more than a year on the right side. 



The median incisors erupt in the following order: (1) lower 

 right; (2) lower left; (3) upper left; (4) upper right. The left 

 upper median incisors erupt at approximately the same time in 

 the Germans and Americans, the left lower erupt earlier in the 

 Americans than in the Germans, and the right upper erupt earlier 

 in the Americans than in the Germans, although the German 

 girls may be slightly more precocious than the American girls. 

 The median incisors erupt earlier in the Filipinos than in either 

 the Germans or Americans. The median incisors erupt earlier 

 in the German and American girls than in the German and 

 American boys. 



The lateral incisors. The lateral incisors begin to erupt in 

 some individuals as early as the age of 6 years, and the teeth 

 are nearly if not all through the gums at the age of 13 years. 

 There is practically no difference in the time of eruption on the 

 two sides, but the lower lateral incisors erupt about a year 

 earlier than the upper, a little less, than a year on the left side 

 and a little more than a year on the right side. 



The lateral incisors erupt in the following order: (1) lower 

 right; (2) lower left; (3) upper left; (4) upper right. The lateral 

 incisors erupt earlier in the girls than in the boys. The lateral 

 incisors erupt earlier in the Filipinos than in the Germans and 

 Americans, although there is very little difference in time for the 

 eruption of the lower teeth of this type. 



There is so little difference in time of eruption between the 

 Germans and Americans that they may be considered as having 

 the lateral incisors erupted at the same time, but the slight 

 difference indicates that the Germans are more backward than 

 the Americans. 



The canines. The canines begin to erupt in some individuals 

 as early as the age of 8 years, and the teeth are nearly all, if not 

 all, through the gums at the age of 15 years. There is practically 



THE AMERICAN JOURNAL OF ANATOMY, VOL. 17, NO. 1 



