44 



MASS. EXPERIMENT STATION BULLETIN 310 



is no consistent difference in the incidence of new caries at the various levels of 

 the condition of the teeth. The children who received both milk and tomato 

 made no better showing than those receiving milk alone, nor is the slight difference 

 between the experimental and control groups enough to be significant. 



Table 15. — Me.'^n Percentage of Teeth at the June Examination in Which 



Caries or Pits and Fissures Had Developed Since the September 



Examination, as Affected by Mid-morning Feeding 



Condition of 

 Teeth in 

 September 



Number 



of 

 Children 



Teeth per Child in June 

 Percentage 



Number 



With New With New 

 Caries Pits and 

 Fissures 



Evaporated Milk 



Excellent 30 27 1 



Good 115 23.3 



Fair 65 22.8 



Poor 16 23.1 



Very Poor 5 23.2 



Total '. 2.37 23.7 



Evaporated Milk and Tomato 



Excellent 14 2(>.0 



Good 70 24.2 



Fair 41 23.7 



Poor 7 23.0 



Very Poor 3 22 . 



Total 135 24.1 



All Receiving Lunch 



Excellent .50 20.8 



Good 185 23.0 



Fair 106 23.1 



Poor 23 23.1 



Very Poor 8 22 . 8 



Total 372 23.9 



No Lunch — Controls 



Excellent 27 24.4 



Good 69 24.4 



Fair 44 22.6 



Poor 10 21.7 



Very Poor 5 23,4 



Total 161 23.6 



Some observers (5) have contended that, as the teeth themselves vary in sus- 

 ceptibility, a more accurate statistical analysis may be made by comparing one 

 type of teeth and that the first permanent or six-year molars are the best adapted 

 for observation with children of this age. Such an analysis has been made and 

 is summarized in Table 16. Again, beneficial effects of the feeding were not 

 apparent. The same was true when the general condition of the teeth and gums 

 (gingivae) was considered (Table 17). The percentage of children who showed 

 improvement and the percentage who were in poorer condition at the end of the 

 year were practically the same in the experimental and in the control groups. 



No improvement in the condition of the teeth of children as a result of the 

 mid-morning feeding either of evaporated milk or of evaporated milk and tomato 

 is indicated by these data. It may be, of course, that the methods which it 



