SCHOOL HYGIENE 



435 



remedied, and thus the children are made happier and better 

 able to do their work. The results of the examinations of 

 hundreds of thousands of children in all parts of the United 

 States are shown in the following table in the first two col- 

 umns. The last column is obtained by estimate through 

 multiplying the number of school children in the United 

 States (about twenty million) by the per cents obtained 

 from those children who have been examined. 



TABLE SHOWING DEFECTS OF CHILDREN 



It is found that only about one third of the children are 

 free from defects, about one third have defects of teeth alone, 

 and the remaining third have defects of the teeth and in 

 addition at least one other defect. 



Defective teeth. The most common of all defects are those 

 of the teeth. From two thirds to three fourths of all chil- 

 dren are found to have defective teeth. This may include 

 every stage from a small decaying spot to teeth which are 

 almost entirely decayed. Of all teeth examined about one 

 fifth are defective. 



How defective teeth affect health. Defective teeth may 

 prove injurious to health in three ways : first, the power of 

 mastication of food is decreased; second, the pus from the 

 decaying teeth when absorbed into the blood or taken into 

 the stomach has an injurious effect; and third, decaying 

 teeth may be the breeding place of bacteria that cause 

 disease, such as rheumatism and heart disease. Some very 



