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THE POPULAR SCIENCE MONTHLY 



themselves and their arrangement are the pattern from which the jaw 

 takes its shape. The teeth in different skulls differ so much, that it is 

 extremely difficult, if not impossible, to " match " a missing tooth in 

 one jaw with a tooth from any other one. The natural teeth then 

 have an individuality in keeping with each particular face, and when 

 they are in good condition and in their proper position, can not but 

 add to the beauty, dignity and symmetry of the face. Three people 

 out of four seem to lack in the proper development of the lower part of 

 the face by reason of defective and misplaced teeth, and weak and ill- 

 developed jaws. Hence we see that the " man of destiny," " the man 

 with firm jaw, who knows his own mind," is presumably one who was 

 made to chew properly in childhood, and was not allowed to wash down 

 his food half chewed, or unchewed by gulps of liquid. 



Before. 



After. 



It is not true, that the teeth must fit into the jaws; the reverse is 

 true, the jaws form themselves around the teeth. The bone grows 

 around the roots of the teeth and forms a socket like the mortar or 

 cement around the bricks in a fire-place. This is easily demonstrated ; 

 a tooth, for example, can be completely turned round or moved from 

 one place to another, and, as we say, it grows " fast." For that matter, 

 teeth, as is well known, can be extracted, cleaned and put back again, 

 or teeth from one person's mouth can be put into the place of an 

 extracted tooth in another's mouth and become firmly imbedded and 

 do good service for years. The part of the jaw-bone that embraces the 

 roots of the teeth is called the alveolar process, and it continues to grow 

 and harden for some time after the teeth have been erupted, or after 



