THE PHYSICAL EXAMINATION 23 



sils. Decayed teeth are often very important 

 factors. 



All but the last two faults have generally the 

 same cause: that is, some nasal obstruction that 

 encourages or brings on mouth-breathing. As 

 has been said, the most usual cause of nasal 

 obstruction is the adenoid, and the adenoid may 

 bring on the appearance of one or more of these 

 faults. 



If it is difficult to breathe through the nose, 

 then naturally a child — or anyone else — will 

 breathe through the mouth. When this becomes 

 habitual with a growing child, the roof of the 

 mouth often arches abnormally upward, bringing 

 the sides of the jaw together so that the jaw 

 itself becomes V-shaped. This in turn causes the 

 teeth to overlap, because there is not room enough 

 for them to place themselves normally. Because 

 the lower jaw hangs open, it becomes weak, and 

 sometimes becomes unnaturally small, or actually 

 recedes. 



All this brings on other bad effects. For 

 instance, because the jaws do not meet normally, 

 when brought together, the food is insufficiently 

 masticated, and thence may come both chronic 

 indigestion and constipation. 



When the mouth presents the appearance 

 as described, and when, in addition, the nose is 

 also of the adenoid type, then we can feel fairly 



