TEETH 



5729 



TEETH 



During the life of a tooth a soft pulp, con- 

 taining nerves and blood vessels, fills a cavity 

 known as the root canal, which extends through 

 crown and root. Immediately surrounding the 

 cavity, and making up the greater part of the 

 bulk of the tooth, is a hard, bony, yet elastic, 

 substance called dentine. This 'is covered on 

 the crown with enamel, a tissue so hard that it 

 will strike fire with flint. The root of the tooth 

 is fixed in place by a thin layer of bone known 

 as cementum, and at its tip is a narrow aper- 

 ture through which the blood vessels and nerves 

 of the pulp cavity enter. Exposure to the air 

 of these delicate nerves, through decay of the 

 outer parts of the tooth, is responsible for the 

 agonies of toothache. 



Care of the Teeth. Because the inside of the 

 mouth is always moist and warm it is a very 

 favorable breeding place for germs of all kinds. 

 A neglected mouth may harbor organisms that 

 cause diphtheria, pneumonia and other infec- 

 tious diseases. Furthermore, accumulations of 

 food particles, collecting in the spaces between 

 the teeth, at the margin of the gums and else- 

 where, encourage the multiplication of count- 

 less bacteria which form acids on exposed sur- 

 faces of the teeth. These acids eat into the 

 protecting enamel, and if no steps are taken 

 to prevent further harm, ultimately cause the 

 teeth to decay. For these reasons the mouth 



FIRST SET OF TEETH 



(a) Central incisors; (&) lateral incisors; (c) 

 cuspids; (d,e) temporary molars ; (/) sixth-year 

 molars. 



and teeth should be scrupulously cared for 

 from infancy to the end of life. Parents who 

 think the temporary teeth need no attention 

 are badly in error. The first teeth of the small 

 infant should be cleaned at least twice a day 

 with a soft brush, and just as soon as the child 

 is old enough to handle a brush he should be 

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taught to perform this hygienic act for himself. 

 Neglected teeth in the mouth of a little child 

 are a source of physical pain and a detriment 

 to thorough chewing and to the general health, 

 and they have an adverse effect on the teeth 

 which come later. 



Not only should the teeth be thoroughly 

 scrubbed, but the gums and back of the tongue 

 a a 



PERMANENT SET OF TEETH 

 (a) Central incisors; (6) lateral incisors; (c) 

 cuspids; (d, e) bicuspids; (/) sixth-year molars; 

 (g) molars. 



also need daily cleansing. In addition to a 

 good, moderately-stiff brush one should have 

 in the toilet equipment a reliable tooth paste 

 or powder and an antiseptic mouth wash. Ad- 

 vice on these matters is always cheerfully fur- 

 nished by the family dentist, who should be 

 visited at least twice a year by each member 

 of the family. The custom of brushing the 

 teeth sidewise has fallen into disfavor, as this 

 method lacks thoroughness. Instead, the brush 

 should be placed upon the gum and be manipu- 

 lated with a rotary movement upward on the 

 lower teeth and downward on the upper. The 

 teeth should be cleaned on the inside and out, 

 and back to the last molars, and the mouth be 

 rinsed by forcing water between the teeth. In 

 addition, after each meal (but away from the 

 table) the crevices of the teeth should be 

 cleaned with a quill toothpick and dental floss. 

 If possible, a brushing should be given after 

 each meal, but under no circumstances should 

 one omit it at night before retiring. If such 

 precautions are taken, and the teeth are cleaned 

 and examined twice a year by a reliable dentist, 

 decay of these important organs can usually be 

 prevented, or at least materially checked. 



Aside from neglect of the mouth, unhygienic 

 habits of eating may affect the teeth. The cus- 

 tom of bolting the food, or of including too 

 great a proportion of soft and partly-digested 

 foods in the diet, interferes with that vigorous 



