their brothers' teeth. There
could be no better first lesson than to ask each pupil to look in a
hand mirror and to count each tooth obviously needing a cleaning or a
filling. The most urgent need can thus be ascertained without expert
aid. But because parent, teacher, or child cannot discover defects does
not prove that dental care is not imperative; hence the importance of
examination by a dentist or by a physician competent to discover dental
needs. If a private, public, or parochial school has no paid visiting
dentist, a zealous school officer can, at least in large towns,
persuade one or more dentists or physicians to make a few first tests
to confirm the teacher's findings, and to persuade the community that
regular examination and reexamination are necessary and a saving of
pain, beauty, and money.

Reexamination is necessary because decay _may_ start the day after a
dentist has pronounced a tooth sound. For most of us twice a year is
often enough. A reexamination should be made upon the slightest
suspicion of decay, breaking, or loosening.

Educational use should be made by the teacher of the results of school
examination. Children cannot be made self-conscious and cleanly by
telling them that their teeth will ache three or five years from now.
They can be made to brush or wash their teeth every morning and every
night if they once realize that cavities can be caused only by _mouth
garbage_. All decay of human teeth starts from the outside through the
enamel that covers the soft bone of the tooth. This enamel can be
destroyed by accidentally cracking or breaking it, or by acids eating
into it. These acids come from (1) particles of food allowed to remain
in the teeth; (2) tartar, etc., that adheres to the teeth and can be
removed only by a dentist; (3) saliva brought up from an
ill-conditioned stomach. Even where the enamel is destroyed, absolute
cleanliness will prevent serious decay of the tooth. A perfectly clean
tooth will not decay. Generally speaking, unless particles of food or
removable acids remain on or between the teeth long enough to
decompose, teeth cannot decay. Decay always means, therefore,
uncleanliness. To unclean teeth is due in large part the offensive odor
of many schoolrooms.

Uncleanliness becomes noticeable to our neighbors sooner or later.
There is no offense we are so reluctant to commit as that of having
uncleanliness of our bodies disagreeable to those about us. Very young
childr