( Originally Published 1936 )
WHAT CAUSES BAD ODORS ON BREATH—HALITOSIS
THERE is no such thing as a little garlic," is a tried and true doctrine that Drs. H. W. Haggard and L. A. Greenberg of Yale have been engaged in refuting. There is such a thing as 0.00015 milli-grams of the essential oil of garlic which can be detected by chemical analysis of the breath, and that amount can also be detected by the sense of smell. The nose knows.
Odors on the breath may come theoretically (1) from the air breathed out from the lungs: the substances might be absorbed into the blood, the blood carrying them to the lungs, where they are dumped into the expired air; or (2) by the same process they appear in the saliva; or (3) the stomach is the reservoir, the odor passing up the esophagus, or (4) from particles of the odorous substance remaining in the teeth or on the rough surface of the tongue.
Drs. Haggard and Greenberg have proved pretty conclusively that the last modus is the one most often operating. They used the classic offenders—onion and garlic. (Chemically, if you would like to know, they are, respectively, allyl-propyl disulphide and allyl disulphide. "How was George today?" "He reeked of allyl-propyl disulphide.") They devised a method of recognizing these on the breath. After eating 1.5 gm. of garlic the amount of allyl disulphide on the breath was:
In five minutes, 0.0028 milligrams; in one hour, 0.0008 milligrams; in four hours, 0.0003 milligrams; in six hours, 0.0002 milligrams.
ODOR NOT FROM STOMACH
For those who believe that bad breath comes from the stomach, the following experiment should be convincing to the contrary: when the garlic was chopped up, put in gelatin capsules and swallowed, no odor whatever was detected on the breath during the next twenty-four hours. "The only exception occurred when during the first three hours after eating the garlic, the subject belched: only momentarily then was the breath rendered foul by the odor from the stomach."
The conclusion seems certain that bad breath in most cases comes from particles left in the mouth cavity--in teeth or on tongue. This is further proved because the odor of onion or garlic can be removed by the use of chloramine. Chloramine is a standard U.S.P. product which any drug store should supply. After the mouth has been rinsed, the teeth brushed and the tongue scrubbed with a solution made by dissolving five grains of chloramine in a quarter of a glass of water, no odor of garlic could be detected on the breath. Nor could any garlic oil be found on chemical analysis, which proves that the chloramine does not simply mask the odor, but actually destroys the oil.
These are almost the first really scientific investigations of that pressing subject of halitosis. Bad breath may come from nose disease, atrophic rhinitis. But by far the larger number of ordinary cases that your best friend won't tell you about, are due to odorous particles left in the teeth or on the tongue.
TOOTH DECAY-DENTAL CARIES
Dental caries, or dental decay, or the formation of dental cavities, has been considered up to within a few years ago due exclusively to the lodgement of bacteria on food particles on the teeth, and the destruction by the bacteria of the superficial enamel. This theory, while it cannot be entirely abandoned, certainly is not the whole story, and recent work has shown that destruction of teeth is partly a nutritional process.
Let us examine the nature of dental caries. To do so the anatomy of the teeth must be understood. A tooth consists of three layers, or structures. The outer layer, the enamel, is the hardest tissue in the body and, therefore, furnishes an extremely strong defensive wall. Underneath it is the dentine which, while it is fairly hard and contains calcium, yields very rapidly to decay as soon as it is attacked. Underneath the dentine is the third layer, the pulp, which puts up no resistance to infection whatever.
Plainly, tooth infection begins by the breaking down of the protective wall of the tooth—the enamel. This enamel contains 95 per cent of calcium or lime salts, and caries of the enamel appears to be a solution of these lime salts. It is generally supposed that the dissolving of enamel is done by acid produced by the action of bacteria on food particles. Objections to this theory are that all mouths contain germs which are capable of doing this, and yet all mouths do not have dental caries. Also that the caries begins in small spots, whereas one would suppose that if it were due to the action of bacteria on food, it would attack rather large areas of the enamel.
Decalcification of the enamel, or the beginning of caries, can be seen as small white spots on the surface of the tooth. It is now supposed that this decalcification—and the theory is backed by strong experimental evidence—is due to nutritional defects from improper diet.
In experiments made at Mooseheart on over 300 children, the conclusion was that pyorrhea and dental caries can occur in children who are receiving a quart of milk, one and one-half ounces of butter, a pound of vegetables, half a pound of fruit and nearly one egg a day. These foods do not, therefore, contain substances that prevent the diseases mentioned. The addition of a pint of orange juice and the juice of one lemon to a diet that is adequate in all other respects, supplies something that leads to a disappearance of these diseases in a majority of the cases.
These experiments, it seems to me, are not sufficiently confirmed to allow us to say that the older theory of external infection has nothing to do with the case. Brushing the teeth regularly and cleansing the mouth and spaces between the teeth is still as important as it ever was.
DENTIST WRITES OWN VIEWS ON BEST CARE OF TEETH
A prominent New York dentist has objected to an article recently published by this writer, which was entitled "Candy Wins Approval."
In the article I stated that the old idea that candy contributed to tooth decay had been explained by modern medical research on the basis that if children ate candy they would not eat enough fruits and vegetables which give them proper minerals to build teeth, and that, therefore, any child who ate candy should also eat some fruits and vegetables.
This suggestion of mine was based upon considerable research in various laboratories, and sufficiently authoritative that Dr. Frederick F. Tisdall of Toronto stated it before the American Academy of Periodontology. However, I am very glad, for the sake of fairness, to print the view of the matter which the New York dentist holds, as follows :
"Reliable investigators on the causes of tooth decay have not yet denied the theories of Miller. These still are the best we have. While some day they may seem gross and lack detail, nevertheless, it is indisputable that definite factors do bring about tooth decay, and these generate from food debris lying on the teeth in places where it is not easily removed.
"Tooth structure is the soil in which decay occurs. If the tooth structures are poor, lack phosphorus and calcium, they furnish good soil for tooth decay. If the structures are good, rich in phosphorus and calcium, then they are poor soil for decay.
"Again, there probably are dissolving or buffing substances in the saliva, or perhaps even phosphorus and calcium, which find their way into the enamel. But this again is like rain falling on the soil and generating the seeds. The rain (the saliva) lacking these protecting substances, permits decay to proceed.
"It is quite true that numerous articles, in substance, much the same as your newspaper article, are appearing in our scientific journals. These are given as matters of opinion, and open to discussion.
"Cleanliness of the mouth is of the greatest value in preventing tooth decay. Let us not set it aside until we have established some-thing better."
I am inclined to agree with this letter, and I do not believe that my article was very far out of line with it. I do not believe that the doctor intends to take all candy away from children any more than I intended that they should eat as much of it as they wanted to.
WHY SIX-YEAR-OLD MOLARS ARE MOST IMPORTANT TEETH
The most important teeth in the mouth are the first molars. There are four of them—two in each upper jaw and two in each lower jaw.
They are the most important teeth because they are the first permanent teeth to appear. Being the first permanent teeth, they serve as bumpers for all the other teeth which come in.
They are the most important teeth because they are permanent teeth, and being the first permanent teeth are particularly liable to decay. They have deeper grooves than the baby teeth. Food particles getting into these grooves remain and putrefy, and unless the nutrition of the tooth is very good, decay will set in.
They are the most important teeth because almost universally they are regarded as part of the baby set, and when they begin to decay no attempt is made to preserve them, and thus they are destroyed and the mouth loses some of its most valuable architectural keystones.
Look for these teeth in your child. They begin to come through the gums at the age of six years—that is, about two or three years after the last of the temporary teeth. The hindermost temporary teeth are also molars; that is, they have large grinding surfaces, and this newcomer looks, at first, exactly like them. It is generally believed, more or less instinctively by most people, including young parents, that the first permanent teeth will be front teeth because the first temporary teeth are the front teeth. This, however, is not true.
Be sure to watch for these first permanent teeth, the six-year molars. Be sure that the child keeps them clean. Be sure that they are filled and attended to by the dentist at the first sign of decay. Be sure that at this period the child gets enough fruit and vegetables and milk—substances which strengthen the teeth against decay.
Don't allow the first permanent tooth to be a sweet tooth.
When your child eats some candy, be sure he eats some fruit also.