The Parents' Review

A Monthly Magazine of Home-Training and Culture

Children's Teeth. *

Why is it, that people so frequently say to me, "Well! I think the teeth are a nuisance from the cradle to the grave." In the first place, I think it is because, having but two eyes, and two ears, we have been provided with thirty-two teeth, and the popular opinion seems to be, that half-a-dozen or more can well be spared, without much harm resulting, forgetting that nature wastes nothing, and we may be quite certain, that if twenty or twenty-five teeth could have properly performed the function of mastication, we should not have been provided with thirty-two. Then again, many do not realize that much of the discomfort and pain, arising from the teeth, is due to their own neglect of those organs. No organ of the body can with impunity be neglected or abused, and the frequently neglected and much abused teeth retaliate on their possessors. Again, the importance of the function the teeth perform is not generally recognized, the first thing to be done when we take food is to properly masticate it, crush it thoroughly and mix it with the salivary secretions in the mouth, thus preparing it for digestion.

I have divided this subject into three parts and shall try and say something to you about--

(1) The structure of the teeth.
(2) The cause of caries or decay in teeth.
(3) The prevention of decay, especially in children's teeth.

And first I take the structure of the teeth, as without some knowledge of their structure, it would be impossible for you to understand how those things which cause decay act upon them and break down their structure.

If you take a longitudinal section of an incisor tooth, and place it under a microscope, you will see something similar to what is represented in this diagram. On the outside is the enamel, the hardest substance in the body; it contains no organic matter, and consists principally of phosphate and it is therefore absolutely insensitive.

[The article did not include a diagram; it was probably displayed during the lecture.]

Beneath the enamel we come to the dentine, this forms the body of the tooth and consists, like the enamel, chiefly of phosphate and fluoride of lime, but contains 28% of organic matter. A point of especial interest to us is, that running through the substance of the dentine are numbers of minute tubes, each containing a delicate fibril, which proceeds from the tooth pulp, through the dentine, and terminates immediately beneath the enamel, dentine therefore is sensitive, and you are now in a position to understand how it is, that as a rule (there are no exceptions), so long as the enamel of a tooth remains intact you have no pain in that tooth, but when decay has pierced the enamel and entered the sensitive dentine, that tooth will become sensitive to thermal changes, and probably prevent your enjoyment of the usual cup of hot afternoon tea.

The root of the tooth is covered by a substance called cementum, the structure of which is similar to that of bone. In the centre of the tooth is the tooth pulp (popularly called the nerve), consisting of a gelatinous matrix containing numerous minute blood vessels and nerves; this is one source of nutrition for the tooth, but there is another. Surrounding the root of the tooth in the living subject is a delicate membrane, richly supplied with blood vessels and nerves, and attached firmly to the cementum of the root on one side, and to the bony socket on the other, so that the root of the tooth is not directly attached to its bony socket, but is firmly connected with it by this intervening membrane.

At this point I should like to answer a question which is so frequently asked me. Some one will say, "You have killed the nerve on that tooth, shall I ever have pain in it again?" I sincerely wish I could answer no decidedly, but from what I have just said you will see that although, after the destruction of the pulp, the danger of toothache from decay of the tooth has been averted, there still remains this delicate membrane around the root, which may give you trouble, though the fact remains that a tooth, the pulp of which has been destroyed, and the root properly treated and filled, will probably do good service for many years.

The Causes of Caries.--I am frequently asked the question, Why do teeth decay? What is the cause of decay of the teeth? In medical books it is usual to treat the causes of disease under two heads. (1st) Predisposing causes, or those causes which render the body, or certain parts of the body, peculiarly liable to certain forms of disease, and (2nd) exciting causes, or those which actively produce disease.

The predisposing causes of decay of teeth may be enumerated as follows:--

(1st) Inherent structural defects in the enamel and dentine, imperfectly calcified patches occurring, places in which the lime salts are deficient in quantity, rendering the enamel comparatively soft at these points, and consequently in a condition to be more readily acted upon by acids.

(2nd) All conditions of health accompanied by vitiation of the saliva. (Indigestion is prominent amongst these.) Of course this covers a great deal of ground, almost every derangement of health affects more or less the condition of the saliva, the most severe conditions are associated with the zymotic fevers, such as small pox and typhoid; during these diseases the secretion of the saliva is scanty, and the teeth remain perhaps for weeks, coated with accumulations of epithelial scales and other foul secretions, and unfortunately are usually neglected during these illnesses, when in fact they require the most attention.

(3rd) Crowding and irregularity of the teeth, the teeth being twisted and lapped over each other in such a way as to form resting places where particles of food may lie and ferment, forming acids.

The exciting or active causes of caries are (1) Acids (particularly lactic acid), (2) Micro organisms. The acid having dissolved the lime salts, bacteria immediately invade the tubuli of the dentine, in which organic matter is contained, and then by the action of acids on the lime salts, and of bacteria on the organic matter, the whole structure is destroyed.

And now, having briefly considered the structure of the teeth, and the causes of decay in them, you will of course ask me the question, How can this decay be prevented or arrested? and as parents will especially desire to know, what can be done to preserve the teeth of the children.

It is only quite recently that parents have at all realized the need for keeping the mouth of children in a healthy condition in order to prevent decay of the teeth; and even now the frequent reply to the question, "Is this child taught to clean its teeth?" is "Oh! I did not know the first teeth needed cleaning."

The careful cleansing of the child's mouth should commence practically from the time of its birth. The trained nurse of today regularly cleanses the babe's mouth, with a piece of clean linen rag dipped in boracic solution, thus avoiding Thrush, a disease that most infants suffered from in the days of Mrs. Gamp [from Dicken's Martin Chuzzlewit]. This daily cleansing should be continued by the mother, or whoever takes charge of the child, until it is about two years old, when it should be taught to use a toothbrush. At first water alone may be used with the brush, but when the child has learnt to spit the water out instead of swallowing it, the brush may, previous to use, be rubbed on a piece of pure Castile soap; later on precipitated chalk may be added.

The healthy child is never still; watch him, and you see arms, legs, head, body, constantly on the move during his waking hours, trying the strength of his muscles and developing them; the muscles of the jaw also come in for their share of exercise, and as soon as the child has teeth, you find him nibbling everything he can lay his hands on. This natural habit ought to be encouraged, by giving the child hard biscuits at suitable times, with other foods that require masticating, thus assisting the development of the jaws, and by the friction of mastication, helping to keep the surfaces of the teeth clean. It is important to insist on the teeth being regularly cleansed at bed time, otherwise they will be habitually left, covered with particles of food, for at least eight hours out of the twenty-four, and there will be the danger of acids forming, as the result of fermentation of the said particles.

A tooth-pick (preferably a quill), or better still a piece of waxed floss silk should be passed between the teeth before using the brush, thus making sure that every surface of the teeth is thoroughly cleansed. I know that this systematic treatment is voted a bore by most people; they will tell you that "life is not long enough," "they have not time," &c., which simply means that they do not value their teeth sufficiently to give them the necessary five minutes attention night and morning; small wonder then that the children's teeth are frequently neglected. I am glad to hear that in some of the boarding schools of the present day the master or mistress makes it his or her business to see that the children do regularly attend to their teeth; this is very necessary, because children are naturally careless and forgetful, and unless looked after, are very likely to forget and gradually to neglect this part of their toilet altogether. People sometimes ask, "Why should we bother about the temporary teeth? they only last a few years and are then replaced by the permanent ones," to which I reply:--

(1st) The temporary teeth perform the function of mastication during the most important years of a child's life.

(2nd) A decayed temporary tooth may cause a poor child exquisite pain. The nervous system in children is very irritable, and both headache and earache may be due to, and kept up by, a carious tooth.

(3rd) carious teeth react upon the digestive system by preventing proper mastication of the food.

(4th) The mouth which, as the portal through which the food enters the body, should receive the most scrupulous attention, is rendered unhealthy by the presence of decayed teeth. A parent will sometimes bring a child to me about eight years' old, and on examining the mouth I perhaps find the front teeth in perfect order, but right at the back I see four large teeth, at least one of which, and sometimes all four are more or less decayed; these are the first permanent molars. I point them out to the mother, and with a look of surprise she says, "Yes, I knew those were decaying, but I thought they were first teeth, and would soon be lost." It is most important to remember that the first of the permanent teeth to be erupted are not preceded by temporary teeth at all, but appear right at the back of the mouth, behind all the temporary teeth, and before any of them have been lost, usually when the child is between six and seven years of age.

The child's mouth should be carefully watched by a competent dentist, between the ages of six and twelve years, for during all this time the temporary teeth are being shed, and the permanent ones erupted, and it is most important on the one hand, that the temporary teeth should be preserved until the proper time for their removal, and on the other hand, that they should not persist too long, as they sometimes will do if not removed.

If a temporary tooth is lost too soon, irregularity of the permanent ones is likely to be caused, by the closing up of the space occupied by the temporary tooth, the succeeding permanent tooth being forced to erupt, either outside or inside the proper line. If, on the other hand, a temporary tooth be allowed to persist too long, it will itself prevent the permanent tooth from coming down into its place, and force it to erupt either outside or inside the proper line.

I think, perhaps, it will interest you to know the dates when the teeth should be erupted.

Temporary Teeth:--Lower central incisors, six months; upper centrals, followed closely by the laterals, eight to ten months; lower laterals, twelve months; 1st molars, thirteen to fifteen months; cuspids or canines, eighteen to twenty months; 2nd molars, two years.

Permanent Teeth:--1st molars, sixth to seventh years; central incisors, seventh to eighth years; lateral, eighth year, 1st bicuspids, ninth year; 2nd bicuspids, tenth year; canines, eleventh year; 2nd molars, twelfth to thirteenth years; wisdoms or 3rd molars, any time after seventeenth year.

* Lecture delivered before the Scarborough Branch of the P.N.E.U.

Typed by happi, Mar 2020 Proofread by LNL, Apr 2020