Effect of Food Habits on Tooth Formation and Decay.

New Zealand Journal of Agriculture, Volume 86, Issue 6, 15 June 1953, Page 585

Effect of Food Habits on Tooth Formation and Decay.

By

EVELYN E. MOORE,

Field Officer in

Rural Sociology, Department of Agriculture, Palmerston North

NEW ZEALANDERS, though perhaps justly proud of iheir high standard of living, have little to be proud of when dental health is taken into consideration as one of the criteria of good health. This should be cause for serious thought, yet many remain relatively unwilling to regard it as a problem which should be of concern to every New Zealander. PERHAPS this unconcern is due to the erroneous opinion held widely a generation ago, and undoubtedly still prevalent, that it is easier, cheaper, and even better for the health to substitute artificial teeth . for natural teeth at an early age. In addition, such an attitude instilled consciously or unconsciously in the minds of the children of this generation can ultimately do much to impede the progress made by the School Dental Service and others who work to improve the teeth of New Zealanders. There are many causes of tooth decay, a fact not always appreciated by the average mother, who perhaps corrects or avoids only one of the causes, and then is disappointed or discouraged when her children do not have perfect teeth. In this article will be discussed the various dietary factors which have been shown to affect the teeth. These factors could be divided into two groups: those which help prevent decay, and those which tend to bring it about, or accelerate it, once it has begun. Structure of Teeth To understand the causes of dental caries or tooth decay it is necessary to know something of the structure, growth, and development of teeth, and also of the direct process of decay, which is what is happening to a tooth as the decayed area or hole grows larger and larger. • The structure of a tooth is shown in the diagrams on page 587. In the diagram of a tooth cut lengthwise through the centre (right) the following different substances are seen:— (1) Enamel. (2) Dentine. (3) Cementum. (4) Root canals. (5) Pulp chamber. • Enamel: This covers the surface of the visible part of the tooth and is very hard and dense. It is the most durable substance in the body. It normally protects the tooth from injury and decay. Unfortunately, if this layer is broken or imperfect or eaten away by acid, it cannot be re-formed, and decay is allowed to spread rapidly in the softer layer of dentine underneath. The enamel consists mainly of a complex structure of lime and phosphate. Dentine: This is the thickest layer and gives the tooth its shape and

strength. Although it contains the same minerals as the enamel, it is a much less dense and softer structure. Cementum: This covers the part of the tooth that is below the level of . the gum. It is more like bone in structure than the rest of the tooth, and attached to it are the fibres which hold the tooth firmly in place. Root canals: These are small canals in the roots of the teeth through which run the blood vessels and nerves to the pulp chamber. Pulp chamber: This is the space in the centre of the —known as “the nerve” to the majority of people —and contains the blood vessels and nerves which nourish the tooth and is also the organ from which the dentine of the tooth was formed. Development of Teeth Teeth begin to be formed about 6-J months before a baby is born, and at birth the process is so far advanced that some of the permanent teeth are beginning to be formed. The crown, the part that will eventually be above the gum, develops first, and it will thus be seen how important it is for the expectant mother to ensure that her diet is adequate in all respects. This care should be exercised also during the time the baby is being nursed.

The eruption of the permanent teeth is preceded by a dissolving 1 process in the roots of the baby teeth and the crown of the permanent tooth pushes its way up until with its newly developed root it finally takes the place of the baby tooth. ; , It is important that these baby teeth should be kept until the natural time for losing them, if possible, as their early loss means that the child will not chew its food so well, and may develop an overwhelming preference for soft, sloppy foods, resulting frequently in an unbalanced diet and poor health. Infected baby teeth also undermine the health of the child. There is the additional danger that early loss of baby teeth will let neighbouring teeth encroach on the vacant space and leave insufficient room for the permanent teeth to erupt later, possibly causing crowded, irregular, and crooked teeth, which are more apt to decay than sound well-spaced straight teeth.

The first four permanent . molars (or back teeth) come through when the child is about 6 years old. These may sometimes be mistaken by parents for baby teeth and be neglected, resulting, perhaps, in irreparable damage to the teeth.

Tooth Decay

Tooth decay is so widespread in New Zealand that practically everyone suffers from it at some stage. Primarily it occurs in children and adolescents. In later life new areas of decay usually develop slowly, and, in fact, almost complete immunity may be developed. Decay usually occurs between the teeth below the point of contact, and in pits and fissures on the chewing surfaces. Soft, sugary or starchy foods which lodge in these areas are not easily removed, and, because the mouth, being warm and moist, is an excellent place for growth of bacteria, they develop rapidly in these films of food. Acid is formed which dissolves the minerals in the enamel, which is slowly eaten away. Next the dentine

layer, which is much softer (and more easily eaten away by acid), is reached, and bacteria and food debris accumulate in the cavity formed and more rapid decay occurs. Finally, if the cavity is not filled, the pulp is reached and invaded by bacteria, leading to the formation of an abscess accompanied by acute toothache. This is, of course, only the immediate cause of decay. The indirect causes mainly have a direct or indirect basis in nutrition, which is the nature and quality of the food eaten, and control of these is in the power of everyone, especially every parent who wishes to start children off in life with good natural teeth. Effect of Diet Probably the most important factor in building good teeth, and certainly the . one parents have most control over, is diet. This was shown in many countries during the war, when the teeth of children showed a marked improvement due to the greatly reduced availability of sugary foods, the use of bread made of coarse whole grain or high- extraction flour, and the wise and controlled distribution of milk, oranges, and other nutritious foods to those who needed them most, such as growing children. The body cannot build good teeth without an adequate supply of all the minerals and other nutrients which are required for their development. It is not sufficient only for the mother to provide her growing infant or child with foods containing plenty of these nutrients. Recent research indicates that the diet of the expectant mother plays a very important part in the likelihood of her children having good teeth. In animals, research has indicated that the effect of the mother having a good diet is five times as important as any local effect on the teeth of the young animal. Foods which will ensure that the child or the expectant mother has all the required minerals and vitamins for good bone and tooth growth are milk and milk products, such as cheese, eggs, green and root vegetables, meat, particularly liver, fish, especially fish liver oils, and the fruits richer in minerals and vitamins, such as black currants and other berry fruits, oranges, grapefruit, and tomatoes, and rosehip syrup. The amounts recommended are: — Milk: Children and expectant and nursing mothers, If pints a day; pre-

school children, 1| to If- pints a day; other adults, 1 pint a day. Cheese: A small cube every day. Eggs: One a day when possible. Meat and fish: Serve once a day with liver, and fish, when possible, once a week. Vegetables: One generous serving of each of the following types each day: — (1) Potatoes or kumaras. (2) Green vegetable, cauliflower, or swede. (3) Other vegetables, or an extra serving from the second group. Raw fruit: One each day. Fish liver oil: Pre-school children and expectant and nursing mothers, 1 teaspoonful (or capsule equivalent) each day. In winter and spring it is advisable that older children should also have fish liver oil. Unrefined cereals, wholemeal bread and butter, and iodised salt should also figure in the daily menu. • These foods not only provide the nutrients necessary for sound tooth structure, but, in addition, they build up the general health and resistance to infection and infectious diseases, some of which are suspected of causing temporarily a greater susceptibility to tooth decay. Other Aspects Primitive peoples usually have good teeth in spite of the fact that their diet may not be as good, in its mineral and vitamin content, as that of their civilised neighbours, who may on an average have a far higher rate of dental decay.

This is because the food of primitive peoples is coarse and unrefined generally, and contains far less sugar or cooked, soft, and doughy foods, and, frequently, more meat or fish or coarse fibrous vegetables, and fruits. The effectiveness of a diet of this nature is due to the cleansing action on the teeth and mouth of the foods eaten. These foods also stimulate the flow of saliva, and because they require more chewing, give the jaws more exercise, a factor which has been shown fairly conclusively to result in better and more rounded development of the jawbones, giving the teeth plenty of room to grow without becoming crowded or crooked. It has been estimated that primitive man gave his jaws 10 times as much exercise as his modern

counterpart, so that it is not surprising that many children today have small pointed dental arches, resulting in crowded teeth, or to avoid this have two or more teeth extracted to make room for the others. These factors can be counteracted in the modern diet in the following way:—

Foods which require plenty of chewing such as crusts, apples, raw root vegetables, celery and salad vegetables, and oven-baked bread should be included in every meal and these foods should be eaten at the end of a meal, as they have a cleansing action on the teeth.

A continual flow of normal saliva has an important influence on the health of the teeth, mouth, and gums, as it normally covers the teeth and as decay begins on the enamel surfaces of the teeth. Foods which stimulate a flow of saliva are hard, dry substances such as oven-baked crusts, crisp raw vegetables and fruits, and also acid fruits such as oranges. Acid fruits particularly stimulate the flow of alkaline saliva, which counteracts the acidity of the fruits and is, therefore, also valuable in neutralising or counteracting the acid formed by bacteria on tooth surfaces.

Some foods such as bread and butter, cakes, or biscuits decrease the flow of saliva below the normal resting flow and cause it to be slightly less alkaline. Thus these foods, which, are commonly eaten at the end of a meal, are able to bring about decay in not one way, but in several ways. They cling to the teeth and form a sticky film which is ideal for the development of bacteria capable of causing decay, they reduce the flow of normal cleansing saliva, and they tend to reduce its alkalinity, making it less able to counteract the bacteria-produced acids capable of eating away the tooth enamel.

Two important facts therefore arise. The first is the necessity for a diet containing all the nutrients essential for building sound teeth. The second is the great effect which many foods can have directly on both the causation of tooth decay and the rate at which it progresses.

Thus it is important to see that a child eats few sweets and cakes, but a meal finishing with new bread, butter,- and jam will probably be almost as effective in causing decay as one finished with cakes and sweets, unless the bread, butter, and jam are followed by teeth-cleansing foods such as fruit, raw vegetables, or crisp oven-baked crusts. When possible the teeth should also be cleaned immediately after a meal, and the cleaning must be thorough to be effective.

Effect of Fluorine

There is one other factor, which may be considered as a dietary one, and that is the effect of fluorine, a mineral element low in New Zealand soils and water. Overseas and preliminary New Zealand investigations have indicated that this mineral, properly used, will reduce dental decay by about 40 per cent. It has, however, to be supplied during the years when the teeth are being formed, and as far as can be ascertained has no inhibiting effect on tooth decay in adults who have grown up without it. Its use is being tested in New Zealand at present by dentists,

the School Dental Service, and others qualified to use it effectively. If the tests are successful, it is probable that within a short time New Zealand children will be able to benefit from its use to reduce tooth decay by one or more of the methods being tried out. rrj x irv x t ■' £ aj ix tnect or Diet on leetn ot Adults Once the teeth are formed it seems probable that the most important factors in reducing decay are careful attention to cleaning the teeth and a general avoidance of the type of menu which ends invariably with sweet soft foods, especially when it is impossible to clean the teeth immediately afterward. Cleaning the teeth is an important factor in reduced decay, provided it is done properly; otherwise it is more or less useless. To be effective it should be done immediately after each meal and before going to bed. It is estimated that about 3 minutes are required to clean the teeth thoroughly. To hurry over the task is likely to render the cleansing ineffective and a complete waste of time. A toothbrush of the short-headed variety is the best for both children and adults, Cleaning the teeth immediately on arising probably affords little protection from decay; it is far more effec- ' tive when carried out immediately after breakfast . . . j axx t Morning and Afternoon leas A factor not always considered is that of eating sweets, cakes, and

similar foods between meals. It should be obvious that if it is a regular practice, it is so likely to be a cause of tooth decay. Ammonium lon Powders and Pastes . American experiments indicate that ammonium ion powders and pastes have some protective effect against decay in that country, but experiments carried out in New Zealand have so far not shown conclusively that they are of benefit here, Regular Dental Treatment The importance of regular visits to the dentist, or in the case of children to the school dental nurse, cannot of course be over-emphasised. Regular treatment not only stops decay, but it an improve the durability of badly formed teeth if children are treated early enough. Protective fillings can be placed in fissures in the enamel of badly formed teeth, crooked teeth can be straightened, and teeth can be removed to prevent overcrowded crooked teeth being formed, as such teeth besides being unsightly are much more subject to decay. In the case of adults, and it is adult New Zealanders who are most careless with their teeth, dental care not only helps prevent decay, but is also an insurance against the serious onset of gum diseases such as pyorrhoea, which if allowed to continue unchecked, attack the bony sockets of the teeth, causing the teeth to loosen

and making their extraction necessary, Causes of these gum diseases include unclean, decayed, and crooked teeth, Sdli n fitSi e 2 c S rowss 10 o? t°e f eth m and fhe reSlai• * Snsumntion of Woods regular consumption of sort . tooas which require little or no chewing. Artificial Tooth Ar iTiciai ee ” There are many who argue that it is better to get the teeth out while young because it will be necessary sooner or later anyway, that artificial teeth imnrove the annearance and that leeixi improve me appearance, aua lira artificial teeth are better for the health. These arguments are correct onlv in a few SSances Y First, there is no reason why a good set of natural teeth, treated with care and well looked after, should not last a lifetime. Many members of primitive races reach old age and still have perfect sets of teeth due to choosing unconsciously a diet which contains none or few of the factors apt to cause decay. The Maori, before the coming of the white people, is a good example, Further, many of the causes of decay

and the removal of teeth may be able to be simply controlled as scientific knowledge of this subject increases. Secondly, the argument that artificial teeth look better than natural teeth may also be easily refuted. It may be so fop adults todly who have cro0 y ked> broken, and. badly stained teeth, but there is no reason why children with properly cared for teeth should grow up with crowded, ugly, .or crooked teeth. Causes such as thumb and finger causes i* such as tnump ana ■u ringer king, lip biting, and mouth breathin£f should be looked for and corrected l g s OUi ? »e looxea lor and corrected toTlong'relentloS of baby teeth are avoided by regular dental care. Less obvious causes such as illness, lack of foods providing sufficient chewing exercise, and a diet containing inadequate nutrients for good bone and teeth growth can be avoided or lessened, by the attention of parents to providing their children with a healthful, well-balanced diet, which would also help build up resistance to disease. It has also been

shown that artificial teeth cannot retain satisfactorily the natural contour of the cheeks, mouth, and chin as well

as can natural teeth. Lines and sagging of these features occur at an earlier age in the wearer of artificial teeth. , Finally it is only in cases where retention of natural teeth is obviously not good for. the healthwhere there are abscesses or pyorrhoea for example that any advantage to health can be shown. • Though . attention to diet—eating the right foods at the right times—may not prevent dental decay, it will certainly red nce its seventy. The reduction probably depends on general health, nn bararlitarv factors and I ) ° sslbiy 1 . n Hereditary tactors, ana others difficult to evaluate. Allied to regular and careful dental care howneed for S large lumbers ’ <rf V °young npnn i p + n rpcir ,?t to artificial teeth people 10 resorx 10 arunciai Teem Parents could do much to improve the dental health of New Zealanders by encouraging their children to clean their teeth regularly and correctly, and to eat foods such as raw fruits and vegetables, eggs, milk, and cheese, and by impressing on them a respect for natural teeth.