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THE PREVENTION OF DENTAL CARIES
245
subject not from the clinical standpoint but primarily as a biologist interested in structure and growth, has given a fresh orientation to the study the
of dental caries which has been of the utmost value. It is now generally admitted that the structure of the teeth both in animals and in man depends largely on an adequate supply of vitamin D, nor is her contention that the more perfect LONDON: S’ATr7RDAY, FEBRUARY 3, 19344 the structure the greater the resistance to dental caries now disputed. These premises being accepted, the natural conclusion is that an adequate supply of THE PREVENTION OF DENTAL CARIES a diet of high calcifying value during the formative THE appearance of the third reporton the period of the teeth would go far to abolish the inciand this is the main lesson of her dence of investigation into the structure of the teeth in work. A caries, issue of immense practical importance side relation to dental caries, carried out by Mrs. in this country where cereals are cheap and form a MAY MELLANBY over the last 17 years, completes large proportion of the diet of children is that a trilogy of which the author has every reason to cereals contain some substance inimical to calcibe proud. The three reports embody a mass of fication. Fresh evidence of this inconvenient fact work scarcely to be paralleled in dental science, has emerged as a result of the fourth investigation children, at Sheffield, in which the effects of a scientifically planned, skilfully controlled, cogently on The elaborate grading were tested. cereal-free argued, and carefully documented. In this final of human diet teeth by macroscopical and microvolume Mrs. MELLANBY marshals the evidence tests into various degrees of hypoplasia supplied by experiments on animals, by the scopical examination of a large number of teeth, and by has resulted in the acceptance of a standard of normality which is perhaps too strict ; it might a series of experiments on children with adequate controls. Starting off with the thesis, which has be argued that too little latitude is given to the been conclusively proved by work on animals, existence of variations within the range of the that calcification is controlled by vitamin D, she normal. The demonstration that the teeth in a went on to satisfy herself that human teeth, in community with a natural immunity to caries this country at any rate, show evidence of defective have a higher standard of structure than those structure (judged by the standard provided by found in the English race would provide further animal feeding experiments) which it seems logical confirmation of Mrs. MELLANBY’S thesis, and it to associate with vitamin deficiency. The next may be hoped that such an investigation will be stage was the demonstration by means of correla- made. But it is clear that a large proportion of tion of structure with the incidence of caries that both the deciduous and permanent teeth of the there is a definite association between perfect people in this country show a structure less perfect structure and freedom from dental caries. From than may normally be found in animals, and the this point she proceeded logically and naturally effort to achieve a better standard of structure to a series of feeding experiments on children by improving diet during pregnancy and childmaking. The controlled living under more or less fixed conditions and hood is certainly worthdescribed in this report experiments given a diet specially rich in vitamin D, while a feeding show that in the all to go presence of a parallel group without extra vitamins served as vitamin the of D liability to fresh controls. The results of these feeding experi- plentiful supply caries MELLANBY was lessened. Mrs. distinctly ments, it is claimed, provide conclusive proof of the theories suggested by animal experiments and suggests the following dietary principles : " The consumption of milk, eggs, cheese, animal and by a combined statistical, clinical, and micro- fish fats, and vegetables must be greatly increased, of teeth in situ or extracted. Finally, scopical study in the light of these various investigations, Mrs. and the consumption of cereals correspondingly MELLANBY states the general principles of feeding diminished, and, for the very young, abolished. which might be expected to result in a substantial Breast-feeding must be general and prolonged even reduction of dental disease among civilised races. up to a year or more, provided a supplementary It would of course be possible to pick holes in diet is given after about six months, which should this or that argument or to point out that some include some iron and vitamin C. Cod-liver oil, of the findings might well be explained in other or some other source of fat-soluble vitamins should to all infants and children." ways and do not necessarily exclude other hypo- be given While we acknowledge the value of this contritheses. But there is little doubt that for many bution to preventive medicine, we would deprecate years the attention of the dental profession has been focused too closely on the environment of any tendency to decry attempts to promote and the teeth and too little on the teeth themselves. maintain oral hygiene, at any rate until it is The fact that Mrs. MELLANBY has approached definitely proved that the dietetic environment is a negligible factor in dental caries. Is it quite 1 Diet and the Teeth : An Experimental Study. Part III. whether the diet be sticky or detergent, immaterial The Effect of Diet on Dental Structure and Disease in Man. rich or By May Mellanby. Medical Research Council, Special Report poor in fermentable carbohydrates, proSeries No. 191. H.M. Stationery Office. 1934. Pp. 180. 5s. vided that the teeth are well calcified, and that Parts I. and II. of this study appeared as Nos. 140 (1929) and 153 (1930) of the Special Report Series. the diet provides for the laying down of secondary -
THE LANCET
246
It would be premature to assume that, vitamin D is taken, the physical sufficient provided characters of the food do not matter ; that sweets can be sucked with impunity and biscuits eaten before bedtime ; that food which requires vigorous mastication has no merit over that which is soft and sticky; and that the toilet of the mouth has aesthetic rather than hygienic value. Surely there is room for both methods of trying to combat dental disease.
dentine ?
PSYCHOLOGY OF QUACKERY
correspond around
to the different attitudes
neither
we
may
see
assert that
to-day; psycho-analytical interpretation of the phenomena of quackery, such as Dr. RICKMAN suggested, is adequate to explain the perennial mountebank and his train of gulls and admirers. But informed speculation about this obscure matter is desirable until more immediate data have been collected by close examination of the minds of quacks and us
can we
clients. There is another aspect to the problem, lately stressed by Prof. H. BURGER, of Amsterdam, in his address at the Royal Society of Medicine.1 The successes of the quack are sometimes undeniable, but they are relatively few, and they are not relevant to the issue between him and the trained worker ; the test of rational therapy lies more in the certainty than the number of its triumphs. The quack works by intuition rather than rule, and his expectation is sanguine ; consequently he is efficacious sometimes, harmful often, confident always, justly certain never. Which patients will have the psychogenic disorders or mental attitudes which make them sure to respond to such artifices as his he cannot foretell. A careful study of the people who are benefited by the quack would throw light not only on their attitude towards disease and healing but also on the criteria of efficacy for certain forms of psychotherapy. No matter what the particular nostrums employed, the methods of the quack make use of tendencies in the sick which are familiar to the psychiatrist, though doctors do not always avail themselves of them as they might. They should not be ignored. A little honest propaganda about such matters might be well advised. When the public grasps what kind of disorders can be benefited by psychotherapy-whether orthodox or casual and blind-and sees that these ends can better be achieved by rational than by haphazard methods, there will be less of facile wonder at the quack’s occasional successes, though it would perhaps he utopian to expect his practice to dwindle correspondingly. Those other forces which were discussed at the British Psychological Society are too old and obstinate to be ousted lightly. Before they can be ousted, they must be studied and understood.
So familiar and near an evil as quackery naturally receives attention in medical journals, but, although there are many historical and social studies, the psychological factors in its maintenance are seldom examined. This is a pity if quackery is to be attacked successfully. Demonstrations of how worthless and unscientific such treatment may be are of no force when offered to people who do not judge on scientific grounds-and the public which comes to be cozened is not made up of rational critics. Moral fervour against the quack serves far less purpose than inquiry into the minds of his supporters. There are many kinds of quacks, each with an attendant trusting band ; it is not reasonable to suppose that all the quacks are conscious charlatans and that all their customers are dupes. Some quacks are doubtless honest ; some patients of quacks may be benefited. But the age-old prosperity of the quack rests on firmer ground than his occasional sincerity or therapeutic The modes of thought which lead people success. of every class of society and of every kind of education to seek the charlatan’s guidance are of permanent importance, while his knowledge and arts change with each decade. What the charlatan preaches or does is often the stale medicine of an earlier century, laced with magic ; what he appeals to is the same now as in the days of Tabarin or Trotula. In the address from the chair to the medical section of the British Psychological Society Dr. JOHN RICKMAN has done a service in inquiring into this matter. He was able to point to analogies in the behaviour of races with a very different culture from ours. The shaman, for example, who holds so important a position in the north and east of Asia, has considerable medical functions, DIPHTHERIA IMMUNITY AMONG ISOLATED and it is possible that the attitude of those who use him to relieve them of their demons is closely RACES related in its essentials to that of many who in THE problem of racial immunity to infective our civilisation furnish the wherewithal for quacks diseases has always been one of great interest to to grow fat. The development of priesthood, sometimes even coexisting with shamanism in the medical biologists and although much material has now accumulated it can yet hardly be said same society, furnishes further material of comwe are in a position to have any clear views parison ; method and training, and, later, rational that on the subject, particularly in the case of those thinking have been the criteria by which it became diseases in which environmental conditions or possible to distinguish the quack from the scientific the habits of the people fail to provide an explanahealer, as the shaman could be distinguished from tion of the distribution of the disease. There is the priest or from the observer who relied on what no infectious disease about which we had been discovered rather than on intuition or probably know so much, and so many sides, as from magic. It would be going too far to say that the The means of isolating and identifying stages represented by shaman, priest, and scienti- diphtheria. are almost perfect and the methods the bacillus fically trained observer are those through which 1 THE LANCET, 1933, ii., 1148. European medicine has passed, or that they
subject not from the clinical standpoint but primarily as a biologist interested in structure and growth, has given a fresh orientation to the study the
of dental caries which has been of the utmost value. It is now generally admitted that the structure of the teeth both in animals and in man depends largely on an adequate supply of vitamin D, nor is her contention that the more perfect LONDON: S’ATr7RDAY, FEBRUARY 3, 19344 the structure the greater the resistance to dental caries now disputed. These premises being accepted, the natural conclusion is that an adequate supply of THE PREVENTION OF DENTAL CARIES a diet of high calcifying value during the formative THE appearance of the third reporton the period of the teeth would go far to abolish the inciand this is the main lesson of her dence of investigation into the structure of the teeth in work. A caries, issue of immense practical importance side relation to dental caries, carried out by Mrs. in this country where cereals are cheap and form a MAY MELLANBY over the last 17 years, completes large proportion of the diet of children is that a trilogy of which the author has every reason to cereals contain some substance inimical to calcibe proud. The three reports embody a mass of fication. Fresh evidence of this inconvenient fact work scarcely to be paralleled in dental science, has emerged as a result of the fourth investigation children, at Sheffield, in which the effects of a scientifically planned, skilfully controlled, cogently on The elaborate grading were tested. cereal-free argued, and carefully documented. In this final of human diet teeth by macroscopical and microvolume Mrs. MELLANBY marshals the evidence tests into various degrees of hypoplasia supplied by experiments on animals, by the scopical examination of a large number of teeth, and by has resulted in the acceptance of a standard of normality which is perhaps too strict ; it might a series of experiments on children with adequate controls. Starting off with the thesis, which has be argued that too little latitude is given to the been conclusively proved by work on animals, existence of variations within the range of the that calcification is controlled by vitamin D, she normal. The demonstration that the teeth in a went on to satisfy herself that human teeth, in community with a natural immunity to caries this country at any rate, show evidence of defective have a higher standard of structure than those structure (judged by the standard provided by found in the English race would provide further animal feeding experiments) which it seems logical confirmation of Mrs. MELLANBY’S thesis, and it to associate with vitamin deficiency. The next may be hoped that such an investigation will be stage was the demonstration by means of correla- made. But it is clear that a large proportion of tion of structure with the incidence of caries that both the deciduous and permanent teeth of the there is a definite association between perfect people in this country show a structure less perfect structure and freedom from dental caries. From than may normally be found in animals, and the this point she proceeded logically and naturally effort to achieve a better standard of structure to a series of feeding experiments on children by improving diet during pregnancy and childmaking. The controlled living under more or less fixed conditions and hood is certainly worthdescribed in this report experiments given a diet specially rich in vitamin D, while a feeding show that in the all to go presence of a parallel group without extra vitamins served as vitamin the of D liability to fresh controls. The results of these feeding experi- plentiful supply caries MELLANBY was lessened. Mrs. distinctly ments, it is claimed, provide conclusive proof of the theories suggested by animal experiments and suggests the following dietary principles : " The consumption of milk, eggs, cheese, animal and by a combined statistical, clinical, and micro- fish fats, and vegetables must be greatly increased, of teeth in situ or extracted. Finally, scopical study in the light of these various investigations, Mrs. and the consumption of cereals correspondingly MELLANBY states the general principles of feeding diminished, and, for the very young, abolished. which might be expected to result in a substantial Breast-feeding must be general and prolonged even reduction of dental disease among civilised races. up to a year or more, provided a supplementary It would of course be possible to pick holes in diet is given after about six months, which should this or that argument or to point out that some include some iron and vitamin C. Cod-liver oil, of the findings might well be explained in other or some other source of fat-soluble vitamins should to all infants and children." ways and do not necessarily exclude other hypo- be given While we acknowledge the value of this contritheses. But there is little doubt that for many bution to preventive medicine, we would deprecate years the attention of the dental profession has been focused too closely on the environment of any tendency to decry attempts to promote and the teeth and too little on the teeth themselves. maintain oral hygiene, at any rate until it is The fact that Mrs. MELLANBY has approached definitely proved that the dietetic environment is a negligible factor in dental caries. Is it quite 1 Diet and the Teeth : An Experimental Study. Part III. whether the diet be sticky or detergent, immaterial The Effect of Diet on Dental Structure and Disease in Man. rich or By May Mellanby. Medical Research Council, Special Report poor in fermentable carbohydrates, proSeries No. 191. H.M. Stationery Office. 1934. Pp. 180. 5s. vided that the teeth are well calcified, and that Parts I. and II. of this study appeared as Nos. 140 (1929) and 153 (1930) of the Special Report Series. the diet provides for the laying down of secondary -
THE LANCET
246
It would be premature to assume that, vitamin D is taken, the physical sufficient provided characters of the food do not matter ; that sweets can be sucked with impunity and biscuits eaten before bedtime ; that food which requires vigorous mastication has no merit over that which is soft and sticky; and that the toilet of the mouth has aesthetic rather than hygienic value. Surely there is room for both methods of trying to combat dental disease.
dentine ?
PSYCHOLOGY OF QUACKERY
correspond around
to the different attitudes
neither
we
may
see
assert that
to-day; psycho-analytical interpretation of the phenomena of quackery, such as Dr. RICKMAN suggested, is adequate to explain the perennial mountebank and his train of gulls and admirers. But informed speculation about this obscure matter is desirable until more immediate data have been collected by close examination of the minds of quacks and us
can we
clients. There is another aspect to the problem, lately stressed by Prof. H. BURGER, of Amsterdam, in his address at the Royal Society of Medicine.1 The successes of the quack are sometimes undeniable, but they are relatively few, and they are not relevant to the issue between him and the trained worker ; the test of rational therapy lies more in the certainty than the number of its triumphs. The quack works by intuition rather than rule, and his expectation is sanguine ; consequently he is efficacious sometimes, harmful often, confident always, justly certain never. Which patients will have the psychogenic disorders or mental attitudes which make them sure to respond to such artifices as his he cannot foretell. A careful study of the people who are benefited by the quack would throw light not only on their attitude towards disease and healing but also on the criteria of efficacy for certain forms of psychotherapy. No matter what the particular nostrums employed, the methods of the quack make use of tendencies in the sick which are familiar to the psychiatrist, though doctors do not always avail themselves of them as they might. They should not be ignored. A little honest propaganda about such matters might be well advised. When the public grasps what kind of disorders can be benefited by psychotherapy-whether orthodox or casual and blind-and sees that these ends can better be achieved by rational than by haphazard methods, there will be less of facile wonder at the quack’s occasional successes, though it would perhaps he utopian to expect his practice to dwindle correspondingly. Those other forces which were discussed at the British Psychological Society are too old and obstinate to be ousted lightly. Before they can be ousted, they must be studied and understood.
So familiar and near an evil as quackery naturally receives attention in medical journals, but, although there are many historical and social studies, the psychological factors in its maintenance are seldom examined. This is a pity if quackery is to be attacked successfully. Demonstrations of how worthless and unscientific such treatment may be are of no force when offered to people who do not judge on scientific grounds-and the public which comes to be cozened is not made up of rational critics. Moral fervour against the quack serves far less purpose than inquiry into the minds of his supporters. There are many kinds of quacks, each with an attendant trusting band ; it is not reasonable to suppose that all the quacks are conscious charlatans and that all their customers are dupes. Some quacks are doubtless honest ; some patients of quacks may be benefited. But the age-old prosperity of the quack rests on firmer ground than his occasional sincerity or therapeutic The modes of thought which lead people success. of every class of society and of every kind of education to seek the charlatan’s guidance are of permanent importance, while his knowledge and arts change with each decade. What the charlatan preaches or does is often the stale medicine of an earlier century, laced with magic ; what he appeals to is the same now as in the days of Tabarin or Trotula. In the address from the chair to the medical section of the British Psychological Society Dr. JOHN RICKMAN has done a service in inquiring into this matter. He was able to point to analogies in the behaviour of races with a very different culture from ours. The shaman, for example, who holds so important a position in the north and east of Asia, has considerable medical functions, DIPHTHERIA IMMUNITY AMONG ISOLATED and it is possible that the attitude of those who use him to relieve them of their demons is closely RACES related in its essentials to that of many who in THE problem of racial immunity to infective our civilisation furnish the wherewithal for quacks diseases has always been one of great interest to to grow fat. The development of priesthood, sometimes even coexisting with shamanism in the medical biologists and although much material has now accumulated it can yet hardly be said same society, furnishes further material of comwe are in a position to have any clear views parison ; method and training, and, later, rational that on the subject, particularly in the case of those thinking have been the criteria by which it became diseases in which environmental conditions or possible to distinguish the quack from the scientific the habits of the people fail to provide an explanahealer, as the shaman could be distinguished from tion of the distribution of the disease. There is the priest or from the observer who relied on what no infectious disease about which we had been discovered rather than on intuition or probably know so much, and so many sides, as from magic. It would be going too far to say that the The means of isolating and identifying stages represented by shaman, priest, and scienti- diphtheria. are almost perfect and the methods the bacillus fically trained observer are those through which 1 THE LANCET, 1933, ii., 1148. European medicine has passed, or that they