The Influence of Teeth, Diet, and Habits on the Human Face

178 Pages·1972·4.288 MB·English

by  D. M. Davies (Auth.)

THE INFLUENCE OF TEETH,
DIET, AND HABITS ON THE
HUMAN FACE
D. M. DAVIES
WILLIAM HEINEMANN MEDICAL BOOKS LTD
LONDON
First Published 1972
© D. Μ. Davies 1972
ISBN 433 07160 5
Made in Great Britain at the Pitman Press, Bath
PREFACE
DURING the past few decades there have been many radical changes
in the diet of 'civilized' man, and not all of them to his advantage.
Dental health has deteriorated rapidly and facial degeneration has
also become much more common. It seemed that it would be of
interest, and perhaps of value, to see how primitive tribes fared on a
'natural' diet.
But this is not the only objective of the book. There has been no
previous study of the relationship of diets and habits and their influence
upon the human face, a subject which should be of interest to many
serious students of human biology, anthropology, psychology, anatomy,
zoology, evolution and nutrition. For facial features are not entirely
hereditary, environment, and particularly social environment, plays its
important part.
To take things a stage further is to see how the features and dental
health of primitive tribes are influenced, indeed it would not be too
strong to say formed, by their specialized, primitive diets. And it is this
that forms the central theme of this work, the teeth and jaws of savage
man, the diseases and abnormalities that are found in them. In many
cases following peoples to the sad, logical conclusions of degenerate,
malformed features and diseased teeth, that follows upon the introduc-
tion and adoption of a 'civilized', unsuitable diet.
In the course of research for this work, the skulls of twenty different
tribes from widely scattered parts of the world were studied. Owing to
the difficulty of obtaining living specimens the material used came
principally from the British Museum's collection of fourteen thousand
specimens; four hundred and fifty were selected for use in the study
that will be described in the following pages. The main criteria for the
selection of these specimens was as follows:
(1) They were selected from regions of the world where, up to the
time of collection, there had been no contact with civilization;
(2) The data indicated that they were collected during the nine-
teenth century—at least no later.
Therefore, in the work on these specimens, we are studying original
man; before his way of life had been altered by contact with civilization.
Observations have also been made in respect to the customs and
habits (e.g. tooth filing and betel nut chewing), of the tribes concerned
to show their effects, as well as the effects of natural disease.
iii
iv PREFACE
Teeth form a particularly valuable subject for study to those interested
in man as they are the most indestructible part of the body, and they
can help to provide records of age, health, racial links, customs, diet,
and eating habits for many years after the person who animated them
is dead.
Finally, all scientific men agree that in the teeth we have one of the
best forms of evidence of evolutionary relationship.
D.M.D.
London, January 1972
ACKNOWLEDGEMENTS
THIS study and research was undertaken partly during the tenure of a
Medical Research Council Grant, and therefore I am greatly indebted
to them for their financial support.
The work was carried out in two centres, The British Museum of
Natural History and University College Hospital Dental School.
I am grateful to the authorities at The British Museum of Natural
History for access to specimens, and for providing the necessary facili-
ties for examining them. The initial selection, measurements, and
observations were carried out there. The officers there who were par-
ticularly helpful were Dr. K. P. Oakley, the Deputy Keeper and Head
of the Sub-Department of Anthropology; Mr. Don Broth well, and
Miss Rosemary Powers.
Amongst colleagues at University College Hospital Dental School, I
should like to give grateful thanks to Professor A. S. Prophet, the
Director of Dental Studies, and to Dr. D. C. A. Picton, the Professor in
Experimental and Preventive Dentistry, for their guidance, encourage-
ment and inspiration.
Also my thanks to Mr. A. G. Alexander, for his observations on the
specimens, which gave me several leads, and for comparing the measure-
ments with the Russell Index.
On the technical side, my thanks to Mr. Rogers and his successor,
Mr. Day, of the Photographic Department, for their superb photo-
graphs of the material, and their patience and eagerness to help in the
project, and to Miss Mildred Hughes, the Senior Radiographer in the
Dental Hospital, for her assistance and advice with the radiographical
side of the work, and Madeline Bentley for the illustrations.
Miss S. Devine of the Medical Research Council Computer Service
gave great help with the statistics and the computer programming.
Finally, I wish to express my appreciation and thanks to the many
University College Hospital Dental School staff and friends, who have
encouraged me in the work, and also given of their time and co-operation
in order that this work could be completed. Also to friends at University
College who gave of their time when I required information on special
subjects not covered in the University College Hospital Dental School.
I should also like to express my thanks to Miss Elizabeth Clay for
enabling me to complete the work by helping me with the final editing,
typing, etc., and to the other secretarial assistants who undertook the
laborious task of typing the Tables.
September 1971 D.M.D.
INTRODUCTION
THE tooth is made up of four structures. The first is the pulp, within
which carries blood vessels and nerves. This structure is surrounded in
both the root and crown by the dentine or tooth bone which is nourished
from within. The dentine of the root is covered by cementum which
receives nourishment from the membrane which attaches the root to
the jaw bone. The dentine of the crown or exposed part of the tooth is
covered with enamel. Tooth decay proceeds slowly through the enamel
and often rapidly in the dentine, always following the minute channels
towards the pulp, which may become infected before the decay actually
reaches the pulp to expose it; nearly always the decay infects the pulp
when it destroys the dentine covering it. When a tooth has a deep
cavity of decay, the decalcified dentine has about the density of rotten
wood. With an adequate improvement in nutrition, tooth decay will
generally be checked provided two conditions are present: in the first
place, there must be enough improvement in the quality of the saliva;
and in the second, the saliva must have free access to the cavity. Of
course, if the decay is removed and a filling placed in the cavity, the
bacteria will be mechanically shut out. One of the most severe tests of
a nutritional programme, accordingly, is the test of its power to check
tooth decay completely, even without fillings. There are, however,
two further tests of the sufficiency of improvement of the chemical
content of the saliva. If it has been sufficiently improved, bacterial
growth will not only be inhibited, but the leathery decayed dentine will
become mineralized from the saliva by a process similar to petrification.
The work that is described in the following pages was carried out in
the Dental Department of the University College Hospital Medical
School and in the Sub-Department of Anthropology at the British
Museum of Natural History, Cromwell Road, South Kensington.
Occasional visits were made as well to the Duckworth Laboratory at
the Downing Street Site at Cambridge and the Zoology Department at
Oxford, and the Royal College of Surgeons when it became necessary
to study skulls of the types not available at the British Museum.
Before the study began it was feared that there would be too little
material available with sufficient teeth present to yield much informa-
tion. However, out of the fourteen thousand or so specimens that are
housed in the British Museum, there were plenty with teeth in situ. In
fact perfect dentitions were quite common amongst the primitive tribes
studied. Loss of teeth during life was much more common among the
l
2 INTRODUCTION
more civilized groups of people and was especially common in the skulls
from the Scandinavian countries. These were mainly represented by
skulls from the Seamen's Hospital, that was originally at Greenwich,
and most of them dated from the period 1850-1900.
Early in 1963 the writer returned from doing fieldwork in Physical
Anthropology in New Guinea and South East Asia and started to do
some reconstruction, measurements of skulls, and anatomical work.
Many of the skulls and jaws studied had been damaged by bombing
during the war, especially those in the R.C.S. but others were new
additions that had arrived in a damaged state. Dental disease was found
to be quite common but there were differences in incidence and in the
type of abnormality between the different races. For instance, perio-
dontal disease was common amongst the Asian Indians, and the third
molars were often missing from the Chinese skulls. Impacted molars
also occurred in the Chinese, and in the aborigines of Australia.
While working in the Highlands of New Guinea, in the Central
Region, the writer noticed that periodontal disease appeared quite
frequently among the tribal people. When it occurred after the age of
thirty-five the writer had the impression that it had an influence on the
general health and the well-being of the individual, who appeared less
robust than others without the disease.
The study was carried out so as to include the general observations
as well as the anatomical ones. This included signs that might indicate
diseases such as periodontal disease. The incidence of caries was
also studied, and records were made of attrition, malocclusion,
hypoplasia, abscess cavities, odontomes, cysts, hypercementosis, and
exfoliation. Physical anomalies were also observed, such as tauro-
dontism shovel-shaped incisors, and supernumeraries. Records were
also made of the size of the molars, with reference to:
(i) diminution in size from the first to the third molar;
(ii) equal size of all molars;
(iii) the regular occurrence of one molar larger than all the rest.
A note was also made if any of the above features appeared peculiar to
any particular tribe. In some races the third molars were often absent,
for example, the Chinese, Eskimos, and American Indians (all peoples
of a Mongolian origin). In other races the third molars were commonly
impacted, for example, the Australian aborigines.
Variations in the palate and jaws were noted, including differences
in the size of the condyles and in the size and shape of the palate,
including cleft palate. This latter condition is rare among the speci-
mens that were studied, as few children in primitive societies were
allowed to grow up with this deformity, for fear that it was linked to
black magic.1 Types of prognathism, occlusion (class (i), (ii), and (iii)
1 Frazer, 1900.
INTRODUCTION 3
after Angle's classification), and attrition (after Pedersen's classification)
were also noted.
Some primitive tribes also mutilated thei r teeth by filing (e.g. in
Australian aborigines) and even by inserting brass studs in them
Nigeria), by knocking out the incisors, usually of the mandibles (e.g.
(e.g. in Borneo)—see Plate I, b and d, and Plate V, d.
Information about the diet and habits of primitive people was also
studied for their relation to the tooth conditions. Information was
obtained from the following sources:
(i) The British Museum Records;
(ii) The British Museum Anthropological Library;
(iii) The Library of the Royal Anthropological Institute in Bed-
ford Square;
(iv) The University College Hospital Medical School Library;
(v) The Food and Agricultural Organization;
(vi) The writer's own notes and reports, taken while studying
tribes in Siam, Lapland, New Guinea, Indonesia, and Canada;
(vii) The Museums of the Royal College of Surgeons.
The effects on the teeth and jaws of the following habits were recorded
when studying the skulls:
(i) the absence of tooth cleaning;
(ii) the use of cleaning sticks, leather, or grit for cleaning;
(iii) the use or the non-use of tobacco;
(iv) tooth filing;
(v) betel nut chewing;
(vi) the chewing on leather as practised by Eskimo women, in the
making of leather thonging and similar customs;
(vii) using the teeth in an occupation where it is necessary to bite on
materials other than those mentioned above, such as gut in
the making of bow strings and in the sewing of skins together;
these habits can be found in one tribe of Arctic Indians (the
Athabascans) and in one tribe in Central Australia (the
Arunta). It will be observed that these two peoples live far
apart yet have similar conditions.1 (Plate I, a and c.)
The teeth and the jaws may also be affected by changes in diet
brought about by:
(i) a change in the way of life through invasion by a foreign race;
(ii) adoption of new religious customs;
(iii) migration to areas yielding different foodstuffs;
(iv) alterations due to changes in agricultural methods;
(v) from a hard type diet to a sloppy food type.
1 Hillaby, 1963.
4 INTRODUCTION
A number of skulls of two types of primitive people, the New
Guineans and the Andamanese, were examined in a pilot study. It ap-
peared that in the New Guineans periodontal disease predominated
and caries in the Andamanese. The former had a more or less vegetarian
diet and the latter mainly a meaty one. Although, this did not provide
very much to go on, it did suggest that there might be some kind of
difference in the dental health between tribes that had a different diet,
and this small survey therefore provided a starting point.
Again, from the frequent forages into the wealth of this material,
one could not help but notice how, in some of the more primitive tribes,
certain groups had been more conspicuously attacked by periodontal
diseases than others.
Much of the material where the British Museum and the Royal Col-
lege of Surgeons were concerned, had been collected during the nine-
teenth century when there was a great exodus of collectors from Britain.
Often in fact the skulls were collected as an incidental part of some other
investigation, by such explorers in some cases as Stanley, Du'Chaillu,
and Baden Powell. At the time when the skulls were collected there had
been little contact between these primitive races and the civilizing
influences of the White Man. In the times between then and now some
of the tribes represented in the British Museum collections have become
extinct, for example, the Tasmanians and some Red Indian tribes, so that
a valuable and unique collection of material exists there. (Plate II, a.)
Skulls that were too old and had no relevance to the study (e.g.
those of Ancient Egypt and of the Incas), were not included, as they
often showed too much post-mortem disintegration of the bone of the
jaws, and also there was no accurate information about diet. Also
eliminated were skulls originating from lands where there had been
some contact with modern civilized diets, for example, parts of Europe
and South America, as well as those skulls of individuals who had
settled in countries other than their homeland, for example, overseas
Chinese and West Indian Negroes.
The skulls selected were from races and tribes which fell into two
main dietary groups, the meat eaters and the mainly vegetable eaters—
as shown in Table II. Each of these groups was divided into four sub-
sidiary groups. Duplicates to the examples that have been given in the
table could quite easily be found, since the particular diets were by no
means unique. For instance Eskimos, Lapps, and Samoyeds all have
very similar diets.
The objective in selecting meat-eating types and vegetarian types in
the first place was because they represented the two extremes in diet,
and if diet did have much influence on the dental health of primitive
people then it seemed probable it would show up in one way or another.
The reason why the New Guineans and the Andamanese were chosen
in the first place as representatives of vegetarian and meat-eating types
of men respectively was:
INTRODUCTION 5
(i) because they were well represented at the British Museum by
skulls with good dentitions;
(ii) they were readily available as the author was studying them
when the research began;
(iii) their diets were defined in The Living Races of Mankind1 as
belonging to the two groups of vegetarians and meat eaters.
In the early stages of the study it was thought that the consistency
of the diet would have most influence on the teeth and the surrounding
areas of the mouth. The possibility existed however that the systemic
effects of the diet following digestion would be of more importance.
One object of the study was to find out whether consistency or composi-
tion of the diet had the greater effect on periodontal health.
Dental Caries
It is currently established that there is a close link between dental
caries and a diet of high refined carbohydrate content, and also between
dental caries and neglect in cleaning the teeth.2
The high prevalence of caries in modern man has been blamed on
too much refined carbohydrate in both food and drink,3 and also on
lack of calcium in the diet.4
Man through the ages has suffered from dental caries, but there has
been a great increase in the incidence of the disease since prehistoric
times. Rhodesian Man, one of the earliest of fossil men to be found in
Africa, had some carious teeth; this can be seen easily in the cast of the
original in the Anthropological Gallery at the British Museum of
Natural History.
However, as sweetness is something of a luxury in primitive society,
usually coming in the form of honey, dental caries is correspondingly
rare.5 On the other hand there is an anomaly, for one of man's closest
relatives, the gorilla (Berengei berengei), lives almost entirely upon
sugar cane, but does not suffer from dental caries. Fourteen gorilla
skulls were examined and all were found to be caries free.
Primitive people living in their natural state have a very low per-
centage of carious teeth as the following figures show:
TABLE I (after Mellanby, 1922)
Race Percentage of Skulls Number of Skulls
with Caries studied
Maori 0-76 260
Eskimo (living) 2*90 69
Australian aborigines 2·30 1,490
1 Hutchinson, 1910.
2 Gustaffson et al, 1953, Fadich, 1956, and Horsnell, 1962.
3 Conclusions of Study Groups, World Workshop Conference on Nutrition, 1961.
4 Young, 1961.
6 Pedersen, 1937.