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Caries and crowding in the teeth of the living Alaskan Eskimo.

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CARIES AND CROWDING I N T H E TEETH O F T H E
LIVING ALASKAN ESKIMO
HENRY B. COLLIXS, JR.
Division of Ethnology, 17. S . National Museum
As a result of the increasing amount of research being devoted to the problem of the etiology of dental caries, the foremost authorities now generally recognize that a number of
factors have to be taken into account before a wholly satisfactory explanation is reached. Bunting, whose researches
have dolie much toward elucidating the r81e of bacteria in the
production of dental decay, says :
To one who has studied the literature carefully it becomes apparent
that the disease in question is not a simple pathologic process which
can be categorically stated. Rather, it is a complicated syndrome in
which the lesion of the tooth is but the ultimate expression of a wide
variety of local and systemic factors . . . . the Michigan group are
convinced that dental caries is in reality an infective disease and that
the speoific organism involved is B. acidophilus. . . . J t must be
recognized, however, that the growth of B. acidophilus and the activity
of dental caries are not wholly dependent on or determined by
primarily local conditions in the mouth. Clearly, the growth and
activity of the specific bacteria of dental caries are governed by many
underlying constitutional factors such as heredity, age, nutrition and
general bodily health. These general metabolic states secondarily
produce environmental conditions in the mouth which a r e favorable
o r unfavorable to the growth and characteristic activity of the cariesforming organisms.1
The fact that different races of man show varying degrees
of resistance to caries raises the question a s to whether race
is one of the factors involved, or, more likely, whether race
is a mask which obscures the real factors. Light may be
Bunting, Russell W. Certain considerations in the problem of dental caries.
Dental Cosmos, L X S I I , no. 4, April, 1930, 399-407.
451
AMERICAN J O U R N A L O F P H Y S I C A L ANTHROPOI.OGY, VOL. XVI, NO.
A P R I L r J U N E , 1933
4
452
H E S R Y B. COLLISS, JR.
thrown on the problem by observing the changes brought
about i n the condition of the teeth of priniitive peoples as they
come into contact with civilization. As far as the literature
oil the subject reveals, such changes without exception have
been i n the direction of increased susceptibility to caries, and
apparently the most important factor in each case has been
that of a n altered diet.
An interesting example is afforded by the Eskimo, who
before coming into contact with white civilization possessed
teeth which were to a remarkable degree free from caries.
Leigh found caries i n only four, or 1 per cent, of 395 Eskimo
crania examined.* Goldstein, i n the present number of this
journal, records the finding of fifty-three Eskimo mandibles
affected by caries out of a total of 807, or a percentage of 6.6.
These low percentages of caries a r e the more remarkable
because of the advanced stages of attrition usually present.
The present paper supplements these findings on skeletal
material of a n earlier period by data on the living Eskimo,
obtained by the writer during the summers of 1927 to 1930
while engaged i n archeological and anthropometrical work
in Alaska. No claim is made that the examination of the
teeth was, from a dental standpoint, exhaustive or complete.
The instances of caries recorded were only those that were
visible-as a rule, on the occlusal surfaces; a dental explorer
was not used. Undoubtedly a rigorous examination made in
accordance with modern dental technique would reveal a
higher percentage of caries for all groups.
Observations were also taken on crowding of the teeth.
Crowding has here been used to denote those cases in which
the normal aligiment of the teeth had been interfered with,
whether by means of rotated incisors or by the actual displacement of a canine or other tooth through lack of space.
The Eskimo settlements visited were certain of those along
the Alaskan coast from Bristol Bay northward through
Bering Strait and up the Arctic coast to Point Hope. Within
*Leigh, R. 1%'.
1925. 581-898.
Dental pathology of the Eskimo.
Dental Cosmos, L X V I I , 9,
C A N E S AKD CROWDING I N TEETH O F ESKIMO
453
this a r e a live the most primitive group of Eskimo remaining
in Alaska-those on Nunivak Island and the adjoining mainland-and
also, further north around Seward Peninsula,
Eskimos who f o r a generation or more have been in fairly
close contact with whites, and whose mode of living has been
considerably affected thereby.
GEOGRAPHICAL DISTRIBUTION O F C A R I E S
The first observations were made a t Kanakanak, on Bristol
Bay, where the U. S. Bureau of Education maintains a n
orphanage, hospital, and industrial training school f o r the
Eskimo children from nearby settlements. Forty-two fullblood and seven mised-blood Eskimo children of both sexes,
together with two adults, were examined. Of the forty-two
full-blood children, eleven had one or more carious teeth or
teeth which had been extracted because of caries. Of the
seven mixed bloods, one had had two teeth extracted because
of caries. The Eskimos of the Bristol Bay region have been
subjected to white influence for more than a generation and
though their food habits have not changed to the extent of
the Kskimos around Nome or Kotzebue Sound, a certain
amount of white food has entered into their diet. The diet
of the orphanage children a t Kanakanak is about what would
be found in similar institutions in the States except for thf
addition of reindeer meat and salmon.
Bristol Bay is the last center of white population along the
coast until St. Michael, on Norton Sound, is reached. Along
the entire 5OO-mile stretch of coast between Bristol Bay and
Korton Sound there dwell less than a dozen white families,
and most of these a r e of the teachers at the government
schools. The region is lacking in any resources which might
bring about commercial activity and is seldom visited by ships
because the shallow water and prevalence of high winds make
navigation dangerous. As a result of such isolation the
Eskimos of this section of southwest Alaska a r e the least
civilized of a n y i n the Territory. Their diet-mainly
fish,
seal, walrus, birds, white whale-has remained unchanged and
454
HENRY B. COLLIRS, JR.
i n other respects as well their primitive mode of life has
continued.
Of all the Eskimos in this region, those on Nunivak Island
have been least affected by contact with white civilization,
and it is interesting to note that in the sixty-six individuals
examined only two instances of caries were observed (table 1).
A t Hooper Bay, a n isolated Eskimo village on the mainland
northeast of Nunivak Island, the teeth of the twenty-two
adults a n d three children examined were free from caries.
Table 1 shows how caries increases as we leave southwest
Alaska, with its primitive population and proceed northTABLE 1
- ___. ~ _ _
Incidence of caries in relation lo locality
__.__
LOCALITY
ii
Kanakanak, Bristol Bay
Nunivak Island
Hooper Bay
Nome
i
King Island
St. Lawrence Island
Shishmareff
Kotzebue and Kivalena
Point Hope
1
,'
l
'
1
I
--
__-.
I
I
I
~_
51
66
25
9
21
61
1 8
28
17
CARIES
CUOWDEI) TEETH
1
Number I Per cent
__._ -,-.
- --
--
I Xumber
Per cent
_
- .~.
- -.
-
'
I
1
12
2
..
7
1
I
1
1
8
30
3
14
3
~
1
23.5
3.0
....
77.8
38.1
49.2
16.7
50.0
17.6
I
4
4
2
4
4
9
4
14
1
'
7.s
6.0
8.0
44.4
19.0
11.8
22.2
50.0
5.9
ward along the coast where the Eskimos a r e in closer contact
with civilization. I n contrast to the two individuals with
carious teeth among the ninety-one examined from Nunivak
Island and Hooper Bay, we find caries in seven of the nine
Eskimos examined at Some. Nome is the largest white settlement i n northern Alaska and the Eskimos living there have
for the most p a r t completely given u p their old mode of life.
King Island is a small rocky island lying off the coast of
Seward Peninsula between Bering Strait and Nome. F o r the
past ten o r twelve years these Eskimos have made a practice
of leaving their island home and coming to Some, where they
camp during the summer months, working as longshoremen
CARIES A N D CROWDING I N TEETH O F ESKIMO
455
and carving ivory for sale. During their stay at Nome they
subsist largely on white man’s food and take back considerable quantities with them when they return t o King Island
in tlie fall. Of the eight King Island Eskimos below twenty
years of age examined, seven had teeth which were affected
by caries. The one exception was a boy, ten years old, who
had lived all his life a t King Island and St. Lawrence Island.
Every King Island child examined, therefore, who had lived
a t Some had carious teeth. But this was not true of the
adults, for of the thirteen examined only one showed active
caries (a single lower second molar). Six others had missing
teeth, but since all but one of these individuals were above
forty years of age, most of these teeth had in all likelihood
been lost following exposure of the pulp cavities through
attrition.
The St. Lawrence Island Eskimos also show a relatively
high incidence of caries, 49.2. These a r e the most prosperous
of the Alaskan Eskimos, due to the large number of white
foxes they a r e able to t r a p and the ‘fossil’ walrus ivory they
dig up at the old village sites and sell. The St. Lawrence
Islanders a r e too far from the mainland of Alaska to make
the journey by boat as do the King Islanders, but nevertheless civilization of a sort is brought to them by the traders
who annually visit the two settlements of Gambell and
Sevunga. I n addition to the supplies left by the traders they
a r e able to secure flour, sugar, tea, coffee, caiined goods, etc.,
in almost any amount through the two stores at Gambell and
Sevunga which a r e operated by the natives themselves under
the guidance of the Bureau teachers. Caries was found as
follows: in twenty-one out of forty-three individuals below
twenty-one years of age; in eight out of eleven between the
ages of twenty-one and thirty; in one individual out of seven
above the age of thirty-one. Here again the preponderance
of caries occurs among the adolescents and younger adults.
The principal center of white population on the Arctic
coast is at Kotzebue. Fifty per cent of the Eskimos from
Kotzebue and the neighboring village of Kivalena that were
456
H E N R Y B. COLLINS, J R .
examined had carious teeth-a percentage exceeded only by
that of the small group from Nome.
To the west and north, respectively, of Kotzebue are the
two Eskimo settlements of Shishmareff and Point Hope; a t
these places there was found a caries incidence of 16.7 and
17.6, respectively. At both places there is a store from which
food supplies may be obtained, and while trading ships also
call, these two settlements are in every sense more isolated
than Kotzebue.
The conclusion to be drawn from table 1 seems to be that
dental caries among the Alaskan Eskimo is directly correlated
with their proximity to white settlements, the highest percentages being found among those groups (Nome, Kotzebue,
St. Lawrence, and King Island) having the closest contact
with whites and lowest among those (h’univak Island and
Hooper Bay) having the least of such contact.
The number of carious teeth per affected individual had
a similar distribution. At King Island the average number
of carious teeth per affected individual was 5.5 ; at Kotzebue,
3.7; Nome, 3.4; Shishmareff, 3.0; St. Lawrence Island, 2.9;
Kanakanak, 1.5 ; Point Hope and Nunivak Island, 1.0.
From a recently published survey of health conditions in
Greenland we see that, as in Alaska, dental caries occurs
more frequently among the Eskimos having contact with
white civilization than among those living a t the more
isolated settlements :
As a fact presumably bearing upon their diet, it is to be noted that
tooth caries, which in Denmark is to be found in about 97 per cent of
the population, in Greenland occurs in rather more than half of the
population at the settlements, but only in a fourth a t the outposts,
where the manner of living is upon the whole less influenced by
European c i v i l i ~ a t i o n . ~
The statement is sometimes made that dental caries increases when a race of low susceptibility becomes mixed with
a race of higher susceptibility. Therefore, in comparing the
Bertelsen, Alfr.
p. 381.
Greenland, vol. 3, 1929, Sanitary conditions i n Greenland,
C A R I E S A K D C R O W D I N G Ih’ TEETH O F E S I i I M O
457
26.7 per cent, of living Eskimos having carious teeth with the
6.6 per cent reported by Goldstein 011 Eskimo skeletal material
of a n earlier period, it is necessary to inquire whether or not
t,he higher incidence found in the living might be due to white
mixture. In the present, series of 296 Eskimos, twenty-seven
may with certainty be regarded as mixed bloods. Of these
twenty-seven, nine, or 33 per cent, had one or more carious
teeth. While this percentage is slightly higher than the 26
per cent shown f o r the remaining 269 full bloods, the difference is not great enough to indicate that race mixture has
af’fected the result to a n y appreciable extent. Furthermore,
seven of the nine mixed bloods who had carious teeth came
from Kotzebue, K i a g Tslancl, or Kome, a t which places the
Kskimos were all living in close contact with white civilization
and ate considerable quantities of white man’s food. It would
appear legitimate, therefore, to rule out race mixture as a
determining factor in the present case aid t o attribute the
increased susceptibility to caries to a changed mode of living
and p a r t i c d a r l y to an altered diet.
CROWDED TEETH
Crowded teeth, while as a rule less fyequent than caries,
showed a similar geographical distribution, the highest percentages being found at Kotzebue, Xome, Shishmareff, and
King Island, with lower percentages for St. Lawrence Island,
Rooper Bay, Nunivak Island, Kanakanak, and Point Hope.
Seven of the twenty-seven mixed bloods had crowded teeth,
a percentage of 25.9. This is higher than the 14.5 found in
the remaining 269 full bloods, but again as in the case of
caries, five of the seven mixed bloods with crowded teeth
were from Kotzebue, Nome, and King Island, where, as we
have seen, the Eskimos a r e in closer contact with civilization
than elsewhere.
F o r the purpose of obtaining comparative data on the incidence of tooth crowding among the Eskimo of a n earlier
period, 324 crania i n the h’ational Museum were examined.
Thirty-eight were subadults and of these, one, or 2.6 per cent,
458
H E N R Y B. COLLINS, JR.
had crowded teeth. Of the 286 adults, eight, or 2.8 per cent,
had crowded teeth. This low percentage compared with the
15.5 per cent found i n the living Eskimo would seem to
indicate that crowding of the teeth, like caries, is for the most
p a r t a recently acquired condition, the result, very likely,
of changed food habits.
AGE DIFFERENCES
The distribution of caries and crowded teeth in relation to
age is shown in table 2. The individuals most frequently
affected by caries were the adolescents in the thirteen- to
twenty-year groups, the young adults from twenty-one to
TABLE 2
Inczdence of canes an relation t o agp groups
--
_~_-__-__-__
AGE,
.
I
YEABS
6to 8
9 to 12
13 to 16
1 7 to 20
21 to 30
31 to 40
4 1 and above
1
'
_ _ _ _ _- -
Total
-
__
I
NUMBER
I
I
1
296
1
I
~-
~
/umber
29
41
60
42
-- --
__
-
CBOWDED TBETH
CAEIES
4
14
19
18
13
__
79
I
1
j
13.8
31.4
31.7
43.0
36.1
15.2
!-2-
I
I
8
1
I
12
11
7
1
1
/-26.7--(-46
Per cent
- 6.9-
,
,
-I--
-
19.5
20.0
26.2
19.4
2.2
-
15.5
--
thirty years, and the children from nine to twelve, with the
younger children, mainly with deciduous dentitions, and the
adults above forty-one years showing a markedly lower
incidence.
Crowded teeth were distributed in almost exactly the same
way. However, a point of interest appears in the fact that
only 2.2 per cent of the individuals above the age of forty-one
had crowded teeth-a greater difference than was shown for
the same group in regard to caries. On the basis of these
figures, the older living Eskimos compare favorably with
the prehistoric population, which would indicate that the conditions which have produced crowded teeth in 19.2 per cent
of the younger individuals of the present day were not
CARIES A N D CROWDING IN TEETH OF E S K I M O
459
operative a generation ago when the teeth of the older living
individuals were in a formative stage.
SEX DIFFERENCES
With regard to sex, it was found that the males, both young
and adults, showed a somewhat higher incidence of caries
than did the females (table 3 ) . This is not the condition
usually found in other races, but it conforms to the results
obtained by Goldstein, who reports 7.1 per cent of male
mandibles with carious teeth as compared with 6.0 per cent
of female mandibles. I n explanation of this unusual condition-the lower incidence of caries among Eskimo femalesTABLE
__
3
Inetdence of canes 'In relation t o sex
II
__
NUNBER
- _.__- _ _ _ _ _
Males :
5 to 20 years
94
21 years and above
71
Total, males
(165)
Females :
5 to 20 years
78
21 years and above
53
Total, females
(131)
-
I
-
-
'-I NumberCARlES
I Percent
C R O ~ D E DTEETH
-. .. __
Number
Per cent
34.0
19.7
(27.8)
17
6
(23)
18.1
8.5
(13.9)
29.5
18.9
(25.2)
17
6
(23)
21.8
11.3
(17.6)
~
i
32
'
I
14
1
(46)
I
I
,
j
23
10
(33)
1
i
the theory might be advanced that the common practice of the
Eskimo women of softening hard skins by chewing might be
responsible, through the additional exercise given the teeth.
But the age distribution does not seem to bear out such a n
explanation, for the adult females, who use their teeth most
extensively in this way, show almost a s high an incidence of
caries (18.9) a s do the adult males (19.7), while a greater
sex difference, 29.5 for the females a s compared with 34.0
for the males, is found among the subadults who do little or
no skin chewing. The relation between skin chewing and
dental conditions among the Eskimo is sometimes overemphasized, especially in regard to attrition of the teeth ; the coarse,
460
HENRY B. COLLIXS, JR.
heavy food, and particularly the considerable amount of sand
it often contains, is sufficient to account for the condition of
extreme wear so characteristic of the teeth of all Eskimo
adults, both male and female.
I n contrast t o their somewhat lower susceptibility to caries,
the females of both age groups show a higher percentage of
crowded teeth than do the males.
COMPARISON O F U P P E R AND LOWER TEETH
The teeth of the lower jaw were found t o be more susceptible to caries than those of the upper jaw, and the molars were
affected to a far greater extent than the other teeth. The
molars were affected in the following order : lower first, lower
second, upper first, lower third, upper second, upper third.
This sequence is exactly opposite to that recorded by Goldstein, who found that the first, second, and third mandibular
molars were progressively affected. However, the fact that
such a large number of the living Eskimos examined were
children accounts for the relative scarcity of carious third
molars in the present series.
co~cLusIo~
I n view of the incomplete dental examination and the relatively small number of individuals examined, too much weight
should not be attached to the sex and age factors, nor to the
difference in susceptibility of the two jau7s. As stated before,
a more thorough and technical examination would certainly
reveal a somewhat higher percentage of caries than is here
reported. The significant point is that even the examination
that was made shows caries to have increased materially
among the Eskimo since they have come into contact with
civilization. And since their food habits are known to have
changed to a greater o r less extent, there can be no doubt
that diet is the predisposing factor primarily responsible
for the increasing prevalence of dental caries in the present
population, whatever may have been the immediate cause or
causes leading to the actual production of the carious lesions.
CARIES A K D CROWDING I N TEETH O F ESKIMO
461
F o r as long as the Eskimos adhered to their native diet, consisting mainly of sea mammals and fish, rich in the essential
food elements and requiring hard usage of the teeth and jaws,
dental decay and crowding of the teeth were practically
unknown. This was true of the Eskimos as a whole prior
to white contact a n d i t is true to-day of those living at the
more remote settlements where civilized food is not obtainable. On the other hand, deterioration of the teeth begins
when the native diet is supplemented by soft manufactured
foods, and increases i n direct proportion to the extent that
these a r e consumed. There is no occasion to enter here upon
the question of whether the observed cases of caries have
been produced through the local action of these unaccustomed
foods on the teeth or whether the use of such foods led to a
dietary imbalance which prevented the formation of enamel
of caries-resistant type. However, assuming diet t o be the
principal causal factor involved, it should be noted that caries
has appeared not only where the native diet has been practically replaced by civilized foods, as at Nome, but also to a
lesser extent 011 St. Lawrence and King Islands, where such
foods have merely supplemented the native diet.
SUMMAHY
1. Examination of the mouths of 296 Alaskan Eskimos
showed that 26.7 per cent had one or more carious teeth and
that 15.5 per cent had crowded teeth. These percentages on
the living a r e considerably higher than those reported for
the prehistoric Eskimos, and apparently a r e to be attributed
to changed food habits following contact with white civilization. Race mixture does not seem to have been a factor.
2. Caries and crowded teeth a r e much more frequent among
the Eskimos living a t white settlements or having access to
civilized foods than among those at the more remote scttlements where there is little contact with whites.
3. According to age, the individuals were affected in the
following order : adolescents, young adults, young children,
and older adults.
462
HEh’RY B. COLLINS, JH.
4. The males, both young and adults, showed a slightly
higher incidence of caries and a lower incidence of crowded
teeth than the females.
5. The teeth of the lower jaw were more carious than those
of the upper jaw. Lower first molars were the most frequently affected, followed by the lower second, upper first,
lower third, upper second, and upper third.
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