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Caries and attrition in the molar teeth of the Eskimo mandible.

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CARTES AND ATTRITION I N T H E MOLAR T E E T H O F
T H E ESKIMO MANDIBLE
MARCUS S. GOLDSTEIK
Division of Physical Anthropology, 17. 8. National Museum
A. CARIES
The subject of carious teeth has received a wealth of attention, largely it is true, on the etiology of the scourge, but
much also on its occurrence in the various groups of man.
A number of observers have noted the incidence of caries in
the Eskimo dentitions. Ritchie (’23, p. 64c) observed “not
the slightest trace of caries’’ in the teeth of thirty-one Eskimo
skulls; Hellman ( ’25) gives 12.5 per cent of eight crania:
Leigh (’25 b ) , only four out of 395 crania, or 1 per cent;
Martin (’as),2.5 per cent of Eskimo dentitions; and Drennan
(’29) tabulates 1.4 per cent of Eskimo with carious teeth.
The numbers of Eskimo crania examined by the above
authors, where given, are seen to be quite small. The only
exception is that of Leigh, where the teeth of 395 crania mere
observed. A much larger series than Leigh’s, representing a
greater geographical area, forms the basis for the present
study, although the lower jaws and molars only were. considered.
METHOD
Caries is defined in the present study a s a cavity, small or
large, caused by decay, or probable decay. Cases of pulp
exposure caused by attrition were not counted as caries.
Niches or hollows, which occurred especially in the third
molar, where obviously due to poor development of the crown,
also were not considered as caries. Although usually tiny
lesions, the caries were nevertheless nearly always plainly
discernible.
421
AAIERICAN J O C R I A L O F PHYSICAL ANTHROPOLOGY, VOL. XVI, NO. 4
APRIL-JUNE,
1932
422
MARCUS S. GOLDSTEIK
INCIDENCE OF MANDIBLES AFFECTED
Table 1 shows the percentage of Eskimos with carious lower
molars. This percentage, 6.6, is higher than that of any of
the previous observers, with the exception of Hellman.
Now HrdliEka (’09, p. 210), observing the dentition of the
Louisiana and Arkansas Indians states, “the first teeth
affected by caries, both in frequency and time, were the
molars,” and, in a later monograph on the Delaware Indians
(’16, p. 48), after making a similar statement, adds “especially in the lower jaw.” Leigh (’25a, p. 188) noted in the
Zuni Indians that the “second molar of the lower jaw was the
most susceptible” to caries, and (’23, p. 183) quotes HopewellSmith on Europeans thus: “By most writers the first
TABLE 1
Percentage of Eskimo mandibles uith carious molars
BPS
Males (366)
Females (385)
Unknown ( 5 6 )
_.__
1
E”,f,”l”,”,”,:
1
23
;
-
Total (807)
__
Children (29)
’
1-
’
4
1
-
PERCENT
6.0
1 -~ . . .
~
53
I
!
6.6
___-
:
9.5
~
mandibular permanent molar is believed to be the most frequently carious of all teeth.” I t seems, therefore, that the
teeth of the lower jaw, and especially the molars, a t least in
some peoples, are the most liable to caries. And since coinparaiively few Eskimo crania, particularly with lower jaws,
had been collected until four or five years ago, my larger
percentage of Eskimos with caries may be due to the examination of lower rather than upper jaws, as well as a much
greater number of specimens. There is also the possibility
that a part of my series may be a comparatively modern
group, which had perhaps subsisted more on white man’s
foods. Further, the discrepancy may be due to a difference
in method of observation or definition of caries. I n all events,
though the extent of caries in the Eskimo according to the
423
DENTAL CARIES AND ATTRITION IN THE ESKIMO
present paper is somewhat greater than has been recorded by
others, the Eskimo probably still enjoy the lowest racial
incidence of this disease.
S E X DIFFERENCES
Table 1likewise indicates that the males a r e somewhat more
prone to caries than the females. This condition appears
uiiusual ; the females of other peoples (Drennan, HrdliEka,
Leigh, et al.) a r e said to be more susceptible to caries than
the males, although such statements usually refer to the
TABLE 2
Caries of each mandibular molar ( E s k i m o )
__
.
Male
Female
Unknown
Child
.-
10
12
15
19
4
l
j
-
-~ -
Tot.al
_ _ .___.~
.
per
cent (both sides) :
Male
0.8'
Female
1.4
Per cent. (both sexes)
1
1.1
___ _ _ - Percentage derived from total
' Children excluded.
I
i
(622)
(639)
(13.53)*
I
1
1
8.4 (535)
2.0 (560)
2.3 (1159)
'
5.6 (394)
2.9 (380)
,
4.3 (794)
number of molars shown in parenthesis.
dentition as a whole. Considering the individual molars, the
females a r e more carious than the males in the first, but less
carious in the second and third (table 2). This difference
between the sexes in the molars affected is identical with the
observation of caries in the lower molars of Peruvian Indians
(Stewart, '31).
I S D I V I D U A L MOLARS AFFECTED
Table 2 presents the incidence of caries according to the
molar affected, also indicating the sex and side of jaw. It is
seen that the first molar is less frequently carious than the
second, and that the second molar is less affected than the
424
MARCUS S. GOLDSBEIN
third ; this molar sequence is the same in the two sexes. I t is
worth noting at this point that the caries was closely associated with the degree of attrition i n the teeth: the greater the
attrition, the more infrequent was the incidence of caries.
This fact probably explains the least incidence of the affection i n the first, a n d of its greatest occurrence in t h e third
molar, f o r attrition is most marked i n the first, decreasing in
order iii the second and third molars (p. 428). Indeed, Drennail ( ' 2 9 , p. 79) found exactly the same relationship between
attrition a n d caries in the African Bushmen, also remarking
that the lower third molar was the most carious of the whole
dentition.
Developmental defects on the occlusal surface of the molars,
especially the third, a r e common to all peoples, though probably to a lesser degree i n the case of the Eskimo. Such niches
a n d hollows a r e usually a predisposing factor in decay.
When, on the other hand, the progress of attrition opens u p
these pits, decay would seem to be arrested. Considering the
late eruption and back position of the third molar, however,
it is easily seen that in this tooth the decay originating in
developmental defects is not usually overtaken by attrition
a n d hence accounts f o r the higher incidence of caries here.
It should be remarked, moreover, i n the case of the Eskimo,
that even i n the third molar under these favorable conditions,
caries does not progress rapidly, rarely exceeding the size
of a pinhead.
LOCATION O F CARIES ON LOWER MOLARS
The location of the caries is given in table 3. The affection
was mainly between the fissures demarcating the cusps on
the occlusal surface. I n a few cases only was the affection
marked; i n many instances the caries was little more than
pin-point size. The center of the crown and buccal cusps
appear the most liable to the disease.
425
DENTAL CAEIES A K D ATTRITION IN T H E ESKIMO
ACCORDIKG TO GEOGRAPHICAL LOCALITY
I n table 4 are given the number of individuals affected and
their geographical locality. The classification of the main
divisions of the Eskimo is according to Hrdli6ka ( ’30). The
extent of caries is considerably greater in the Eskimo of the
south-midwest (8.4 per cent) than in those of the northwest
(3.8 per cent) and north-northeast (2.5 per cent). It must
be nokd, however, that St. Lawrence Island, geographically
and culturally, merges into the northwestern area, and might
reasonably be included in the latter division. Such a shift
TABLE 3
Location o f caries of Eskimo mandibular molars
~.
~.
,
.__.___
____
.-
FIRSTMOLAR
I
SECONDYOU&
~
1
TIIIRDMOLAR
TOTAL
Anterior
Posterior
Labial
Lingual
Center of crown
Anterior-labial
No record
-. Total
a
5
1
1
-
‘
1
~
j
8
-.
1
1
1
1
-
I
-
1 8 - 1
3
6
1
_..-
1 6 ,
.-
-.
I
19
._ _
_
I
_
~
77
.
-
Child.
of the St. Lawrence Island group would almost entirely
eliminate the difference in the incidence of caries between
the south-midwestern and northwestern Eskimo, although
these latter groups would still each show a substantially
higher prevalence of caries than the north-northeastern
Eskimo.
13. ATTRITION IN THE MANDIBULAR MOLARS O F THE
ESKIMO
METHOD
Leigh (’25 b) defines attrition as the “gradual wearing
away of the hard parts of the teeth through the physical and
TABLE 4
Eskimo mandibles with carious molars according to geographical locality
LOOALITY
South- and inidwest
St. Lawrence and Punuk
lslands
Kuskokwim River
Piunivak Island
___-______
I
I_ _Male
__
i
I
'emale S e x ?
-
-
~
'I_Total_'I- Male
44
I
Yukon River
27
10
Pastolik
Tanunuk (Nelson Island)
Rocky Point
'
8
Golofnin Bay
Koyuk and Norton B a y
5
Hooper Bay
7
P o r t Clarence
1
3
Muintrak
1 4
Cape Darby
Togiak
St. Michael Island
Kanakanak
I
1
1
Kulukak
Cape Denbigh
Cape Rornanzof
Cape Nome
Asiatic
Totals
I__
JAWS WITH CARIOUS MOLARS
OBSEBVED UANDIBLES
~
I
9
8 l
2 1
- 1
19
1
131
-
4
-1
--
- I
11
1
-- 1
- I
- '
3
-
31
2
--
I
-
d
i i
1 1
-
- I! - I' ,
-
-
8.4 1
Northwest :
Point Hope
Shishmaref
Wales
Konieruk
Point Barrow
Akeeveenuk
78
j
77
I
10
I 165
I
4
- I
Kntwhii~
Totals
Per cent of jaws affected
North and northeast:
Greenland
Cumberland Bay
Ungava Bay
Totals
P e r cent of jaws affected
-- Locality indefinite :
Alaska
Dnknown
.
426
-
I
-
1
-
I
-
-
-
D E S T A L C A R I E S A N D A T T R I T I O N IN T H E E S K I M O
427
physiological agencies of mastication of food. ” The Eskimo
make considerable use of their teeth in the preparation of
skins, as well as in the mastication of foods ip which sand
and grit a r e usually mixed. Teeth of adult Eskimo, therefore, especially the molars, might be expected to be, and they
are, quite worn. Leigh (’25 b ) has already written on attrition of teeth in the Eskimo. The data presented here, however, a r e more in detail and represent a much larger series
and wider geographical area. The molars of non-adults were
not included (except a few subadults which were sexed) ;
otherwise there was no selection. The observed wear is
recorded according t o the method used by Doctor HrdliEka:
slight wear, cusps showing a mere sign of abrasion; moderate
wear, dentine beginning to show (the cusps may be wholly or
not quite worn level, and the grooves may o r m ay not be
obliterated i n this type of wear) ;medium wear, dentine visible
011 the greater part of occlusal surface of tooth; marked wear,
all enamel on occlusal surface of tooth gone. This definition
of the degrees of attrition is essentially like that of Leigh.
RESULTS LXD DISCUSSION
The observations on degree of molar attrition a r e given in
table 5. In both sexes, the first molar is more worn than the
second, and the second more than the third.
The males present a n ideal distribution of attrition in the
first two molars; beginning with a small percentage of ‘no’
attrition, rising to a peak under ‘medium’ wear, and dropping
off somewhat in the extreme ‘marked’ wear. F o r the third
molar the highest percentage of wear is of the ‘moderate’
degree. I n the female series, however, a continuous upward
curve from ‘no’ to ‘marked’ wear obtains in the first molar,
while the second a n d third molars show the highest percentages in the ‘moderate’ column. I n short, the lower molars of
the females, even the first, manifest less wear than do those
of the males. This point is clearly seen when the percentages f o r the two sexes a r e compared. I n the first three (least)
degrees of wear, every female percentage is higher than the
-
32
-
R.
'
40
I1 -
L.
.9
- 18.-.
2.2
9.8
15.- .8.1
17.9
- -.
'er cent
-.
-.
R.
.,-
1
-
L.
-
30.4
57.1
24.9
-
I
-
65
26
98
13.7 ! 141
lpercent
I R.
-I---
__I-.
TABLE 5
Attrition of Eskimo mandibular molars
.-
114
78
35
. -
-
32.3
25.5
16,l
35.24.4
4.4.4
'er cent
- _.
a4
135
8Q
L.
DENTAL CARIES AKD ATTRITION IN THE ESKIMO
429
percentages representing like molars in the males ; in the last
two (marked) degrees of wear, every female percentage is
less than the corresponding percentages for the males.
This higher incidence of wear i n the teeth of the Eskimo
males is at variance with the research of Leigh ('25 b), who
found the female dentitions somewhat more subject to wear
than the male. The latter finding is what might be expected,
if this condition is attributed wholly to the chewing of hides,
which duty falls entirely upon the women. The front, rather
than the back teeth, would probably be used in skin chewing,
a n d this is likewise i n agreement with the fact that Leigh
observed the entire dentition. As ,already stated, a high content of grit is usually found i n the Eskimo diet and this is
likely the chief factor i n the molar wear of these people. It
is possible, on the other hand, that the present female series
as a whole represented a younger group than the males,
thereby accounting f o r their lesser molar attrition. I n all
events, the Eskimo, both male and female, show marked
attrition i n a substantial percentage of their lower molars.
SUMMARY
1. Represented by their mandibles, 6.6 per cent of Eskimos
were affected with carious molars. Caries in the Eskimo is
associated with degree of attrition: the greater the degree of
attrition in the lower molars, the less common was the occurrence of caries (see nos. 3 a n d 5 below). The Eskimo enjoy
probably the least incidence of caries of a n y racial group.
2. The lower molar teeth of the males were somewhat more
carious than those of the females.
3. The first, second, and third lower molars, in both sexes,
were increasingly affected by caries in the order given. The
carious affection was nearly always on the occlusal surface
of the crown; in few cases was the affection marked.
4. The incidence of caries was greater in the Eskimo of the
south-midwest than in the Eskimo of the northwest and northnortheast. However, the St. Lawrence Island Eskimo, considered more on geographical than somatic grounds, might
430
MARCUS S. GOLDSTEIN
be placed with the northwest group, thereby eliminating
practically altogether the difference between the south-midwest and northwest Eskimo. The north-northeast Eskimo
would still be less carious than the other groups.
5. The crowns of Eskimo mandibular molars were usually
very worn; this attrition was most marked in the first molar,
less in the second, and least in the third.
6. The lower molars of the female showed somewhat less
wear than those of the male.
LITERATURE CITED
DRENNAN, M. R. 1929 The dentition of a Bushman tribe. Ann. S. Afr. Mus.,
XXIV, 61-87.
HELLMAN,
M. 1925 Food and teeth. Dent. Cosmos, LXVII, 2.
HBDLICKA,A. 1909 Report on an additional collection of skeletal remains from
Arkansas and Louisiana. J. Acad. Nat. Sc. Phila., XIV.
1916 Physical anthropology of the Lenape or Delawares, and of
the eastern Indians in general. Bull. 62, Bur. Am. Ethnol., Washington.
LF~IQH,
R. W. 1923 Incidence of caries i n the different teeth and their respective surfaces. Military Dent. J., VI, 4, 183-194.
1925 a Dental pathology of Indian tribes. Am. J. Phys. Anthrop.,
V I I I , 2.
1925 b Dental pathology of the Eskimo. Dent. Cosmos, LXVII, 9,
884-898.
1928 Dental pathology of aboriginal California. Univ. Calif. Pub.
Am. Arch. and Ethn., X X I I I , 10.
MARTIN,R. 1928 Lehrbuch der Anthropologie. Jena.
RITCHIE, S. G. 1923 The dentition of the western and central Eskimos. Rep.
Canad. Arctic Exped., 1913-1918, X I I , C.
RUFFER, A. 1920 Study of abnormalities and pathology of ancient Egyptian
teeth. Am. J. Phys. Anthrop., 111, 3.
STZWAET,
T. D. 1931 Dental caries in Peruvian skulls. Am. J. Phys. Anthrop.,
x v , 2.
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