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.