Bush, Leslie L. (Glenn A. Black Laboratory of Archaeology, Indiana University,
Bloomington)
HUMAN DENTITION FROM THE BOWEN SITE, 12 MA 61
The Bowen site was a late prehistoric habitation site located on the West Fork
of White River northeast of Indianapolis. While there were at least two late prehistoric
occupations of the site (R. G. McCullough, A Reanalysis of Ceramics from the Bowen
Site: Implications for Defining the Oliver Phase of Central Indiana. M.A. thesis,
Ball State University, 1991), none of the burials were accompanied by goods indicating
their cultural affiliation. Therefore the human remains as a group should be thought
of as representing a conglomeration of cultures which are similar, though not
identical.
In studying the Bowen dentition, only individuals from clear burial contexts were
examined. (There were remains from a minimum of 20 other individuals found on
the site). Of the 39 burials, 23 had reasonably complete permanent dentitions.
The 23 represent 12 females, 7 males, and 4 juveniles which were too young to
determine sex. The males present were, in general, far older than the females,
having a mean age of 52.3 years as opposed to the mean female age of 35.1 years.
(The difference is significant at p<=,02.) As John Dorwin noted, young men were
presumably more likely to die hunting or fighting away from the village and were
buried where they died (The Bowen Site: An Archaeological Study of Culture process
in the late Prehistory of Central Indiana. Indiana Historical Society, Prehistory
Research Series 4(4), 1971.)
Four traits were scored for this study: number of dental caries, amount of calculus,
amount of molar wear, and presence of linear enamel hypoplasia.
Only those caries large enough to admit a dental probe were scored, to avoid falsely
identifying spots on teeth that are the result of postmortem events rather than
caries. As is typical of Ft. Ancient populations, all 23 individuals examined
had caries; 36.9% of the teeth at Bowen were carious. Males at Bowen had significantly
higher caries rates than did females -- 52.2% as opposed to 31.3%. The most likely
explanation for this difference is simply the demographics of the sample from
the Bowen site, since caries are highly correlated with age in human populations.
Dental calculus or tartar was scored according to Brothwell's method (in Simon
Hillson 1986 Teeth, Cambridge University Press). Occasionally, food debris becomes
incorporated in calculus, meaning that plaque hold the potential to allow us to
recover food remains directly.
Sixty-five and two tenths percent of individuals and 22.7% of teeth displayed
at least some calculus. Most of it fell into the slight category, with some moderate,
and no tooth scored as heavy. Men had a slightly higher percentage of teeth with
calculus than did women, but the difference was not statistically significant.
Studies of modern populations have found a strong correlation between calculus
and age. Here the correlation coefficient was only .15. The most likely explanation
for this seems to be a loss of calculus in the field or during curation since
it is fairly easy to dislodge during cleaning. It seems therefore that any information
that comes from calculus at Bowen will most likely be in the form of recovered
microscopic food remains.
Attrition, or amount of wear, was scored using Thomas Murphy's method ("Gradients
of Dentine Exposure in Human Molar Tooth Attrition", American Journal of Physical
Anthropology 17:179-86, 1959.) A difference in categories (or wear gradient)
of 1 was both the median and mode for mandibular and maxillary first and second
molars. The maxillary molars had many more wear gradients in the 2 and 3 categories
than did the mandibular molars (9 as opposed to 3 in the mandible). This is a
typical finding, since teeth in the lower jaw tend to wear faster than those in
the upper jaw in human populations. There was no correlation between molar gradient
and age. Women's teeth in general appear to wear more slowly than men's teeth,
but the difference was not statistically significant.
Linear enamel hypoplasia (LEH) was scored simply as present or absent. LEH appears
as horizontal grooves or pits on the teeth, especially on the cheek or lip side
of the crown. It represents a general indication of stress or growth disruption
during the time that tooth enamel is being formed.
At Bowen, 91.3% of individuals and 34.1% of teeth exhibited some degree of LEH.
The incidence of LEH at Bowen seems rather high. Much of the LEH noted at Bowen
could be characterized as "slight" and so some of it may not in fact be pathological
indicators of stress or growth disruption but rather part of the normal dental
variation in that population. On the other hand, Mahmoud El-Najjar's work indicates
that hereditary LEH is characterized by the presence of vertical bands of good
enamel ("Prevalence and Possible Etiology of Dental Enamel Hypoplasia", American
Journal of Physical Anthropology 48:185-92, 1978). This was not noted in teeth
at Bowen, indicating that further study of stress and growth disruption in the
post-cranial material at Bowen must determine whether or not the LEH observed
truly represents growth disruption or stress.
In women, 36.8% of teeth exhibited LEH while only 13.8% of men's teeth showed
the abnormality. The difference is statistically significant at p<=.02. If the
LEH is part of the normal range of variability in those populations, it may have
a genetic component that makes it more likely to show up in females. If the LEH
represents growth disruption, then this finding indicates that girls were more
stressed by poor nutrition or disease than were boys. There was no correlation
between LEH and age at Bowen.
Finally, an attempt was made to identify dental differences among individuals
from each of the four burial clusters at the Bowen site. Bret Ruby's flouride
dating of the burials indicated that the northern area was in use earlier than
the other areas ("Flouride Dating of Human Bone from the Bowen Site (12 Ma 61),
Marion County, Indiana" ms. on file, Glenn A. Black Laboratory, 1990). ANOVA analysis
produced no significant differences among burials from different clusters -- at
least for the four traits scored in this study. It seems that the diet was similar
enough in all peoples using the site that differences in dentition cannot be detected.
In sum, the dental evidence is consistent with the current view of a Ft. Ancient
or late prehistoric diet based on hunting and cultivation of tropical cultigens.
That the incidence of both caries and linear enamel hypoplasia appear higher than
might be expected indicates that further study of nutritional stress in the Bowen
population should prove revealing. [return to 1992 abstracts menu][continue to next]