The potential role of dental function in TMJ osteoarthritis is examined in an ancient British population. Human skeletal remains from five archaeological sites in England (n = 369) were studied to assess the associations between the presence of osteoarthritis and dental function variables, in particular antemortem tooth loss and dental attrition. Individuals aged over 17 years with at least a portion of either the left or right TMJ were included in the study. Each individual was scored for the occurrence of arthritic lesions on the mandibular condyle and glenoid fossa, the level of dental attrition, and antemortem tooth loss. A loglinear analysis was performed with osteoarthritis as the dependent variable and tooth loss, attrition, sex, and age as the independent variables. Tooth loss and sex are not significantly associated with TMJ osteoarthritis when attrition and age are included in the analysis. Attrition is significantly associated with osteoarthritis even when the analysis corrects for age. The significant association of attrition with osteoarthritis suggests that dental functions may have an influence, separate from ageing, on the development of TMJ osteoarthritis.

Many studies involve comparison of measures of sexual dimorphism between two samples. This comparison is used to test a variety of hypotheses, such as changing environmental conditions. Methods for testing the significance of the difference between two populations tend to be complex, and/or require access to complete original data. We offer a simplified approach which is based on a linear regression model using dummy variables. Our method is computationally simple and can be used with summary statistics (sample size, means, standard deviations) instead of raw data. We present three examples of the application of our method to problems in physical anthropology. We also note that our method has a broader range of applications apart from that of sexual dimorphism.

The effects of agricultural intensification on health are examined in prehistoric populations of the Valley of Oaxaca, Mexico. Agriculture was practiced in the Valley of Oaxaca by the beginning of the Early Formative period (ca. 1400 B.C.), and had intensified by the Late Formative (ca. 500 B.C.). Skeletal remains from 14 archaeological sites in the Valley are pooled by temporal affiliation into a nonintensive agriculture group (1400-500 B.C.) and an intensive agriculture group (500 B.C.-1400 A.D.). The health effects of agricultural intensification are assessed by comparing the frequency of periosteal reactions, cribra orbitalia, and enamel hypoplasia between the intensive and nonintensive agricultural groups. Overall, no significant differences (alpha = 0.05) are found between the nonintensive and intensive groups. Power analyses of the chi-square tests indicate that the tests have a high probability of rejecting a false null hypothesis. The intensification of agriculture does not appear to have had a deleterious effect on the health of the prehistoric population of the Valley. The differences between this study and previous studies of health and agricultural development may be explained by differences between the processes of intensification and development or by differences between primary and secondary centers of agricultural development.

The location of enamel hypoplastic defects on the tooth crown has been used to determine the age of an individual at the time the defect-producing stress occurred. The assumptions made in following this methodology are examined, and one in particular, that tooth size variation has a minimal impact on ageing and subsequent chronological distributions, is tested. Teeth with no occlusal or minimal wear and with enamel hypoplasias were measured for crown height and the location of the defect on the crown. Two samples are used, one comprising a series of archaeological specimens and the other from modern clinical extractions. The chronological distributions of the defects are determined by three different methods: one is based on a tooth mineralization chart; the second method uses the same chart but incorporates individual crown heights; and the third method adjusts the chart for the sample's mean crown heights. Significant differences between the age estimates are observed in both the modern and archaeological samples. Tooth size does affect the ageing of hypoplastic defects and the chronological distributions. By adjusting the mineralization chart for the sample's mean crown heights, the significant differences in age estimates can be corrected.

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