Sex difference in oral disease of millet agriculturalists from the Take-vatan lineage of the recent Bunun tribe of Taiwan

Abstract

Biological anthropologists have repeatedly demonstrated a sex difference of caries prevalence in past societies and have often ascribed this difference to cultural factors related to the sexual division of labor, as well as to biological factors stemming from the female reproductive function. Even though archaeological and historical evidence can hint at the prevailing living conditions, they are not detailed enough to confirm the cultural factors influencing oral disease. For this, skeletal remains in which the prevailing subsistence patterns have been documented by cultural anthropologists must be studied. This study demonstrates sex-specific oral disease prevalence (caries, antemortem tooth loss, periapical abscess, alveolar resorption, and calculus accretion) as well as degree of dental attrition, using the recent Bunun skeletal assemblage, one of the Taiwanese aboriginals. During Japanese rule, cultural anthropologists recorded that the staple product of the Bunun tribe was foxtail millet. Males were responsible for cultivation and hunting, while females were responsible for gathering and preparing foods. The results of this study showed the relatively high morbidity of oral disease, except periapical abscess, regardless of sex. The frequency of females suffering caries and alveolar resorption was significantly greater compared to that of males, and the inverse was true for calculus. Taking into account the fact that the Bunun tribe depend greatly on vegetable foods and smoke heavily, their high morbidity of oral disease is understandable. The combination of their higher morbidity in alveolar resorption and calculus is comparable to the Southeast Asian groups chewing betel nuts documented in previous studies. The sex-specific caries prevalence is believed to be related to the Bunun's typical and strict sexual division of labor. The inconsistency of the sex difference patterns between alveolar resorption and calculus might be related to the multifactorial origin of the alveolar resorption.

A sub-continent of caries

“…Many of them would have relied on grain foods or pastoralism, i.e., the latter peoples often trade with agriculturalists for grains made into sticky porridge (Forde & Jones, 1950;Skinner, 1973). The naturally high cariogenicity of corn and wheat (Dodds, 1960;Okazaki et al, 2013) combined with the sticky nature of the grain porridge potentially contributes to higher instances of caries in savanna dwellers.…”