Cultural and Social Determinants of Indigenous Peoples' Health: Understanding Oral Health Inequities in Canada, New Zealand/Aotearoa, and Australia

OBJECTIVE: This cross-sectional study examined the cultural and social determinants of health in Canada, New Zealand, and Australia and their relevance to the oral health of Indigenous pregnant women. METHODS: An Indigenous framework was applied to a social determinants of health (SDH) model, Charlotte Loppie's Tree Metaphor, utilising data from the Baby Teeth Talk Study, a multi-national academic-community partnership, to compare SDHs among Indigenous pregnant women in Canada (n = 544), New Zealand (n = 222), and Australia (n = 446). The same survey instrument, with cultural adaptations, was used. Self-rated oral health and the oral health impact on dimensions of quality of life were assessed. 'Stem' SDHs included socio-demographic characteristics, lifestyle practices, oral health literacy, knowledge of children's oral hygiene, value of oral health self-care, psychological stress, sense of mastery, social support, oral health self-efficacy, and fatalism. 'Core' SDHs included dental care access and Indigenous cultural identity. The 'Root' SDH was self-reported interpersonal racism. Z-tests for the comparison of means and the Normal approximation to the Binomial distribution for proportions were used with statistical adjustment for multiple pairwise comparisons. RESULTS: The participants' mean age was not statistically different across the countries. Maternal rating of their oral health as 'fair/poor' was significantly higher in New Zealand (57.7%) and Australia (54.3%) than in Canada (39.0%). First Nations/Métis expectant women in Canada were twice as likely to have visited a dentist in the last year, and least likely to report cost as a barrier to care. They also experienced less racism. Pregnant Māori women had higher oral health literacy, greater knowledge of children's oral hygiene and greater oral health self-efficacy. Employment income and social support were greatest among Māori women. Aboriginal women in Australia faced more unfavourable SDHs, particularly those related to socio-economic status. One-in-three First Nations, Māori and Aboriginal women perceived culture and ethnicity as central to their identity. CONCLUSIONS: Differences in governance, funding, and delivery models for Indigenous oral healthcare can explain disparities in access to dental care for pregnant Indigenous women. Unique historical and cultural trajectories may account for the different SDHs of their oral health experiences, particularly those that are more distal and deeply rooted, such as discrimination and racism. Understanding how socio-cultural determinants differ among diverse Indigenous populations may, in turn, explain the differences in the effectiveness of some interventions (over others) in improving the oral health of Indigenous Peoples.