Masticatory performance in aging populations: A scoping review of research landscapes in Japan, Sweden, and India

Evidence suggests that masticatory function reflects overall well-being, particularly in an aging population. The present review aims to map and characterize the research landscape on masticatory function among older adults in Japan, Sweden, and India, focusing on study designs, assessment methods, outcomes, and publication patterns to identify gaps and highlight methodological diversity across countries. A systematic search was conducted, which identified 51 articles, with the majority originating from Japan (n = 44). Cross-sectional study designs were predominant (n = 35), with various methods used for assessing masticatory function. The majority of studies investigated systemic health outcomes (n = 24), particularly frailty and nutrition, while others focused on associated factors (n = 13), intervention effects (n = 4), or methodological validation (n = 3). The review revealed that most studies originated from Japan, with relatively limited evidence from Sweden and India, highlighting gaps in cross-national research. A variety of assessment methods and outcomes were used, and recent studies increasingly emphasize the role of masticatory function in overall health. By proposing masticatory performance as a holistic health marker, this review emphasizes its relevance as an indicator of health inequality in aging populations across diverse settings.