The Visceral Adiposity Index (VAI) is a gender-specific measure of body fat distribution and function, strongly associated with metabolic diseases such as insulin resistance, cardiovascular diseases, and certain cancers. However, its relationship with oral health remains insufficiently explored. This study analyzed data from the 2009-2014 National Health and Nutrition Examination Survey (NHANES), including 3,938 participants, to investigate the association between VAI and oral health, as well as the potential mediating role of the Systemic Immune-Inflammation Index (SII). Multivariate logistic regression analysis revealed a significant positive association between higher VAI and poorer oral health (β = 0.02, 95% CI: 0.00-0.03, P < 0.05). In contrast, among the elderly population, VAI was negatively correlated with the severity of periodontitis (β = -0.03, 95% CI: -0.07-0.00, P < 0.05), with this relationship remaining significant after adjustment for potential confounders. SII was not found to play a significant mediating role in this relationship. This study is the first to demonstrate a significant association between VAI and oral health, suggesting VAI as a potential indicator of oral health status. However, it is important to note that the study does not establish causal relationships, nor does it validate VAI as an independent diagnostic tool. Further research is needed to elucidate the underlying mechanisms and to assess the practical applicability of VAI in oral health management.