Background <p>Considering that the association between socioeconomic status (SES) and oral health status differs by sex, we examined the impact of factors such as education, economic status, employment type, and social support on tooth loss in dental patients attending clinics, separately for men and women.</p> Methods <p>This study was based on a survey of dental patients across Japan conducted by the Foundation for the Promotion of 8020 between 2014 and 2019. To determine sex differences in the association between number of teeth lost and SES, a modified Poisson regression analysis was performed with the number of lost teeth during 5 years as the dependent variable. The ratio of means (RM) was calculated separately for men and women.</p> Results <p>In total, 1,355 participants were included in the analysis. Among women, those with fewer years of education or temporary employment had a significantly higher RM for tooth loss. Moreover, women with a higher subjective economic status or more social support had a lower RM for tooth loss. In contrast, there was no significant association between SES and tooth loss among men.</p> Conclusions <p>The association between tooth loss and SES differs by sex. Preventive strategies should consider SES-related sex differences in oral health.</p>