Objective To determine whether dental caries, as an indicator of cumulative exposure to sugar, is associated with the incidence of acute rheumatic fever and chronic rheumatic heart disease, in Māori and Pacific children aged 5 and 6 years at their first dental visit.

Materials and methods A cohort study was undertaken which linked school dental service records of caries with national hospital discharge and mortality records. Cox models were used to investigate the strength of the association between dental caries and rheumatic fever incidence.

Results A total of 20 333 children who were free of rheumatic heart disease at enrolment were available for analysis. During a mean follow-up time of 5 years, 96 children developed acute rheumatic fever or chronic rheumatic heart disease. After adjustment for potential confounders, children with five or more primary teeth affected by caries were 57% (95% CI: 20% to 106%) more likely to develop disease during follow-up, compared to children whose primary teeth were caries free. The population attributable to the risk for caries in this cohort was 22%.

Conclusions Dental caries is positively associated with the incidence of acute rheumatic fever and chronic rheumatic heart disease in Māori and Pacific children. Sugar intake, an important risk factor for dental caries, is also likely to influence the aetiology of rheumatic fever.