A spectrum from MH to MIH occurred. The MHSI characteristics were predictive of the treatment of affected FPMs and can guide management.

High disease levels were observed. Age, socio-economic status and enamel defects were associated with caries experience, not severity of cardiac diagnoses. Early referral for dental care and improved access should be facilitated.

Assessments of oral health status were often deferred until immediately prior to cardiac surgery despite the cardiologist's perception that children with cardiac defects were at increased risk of oral disease and prior experience of surgical cancellation due to oral disease. Paediatricians may need to facilitate early oral assessment for these children.