Family history and oral health: findings from the Dunedin Study.

CONTEXT

The effects of the oral health status of one generation on that of the next within families are unclear.

OBJECTIVES

To determine whether parental oral health history is a risk factor for oral disease.

METHODS

Oral examination and interview data were collected during the age-32 assessments in the Dunedin Study. Parental data were also collected on this occasion. The sample was divided into two familial-risk groups for caries/tooth loss (high risk and low risk) based on parents' self-reported history of tooth loss at the age-32 assessment interview.

MAIN OUTCOME MEASURES

Probands' dental caries and tooth loss status at age 32, together with lifelong dental caries trajectory (age 5-32).

RESULTS

Caries/tooth loss risk analysis was conducted for 640 proband-parent groups. Reference groups were the low-familial-risk groups. After controlling for confounding factors (sex, episodic use of dental services, socio-economic status and plaque trajectory), the prevalence ratio (PR) for having lost 1+ teeth by age 32 for the high-familial-risk group was 1.41 [95% confidence interval (CI) 1.05, 1.88] and the rate ratio for DMFS at age 32 was 1.41 (95% CI 1.24, 1.60). In the high-familial-risk group, the PR of following a high caries trajectory was 2.05 (95% CI 1.37, 3.06). Associations were strongest when information was available about both parents' oral health. Nonetheless, when information was available for one parent only, associations were significant for some outcomes.

CONCLUSIONS

People with poor oral health tend to have parents with poor oral health. Family/parental history of oral health is a valid representation of the intricacies of the shared genetic and environmental factors that contribute to an individual's oral health status. Associations are strongest when data from both parents can be obtained.