The nature and consequence of plaque trajectories

While the role of plaque in causing dental caries is fairly well understood, no research has explored the stability of plaque levels over a long period of time, or the association of plaque levels over time with oral health outcomes. Objectives: to report on plaque levels throughout childhood and into adulthood, and to investigate the extent to which differences may affect oral health outcomes. Methods: In a longstanding prospective cohort study of 1037 individuals born in 1972/73 in Dunedin (NZ), dental health data (including OHI-S scores) were recorded at ages 5, 9, 15, 18, 26 and 32. OHI-S data were available for 911 individuals at 3 or more points in time. Data were analysed using trajectory analysis to uncover the patterns of dental plaque across the lifecourse. Study members were categorised as having a 'good' (40.7%), 'moderate' (48.1%), or 'poor' (11.2%) oral hygiene trajectory on a maximum likelihood basis. Results: Some 34 (19.2%) low SES, 62 (10.7%) medium SES, and 6 (4.0%) high SES Study members had poor lifetime oral hygiene. After controlling for potential confounding variables such as gender, SES, smoking, dental visiting pattern, and fluoride exposure, by age 32 Study members with poor lifetime oral hygiene had: 5.1 times the odds of 1+ periodontal sites with 5+mm of attachment loss, 2.2 times more sites with bleeding on probing, were 4.4 times more likely to have lost teeth due to caries (with 5.3 times more teeth lost due to caries), and were nearly 4 times more likely to have untreated carious surfaces than those with a 'good' plaque trajectory. Conclusion: Distinctive plaque trajectory groups have been identified, and group membership is an important risk factor for oral health outcomes. Supported by the Health Research Council of New Zealand and NIDCR grant R01 DE-015260-01A1.