The influence of orthodontic treatment on dental caries: An Australian cohort study

Abstract

Objective To assess the influence of orthodontic treatment on long‐term caries experience in 30‐year‐old South Australians. The research hypothesis that was tested was that those with previous orthodontic treatment would have lower caries experience. Methods In 2005‐2006, a sample of 1859 30‐year‐olds from Adelaide, South Australia, who comprised 47% of participants who had previously taken part in an oral epidemiology study in 1988‐1989, were traced from the Australian electoral roll and invited to participate in a cross‐sectional study investigating long‐term dental health outcomes. Participants completed a questionnaire that collected information on socio‐demographic characteristics, dental health behaviours and receipt of orthodontic treatment. This was followed by clinical examination. The outcome variables were the summed decayed, missing and filled teeth (DMFT) score, and its individual components. Data were analysed using negative binomial regression. Results The response rate for the questionnaire was 34% (n = 632). There were no systematic differences between those who were followed up and those who were not followed up. Clinical data for 448 participants were available for analyses, representing 24% of the originally contacted individuals. By the age of 30, over a third of participants had received orthodontic treatment. Regardless of initial malocclusion classification, orthodontically treated participants had a lower DMFT score at age 30 but this did not reach statistical significance. Adjusted models controlling for socio‐demographic, dental health behaviour and malocclusion status showed no associations between orthodontic treatment and decayed (Exp B: 1.00, 95% CI: 0.72‐1.40), missing (Exp B: 1.00, 95% CI: 0.59‐1.69), or filled teeth (Exp B: 1.18, 95% CI: 0.93‐1.51) or overall DMFT (Exp B: 1.12, 95% CI: 0.88‐1.41). Conclusion There was no difference in the long‐term caries experience of South Australians aged 30 years based on past orthodontic treatment. Our study does not support the contention that those treated orthodontically have better dental health later in life.

The long‐term influence of orthodontic treatment on adults’ psychosocial outcomes: An Australian cohort study

“…After exclusion of invalid study identification numbers as well as individuals who were traced erroneously, data for 448 participants were available for analysis, representing 24% of the original study participants. There were significantly more female participants in the long‐term study, as well as participants who came from a household not having a health care card, or where both parents were educated at tertiary level . High internal consistency ratings were found for each of the instruments used to assess the psychosocial outcomes, with the coefficient alpha being: GSES, 0.88; PHCS, 0.85; MSPSS, 0.92 and LOT, 0.85.…”

“…Clinical factors such as the exact nature of orthodontic treatment received, achievement (or otherwise) of treatment objectives and retention/relapse were beyond the scope of this study. Sex and receipt of orthodontic treatment (ie fixed orthodontic treatment) were coded dichotomously . Tooth brushing was coded as “0‐13 times per week” and “more than or equal to 14 times per week,” with the latter being equivalent to brushing at least twice a day .…”

“…Sex and receipt of orthodontic treatment (ie fixed orthodontic treatment) were coded dichotomously . Tooth brushing was coded as “0‐13 times per week” and “more than or equal to 14 times per week,” with the latter being equivalent to brushing at least twice a day . Income per annum was also coded dichotomously as <$AUD80 000 and ≥$AUD80 000.…”

“…Income per annum was also coded dichotomously as <$AUD80 000 and ≥$AUD80 000. Education level and last dental visit were grouped into tertiles …”

“…A comparison of characteristics of participants in the baseline and long‐term study was performed in order to elucidate any difference in their representativeness . Internal reliability for each outcome variable was measured using Cronbach's alpha.…”