Relationship between orthodontic treatment and dental caries: results from a national survey

Orthodontic treatment has been suggested to increase the risk of dental caries. The aim of this study was to evaluate the association between orthodontic treatment and the likelihood of dental caries.

The study included data for adults aged ≥ 19 years who participated in the Korea National Health and Nutrition Examination Survey in 2013-2015. The participants' demographic, socio-economic, and general and oral health-care data were collected by trained interviewers using a structured questionnaire. The number of decayed teeth (DT) and the decayed, missing and filled teeth (DMFT) index score on oral examinations performed by dentists were compared between subjects who underwent orthodontic treatment and those who did not, using the chi-squared test and logistic regression analysis.

All logistic regression analysis models showed a significant association between orthodontic treatment and untreated dental caries. The likelihood of having untreated dental caries was lower in subjects who had received orthodontic treatment than in those who had not, regardless of confounding factors (P < 0.001). After adjustment for confounding factors, the mean number of DT was lower in subjects who had received orthodontic treatment than in those who had not (0.66 vs. 0.94; P < 0.001). There was no statistically significant difference in the DMFT index score between the two groups.

Orthodontic treatment was associated with a decreased likelihood of untreated dental caries. Moreover, there was no evidence indicating a link between the DMFT index score and orthodontic treatment.