Erratum

After the publication of this work [1], we became aware that the total number of being “unmarried” in Table 1 was incorrect. In the Norwegian study, marital status was originally categorized as (1) married, (2) unmarried, (3) divorced and (4) widowed. For the purpose of analysis, the variable was dichotomized as (1) married (including the original category 1) and (0) unmarried (including the original categories (2,3), whereas the original category (4) was set to missing instead of correctly being included into the unmarried category of the dichotomy variable. This error has been corrected in a revised Table 1 included in this erratum. The new categorization of the variable marital status did not influence the results and conclusion of the article. We regret any inconvenience that this inaccuracy might have caused.

Table 1 Socio-demographics and oral health status at baseline according to follow-up status in Norway and Sweden