Malocclusion and oral health-related quality of life among young Danish adults. Is there a difference between subjects who received orthodontic treatment during adolescence and subjects without treatment need? A cross-sectional study

To evaluate and compare malocclusion traits and oral health-related quality of life (OHRQoL) between untreated young adults assessed to have no orthodontic treatment need during childhood, and young adults treated orthodontically during childhood. In addition, to investigate the relationship between malocclusion and OHRQoL. One hundred undergraduate students were screened for eligibility. Subjects had intraoral scans and completed OHIP-14 questionnaires. Angle molar relationship, overjet, overbite, arch length and width, Little's Irregularity Index (LII), Peer Assessment Rating (PAR) index and Dental Aesthetic Index (DAI) scores were assessed. Unpaired t-tests were used to compare outcomes between treated and untreated subjects. Multiple regression analyses were conducted to model the relationship between OHIP-14 and several prognostics simultaneously. Ninety-six subjects were included (mean age ± SD = 23.7 ± 1.8 years): 41 treated and 55 untreated. The untreated subjects had significantly higher LII (<i>p</i> = .02), PAR (<i>p</i> = .01), DAI (<i>p</i> p = .03). The treated subjects had significantly larger inter-canine and inter-premolar distances. No relationship was found between OHIP-14 and LII, PAR, DAI, age, gender and presence/absence of previous orthodontic treatment. However, the DAI score was significantly correlated with the OHIP-14 functional limitation domain. Untreated subjects had significantly higher LII, PAR and DAI scores than the treated subjects. DAI score was significantly correlated with the OHIP-14 functional limitation domain.