Impact of Malocclusion on Quality of Life among Young Adults

Objective: To determine the impact of malocclusion on people's oral health-related quality of life (OHRQoL). Methods: A cross-sectional study involving 273 young adults seeking orthodontic care. OHRQoL was assessed by the short form Oral Health Impact Profile (OHIP-14) and United Kingdom Oral Health-related Quality of Life measure (OHQoL-UK). Orthodontic treatment need were assessed from study casts by: Dental Aesthetic Index (DAI), Index of orthodontic Treatment Need (IOTN) - Aesthetic component (IOTN-AC) and Dental Health Component (IOTN-DHC) and Index of Complexity, Outcome and Treatment Need (ICON). Variations in OHIP-14 and OHQoL-UK were determined with respect to orthodontic treatment need and the magnitude of differences was calculated (Effect Size: ES). Results: There were significant but weak correlations between occlusal indices scores and OHIP-14 scores (P<0.05, r<0.3) and between occlusal indices scores and OHQoL-UK scores (P<0.05, r<0.4). The magnitude of the statistical difference in OHQoL-UK scores was moderate to large (ES: 0.50 to 0.85), and largest when DHC (ES= 0.85) and ICON (ES=0.71) were used. The magnitude of the statistical difference in OHIP-14 scores was relatively lower (ES: 0.22 to 0.65), but also greatest when DHC and ICON were used to determine treatment need (ES 0.50 and 0.65 respectively). Conclusion: Orthodontic treatment need was associated with OHRQoL. The magnitude of the statistical difference between those with and without an orthodontic treatment need was larger when OHRQoL was assessed using OHQoL-UK compared to OHIP-14. DHC and ICON were more useful indices in identifying greater differences in OHRQoL with respect to orthodontic treatment need.