Associations between Malocclusion and Oral Health-Related Quality of Life among Mongolian Adolescents

Malocclusion may affect oral health-related quality of life (OHR-QoL), however, the previously detected associations were affected by confounding factors. We hypothesized that there is indeed an association between OHR-QoL and malocclusion and investigated in a population-based study of 420 Mongolian adolescents mean age: 12.6 (standard deviation (SD) = 1.09) years from two secondary schools, located in an urban and a suburban area. We randomly selected two classes from each school. The Index of Orthodontic Treatment Need (IOTN) was used to assess malocclusion. OHR-QoL was assessed using the Child Perceptions Questionnaire (CPQ). Multivariate analysis was used to determine whether malocclusion had an independent effect on OHR-QoL. Overall, the existence of any type of malocclusion was not significantly associated with CPQ results. However, increased overjet was significantly associated with oral symptoms (coefficient: 0.66, 95% CI: 0.14-1.19), functional limitations (coefficient: 0.62, 95% CI: 0.17-1.08), and social well-being (coefficient: 0.50, 95% CI: 0.06-0.93). Deep bite was also significantly associated with oral symptoms (coefficient: 0.54, 95% CI: 0.23-0.84) and functional limitations (coefficient: 0.45, 95% CI: 0.19-0.72). Although malocclusion per se was not significantly associated with OHR-QoL, specific types of malocclusion, i.e., increased overjet and deep bite, were associated with OHR-QoL.