Relationship Between the Severity of Malocclusion and Oral Health Related Quality of Life: A Systematic Review and Meta-analysis

Purpose: To investigate the impact of untreated malocclusion on different aspects of oral health-related quality of life (OHRQoL). Materials and Methods: All relevant literature published up to February 18, 2016 was collected from nine electronic databases. To make studies comparable, studies that used the dental aesthetic index (DAI), index of orthodontic treatment need (IOTN), or index of complexity, outcome and need (ICON) to measure malocclusion and oral health impact profile (OHIP) to measure OHRQoL were selected for systematic review. Meta-analysis, two independent-samples t-test and binary logistic regression were used to test whether different malocclusion severity groups had different OHIP scores. Results: A total of 564 non-duplicate publications were identified first. Of these, 13 studies were included in this review. All studies had a cross-sectional design and most of them used convenience samples. Eleven studies presented a significant result about the association of malocclusion and OHIP scores. Statistical analyses showed that malocclusion had an impact on all subscales scores, and more severe malocclusion indicated higher OHIP scores on the subscales of physical disability, physical pain, psychological discomfort, psychological disability, and social disability. Conclusion: Untreated malocclusion was significantly associated with OHRQoL. The more severe the malocclusion, the worse was the impact on some physical domains and all psychosocial domains of OHRQoL. There was a lack of longitudinal population-based studies to confirm this result.