Malocclusion, orthodontic treatment, and the Oral Health Impact Profile (OHIP-14): Systematic review and meta-analysis

Objective:  To synthesize evidence on the impact of malocclusion and its associated treatment on people's quality of life across studies that used the Oral Health Impact Profile (OHIP-14) questionnaire in the adult population. Materials and Methods:  A systematic search of the English literature using Medline, PubMed, and EMBASE yielded 98 unique citations. Studies using OHIP-14 with individuals 15 years of age and older were included. After initial screening, 64 citations were excluded and another 9 were excluded after reading full text reports; the remaining 25 were included in the review. All studies were observational and used one of three study designs: 11 compared the same group before and after treatment (pre-post design), 10 compared groups with and without malocclusion (independent groups design) and four compared an orthodontically treated group with an independent group requiring treatment (treated-untreated groups design). Only three studies using the pre-post design and four using the independent groups design reported comparable OHIP-14 data and were combined in separate meta-analyses. Meta-analysis was carried out using metan command in Stata. Results:  The standardized mean difference (SMD) in OHIP-14 total score was 1.29 (95% CI: 0.67 to 1.92) for the three studies using the pre-post design. Similarly, the SMD score was 0.84 (95% CI: 0.25 to 1.43) for the four studies using the independent groups design. There was evidence of high heterogeneity and publication bias among the studies included. Conclusions:  This meta-analysis revealed that OHIP-14 scores were significantly lower after receiving treatment for malocclusion and in individuals without malocclusion/orthodontic treatment need compared to those with such condition (independent groups).