title: Malocclusion, orthodontic treatment, and the Oral Health Impact Profile (OHIP-14): Systematic review and meta-analysis.
abstract: 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.
  
  
  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).
authors.affiliation: a  PhD student, Biostatistics and Research Methods Centre, Dental Institute, King's College London, London, UK.
authors.forename: Manoharan
authors.initials: M
authors.lastname: Andiappan
authors.forename: Wei
authors.initials: W
authors.lastname: Gao
authors.forename: Eduardo
authors.initials: E
authors.lastname: Bernabé
authors.forename: Ngianga-Bakwin
authors.initials: NB
authors.lastname: Kandala
authors.forename: Ana Nora
authors.initials: AN
authors.lastname: Donaldson
mesh_terms: D065187:Controlled Before-After Studies; D006801:Humans; D008310:Malocclusion / Q000523:psychology* / Q000628:therapy; D064887:Observational Studies as Topic; D009971:Orthodontics, Corrective / Q000523:psychology*; D011788:Quality of Life
keywords: Malocclusion; Oral health related quality of life; Orthodontic treatment; Review