title: Does orthodontic treatment before the age of 18 years improve oral health-related quality of life? A systematic review and meta-analysis.
abstract: BACKGROUND
  Orthodontics aims to improve oral health-related quality of life (OHRQoL). In this systematic review, we examined the evidence for changes in OHRQoL after orthodontic treatment for patients treated before they were 18 years old.
  
  
  METHODS
  The participants were patients aged less than 18 years. The interventions were nonorthognathic and cleft orthodontic treatment. The comparisons were before and after orthodontic treatment, or nonorthodontic control. The outcomes were validated measures of OHRQoL. The study designs were randomized controlled trials, controlled clinical trials, prospective cohort studies, and cross-sectional or case-control studies. Multiple electronic databases were searched, with no language restrictions; authors were contacted, and reference lists screened. The Newcastle-Ottawa scale was used for quality assessments. Screening, data extraction, and quality assessments were performed by 2 investigators independently.
  
  
  RESULTS
  We found 1590 articles and included 13 studies (9 cohort, 3 cross sectional, and 1 case control), with 6 in the meta-analyses. All were judged of low or moderate quality. A moderate improvement in OHRQoL was observed before and after orthodontic treatment (n = 243 participants; standardized mean difference, -0.75; 95% CI, -1.15 to -0.36) particularly in the dimensions of emotional well-being (n = 213 participants; standardized mean difference, -0.61; 95% CI, -0.80 to -0.41) and social well-being (n = 213 participants; standardized mean difference, -0.62; 95% CI, -0.82 to -0.43).
  
  
  CONCLUSIONS
  Orthodontic treatment during childhood or adolescence leads to moderate improvements in the emotional and social well-being dimensions of OHRQoL, although the evidence is of low and moderate quality. More high quality, longitudinal, prospective studies are needed.
authors.affiliation: Academic Unit of Oral Health and Development, School of Clinical Dentistry, University of Sheffield, Sheffield, United Kingdom.
authors.forename: Hanieh
authors.initials: H
authors.lastname: Javidi
authors.affiliation: Academic Unit of Oral Health and Development, School of Clinical Dentistry, University of Sheffield, Sheffield, United Kingdom.
authors.forename: Mario
authors.initials: M
authors.lastname: Vettore
authors.affiliation: Academic Unit of Oral Health and Development, School of Clinical Dentistry, University of Sheffield, Sheffield, United Kingdom. Electronic address: p.benson@sheffield.ac.uk.
authors.forename: Philip E
authors.initials: PE
authors.lastname: Benson
mesh_terms: D000293:Adolescent; D000367:Age Factors; D006801:Humans; D009909:Oral Health; D009971:Orthodontics, Corrective / Q000523:psychology; D011788:Quality of Life