title: A closer look at General Dental Service orthodontics in England and Wales. I: Factors influencing effectiveness.
abstract: OBJECTIVE
  To evaluate factors influencing effectiveness in General Dental Service (GDS) orthodontics.
  
  
  METHODS
  Retrospective analysis of systematic 2% sample of GDS (England and Wales) cases.
  
  
  METHODS
  Records of cases were collected during 1991. Assessment involved occlusal indices and data from National Health Service forms for 1,411 cases. Multivariate analyses were used with Peer Assessment Rating Index (PAR) score at Finish as the outcome indicator.
  
  
  RESULTS
  Dual arch fixed appliances: achieved lower Finish PAR scores than other appliances; only 1.5% of the variance was explained, by treatment time and Dental Health Component of the Index of Orthodontic Treatment Need (DHC). Finish PAR was unaffected by Starting PAR. All other appliances: the model explained 25% of the variance for Finish PAR, which varied with Starting PAR and DHC scores. Social class had effects of little clinical significance, but the data suggested availability of orthodontic treatment was poorer in 'manual class' areas. Orthodontic qualifications, number of arches treated and mixed dentition starts had no significant effects when submitted to multivariate analysis.
  
  
  CONCLUSIONS
  The importance of appliance selection is reinforced: dual arch fixed appliances are generally more consistent. Lower social class areas may be poorly provided with orthodontic services.
authors.affiliation: Oral Health and Development Group, University Dental Hospital of Manchester.
authors.forename: E A
authors.initials: EA
authors.lastname: Turbill
authors.forename: S
authors.initials: S
authors.lastname: Richmond
authors.forename: J L
authors.initials: JL
authors.lastname: Wright
mesh_terms: D000367:Age Factors; D002648:Child; D003724:Dental Arch; D003818:Dentition, Mixed; D004739:England; D005792:General Practice, Dental / Q000193:education; D006297:Health Services Accessibility; D006301:Health Services Needs and Demand; D006801:Humans; D008310:Malocclusion / Q000145:classification / Q000628:therapy*; D015999:Multivariate Analysis; D009967:Orthodontic Appliances; D009970:Orthodontics / Q000193:education; D009971:Orthodontics, Corrective / Q000706:statistics & numerical data; D010347:Patient Care Planning; D018024:Peer Review, Health Care; D012189:Retrospective Studies; D012923:Social Class; D013222:State Medicine; D013997:Time Factors; D016896:Treatment Outcome; D014852:Wales