Longitudinal prospective evaluation of oral health-related quality of life in young patients undergoing fixed orthodontic appliance treatment as part of a randomised trial

Abstract Background The objectives of this study were to investigate relationships between change in the aesthetic appearance before and after orthodontic treatment and patient-reported change in oral health-related quality of life (OHRQoL), and to assess the responsiveness of two OHRQoL measures to any changes from orthodontic treatment. Methods Two hundred and ten participants in a multicentre (two teaching hospitals and four specialist orthodontic practices), single blinded, randomised clinical trial with 2 parallel groups, were administered one of two age-specific questionnaires, either the Child Perceptions Questionnaire (CPQ11-14-ISF-16) or the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ), before and after orthodontic treatment. Clinical photographs were assessed by two groups of laypeople and orthodontists using the Index of Orthodontic Treatment Need Aesthetic Component (IOTN-AC). Results Two hundred and ten participants were randomised, and 197 completed the trial. Before and after OHRQoL data were successfully obtained from 110 participants. There was a mean reduction in the total CPQ11-14-ISF-16 scores of 3.9 (SD = 8.0), and a mean reduction of 34.2 (SD = 18.5) in the total PIDAQ score. CPQ11-14-ISF-16 demonstrated poor longitudinal construct validity (p = 0.155). Correlations between the change in total CPQ11-14-ISF-16 scores and change in IOTN-AC assessments were small for both orthodontists (r=-0.084; p = 0.516) and laypeople (r=-0.140; p = 0.225). There were higher associations between the improvement in the Social well-being (SWB) subdomain and improvement in IOTN-AC. Correlations between the changes in total PIDAQ scores and the IOTN-AC assessments, were higher in comparison to the correlations with CPQ11-14-ISF-16 (orthodontists; r = 0.223, laypeople; r = 0.025). There were no adverse effects. Conclusion CPQ11-14-ISF-16 and IOTN-AC measure different attributes. This demonstrated the role of SWB on children OHRQoL. Condition-specific measures (PIDAQ) are more responsive to change in self-reported OHRQoL than generic measures (CPQ11-14-ISF-16) after treatment. Trial Registration: The trial was registered at ClinicalTrials.gov NCT01925924.