Objectives: To determine the association between the impact of oral health on quality of life (OHQoL) among children and their need for orthodontic treatment.
Methods: Children (217) were screened for orthodontic treatment need using a number of professionally derived indices: Index of Orthodontic Treatment Need (IOTN)--Aesthetic Component (AC) and Dental Health Component (DHC); Index of Complexity, Outcome and Need (ICON) and the Dental Aesthetic Index (DAI). In addition, all children self-completed the 37-item Child Perception Questionnaire (CPQ), a measure of OHQoL, to assess Oral Symptoms (OS) experienced, Functional Limitation (FL), Emotional Well Being (EWB) and Social Well Being (SWB).
Results: Different prevalence of orthodontic treatment need was observed depending on occlusal indices used (ranged from 31.6% to 85.9%). However, there were significant correlations between the different occlusal indices (p < 0.01). Significant differences in overall CPQ scores existed between those with and without an orthodontic treatment need irrespective of occlusal indices used to categorize treatment need (p < 0.05); Effect sizes ranged from 0.24 to 0.51. However no single index's categorization of treatment need could identify variations in all of CPQ domain scores (OS, FL, EWB and SWB).
Conclusion: Different occlusal indices (AC, DHC, ICON and DAI) prescribe a different prevalence of orthodontic treatment need. Those categorized as having an orthodontic treatment need by AC, DHC, ICON and DAI criteria had poorer overall OHQoL compared to those ascribed as not having a treatment need. None of the occlusal indices could comprehensively differentiate poorer OHQoL across all its domains.