Sensitively and responsiveness of the CPQ to orthodontic treatment

OBJECTIVES: To assess the sensitivity and responsiveness of the Child Perception Questionnaire (CPQ) to orthodontic care. METHODS: Adolescents (124) undergoing fixed orthodontic appliance therapy (FOAT) completed the CPQ pre FOAT and 6-months after FOAT. Sensitivity was evaluated in terms of observed changes in CPQ scores. Responsiveness was assessed in terms of the gradient of observe changes in CPQ scores and the magnitude of the changes in CPQ scores (effect sizes). Pre and Post treatment study casts were assessed to determine changes in occlusion based on the Index of Complexity and Orthodontic Need (ICON) criteria. Subjects rated their perceived improvement in oral health post treatment on a global scale with reference to their pre treatment status. RESULTS: In terms of sensitivity, observed changes were apparent in overall CPQ scores (P<0.001) and across all sub-domain scores, notably emotional and social well being (P<0.001). There was an observed gradient in observed change in CPQ scores and in the magnitude of such changes (effect sizes) in relation to global rating of improvements in oral health and with respect to ICON improvement ratings. CONCLUSION: The Child Perception Questionnaire is sensitive and responsive to the effects of fixed orthodontic appliance therapy. These findings have implications for the use of oral health related quality of life measures in assessing outcomes from orthodontic care.