Evaluating oral health-related quality of life measure for children and preadolescents with temporomandibular disorder

Five hundred and forty-seven students aged 8-14 years were recruited from public schools in Piracicaba, Brazil. Self-perceptions of QoL were measured using the Brazilian Portuguese versions of Child Perceptions Questionnaires (CPQ)8-10 (n = 247) and CPQ11-14 (n = 300). A single examiner, trained and calibrated for diagnosis according to the Axis I of the Research Diagnostic Criteria for TMD (RDC/TMD), examined the participants. A self-report questionnaire assessed subjective symptoms of TMD. Intraexaminer reliability was assessed for the RDC/TMD clinical examinations using Cohen's Kappa (κ) and intraclass correlation coefficient (ICC). Criterion validity was calculated using the Spearman's correlation, construct validity using the Spearman's correlation and the Mann-Whitney test, and the magnitude of the difference between groups using effect size (ES). Reliability was determined using Cronbach's alpha, alpha if the item was deleted and corrected item-total correlation.Intraexaminer reliability values ranged from regular (κ = 0.30) to excellent (κ = 0.96) for the categorical variables and from moderate (ICC = 0.49) to substantial (ICC = 0.74) for the continuous variables. Criterion validity was supported by significant associations between both CPQ scores and pain-related questions for the TMD groups. Mean CPQ8-10 scores were slightly higher for TMD children than control children (ES = 0.43). Preadolescents with TMD had moderately higher scores than the control ones (ES = 0.62; p < 0.0001). Significant correlation between the CPQ scores and global oral health, as well as overall well-being ratings (p < 0.001) occurred, supporting the construct validity. The Cronbach's alphas were 0.93 for CPQ8-10 and 0.94 for CPQ11-14. For the overall CPQ8-10 and CPQ11-14 scales, the corrected item-total correlation coefficients ranged from 0.39-0.76 and from 0.28-0.73, respectively. The alpha coefficients did not increase when any of the items were deleted in either CPQ samples.The