title: Evaluating oral health-related quality of life measure for children and preadolescents with temporomandibular disorder.
abstract: BACKGROUND
  Oral health-related quality of life (OHRQoL) in children and adolescents with signs and symptoms of temporomandibular disorder (TMD) has not yet been measured. This study aimed to evaluate the validity and reliability of OHRQoL measure for use in children and preadolescents with signs and symptoms of TMD.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  The questionnaires are valid and reliable for use in children and preadolescents with signs and symptoms of temporomandibular disorder.
authors.affiliation: Department of Pediatric Dentistry, Piracicaba Dental School, State University of Campinas, Piracicaba/SP, Brazil.
authors.forename: Taís S
authors.initials: TS
authors.lastname: Barbosa
authors.forename: Marina S
authors.initials: MS
authors.lastname: Leme
authors.forename: Paula M
authors.initials: PM
authors.lastname: Castelo
authors.forename: Maria Beatriz D
authors.initials: MB
authors.lastname: Gavião
mesh_terms: D000293:Adolescent; D001938:Brazil; D002648:Child; D003430:Cross-Sectional Studies; D005157:Facial Pain / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D009909:Oral Health; D011594:Psychometrics / Q000706:statistics & numerical data; D011788:Quality of Life; D015203:Reproducibility of Results; D012649:Self Concept; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires / Q000592:standards; D013705:Temporomandibular Joint Disorders / Q000503:physiopathology / Q000523:psychology*