***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objective To assess whether Brazilian adolescents who had completed orthodontic treatment  had lower levels of impacts on their oral health-related quality of life . Design A cross-sectional study . Setting The study was conducted in public and private secondary schools in Bauru-SP , Brazil . Participants 1675 r and omly selected adolescents aged between 15 and 16 years . Methods Adolescents were clinical ly examined using the  Index of Orthodontic Treatment Need ( IOTN ) . Two oral health-related quality of life measures , namely the Oral Impacts on Daily Performance ( OIDP ) and the shortened version of the Oral Health Impacts Profile ( OHIP-14 ) were used to assess adolescents ’ oral health-related impacts . Multiple logistic regression was used in the data analysis . Results A response rate of 100 % was obtained . Adolescents who had completed  orthodontic treatment had fewer oral health-related impacts compared to the other two groups . They were 1.85 times ( 95 % CI 1.30 to 2.62 ) less likely to have an oral health impact on their daily life activities than adolescents currently under treatment or 1.43 ( 1.01 to 2.02 ) times than those who never had treatment . Conclusions Adolescents who had completed orthodontic treatment  had a better oral health-related quality of life than those currently under treatment or those who never had treatment The aim of this case-controlled study was to assess the effect of orthodontic treatment on the quality of life of Brazilian adolescents . Two hundred and seventy-nine ' cases ' ( 106 males and 173 females ) and 558 controls ( 246 males and 312 females ) were r and omly selected from 15- to 16-year-old adolescents attending all secondary schools in Bauru , São Paulo , Brazil . A case was defined as having at least one condition-specific impact ( CSI ) attributed to malocclusion during the previous 6 months , based on the Oral Impact on Daily Performances index . Conversely , a control was defined as having no CSI attributed to malocclusion during the same period . Adolescents were also clinical ly examined for  orthodontic treatment  need using the  Index of Orthodontic Treatment Need ( IOTN ) and asked about previous orthodontic treatment . Binary logistic regression was used for statistical analysis . Females and adolescents with a definite normative orthodontic treatment need were more likely to report CSI than males and adolescents with no normative need [ odds ratio ( OR ) = 1.48 , 95 per cent confidence interval ( CI ) = 1.08 - 2.02 and OR = 2.02 , 95 per cent CI = 2.09 - 4.47 , respectively ] , whereas adolescents with a history of orthodontic treatment were less likely to report CSI than their counterparts ( OR = 0.15 , 95 per cent CI = 0.07 - 0.31 ) . Furthermore , there was an interaction between a history of orthodontic treatment and the current level of normative need . Brazilian adolescents with a history of orthodontic treatment  were less likely to have physical , psychological , and social impacts on their daily performances associated with malocclusion than those with no history of orthodontics . Gender was a confounding factor , whereas current level of normative orthodontic treatment need was an effect modifier . Prospect i ve studies are needed to corroborate the present findings A survey was administered to 168 parents and their children at the end of mixed dentition treatment for Class II correction utilizing bionators and headgears  to investigate attitudes of parents and patients toward bionators and headgears and to elicit factors associated with compliance . Directional differences between parent and child responses occurred frequently with agreement ranging from 41 to 100 % , averaging 69 % overall . The results indicate that the orthodontic patient population has medical and dental health as a priority . While parental and child reasons for seeking treatment may be different , it appears that both groups seek care for perceived benefits of health , decreased present and future oral problems , peer influences , and dental self image improvement . Additionally , children who are undergoing treatment perceive that others do not underst and what they are going through , they may be embarrassed , and some may break their appliances to annoy the parent or orthodontist . Pain , decreased ability to speak , and difficulty chewing were reported to decrease appliance wear . Patient underst and ing of the treatment goals was reported to increase compliance . The bionator caused more instances of speech problems and associated non-compliance than the headgear . The headgear caused more instances of pain , but did not cause significantly less associated compliance than the bionator . The results suggest that bolstering the patient-orthodontist relationship , informing the patient about the treatment goals , methods , and their individual role , and offering immediate short term rewards can potentially increase patient compliance INTRODUCTION Our objective was to determine changes in oral health-related quality of life ( OHRQoL ) during fixed orthodontic appliance therapy . METHODS This prospect i ve cohort study included a consecutive sample of 217 children receiving fixed orthodontic appliance therapy .  Each subject completed the 37-item child perception question naire ( CPQ ) at 5 times : before treatment ( T0 ) , and after the placement of the fixed appliance at 1 week ( T1 ) , 1 month ( T2 ) , 3 months ( T3 ) , and 6 months ( T4 ) . RESULTS The response rate was 91 % ( 198 of 217 ) . There were significant changes in overall CPQ scores ( P < .001 ) , oral symptom scores ( P < .001 ) , functional limitation scores ( P < .001 ) , and emotional well-being scores ( P < .001 ) over the study period ( 6 months ) . There were significant differences in certain CPQ domain scores at T1 , T2 , T3 , and T4 compared with T0 ( P < .05 ) and consistently with respect to oral symptoms . Significant changes in certain CPQ domain scores also occurred between T1 and T2 ( P < .05 ) and between T2 and T3 ( P < .05 ) . However , there were no significant changes in social well-being scores ( P > .05 ) . CONCLUSIONS Changes in OHRQoL occur after fixed orthodontic appliance therapy . Compared with pretreatment , a patient 's OHRQoL is frequently worse during treatment ( oral symptoms , functional limitations ) , although it is better in some aspects ( emotional well-being ) . The period of greatest change in OHRQoL occurs during the first month of treatment INTRODUCTION Studies in the dental literature do not yet provide conclusive evidence for the functional and psychosocial benefits of orthodontic treatment . In this cross-sectional study , we aim ed to assess the oral health-related quality of life of young Brazilian adults , aged 18 to 30 years , who had completed orthodontic treatment compared with untreated subjects waiting for treatment .  METHODS The subjects were recruited at a state-funded university clinic . The sample comprised 100 patients in the retention phase of orthodontic treatment for more than 6 months ( treated group ) and 100 persons who were seeking orthodontic treatment and were still on a waiting list ( nontreated group ) . Data were collected by using the oral health impact profile , the index of orthodontic treatment need ( malocclusion severity and esthetic impairment ) , the Brazilian economic classification criteria ( socioeconomic status ) , and the index of decayed , missing , and filled teeth ( oral health status ) . Statistical analyses were performed by using chi-square and Fisher exact tests and negative binomial regression . RESULTS The mean oral health impact profile scores were 3.1 ( SD ± 2.99 ) and 15.1 ( SD ± 8.02 ) in the treated and nontreated groups , respectively . The most frequent impacts in the treated and nontreated groups were " painful aching " and " been self-conscious , " respectively . Comparisons between the groups were controlled for malocclusion severity , clinician-assessed esthetic impairment , age , sex , socioeconomic status , and oral health status . Nontreated young adults had mean oral health impact profile scores 5.3 times higher than did the treated subjects . CONCLUSIONS Young Brazilian adults who received orthodontic treatment  had significantly better oral health-related quality of life scores in the retention phase , after treatment completion , than did nontreated subjects 
    Output:
    
An observed association between quality of life and orthodontic treatment was generally detected irrespective of how they were assessed .
Conclusions Findings of this review suggest that there is an association ( albeit modest ) between orthodontic treatment and quality of life .