***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: INTRODUCTION The aim of this study was to evaluate the effectiveness of early orthodontic treatment with the Twin-block appliance for the treatment of Class II Division 1 malocclusion . This was a multi-center , r and omized , controlled trial with subjects from 14 orthodontic clinics in the United Kingdom . METHODS The study included 174 children aged 8 to 10 years with Class II Division 1 malocclusion ; they were r and omly allocated to receive treatment with a Twin-block appliance or to an initially untreated control group . The subjects were then followed until all orthodontic treatment was completed . Final skeletal pattern , number of attendances , duration of orthodontic treatment , extraction rate , cost of treatment , and the child 's self-concept were considered . RESULTS At the end of the 10-year study , 141 patients either completed treatment or accepted their occlusion . Data analysis showed that there was no differences between those who received early Twin-block treatment and those who had 1 course of treatment in adolescence with respect to skeletal pattern , extraction rate , and self-esteem . Those who had early treatment had more attendances , received treatment for longer times , and incurred more costs than the adolescent treatment group . They also had significantly poorer final dental occlusion . CONCLUSIONS Twin-block treatment when a child is 8 to 9 years old has no advantages over treatment started at an average age of 12.4 years . However , the cost of early treatment to the patient in terms of attendances and length of appliance wear is increased INTRODUCTION Our aim in this prospect i ve r and omized clinical study was to assess the prevalence rate of eruption of palatally displaced canines , diagnosed at an early developmental stage with posteroanterior radiographs and consequently treated by rapid maxillary expansion . METHODS A sample of 60 subjects in the early mixed dentition with palatally displaced canines diagnosed on posteroanterior radiographs was enrolled in the trial . Their age range at the first observation ( T1 ) was 7.6 to 9.6 years , with a prepubertal stage of skeletal maturity ( CS1 or CS2 ) . The 60 subjects were r and omly allocated to the treatment group ( TG , 35 subjects ) or the no-treatment group ( NTG , 25 subjects ) . The TG was treated with a b and ed rapid maxillary exp and er ; after expansion , all patients were retained with the exp and er in place for 6 months . Thereafter , the exp and er was removed , and the patients wore a retention plate at night for a year . The NTG received no treatment . All subjects were reevaluated in the early permanent dentition ( T2 ) ( postpubertal CS4 ) . The number of dropouts was recorded . The main outcome recorded at T2 was successful or unsuccessful eruption of the maxillary permanent canines . The starting forms at T1 for measurements on posteroanterior and panoramic films were compared in the 2 groups with the Mann-Whitney U test ( P < 0.05 ) . The prevalence rates of successful and unsuccessful treatments in the TG were compared with those in NTG with chi-square tests ( P < 0.05 ) . From T1 to T2 , there were 3 dropouts in each group . RESULTS The final sample comprised 32 subjects in the TG and 22 subjects in the NTG . No statistically significant differences were found for any variable at T1 . The prevalence rates of successful eruption of the maxillary canines were 65.7 % ( 21 subjects ) in the TG and 13.6 % ( 3 subjects ) in the NTG . The comparison was statistically significant ( chi-square = 12.4 ; P < 0.001 ) . Subjects with palatally displaced canines in the early mixed dentition do not have transverse deficiency of the maxillary arch . CONCLUSIONS The use of a rapid maxillary exp and er as an early interceptive approach is effective for increasing the rate of eruption of palatally displaced canines INTRODUCTION There are disparities in access to orthodontic treatment for children from low-income families . Systematic programs of limited-care interceptive and preventive orthodontics have been proposed as a solution . The purpose of this r and omized clinical trial was to compare dental outcomes and funding eligibility from a group of Medicaid patients r and omized to receive interceptive orthodontics ( IO ) in the mixed dentition or observation ( OBS ) . METHODS One hundred seventy Medicaid-eligible children were r and omized to receive IO or OBS and followed for 2 years , when complete data were available on 72 and 74 children , respectively . The 2-year changes in the peer assessment rating ( PAR ) were compared using the Student t test . The proportions of children no longer eligible for Medicaid funding as defined by h and icapping labiolingual deviation ( HLD ) scores less than 25 at the 2-year follow-up were compared with the chi-square test . RESULTS The IO patients had significantly greater decreases in the PAR scores--50%-compared with the OBS subjects , -6 % ( P < 0.001 ) . Negative and positive overjet and maxillary alignment were the components most affected by IO ; they decreased by 11.0 , 7.2 , and 3.7 PAR points , respectively ( P < 0.001 ) . Overbite showed little change . At the 2-year follow-up , 80 % of the IO patients ' malocclusions that qualified initially were no longer deemed medically necessary by the HLD index , compared with 6 % in the OBS group ( P < 0.001 ) . CONCLUSIONS IO significantly reduces the severity of malocclusions and moves most from the " medically necessary " category to elective but does not produce finished results for most patients . Overjet and alignment were most readily corrected by interceptive treatment . Deep overbites were the least susceptible to IO correction In a 2-phased , parallel , r and omized trial of early ( preadolescent ) versus later ( adolescent ) treatment for children with severe ( > 7 mm overjet ) Class II malocclusions who initially were developmentally at least a year before their peak pubertal growth , favorable growth changes were observed in about 75 % of those receiving early treatment with either a headgear or a functional appliance .  After a second phase of fixed appliance treatment for both the previously treated children and the untreated controls , however , early treatment had little effect on the subsequent treatment outcomes measured as skeletal change , alignment , and occlusion of the teeth , or length and complexity of treatment . The differences created between the treated children and untreated control group by phase 1 treatment before adolescence disappeared when both groups received comprehensive fixed appliance treatment during adolescence . This suggests that 2-phase treatment started before adolescence in the mixed dentition might be no more clinical ly effective than 1-phase treatment started during adolescence in the early permanent dentition . Early treatment also appears to be less efficient , in that it produced no reduction in the average time a child is in fixed appliances during a second stage of treatment , and it did not decrease the proportion of complex treatments involving extraction s or orthognathic surgery INTRODUCTION Many research ers have examined the prevalence of dental injuries in children and adolescents . The purpose of this study was to examine the prevalence and incidence of incisor trauma in subjects who participated in a r and omized clinical trial design ed to investigate early growth modifications in the treatment of Class II malocclusion . METHODS The subjects were r and omized to 3 treatment groups during the initial phase of the study : ( 1 ) headgear or biteplane , ( 2 ) bionator , and ( 3 ) observation ( no treatment ) . All 3 groups underwent phase 2 treatment with fixed appliances . Incisor injury was scored at every data collection point with the Ellis index by a blinded examiner using dental casts , intraoral photos , and panoramic and periapical x-rays . RESULTS Twenty-five percent of the subjects had  incisor trauma at the baseline examination , and 28 % experienced new or worsening maxillary incisor injury during the study . No significant differences were found with regard to sex and prevalence of injury at baseline . No differences in incidence of trauma were found between the 3 treatment groups throughout the study ( P = 0.19 ) ; however , boys were more likely to experience maxillary incisor injury ( odds ratio estimate , 2.37 ; 95 % CI , 1.33 , 4.21 ) , and those with an injury at baseline were more likely to experience an additional injury ( odds ratio estimate , 1.81 ; 95 % CI , 1.03 , 3.17 ) . CONCLUSIONS Early orthodontic treatment did not affect the incidence of incisor injury . The majority of the injuries before and during treatment were minor ; therefore , the cost-benefit ratio of orthodontic treatment primarily to prevent incisor trauma is unfavorable OBJECTIVE To investigate the effectiveness of early class III protraction facemask treatment in children under 10 years of age at 3-year follow-up . DESIGN Multicentre r and omized controlled trial . SUBJECTS AND METHODS Seventy-three patients were r and omly allocated , stratified for gender , into early class III protraction facemask group ( PFG ) ( n = 35 ) and a control/no treatment group ( CG ) ( n = 38 ) . OUTCOMES Dentofacial changes were assessed from lateral cephalograms and occlusal changes using the peer assessment rating ( PAR ) . Self-esteem was assessed using the Piers-Harris children 's self-concept scale , and the psychosocial impact of malocclusion with oral aesthetic subjective impact score ( OASIS ) question naire . Temporom and ibular joint ( TMJ ) signs and symptoms were also recorded . The time points for data collection were at registration ( DC1 ) , 15 months later ( DC2 ) and 3 years post- registration ( DC3 ) . RESULTS The following mean skeletal and occlusal changes occurred from the class III starting point to DC3 ( 3-year follow-up ) : SNA , PFG moved forwards + 2·3 ° ( CG forward + 1·6 ° ; P = 0·14 ) ; SNB , PFG moved forwards + 0·8 ° ( CG forward + 1·5 ° , P = 0·26 ) ; ANB , PFG class III base improved + 1·5 ° ( CG stayed about the same at + 0·1 ° ; P = 0·001 ) . This contributed to an overall difference in ANB between PFG and CG of + 1·4 ° in favour of early protraction facemask treatment . The overjet was still improved by + 3·6 mm in the PFG and changed a small amount + 1·1 mm in the CG ( P = 0·001 ) . A 21 % improvement in PAR was shown in the PFG and the CG worsened by 8·4 % ( P = 0·02 ) . There was no increase in self-esteem ( Piers-Harris score ) for PFG compared with the CG ( P = 0·56 ) and no statistically significant difference in the impact of malocclusion ( OASIS ) between groups in terms of the changes from DC1 to DC3 ( P = 0·18 ) . TMJ signs and symptoms were very low at DC1 and DC3 . CONCLUSIONS The favourable effect of  early class III protraction facemask treatment undertaken in patients under 10 years of age , is maintained at 3-year follow-up in terms of ANB , overjet and % PAR improvement . The direct protraction treatment effect at SNA is still favourable although not statistically significantly better than the CG . Seventy per cent of patients in PFG had maintained a positive overjet which we have defined as ongoing treatment success . Early protraction facemask treatment does not seem to influence self-esteem or reduce the patient 's personal impact of their malocclusion at 3-year follow-up INTRODUCTION The objective of this 3-arm parallel r and omized clinical trial was to compare the effectiveness of temporary anchorage devices ( TADs ) , Nance button palatal arches , and headgear for anchorage supplementation in the treatment of patients with malocclusions that required maximum anchorage . This trial was conducted between August 2008 and February 2013 in 2 orthodontic departments in the United Kingdom . METHODS The study included 78 patients ( ages , 12 - 18 years ; mean age , 14.2 years ) who needed maximum anchorage . Eligibility criteria included no active caries , exemplary oral hygiene , and maximum anchorage required . OUTCOME The primary outcome was mesial molar movement during the period in which anchorage supplementation was required . The secondary outcomes were duration of anchorage reinforcement , number of treatment visits , number of casual and failed appointments , total treatment time , dento-occlusal change , and patients ' perceptions of the method of anchorage supplementation . R AND OMIZATION Treatment allocation was implemented by contacting via the Internet the r and omization center at the University of Nottingham , Clinical Trials Unit . The r and omization was based on a computer-generated pseudo-r and om code with r and om permuted blocks of r and omly varying size . BLINDING A research assistant who was blinded to the group allocation recorded all data . INTERVENTION The patients were r and omly allocated to receive anchorage supplementation with TADs , a Nance button on a palatal arch , or headgear . They were all treated with maxillary and m and ibular preadjusted edgewise fixed appliances with 0.022-in slot prescription brackets . They were followed until orthodontic treatment was complete . RESULTS Seventy-eight patients were r and omized in a 1:1:1 ratio among the 3 groups . The baseline characteristics were similar in the groups , and they were treated for an average of 27.4 months ( SD , 7.1 months ) ; 71 completed orthodontic treatment . The data were analyzed on a per- protocol basis and showed no differences in the effectiveness of anchorage supplementation between 
    Output:
    
The results suggest a lack of evidence to prove that early treatment carries additional benefit over and above that achieved with treatment commencing later ; however , this does not necessarily imply that early treatment is ineffective .