***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 
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    ***EXAMPLES*** 
    Input: Objective To evaluate whether patients who had received early class III protraction facemask treatment were less likely to need orthognathic surgery  compared with untreated controls . This paper is a 6-year follow-up of a previous clinical trial . Design Multi-centre 2-arm parallel r and omized controlled trial . Setting Eight United Kingdom hospital orthodontic departments . Participants Seventy three 7- to 9–year-old children . Method Patients were r and omly allocated , stratified for gender , into an  early class III protraction facemask group ( PFG ) ( n = 35 ) and a control/no treatment group ( CG ) ( n = 38 ) . The primary outcome , need for orthognathic surgery  was assessed by panel consensus . Secondary outcomes were changed in skeletal pattern , overjet , Peer Assessment Rating ( PAR ) , self-esteem and the oral aesthetic impact of malocclusion . The data were compared between baseline ( DC1 ) and 6-year follow-up ( DC4 ) . A per- protocol analysis was carried out with n = 32 in the CG and n = 33 in the PFG . Result Thirty six percent of the PFG needed orthognathic surgery , compared with 66 % of the CG ( P = 0.027 ) . The odds of needing surgery was 3.5 times more likely when protraction facemask treatment was not used ( odds ratio = 3.34 95 % CI 1.21–9.24 ) . The PFG exhibited a clockwise rotation and the CG an anti-clockwise rotation in the maxilla ( regression coefficient 8.24 ( SE 0.75 ) ; 95 % CI 6.73–9.75 ; P < 0.001 ) and the m and ible ( regression coefficient 6.72 ( SE 0.73 ) ; 95 % CI 5.27–8.18 ; P < 0.001 ) . Sixty eight per cent of the PFG maintained a positive overjet at 6-year follow-up . There were no statistically significant differences between the PFG and CG for skeletal/occlusal improvement , self-esteem or oral aesthetic impact . Conclusions Early class III protraction facemask treatment reduces the need for orthognathic surgery . However , this effect can not be explained by the maintenance of skeletal cephalometric change 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 In this cephalometric investigation , we analyzed the treatment and posttreatment effects of an orthopedic protocol for Class III malocclusion consisting of a facial mask combined with a removable bite-block appliance . METHODS The treated sample consisted of 22 Class III patients treated with the facial mask and bite-block protocol before the pubertal growth spurt ( mean age , 8.9 + /- 1.5 years ) . Treated subjects were evaluated after facial mask and bite-block therapy and at a posttreatment observation in absence of retention . The treated group was compared with a matched control group of 12 untreated Class III subjects . All treated and control subjects were postpubertal at the final observation . Significant differences between the treated and control groups were assessed with the Mann-Whitney U test ( P < 0.05 ) . RESULTS Both angular and linear sagittal measurements of the maxilla showed significant improvements during active treatment . Significant improvements of SNA angle , ANB angle , overjet , and molar relationship remained stable during the posttreatment period . No significant effect was found in the m and ibular skeletal measures . No significant protraction of the maxillary incisors or retraction of the m and ibular incisors was observed . CONCLUSIONS A bite-block appliance in the m and ibular arch with a facial mask enabled effective control of m and ibular rotation with progressive closure of the gonial angle . This added to the favorable maxillary outcomes of the treatment protocol INTRODUCTION The purpose of this controlled r and omized clinical trial was to quantify the effects of maxillary protraction with or without palatal expansion . METHODS Forty-six children aged 5 to 10 years were r and omly assigned to 1 of 3 groups : ( 1 ) facemask with palatal expansion , ( 2 ) facemask without palatal expansion , and ( 3 ) observation for 12 months . Cephalometric analysis with traditional cephalometric measurements , an x-y coordinate system , and an occlusal-plane analysis were used . RESULTS Student t tests showed no significant differences ( P < .05 ) between expansion and nonexpansion groups in any measured variable . Comparisons of treated and control subjects showed significant ( P < .01 ) treatment effects beyond normal Class III growth . Analysis of x-y coordinate variables showed the following : 2 mm additional forward displacement of the maxillary complex with counterclockwise rotation , m and ibular clockwise rotation , posterior movement of B-point by an average of 1.5 mm , and forward movement of the maxillary dentition of nearly 1 mm . Analysis of traditional cephalometric measures showed improvements in ANB angle of nearly 4 degrees and Wits appraisal of nearly 4 mm . The occlusal plane analysis showed an apical base change of 4 mm , 1.5 mm forward displacement of the maxillary complex , m and ibular clockwise rotation of 2.5 mm , and forward maxillary molar movement of 1.9 mm . CONCLUSIONS The results of this continuing 5-year clinical trial indicate that early facemask therapy , with or without palatal expansion , is effective to correct skeletal Class III malocclusions The aim of this study was to select a model of cephalometric variables to predict the results of early treatment of Class III malocclusion with rapid maxillary expansion and facemask therapy followed by comprehensive treatment with fixed appliances . Lateral cephalograms of 42 patients ( 20 boys , 22 girls ) with Class III malocclusion were analyzed at the start of treatment ( mean age 8 years 6 months + /- 2 years , at stage I in cervical vertebral maturation ) . All patients were reevaluated after a mean period of 6 years 6 months ( at stage IV or V in cervical vertebral maturation ) that included active treatment plus retention . At this time , the sample was divided into 2 groups according to occlusal criteria : a successful group ( 30 patients ) and an unsuccessful group ( 12 patients ) . Discriminant analysis was applied to select pretreatment predictive variables of long-term treatment outcome . Stepwise variable selection of the cephalometric measurements at the first observation identified 3 predictive variables . Orthopedic treatment of Class III malocclusion might be unfavorable over the long term when a patient 's pretreatment cephalometric records exhibit a long m and ibular ramus ( ie , increased posterior facial height ) , an acute cranial base angle , and a steep m and ibular plane angle . On the basis of the equation generated by the multivariate statistical method , the outcome of interceptive orthopedic treatment  for each new patient with Class III malocclusion can be predicted with a probability error of 16.7 % The material of this investigation consisted of 40 functional Class III malocclusion subjects . Each treatment and control group consisted of 20 Class III cases ( 10 boys and 10 girls ) . The mean age of the subjects in the function regulator , FR-3 , group was 9.5 years at the beginning of the treatment , and in the control group 9.3 years at the beginning of the observation period . The mean treatment period of the FR-3 group was 1.9 years and the mean observation period of the control group is 1.8 years . In this study , as a result of FR-3 appliance therapy in the functional Class III malocclusion group , the negative overjet that was present at the beginning of the treatment has been converted into a positive overjet by an average increase of 3.8 mm at the end of the treatment . The sum of downward and backward rotation of the m and ible , the decrease in the SNB angle with a subsequent increase of the ANB angle , and the retrusion of the lower incisors were effective in the increase of the overjet . The increase in the SNA angle and the protrusion of the upper incisors were found to be insignificant . The overbite decreased due largely to the downward and backward rotation of the m and ible INTRODUCTION Bone-anchored maxillary protraction has been shown to be an effective treatment modality for the correction of Class III malocclusions . The purpose of this study was to evaluate 3-dimensional changes in the maxilla , the surrounding hard and soft tissues , and the circummaxillary sutures after bone-anchored maxillary protraction treatment . METHODS Twenty-five consecutive skeletal Class III patients between the ages of 9 and 13 years ( mean , 11.10 ± 1.1 years ) were treated with Class III intermaxillary elastics and bilateral miniplates ( 2 in the infrazygomatic crests of the maxilla and 2 in the anterior m and ible ) . Cone-beam computed tomographs were taken before initial loading and 1 year out . Three-dimensional models were generated from the tomographs , registered on the anterior cranial base , superimposed , and analyzed by using color maps . RESULTS The maxilla showed a mean forward displacement of 3.7 mm , and the zygomas and the maxillary incisors came forward 3.7 and 4.3 mm , respectively . CONCLUSIONS This treatment approach produced significant orthopedic changes in the maxilla and the zygomas in growing Class III patients A prospect i ve clinical trial was conducted to determine the cephalometric and occlusal changes following maxillary expansion and protraction .  Twenty Southern Chinese patients ( eight males and 12 females with a mean age of 8.4 + /- 1.8 years ) with skeletal Class III malocclusions were treated consecutively with maxillary expansion and a protraction facemask . Growth adaptation of these patients was followed for 2 years after removal of the appliances and compared with a control group of subjects with no treatment . Lateral  cephalometric radiographs  were used to quantify the skeletal and dental changes before treatment ( T1 ) , immediately after treatment ( T2 ) and 2 years after removal of appliances ( T3 ) . With 8 months of treatment ( T2-T1 ) , overjet was overcorrected from a -2.0 to 3.5 mm . The maxilla moved forwards by an average of 2.1 mm and the molar relationship was improved to a Class I dental arch relationship . The palatal and occlusal planes were tilted upward 1.0 and 2.0 degrees , respectively . Two years following removal of the appliances ( T3-T2 ) , a positive overjet was maintained in 18 out of 20 patients . The maxilla continued to move forwards in the treated subjects similar to the controls . The m and ible outgrew the maxilia . In most instances , dental compensation with proclination of the maxillary incisors was observed . The palatal plane returned to pre-treatment value . The occlusal plane continued to tilt upward due to eruption of the molars and proclination of the incisors . Analysis of dental casts showed a significant increase in maxillary intercanine ( 2.2 mm ) and intermolar widths ( 2.3 mm ) 
    Output:
    
Conclusions Maxillary protraction can be a short-term effective therapy and might improve sagittal skeletal and dental relationships in the medium term .
But some skeletal and dental variables showed significant relapse during the follow-up period .