***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 investigate the duration of m and ibular-crowding alleviation with self-ligating brackets compared with conventional appliances and the accompanying dental effects . METHODS Fifty-four subjects were selected from a pool of patients satisfying the following inclusion criteria : non extraction treatment in the m and ibular or maxillary arches ; eruption of all m and ibular teeth ; no spaces in the m and ibular arch ; irregularity index greater than 2 in the m and ibular arch ; and no therapeutic intervention planned with any extraoral or intraoral appliance . The patients were r and omly assigned to 2 groups : 1 group received treatment with a self-ligating bracket ( Damon 2 , Ormco , Glendora , Calif ) and the other with a conventional edgewise appliance ( Microarch , GAC , Central Islip , NY ) , both with 0.022-in slots . The irregularity index of the m and ibular arch was normalized between the groups , and the time to alignment was estimated in days . Treatment duration was assessed by data modeling with the Cox proportional hazard regression . Lateral cephalometric radiographs were used to assess the alteration of m and ibular incisor position before and after alignment . Measurements of intercanine and intermolar widths were also made on dental casts to determine changes associated with correction . RESULTS AND CONCLUSIONS Overall , no difference in the time required to correct m and ibular crowding with Damon 2 and conventional brackets was observed . For moderate crowding ( irregularity index < 5 ) , however , the self-ligating group had 2.7 times faster correction . This difference was marginally insignificant for subjects with irregularity index scores greater than 5 . Greater crowding prolonged treatment by an additional 20 % for each irregularity index unit . Increases in intercanine and intermolar widths associated with crowding correction regardless of bracket group were noted . The self-ligating group showed a statistically greater intermolar width increase than the conventional group . Also , an alignment-induced increase in the proclination of the m and ibular incisors was observed for both bracket groups , but no difference was found between Damon 2 and conventional brackets for this parameter OBJECTIVE To measure space closure during the retraction of upper permanent canines with self-ligating and conventional brackets . MATERIAL S AND METHODS Fifteen patients who required maxillary canine retraction into first premolar extraction sites as part of their orthodontic treatment completed this study . In a r and om split-mouth design , the retraction of upper canines was performed using an elastomeric chain with 150 g of force . The evaluations were performed in dental casts ( T0 , initial ; T1 , 4 weeks ; T2 , 8 weeks ; T3 , 12 weeks ) . The amount of movement and the rotation of the canines as well as anchorage loss of the upper first molars were evaluated . RESULTS There was no difference between self-ligating and conventional brackets regarding the distal movement of upper canines and mesial movement of first molars ( P > .05 ) . Rotation of the upper canines was minimized with self-ligating brackets ( P < .05 ) . CONCLUSION Distal movement of the upper canines and anchorage loss of the first molars were similar with both conventional and self-ligating brackets .  Rotation of the upper canines during sliding mechanics was minimized with self-ligating brackets The aims of this investigation were to determine the errors involved in cephalometric l and mark identification and to link these to the interpretation of treatment results . Fifty cephalograms were r and omly selected from patient files and the following were determined . ( i ) Accuracy of the digitizer -- single tracing digitized on five occasions on each of 10 different positions on the digitizer by one observer . ( ii ) Intra- and inter-observer digitizing error--35 l and marks on the same tracing ( on a fixed position ) digitized on five occasions by each of four judges . ( iii ) Intra- and inter-observer  tracing error -- five separate tracings of 10 different cephalograms by four judges . There were no significant differences in the variances of the co-ordinates for each l and mark between the different positions on the digitizer ( mean variance x-axis 0.07 mm and y-axis 0.08 mm ) . ( ii ) One-way ANOVA showed no significant intra- or inter-observer differences in digitation . ( iii ) Levene 's test for homogeneity of variance showed significant differences in the co-ordinates of different l and marks and between the same l and marks on different cephalograms . Two-way ANOVA showed significant differences between observers for the same l and mark that were greater than the intra-observer differences . The results indicate that tracing accuracy is a limiting factor in cephalometry . The variance of each l and mark is dependent on the quality of the cephalogram . Inter-observer differences were greater than intra-observer effects and these were r and om , rather than systematic errors . Minimal error estimation calculations enable discrimination between treatment results and measurement errors OBJECTIVE To compare the rates of retraction down an archwire of maxillary canine teeth when bracketed with a self-ligating bracket was used on one side and a conventional bracket on the other . MATERIAL S AND METHODS In 43 patients requiring maxillary premolar extraction , a self-ligating bracket ( Damon3 , SmartClip ) was used on the maxillary canine on one side and a conventional bracket ( Victory Series ) on the other . The teeth were retracted down a 0.018-inch stainless steel archwire , using a medium Sentalloy retraction spring ( 150 g ) . The rates of retraction were analyzed using a paired t-test . RESULTS The mean movement per 28 days for the conventional bracket was 1.17 mm . For the Damon bracket it was 0.9 mm and for the SmartClip bracket it was 1.10 mm . The differences between the conventional and self-ligating brackets were statistically significant : paired t-test , SmartClip , P < .0043 ; Damon3 , P < .0001 ) . CONCLUSION The retraction rate is faster with the conventional bracket , probably because of the narrower bracket width of the self-ligating brackets OBJECTIVE To evaluate the velocity of canine retraction , anchorage loss and changes on canine and first molar inclinations using self-ligating and conventional brackets . MATERIAL S AND METHODS Twenty-five adults with Class I malocclusion and a treatment plan involving extraction s of four first premolars were selected for this r and omized split-mouth control trial . Patients had either  conventional or self-ligating brackets bonded  to maxillary canines r and omly . Retraction was accomplished using 100-g nickel-titanium closed coil springs , which were reactivated every 4 weeks . Oblique radiographs were taken before and after canine retraction was completed , and the cephalograms were superimposed on stable structures of the maxilla . Cephalometric points were digitized twice by a blinded operator for error control , and the following l and marks were collected : canine cusp and apex horizontal changes , molar cusp and apex horizontal changes , and angulation changes in canines and molars . The blinded data , which were normally distributed , were analyzed through paired t-tests for group differences . RESULTS No differences were found between the two groups for all variables tested . CONCLUSIONS Both brackets showed the same velocity of canine retraction and loss of anteroposterior anchorage of the molars . No changes were found between brackets regarding the inclination of canines and first molars INTRODUCTION Our objective was to test the hypotheses that treatment with 2 fixed orthodontic appliances ( SmartClip and Victory ; 3 M Unitek , Monrovia , Calif ) would result in no difference in ( 1 ) the duration of orthodontic treatment or ( 2 ) the number of visits required . METHODS Sixty-six consecutive patients were r and omly allocated to treatment with a self-ligating bracket system ( SmartClip ) or a conventional appliance ( Victory ) . The duration of treatment and the number of visits required in addition to the initial and final peer assessment rating ( PAR ) scores were recorded . The number of teeth extracted during treatment and the frequency of mechanical eruption of canines were also noted . Analyses of covariance were used to assess the influence of bracket type on treatment duration s , visits required , and percentage PAR score reductions . RESULTS Fifty-four ( 81.8 % ) participants completed the study . The duration of treatment was 3 months greater in the group treated with SmartClip . However , bracket type had no statistical influence on treatment duration ( P = 0.076 ) , total visits required ( P = 0.184 ) , or percentage PAR score reduction ( P = 0.255 ) . CONCLUSIONS Neither hypothesis could be rejected . Bracket type did not influence the duration of treatment or the number of visits required . The percentages of PAR score reductions were also unaffected by the choice of appliance 
    Output:
    
Conclusion There is some evidence from this review that both brackets showed the same rate of canine retraction and loss of antero-posterior anchorage of the molars .