***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 In a clinical trial involving 155 dental arches with irregularity > 5 mm , the rate of alignment was used to compare the alignment efficiency of 16 mil superelastic Ni-Ti versus 17.5 mil triple-str and ed steel archwires , and to determine whether ion implantation of the Ni-Ti wire improved its performance . Subjects were r and omly assigned to archwire types ; both 18 and 22 slot edgewise appliances were employed . Pre-treatment equivalence of the experimental groups was verified . Anterior irregularity was determined monthly ( using Little 's irregularity index ) until it decreased below 2 mm , and the elastomeric ligatures were replaced at each appointment . Effective tooth movement occurred with each of the archwire types . There were no significant differences among wires , but the rate of alignment was significantly faster in the lower arch for subjects with the 22 slot appliance Two arch wires commonly used for initial tooth alignment were compared with regard to their clinical effectiveness . The two arch wires tested were 0.0155-inch diameter multiple-str and ed stainless steel wire ( Dentaflex , Dentaurium , Optident , Yorkshire , Engl and ) and 0.014-inch diameter nickel-titanium alloy wire ( NiTi , ORMCO Co. , Monrovia , Calif. ) . Consecutive patients attending an orthodontic clinic for routine placement of a fixed appliance were r and omly assigned one of these two initial arch wires . Good quality alginate impressions of the appropriate dental arch were taken before arch wire placement and also at the subsequent appointment , which was , on average , 6 weeks later . Seventy-four arches were used in this study . The degree of tooth alignment achieved for each wire type was compared with a Reflex Microscope ( Reflex Measurement Ltd. , Butleigh , Engl and ) to make detailed measurements on the result ant casts . The degree of initial alignment achieved with the two wires was similar over this 6-week period . However , some differences were found for the lower labial segment where the interbracket span is usually reduced and where the superelastic nickel-titanium wire was found to give improved alignment . No threshold of crowding was found where one arch wire performed better than the other Two nickel-titanium archwire types commonly used for initial tooth alignment were compared with regard to the pain/discomfort patients experience during the initial phase of tooth movement . The two archwires used were a superelastic nickel-titanium alloy , 0.014 inch Sentalloy , Light ( GAC International Inc. Central Islip , NY , USA ) and a 0.014 inch Nitinol ( unitek , Monrovia , CA , USA ) , a conventional nickel-titanium aligning archwire .  One hundred and twenty-eight consecutive patients attending an orthodontic university clinic and 2 private practice s for routine placement of a fixed appliance were r and omly assigned one of these 2 initial archwires . Assessment s of pain/discomfort were made daily by means of a 100 mm visual analog scale ( VAS ) over the first 7-day period after bonding . On the first day , recordings were made every hour for the first 11 hours . The results showed that the level of discomfort increased continuously every hour after the insertion of either a Sentalloy or a Nitinol as first archwires , with a peak in the first night , remaining high on the second day and decreasing thereafter to baseline level after 7 days . During the first 10 hours it was apparent that the pain/discomfort experienced after placement of a Sentalloy was less than that found with the Nitinol archwire , although a significant difference could be found at 4 hours only . No significant gender-specific differences were found in either archwire group . A significant difference between the upper and lower dental arches was observed during the first 11 hours after placement of either a Sentalloy or a Nitinol archwire , with the lower arch having the higher pain experience . ZusammenfassungZwei verschiedene Bögen aus NiTi-Legierungen , die häufig für die initiale Nivellierung verwendet werden , wurden in Hinsicht auf das Auftreten von Schmerzen/Beschwerden zu Beginn der Zahnbewegung untersucht . Das eine Bogen material war eine superelastische NiTi-legierung , 0,014 inch Sentalloy , Light ( GAC International Inc. , Central Islip , N. Y. ) , das and ere ein herkömmlicher 0,014 inch Nitinol-Bogen ( Unitek , Monrovia , Kalifornien).128 fortlaufend beh and elte Patienten aus einer kieferorthopädischen Universitätsklinik und zwei privaten Praxen , bei denen routinemäßig eine Multib and apparatur eingesetzt werden sollte , wurden r and omisiert für den einen oder den and eren Bogen vorgesehen . Die Beurteilungen der Schmerzen/Beschwerden wurden täglich während der ersten sieben Tage nach dem Einsetzen der festsitzenden Apparatur auf einer visuellen Skala von 100 mm Länge ( visual analogue scale , VAS ) vorgenommen . Zusätzlich wurde am ersten Tag für die ersten elf Stunden nach dem Einsetzen stündlich die Schmerzintensität aufgezeichnet . Die Ergebnisse zeigten , daß die Beschwerden für den ersten Bogen , sowohl für den Sentalloy-als auch für den Nitinol-Bogen , kontinuierlich jede Stunde nach dem Einsetzen anstiegen . Der Höhepunkt wurde in der ersten Nacht erreicht , blieb am zweiten Tag auf derselben Höhe und verringerte sich kontinuierlich bis zum siebten Tag auf das individuelle Ausgangsniveau . Während der ersten zehn Stunden war es offensichtlich , daß nach der Eingliederung der Bögen beim Sentalloy-Bogen deutlich geringere Beschwerden auftraten als bei dem Nitinol-Bogen ; dieser Unterschied war jedoch nur für die ersten vier Stunden signifikant . Keine signifikanten Unterschiede der Beschwerden zwischen den Bogen material ien f and en sich hinsichtlich des Geschlechts der Patienten . Ein signifikanter Unterschied wurde zwischen dem Ober- und dem Unterkiefer während der ersten elf Studen nach dem Einsetzen sowohl des Sentalloy- als auch des Nitinol-Bogens beobachtet ; i m Unterkiefer traten deutlich stärkere Beschwerden auf The aim of this study was to compare three orthodontic archwire sequences . One hundred and fifty-four 10- to 17-year-old patients were treated in three centres and r and omly allocated to one of three groups : A = 0.016-inch nickel titanium ( NiTi ) , 0.018 x 0.025-inch NiTi , and 0.019 x 0.025-inch stainless steel ( SS ) ; B = 0.016-inch NiTi , 0.016-inch SS , 0.020-inch SS , and 0.019 x 0.025-inch SS ; and C = 0.016 x 0.022-inch copper ( Cu ) NiTi , 0.019 x 0.025-inch CuNiTi , and 0.019 x 0.025-inch SS . At each archwire change and for each arch , the patients completed discomfort scores on a seven-point Likert scale at 4 hours , 24 hours , 3 days , and 1 week . Time in days and the number of visits taken to reach a 0.019 x 0.025-inch SS working archwires were calculated . A periapical radiograph of the upper left central incisor was taken at the start of the treatment and after placement of the 0.019 x 0.025-inch SS wire so root resorption could be assessed . There were no statistically significant differences between archwire sequences A , B , or C for patient discomfort ( P > 0.05 ) or root resorption ( P = 0.58 ) . The number of visits required to reach the working archwire was greater for sequence B than for A ( P = 0.012 ) but this could not be explained by the increased number of archwires used in sequence The statistical methodology of health research experiments published in Lancet , the New Engl and Journal of Medicine , and Medical Care between 1975 and 1980 for the presence or absence of an error of experimental design and analysis was examined . The error is the result of inappropriately using patient-related observations as the unit of analysis to form conclusions about provider behavior or outcomes determined jointly by patients and providers . The error was present in 20 of 28 ( 71 % ) health care experiments addressing an issue of health provider professional performance . Its usual effect is to increase erroneously the power of an experiment to detect differences between experimental and control groups . It is likely that this type of error could be avoided by the explicit and prospect i ve definition of hypotheses and the population s to which they are intended to pertain Aim To compare the efficiency of  orthodontic archwire sequences produced by three manufacturers . Design Prospect i ve , r and omized clinical trial with three parallel groups . Setting Private orthodontic practice in Caloundra , QLD , Australia Subjects and methods One hundred and thirty‐two consecutive patients were r and omized to one of three archwire sequence groups : ( i ) 3 M Unitek , 0·014 inch Nitinol , 0·017 inch × 0·017 inch heat activated Ni – Ti ; ( ii ) GAC international , 0·014 inch Sentalloy , 0·016 × 0·022 inch Bioforce ; and ( iii ) Ormco corporation , 0·014 inch Damon Copper Ni – Ti , 0·014 × 0·025 inch Damon Copper Ni – Ti . All patients received 0·018 × 0·025 inch slot Victory SeriesTM brackets . Outcome measures M and ibular impressions were taken before the insertion of each archwire . Patients completed discomfort surveys according to a seven‐point Likert Scale at 4 h , 24 h , 3 days and 7 days after the insertion of each archwire . Efficiency was measured by time required to reach the working archwire , m and ibular anterior alignment and level of discomfort . Results No significant differences were found in the reduction of irregularity between the archwire sequences at any time‐point ( T1 : P = 0·12 ; T2 : P = 0·06 ; T3 : P = 0·21 ) or in the time to reach the working archwire ( P = 0·28 ) . No significant differences were found in the overall discomfort scores between the archwire sequences ( 4 h : P = 0·30 ; 24 h : P = 0·18 ; 3 days : P = 0·53 ; 7 days : P = 0·47 ) . When the time‐points were analysed individually , the 3 M Unitek archwire sequence  induced significantly less discomfort than GAC and Ormco archwires 24 h after the insertion of the third archwire ( P = 0·02 ) . This could possibly be attributed to the progression in archwire material and archform . Conclusions The archwire sequences were similar in alignment efficiency and overall discomfort . Progression in archwire dimension and archform may contribute to discomfort levels . This study provides clinical justification for three common archwire sequences in 0·018 × 0·025 inch slot brackets OBJECTIVES To examine whether the transition temperature of Cu-NiTi archwires has an effect on the tooth movement during the alignment phase of orthodontic treatment . DESIGN ' Split mouth ' design in r and omly selected patients . SETTING AND SAMPLE POPULATION The Department of Orthodontics , School of Dentistry , University of Aarhus . Fifteen r and omly selected patients with identical level of irregularity in the alignment phase of their treatment . Experiment Variable - Specially manufactured Cu-NiTi archwires for the upper arch were inserted . These consisted of two separate halves , each with its own transition temperature , respectively  
    Output:
    
There is very weak unreliable evidence , based on one very small study ( n = 24 ) at high risk of bias , that coaxial superelastic NiTi may produce greater tooth movement over 12 weeks , but no information on associated pain or root resorption .
There is insufficient evidence to determine whether or not there is a difference between either thermoelastic or CuNiTi and superelastic NiTi initial arch wires .
AUTHORS ' CONCLUSIONS There is no reliable evidence from the trials included in this review that any specific initial arch wire material is better or worse than another with regard to speed of alignment or pain .
There is no evidence at all about the effect of initial arch wire material s on the important adverse effect of root resorption .
Further well- design ed and conducted , adequately-powered , RCTs are required to determine whether the performance of initial arch wire material s as demonstrated in the laboratory , makes a clinical ly important difference to the alignment of teeth in the initial stage of orthodontic treatment in patients