***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 evaluate the influence of attachments and interproximal reduction on canines undergoing rotational movement with Invisalign . MATERIAL S AND METHODS In this prospect i ve clinical study , 53 canines ( 33 maxillary and 20 m and ibular ) were measured from the virtual TREAT models of 31 participants treated with anterior Invisalign .  The pretreatment virtual model of the predicted final tooth position was superimposed on the posttreatment virtual model using ToothMeasure , Invisalign 's proprietary measurement software . A one-way analysis of variance ( ANOVA ) ( P < .05 ) compared three treatment modalities : attachments only ( AO ) , interproximal reduction only ( IO ) , and neither attachments nor interproximal reduction ( N ) . Student 's t-tests ( P < .05 ) compared the mean accuracy of canine rotation between arches . RESULTS The mean accuracy of canine rotation with Invisalign was 35.8 % ( SD = 26.3 ) . Statistical analyses indicated that there was no significant difference in accuracy between groups AO , IO , and N ( P = .343 ) . There was no statistically significant difference ( P = .888 ) in rotational accuracy for maxillary and m and ibular canines for any of the treatment groups . The most commonly prescribed attachment shape was the vertical-ellipsoid ( 70.5 % ) . CONCLUSIONS Vertical-ellipsoid attachments and interproximal reduction do not significantly improve the accuracy of canine rotation with the Invisalign system OBJECTIVE Based on our previous pilot study , the objective of this extended study was to compare ( a ) casts to their corresponding digital ClinCheck ® models at baseline and ( b ) the tooth movement achieved at the end of aligner therapy ( Invisalign ® ) to the predicted movement in the anterior region . MATERIAL S AND METHODS Pre- and post-treatment casts as well as initial and final ClinChecks ® models of 50 patients ( 15 - 63 years of age ) were analyzed . All patients were treated with  Invisalign ® ( Align Technology , Santa Clara , CA , USA ) . Evaluated parameters were : upper/lower anterior arch length and intercanine distance , overjet , overbite , dental midline shift , and the irregularity index according to Little . The comparison achieved/predicted tooth movement was tested for equivalence [ adjusted 98.57 % confidence interval ( - 1.00 ; + 1.00 ) ] . RESULTS Before treatment the anterior crowding , according to Little , was on average 5.39 mm ( minimum 1.50 mm , maximum 14.50 mm ) in the upper dentition and 5.96 mm ( minimum 2.00 mm , maximum 11.50 mm ) in the lower dentition . After treatment the values were reduced to 1.57 mm ( minimum 0 mm , maximum 4.5 mm ) in the maxilla and 0.82 mm ( minimum 0 mm , maximum 2.50 mm ) in the m and ible . We found slight deviations between pretreatment casts and initialClinCheck ® ranging on average from -0.08 mm ( SD ± 0.29 ) for the overjet and up to -0.28 mm ( SD ± 0.46 ) for the upper anterior arch length . The difference between achieved/predicted tooth movements ranged on average from 0.01 mm ( SD ± 0.48 ) for the lower anterior arch length , up to 0.7 mm ( SD ± 0.87 ) for the overbite . All parameters were significantly equivalent except for the overbite ( -1.02 ; -0.39 ) . CONCLUSION Performed with aligners ( Invisalign ® ) , the resolvement of the partly severe anterior crowding was successfully accomplished . Resolving lower anterior crowding by protrusion of the anterior teeth ( i.e. , enlargement of the anterior arch length ) seems well predictable . The initial ClinCheck ® models provided high accuracy compared to the initial casts . The achieved tooth movement was in concordance with the predicted movement for all parameters , except for the overbite Clear aligners provide a convenient model to measure orthodontic tooth movement ( OTM ) . We examined the role of in vivo aligner material fatigue and subject-specific factors in tooth movement .  Fifteen subjects seeking orthodontic treatment at the University of Florida were enrolled . Results were compared with data previously collected from 37 subjects enrolled in a similar protocol . Subjects were followed prospect ively for eight weeks . An upper central incisor was programmed to move 0.5 mm . every two weeks using clear aligners . A duplicate aligner was provided for the second week of each cycle . Weekly polyvinyl siloxane ( PVS ) impressions were taken , and digital models were fabricated to measure OTM . Initial and final cone beam computed tomography ( CBCT ) images were obtained to characterize OTM . Results were compared to data from a similar protocol , where subjects received a new aligner biweekly . No significant difference was found in the amount of OTM between the two groups , with mean total OTM of 1.11 mm . ( st and ard deviation ( SD ) 0.30 ) and 1.07 mm . ( SD 0.33 ) for the weekly aligner and biweekly control groups , respectively ( P = 0.72 ) . Over eight weeks , in two-week intervals , material fatigue does not play a significant role in the rate or amount of tooth movement Fifty-one patients were enrolled in this study to explore the treatment effects of material stiffness and frequency of appliance change when using clear , sequential , removable appliances ( aligners ) . Patients were stratified based on pretreatment peer assessment rating ( PAR ) scores and need for extraction s. They were r and omized into 4 treatment protocol s : 1-week activation with soft material , 1-week activation with hard material , 2-week activation with soft material , and 2-week activation with hard material . Patients continued with their protocol s until either the series of aligners was completed , or until it was determined that the aligner was not fitting well ( study end point ) . Weighted PAR score and average incisor irregularity ( AII ) indexes were used to measure pretreatment and end-point study models , and average improvement was compared among the 4 groups . In addition to the evaluation of the 4 treatment groups , comparisons were made of the individual components of the PAR score to determine which occlusal components experienced the most correction with the aligners . The percentages and absolute extraction space closures were evaluated , and papillary bleeding scores before and during treatment were compared . Although no statistical difference was observed between the 4 treatment groups , a trend was noted with the 2-week frequency having a larger percentage of reduction in weighted PAR and AII scores , and greater extraction space closure . Anterior alignment was the most improved component , and buccal occlusion was the least improved . When analyzed by type of extraction , incisor extraction sites had a significantly greater percentage of closure than either maxillary or m and ibular premolar extraction sites . A statistically significant decrease in mean average papillary bleeding score was found during treatment when compared with pretreatment scores , although this difference was not clinical ly significant The purpose of this study was to compare the efficacy of overbite correction achieved by a conventional continuous arch wire technique and the segmented arch technique as recommended by Burstone . The sample comprised 50 adult patients ( age 18 to 40 years ) with deep bites . Twenty-five patients were treated with a continuous arch wire technique ( CAW ) ; in the second half of the sample , the segmented arch technique ( Burstone ) was used for correction of the vertical malocclusion . Lateral cephalograms and plaster cast models taken before and immediately after treatment were evaluated . Statistical analysis was performed on the collected data . The results showed that both techniques produced a highly significant overbite reduction ( CAW : -3.17 mm , p < 0.001 ; Burstone : -3.56 mm , p < 0.001 ) . The CAW group showed an extrusion in the molar area with subsequent posterior rotation of the m and ible ( 6occl-ML : + 1.30 mm ; 6occl-NSL : + 1.63 mm ; ML/NSL : + 1.94 degrees , all p < 0.001 ) . The Burstone group , however , showed overbite reduction by incisor intrusion without any substantial extrusion of posterior teeth ( upper 1-NSL : -1.50 mm ; lower 1-ML : -1.72 mm ; both p < 0.001 ) . As a consequence , no significant posterior rotation of the m and ible took place ( ML/NSL : + 0.52 degrees , n.s . ) . It is concluded that in adult patients the segmented arch technique ( Burstone ) can be considered as being superior to a conventional continuous arch wire technique if arch leveling by incisor intrusion is indicated 
    Output:
    
Extrusion was the most difficult movement to control ( 30 % of accuracy ) , followed by rotation .
CAT aligns and levels the arches ; it is effective in controlling anterior intrusion but not anterior extrusion ; it is effective in controlling posterior buccolingual inclination but not anterior buccolingual inclination ; it is effective in controlling upper molar bodily movements of about 1.5 mm ; and it is not effective in controlling rotation of rounded teeth in particular .