***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: PURPOSE To compare the early psychological changes of cleft lip and palate ( CLP ) and noncleft patients after maxillofacial corrective surgery , including maxillary distraction osteogenesis and conventional orthognathic surgery .  MATERIAL S AND METHODS Nine CLP patients were compared with a group of 9 non-CLP patients having similar dentofacial deformities in a prospect i ve longitudinal cohort study . Five of the CLP patients underwent maxillary distraction osteogenesis and 4 underwent conventional orthognathic surgery . A control group of 9 noncleft patients received conventional orthognathic surgery . All patients completed a set of question naires to enable their psychological profile to be assessed . The data were collected immediately before surgery ( T1 ) , and at 3 weeks ( T2 ) and 12 weeks ( T3 ) after surgery . RESULTS The CLP patients treated with distraction osteogenesis were happier , but had a higher level of social anxiety and distress than the CLP patients receiving conventional orthognathic surgery . On the other h and , the CLP patients overall were happier , with lower social anxiety and distress , than the noncleft control group . The CLP patients showed a higher level of parental self-esteem than the noncleft patients . CONCLUSION This preliminary study shows that CLP patients were generally happier , and had a higher level of parental support , than normal patients suffering from dentofacial deformities . Maxillary distraction osteogenesis seemed to induce a higher level of anxiety and distress in CLP patients than conventional orthognathic surgery in both cleft and noncleft patients Fourteen children , aged 8 to 13 years , with unilateral or bilateral cleft lip and palate , were treated by an incomplete Le Fort I osteotomy without down-fracturing the maxilla , followed by traction of the maxilla by face mask for twelve weeks . Our results revealed a mean maxillary forward movement of 7.2 mm after three weeks of traction , followed by a retention period of nine weeks for callus maturation . There was an associated minor downward movement of the maxilla that caused a slight increase in the lower facial height , which improved the facial esthetics of the patients . The advantages of this method are : i ) it allows for early skeletal advancement of the maxilla with new bone formation in the osteotomy line , ii ) there is no need for inter-maxillary fixation of young patients and no need for rigid fixation of the maxilla by miniplates that can damage teeth buds and roots at this age , and iii ) it can be used in young patients to improve esthetic appearance , an important factor in the psychological development of adolescents OBJECTIVE The objective of this study was to compare the psychological changes of patients with cleft lip and palate ( CLP ) undergoing maxillary Le Fort I advancement by distraction osteogenesis ( DO ) and conventional orthognathic surgery ( CO ) .  STUDY DESIGN Prospect i ve r and omized controlled study . Participants completed a set of question naires to measure their psychological states preoperatively and postoperatively . RESULT When compared with CO , CLP patients treated with DO had lower social self-esteem and higher social avoidance and distress levels during the first 3 postoperative months . Their self-esteem , social avoidance , and distress levels improved after the distractors were removed . Both CO and DO patients had similar levels of self-esteem , social avoidance , and distress levels 2 years postoperatively . The CLP patients treated with DO were more satisfied with their lives after 2 years . CONCLUSIONS DO may induce short-term distress to patients up to 3 months but CLP patients who received DO were more satisfied with their lives in the long term PURPOSE Conventional maxillary distraction osteogenesis and anterior maxillary segmental distraction were applied in the treatment of severe maxillary hypoplasia secondary to cleft clip and palate . The aim of the present study was to compare the difference between these 2 osteotomy modalities used for rigid external distraction . PATIENTS AND METHODS Ten patients with severe maxillary hypoplasia secondary to CLP were enrolled in our study . They were r and omly divided into 2 groups . Conventional maxillary distraction osteogenesis was performed in 5 patients and anterior maxillary segmental distraction in 5 patients . The preoperative and postoperative lateral cephalograms were compared , and cephalometric analysis was performed . The independent sample t test was used to evaluate the differences between the 2 groups . RESULTS All patients healed uneventfully , and the maxillae moved forward satisfactorily . The sella-nasion-point A angles , nasion-point A-Frankfort horizontal plane angles , overjets , and 0-meridian to subnasale distances had increased significantly after distraction osteogenesis . Significant differences were found in the changes in palatal length between the 2 groups ( P < .05 ) . A mean increase of 7.50 mm in palatal length was found in the anterior maxillary segmental distraction group . No significant difference in the changes in palatopharyngeal depth or soft palatal length was found . CONCLUSIONS With the ability of increasing the palatal and arch length , avoiding changes in palatopharyngeal depth , and preserving palatopharyngeal closure function , anterior maxillary segmental distraction has great value in the treatment of maxillary hypoplasia secondary to CLP . It is a promising and valuable technique in this potentially complicated procedure PURPOSE The purpose of this study was to investigate the changes in and stability of the maxilla and soft tissue profile achieved after the application of distraction osteogenesis ( DO ) by use of rigid external distraction ( RED ) with a retention plate system in unilateral cleft lip and palate ( UCLP ) adult patients . We compared 2 treatment methods in the management of maxillary hypoplasia : Le Fort I osteotomy and DO . MATERIAL S AND METHODS Six UCLP adult patients who underwent treatment with the RED retention plate system were examined ( DO group ) .  Changes in the positions of soft and hard tissue l and marks were calculated from lateral cephalograms taken before distraction , at the removal of the halo , and 1 year after surgery and were compared with those in 7 other UCLP patients who underwent Le Fort I osteotomy ( LF1 group ) . RESULTS The mean maxillary advancement was significantly larger in the DO group than in the LF1 group after distraction . During the follow-up period , the relapse rate of the maxilla was significantly smaller in the DO group . An undesirable labial inclination of the upper incisors was found in the LF1 group , which may have been due to relapse . The DO group tended to have a higher soft tissue-to-hard tissue anterior movement ratio from the time of distraction to follow-up . CONCLUSIONS The RED retention plate system improved the midfacial profile by advancement of soft and hard tissue and minimized the risk of injury to the upper lip . Using the RED system with retention plates prevented the undesirable labial inclination of upper incisors that was found in the LF1 group Objective To undertake a critical and systematic review of the literature on the impact of maxillary advancement on speech outcomes in order to identify current best evidence . Design and Main Outcome Measures The following data bases were search ed : PubMed , CINAHL , and The Cochrane Controlled Trials Register . In addition , reference lists were h and search ed for additional articles . Using a predefined framework and set criteria , evidence was evaluated using the assignment of levels of evidence ( at least Level III on the evidence hierarchy ) , calculation of post-hoc power ( ≥ 0.8 ) , effect size ( Cohen 's d ≥ 0.5 ) , and adaptation of the parameters as set out by The Cochrane Collaboration . Results Of the 40 studies identified , the majority ( 68 % ) fell within Level lll.ii , representing cohort-type studies and a fifth ( 20 % ) within Level IV , the weakest form of evidence . Power and effect size calculations were only possible in 9 studies for different speech outcomes , and only seven studies met the set criteria for best evidence . Accordingly , current best evidence for articulation exists only for a noncleft population , is conflicting for resonance and nasalance , and is mixed for velopharyngeal function depending on which instrumental measure is used . Conclusions There is an obvious need for further prospect i ve research in the field with strong speech methodology such as the undertaking of interrater and intrarater reliability , adequate follow-up , and sufficient sample sizes based on a priori power analyses . Method ologic issues are discussed and recommendations made PURPOSE The objective of this r and omized controlled clinical trial was to compare the soft tissue changes after maxillary advancement using conventional orthognathic surgery ( CO ) and distraction osteogenesis ( DO ) in patients with cleft lip and palate ( CLP ) . MATERIAL S AND METHODS The study group of 39 CLP patients with maxillary hypoplasia underwent either CO or DO with 4 to 10 mm of maxillary advancement .  Lateral cephalographs were taken preoperatively and postoperatively at regular intervals . A series of skeletal , dental , and soft tissue l and marks was used to evaluate the changes in the soft tissue and the correlation of hard and soft tissue changes and ratios . RESULTS Significant differences were found between the CO and DO patients at A point in both maxillary advancement and downgrafting in the early follow-up period . On soft tissue l and marks of pronasale , subnasale , and labial superius , significant differences were found between the 2 groups at 6 months postoperatively only with maxillary advancement . There was better correlation of hard and soft tissue changes with maxillary advancement . The nasal projection was significantly different between the 2 groups at the early and intermediate period . There was much more consistent hard to soft tissue ratios in maxillary advancement with DO than with CO . CONCLUSIONS Both CO and DO can induce significant soft tissue changes of the upper lip and nose , particularly with maxillary advancement . DO generates more consistent hard to soft tissue ratios 
    Output:
    
DO offered better stability .
No clear evidence exists on which technique had the best aesthetic results and functional improvement .
DO may cause higher levels of anxiety and distress in patients compared to CO .