***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: The split-mouth design is a popular design in oral health research . In the most common split-mouth study , each of two treatments are r and omly assigned to either the right or left halves of the dentition . The attractiveness of the design is that it removes a lot of inter-individual variability from the estimates of the treatment effect . However , already about 20 years ago the pitfalls of the design have been reported in the oral health literature . Yet , many clinicians are not aware of the potential problems with the split-mouth design . Further , it is our experience that most statisticians are not even aware of the existence of this design . Since most of the critical remarks appeared in the oral health literature , we argue that it is necessary to introduce the split-mouth design to a statistical audience , so that both clinicians and statisticians clearly underst and the advantages , limitations , statistical considerations , and implication s of its use in clinical trials and advise them on its use in practice A prospect i ve r and omized crossover , within-patient , controlled study was performed in 26 healthy patients to test the effect of the prophylactic local use of gauze drain impregnated with chlortetracycline ( Aureomycin 3 % , Lederle ) ointment on postoperative alveolitis formation after surgical removal of 52 bilaterally impacted m and ibular third molars . The teeth were removed on two separate occasions ; on one side drain was inserted in the socket , and on the other side no drain treatment was used for control . The influence on postoperative pain , swelling , and mouth opening ability was investigated . The results indicated a statistically significant reduction ( P = 0.02 ) in the incidence of postoperative inflammatory complications , defined as postoperative alveolitis , from 35 % in the no-drain group to 4 % in the drain group . No statistically significant difference was found between the two treatment methods with regard to pain and mouth opening reduction . There was a significant difference between the drain and no-drain treatment with regard to swelling on the 1st postoperative day in favor of the no-drain method . It is concluded that insertion of a chlortetracycline-impregnated drain may be an effective method for reducing postoperative alveolitis formation but has no beneficial effect on pain , swelling , and mouth opening reduction after impacted m and ibular third-molar surgery PURPOSE To compare the effect of total and partial wound closure techniques on immediate postoperative tissue reactions and complications after m and ibular third molar surgery . PATIENTS AND METHODS This prospect i ve , r and omized , controlled study was carried out at the Department of Oral and Maxillofacial Surgery , National Hospital , Abuja , Nigeria . Patients were r and omly allocated to partial ( group I ) and total ( group II ) wound closure groups . Data were collected on pain , trismus , swelling , and complications experienced by the patients . Data analysis was carried out with SPSS software for Windows ( version 13.0 ; SPSS , Chicago , IL ) and GenStat ( Discovery Edition , 2005 ; VSN International Ltd , Hemel Hempstead , UK ) . RESULTS We studied 82 patients , consisting of 54 female and 28 male patients , with m and ibular third molar teeth impaction . There were 40 patients ( 48.8 % ) in group I and 42 patients ( 51.2 % ) in group II . A statistically significant reduction in facial swelling ( P = .001 ) was found in group I compared with group II , but no difference was recorded for pain and trismus . Group I presented with significant postoperative reactionary bleeding ( P = .007 ) , but no difference was recorded between the 2 groups regarding dry socket and socket infection . CONCLUSION The partial wound closure technique after third molar surgery was considered to be associated with more postoperative morbidity , in view of the distressing nature of reactionary bleeding that was found to be associated with it . However , patients should be adequately informed about the possibility of attendant facial swelling each time the technique of total wound closure is used PURPOSE Postoperative variables such as pain , swelling , and trismus after surgery of the impacted lower third molars are the main concerns of dental clinicians and surgeons . Many authors cl aim that the use of a drain could help control these variables . The purpose of this study was to evaluate the effect of the use of a tube drain in impacted lower third molar surgery . MATERIAL S AND METHODS Fifty-three patients of both genders with bilateral impacted lower third molars comprised our comparative study . The patients were divided into 2 groups : in the first the suture procedure was accomplished using a drain , and in the second the suture procedure was accomplished without a drain . The postoperative pain , swelling , and trismus were evaluated at 24 hours , 72 hours , 7 days , and 15 days . RESULTS In the group in which the drain was used , the control of the swelling variable was statistically significant at 24 and 72 hours ( P < .001 ) in comparison with the group in which the drain was not used . However , pain and trismus were not statistically significant at the evaluation period . CONCLUSION The use of the drain helps to control swelling . However , it had no effect on pain or trismus The aim of this prospect i ve r and omized study was to evaluate the effect of using a rubber drain on postoperative pain , swelling and trismus after lower third molar surgery . Of 100 patients with impacted lower third molars referred for surgical extraction , there were 40 males and 60 females , aged 18 - 40 years ( mean=26+/-6.2SD ) . The patients were r and omly divided into two equal groups . In the experimental group , a Penrose rubber drain was inserted into the extraction socket near the buccal fold after surgery and left for 72 h. The control group was selected using the same criteria and treated under the same surgical protocol as the experimental group , but without use of a rubber drain .  Pain , swelling and trismus were evaluated at 24h , 72 h and 5 days postoperatively in both groups . The results of the study indicate that the use of a rubber drain reduces postoperative discomfort in the form of swelling and trismus after lower third molar surgery , but seems to have no effect on pain PURPOSE The aim of this study was to estimate the frequency of  postoperative complications after m and ibular third molar ( M3 ) surgery  and identify the risk indicators . PATIENTS AND METHODS This was a prospect i ve cohort study of a sample of subjects having at least 1 m and ibular M3 surgically extracted at a teaching hospital in Jordan . The predictor variables were categorized as patient , anatomic , and operative specific . The outcome variables were postoperative complications recorded as present or absent . Bivariate analyses were computed , then a multivariate logistic regression model was used to identify independent predictors for the common postoperative complications . RESULTS The study sample was comprised of 149 patients who had 245 extraction s. The mean age was 21.6 + /- 3.32 years ; 64.9 % were females . In the multivariate logistic regression model , age ( P = .033 , odds ratio [ OR ] = 1.178 ) , M3 side in relation to the h and edness of the operator ( P = .048 , OR = 4.078 ) , and lingual retraction ( P = .001 , OR = 11.293 ) were the variables found as independent predictors for alveolar osteitis . The level of impaction had a significant association with trismus , and operation time acted as an independent predictor for pain ( P < .001 , OR = 1.085 ) . CONCLUSION Postoperative morbidity increases with older age , deeper impaction , M3 side differing from the h and edness of the operator , and longer procedures BACKGROUND Swelling , pain and trismus are undesirable consequences of impacted m and ibular third-molar extraction . The authors conducted a study to evaluate the effectiveness of cryotherapy , the therapeutic use of cold , in reducing undesirable consequences after surgery . METHODS Fourteen patients aged 20 to 28 years comprised the sample . The authors extracted two impacted m and ibular third molars at different times from each patient . Immediately after surgery , the patient underwent cryotherapy on one side for 30 minutes every one and one-half hours for 48 hours when he or she was awake . The patient did not receive cryotherapy on the other side . The authors performed clinical examinations to measure trismus and swelling before surgery , immediately after surgery and 24 and 48 hours after surgery . RESULTS The authors compared both sides for differences in swelling , pain and trismus in each patient . The results showed significant statistical differences in two of the five points that were used to measure the swelling ( Wilcoxon nonparametric signed rank test of linear distances between the angle of the m and ible to the pogonion and to the tragus ) . They found statistical differences between the two sides in relation to the pain ; however , they found no significant differences in relation to trismus . CONCLUSIONS Cryotherapy was effective in reducing swelling and pain in this sample . Despite playing no role in the reduction of trismus , cryotherapy was effective in reducing swelling and pain in this sample , and the authors still recommend it be used . CLINICAL IMPLICATION S Cryotherapy is helpful after third-molar extraction . Further studies need to be conducted that use larger sample s of patients and other types of therapy , such as low-level laser therapy This article introduces the approach of GRADE to rating  quality of evidence .  GRADE specifies four categories-high , moderate , low , and very low-that are applied to a body of evidence , not to individual studies . In the context of a systematic review , quality reflects our confidence that the estimates of the effect are correct . In the context of recommendations , quality reflects our confidence that the effect estimates are adequate to support a particular recommendation . R and omized trials begin as high- quality evidence , observational studies as low quality . " Quality " as used in GRADE means more than risk of bias and so may also be compromised by imprecision , inconsistency , indirectness of study results , and publication bias . In addition , several factors can increase our confidence in an estimate of effect . GRADE provides a systematic approach for considering and reporting each of these factors . GRADE separates the process of assessing quality of evidence from the process of making recommendations . Judgments about the strength of a recommendation depend on more than just the quality of evidence Primary and secondary closure techniques after removal of impacted third molars were compared in terms of post-operative pain and swelling .  Two hundred patients with impacted third molars were r and omly divided into two groups of 100 . Panoramic radiographs were taken to assess degree of eruption and angulation of third molars . Teeth were extracted , and in Group 1 the socket was closed by hermetically suturing the flap . In Group 2 a 5 - 6 mm wedge of mucosa adjacent to the second molar was removed to obtain secondary healing . Swelling and pain were evaluated for 7 days after surgery with the VAS scale . The statistical analysis ( * analysis of variance for repeated measures , P < 0.05 ) showed that pain was greater in Group 1 , although it decreased over time similarly in the two groups ( P = 0.081 , F(6,198 ) = 3.073 * ) . Swelling was significantly worse in Group 1 ( P < 0.001 , F(6,198 ) = 44.30 * ) . In Group 1 , dehiscence of the mucosa was present in 33 % of patients at day 7 , and 2 % showed signs of re-infection with suppurative alveolitis at 30 days . Pain and swelling were less severe with secondary healing than with primary healing The insertion of a small surgical tube drain with primary wound closure ( drain group ) was compared to a simple primary wound closure ( no drain group )  after removal of impacted third molars . Surgery was performed on 23 patients in a r and omized cross-over fashion . The operation time was found to be significantly longer and mouth opening significantly wider in the immediate postoperative period in the drain group subjects as compared to the no drain group ( P > or = 0.01 ) . There was no significant difference in the severity of pain between the two groups . Facial swelling was found to be significantly less in the drain group subjects ( P > or = 0.01 ) . The number of patients with wound breakdown , edema , and bleeding was found to be less in the drain group than in the no drain group . Thus , the postoperative problems , in general , were less in the small surgical drain group as compared to the no drain group Extraction of impacted m and ibular third molars is one of the most common procedures in the oral cavity and often is followed by pain , swelling , and post extraction alveolitis and trismus . It has been suggested that postoperative discomfort is in relation to the type of surgical wound healing . The aim of this study was to compare pain , swelling , and maximum mouth opening in two groups of patients with primary and secondary wound healing after impacted m and ibular third molar surgery . Thirty-two patients were enrolled in this study and r and omly divided into two equal groups , quantitatively and by gender . After the surgical procedures , 16 patients received  primary wound closure , while the other 16 participants received  secondary wound closure . A visual analog scale was used to collect pain data three days after the surgeries . A checklist was used to record data regarding swelling size and maximum mouth opening before , immediately following , three days after , and one week after surgery . Frequency tests and a t-test were used for statistical analysis and a P value of < 0.05 was considered to be statistically significant . Patients in the secondary wound healing group showed statistically significant lower discomfort regarding pain , swelling size , and maximal mouth opening compared to the primary wound healing group . The authors suggest the use of secondary wound healing closure to reduce postoperative complications such as pain , maximal mouth opening , and swelling size after impacted m and ibular third molar extraction PURPOSE Pain , swelling , and trismus are the most common complications associated with third molar surgery . Several 
    Output:
    
The results do not support a preference for either approach