# Complications Arising Due to Orthodontic Treatment--A Systematic Review and Meta-Analysis
## 3 Results  
After the initial search strategy was completed, we encountered 634 papers pertinent to the study's objectives. In the second step, 416 articles remained after removal of duplicate studies/studies that were common with one another. Ultimately, in the final selection phase, 14 articles were generated after the application of all the inclusion and exclusion criterion. Thirty studies were selected for the review, and their demographic characteristics were assessed in Table 1. The sample size ranged from 50 to 300, with no definitive parameters related to the age of the participants assessed across the studies. The male-to-female ratio was fairly balanced across the studies, ranging from 1:1.1 to 1:1.3. Out of these fourteen articles, one was a randomized control trial [24], four happened to be retrospective studies [17; 20; 21; 26], one was a comparative study [18], three studies were of cross-sectional design [19; 28; 29], three studies were observational in protocol [22; 23; 25], and the remaining two utilized a questionnaire as their methodological approach [27; 30]. The forest layouts from the 14 studies that were considered for the analysis are shown in Figures 3-5. After considering all pertinent factors related to the papers, the data were entered into the RevMan 5 software, and forest plots displaying the odds ratio, risk ratio, and risk difference related to the effect of the specific complication encountered in the respective study were produced and assessed. The meta-analysis employed a random effects model with a 95% confidence range. For each investigation, the total sample size was the total number of events, and a random effects model was applied. Figure 3 displays the forest plot of the odds ratio obtained through the meta-analysis of clinical trials [17; 18; 19; 20] that examined the impact of orthodontic complications on patients undergoing orthodontic treatment. The odds ratio was found to be 0.51 [0.33, 0.79], indicating that the intervention may be effective in reducing the risk of complications in the study population. The odds ratio of less than 1 suggests that patients who received the intervention (which differed from study-to-study as per the complication that was observed) had lower odds of experiencing orthodontic complications compared to those who did not receive the intervention. The confidence interval for the odds ratio ranged from 0.33 to 0.79, suggesting that the true effect size is likely to fall within this range. However, the wide range of the confidence interval indicates that the true effect size is uncertain. The heterogeneity statistics reported in the forest plot indicate that there is significant variation in the effect sizes reported across the studies included in the meta-analysis. The Tau\({}^{2}\) value of 0.56 suggests that there is substantial heterogeneity between the studies, while the Chi\({}^{2}\) value of 97.76, with 12 degrees of freedom and a \(p\)-value of \(<\)0.00001, indicates significant heterogeneity. The l\({}^{2}\) value of 88% indicates that a large proportion of the heterogeneity is due to true differences in effect sizes. The test for overall effect, with a \(Z\)-value of 2.99 and a \(p\)-value of 0.003, indicates that the overall effect of the intervention on reducing orthodontic complications is statistically significant. Overall, the forest plot suggests that the intervention may be effective in reducing the risk of orthodontic complications in patients undergoing orthodontic treatment. However, the wide confidence interval and significant heterogeneity highlight the need for further research to confirm the intervention's effects and explore the sources of heterogeneity. Figure 5. Risk difference of clinical trials [17, 18, 19, 20] selected in this systematic review and the impact of complications reported within them, displayed on a forest plot after meta-analysis.