METHODS: Electronic database and hand search of English literature in PubMed, Cochrane Central Register of Controlled Trials, Embase, Web of Science, and clinical trial.gov, with author clarification were performed. The selection criteria were randomized controlled trial (RCT) comparing MOPs with conventional treatment involving both extraction and nonextraction. Cochrane's risk of bias tool and Grading of Recommendations Assessment, Development and Evaluation approach were used for quality assessment. Studies were analyzed with chi-square-based Q statistic methods, I2 index, fixed-effects, and random-effects model. Quantitative analysis was done on homogenous studies using Review Manager.

RESULTS: Eight RCTs were included for the qualitative analysis. Meta-analysis of 2 homogenous studies indicated insignificant effect with MOPs (0.01 mm less OTM; 95% CI, 0.13-0.11; P = 0.83). No difference (P >0.05) was found in anchorage loss, root resorption, gingival recession, and pain.

CONCLUSIONS: Meta-analysis of 2 low-risk of bias studies showed no effect with single application MOPs over a short observation period; however, the overall evidence was low. The quality of evidence for MOP side effects ranged from high to low. Future studies are suggested to investigate repeated MOPs effect over the entire treatment duration for different models of OTM and its related biological changes.

Methods: Electronic and hand searches of English literature in PubMed, Web of Science, Scopus, OpenGrey, and Science Direct were conducted, and the authors were contacted when necessary. Observational studies (population-based, hospital/clinic-based, and cross-sectional) were included. For study appraisal and synthesis, duplicate selection was performed independently by two reviewers. Study quality was assessed using a modified Strengthening the Reporting of Observational Studies in Epidemiology checklist, with main outcome of prevalence of canine agenesis.

Results: The global population prevalence of canine agenesis was 0.30% (0.0-4.7%), highest in Asia (0.54%), followed by Africa (0.33%), and the least in Europe and South America (0.19% in both continents). Canine agenesis was more common in the maxilla (88.57%), followed by both maxilla and mandible (8.57%), and the least common was mandible-only presentation (2.86%). The condition was more common in females (female:male ratio = 1.23), except in Asia (female:male ratio = 0.88) and Africa (female:male ratio = 1). In Asia, unilateral agenesis was almost twice as prevalent as bilateral, but in Europe, the bilateral form was more common.

METHODS: Electronic database search and hand search with no language limitations were conducted in the Cochrane Library, PubMed, Ovid, Web of Science, Scopus and ClinicalTrials.gov. The selection criteria were set to include studies with patients aged 13 years and above requiring extractions of upper and lower first premolars to treat bimaxillary proclination with high anchorage demand. Risk of bias assessment was undertaken with Cochrane's Risk Of Bias tool 2.0 (ROB 2.0) for randomised controlled trials (RCTs) and ROBINS‑I tool for nonrandomised prospective studies. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used for quality assessment. Results were summarised qualitatively; no meta-analysis was conducted.

RESULTS: Two RCTs and two nonrandomised prospective studies were included. According to the GRADE approach, there is low to very low quality of evidence that treatment using mini-implant anchorage may significantly change nasolabial angle, upper and lower lip procumbence, and facial convexity angle compared to treatment with conventional anchorage. Similarly, very low quality evidence exists showing no differences in treatment duration between treatments with skeletal or conventional anchorage.

CONCLUSIONS: The overall existing evidence regarding the effect of anchorage protocols on soft tissue changes in patients with bimaxillary protrusion and premolar extraction treatment plans is of low quality.