Success and Failure Rates of Orthodontic Mini-screws: A Systematic Review

Aim: The purpose of the present study was to systematically review the literature on the success and failure of the miniscrews.Materials and Methods: Titles and abstracts in Medline Databases (PubMed) were screened by ۲ reviewers. First result contains ۲۷۳ articles, after search filters they have reached to ۹ articles. All articles were discussed by ۲ reviewers and disagreements were solved.Results: The total success rate were available in all ۹ studies and ranged from ۷۰.۳% to ۹۶%. The number of treated patients were ranged from ۱۵ to ۱۴۱and also the number of miniscrews ranged from ۴۴ to ۲۶۰. The success and failure rates of miniscrews in these ۹ studies had no significant correlation with gender. Statistic methods are different among these clinical trials.Conclusion: It seems that weak consensus exist between bulk of data obtained from different clinical trials. Gender has been mentioned as a predisposing factor for success or failure rate and some article reported more success for male, some for female, and some no difference. Immediate loading has more success rate according to some investigations but many investigators suggest a healing period and delayed loading. Diameter and length of miniscrews and their dispersion factor is another source of inconsistency among authors. Diameters start from (in millimeter) ۱.۲, ۱.۳, ۱.۶-۱.۸ to ۲ mm and length starts from (in millimeter) ۵, ۶,۷,۸ to ۱۰ mm and different success rate is reported for these parameters. Even success or failure rate is described differently among clinicians and it start from stability during first one week, extends to six month and two year. In addition, some authors believe that because of the pool of subjects (large sample with important elements) in retrospective studies, appropriate statistics are Kaplan-Meier survival curves based on rigorous clinical success or failure criteria instead of success or failure rate. 

کلیدواژه ها:

Miniscrews ، Mini-screw ، Miniscrew AND Success ، Miniscrew AND failure ، Orthodontic Anchorage Procedure