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Comparison of effectiveness of quad helix appliance with other slow maxillary expanders in children with posterior crossbite: A systematic review

Objective: The present review was conducted to compare the effectiveness of Quad Helix (QH) appliance with other slow maxillary expanders in children with posterior crossbite. Materials and Methods: Randomized controlled clinical trials and retrospective studies published between January 1, 1995, and December 31, 2016, were identified from MEDLINE, the Cochrane Central Register of Controlled Trials, the National Institutes of Health Trials, Clinical Trials Registry India, Google Scholar and major journals. After a comprehensive search, the articles were independently screened for eligibility by two reviewers. All cross-reference lists of the selected studies were screened for any additional papers. Results: The preliminary screening consisted of 608 articles, of which 33 articles were selected. A final total of only 9 articles were included as they met the inclusion and exclusion criteria. Of the nine papers, four articles clearly state that QH appliance was a more effective appliance, while the remaining five studies suggest that the maxillary expansion caused by QH is comparable to other slow maxillary expansion appliances. Of the nine included articles, four articles also describe the complications of QH in comparison to other slow maxillary expansion devices. Conclusion: The QH appliance is a viable alternative for the correction of posterior crossbite. The QH appliance is comparable to or even better than other slow maxillary expanders in terms of maxillary expansion while being cost-effective with very few complications.