Failure rates of palatal implants or mini-screws for orthodontic anchorage.

Data sources Medline, Embase, the Cochrane Oral Health Group's Trials Register, CENTRAL, ClinicalTrials.gov, the National Research Register and Pro-Quest Dissertation Abstracts and Thesis databases. Study selection Randomised controlled trials (RCTs) non-randomised, or quasi-randomised controlled trials, prospective and retrospective studies involving the assessment of success or failure of palatal implants or palatal mini-screws for orthodontic anchorage reinforcement were considered.Data extraction and synthesis Two reviewers independently selected the studies, extracted data and assessed risk of bias. A narrative synthesis was presented. Results Twenty-seven studies (four RCTs, 12 prospective and 11 retrospective studies) were included.Conclusions No clinically meaningful difference in failure risk seems to exist between palatal implants and mini-screws, however the quality of the available evidence is very low. The studies included between 9 to 384 palatal implants or mini-screws with follow up period ranging from 2 - 35.6 months (median = 17.9). The risk of failure (18 studies) ranged from 0.0 - 26.1% (median 6.0%). The risk of failure in the four RCTS ranged from 2.5 -26.1% (median = 8.8%).