Comparison Of The Effects Between Mini-implant And Headgear For The Patients With Protrusion

Objective: To analysis the effects of the mini-implant and the headgearfor patients with maxillary protrusion or bimaxillary protrusion.Providingdecision-making for the orthodontist.Method:Retrievalling relevantdatabase: Cochrane library(2009Issue4)、MEDLINE、EMBASE、ISI Webof science、Science Direct、CBM、VIP、CNKI and Wangfang,while manualsearch Campbell Library、NLM、WHOLIS and Evidencebased medicion,Journal of Orthodontics.Referring to articles. Study selection,methodological quality assessment, and data extraction were performed bytwo reviewers independently. The software RevMan5.1.2was used todetecting the experimental design, interventions and outcomes. Metaanalysis was performed by way of choosing the fixed or random modelaccording to the heterogeneity, and description analysis was used for paperunable to carry out meta analysis. Results:According to the exclusionStandard,this research eventually included13ariticles for metaanalysis,including8RCTs trials and5CBAs trials. Reference “Jadad scale”and “the randomized controlled trials quality assessment form” to evaluate the quality of the trials.3RCTs trials are high quality and5RCTs trials arelow quality.1CBAs trials is class C and4are class B.Including high qualitytrials into Meta analysis respectively. Including209patients in all:72RCTspatients,including36mini-inplant anchorage patients and36headgearanchorage patients;137CBAs patients,including70mini-inplant anchoragepatients and67headgear anchorage patients.Mini-implant anchorage isexperiment group and the headgear anchorage is control group. Two groupsin SNA°show no statistically significant differences in RCTs trials（P=0.085）. The Meta analysis of the4CBAs show that homogeneity isgood （P=0.23,I2=31%）， WMD and95%CI is：0.32[0.07,0.56],astatistically significant difference（P=0.01）.In SN-MP°group，The Metaanalysis of the3CBAs show that heterogeneous is large（P=0.003,I2=83%），the results of the sensitivity analysis and the sub-group analysis showthat:The heterogeneous of1trials is larger than2other trials. Thehomogeneity of the high angle group and the low angle group are bothgood.The difference in high angle group shows significant difference（P=0.002）；But the difference in low angle group shows no significantdifference（P=0.18）。In U1-SN°group,including3RCTs trials and3CBAstrials, the results of the Meta analysis show respectively: The Meta analysisof the3RCTs show that the heterogeneous in1trials is larger than2othertrial（sP<0.0001,I2=90%）.The result of the2other RCTs trials is that the twogroups show significant difference（P=0.0008）,means that the mini-implant anchorage is better than headgear anchorage in U1-SN°. However, The Metaanalysis of the3CBAs show that homogeneity is good（P=0.17,I2=43%）,WMD and95%CI is：-2.61[-5.05,-0.17], two groups show significantdifference（P=0.04）.The result of the age sub-group analysis show that theages in mini-implant anchorange group are larger than that in headgearanchorange group,meanwhile, two groups show significant difference（P=0.004）。However,only1article involves NLA°,UL-E Line(mm) andG-Sn-Pg°,the results of the research are that:The two group in UL-ELine(mm) shows significant difference （P=0.028）and that in NLA°G-Sn-Pg°show no significant difference（P=0.123，P=0.818）.Conclusion: Forthe patients with maxillary protrusion or bimaxillary protrusion,themini-implant anchorage and the headgear anchorage both can achieve goodresults. However,mini-implant anchorage is much better than headgearanchorage in UL-E Line(mm).Meanwhile,especially for high anglepatients,mini-implant anchorage can make mandible counterclockwiserotation effectively. However,there is no exact conclusion in U1-SN°,SNA°,NLA°and G-Sn-Pg°,because of the quality and the quantity of includingtrials is limited. More qualified RCTs are required to provide betterrecommendations.