The Efficacy And Stability Of Miniscrew Assisted Rapid Maxillary Expansion: A Systematic Review

Objective:The purpose of this study is to systematically evaluate the clinical efficacy and stability of maxillary transverse deficiency(MTD)in the treatment of miniscrew assisted rapid maxillary expansion(MARME)through meta-analysis,and to provide a reference for the determination of clinical treatment plans for such patients.Methods:Retrieve the following databases by computer:Cochrane Library,PubMed,Embase,Web of Science,CNKI,Wanfang Database,and CBM.Then comprehensively collect the Chinese and English studies related to miniscrew assisted rapid maxillary expansion and published before December 31,2017.The two researchers searched for the retrieved literature according to the predetermined inclusion and exclusion criteria,and evaluated the quality of randomized controlled trials(RCT)and non-randomized controlled trials(NRCT)respectively based on the quality evaluation criteria(introduced in the Cochrane System Reviewer's Manual,Version 5.1.0.)and methodological index for nonrandomized studies(MINORS).The data was analyzed by using RevMan 5.3 software.The weighted mean difference(WMD)and 95%confidence interval(CI)were combined in the effect size.For studies that cannot be meta-analyzed,descriptive analysis is used.Results:This study eventually included 10 articles,including 9 NRCTs and 1 RCT,with a total of 158 patients.The quality evaluation results showed that 7 articles were of medium quality and 3 articles were of high quality.The results of Meta-analysis showed that:1.The changes before and after MARME:The maxillary first intermolar width(U66)increased by approximately 6.57mm,with a statistically significant change(WMD=6.57,95%CI:4.77?8.38,P<0.0001),and the heterogeneity between the studies was moderate(P=0.12,I2=53%);the intermaxillary width of the maxillary first molar area(UA66)increased by about 2.62mm,with a statistically significant change(WMD=2.62,95%CI:0.73-5.51,P=0.0006),and the homogeneity between the studies was good(P=0.78,12=0%);the nasal cavity width increased by approximately 2.16mm,with a statistically significant(WMD=2.16,95%CI:0.59-3.72,P=0.0007),and the heterogeneity between the studies was moderate(P=0.11,I2=55%);the changes in the width of anterior nasal spine(ANS)and posterior nasal spine(PNS)are similar.and there was no significant difference between them(WMD=0.53,95%CI:-0.04?1.10,P=0.07),and the homogeneity between studies was good(P=0.88,I2=0%);the buccal alveolar crest height of the maxillary first molar and the homogeneity between studies was good(U6)decreased by about 1.04mm,with a statistically significant change(WMD=-1.04,95%CI:-1.92?-0.16,P=0.02)and good homogeneity between studies(P=0.35,I2=4%);left and right maxillary first molars(UL6,UR6)showed little difference in buccal inclination,with no statistically significant difference between the two(WMD=0.02,95%CI:-0.67-0.71,P=0.96),.and the homogeneity between studies was good(P=0.91,I2=0%).2.The long-term changes after MARME:U66 decreased by approximately 1.56 mm during a one-year follow-up period,with statistically significant changes(WMD=-1.56,95%CI:-2.42?-0.70,P=0.0004),and the homogeneity among studies was good(P=0.46,I2=0%);UA66 decreased by approximately 0.55mm during a one-year follow-up period,with a statistically significant change(WMD=-0.55,95%CI:-1.03?-0.07,P=0.002),and the homogeneity among studies was good(P=0.74,I2=0%);U6 buccal inclination decreased,with statistically significant changes(WMD=-3.04,95%CI:-4.49 to-1.59,P<0.0001),and the homogeneity among studies was good(P=0.54,I2=0%).The descriptive analysis results show:the success rate of MARME was higher in young adult patients and there were fewer side effects compared with the dental support group;although the maxillary posterior alveolar bone thickness and height decrease after MARME,it increases during the one-year follow-up period,and the overall amount of reduction was slight.After the MARME,the alveolar bone in the upper posterior region showed a certain degree of buccal inclination,but the change of buccal inclination was smaller than that of the dental support group.In the horizontal plane,the midline sutures open up nearly parallel but on both sides the separation has asymmetry;in the coronal plane,the expansion is in the form of a triangle with a narrow width at the top.Conclusions:1.MARME is an effective method for the treatment of maxillary transverse deficiency.It breaks through the age limitation of the traditional rapid maxillary expansion and can still achieve better bone expansion effect for late growth and young adult patients.And the side effects like teeth buccal and alveolar bone height reduction decreased.2.After a long period of MARME,the alveolar bone can be reconstructed with the change of the position of the teeth,and the long-term stability of MARME is quite good.3.In the horizontal plane,the midline sutures open up nearly parallel and the expansion is asymmetric;in the coronal plane,the expansion is in the form of a triangle with a narrow width at the top.4.MARME has advantages in patients with missing maxillary posterior teeth or other reasons that cannot be used as anchorage teeth,severe maxillary transverse deficiency,and high-angle cases;and the MARME device does not affect the placement of the fixed appliances so that can immediately start fixed orthodontic treatment after the completion of the expansion,shortening the total course of treatment of the patient.