The Efficacy Of Bone-borne Expander And Tooth-borne Expander In Surgically Assisted Rapid Maxillary Expansion:A Systematic Review

Objective:The purpose of this study is to systematically evaluate the clinical efficacy of bone-borne expander(BB)and tooth-borne expander(TB)in surgically assisted rapid maxillary expansion(SARME)through meta-analysis.Aim to provide a reference for the determination of clinical treatment plan for patients with maxillary transverse deficiency(MTD).Methods:The Chinese and English clinical studies related to the bone-borne expander and tooth-borne expander in surgically assisted rapid maxillary expansion were searched by computer and published before December 31,2018.The database includes Cochrane Library(CL),PubMed,Web of Science,Dutch Medical Abstracts Database(Embase),Scopus Database,Chinese Academic Journals Full-text Database(CNKI),Chinese Biomedical Literature Database(CBM)and Wanfang Data(Wanfang).Two researchers independently selected the retrieved documents according to the predetermined inclusion and exclusion criteria,and evaluated the quality based on the Cochrane risk bias evaluation tool of the random control test(RCT)and the methodological evaluation index of the non-random control test(MINORS)in the Cochrane system evaluation manual.The data of meta-analysis was analyzed by Revman 5.3 software.The weighted mean difference(WMD)and 95%confidence interval(CI)were selected as the effect size.According to the heterogeneity test result,different effect model were combined.The others studies which could not be meta-analyzed were evaluated by descriptive analysis.Results:459 studies were searched and eventually 7 studies were included,of which 2 randomized controlled trials and 5 non-randomized controlled trials,totally 266 patients,134 patiens using bone-borne expander after surgical'assisted maxillary rapid expansion and 132 patiens using tooth-borne expander.The quality evaluation results showed that 6 ranked as medium quality and 1 ranked as low quality.The results of the meta-analysis showed that bone-borne expander and the tooth-borne expander in SARME both can achieve significant expansion effects in the width changes of the teeth and palatal.Among them,the width change between maxillary canines was bigger by using the bone-borne expander after the SARME than the tooth-borne expander,and it was statistically significant(WMD=1.28,95%CI:0.23-2.33,P=0.02).There was no significant difference in the width changes of the teeth and the width of palatal of the remaining posterior teeth(P>0.05).Both bone-borne expander and tooth-borne expander in SARME caused significant inclination of posterior teeth and vertically buccal bone absorption.Among them,the change of inclination of the maxillary first premolar by using tooth-borne expander was more obvious compare to bone,borne expander in the SARME(WMD-=-1.04,95%CI:-1.97?-0.11,P=0.03).In addition,there was no significant difference between tooth-borne expander and bone-borne expander in the inclination of the teeth and the vertically buccal bone absorption of the remaining posterior teeth(P>0.05).Descriptive analysis showed that bone-borne expander and the tooth-borne expander in SARME both can achieve significant expansion effects in the width of maxillary and nasal floor.The expansion pattern of using bone-borne expander is a V-shape,while the expansion pattern of using tooth-borne expander is more parallel.Significant alveolar segmental inclincation occurred in both kinds of expanders,with similar degrees of inclination.Follow-up studies have shown that no serious complications occurred in tooth-borne expander or bone-borne expander,and there is no significant difference in the presence of complications between them.Conclusions:(1)SARME is an effective method to treat skeletal mature patients with maxillary transverse deficiency.Using the bone-borne expander and tooth-borne expander in SARME both can achieve significant expansion effects in the width of the teeth,palatal,maxillary and nasal base.(2)Using the bone-borne expander and the tooth-borne expander in SARME has similar effects at premolar and molar,in the width changes of the teeth(except for canies),the width changes of palatal,maxillary and nasal base.The width change between maxillary canines is more obvious by using the bone-borne expander after the SARME than the tooth-borne expander.(3)As for the expansion pattern,using the tooth-borne expander in SARME can achieve more parallel expansion effect,while using the bone-borne expander can achieve a V-shape expansion effect with opening forward.However,a more parallel expansion effect can be achieved by surgically separating the resistance of the posterior part of the maxillary and adjusting the position of the bone-borne expander backward.(4)Both bone-borne expander and tooth-borne expander in SARME can cause inclination of posterior teeth and alveolar segmental.Except for tooth-borne expander cause more buccal inclination at first premolar,there is no significant difference in the degree of inclination of remaining posterior teeth and alveolar segmental by using the tooth-borne expander and bone-borne expander in SARME.(5)There is no significant difference in attachment loss and alveolar bone remodeling between TB and BB in SARME.And there is no significant difference in the performance of complications between them.(6)The choice of using tooth-borne expander or bone-borne expander in SARME should not only be based on the requirements of each patient,but also comprehensively considere to the periodontal condition of patient,required expansion pattern,duration of treatment and economic condition.(7)The research about the impact of nasal cavity,airway,tongue position and general health by using the bone-borne expander and tooth-borne expander in SARME,and the difference about long-term stability of them,still need to be evaluated through more high-quality clinical studies.