Evaluation On Expansion Efficiency Of Microimplant-assisted Rapid Palatal Expansion In Treatment Of Maxillary Transverse Deficiency In Adolescents With CBCT

Objective:To analyze and evaluate the expansion efficiency of microimplant-assisted rapid palatal expansion(MAPRE)in the treatment of maxillary transverse deficiency in the adolescents and to provide the reference for the formulation of clinical treatment plan.Methods:The clinical materials of 20 adolescent patients with maxillary transverse deficiency,who received MARPE,were selected;the buccal maxillary width(BMW),palatal maxillary width(PMW),the amount of sutural expansion(SE),the amount of MSE appliance expansion(AE),and the first molar angle(MA)of the patients were detected by cone beam computed tomography(CBCT)before and after treatment.The percentage of bony expansion efficiency,the percentage of alveolar bone bending amount and the remaining percentage of effects were calculated.Results:The opening amount of the appliance expansion of the MSE was6.95 ± 1.30 mm.The expansion of the middle palatal suture at the level of maxillary incisor,canine,first premolar,second premolar and firstmolar respectively were 5.18 ± 1.38 mm,5.26 ± 1.26 mm,5.22 ± 1.36 mm,5.27 ± 1.37 mm and 5.27 ± 1.24 mm.Before and after treatment,the changes of buccal maxillary width(?BMW)at the level of the first premolar,the second premolar and the first molar respectively were 5.28± 1.31 mm,5.56 ± 1.67 mm and 6.42 ± 1.42 mm;before and after treatment,the changes of palatal maxillary width(?PMW)at the level of the first premolar,the second premolar and the first molar respectively were 4.92 ± 1.80 mm,5.62 ± 2.37 mm and 5.58 ± 1.77 mm.After the expansion treatment,the first molar angle(MA)decreased,the buccal maxillary width(BMW)and palatal maxillary width(PMW)increased,and the differences were statistically significant(P< 0.001).The change of the buccal maxillary width(?BMW)at the first molar was larger,compared with the change of the palatal maxillary width(? PMW)at the first molar,the difference was statistically significant(t=3.047,P<0.01);compared with the amount of sutural expansion(SE)at the first molar,the difference was statistically significant(t=9.655,P<0.001).Compared with the change of the buccal maxillary width(?BMW)at the first premolar,the change of the buccal maxillary width(? BMW)at the first molar was larger,and the difference was statistically significant(F=3.261,P<0.05).In the first premolar,the second premolar and the first molar,the percentage of bony expansion efficiency were 74.96%,75.81% and75.83%;the percentage of alveolar bone bending amount were 1.43%,3.96% and 16.39%;the remaining percentage of effects were 23.61%,20.23% and 7.78%.Conclusion:MARPE can effectively open the palatal suture of the adolescent with maxillary transverse deficiency in parallel,and the efficiency of bony expansion is up to 74%.