Clinical Study On The Application Of Micro-implant In The Treatment Of Class ?/? BMD Malocclusion

Objective: Investigate the effectiveness of micro-implant anchorages in advancing the anterior teeth,closing the extraction space,and treating severe dentition congestion in the straight wire arch correction technique,and provide guidance for patients with class?/?BMD malformations who require strong anchorage in clinical treatment.Methods: Twenty-five patients with maxillary anterior processes,bimaxillary processes,and crowded dentition were classified as class ?/? BMD,and X-ray skull positioning lateral radiographs were taken before and after treatment,which were analyzed by Hwaseo comprehensive analysis and Burstone soft tissue analysis.SPSS23.0 statistical software was used to analyze the measurement results.The normality test(momentum method)was performed on the difference between the data before and after treatment.According to the normality of the difference,the paired T test or Wilcoxon paired symbol rank sum test was selected.The correlation between soft and hard tissue changes was analyzed by Pearson correlation.Results: 1.The experiment showed that the average time from the implantation of the microimplant to the complete closure of the extraction space was(9.52±1.13)months,and the success rate of the micro-implant was 96%.2.Bone hard tissue change results: SNA angle decreased by(1.10±2.05)°,ANB angle decreased by(0.83±1.65)°,OP-SN angle decreased by(1.14±1.75)°(P<0.05);There was no significant difference between the SNB angle and the FH-MP angle before and after treatment(P>0.05),indicating that the maxillary protrusion decreased after the treatment,the anterior alveolar bone moved with the adduction of the teeth,and the occlusal plane and mandibular plane were favorable controlled.3.Tooth and alveolar bone change results: U1-SN angle increased(5.70 ± 4.24)°,U1-NA angle decreased(5.32 ±6.43)°,U1-NA distance decreased(2.73±2.69)mm,U1-PP distance decreased by(2.42±3.34) mm,Very significant difference before and after correction(P<0.01);U6-Ptm distance and U6-PP distance was not significantly difference before and after treatment(P>0.05).There was obvious adduction in the sigmoid direction and depression in the vertical direction.The maxillary first molar was favorably controlled in the sagittal direction.4.Soft tissue changes after correction: Nasolabial angle(NLA)increased(9.15±5.15)°,The UL-E distance decreased by(1.44±0.94)mm,Very significant difference before and after correction(P<0.01);facial protrusion angle(G-Sn-Pog angle)decreased(2.75±4.20)°,Significant difference before and after correction(P<0.05).It indicates that the upper lip soft tissue was adducted,the distance from the upper lip protrusion point to the E line was reduced,the facial soft tissue protrusion was reduced,and the profile was improved.Conclusion: The use of microimplants could provide stable anchorage for patients with type?/? bone mineral density malocclusion.The position of the upper and lower jaw improved after correction,and the occlusal and mandibular planes were favorably controlled.The upper anterior teeth were significantly adducted in the sagittal direction and depressed in the vertical direction;first maxillary grinding was favorably controlled in the sagittal direction;the profile of the soft tissue was improved.