EFFICACY AND AESTHETIC EFFECT OF MICROIMPLANTS OF DIFFERENT IMPLANTATION HEIGHTS FOR ANGLE Ⅱ MALOCCLUSION

Jingjing Zhang^{1, 2}, Suqing Qi^{1, 2, *}, Weican Chen³, Chao wang^{1, 2}, Hongwei wang^{1, 2}, Hongwei Hui^{1, 2}

¹Provincial Key Laboratory of Ophthalmology, Hebei Eye Hospital, Xingtai, 054000, China - ²Clinical Medical Research Center for Eye Diseases, Hebei Eye Hospital, Xingtai, 054000, China - ³Department of Stomatology1, Baoding No.1 Central Hospital, Baoding, 071000, China

Objective: This study aims to investigate the efficacy and aesthetic effect of microimplants of different implantation heights for Angle II malocclusion. 

Methods: A total of 66 patients with Angle II malocclusion admitted to the Orthodontics Department of our hospital from January 2015 to January 2020 were selected and divided into group A and group B by using the red and blue ball method, with 33 cases in each group. In both groups, the anterior adduction process was completed by microimplant-assisted straight wire self-locking appliance. The implantation height of microimplant was set at 5mm in group A and 9mm in group B.The teeth occlusal ability, efficacy and aesthetic effect were compared before and after correction. 

Results: The occlusal force was higher in both groups after treatment, showingstatistically significant difference (P<0.05). After correction,the occlusal force was higher in group B than in group A, showing a statistically significant difference (P<0.05). Group B had superior efficacy than group A after treatment, showingstatistically significant difference (P< 0.05). Before correction, there was no significant difference in anterior tooth torque between the two groups (P>0.05). After correction, the U1-FH and U1-SN angles were higher in group B than in group A, showing a statistically significant difference (P<0.05). After correction, the gingival exposure of group B covered the upper incisor by (-1.39±1.25) mm, and the figure was (-0.70±0.85) mm for group A, showingstatistically significant difference (P<0.05). There were no significant differences in U1-PP and nasolabial angle between the two groups (P>0.05). 

Conclusion: Whenmicroimplants with implantation height of 9mm were used for correction of Angle II malocclusion, theocclusal force was greater with better clinicalefficacy and aesthetic effect, so for patients with Angle II malocclusion, 9mm implantation height is ideal.