Study On The Stability And Safety Of Micro Implant Anchorage In Maxillary Posterior Interdental Area Of Adult Skeletal Class ? Malocclusion By Cone Beam CT

Objective:The goal of this work was to investigate the thickness of bone and cortical bone in the region of maxillary posterior buccal at different angles from different heights of class?~1 and ?~2skeletal pattern patients by using cone beam computed tomography(CBCT),for better selection of adequate bone regions for the insertion of orthodontic mini-implants in?skeletal pattern patients.Methods:The study was carried out on the CBCT scans from 2 group of adult patients(n?=15 in each group)in the Department of Orthodontics of Shanxi Medical University School and Hospital of Stomatology.The first group involved skeletal class?~1 and the second group involved skeletal class?~2.In all,regions in the first molar and second premolar at different angles from different heights were evaluated.Buccal cortical bone thickness and bone thickness were measured in each region.The dates were analyzed statistically by using software of SPSS22.0.The variance analysis of the cortical and bone thickness at different heights and angles was performed.Independent sample t test was used to compare patients with class class?~1 and ?~2skeletal pattern patients.The LSD-t test was used to compare the two groups.The bone thickness clustering of micro-planting nails at different heights and at different angles was used.The situation uses K cluster analysis.The test levelawas 0.05.Results:(1)There were differences in the measurement of cortical thickness and bone thickness in adults with class?~1 and ?~2skeletal pattern,but the difference was not statistically significant.(2)There was a statistical difference(P<0.05)in the thickness of cortical bone of adult type?~1 and ?~2skeletal pattern patients implanted with micro-planting nails at different heights at the same height(P<0.05).The same height was implanted at 45°angle with the highest thickness of the cortical bone,at 90°the minimum thickness of the cortical bone,and the thickness at 60°of the cortical bone was between 45°and 90°.(3)There was a statistical difference(P<0.05)in different points with the same angle when the adult with class?~1 and ?~2skeletal pattern were implanted with micro-planting nails.The higher the position to insert the miniscrew implant,the thicker cortical thickness would be(4mm<6mm<8mm).(4)There were differences in bone thickness of micro-planting nails implanted at different angles at different angles,but the difference was not statistically significant(P>0.05).Conclusions:1.The greater the inclination angle of the implanted micro-planting nail at the same height,the larger the cortical bone.2.The cortical bone near the alveolar crest is thinner,and the thicker the cortical bone away from the alveolar crest.3.When implanting micro-planting nails clinically,it is necessary to adjust the location and angle of the implant with the height of the maxillary sinus floor.