Maxillary Occlusal Plane Changes After Applying Micro-implant Anchorage Treatment To Maxillary Protrusion

Objective:To investigate changes of maxillary plane after applying micro-implant anchorage treatment to maxillary protrusion,as well as horizontal and vertical alterations of the maxillary anterior and posterior levels,and provide reference for clinic control of the occlusal plane when anterior and posterior teeth move.Methods:48 eligible cases selected from patients with maxillary protrusion attending Shenyang City Dental Hospital from 2014 to 2016.The patients were divided into experimental group and control group,each group of 24 cases,8 cases of experimental group were male,16 females,mean age 27.17 ± 5.10;control group 10 cases were male,14 were female,mean age 25.90 ± 6.07 years old.Orthotherapy was extracted the bilateral maxillary first premolar,experimental group using implant anchorage and sliding adduction of upper anterior teeth for space closure;the control group using the anchorage sliding adduction of upper anterior teeth for space closure.The statistical data was analyzed by the software of SPSS 17.0,the two groups of patients before and after treatment of cephalometric data of mean value and standard deviation were analyzed using paired t test,before and after the treatment of two kinds of treatment methods of the variation of relatively independent sample t test,P test standard<0.05 that the difference was statistically significant.Results:Two groups of patients after the end of treatment can obtain good occlusal relationship,but control movement,before and after the maxillary plane and mandibular plane angle difference.Maxillary plane(OP-SN)changes in the experimental group increased 3.2°,4.5° increased in the control group,P<0.01,highly significant difference.The mandibular plane angle(MP-SN)did not change significantly in the experimental group,and the control group increased by 1.9°,P<0.01,and the difference was highly significant.Overbite(OB)covering(OJ)change between the two groups was not obvious,P>0.05,no statistical significance.The maxillary central incisor to palatal plane vertical distance(U1-PP)in experimental group increased by 0.4mm the control group increased 1.7mm,P<0.01,the numerical difference between the two groups had significant changes in maxillary;apical to the RL line distance(U1R-RL)in experimental group decreased 1.5mm,the control group decreased 0.9mm,P<0.05 the differences between the two groups,significant changes to the data;level,to the RL line in the maxillary incisor distance(U1-RL)in experimental group decreased 6.8mm,the control group decreased 4.7mm,P<0.01,two groups of numerical difference.In the vertical direction,the maxillary first molar before and after treatment of the two groups have no significant difference;the horizontal,0.1mm distal movement in experimental group,the upper first molars in the control group,mesial movement 2.2mm,P<0.01,highly significant difference.Conclusion:1.Micro-implant can provide stable anchorage during the treatment of maxillary protrusion,and make full use of the extraction gap,so that the restoration of the anterior teeth is obvious and effective,and the loss of the posterior teeth resistance is avoided.2.Application of Micro Implant Anchorage of maxillary anterior teeth retraction of maxillary plane will rotate clockwise.3.Using of Micro Implant Anchorage in the treatment of maxillary protrusion with extraoral anchorage can reduce maxillary plane clockwise,better control of the vertical distance,avoid the clockwise rotation of the mandible.