CLINICAL APPLICATION OF MICRO -SCREW IMPLANT ANCHORAGE IN TREATMENT OF ANGLE'S CLASS II DIVISION 1 MALOCCLUSION WITH DEEP OVERBURDEN JAWS / 现代医院

ABSTRACT

Objective To assess theapplication values of self -tapping micro-screw implant anchorage in treatment of Angle's class II division 1 malocclusion with deep overburden jaws , compared with the traditional anchor-age.Micro-screw implantswere inserted in maxillary teeth of patients with Angle's class II division 1 malocclusion with deep overburden jaws tostrengthen anchorage .Changesin position of the maxillary incisor and the first molar were compared.Methods 68 cases of Angle's class II division 1 malocclusion with deep overburden jaws were selected and randomly divided into the research group and the control group .The research group wastreated with a self -tap-ping micro-screw implant as ananchorage .The control group was treated with Nance bow , transpalatal arch or in combination with face bow as strong anchorage .The total treatment time , line spacing and the angle differences be-tween the U1/SN of X-ray cephalometry before and after treatment were compared in two groups .Results ①The-self-tapping micro-screw implant kept stability without looseness .Thesoft tissue surrounding dental implants had no swellings or infections .Patients had no obvious discomfort .②The average periods of treatmentin the research group and the control group treatment were 20 months and 26 months, respectively.③The soft -tissue profilein the re-search group was improved significantly , with 4.26 mm and 4.54 mmof the adductions ofthe upper and lower lips rel-ative to aesthetic plane respectively .The angle of U1/SN was reduced 10.2°.Theadductionsof the upper and lower lipsin the control group relative to aesthetic plane were 2.88 mm and 3.01 mm respectively and there werestatistically significantdifferencesin two groups .There were no remarkableanteroposterior and verticalmovement after correction of maxillary first molars(p>0.05)but the anteroposterior incisor movement in the research group .The movements were statistically significant differences(p<0.01).Conclusion Compared with the traditional anchorage technique , mi-cro-screw implant anchorage can better control teeth movement and shorten the treatment time .