The Correlative Study Of Condyle Rotation Angle And Curative Effects Of Occlusal Reconstruction By Different Therapeutic Regimens

Objectives:To discuss the possibility of using the condyle rotation angle as a inclusion criteria to choose different treatment plans by analyzing the dependability of condyle rotation angles and disorders of craniomandibular index(CMI),electric activities of TA and MM pretherapy and post-treatment.Methods:18 patients were chosen with dentition defects and decreased vertical dimension which was caused by severe dental attrition.The patients were divided into two groups named group A and group B randomly,and each group owned 9 patients respectively.Patients in group A got treatment perscription including a transitional therapy before the permanent therapy,and group B got only a permanent therapy.Every patient was got shots of skull lateral projections before and after therapies and the condyle rotation angles could be measured.Each patient was also got examinations of CMI and myoelectricity changes of TA and MM before and after therapies.Finally the datas were made statistics analyzing.Results:At the demarcation points of 3°,group A and group B could be divided into two groups respectively which were named A1(condyle rotation angles＜3°),A2,B1(condyle rotation angles＜3°) and B2.The regularities of the datas were as following:1.Craniomandibular index(CMI):In group A1,A2 and B1,the CMI population means were reduced with statistical significance.There was no statistical significance of CMI population means of group B2 before and after therapy. 2.Myoelectricity at quiescent conditions:After therapy,the myoelectricities of TA and MM of group A1,A2 and B1 were diminished,and the differences possessed statistical significance.There was no statistical significance of TA and MM myoelectricities of group B2 before and after therapy.3.Myoelectricity at tight bite conditions:After therapy,the myoelectricities of TA and MM of group A1,A2 and B1 were enhanced,and the differences possessed statistical significance.There was no statistical significance of MM myoelectricities of group B2 before and after therapy.4.Dissymmetry index at tight bite conditions:After therapy,the datas of AsTA,AsMM and Astot of group A1,A2 and B1 were all smaller than before,and the differences possessed statistical significance.There was no statistical significance of the datas of AsTA,AsMM and Astot of group B2 before and after therapy.Conclusions:1.Reasonable occlusal reconstruction therapies can relieve symptoms of disorders of temporomandibular joint,remittence the tensity of muscles of mastication at quiescent conditions,elevate the contractibility and symmetry of muscles of mastication at tight bite conditions and then recover patients' masticatory function.2.There are correlations of condyle rotation angles and different curative effects of occlusal reconstruction by different therapeutic regimens.3.A transitional therapy before the permanent therapy is necessary when the condyle rotation angle exceeds 3°.