Study Of Condyle Movement Traceings In Angle â…¡~2 Malocclusion Pretreatment And Post-Treatment

AngleⅡ2 malocclusion is common.The incidence is about 5%～18%,the characteristic dental appearances are:the molar relationship is distal,the upper incisors are lingual inclination,and the overbite is very deep while the overjet is small.This malocclusion has severe effects on stomatognathic system such as health, aesthetics, function and the growth of the maxillofacial region,meanwhile it has close correlated with the TMD.The relationships between AngleⅡ2 malocclusion and the therapy as well as TMD are one of the most focuses in orthodontic filed.Our research is to study the condyle movement tracings in AngleⅡ2 malocclusion pretreatment and post-treatment, so as to know the kinesis of the TMJ and to observe the Schüller position of the TMJ in both sides.From this researth we could summarize the dynamic and static diversity in AngleⅡ2 malocclusion in order to provide some references for clinical therapy.Sample was composed of control group (20 cases with individual normal occlusion), experiment group 1(19 AngleⅡ2 cases without TMD) and experiment group 2(18 AngleⅡ2 cases with one side of TMJ click).All the objects were taken the Schüller position to analyse the position of condyle in articular fossa and to compare with the control group.CADIAXⅢwere used to trace the condyle movement during mandibular open/close, protrusion/retrusion and lateral movement, and to make qualitative and quantitative analyses.The conclusions were as follows:1 Before treatment, the condylar position of 62.85% patients in expeniment 1 and 77.78% in expeniment 2 was retroposition. Because of the removal of the locked-bite after treatment, only 17.1% in expeniment 1 and 19.44% in expeniment 2 were still retroposition. Compared to the pretreatment, the condylar position of 45.7% patients in expeniment 1 and 58.33% in expeniment 2 recovered from retroposition to mesoposition.It was inferred that orthodontic treatment make the disc-condyle relationship return to normalization.2 The condyle tracings of AngleⅡ2 malocclusion presented conspicuous verticality, and AngleⅡ2 patients with one side of TMJ click existed individuality:The tracings were asymmetry, lack of coincidence, and irregular fluctuation while the click happened. After treatment we could see the obvious improvements.3 All the index changed remarkably after treatment in AngleⅡ2 malocclusion.It was suggested that orthodontic treatment make the occlusion, muscle and TMJ of patients reach a new balance, thereby the condylar movement became much more coherent.