单侧后牙反者髁突侧向运动轨迹的研究

The study of tracing of the condylar movements daring lateral excursion of the nnilateral posterior crossbite

目的通过记录单侧后牙反者与正常者下颌侧向运动时髁突在三雏方向上的运动轨迹。探讨单侧后牙反者髁交侧向运动轨迹的特征。揭示其与正常之间的差异。方法正常15例,单侧后牙反7例．应用计算机化的髁突运动轨迹描记仅(computer-Aide,Axiography,CADlAX)Ⅰ型以及分析软件(Gamma Dental Sofrware for Windows 2．3．2．22。GDSW)记录下颌做左右侧向运动时髁突在水平面及矢状面上的运动轨迹。结果实验组侧向运动中非工作侧矢状向最大位移量王著小于正常对照组。工作侧髁突向后运动的幅度大于正常对照组。结论单侧后牙反者髁突侧向运动轨迹形态与正常有明显差异。其两侧关节囊、韧带松驰。

Objective To evaluate if the dental occlusion can influence the mandidular lateral excursion. The characteristic tracings of mandibular movements at the condyle of unilateral posterior crossbite patient were investigated by using a computerized axiography. The differences between the patients with normal occlusion and the patients with unilateral posterior crossbite were compared using recorded condylar movements in three dimensions. Methods Seven patients with unilateral posterior croossbite patients （at least two posterior teeth were crossbite） were included as experimental group; fifteen subjects with normal occlusion without the signs or symptoms of temporomandibular disorders （TMD） were included as controls. Using Computer- Aided Axiography （CADIAX） and the gamma dental software for windows 2.3.2.22 （GDSW） from Grbh company（Germany）, the tracings of condylar movements in right and left parasagittal planes during lateral excursion were recorded. Data were transfered into the computer and analyzed using GDSW software. The drifts in X, Y,Z coordinate of condylar movements, the transverse condylar inclination from the orbital axis line, and the horizontal condylar inclination were calculated, respectively. Results The length of the axiographica mediotrusion movement of non- working side in sagittal direction showed significantly shorter in unilateral posterior croasbite than that in the control group. The posterior deviation of working side was larger than that in normal group. Conclusion The tracings of condylar lateral movements of experimental group are significantly different from that of control group. The articular capsula and ligament are loose in experimental group.