联合动态MRI和下颌运动轨迹描记仪分析健康人开闭口时下颌运动轨迹特征

目的：结合动态MRl分析健康人开闭口时下颌运动轨迹特征。方法：18例健康人最大开闭口过程进行动态MRI和下颌运动轨迹描记仪检查,分析髁状突及下颌前牙切点的运动特点及范围。结果：动态MRI显示闭口位关节盘本体部呈双凹形,本体部位于髁状突横嵴的前方（盘分界角〈10。）。健康人下颁前牙切点运动轨迹平滑,双侧运动中心运动轨迹左右对称;运动轴始终保持平行,呈现开闭口初、末时密度比开闭口中时大;运动中心运动距离（13．2±3．1）mm,切点运动距离（41．1±3．8）mm。结论：下颌运动轨迹描记能记录髁状突运动轨迹并且间接反映颞下颌关节的关节盘在开闭口运动中的位置变化情况,为初步建立下颌运动轨迹描记对辅助诊断关节病的参考标准奠定了基础。

Combining Pseudo-dynamic MRI and Mandibular Movement Tracing to Analyze the Characteristics of Open-close Jaw Movement of Healthy Subjects

Objective： Applying pseudo--dynamic MRI and mandibular movement tracing to investigate the tracking of mandibular condylar and incisor movement. Methods： MIRs were obtained from 18 healthy individuals and the jaw tracking and movement range of maximal opening and closing were studied. Results： Pseudo--dynamic MRI showed a significant double--concave disc in closed position and the disk in front of condylar ridge （plate boundaries angle 〈10°）. The jaw tracking of opening and closing were smooth and superposition. The density of kinematic axis had significant difference between the initial and end stage and intermediate stage about opening movement, but it always kept parallel. The range of opening movement and maximal value of condylar movement and incisor move ment respectively were 13.2±3. lmm and 41.1±3.8mm. Conclusion： The jaw tracking analysis with ARCUSdig ma System reflects the TMJ disc in the opening and closing movement, and is useful for temporomandibular internal disorders diagnosis in clinic.