Condylar Movement in Relation to Hellman's Dental Age of Eruption

本研究的目的是确定颞下颌关节髁突组件的路径与牙齿萌出的不同阶段。应用计算机辅助诊断轴测仪（CADIAX）对20例Hellman牙龄Ⅱ A、Ⅱ C、Ⅲ A、Ⅲ C期患者的髁状突活动轨迹进行分析。结果如下：1.在每个阶段，髁状突通道在所有记录的运动中都呈凹形.在II A期，最大平移值（sMax）在撑开-复位、侧向挤压和开合时分别为9.8 mm、11.5 mm和13.0 mm，与其他阶段相比，II A期的最大平移值显著高于其他阶段. II A期的最大旋转（γ最大值）为38.1 °，II C期为35.0 °，III A期为33.2 °，III C期为31.1 °。对于水平髁倾斜度为5 mm的前屈-后屈运动，分析值为II A期为37.3 °，II C期为41.6 °，II A期为46.6 °，III C期为46.3 °。发现阶段II A显著低于其他阶段。5.Ⅱ A期髁状突平移运动幅度较小，S期髁状突旋转运动幅度较大.在髁状突旋转与平移的关系中，Ⅱ A和Ⅱ C期在开放初期以旋转运动为主，Ⅲ A和Ⅲ C期以平移运动为主，开放后期各期均以旋转运动为主.观察到髁状突在打开和关闭期间的平移和旋转运动的差异。

The purpose of this study was to determine the pathways of the condylar-components of the temporo-mandibular joint in relation to the different stages of tooth eruption. The condylar pathways during protrusion-retrusion, lateral excursion, opening-closing of Hellman's Dental Age stage II A,II C,III A and III C were analyzed using computer-aided diagnostic axiograph (CADIAX) from a total of 20 subjects. The results were as follows :1. At each stage, the condylar pathway appeared concave at all recorded movements.2. At Stage II A,the maximum translation value (sMax) during protrusion-retrusion was 9.8 mm, lateral extrusion was 11.5 mm and opening-closing was 13.0 mm. In comparison to the other stages, the maximum translation value of Stage II A was found to be significantly higher than the other stages.3. The values of maximum rotation (gamma max) for Stage II A was 38.1ﾟ, StageII C was 35.0ﾟ, Stage III A was 33.2ﾟand Stage III C was 31.1ﾟ.4. For the protrusion-retrusion movements with a Horizontal Condylar Inclination of 5 mm, the analyzed values for Stage II A was 37.3ﾟ, Stage II C was 41.6ﾟ, Stage II A was 46.6ﾟand Stage III C was 46.3ﾟ. Stage II A was found to be significantly lower than the other stages.5. The magnitude of translation of the condylar movement of Stage II A was small, Sowever, a bigger magnitude of rotation was observed.6. In the relationship between condylar rotation and translation during opening, a predominant appearance of rotation movement in initial stage were observed for Stages II A and II C ; and translation movement for Stages III A and III C.During the final stage of opening movement, the predominance of rotation movements was observed in all stages.7. A difference in the translation and rotation movements of the condyle during opening and closing were observed.