Study on the relationship between the head movements and the body movement during rhythmical jaw movements

本研究的目的是从站立和坐位的身体运动角度来评估口腔功能与全身状况的关系。我们设计并开发了一种新的六自由度跟踪装置（TRIMET□），并将其用于头部和下颌运动的三维注册。还使用放置在天花板上的两个动作捕捉装置（ProReflex）来测量身体运动。此外，我们建立了一个新的系统来同时分析这三种数据在同一时间轴上。下颌运动时，下切点记录在上颌骨参考系上。对于头部运动，将上切点、顶骨点、枕骨点和髁突点记录在地面参考框架上。同时，记录胸骨点的运动，并在地面参考系上进行分析。研究对象为男性6例，口颌功能正常，年龄25 ~ 29岁，平均年龄27岁。在坐位上，开口时观察到头部伸展，闭口时观察到头部弯曲。与这些头部运动同步，身体在张嘴时向前移动，在闭口时向后移动。在站立时，头部和身体的运动也与下颌运动有相同的节奏。站立位的身体运动也与下颌运动同步，观察到前后前后漂移的大振幅中有小振幅的前后漂移，这似乎是呼吸的影响。另一方面，呼吸的影响没有观察到的座位位置。站立和坐位时，前后体运动距离与下颌运动同步，随开口范围的增加而增加。然而，在不同的被试中，绝对值是不同的。站立位和坐位的身体运动与开口范围的平均比值分别为2.3 ~ 6.1%和2.0 ~ 4.8%。站姿与坐位的比值从0.2 ~ 1.3%增加。少

The aim of this study was to evaluate the relationship between the stomatognathic function and the systemic condition from a viewpoint of body movements in the standing and seating positions. We designed and developed a new six-degree-of-freedom tracking device (TRIMET□), and used it for the three-dimensional registration of head and mandibular movements. Body movements were also measured using two motion capture devices (ProReflex), placed in the ceiling. Furthermore, we built a new system to analyze simultaneously these three kinds of data on the same time-axis. For mandibular movement, the lower incisal point was recorded on the maxilla reference frame. For head movement, the upper incisal point, the parietal point, the occtipital point, and the condylar points were recorded on the ground reference frame. Simultaneously, the motion of the sternum point was recorded and analyzed on the ground reference frame. The subjects were 6 males with normal stomatognathic functions, aged 25〜29 … More years, with a mean age of 27 years.On the seating position, the head extension was observed during mouth opening and the head flexion was observed during mouth closure. Synchronizing with these head movements, the body moved anteriorly with mouth opening and moved posteriorly with mouth closure. On the standing position, similar head movements and body motions were also observed in the same rhythm with mandibular movements.The body movement in the standing position was also synchronized with the mandibular movement, and was observed as antero-posterior drifts of small amplitude within the large amplitude of antero-posterior drifts, which seemed to be the effects of breathing. On the other hand, the effects of breathing were not observed in the seating position. The distance of antero-posterior body movements, synchronized with mandibular movement, showed a tendency to increase with the increment of range of mouth opening, both in the standing and seating positions. However, the absolute values were differed among the subjects. The average ratio of the body movements to the range of mouth opening was 2.3〜6.1% in the standing position and 2.0〜4.8% in the seating position. The ratio was increased from 0.2〜1.3% in the standing position in comparison with the seating position. Less