Diagnostic Application of Functional Coupling between Jaw Function and Balanced Head Movement

我们以前已经证明了存在的功能耦合之间的头部和下颌骨。本研究通过对正常人和颞下颌关节紊乱病患者的头、下颌运动和咀嚼肌、头颈肌肌电活动的三维测量，探讨了颞下颌关节紊乱病患者头、下颌运动和咀嚼肌、头颈肌肌电活动的变化规律，揭示了颞下颌关节紊乱病患者头、下颌运动和咀嚼肌、头颈肌肌电活动的三维变化规律，并探讨了颞下颌关节紊乱病患者头、下颌运动和咀嚼肌、头颈肌肌电活动的三维变化规律。头部在相同的周期时间内周期性地移动，咀嚼和牙齿轻叩下颌运动。头部呈旋转样矢状运动，旋转中心位于颅底点上方。咀嚼肌和颈肌（胸锁乳突肌）表现出与下颌运动同步的节律性活动。颈部肌肉活动度与咀嚼力呈直线相关。此外，颈部肌肉似乎在下颌运动的咬合阶段之前就开始活动了。结果表明，颈部肌肉的贡献同步头部运动的预期方式。颞下颌关节紊乱病患者在咀嚼和叩齿过程中，头与颌运动的同步程度约为健康人的四分之三。该变量受TMD症状的影响，特别是下颌开口受限，这表明头和下颌运动之间的耦合的机械特征。在我们的研究中，咬合特征对头部运动的贡献还没有得到证实。

We have previously demonstrated the existence of a functional-coupling between the head and the mandible. The objective of the present study was to reveal mechanisms of this functional coupling and effects of occlusion on this coupling.We measured tridimensionally both the movement of the head and mandible and the electromyographic activities in the masticatory and head-neck muscles in healthy subjects and patients of temporomandibular disorders.In healthy subjects, heads moved cyclically in the same cycle time as that of both masticatory and tooth-tapping jaw movements. The head underwent a rotation-like sagittal movement whose rotation center located above the cranial base point. The masticatory muscles and the neck muscle (the stemocleidmastoid muscle) showed rhythmical activities synchronized with jaw movements. The neck muscle activity showed a linear correlation with masticatory force. Additionally, it was seem that the neck muscle began the activity before the occlusal phase of jaw movements. It is demonstrated that the neck muscle contribute to the synchronized head movement in the anticipatory manner. However we could not confirm that this coordinated head movement would influenced on whole body flicking.In patients of temporomandibular disorders, the degree of synchronization between head and jaw movement was approximately three-quarters of that with healthy subjects during mastication and tooth-tapping. This variable was influenced by existence of TMD symptoms, especially limited jaw opening, which suggests mechanical feature of the coupling between head and jaw movement. Contribution of occlusal features to head movement has not been confirmed in our study.