Kohno S, Matsuyama T, Medina R U, Arai Y
Department of Removable Prosthodontics, Niigata University, School of Dentistry, Niigata City, Japan.
J Oral Rehabil. 2001 Feb;28(2):161-7. doi: 10.1046/j.1365-2842.2001.00636.x.
It is known that small head movements accompany the movements of the jaw during mastication; however, it is unknown whether these movements occur rhythmically and synchronously. The objective of this study was to determine whether there exists a functional coupling between the head and mandibular movements. Four healthy male adults (mean age 25.5) with normal occlusion and without TMD history were selected as subjects. Using the Trimet system, we measured tridimensionally both the movement of the head and the mandible by tracking upper and lower incisal points, respectively, during tapping movements with different opening range and frequency, then analysed the vertical component of these movements. The upper incisal point moved in opposite direction to the mandible in all tapping strokes in all subjects, during opening the head moved in a cranial direction and during closing in a caudal direction; the incidence rate for this concomitant movement was 98%, implying that the head moves periodically and rhythmically, as the mandible does. The cycle time of these coincident movements showed a correlation coefficient of 0.94. Moreover, the vertical range of head movement was within 10% of the jaw's movement. From these results we concluded that, at least during teeth tapping, the head moves in rhythmical coordination with mandibular movement.
众所周知，咀嚼过程中头部会伴随下颌运动产生小幅运动；然而，这些运动是否有节奏且同步尚不清楚。本研究的目的是确定头部与下颌运动之间是否存在功能耦合。选取了4名咬合正常且无颞下颌关节紊乱病史的健康成年男性（平均年龄25.5岁）作为研究对象。使用Trimet系统，在不同开口范围和频率的叩击运动过程中，分别通过追踪上下切牙点，三维测量头部和下颌的运动，然后分析这些运动的垂直分量。在所有受试者的所有叩击冲程中，上切牙点的运动方向与下颌相反，开口时头部向颅侧移动，闭口时向尾侧移动；这种伴随运动的发生率为98%，这意味着头部与下颌一样，会周期性且有节奏地运动。这些同步运动的周期时间显示相关系数为0.94。此外，头部垂直运动范围在颌骨运动范围的10%以内。从这些结果我们得出结论，至少在叩牙过程中，头部与下颌运动有节奏地协调运动。
