Muto T, Kanazawa M
Higashi-Nippon-Gakuen University School of Dentistry, First Department of Oral Surgery.
Oral Surg Oral Med Oral Pathol. 1994 May;77(5):451-5. doi: 10.1016/0030-4220(94)90222-4.
The positional change of the hyoid bone in both closed and maximal mouth-opening positions of the mandible was investigated by cephalometric measurements. The following results were obtained: (1) With the increase in mouth opening the hyoid bone moved downward and backward. At maximal mouth opening the head posture changed posteriorly compared with that of occluded mouth position. (2) By superimposing films of the S-N plane, it became apparent that the hyoid bone was displaced downward by sagittal opening movement of the mandible and backward by the posterior change of the head posture. (3) Significant correlations were found between the degrees of sagittal rotation of the mandible and the position of the hyoid bone. (4) These results suggest that the posterior change of the head posture and inferior shift of the hyoid bone with mouth opening are important factors in obtaining maximal mouth opening.
通过头影测量法研究了下颌骨在闭口和最大开口位时舌骨的位置变化。得到以下结果：(1) 随着开口度增加，舌骨向下、向后移动。与闭口位相比，最大开口位时头部姿势向后改变。(2) 通过叠加S-N平面的X线片，明显可见舌骨因下颌骨矢状向开口运动而向下移位，因头部姿势的向后改变而后移。(3) 发现下颌骨矢状向旋转程度与舌骨位置之间存在显著相关性。(4) 这些结果表明，开口时头部姿势的向后改变和舌骨的下移是获得最大开口度的重要因素。
