A Radiological Study on the Bone Structures in the Functional Temporomandibular Joint

对颞下颌关节（TMJs） x线片异常的评估取决于其骨结构形式的主体间和主体内差异。本放射学研究的目的是通过颞下颌关节紊乱（TMD）患者的选择性侧位断层扫描，明确颞下颌关节对习惯性下颌运动的适应性骨变化，估计其刚过生长期后髁突头侧面的基本形态，探讨颞下颌关节结构变化的过程，并分析患者咀嚼周期。实验结果如下：(1)作为常规tmj影像学检查，选择性侧位断层扫描发现TMD患者的髁头后关节面异常变平或凹陷。(2)有159例患者出现髁突头凹，发生率约30%，甚至在30岁以上年龄组。结果表明，这种凹陷不仅是一种衰老，而且可能是TMD患者的一种适应性变化。(3)提出了一种同时多层层析成像叠加技术，用于颞下颌关节的x线测量。在后续研究中，该技术证明了髁头形状的变化与下颌骨的空间变化是相互作用的。也就是说，髁突头的前上复位导致髁突缩短。(4)将刚过生长期的患者髁头外侧侧面分为6组。第一个明显小而圆的组和第二个细长的组被认为是发育异常，因为下颌运动在其生长期对TMJs施加了功能负荷。(5) TMD患者咀嚼周期分析不能反映髁突头的适应性变化与颌骨运动的关系。功能载荷对颌部运动的影响有待进一步研究。少

An evaluation of abnormalities on radiograms of the temporomandibular joints (TMJs) depends on the inter-and intrasubjects differences in form of their bone structures. The aim of this radiologic study is to clarify the adaptive bone changes of the TMJs to habitual jaw movements, estimating the basic forms of the lateral aspects of the condylar heads just after the growth period of them and investigating a process of structural changes of the TMJs on the selective lateral tomograpms of the patients with temporomandibular joint disorders (TMD), and analyzing chewing cycles of the patients recorded by a Sirognatho Analyzing System II. The resutls were as follows ;(1) Flattening or a concavity was unexpectedly found on the posterior articular surface of the condylar heads of the patients with TMD by the selective lateral tomography as a routine radiographic examination of the TMJs.(2) With an incidence of about 30%, the concavity was found on the condylar head of 159 patients, even in eve … More ry age group on a radiological study. The result indicated that the concavity was not merely a aging, but probably an adaptive change in the patient with TMD.(3) A superimposing technique of simultaneous multisection tomograms was developed for the radiographic measurement of the TMJs. On a follow-up study, the technique proved that the change in shape of the condylar head and the spatial change of the mandible were interacted with each other. That is, antero-superior repositioning of the condylar head lead the condyle into the shortening.(4) Lateral aspects of the condylar head of the patients just after the growth period were classified into 6 groups. The first, significantly small and rounded group and the second, elongated group were considered to be a developmental anomaly due to the functional loading to the TMJs during jaw movements on their growth period.(5) Analysis of chewing cycles of TMD patients could not manifest the relationships between the adaptive changes of the condylar head and jaw movements. Further studies on jaw movements were required for the functional loading. Less