THE STUDY OF A JAW MOVEMENT BEFORE AND AFTER TOTAL TMJ REPLACEMENT

人体的所有关节都受到衰老和某些疾病的影响。它们会导致形态学和功能性的萎缩。人工关节置换术恢复了这些塌陷的关节。然而，在日本，颞下颌关节的人工关节还没有发展起来，所以我们没有任何有效的治疗TM关节疾病的严重失调。在本研究中，我们基于对人类下颌骨的形态分析和下颌运动的动力学因素，提出了最新的Sugahara人工TM关节，它提供了在日常生活中有效的工作能力。我们展示了其在口腔颌面领域的临床应用。为了创新人工TM关节，我们通过重建3D-CT图像对尸体和人体骨骼模型上的TM关节进行解剖测量。在测量下颌头和关节盂窝表面形态的基础上，运用赫兹理论和三维有限元方法对咀嚼过程中载荷的变化进行了分析。这些结果促成了Sugahara人工TM关节首次用于人体的试验。我们对慢性类风湿关节炎引起的闭塞困难和阻塞性睡眠呼吸暂停患者进行了全TM关节置换技术。通过咀嚼咬合功能检查、超声影像学检查、x线影像学检查和下颌运动测量评估TM关节运动。结果表明，在下颌运动中，观察到以人工TM关节为中心的铰链轴运动。未发现侧移和滑动运动。根据肌电图评价，术前颞肌和乳突肌的活动均较正常肌弱。手术后，这些肌肉的活动变弱了。手术后需要几个月的时间练习张嘴，以适应手术中给出的咬合位置。作为下颌的前置换术，上呼吸道的距离很可能有利于呼吸。病人的呼吸障碍得到缓解，说话能力也有所改善。并对人工TM关节形态的改进进行了展望。这有望引领TM关节的高功能和更安全水平。此外，在人工TM关节创新的过程中，我们的新技术包括重建的3D-CT图像、接触式和非接触式精确的三维测量和评估系统、评估的叠加法、曲面的定量评估等，可以实现对涉及上颌骨、面骨、板的口腔颌面结构发育过程和生长方向的微观测量。本研究对口腔颌面学的其他领域研究有一定的促进作用。在1997年第八届国际腭裂及相关颅面畸形年会上，我们获得了Owen Cole奖。少

All joints of human body are affected by aging and some disease. They cause the morphologic and functional atrophy. The technique of artificial joint replacement has restored these collapse joints. In Japan, however, the artificial joint for the temporomandibular joint has not been developed before so that we did not have any effective treatment for the TM joints disease with the severe disorder. In this study, we presented the newest Sugahara artificial TM joints, which provides the effective ability to work in the daily life, based on the morphological analysis of human mandibular head and the dynamical factors in the jaw movement. We demonstrated the clinical application in the oral and maxillofacial field.In order to innovate artificial TM joints, we measured anatomically the TM joints taken from cadavers and human skeleton models by the reconstructive 3D-CT images. Based on the measement of the surface form of the mandibular head and the glenoid fossa, the load occurring in the pr … More ocess of chewing was analyzed by Hertz theory and the 3-dimensional finite element method. These results contributed to the first trial of Sugahara artificial TM joint for the human body.We performed this total TM joint replacement technique for the patients who have difficulty in occlusion and obstructive sleep apnea caused by chronic rheumatoid arthritis. These patients were assessed by the occlusal functional examination for chewing and the ultrasonic imaging examination, radiographic examination and measurement of jaw movement for the evaluation of TM joint movement.As a results, in the jaw movement, hinge axis movement was observed with the center of artificial TM joint. And the lateral and gliding movement were not found.According to the evaluation by the electromyogram, the activity of the both temporal and mastoid muscles got weak compared with normal one before the operation. After the operation, the activity of these muscles became weaker. It was seemed that the several months to exercise an opening mouth after the operation would be required to adapt the occlusal position given in this operation.As the anterior replacement of the jaw, the distance of the upper airway was likely to be well to breath. The patient was relived from the respiratory disturbance and also improved in speaking.As our furthermore prospect, the improvement of the form of the artificial TM joint will be discussed. This is expected to lead the high function and safer level of TM joints.Additionally, in the proces of the artificial TM joint innovatin, our new technology involving the reconstructed 3D-CT image, the contact and non-contact type-accurate 3-dimentional measuring and evaluating system, the superimposing method for evaluation, and the quantative evaluation of curved surface could realize the micro-measurement of the development process and the growth direction of the oral and maxilloafacial structure involving the maxilla, facial skelton, and plate. This study contributed to the other field research relating to oral and maxilofacial field. We were awarded the Owen Cole prize in the 8th annual meeting International Congress on Cleft Palate and Related Craniofacial Anomalies in 1997. Less