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

点击翻译按钮获取中文摘要

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