バイラテラルバランスドオクルージョンとディスクルージョン

総義歯の咬合型式の相違による咀嚼筋筋電図に関する研究 第1報

抄録

In the complete denture prosthodontics, occlusal types of the artificial teeth arrangement are generally held to exert a large influence on the retention, stability and support of the prothesis, and there is a fairly abundant published literature dealing with occlusal balance of the complete denture to date.
From a current point of view, an occlusal type of complete denture at a-centric occlusal position always necessitates bilateral occlusal contacts. At an eccentric occlusal position, however, there is disagreement amongs investigators, some believe there is bilateral balanced occlusion, and some don't.
Since D'Amico and Stallard reported that the posterior teeth always are separated by the anterior teeth in function on the natural dentition, Stuart, Elkins and Kato advocated a Gnathological denture. This type of occlusion is called Mutually Protected Occlusion. However, there is the difference of the supporting structure between the artificial teeth and the natural dentition, the former is supported by oral soft tissues and the latter is supported by the periodontal membrane and alveolie. For this reason, it is said that the balanced occlusion on the complete denture has advantages for the denture wearers.
The purpose of this investigation was to compare with the difference in the occlusion between the bilateral balanced occlusion and the disclusion utilizing the electromyographic technique. One patient had maxillary and mandibular complete dentures, and other had a maxillary complete denture and mandibular metal splint. Full adjustable articulators (T.M.J, Hanau University 130-21) were used to make those prosthesis.
The results showed as follows: 1) The patient wearing both maxillary and mandibular dentures, showed a smaller amount of muscle activity at the bilateral masseters and tempolal muscles with the bilateral balanced occlusion than with the disclusion in function. 2) The patient having mandibular matural dentition, showed less muscle activity and it tended to be less with the disclusion than the bilateral balanced occlusion, especially the difference of the muscle activity per stroke was smaller. The above results indicate that the changes of occlusal types cause lesser influence upon the masticatory movement with the patient who wearing only maxillary denture than with the patient wearing both maxillary and mandibular dentures.