2002 年 1 巻 1 号 p. 31-40
Purpose : This study examined the functional efficacy of complete dentures with full balanced occlusion or lingualized occlusion in patients with different degrees of residual ridge resorption.
Materials and Methods : To compare the residual ridge condition among the five subjects, the alveolar ridge height and supporting area under the denture were measured. Experimental upper and lower complete dentures were fabricated with interchangeable molars and were used by the study subject for two months prior to the functional analyses. To estimate denture function, electromyography (EMG), mandibular kinesiography (MKG), and pressure distribution under the denture while tapping and masticating peanuts were investigated.
Results : The EMG results suggested that subjects with poor residual ridge condition may benefit from lingualized occlusion for more efficient mastication. The MKG results suggested that, in subjects with poor ridge condition, mastication tends to be unstable with a full balanced denture, but that widening of the mandibular path that destabilizes the denture is reduced with a lingualized denture. The results of pressure measurement suggested that when lingualized occlusion is provided for patients with a poor residual ridge condition, the occlusal pressure is transmitted mostly at the lingual side of the residual ridge, leading to efficient denture function.
Conclusion : A sufficient lingualized occlusion effect was obtained in subjects with a poor alveolar ridge condition. The following indexes were examined as the criteria for applying lingualized occlusion. The ratio of the residual alveolar ridge must be 0.5 or less, and the area of the supporting base of the denture must be 2, 000 mm2 or less.
