Studies on Masticatory Force and Electromyogram in Full Overdentures

Cases of Bilateral Mandibular Canines Using for Anchor Teeth

Abstract

Observing the effect of the anchor teeth on the masticatory function in full overdenture used “O'ring” stud attachment on bilateral mandibular canines, the author studied with the masticatory force and electromyogram at the same time. As the results of these studies, the author arrived at the following conclusions.
1. The masticatory forces were largest on the pickled radish. In foods, the largest masticatory forces were measured in 3rd period and the smallest in 5th. The antagonistic forces were smaller. The significant F factors were found for the food, the masticatory period, the interaction of them and the interaction between the side and the masticatory period.
2. According to the rhythm of masticatory force and swallowing pattern, the duration (D), the interval (I), and the term (T) were largest on the peanut. In foods, the largest rhythms were measured in 1st period and the smallest in 4th. The swallowing pattern was larger. Further, the ratio of the duration to the term (D/T) were largest on the peanut. The significant F factors were found for the food, the side, the masticatory period and the interaction of them.
3. As for the rhythm of electric discharge of masticatory muscles, the D, the I and the T were largest on the peanut. In foods, the largest rhythms were on 1st period and the smallest in 4th. The swallowing pattern was larger. However, the D/T showed the same values in mastication. The swallowing value was smaller. The significant F factors were found for the food, the side, the masticatory period and the interaction of them.
4. The integrated amounts of masticatory forces were largest on the ham. In foods, the largest values were measured in early period and the smallest in late. The significant F factors were found for the food, the side, the masticatory period and the interaction of them, but except the side and the interaction between the side and the masticatory period.
5. In terms of the integrated amounts of muscular activity, the largest values were on the ham. In foods, the largest values were measured in 3rd period and the smallest in 5th. The swallowing was larger. The significant F factors were found for the food, the side, the masticatory period and the interaction of them.
6. The integrated amounts of muscular activity required per unit of the integrated amounts of the masticatory forces were largest on the pickled radish. In foods, it's values were larger in early period and smaller in late. The swallowing was larger. The significant F factors were found for the food, the masticatory period and the interaction of them.
7. In numbers of masticatory stroke, the peanut were most. However, the significant F factor was not found for the food.
From these studies, it was given a suggestion that the full overdenture wearers masticate more efficiently and harmoniously than the full denture. It was estimated that the reasons were the rich sensation from the mechanoreceptor in periodontal ligament, the remaing the alveolar ridge and the improvement of denture stability and retention from the attachment.