Showing papers by "Major M. Ash published in 1980"
TL;DR: In eighteen subjects assigned for immediate complete upper and lower dentures, roentgen cephalometric recordings were made before extraction of the residual anterior dentition and 3 weeks, 3 months, 6 months and 1 year after denture insertion.
Abstract: In eighteen subjects assigned for immediate complete upper and lower dentures, roentgen cephalometric recordings were made before extraction of the residual anterior dentition and 3 weeks, 3 months, 6 months and 1 year after denture insertion. The cephalometric analysis was based on electronic measurements of linear and angular morphological variables and computer head plots generated from 177 reference points (Walker, 1967), derived for each subject for each of the five observation stages. The reduction of the alveolar ridges was most rapid during the first 3 months of denture wear and particularly during the post-extraction period of 3 weeks. The reduction in anterior height of the lower ridge was on average twice as great as that of the upper ridge. The ridge resorption and the accompanying settling of the dentures on the basal seats, measured from lead shots inserted in the dentures, brought about an upward rotation of the mandible with a resulting decrease in occlusal vertical dimension and reduction in overjet of the dentures. In accordance with the amount of ridge reduction, these changes showed great individual variation.
98 citations
TL;DR: EMG study of subjects wearing immediate complete upper and lower dentures revealed marked alterations in activity of the jaw closing muscles during the biting actions recorded, which suggests that changes in jaw and occlusal relationships due to resorption of residual ridges and settling of the dentures also affects jaw muscle activity.
Abstract: EMG study of subjects wearing immediate complete upper and lower dentures revealed marked alterations in activity of the jaw closing muscles during the biting actions recorded. This finding suggests that changes in jaw and occlusal relationships due to resorption of residual ridges and settling of the dentures also affects jaw muscle activity. The relations between EMG and morphologic findings will be analyzed further in a separate article.
42 citations
TL;DR: A small, economical, and accurate system for measuring the silent period duration as well as the latency has been designed and it is concluded that this measuring system is suitable for clinical use.
Abstract: A small, economical, and accurate system for measuring the silent period duration as well as the latency has been designed. In nine normal subjects electromyographic silent periods in the masseter muscle were measured both manually and by the system. With the comparison of those data, it is concluded that this measuring system is suitable for clinical use.
6 citations