Class III不正咬合者の咀嚼運動 : 正常咬合者とClass III不正咬合者の咀嚼運動の比較

概要

論文の詳細を見る
o examine the cooperation between EMG activities of the masticatory muscles and mandibular movement, the mandibular movements and the EMG activity of the masseter and temporalis muscles were simultaneously recorded by Gnathohexagraph during chewing a gum in 40 adult subjects. They consisted of 20 Class I and 20 Class III subjects. The timings for the onset, peak, and offset of EMG activity during chewing a gum were estimated relative to the maximum opening and occlusal terminal points in the traces of incisor point. The timings of EMG activity and the maximum opening and occlusal terminal positions were compared between two groups. The following results were obtained : (1) The maximum mouth opening position shifted to the working side in Class III subjects as compared with Class I subjects. (2) The occlusal terminal position shifted to the balancing side in Class III subjects. (3) The ratio of closing phase to a chewing cycle was significantly greater in Class III subjects than in Class I subjects. (4) Duration of EMG activity was longer in Class III subjects than in Class I subjects due to the extended offset time of EMG activity. These results suggest that the size and position of the mandible and the inter-occlusal relationship could influence the masticatory movement.
九州歯科学会の論文
2003-10-25