臺灣博碩士論文加值系統

本研究目的是要觀察閉口肌之大小及走向和顱顏形態對咬力施出之影響。
實驗對象為有完整齒列，咬合良好，無顎關節障礙之男性27位。受測者接
受側面測顱X光攝影及測顱分析術以分析其顱顏形態；另外利用磁共振攝
影術（MRI）獲取顱顏部之軸向面及額向面影像，由電腦軟體計算出咬肌
及內翼肌最大橫切面面積及體積。顴點間寬距及角點間寬距也從MRI之額
向面影像中測取。咬力測量則是利用壓電轉換器置於慣用側之第一大臼齒
區去記錄其瞬間最大咬力之施出；受測者施出其最大咬力的同時，一併利
用EMG測量咬肌單位時間內平均之肌電值。
由實驗得知最大咬力平均為83.50±21.50公斤，咬力施出時咬肌之肌電值
為124.15±51.23毫伏／每秒。咬肌及內翼肌最大橫切面面積平均依次
為6.22±0.87平方公分、3.38±0.47平方公分。而咬肌及內翼肌體積平均
分別為31.38±6.50立方公分及10.93±2.09立方公分。咬肌之走向較內翼
肌垂直。利用逐步排除法之迴歸分析（Stepwise regression analysis）
來觀察肌骨骼組合對咬力施出之影響，結果顯示高達86% 之咬力施出受包
括咬肌及內翼肌之體積及走向，咬肌肌電值，臉部之前後徑大小等因素之
組合影響（r?0.86 , p<0.0001）。所以咬力之施出應是受多因素組合之
? A非由任何單一之因素就可代表或預測其表現。

The purpose of this study was to observe effects of the size
and orientation of the jaw closing muscles and the craniofacial
morphology on the exertion of biting force. Twenty-seven
pterygoid muscles. A system was developed for such measurement
. The orientation of the muscles was also derived. Maximal bite
force and EMG activity of the masseter muscle were obt
espectively. The volume of the masseter muscles was 31.38 ±6.50
cm3 and that of medial pterygoid was 10.93±2.09 cm3. The
masseter muscle was located more vertically than the medial
ffect the bite force performance ( R2= 0.86, p<0.0001 ). It was
concluded that the bite force performance is determined by a
combination of many factors rather than by any single fa