臺灣博碩士論文加值系統

本實驗之目的是於控制的咬力之下觀察咀嚼肌及胸鎖乳突肌在不同的下顎後縮前突位置之增員狀態。以20位顳顎關節炎女性病患為對象，臨床上在治療過一段時間後，出現前牙開咬，前牙垂直和水平重疊在治療中已顯現逐漸增大情形。對照組則為21位女性自願者。兩組之間在年齡、身高、體重等均相仿。
本實驗以全橋式串聯4個應變測計的音叉型咬力偵測器作為咬力測試，經校正後，以迴歸分析證實輸出電壓並不受施力點的影響（P＝0.9998）。
主體實驗方面，以雙極性表面電極貼於雙側前後顳肌、咬肌、胸鎖乳突肌，在中心咬合位置以及前牙牙尖對牙尖位置緊咬，求取咀嚼肌之最大收縮值。之後再以咬力計放入慣用側之第一大臼齒間，分別在中心咬位及2，4毫米之前突位置上（中心咬位表示為下顎最後縮之咬位）施以50，100或150牛頓之咬力，至少連續3秒鐘。每一咬位及力量之組合重覆測試五次，兩次測試間休息三分鐘。所有肌電訊號以均值平方根（root mean square）計算。
結果如下：病患組在中心咬合位置緊咬時的最大肌收縮值明顯低於對照組。靜態性咬力方面，利用廣義估計方程式處理肌收縮值與力量大小、受測者組別、年齡、身高、體重、與咬力器同側肌肉…等變數的迴歸模型中，發現咬力大小與肌收縮值有正相關（P＜0.05）。而前突咬位的改變對於對照組之肌收縮值有負相關（P＜0.05），但對病患組而言，則未達顯著差異。另外，此肌肉是否與咬力偵測器同側也與靜態性咬力表現有正相關。此外亦發現胸鎖乳突肌的增員情況，於緊咬時，與咬肌相似，但在單側咬力測試中，並未發現胸鎖乳突肌與其他的咀嚼肌有明顯共收縮的情形。
根據以上的發現，可知力量大小是影響肌收縮活性施出最重要的因素，而病患組在單側垂直咬力測試中，下顎位置的改變對於肌肉的增員，並未達顯著差異。

The purpose of this study was to examine the recruitment of masticatory muscles and sternocleidomastoid muscle at different protrusive-retrusive jaw positions under the control of biting forces. Twenty female patients of TMJ arthritis whose overjet and overbite of anterior teeth had found to be changed during the course of treatment were included in this study. Twenty-one normal subjects with similar age, height and weight were selected as control group.
A fork-type force transducer was constructed with four bonded strain gauges connected in full bridge, which was then calibrated at different loading positions. It was found that the change of loading positions on the fork end did not lead to statistically significant difference of voltage output (p=0.9998).
In the main study, electromyographic(EMG) activities of maximum voluntary clenching were firstly obtained by surface electrodes from both sides of masseter, sternocleidomastoid（SCM）, anterior and posterior temporalis muscles at intercuspal position (ICP) and anterior edge to edge position. Then the subjects were instructed to bite at controlled protrusive-retrusive jaw positions with the force transducer placed in the first molar locations of habitual chewing side. The most retrusive jaw position is defined as ?" position, which then determined protrusive 2 and 4 mm jaw positions. At each jaw positions, biting force levels of 50, 100 and 150N, were conducted with visual analog. Each experimental task consists of 3 seconds continuous biting with 5 repeated trials. The magnitude of force was synchronously recorded with EMG activities of masseter, SCM, anterior and posterior temporalis muscles on both sides. Root mean square of muscle activities was derived for each muscle.
The results showed that the arthritic patients revealed lower EMG activities at ICP than the controls whereas no significant difference was found between groups at anterior edge to edge biting position. With GEE model, it was found that muscle activities were positively influenced by bite force magnitude（P＜0.05）in both group. The muscle activities were negatively influenced by protrusive jaw positions only in control group（P＜0.05）, but not significant in patient group. Bite fork position also showed positive influence on ipsilateral muscle activities（P＜0.05）. Besides, muscle recruitment pattern of SCM showed similar tendency as that of masseter muscle during clenching at ICP, while no clear co-activation of masticatory muscles and SCM was found during unilateral bite tasks.
Based on these findings, it can be concluded that the most significant factor influenced the muscle activities was the magnitude of bite force；however, masticatory muscles recruitment did not show significant difference at different jaw position in the patient group.

第一章、前言 1
第二章、文獻回顧
2.1咬力偵測器 6
2.2肌電圖 7
2.3影響肌電圖表現的因子 8
2.4有關咀嚼肌增員狀況之探討 9
2.5胸鎖乳突肌的肌電圖探討 13
第三章、先導實驗
3.1咬力偵測器之製作 16
3.1咬力偵測器的製造 16
3.2不同施力點對咬力偵測器的影響 17
3.2.1測試方法 17
3.2.2結果與統計分析 18
3.2.3.結論 19
第四章、材料與方法
4.1.受測者 20
4.2.不同位置、力量之肌活動記錄 22
4.2.1下顎前突位置導引器 22
4.2.2咬力計 22
4.2.3.肌電圖記錄器 23
4.2.4.實驗步驟 24
4.3訊號處理分析 27
4.2.3.資料擷取 27
4.2.3.統計方法 27
第五章、結果
5.1.影響肌收縮值的因素 32
5.2.不同下顎位置緊咬之最大肌收縮值表現 32
5.2.1.組間之比較 32
5.2.2.組內之比較 33
5.3.肌收縮值與咬力大小的關係 33
5.4.靜態性咬力表現 34
5.4.1.八條肌肉的綜合表現GEE模型分析結果 34
5.4.2.不同咬位的GEE模型分析結果 35
5.4.3.不同組別的的GEE模型分析結果 37
5.4.4.個別肌肉的GEE模式分析結果 38
第六章、討論
6.1.實驗樣本與分析方法 40
6.2.實驗結果的剖析 42
6.2.1.誤差的來源 42
6.2.2.最大肌收縮值 42
6.2.3.靜態性咬力表現 45
6.3.未來展望 47
第七章、結論 49
參考文獻 50
圖表 61
附錄

徐千雯：閉口肌之大小和走向以及顱顏型態對咬力之影響。1.咬肌及內翼肌大小和走向之測取；2.肌骨骼組合與咬力之關係。國立臺灣大學醫學院牙醫科學研究所，齒顎矯正學組，碩士論文，1997.
藍明賢，蕭裕源，吳楷銘，陳坤智：咬力與顱顏形態之關係。中華牙誌（Chin Dent J）1995;14：53-61.