单侧后牙反(牙合)患者的咀嚼肌肌电图分析

目的: 通过对单侧后牙反(牙合)患者咀嚼肌肌电检查,分析单侧后牙反(牙合)对咀嚼功能的影响.方法:用肌电图仪记录20 例(男11 例,女 9 例)单侧后牙反(牙合)患者和20 例(男10 例,女10 例)正常对照组在下颌姿势位、紧咬和双侧咀嚼时咬肌和颞肌前束的肌电数据.计算咬肌的活动不对称指数(ASMM)和颞肌前束的活动不对称指数(ASTA),然后进行统计学分析.结果:在紧咬和双侧咀嚼时,单侧后牙反(牙合)组咬肌和颞肌前束肌电值明显低于对照组(P＜0.05),反(牙合)侧明显低于非反(牙合)侧;单侧后牙反(牙合)组与对照组ASMM和ASTA在紧咬和双侧咀嚼时有显著性差异(P＜0.05);单个后牙反(牙合)组与多个后牙反(牙合)组ASMM和ASTA在紧咬和双侧咀嚼时有显著性差异(P＜0.05).结论:单侧后牙反(牙合)对咀嚼肌功能有明显的影响,应对其进行积极治疗.     

稳定性咬合板治疗颞下颌关节紊乱病的咀嚼肌肌电图研究

目的：通过对颞下颌关节紊乱病（Temporomandibular disorders,TMD）患者进行稳定性咬合板的可逆性咬合治疗,然后利用肌电图仪测量治疗前后患者的咀嚼肌（TA和MM）的肌电情况,分析探讨用稳定性咬合板对颞下颌关节紊乱病患者咀嚼肌肌电图的影响。方法：选取来我院就诊的10例咀嚼肌功能紊乱患者,在稳定性咬合板治疗前和治疗后3个月时,分别用肌电图仪对其咀嚼肌（TA和MM）进行肌电检查,并通过比较治疗前后的咀嚼肌活动不对称指数情况。结果：戴入稳定性咬合板3个月后,颞肌前束与咬肌的MPP和ICP高电位降低（P〈0.05）;最大紧咬时双侧咀嚼肌总体不对称性指数（Astot）、双侧颞肌不对称性指数（ASTA）和双侧咬肌不对称性指数（ASMM）均降低（P〈0.05）。结论：颞下颌关节紊乱病患者通过稳定性咬合板进行咬合治疗后,使患者双侧咀嚼肌的MPP和ICP高电位较治疗前有明显的降低,最大紧咬时双侧咀嚼肌活动不对称性得到明显的改善。     

偏侧咀嚼的咀嚼肌肌电图分析

目的:通过对偏侧咀嚼患者咀嚼肌肌电图的分析,评估:⑴偏侧咀嚼是否会影响咀嚼肌的肌功能状况,⑵这种影响与性别、偏侧咀嚼持续时间的关系。方法:用肌电图仪分别记录16例(男女各8人,平均32.4岁)持续不同时间的偏侧咀嚼组和10例正常对照组在牙列轻接触、中度咬合和最大咬合时的嚼肌和颞肌前束的肌电数据,计算嚼肌的活动不对称指数(ASMM)和颞肌前束的活动不对称指数(ASTA),然后进行统计学分析。结果:⑴偏侧咀嚼组与对照组ASMM和ASTA在中度咬合和最大咬合时,有显著性差异(P<0.05);(2)偏侧咀嚼持续时间为0.5～2年组与5年组ASMM和ASTA无显著性差异(P>0.05);(3)男性组与女性组ASMM和ASTA无显著性差异(P>0.05)。结论:偏侧咀嚼的确会损害咀嚼肌的肌功能状况,但这种损害在5年内没有明显变化且与性别无关。     

偏侧咀嚼对大鼠咀嚼肌肌电图的影响

目的 利用动物模型，观察偏侧咀嚼对咀嚼肌肌电图的影响，从而探讨偏侧咀嚼在颞下颌关节紊乱病发病中的作用。方法 对40只大白鼠拔除右侧上颌后牙造成偏侧咀嚼模型，分成实验l组和实验2组，另外40只作为对照，分成对照l组和对照2组。l组和2组分另1于4周和8周后进行肌电图检查。结果 无论是实验l组还是实验2组，其松弛状态或紧咬时颞肌、咬肌的电位明显高于对照组，并又实验组紧咬时左右咬肌不对称性活动增加，对照组的咬肌肌电活动的对称性明显高于实验组。同时，实验组双侧颞肌和咬肌的肌电图静息期较对照组显著延长。结论 偏侧咀嚼可以对咀嚼肌肌电图造成影响，可能是颞下颌关节紊乱病的病因之一。     

磨牙症患者咀嚼肌肌电特征的研究

目的探讨磨牙症对咀嚼肌功能的影响以及咀嚼肌受损的肌电表现。方法收集24例磨牙症患者和16例无磨牙症学生分别作为磨牙症组和正常组。用Bio PAK口颌功能诊疗系统测量双侧颞肌前束（TA）、咬肌（MM）、二腹肌前腹（DA）和胸锁乳突肌（SCM）在姿势位、牙尖交错位（ICP）最大紧咬和吞咽时的表面肌电活性。结果磨牙症组姿势位时TA和MM的肌电幅值明显高于正常组,而ICP最大紧咬时TA和MM的肌电幅值明显低于正常组,以上差异均有统计学意义（P<0.05）;吞咽时2组各肌肉的肌电幅值没有明显差别。磨牙症组ICP最大紧咬时TA和MM的不对称指数与正常组无统计学差异（P>0.05）。结论磨牙症患者的咀嚼肌功能紊乱主要表现为颞肌前束和咬肌在姿势位呈高电位,而在ICP最大紧咬时呈低电位。     

侧合紧咬的肌电研究

用ＥＭ＿２型肌电仪分别测试１０名男性青年学员在牙尖交错位（ＩＣＰ）最大紧咬，右侧最大紧咬和左侧最大紧咬时咬肌（ＭＭ）和颞肌前束（ＴＡ）的肌电值。结果发现，ＩＣＰ最大紧咬时，双侧同名肌的肌电值无显著差别；例最大紧咬时，工作侧ＴＡ的肌电值大于非工作侧，工作侧ＭＭ的肌电值小于非工作侧；咀嚼习惯、尖牙、组牙及非工作侧能干扰对该结果无明显影响。这对于认识咀嚼肌的功能有重要意义。     

肌电分析在TMD临床疗效评价中的应用

目的:探讨3种不同方法治疗伴有磨牙症TMD的咀嚼肌肌电特征差异,评价3种治疗方法的效果.方法:30例伴有磨牙症的TMD患者被随机分为3组,每组10例.A组进行内毒杆菌毒素A(BTX-A)双侧咬肌肌内注射治疗,B组进行功能训练治疗,C组进行弹性颌垫治疗.对3组研究对象在治疗前、治疗1、3、6个月分别采集双侧咬肌(MM)和颞肌前束(TA)在下颌姿势位(MPP)以及牙尖交错位(ICP)最大紧咬牙时的肌电图(EMG),采用SAS 5.0统计学软件分析比较3组的峰值电位(Amp)之间是否存在统计学差异.结果:横向比较中各个治疗时间段A组患者疼痛视觉模拟评分(VAS)显著低于B组和C组(P＜0.05),肌电显示MPP中A组在治疗过程中能显著降低双侧咬肌肌力(P＜0.05),ICP时A组在1、3个月时显著降低双侧咬肌肌力(P＜0.05),同时双侧颞肌肌力显著增强(P＜0.05).纵向比较中3组在治疗过程中均能明显降低疼痛(P＜0.05),但3组时间点不同,A组缓解疼痛时间较长,肌电图显示3组均可显著降低咬肌MPP肌力(P＜0.05),A、C组可降低ICP咬肌肌力(P＜0.05),A组双侧颞肌肌力可代偿增强(P＜0.05),B、C组颞肌肌力治疗前后均无统计学差异(P＞0.05).结论:临床症状与肌电图的结合使用能够对口颌系统行使功能过程中咀嚼肌的表现进行很好地观测,对TMD患者的咀嚼肌生物力学和结构方面有很好地理解.BTX-A肌内注射方法治疗伴有磨牙症的TMD可显著缓解患者疼痛,疗效持续时间较长.BTX-A肌内注射可显著降低咀嚼肌力,使目标肌肉(咬肌)疲劳得到缓解,促进咀嚼肌力平衡重建,较传统方式存在潜在优势.     

嚼肌B超图象与肌电幅值的对照研究

作者对１０例正常男性青年嚼肌Ｂ超图像与肌电幅值进行了对照研究，作以下测试：（１）采用线阵超声诊断仪记录侧嚼肌在牙尖交错位不咬（静止）和最大紧咬（收缩）时前后径冻结图像，测量视野内肌肉截面积及下颌骨升支前缘处嚼肌厚度；（２）采用肌电图仪记录双侧嚼肌在牙尖交错位作最大紧咬时的肌电图，测量峰值，结果表明Ｂ超图像所测嚼肌静止面积，收缩面积有收缩厚度均与嚼肌肌电值有明显线性正相关关系，作者认为Ｂ超测量活体肌     

广泛型侵袭性牙周炎患者咀嚼肌肌电特征研究

目的:分析广泛型侵袭性牙周炎(GAgP)患者咀嚼肌肌电活动,并以正常人为对照,探讨GAgP患者咀嚼肌肌电表现及对咀嚼肌功能的影响。方法:测量并记录正常组和牙周炎组双侧颞肌前束(TA)、咬肌(MM)、二腹肌前腹(DA)及胸锁乳突肌(SCM)在下颌不同位置时肌电值。利用配套软件进行肌电值分析,获得连续肌电值的平均值,计算肌电值不对称指数。比较两组咀嚼肌肌电值有无统计学差异;比较两组在最大紧咬时,TA和MM肌电值不对称指数有无统计学差异。结果:在下颌姿势位时,牙周炎组的TA、MM、DA和SCM的肌电值均大于正常组;在牙尖交错位( ICP)最大紧咬时,牙周炎组TA、MM肌电值均小于正常组(P＜0.001);在下颌姿势位时,牙周炎TA、MM、DA和SCM均有微小肌电活动,其中TA＞MM＞DA;最大紧咬时TA＞MM;前伸运动时DA＞MM＞TA;后退位时 DA＞MM,TA＞MM,差异均有统计学意义(P＜0.05);ICP最大紧咬时,牙周炎组较正常组左右侧TA和MM肌电值不对称指数高,并且存在统计学差异(P＜0.05)。结论:GAgP患者因牙周组织受损而降低了咀嚼功能,存在咀嚼活动不平衡及肌肉功能异常。     

口腔医学基础/口腔解剖生理学

去卵巢雌性大鼠颏舌肌肌功能特征的研究;陕西陇县出±2000年前人牙齿的形态学研究;青年女性浅层咬肌B超形态与颅颌面形态关系的研究;肌电图在偏侧咀嚼研究中的应用;侧（牙合）运动中正常磨牙动态（牙合）力变化特点的研究;咬合重建对牙齿重度磨耗患者咀嚼运动模式的影响;头位左倾和右倾变化对咀嚼肌肌电的影响;     

肌电图在偏侧咀嚼研究中的应用

目的 使用肌电仪研究偏侧咀嚼对咀嚼肌功能的影响.方法 选择20名女性受试者,分为两组,实验组10名右侧咀嚼和对照组10名正常咀嚼者,引导她们分别在牙间交错位(ICP)进行牙列轻接触和最大咬合,用肌电图仪记录下嚼肌和颞肌前束的肌电信号数据,进行统计学分析.结果 最大咬合时,实验组的右嚼肌的肌电电位明显小于对照组(P＜0.05).结论 右侧咀嚼的患者有侧嚼肌的活动较双侧咀嚼者明显减少.     

咬合支持丧失患者修复前后咀嚼肌表面肌电分析

目的：探讨咬合支持丧失患者修复前后咀嚼肌肌电的变化。方法：对24例咬合支持丧失患者进行常规修复,记录不同时期双侧咬肌和颞肌前束在下颌姿势位及牙尖交错紧咬位时的肌电活动,分析肌电幅值、不对称指数及咬肌/颞肌活动指数的变化。结果：（1）修复前后下颌姿势位肌电变化,咬肌肌电幅值和不对称指数在不同时期无明显变化（P〉0.05）;颞肌肌电幅值和不对称指数在义齿戴用3个月以上后显著小于义齿早期（P〈0.05）;咬肌/颞肌前束活动指数在各时期均小于0。（2）修复后牙尖交错位紧咬时肌电变化,咬肌及颞肌前束肌电幅值在戴牙3个月后显著高于戴牙早期（P〈0.05）;不对称指数与初戴牙时接近（P〉0.05）,较戴牙1周及1个月显著减小（P〈0.05）。咬肌/颞肌前束活动指数值在各时期均接近0。结论：咬合支持丧失患者进行咬合重建过程中,咀嚼肌肌电活动在不同时期有所变化。肌电测量可为咬合重建效果的评价提供参考。     

Maximal bite force and EMG during bilateral and unilateral clenching

The observed maximal bite force is known to depend on the measuring method employed. Bite position, bite rise and unilateral or bilateral biting influence the observed bite force. The maximal bite force obtained when clenching unilaterally is smaller than the bite force summed for the two sides of a bilateral measurement ( Bakke et al., 1989 ). We determined bite force and muscle activity of the masseter and temporal muscles during maximal voluntary contraction in a group of 81 dentate subjects. The bite force was measured between the first molars both bilaterally and unilaterally. The summed bite force obtained from the bilateral measurement was 569 ± 170 N. The bite force obtained for unilateral clenching was significantly lower: 430 ± 142 N. No significant differences in bite force between the right and left side for both the bilateral and unilateral measurements were observed. The muscle activity of the masseter and temporal muscles obtained from bilateral clenching did not differ significantly (masseter: 248 ± 149 μV and temporalis: 232 ± 105 μV). Also no significant differences were observed in muscle activity between the right and left side during bilateral clenching. We observed a significantly lower muscle activity in both masseter and temporalis for unilateral clenching as compared with bilateral clenching. The results of unilateral clenching showed no differences in muscle activity between the ipsi‐ and contralateral side for the masseter muscle (186 ± 127 μV). However, the muscle activity at the ipsilateral side of the temporal muscle (197 ± 127 μV) was significantly higher than at the contralateral side (150 ± 81 μV). We may conclude that bilateral clenching yields bite forces that are over 30% larger than those obtained during unilateral clenching. The muscle activity during unilateral clenching is symmetrical in the masseter muscles, but asymmetrical in the temporal muscles.     

Bite force and electromyograpy during maximum unilateral and bilateral clenching

Maximum voluntary bite force has often been studied as an indicator of the functional state of the masticatory system. Bilateral, as well as unilateral, methods have been used to determine bite force. Only a few studies have compared the outcomes of both methods. The aim of this study was to measure bite force and jaw-muscle activity during bilateral as well as unilateral maximum clenching in a large number of healthy subjects, so that the results could be compared. In a group of 81 dentate subjects we observed an average bilateral bite force of 569 N. The average unilateral bite force was significantly lower, being 430 N (right) and 429 N (left). Masseter and anterior temporal muscle activities were also significantly lower during unilateral clenching as compared with bilateral clenching. The masseter muscles showed no difference in activity between the ipsilateral side and the contralateral side during unilateral clenching. In contrast, the activity of the anterior temporal muscle on the ipsilateral side was significantly higher than on the contralateral side. Thus, the change in the forces acting on the jaw during unilateral clenching compared with bilateral clenching leads to a different response in the temporal muscles than in the masseter muscles.     

The influence of altered working-side occlusal guidance on masticatory muscles and related jaw movement

The effect of four different occlusal situations (group function, canine guidance, working side occlusal interference, and hyperbalancing occlusal interference) on EMG activity in jaw elevator muscles and related mandibular movement was investigated on 12 subjects. With a computer-based system, EMG and displacement signals were collected simultaneously during specific functional (unilateral chewing) and parafunctional tasks (mandibular gliding movements and various tooth clenching efforts) and analyzed quantitatively. When a naturally acquired group function was temporarily and artificially changed into a dominant canine guidance, a significant general reduction of elevator muscle activity was observed when subjects exerted full isometric tooth-clenching efforts in a lateral mandibular position. The original muscular coordination pattern (relative contraction from muscle to muscle) remained unaltered during this test. With respect to unilateral chewing, no significant alterations in the activity or coordination of the muscles occurred when an artificial canine guidance was introduced. Introduction of a hyperbalancing occlusal contact caused significant alterations in muscle activity and coordination during maximal tooth clenching in a lateral mandibular position. A marked shift of temporal muscle EMG activity toward the side of the interference and unchanged bilateral activity of the two masseter muscles were observed. The results suggest that canine-protected occlusions do not significantly alter muscle activity during mastication but significantly reduce muscle activity during parafunctional clenching. They also suggest that non-working side contacts dramatically alter the distribution of muscle activity during parafunctional clenching, and that this redistribution may affect the nature of reaction forces at the temporomandibular joints.     

Effects of occlusal splints on the asymmetry of masticatory muscle activity during maximal clenching

summary The effects of stabilization splints on the electromyographic activity patterns of the masseter and anterior temporal muscles during maximal clenching in healthy subjects and subjects with different types of stomatognathic dysfunction syndrome were investigated. No marked effect of splints on the asymmetry of muscle activity during bilateral clenching was revealed immediately after splint insertion. During unilateral clenching in the intercuspal position (ICP), the relative asymmetry index (rAI) of the masseter muscles, detecting the imbalance of left and right muscular activity, was significantry increased. The use of splints suppressed the asymmetry of masseter muscle activity during unilateral clenching. This result suggests that the use of a splint is a method of suppressing clench-caused aggravation of stomatognathic dysfunction in the presence of an imbalance between left and right muscle activities.     

Balance in masticatory muscle activity during natural chewing and submaximal clenching

The balance in the electromyographic (EMG) activities of the left and the right masseter and the left and right anterior temporal muscles during chewing and during submaximal clenching at 10% and 50% of the maximum voluntary contraction in the inter-cuspal position was investigated in twenty healthy adults. Muscular asymmetry patterns during chewing and clenching were positively correlated for both pairs of masticatory muscles investigated at the 50% level (P less than 0.01-P less than 0.001) and for the masseter muscles, also at the 10% level (P less than 0.01). Stronger correlations in muscular asymmetry were found for the masseter muscles and at the higher submaximal clenching level. In general, the masseter muscles displayed a greater degree of asymmetric activity than the anterior temporal muscles during both chewing and clenching (0.05 less than P less than 0.1-P less than 0.025). The average EMG amplitudes of both masseter or both anterior temporal muscles within each subject showed no correlation between clenching and chewing. The correlations between muscular asymmetries observed during static (clenching) and dynamic (chewing) conditions suggest that there are common factors influencing these activities.     

基于非线性动力学的咀嚼肌表面肌电信号相空间重构

目的 通过非线性动力学的方法,对咬肌和颞肌前束表面肌电(surface electromyography,sEMG)信号进行相空间重构,探求sEMG轨迹变化规律.方法 选择口颌系统基本正常的个体,男女各10名,在牙尖交错位(intercuspal position,ICP)紧咬时采集左右咬肌和颞肌前柬sEMG信号,基于Matlab平台开发咀嚼肌sEMG非线性动力学分析程序,用C-C法计算时延和嵌入维,再用主成分分析法重构sEMG信号的相空间图.结果 咀嚼肌sEMG非线性动力学分析程序可对20名个体的双侧咬肌和颞肌前束sEMG信号进行处理分析,重构的sEMG信号相空间图显示,正常个体在ICP紧咬时咬肌和颞肌前束的sEMG信号呈现出典型的混沌吸引子的形态特征.结论 咬肌和颞肌在ICP紧咬时sEMG具有混沌特征,适合用非线性动力学方法进行分析.     

Neuromuscular coordination of masticatory muscles in subjects with two types of implant-supported prostheses

OBJECTIVES: To compare the electromyographic (EMG) characteristics of masticatory muscles in patients with fixed implant-supported prostheses and implant overdentures. MATERIAL AND METHODS: Nineteen subjects aged 45-79 years were examined. Fourteen were edentulous and had been successfully rehabilitated with (a) maxillary and mandibular implant-supported fixed prostheses (seven patients); (b) mandibular implant overdentures and maxillary complete dentures (seven patients). Five control subjects had natural dentition or single/partial (no more than two teeth) tooth or implant fixed dentures. Surface EMG of the masseter and temporal muscles was performed during unilateral gum chewing and during maximum teeth clenching. To reduce biological and instrumental noise, all values were standardized as percentage of a maximum clenching on cotton rolls. RESULTS: During clenching, temporal muscle symmetry was larger in control subjects and fixed implant-supported prosthesis patients than in overdenture patients (analysis of variance, P=0.005). No differences were found in masseter muscle symmetry or in muscular torque. Muscle activities (integrated areas of the EMG potentials over time) were significantly larger in control subjects than in implant-supported prosthesis patients (P=0.014). In both patient groups, a poor neuromuscular coordination during chewing, with altered muscular patterns, and a smaller left-right symmetry than in control subjects were found (P=0.05). No differences in masticatory frequency were found. CONCLUSION: Surface EMG analysis of clenching and chewing showed that fixed implant-supported prostheses and implant overdentures were functionally equivalent. Neuromuscular coordination during chewing was inferior to that found in subjects with natural dentition.