交变应力对大鼠翼外肌成肌细胞形态学改建的影响

目的 评价不同交变应力作用下大鼠翼外肌成肌细胞的形态学改建,从而探讨矫形治疗中成肌细胞的改建机制。方法 在自行研制脉动式细胞力学系统基础上,将大鼠翼外肌成肌细胞在膜交变应力培养小室内培养并进行鉴定,分别施加2.5 kPa、5.0 kPa和10.0 kPa交变力学刺激,于加力后6 h和12 h用倒置相差显微镜观察细胞形态学变化。结果 成肌细胞形态在交变应力加载前后由无规律延伸向与张应力平行方向上转化;在较低的应变水平（2.5 kPa、5.0 kPa）作用下成肌细胞排列方向主要沿张应变方向,而在较大的应变水平（10.0 kPa）作用下成肌细胞排列方向具有较多的沿张应变垂直方向变化的趋势。结论 不同的交变应力对大鼠翼外肌成肌细胞形态学改建具有一定的影响,在一定范围内的交变应力可以促进成肌细胞在二维方向的排列。     

功能矫形前伸下颌后大鼠翼外肌胰岛素分布的免疫组织化学研究

目的：研究功能矫形治疗工外肌内胰岛素的分布规律和定位。方法：采用免疫组化ABC法，对青春生长期雄性SD大鼠功能矫形前伸下颌后翼外肌内胰岛素的分布和规律定位和半定量研究，结果：翼外肌内胰岛素定位于肌细胞膜上；功能矫形前伸下颌后，大鼠翼外肌内胰岛素的分布增加。结论：胰岛素在功能矫形前伸下颌后翼外肌的适应性改建中有重要作用。     

功能矫形前伸大鼠下颌后翼外肌胰岛素含量变化的定量研究

目的：了解功能矫形前伸大鼠下颌后胰岛素对翼外肌适用性改建的作用。方法：采用放射免疫分析技术分别检测实验组和对照组大鼠翼外肌内胰岛素的含量。结果;功能矫形前伸下颌后,生长期大鼠外肌内胰岛素含量增加。结论：胰岛素在功能矫形前伸大鼠下颌后翼外肌的适应性改建中有重要作用。     

张应力对面颌肌细胞烟碱样乙酰胆碱受体基因表达影响的体外研究

目的评价张应力作用后面颌肌细胞烟碱样乙酰胆碱受体基因表达变化。方法采用已经建立的面颌部肌细胞体外力学刺激—细胞培养模型,半定量RT-PCR技术检测nAChRα1亚基基因加力前后转录水平变化。结果未发现有明显统计学差异。结论单纯张应力对体外培养小鼠颌面部骨骼肌细胞nAChR基因表达影响较小。     

周期性牵张面颌致成肌细胞内Ca2+浓度变化的研究

目的观察牵张引起的成肌细胞内Ca2+浓度变化,探求口腔正畸功能矫形治疗中肌肉改建机制。方法采用四点弯曲加力装置,使体外培养的SD大鼠面颌部成肌细胞发生牵张变形后,测定加力后不同时段及在镜下给予乙酰胆碱(Ach)后成肌细胞内Ca2+荧光强度的变化。结果牵张引起的成肌细胞内Ca2+荧光强度的升高明显高于Ach的作用,并且在经历了体外的牵张加力后,Ach刺激并未使成肌细胞内Ca2+荧光强度出现预先设想的叠加效果,在各个不同的实验组中Ca2+荧光强度反而略有下降。结论牵张引起的骨骼肌细胞内Ca2+浓度升高的机制不同于肌肉兴奋收缩耦联过程中出现的Ca2+浓度升高,Ca2+作为第二信使引发的细胞内各种结构和功能蛋白的改变可能参与了肌肉改建过程。     

翼外肌的解剖,功能与功能紊乱

翼外肌与颞颌关节关系密切，其功能状态可影响颞颌关节的结构和功能。对翼外肌的解剖，功能及功能紊乱，在多数学者认为，翼外肌分为上，下两头，上头纤维附着于关节盘和关节盘和关节囊，部分纤维附着于髁突，下头纤维则附着于髁突颈部；翼外肌上头具有闭口肌的特性，而下头则属开口肌，上下头共同发挥稳定关节盘等结构，协同关节运动的作用；翼外肌功能紊乱可导致关节结构和功能紊乱，其中翼外肌上头功能紊乱是关节盘前移位的重要原     

翼内肌,二腹肌在下颌运动中作用的肌电研究

使用沪产ＪＤ－２型肌电图仪，用单极同心针电极对翼内肌，二腹肌（前腹、下同）在各个颌位和咀嚼运动时的肌电图进行同步记录分析。结果显示翼内肌是强有力的升颌肌，除具升颌作用外，还参与对侧边缘运动和最大前伸运动。二腹肌首先是降颌肌，它也参与下颌侧方边缘运动、下颌前伸运动和后退运动，同时，它具有维持下颌姿势和拮抗升颌肌的作用。咀嚼运动中翼内肌、二腹肌作用都十分明显，呈交替活动，并且该二肌有仉放电始点与终点的     

翼外肌的解剖、功能与功能紊乱

翼外肌与颞颌关节关系密切,其功能状态可影响颞颌关节的结构和功能。对翼外肌的解剖、功能及功能紊乱,目前大多数学者认为,翼外肌分为上、下两头,上头纤维附着于关节盘和关节囊,部分纤维附着于髁突,下头纤维则附着于髁突颈部;翼外肌上头具有闭口肌的特性,而下头则属开口肌,上下头共同发挥稳定关节盘等结构,协同关节运动的作用;翼外肌功能紊乱可导致关节结构和功能紊乱,其中翼外肌上头功能紊乱是关节盘前移位的重要原因之一。     

功能性矫治器引导下颌前伸对其咀嚼肌生物力学特性的影响

目的：探讨在功能性颌骨矫形过程中，咀嚼肌生物力学特性变化的规律。方法：选用３０只４周龄Ｗｉｓｔａｒ雄性大鼠，多为实验组和对照组，实验组每日戴功能矫治器１０ｈ～１２ｈ，对照组不戴。４周后应用力学测试方法对嚼肌、二腹肌前腹、翼外肌生物力学特性的变化进行定量分析。结果：咀嚼肌收缩性质发生明显变化，翼外肌收缩张力增强，收缩速度减慢，二腹肌前腹收缩张力减弱，收缩速度加快。结论：表明功能性矫治器是通过改变翼外肌、二腹肌等口颌系统肌肉的功能活动，促进颌骨生长改建，从而达到功能性颌骨矫形目的。     

功能矫形前伸下颌后幼年大鼠下颌前伸肌的组织化学研究

采用酶组织化学方法,观察功能矫形前伸下颌后大鼠翼外肌和浅层嚼肌细胞内线粒体酶代谢的变化规律。结果显示,翼外肌氧化型纤维构成明显增多,浅层嚼肌氧化型纤维明显减少。表明翼外肌参与维持下颌姿势位的张力活动增加,浅层嚼肌则位相活动增加。     

The human lateral pterygoid muscle

One of the jaw muscles particularly implicated in temporomandibular disorders (TMD), a common form of non-dental chronic orofacial pain, is the human lateral pterygoid muscle. The precise role of this muscle in TMD is unclear as is the nature of the interaction between pain and motor function particularly involving this muscle. This research group has adopted a two-stage approach to studying the effects of pain on motor function. The first is to study normal orofacial motor function through recordings of jaw movement and electromyographic (EMG) activity from a number of jaw muscles (including recordings from the lateral pterygoid muscle; verification of electrode location achieved through computer tomography imaging) during a number of standardised jaw movements. These studies have defined the detailed functional properties of, in particular, the lateral pterygoid muscle, whose physiology and function is not well understood. In summary, the data are consistent with the hypothesis previously proposed that the lateral pterygoid should be regarded as a system of fibres that acts as one muscle, with varying amounts of evenly graded activity throughout its entire range, and with the distribution of activity within the muscle being determined by the biomechanical demands of the task. Our second approach has been to study the effects of experimental masseter muscle pain on the detailed functional properties (e.g., root-mean-square EMG activity) of the jaw muscles, especially the lateral pterygoid muscle. Preliminary data from these pain studies point towards significant effects of human experimental muscle pain on jaw muscle activity and jaw movement.     

The human lateral pterygoid muscle: a review of some experimental aspects and possible clinical relevance

The clinical notion that some disturbance to the activity of the lateral pterygoid muscle plays a role in the aetiology of temporomandibular disorders (TMD) is still widely accepted and influences management strategies. However, there is no rigorous scientific evidence to support this clinical notion and the role of the lateral pterygoid muscle in normal function is still controversial. The classically defined functions of each head of the muscle are that the superior head is active on closing, retrusion, and ipsilateral jaw movements, while the inferior head is active on opening, protrusion and contralateral jaw movements. However, recent data indicate that these concepts are too simplistic. For example, recent evidence suggests that parts of the superior head may also be active on opening, protrusion and contralateral jaw movements, and that the superior head may consist of three mediolaterally arranged functional zones. Given these complexities, the proposal that clicking and/or locking conditions arise in the temporomandibular joint through some form of lack of co-ordination between the two heads of the muscle needs re-evaluation. Despite earlier reports to the contrary, both heads of the lateral pterygoid muscle appear to be electrically silent at the postural or resting jaw position, and therefore appear to play no role in the anteroposterior positioning of the jaw at the postural position. An important role has also been demonstrated electromyographically for progressive changes in activity in the inferior head as the direction of horizontal jaw force shifts from one side to the other. This suggests an important role for the lateral pterygoid muscle in the generation of side-to-side and protrusive jaw forces. The lateral pterygoid muscle is likely therefore to play an important role in parafunctional excursive jaw movements and also possibly a role in influencing jaw position in patients where the maxillomandibular relationship records change from session to session. The above data provide new insights into the normal function of the lateral pterygoid muscle. The proposal that the lateral pterygoid muscle plays some role in the aetiology of TMD needs now to be rigorously tested.     

交变应力对大鼠翼外肌成肌细胞增殖活性的影响

目的探讨不同交变应力作用下,大鼠翼外肌成肌细胞增殖活性的变化,为交变应力下翼外肌组织的改建提供必要的基础实验数据。方法在自行研制的脉动式细胞力学系统基础上,将大鼠翼外肌成肌细胞在膜交变应力培养小室内进行培养,分别施加2.5、5.0、10.0 kPa交变力学刺激于不同频率组,3H- TDR检测成肌细胞增殖活性,并将结果进行统计学处理分析。结果高频组不同大小的交变应力都有促成肌细胞增殖的趋势,与空白组比较具有明显的促增殖作用（P<0.05）;在交变应力作用12 h后,不同频率组间比较的规律与6 h后基本一致,但是较6 h具有更大的增殖活性变化。低频组组间的增殖活性变化规律基本与高频组一致,但低频组有更大的促增殖效应。结论低频率比高频率具有较高的促成肌细胞增殖活性;随着交变应力作用时间的延长,成肌细胞增殖活性在较低应变范围内（≤5.0 kPa）随应变的加大而增加,较大应变具有较小的成肌细胞增殖活性增加趋势。     

功能矫形前伸青春期大鼠下颌对翼外肌Na＋／K＋-ATPase功能活性的影响

目的：研究功能矫形前伸青春期大鼠下颌对翼外肌Na＋／K＋-ATPase功能活性的影响。方法：选用5w龄雄性SD大鼠70只，随机分为实验组和对照组，并各分为7个时间段，其中实验组大鼠佩戴可摘式上颔斜面导板功能矫治器。在不同的时间段，分别测定大鼠翼外肌Na＋／K＋-ATPase功能活性。结果：自矫治器佩戴第1-42d，实验组与对照组相比，Na＋泵活性均有显著性差异。Na＋泵活性自第1d开始上调，第21d达到最高峰，之后开始回落，在第28d、42d仍显著高于对照组。结论：生长发育对Na＋／K＋-ATPase功能活性没有显著影响，功能矫形治疗使翼外肌Na＋／K＋-ATPase功能活性产生了适应性增高。     

Perspectives On the Role of the Lateral Pterygoid Muscle and the Sphenomandibular Ligament in Temporomandibular Joint Function

The lateral pterygoid muscle plays an important role in the movement of the mandible and has been studied from several points of view, including structural and functional anatomy. What matters clinically is the relative position of the muscle fibers attached medially to the mandibular condyle. In the following study, we observed not only the attachment of the lateral pterygoid muscle fibers to the articular disk, but also the relative position of the mandibular condyle to a base line set up on the mandibular condyle. According to our observations, the lateral pterygoid muscle fibers attach to the articular disk at the inner point of the medial pole. Based on this finding, we can say that the muscle fibers can both draw the articular disk anteriorly and balance it by supporting it posteriorly. That is to say, the lateral pterygoid muscle has two actions: to elevate the articular disk anteriorly and to support the articular disk. Furthermore, the sphenomandibular ligament has continuity with the articular disk tissue medially. This relationship suggests that the ligament fibers attached to the articular disk draw the disk posteriorly in its course of mandibular closing, thus enabling the articular disk to move smoothly.     

Electromyography after lateral pterygoid myotomy in monkeys.

Neuromuscular patterns of five female rhesus monkeys (Macaca mulatta) were studied to determine the effect of laternal pterygoid myotomy on the function of selected groups of masticatory muscles. Activity characteristics of the lateral pterygoid muscle were recorded as early as four days postoperatively. By the end of the second postoperative month, bilateral lateral pterygoid muscle activity was demonstrated in all animals. In all cases, it closely resembled preoperative patterns of lateral pterygoid muscle function. The activity was observed regardless of whether an inert barrier was used to prevent reattachment of the muscle. The results of this study indicate that the lateral pterygoid myotomy does not have a long-term effect of inhibiting the function of the lateral pterygoid muscle.     

The feasibility of palpating the lateral pterygoid muscle

Although dysfunction of the lateral pterygoid muscle could contribute to the pain associated with TMJ disorders, it has been demonstrated through the use of dissections and lateral head radiographs that it is not possible to palpate the lateral pterygoid muscle directly by conventional clinical techniques without applying pressure through the overlying superficial head of the medial pterygoid muscle. The possibility of confusing temporal muscle hypersensitivity with that of another muscle in this region is suggested.