上颌骨缺损患者手术前后咀嚼运动时脑血流的变化研究

目的:测量上颌骨缺损患者手术前后咀嚼运动时脑血流的变化,探讨上颌骨缺损所致咀嚼功能降低与脑血流变化的关系.方法:选取因肿瘤手术切除将导致上颌骨缺损的患者16例,应用经颅多普勒超声探测仪,测量其手术前不咀嚼、空咀嚼5min、10min三个时段的大脑中动脉(MCA)收缩期峰流速(Vs)、舒张期末峰流速(Vd)、平均峰流速值(Vm).在患者手术后约2个月(永久赝复体修复前),再分别测量相应的数值.采用SPSS13.0进行重复测量数据的方差分析.结果:手术因素对于Vs、Vd的影响差异无统计学意义(P＞0.05),而对于Vm有明显的影响(P＜0.05).时间因素对Vs、Vd、Vm的影响差异有统计学意义(P＜0.05).随着咀嚼时间的延长,峰流速均数增加.时间因素与手术因素(即术前和术后)对Vs、Vd、Vm的影响有交互作用(P＜0.05).结论:切除术前和术后,空咀嚼运动均有促使其大脑中动脉脑血流量增加的作用,且随咀嚼运动时间延长(累计咀嚼10min),脑血流速呈加快趋势.与术前相比,切除术后咀嚼运动时大脑中动脉血流量降低.     

老年人和青年人咀嚼前后脑血流变化的对照研究

目的：通过对老年人和青年人咀嚼前后脑血流变化的对照研究,观察咀嚼运动对脑血流的影响。方法：应用经颅多普勒超声诊断仪探测老年人和青年人大脑中动脉的收缩期峰流速、舒张期末峰流速及平均峰流速,进行方差分析。结果：两组受试者在咀嚼5min后、咀嚼10min后的收缩期峰流速、舒张期末峰流速及平均峰流速均高于咀嚼前,并有显著性差异（P〈0．05）。在各时间段上,老年人除在舒张期峰流速均数低于青年人外,在收缩期峰流速均数和平均峰流速均数与青年人无显著性差异。结论：老年人正常咀嚼功能时脑血流指标趋向与青年组脑血流指标相似,提示咀嚼运动对老年人脑血流量增加同样有促进作用。     

老年人咀嚼前后脑血流变化的对照研究

目的；通过对老年人咀嚼前后脑血流变化的对照研究，探讨咀嚼运动对脑血流的影响。方法：应用经颅多普勒超声诊断仪探测老年人大脑中动脉的收缩期峰流速、舒张期末峰流速及平均峰流速，SPSS10．0统讣软件进行重复测量数据的方羌分析。结果：咀嚼5分钟和10分钟后的收缩期峰流速、舒张期末峰流速及平均峰流速均高于咀嚼前，有硅著性差异（P〈0．05）。结论：咀嚼运动可明显提高老年人大脑中动脉的血流速度，增加栩应脑区的供血量。年龄因素虽然被证实可以降低大脑中动脉的血流速度，但是咀嚼功能正常可以减少这种影响。     

咀嚼运动前后脑血流变化的研究

目的：观察咀嚼运动前后脑血流的改变，探讨这些变化的意义。材料与方法：应用超产多谱勒探测仪探测咀嚼前和咀嚼10分钟后脑血流的改变，对所测大脑中动脉的收缩期峰流速、舒张期末峰流速、平均峰流速进行对比分析。结果：咀嚼运动后大脑中动脉收缩期峰流速、舒张期末峰流速及平均峰流速较咀嚼运动前均有明显增加。结论：咀嚼运动可使脑血管的血流流速增加，使脑血流量增多，在促进脑的发育及功能的行使方面有重要作用。     

咀嚼对无牙颌患者脑血流动力学影响的研究

目的 观察无牙颌患者咀嚼运动前后脑血流的改变,探讨咀嚼对脑血流动力学的影响.方法 应用经颅彩色多谱勒超声扫描仪,探测30名戴用全口义齿3个月内的无牙颌患者,在安静状态下及戴用全口义齿和不戴义齿咀嚼无糖口香糖10min后脑血流速的改变,对大脑中动脉收缩期峰流速、舒张期末峰流速、平均峰流速进行统计分析.结果 30名无牙...     

生物功能性全口义齿修复对无牙颌患者脑血流量的影响

目的 通过检测无牙颌患者进行生物功能性全口义齿修复后不同时间点大脑中动脉血流速度的变化,探讨生物功能性全口义齿修复治疗对脑血流量的影响作用。方法 选择临床无牙颌患者,进行生物功能性全口义齿修复治疗,应用TCD经颅多普勒彩色超声诊断仪分别对患者进行义齿修复前和修复后当天、3个月、6个月在平静和咀嚼运动状态下的大脑中动脉收缩期峰流速（VS）、舒张期末峰流速（Vd）及平均峰流速（Vm）值检测。结果 平静状态下,修复治疗后6个月,Vm、VS和Vd均出现显著提高（P＜0.05）。在咀嚼运动状态下,咬合重建修复后3个月,VS 和Vm均出现明显提高;治疗后6个月,Vd也显著提高（P＜0.05）。结论 生物功能性全口义齿修复治疗可以提高无牙颌患者大脑中动脉血流速度,对改善患者脑血流量和脑功能有促进作用。     

颞下颌关节紊乱病咬合板治疗前后脑血流变化的初步探讨

目的：通过咬合板治疗前后咀嚼运动时脑血流变化的测定，探讨咬合板在治疗颞下颌关节紊乱病（TMD）时脑血流的变化。方法：使用德国DML系列multidopX1经颅多普勒超声诊断仪测定脑血流的改变。对大脑中动脉的收缩期峰流速，舒张期末峰流速与平均峰流速进行对比分析。结果：病例组和对照组在行使咀嚼运动后，大脑中动脉的血流明显增加。未戴咬合板和戴咬合板的TMD患者咀嚼运动后，脑血流速无明显改变。结论：咀嚼运动可以促进脑部血液循环，咬合板对大脑中动脉血流速影响不大。     

游离端缺牙对老年人脑血流的影响

目的：通过对游离端缺牙老年人和无缺牙老年人咀嚼运动不同时段脑血流变化的测定,探讨游离端缺牙对老年人脑血流的影响.方法：从临床选择双侧游离端缺牙患者16例,应用经颅多普勒超声探测仪,记录其咀嚼前、咀嚼5min和咀嚼10min3个时段的大脑中动脉脑血流数值,并与16例无缺牙老年人相应时段的脑血流流速作对照研究.结果：病例组与对照组成组t检验结果显示：病例组与对照组3个时段的Vs、Vd、Vm值均有显著差异（P＜0.05）,在3个实验时段上对照组的Vs、Vd、Vm均数值都高于病例组相应Vs、Vd、Vm均数值.结论：游离端缺牙患者其脑部血流的供应与无缺牙组相比有减少趋势,由缺牙造成的咀嚼功能下降可导致老年人脑血流减少.     

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目的    探讨可摘式局部义齿咬合重建修复对脑血流的影响。方法    选择2008年1月至2010年1月在山西医科大学口腔医院修复科就诊的需进行咬合重建修复的患者20例,在咬合重建前后分别应用经颅多普勒超声诊断仪探测患者大脑中动脉（MCA）的收缩期峰流速、舒张期末峰流速及平均峰流速,并进行比较分析。结果    20例患者进行咬合重建后,咀嚼前与咀嚼后MCA的收缩期峰流速、收缩期末峰流速及平均峰流速均比咬合重建前增加,且差异有统计学意义（P < 0.05）。结论    咬合重建修复可提高患者MCA的血流速度,增加相应脑区的供血量。     

游离端缺牙患者义齿修复前后咀嚼运动时脑血流的变化研究

目的：探讨游离端缺牙患者可摘局部义齿修复前后咀嚼运动不同时段脑血流变化。方法：从临床选择双侧游离端缺牙患者16例,应用经颅多普勒超声探测仪,记录其咀嚼前、咀嚼5min和咀嚼10min三个时段的大脑中动脉脑血流数值,在患者可摘局部义齿修复1个月后,再分别测量其三个时段的脑血流数值,比较修复前后咀嚼运动不同时段脑血流流速的变化。结果：患者修复前后配对t检验结果显示：游离端缺牙患者修复前、后咀嚼5min的Vs、Vd、Vm值均有显著差异（P〈0．05）,修复前、后咀嚼10min的Vd、Vm值有显著差异（P〈0．05）。结论：可摘局部义齿的修复恢复了游离端缺牙患者的咀嚼功能,脑部供血量有所增加,咀嚼运动具有促使老年人脑血流量增加的趋势。     

全口义齿垂直距离恢复过低对脑血流的影响

目的研究全口义齿垂直距离恢复过低对脑血流的影响。方法选取10例无牙颌患者,应用经颅多普勒超声诊断仪,探测全口义齿垂直距离恢复过低患者（降低5 mm）在咀嚼前、咀嚼10 min和咀嚼20 min时大脑中动脉的平均峰流速度、收缩期峰流速度和舒张期末峰流速度。试验采取自身前、后对照,应用SPSS18.0软件包对数据进行独立样本t检验和方差分析。结果试验组在咀嚼前、咀嚼10 min和咀嚼20 min时的血流速度无显著变化,而对照组血流速度显著升高。试验组在咀嚼10 min后血流速度显著性低于对照组,咀嚼20 min后血流速度无显著变化。结论全口义齿垂直距离恢复过低患者在咀嚼运动时脑血流无显著增加。     

Influence of human jaw movement on cerebral blood flow

Temporal changes in cerebral blood flow induced by jaw movement have yet to be investigated. To assess the influence of pattern and intensity of muscle contraction during jaw movement on task-induced change in cerebral blood flow, we performed bilateral transcranial Doppler ultrasound examination during clenching, gum chewing, and tooth tapping in healthy volunteers. A random-effects model analysis revealed a significant increase in middle cerebral artery blood flow velocity during clenching (high muscle activity) and gum chewing (moderate muscle activity), compared with the preceding rest period; however, such an increase was not detected during tooth tapping (low muscle activity). Cerebral blood flow was greater on the working side during the intensive isometric contraction of the masseter muscle in clenching. These results suggest that task-induced change in cerebral blood flow during jaw movement is influenced by the change in peripheral circulation evoked by muscle contraction.     

Masticatory jaw movement optimization after introduction of occlusal interference

Summary How ‘control’ characteristics of masticatory jaw movement, such as skilfulness of the movement, change after alteration in occlusion remains uncertain. For each of 10 healthy adults with good occlusion, an occlusal interference with artificial ‘tooth‐cusp’ was introduced to the crown of the upper molar tooth on the non‐working side of unilateral chewing. Mandibular incisor‐point movements were then recorded by a 3D tracking device. The introduction of the occlusal interference induced a remarkable increase in the normalized jerk‐cost (NJC), prolonged duration of the decelerative phase and lowered peak velocity for jaw closing movement during chewing. Overall, the NJC and velocity profile showed significant recoveries during the course of about 90 repetitive chewing cycles performed under the altered occlusal condition. These findings suggest that acute adaptive changes of jaw motion after introduction of occlusal interference might be characterized as the recovery process of movement skilfulness in terms of movement smoothness and velocity profile.     

Frequency-dependent modulation of rhythmic human jaw movements

Modulation of jaw movement patterns by alteration of the chewing rhythm was analyzed in nine subjects. Jaw movements were monitored by an electronic transducer system. The subjects were asked to chew gum either at voluntarily determined rates or at rates guided by a light flash that varied from 2 to 7 Hz at 1-Hz intervals. The results can be summarized as follows: Chewing was generally conducted at rates below 3 Hz when the rhythm was voluntarily determined. When the rhythm was guided, however, the maximum chewing rate could occasionally be raised up to 6 Hz; the duration of the chewing cycle was more closely related to changes in the duration of the opening and occlusion phases than to that of the closing phase; at chewing rates below 3 Hz, the maximum gape did not appreciably change with the chewing rhythm, while it decreased linearly at rates above 3 Hz; and at chewing rates below 3 Hz, the jaw opening velocity increased with speed of chewing, whereas it decreased or sometimes fluctuated over a wide range at rates above 3 Hz. It is concluded that, during normal mastication at rates below 3 Hz, chewing rhythm is altered by changing both the velocity of jaw opening and the duration of the occlusion phase.     

Impaired mastication modifies the dynamics of bolus formation

Mastication is a complex sensory-motor activity whereby a food product is transformed into a bolus. Consumers mainly perceive the sensory properties of the food during the intra-oral manipulation of the product. Consequently, the quality of the chewing process could have consequences on the perception of sensory properties and food choice. By focusing on meat products, this study aimed to analyze the influence of dental status on (i) dynamic adaptation of the chewing behavior (evaluated by electromyography) to the changes in texture during bolus formation and (ii) bolus properties (mechanical resistance and saliva incorporation) obtained from meat of different initial textures. Two groups of subjects (dentate subjects and denture wearers), known to present highly different chewing efficiency, were compared. For both groups, salivary flow rates were evaluated at rest and after stimulation by chewing (paraffin and meat). The salivary flow rates, assessed during chewing of a nonedible matrix (paraffin), were a good predictor of salivary flow rates induced by meat chewing for both groups of subjects. Salivary flow rates were not affected by the dental status. In contrast, the chewing behavior varied between groups. For denture wearers, the chewing pattern was strongly impaired and not adapted to the changes in meat structure during bolus formation. Denture wearers swallowed less fragmented boli than dentate subjects, but boli had a similar level of moisture for both groups of subjects.     

不同类型反[牙合]冠状面咀嚼模式分析

目的阐明不同类型反(牙合)冠状面咀嚼模式方法选取12-35岁109名不同类型反(牙合)和16-30岁22名正常(牙合)个体。根据冠状面切牙点的运动轨迹将咀嚼模式分为8种咀嚼型。反(牙合)患者按反(牙合)的前后向位置和横向位置分组,Mann-Whitney U 检验比较不同类型反(牙合)组与正常胎及各组之间各种咀嚼型发生频率的差异。结果所有反(牙合)组,正常咀嚼型发生频率明显小于正常(牙合)。后牙反(牙合)组,相对前牙反(牙合)组,反向型发生率高(P=0.002),正常型发生率小(P=0.001).当伴随下颌偏斜和或下颌前突,牙弓段反(牙合)时,后牙反(牙合)的反(牙合)侧或下颌偏斜的偏斜侧,反向及反向交叉型比对侧易发生。结论在冠状面上,后牙反(牙合)组比前牙反(牙合)组呈现出更多的异常咀嚼型,后牙反(牙合)可能是反向及反向交叉咀嚼型的促成因素,尤伴有下颌偏斜,下颌前突及牙弓段反(牙合)时更明显。