重度磨耗伴牙列缺损的一次性咬合重建修复

目的探讨一次性咬合重建修复重度磨耗伴牙列缺损的可行性。方法对1例重度磨耗伴牙列缺损的低位咬合患者采用垫式可摘局部义齿行一次性咬合重建,治疗后1个月和3个月复诊,询问患者主观感受。治疗前、治疗后1个月和3个月时,用肌电图仪测咀嚼肌肌电活动,用花生米悬浊液比色法测咀嚼效率。结果患者咬合升高3.5mm。随访3个月,患者无不适,对义齿的美观和功能都满意。静息状态下咀嚼肌肌电活动较治疗前明显减弱,最大紧咬状态下变化不明显。治疗前花生米悬浊液比色法光密度值为0.436,治疗后1个月和3个月的光密度值为0.745和0.875,患者治疗后咀嚼效率较治疗前明显提高。结论一次性咬合重建可以尝试性修复重度磨耗伴牙列缺损。     

牙齿重度磨耗患者咀嚼肌肌电的实验研究

目的 :研究重度牙齿磨耗 (TW )患者咀嚼肌的肌电活动 ,探讨不同类型牙合磨耗患者咀嚼肌受损的肌电表现。方法 :以 15例中老年重度牙齿磨耗患者为研究对象 ,通过肌电图仪 (EMG)测试下颌姿势位和牙尖交错位最大紧咬时颞肌前束 (TA)、咬肌 (MM )、二腹肌前腹 (DA )的肌电幅值 ;并以 8例正常牙合患者的咀嚼肌肌电幅值作为对照。结果 :姿势位时 ,磨耗Ⅰ、Ⅱ、Ⅲ组患者TA、MM、DA的平均肌电幅值高于对照组 ,TA、MM的肌电幅值增高显著大于对照组 (P <0 .0 1) ;ICP最大紧咬时 ,Ⅰ、Ⅱ、Ⅲ组患者TA、MM、DA平均肌电幅值降低 ,MM、DA肌电幅值与对照组比较有显著性差异 (分别为P <0 .0 1,P <0 .0 5 )。结论 :牙齿磨耗患者有肌紧张存在 ,Ⅲ型磨耗导致的不均匀接触对咬肌的损伤较大     

牙列重度磨耗伴缺损的可摘局部义齿重建修复

目的：探讨应用可摘局部义齿一次性咬合重建修复牙列重度磨耗伴缺损的可行性.方法：对17例牙列重度磨耗伴缺损的患者采用（耠）垫式可摘局部义齿行一次性咬合重建,治疗后1个月、3个月和6个月复诊,调查患者主观感觉、咀嚼效果、义齿稳定性;以及是否有颞颌关节不适.结果：患者咬合升高1.5mm-2.5mm.随访6个月,患者无不适,咀嚼功能改善明显,对义齿的美观和功能都满意.结论：对于牙列重度磨耗伴缺损的病例可以尝试应用可摘局部义齿进行一次性咬合重建修复.     

咬合重建对牙齿重度磨耗患者咀嚼运动模式的影响

目的探讨咬合重建修复对不同类型的牙齿重度磨耗患者咀嚼运动模式的影响。方法选择29例牙齿重度磨耗进行咬合重建修复的患者,根据后牙咬合支持状态分成后牙支持完全组（试验Ⅰ组,15例）和后牙支持不全组（试验Ⅱ组,14例）,分别测量修复前、过渡修复1个月及永久修复1个月后咀嚼运动时嚼肌、颞肌前束和颞肌后束的表面肌电图,并选择15例正常人作为对照组,分析咀嚼周期、咀嚼运动活动期与间歇期比值及肌电积分值的变化。结果修复前,试验Ⅰ组和Ⅱ组患者的咀嚼周期与对照组之间无统计学差异（P>0.05）;试验Ⅱ组活动期与间歇期比值明显高于对照组,而颞肌前束的肌电积分值低于对照组（P<0.05）。过渡修复及永久修复后,试验Ⅰ组和Ⅱ组的咀嚼周期有逐步缩短的趋势。过渡修复时,Ⅰ组患者活动期与间歇期比值和肌电积分值较修复前均有下降（P<0.05）;Ⅱ组患者活动期与间歇期比值较修复前下降（P<0.05）,肌电积分值的变化则不明显（P>0.05）。永久修复后,Ⅰ组患者活动期与间歇期比值和肌电积分值较过渡修复时的变化均无统计学意义（P>0.05）;Ⅱ组患者活动期与间歇期比值较过渡修复时进一步下降,肌电积分值则明显提高（P<0.01）。结论咬合重建修复能明显改善重度磨耗患者咀嚼运动循环模式,提高咀嚼肌活动强度。     

固定义齿修复老年人重度磨耗的咀嚼效能分析

目的观察牙合重度磨耗的老年患者一次性升高咬合,固定修复后的咀嚼效能变化。方法17例患者采用吸光度法在修复前及修复后3、6个月分别进行咀嚼效能定量分析。结果牙合重度磨耗经修复治疗后,其咀嚼效能均高于修复前,且随着戴牙时间的延长,咀嚼效能亦逐渐提高。结论对牙合重度磨耗且修复要求较高的老年患者,可以在正确的颌位上一次性适当增加咬合高度。     

固定义齿修复老年人(牙合)重度磨耗的咀嚼效能分析

目的观察(牙合)重度磨耗的老年患者一次性升高咬合,固定修复后的咀嚼效能变化.方法17例患者采用吸光度法在修复前及修复后3、6个月分别进行咀嚼效能定量分析.结果(牙合)重度磨耗经修复治疗后,其咀嚼效能均高于修复前,且随着戴牙时间的延长,咀嚼效能亦逐渐提高.结论对(牙合)重度磨耗且修复要求较高的老年患者,可以在正确的颌位上一次性适当增加咬合高度.     

固定义齿修复老年人殆重度磨耗的咀嚼效能分析

目的 观察[牙合]重度磨耗的老年患者一次性升高咬合，固定修复后的咀嚼效能变化。方法 17例患者采用吸光度法在修复前及修复后3、6个月分别进行咀嚼效能定量分析。结果 [牙合]重度磨耗经修复治疗后，其咀嚼效能均高于修复前，且随着戴牙时间的延长，咀嚼效能亦逐渐提高。结论 对[牙合]重度磨耗且修复要求较高的老年患者，可以在正确的颌位上一次性适当增加咬合高度。     

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。     

肌位咬合板对颅颌功能紊乱者咀嚼肌肌电图的影响

目的：研究肌位咬合板对颅颌功能紊乱（ Ｃ Ｍ Ｄ）患者咀嚼肌肌电的影响,探讨其作用机理。方法：采用美国 Ｅ Ｍ２ 型肌电仪记录１０２ 例患者带咬合板前后的姿势位（ Ｍ Ｐ Ｐ）及牙尖交错位（ Ｉ Ｃ Ｐ）最大紧咬时的肌电变化。结果：（１）即刻戴入咬合板后颞肌前束（ Ｔ Ａ）与嚼肌（ Ｍ Ｍ）的 Ｍ Ｐ Ｐ高电位明显降低（ Ｐ＜ ０．０５）;治疗后不戴咬合板复查, Ｔ Ａ、颞肌后束（ Ｔ Ｐ）和 Ｍ Ｍ 肌紧张缓解。（２）戴咬合板紧咬双侧 Ｔ Ａ、 Ｔ Ｐ 和 Ｍ Ｍ 的肌电活动显著减小（ Ｐ＜ ０．０５）, Ｍ Ｍ 的肌电活动对称性明显提高（ Ｐ＜ ０．０５）,活动指数显著增加（ Ｐ＜０．０５）。结论：肌位咬合板能明显降低升颌肌最大紧咬的肌电活动,提高嚼肌的肌电活动对称性及活动指数。     

老年人牙列重度磨耗的固定义齿咬合重建修复

目的：探讨老年人牙列重度磨耗的固定义齿咬合重建修复的可行性，总结临床经验。方法：回顾性研究7例老年人牙列重度磨耗的固定义齿咬合重建患者临床资料，分析临床表现、诊疗特点，总结诊疗过程中注意事项。由一个典型病例介绍诊疗过程。结果：老年人牙列重度磨耗临床表现、并发症多样，[牙合]垫式活动义齿暂时性修复3个月后，单颌或双颌固定义齿咬合重建，修复12个整牙列，随访2～4年，患者满意度高，未出现再度磨耗，颞下颌关节稳定。结论：老年人牙列重度磨耗的固定义齿咬合重建修复可行，诊疗过程较长，中短期疗效肯定。     

咬合板高度对TMD患者咀嚼肌肌电的影响

目的:研究不同高度的咬合板对颞下颌关节紊乱病(TMD)患者颞肌前束、咬肌肌电的影响。方法:73例TMD患者随机分为3组,戴用不同高度咬合板使咬合距离分别增加3mm、5mm、7mm,比较分析戴板前和戴板后即刻测量的双侧颞肌前束(TA)和咬肌(MM)肌电电位。结果:在静息及紧咬状态下,戴用不同高度咬合板即刻测量的TA及MM肌电电位均明显低于戴板前的测量值(P<0.05);紧咬状态下5mm和7mm咬合板对MM肌电电位的降低程度显著高于3mm组。结论:咬合板是治疗肌功能紊乱的有效方法。高度为5mm和7mm的咬合板降低咀嚼肌肌电的能力较3mm咬合板更强。     

The immediate effects of a stabilization splint on the muscular symmetry in the masseter and anterior temporal muscles of patients with a craniomandibular disorder

In 36 myogenous craniomandibular disorder patients, the immediate effects of a stabilization splint on the symmetry in the activities of the masseter and anterior temporal muscles during submaximal clenching at five clenching levels were investigated electromyographically. After the adjustment of the splint necessary at the time of delivery, 20 splints remained free from occlusal interferences throughout the treatment period and thus needed no further adjustment. These splints caused an immediate improvement in masseter muscle symmetry at the time of delivery (p less than 0.01). However, 16 splints needed further adjustment for occlusal interferences at the first recall, 2 weeks after delivery of the splint. These splints resulted in a small but statistically significant worsening in masseter muscle symmetry at the 10% clenching level (p less than 0.01). No such response was found for temporal muscle activity. The immediate changes in masseter muscle activity suggest that muscular symmetry is an objective basis in the evaluation of the treatment provided.     

Influence of Different Centric Functions on Electromyographic Activity of Elevator Muscles

This study compares eight different occlusal centric functions with splint contact on different teeth in order to determine their influence on mandibular elevator electromyographic (EMG) activity.

Maxillary occlusal splints were built for eight subjects without craniomandibular dysfunction. Investigators divided each splint into three parts, in order to record different occlusal schemes in the same subject without varying the vertical dimension. EMG activity in the left masseter and anterior temporal muscles was registered during maximum voluntary clenching.

Results showed higher masseter activity with the splint than without, and anterior temporal activity was similar. There was a significant decrease of EMG activity with the anterior section of the splint. There were no significant differences between the remaining centric functions and clenching with the complete splint, except for the centric function with contralateral posterior contact, in which elevator activity was significantly reduced.

Results suggest that bilateral posterior occlusal stabilization is critical for maximum interocclusal force.     

Bite plates and stabilization splints in mandibular dysfunction. A clinical and electromyographic comparison

Twenty patients with mandibular dysfunction, all women, aged 17-41 years, were randomized for treatment with either a bite plate with a frontal plateau or a full-coverage stabilization splint. The occlusal appliances were used at night for 6 weeks to compare clinical and electromyographic effects (EMGs). Integrated EMGs were recorded bilaterally from the anterior and posterior parts of the temporal muscle and the masseter muscle in the rest position and during gentle and maximal biting before and after treatment without the appliances in situ. Initially recorded EMG activity in the temporal muscle was correlated to signs of dysfunction in the rest position. Compared with previously investigated healthy subjects, the patients had lower EMG activity in the anterior part of the temporal muscle and in the masseter muscle during maximal biting. Use of occlusal appliances at night for 6 weeks did not change the EMG activity in the rest position or during maximal biting. The clinical signs improved, significantly in the splint group. The subjective symptoms improved in both groups, significantly more in the splint group.     

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.     

Influence of Occlusal Splints on Bilateral Anterior Temporal EMG Activity during Swallowing of Saliva in Patients with Craniomandibular Dysfunction

A full-arch maxillary stabilization occlusal splint was made for each of 10 patients with craniomandibular dysfunction. These splints were divided into three sections (one anterior and two posterior). This procedure allowed variation in the anteroposterior centric localization of occlusal contacts, thus permitting the recording of the EMG effects produced by the different occlusal splint sections. The integrated EMG activity was recorded from the right and left anterior temporal muscles during swallowing of saliva in habitual occlusion and with the different occlusal splint sections inserted. EMG activity during swallowing of saliva was significantly lower with the different occlusal splints than in habitual occlusion. This supports the rationale for diurnal wear of the occlusal splint. No differences in EMG activity were found during swallowing of saliva when different sections of the occlusal splints were used. This fact points out the possibility for therapeutic use of different occlusal splints for improving swallowing function.     

Influence of group function and canine guidance on electromyographic activity of elevator muscles

A comparative EMG study was done between two types of occlusal guidances: group function and canine guidance. The purpose was to determine which of the two occlusal schemes causes a greater reduction in muscle activity and thereby a decrease in muscle tension in eccentric mandibular positions. Full-coverage occlusal splints were made for six test subjects with normal function of the stomatognathic system. Left- and right-side integrated EMG recordings were made of the masseter and temporal muscles during static (clenching) and dynamic (lateral excursion and clenching) maximal contractions. The results showed an EMG activity reduction of the elevator muscles with group function relative to their activity in centric occlusion. A more marked reduction was observed on the mediotrusive side, mainly in the temporal muscle. With canine guidance, the reduction in elevator muscle activity is much greater, more significant, and mainly in the temporal muscle of the mediotrusive side. The clinical implications of this study suggest the use of canine guidance in laterotrusion for therapy with full-coverage occlusal splints.     

The effects of an occlusal splint on the electromyographic activities of the temporal and masseter muscles during maximal clenching in patients with a habit of nocturnal bruxism and signs and symptoms of craniomandibular disorders

The effects of a full arch maxillary plane occlusal splint on the level of electromyographic (EMG) activity in the anterior temporal and masseter muscles during maximal clenching were studied in 31 patients with a habit of nocturnal bruxism and signs and symptoms of craniomandibular disorders, before and after occlusal splint therapy. The results showed, before treatment, that the occlusal splint changed significantly (in 71% of patients) the level of EMG activity during maximal clenching. However, these changes were not consistent and differed between patients and even, in some patients, between muscles. After long-term occlusal splint therapy and improvement of the signs and symptoms of craniomandibular disorders, the number of patients who had an identical level of EMG activity during maximal clenching in the intercuspal position and on the occlusal splint tended to increase. Moreover, in these patients the level of symmetry of action in pairs of muscles during maximal clenching was strong, and the splint did not change this level of symmetry.     

Response patterns of craniomandibular muscles with and without alterations in sensory feedback

1. Surface EMG recordings were made bilaterally from the anterior part of the temporal muscle, superficial masseter muscle, and the suprahyoid complex of muscles while tracking mandibular incisor movement in three planes. This was done in 20 normal subjects with 16 different responses. Some responses involved clenching whereas other responses occurred with actual mandibular movement. 2. Each muscle demonstrated a probability of recruitment dependent on the response that correlated with the intensity of recruitment. The higher the probability of recruitment, the greater the intensity of muscle activity. 3. The anterior temporal muscle demonstrated no statistically significant difference in any of the responses between the left and right muscles. The masseter muscle also demonstrated bilateral symmetry. 4. The anterior part of the temporal muscle was recruited in more than 60% of its trials (60% to 100%) in ipsilateral laterotrusion, retrusion, fast vertical raising, clenching on the ipsilateral or intercuspal position, and mastication. The temporal muscle was recruited in less than 60% of its trials in contralateral and incisor clenching, and less than 30% in contralateral laterotrusion, protrusion, and opening. 5. The superficial masseter muscle was recruited in more than 60% of its trials in protrusion, vertical raising, all clenches, and mastication. The masseter muscle was recruited less than 60% in retrusion, ipsilateral laterotrusion, and opening. 6. The suprahyoid group of muscles was recruited in more than 60% of its trials in protrusion, opening, and mastication. This group of muscles was recruited less than 60% of the time in clenching, lateral movements, and rapid vertical raising of the mandible. 7. Applying a maxillary splint to seven subjects significantly decreased the recruitment of the anterior temporal and masseter muscles during mastication. The splint also modified the use of the masseter muscle during protrusion so that it was less active, but increased its recruitment during contralateral clenching. The suprahyoid muscle group was unaffected by the maxillary splint. 8. These data support the concept that movement of the mandible from the intercuspal or rest position develops a coactivation pattern that will excite or inhibit a given muscle regardless of whether clenching with occlusal contacts or no occlusal contact is involved. 9. The data also demonstrate that the maxillary splint can alter the use of the jaw elevator muscles, predominantly in mastication.     

Influence of vertical dimension on masseter muscle electromyographic activity in patients with mandibular dysfunction

Occlusal splints were adjusted to different vertical heights and used to single out the influence of vertical dimension of occlusion in increments on BT-EMG activity of the masseter muscle in patients with mandibular dysfunction. The vertical dimension of least EMG activity was determined for each of 60 patients, who were randomly divided into three groups according to the vertical dimension at which the occlusal splint was adjusted: group No. 1, 1 mm from occlusal vertical dimension; group No. 2, mean vertical dimension, 4.25 mm; group No. 3, mean vertical dimension, 8.25 mm. Results showed a significant reduction of masseter BT-EMG activity (series A and B) at the end of the 3-week treatment period for patients in group Nos. 2 and 3 in comparison with group No. 1. Furthermore, the short-term use of occlusal splints with a vertical height that exceeded the so-called physiologic interocclusal distance did not result in an increase in masseter BT-EMG activity. This study suggests that an increase of vertical dimension of occlusion to or near the vertical dimension of least EMG activity by means of occlusal splints can be an effective way to obtain a reduction in masseteric muscle activity.