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。     

Correlation of splint therapy outcome with the electromyography of masticatory muscles in temporomandibular disorder with myofascial pain

Abstract

Objectives. The aim of this study was to assess the effect of occlusal splint therapy on the electromyographic amplitude records (μV) of masticatory muscles in temporomandibular disorder (TMD) with myofascial pain and to detect a possible existence of a relationship between this effect and the treatment outcome. Materials and methods. Forty patients (23 females and 17 males) having TMD with myofascial pain were included in this study. They were randomly divided into two equal groups (20 of each). The first group (A) was treated by occlusal splints for 6 months while the second group (B) acted as a control. A clinical assessment and surface electromyography (EMG) for the masticatory muscles were performed at the beginning of the study, then 6 months later. The collected data were statistically analyzed using paired t-test. The differences were considered significant at p < 0.05. Results. The results showed that 85% of group A either completely recovered (35%) or clinically improved (50%) while only 20% of group B had a spontaneous improvement. In group A, the means of the electromyographic amplitude records (μV) of the monitored muscles have decreased after 6 months. However, the decrease was statistically insignificant (p > 0.05) in the patients (15%) who had no clinical changes. In group B, the means of the muscles' records (μV) in the left side slightly increased while those of the right side slightly decreased. These changes were statistically insignificant (p > 0.05). Conclusions. Occlusal splint could eliminate or improve the signs and symptoms of TMD patients with myofascial pain. It reduces the electromyographic amplitude records (μV) of the masticatory muscles. The splint therapy outcome has a correlation with the electromyographic amplitude changes of the masticatory muscles.     

髁状突纵形骨折及he夹板治疗时对翼外肌影响的光镜和电镜观察

目的：观察翼外肌下头和嚼肌在髁状突纵形骨折后及舱夹板治疗时的改变。方法：幼年小型猪18头，平均分3组，纵形骨折木治疗组，纵形骨折he夹板治疗组和正常对照组。建立髁状突纵形骨折和he夹板治疗模型。分别在实验后3周、6周和12周取材，进行光镜、电镜观察。结果：骨折后3周，骨折侧的翼外肌下头肌纤维间水肿较重，个别部位出现肌核增多和内移。he夹板治疗组翼外肌肌纤维间的水肿较轻。对侧翼外肌下头以及骨折后6周，12周以及双侧嚼肌肌纤维末见异常。电镜下纵形骨折后3周，可见骨折侧翼外肌下头肌纤维间隙增大，线粒体变圆、增大，数量增多，对侧翼外肌下头以及骨折后6周，12周双侧翼外肌下头以及双侧嚼肌肌纤维未见异常。纵形骨折he夹板治疗组3周可见翼外肌下头肌纤维线粒体轻度变圆、数量稍有增多。结论：幼年小型猪髁状突纵形骨折后，骨折侧的翼外肌下头肌纤维在形态有变化，但翼外肌具有较强的适应能力，he夹板治疗能减轻咀嚼肌的改变。     

髁状突纵形骨折及(牙合)夹板治疗时对翼外肌影响的光镜和电镜观察

目的:观察翼外肌下头和嚼肌在髁状突纵形骨折后及(牙合)夹板治疗时的改变.方法:幼年小型猪1 8头,平均分3组,纵形骨折未治疗组,纵形骨折(牙合)夹板治疗组和正常对照组.建立髁状突纵形骨折和(牙合)夹板治疗模型.分别在实验后3周、6周和12周取材,进行光镜、电镜观察.结果:骨折后3周,骨折侧的翼外肌下头肌纤维间水肿较重,个别部位出现肌核增多和内移.(牙合)夹板治疗组翼外肌肌纤维间的水肿较轻.对侧翼外肌下头以及骨折后6周,12周以及双侧嚼肌肌纤维未见异常.电镜下纵形骨折后3周,可见骨折侧翼外肌下头肌纤维间隙增大,线粒体变圆、增大,数量增多,对侧翼外肌下头以及骨折后6周,12周双侧翼外肌下头以及双侧嚼肌肌纤维未见异常.纵形骨折(牙合)夹板治疗组3周可见翼外肌下头肌纤维线粒体轻度变圆、数量稍有增多.结论:幼年小型猪髁状突纵形骨折后,骨折侧的翼外肌下头肌纤维在形态有变化,但翼外肌具有较强的适应能力,(牙合)夹板治疗能减轻咀嚼肌的改变.     

咬合恢复对偏侧咀嚼大鼠咀嚼肌影响的实验研究

目的：研究咬合恢复对偏侧咀嚼大鼠咀嚼肌的影响.方法：40只Wister大鼠随机分为4组,所有动物间断磨除有上、下颌磨牙牙冠至龈下,实验1组第3周、实验2组第9周停止磨牙,任其自行萌出,恢复咬合关系.对照组不停止牙冠磨除,饲养条件相同.实验1组磨除牙冠后10周末、实验2组磨除牙冠后16周末处死动物,取其双侧颞肌、咬肌进行光镜、电镜切片检查,结果与对照组对照.采用SPSS10.0软件进行统计学分析.结果：实验1组与对照1组双侧咀嚼肌受损情况有显著性差异（χ2=40,P＜0.01）.实验2组与对照2组双侧咀嚼肌受损情况无显著性差异（χ2=3.66,P＞0.05）.结论：早期咬合恢复,可恢复偏侧咀嚼大鼠咀嚼肌的损害.     

Variation of skin surface temperature over the masseter muscles in patients with myofascial pain following occlusal splint treatment

summary The skin surface temperature (SST) over the masseter muscles was measured in 19 patients suffering from myofascial pain (MP) and 20 controls who had no history of any craniomandibular disorder. Seven measurements with intervals of 2 weeks were carried out. MP patients received an occlusal stabilization appliance during their second visit as their only treatment. Clinical symptoms, including muscle sensitivity to palpation, jaw movement and general feeling were evaluated at each visit and compared to baseline. The results indicated that SST in the control group remained almost unchanged throughout the study. In the MP group, the mean temperature decreased during the study after initial treatment. Accordingly, there was a probability of 88.5% that the occlusal appliance treatment in the MP group would cause a decrease of SST over the masseter muscle. A significant relationship between clinical improvement and a decrease of SST was found in the MP group. Temperature recordings with certain limitations could be an objective assessory tool in diagnosis and follow-up of patients with myofascial pain.     

Soft occlusal splint therapy in the management of myofascial pain dysfunction syndrome: A follow-up study

Background and Objectives: Myofascial Pain Dysfunction Syndrome (MPDS) has been recognized as the most common, nontooth-related chronic orofacial pain condition that confronts dentists. A variety of therapies has been described in literature for its management. The present study is a prospective study carried out to evaluate the efficacy of occlusal splint therapy and compare it with pharmacotherapy (using analgesics and muscle relaxants) in the management of Myofascial Pain Dysfunction Syndrome. Materials and Methods: Forty patients in the age range of 17-55 years were included in the study and randomly assigned to one of two equally sized groups, A and B. Group A patients received a combination of muscle relaxants and analgesics while Group B patients received soft occlusal splint therapy. All the patients were evaluated for GPI, VAS, maximum comfortable mouth opening, TMJ clicking and tenderness during rest and movement as well as for the number of tender muscles at the time of diagnosis, after the 1 st week of initiation of therapy and every month for three months of follow-up. Results: There was a progressive decrease in GPI scores, number of tender muscles, TMJ clicking and tenderness with various jaw movements and significant improvement in mouth opening in patients on occlusal splint therapy during the follow-up period as compared to the pharmacotherapy group. Conclusion: Occlusal splint therapy has better long-term results in reducing the symptoms of MPDS. It has better patient compliance, fewer side effects, and is more cost-effective than pharmacotherapy; hence, it can be chosen for the treatment of patients with MPDS.     

Computerized analysis of occlusal contacts in bruxism patients treated with occlusal splint therapy

PURPOSE

Occlusal splints are commonly used to prevent tooth wear caused by bruxism. However, the effects of splints on occlusion are still unclear. Although it is rarely alluded in literature, splints can provoke severe occlusal alterations and other complications. This study was aimed to identify differences in the responses of individuals with bruxism and healthy individuals to a full-arch maxillary stabilization splint in terms of occlusal changes.

MATERIALS AND METHODS

Occlusal contacts in 20 (5 male, 15 female) bruxism patients and 20 (5 male, 15 female) controls with normal occlusion were evaluated before and after occlusal splint therapy. T-Scan III, a computerized occlusal analysis system, was used to simultaneously measure occlusion and disclusion times as well as left-right and anterior-posterior contact distributions before splint therapy and 3 months after therapy. Wilcoxon and Mann-Whitney U tests were used for statistical analyses (α=.05).

RESULTS

No differences were found in the posterior contact of bruxism patients before and after stabilization splint treatment. However, differences in posterior contact were observed between bruxists and normal individuals prior to treatment, and this difference disappeared following treatment.

CONCLUSION

The results of this study showed the use of a stabilization splint may not have an effect on occlusion. However, the area of posterior occlusal contact among bruxists was found to be greater than that of normal individuals. According to this study, the clinical use of splints may be harmless.     

Nocturnal electromyographic evaluation of myofascial pain dysfunction in patients undergoing occlusal splint therapy.

Twenty-five patients with symptoms of myofascial pain and abnormal jaw function were treated with use of a full arch maxillary occlusal splint. The level of nocturnal activity of the masseter muscle was monitored as were symptoms before, during, and after occlusal splint therapy. A decreased nocturnal EMG level during treatment was noted for 52% of the patients. A return to pretreatment EMG levels after removal of the splint was noticed in 92% of the patients; in 28% no change was shown and in 20%, an increase was shown in nocturnal EMG levels. The splint was most likely to reduce nocturnal EMG levels in patients with least severe symptoms.     

A novel vibratory stimulation-based splint for chronic and untreatable masticatory myofascial pain: A case-series

AimThis clinical report aimed to introduce a novel vibratory stimulation-based occlusal splint (VibS) for management of chronic and untreatable masticatory myofascial pain (MMFP).MethodsThis study was conducted on four chronic MMFP patients (mean age: 27.5 ± 5.56 years, females) who were diagnosed according to the research diagnostic criteria for temporomandibular disorders (RDC/TMD), and who were using stabilization splints for more than 6 months and still complained of pain above 40 mm in a 100-mm VAS scale. The included subjects utilized the active VibS and subsequently the inactive VibS during 30 days in each trial, separated by a wash-out period of at least 8 months. VAS pain levels were the only measured dependent variable, and were recorded before and after the use of active VibS and inactive VibS.ResultsAt baseline, mean VAS pain levels before using the active or inactive splint were 54.5 ± 19.8 mm and 44.0 ± 13.6 mm, respectively. After using the active VibS, mean pain level decreased by 77% (VASpos-pre = ?42.0 ± 30.3 mm). On the other hand, after using the inactive VibS, severe pain aggravation of 67% in magnitude was observed (VASpos-pre = +29.5 ± 21.5 mm).ConclusionThis case-series study demonstrated a good tendency of this novel VibS in chronic MMFP alleviation after a 4-week management period compared to a control inactive VibS.     

Evaluation of the effect of a stabilization splint on occlusal force in patients with masticatory muscle disorders

The purpose of this study was to evaluate the effect of stabilization splint therapy on occlusal force in patients with masticatory muscle disorders (MD). Six female patients with myalgia or myofascial pain participated in this study. The occlusal points and load on the dental arch in maximum clenching was measured using the computerized system with Dental Prescale(R) before and after the use of the splint. There were no significant changes in the number of occlusal points, mean occlusal pressure, and asymmetry in occlusal balance between before and after the use of the splint. However, there were significant differences in the extent of the area of occlusion and in the integrated occlusal loads. The integrated occlusal load converged to the normal level with the use of the splint. From the results of this study, it is suggested that the use of the stabilization splint has the effect of normalizing the occlusal force.     

Evaluation of the short-term effectiveness of education versus an occlusal splint for the treatment of myofascial pain of the jaw muscles

BackgroundThe authors conducted a clinical trial to compare the effectiveness of an education program with that of an occlusal splint in treating myofascial pain of the jaw muscles across a short period.MethodThe authors assigned 44 patients randomly to two treatment groups; 41 patients completed the study. The first group (four male, 19 female; mean [standard deviation {SD}] age, 31.4 [14.0] years) received information regarding the nature of temporomandibular disorder (TMD) and self-care measures, whereas the second group (five male, 13 female; mean [SD] age, 31.1 [8.8] years) received an occlusal splint. One of the authors evaluated each patient every three weeks during a three-month treatment period. Treatment outcomes included pain-free maximal mouth opening, spontaneous muscle pain, pain during chewing and headache.ResultsAfter three months, changes in spontaneous muscle pain differed significantly between the education and occlusal splint groups (P = .034; effect size = 0.33). Changes in pain-free maximal mouth opening did not differ significantly between groups (P = .528; effect size = 0.20). Changes of headache and pain on chewing did not differ significantly between groups (P ≥ .550, effect size ≤ 0.10).ConclusionsDuring a short period, education was slightly more effective than an occlusal splint delivered without education in reducing spontaneous muscle pain in patients with TMD. Pain-free mouth opening, headache and pain during chewing were not significantly different between the two treatments.     

咬合重建修复过程中咀嚼肌肌电图的变化

目的：探讨对垂直距离降低的患咬合重建修复过程中，咀嚼肌肌电图的变化。方法：对15例验垂直距离降低的患先用塑料验垫式可局部义齿过渡修复并恢复垂直距离，患适应后再按此高度永久修复。对比分析修复前、过渡修复一个月后以及永久修复一个月后嚼肌、颞肌前束和颞肌后束表面肌电图的变化。结果：①息止位时过渡修复及永久修复后嚼肌、颞肌前束和颞肌后束肌电幅值较术前均有明显减少趋势；②大力咬合位，过渡修复时颞肌后束肌电幅值较术前显减少，嚼肌和颞肌前束肌电无显改变。永久修复后嚼肌和颞肌前柬肌电较过渡修复时和术前有显提高，颢肌后柬肌电值较过渡修复时也显增加；③咀嚼时嚼肌和颞肌前柬肌电值在过渡修复及永久修复后逐步增加，永久修复后增加显。而颞肌后束肌电值无明显改变。结论：对垂直距离降低的病人升高垂直距离并进行咬合重建修复后，能显减少息止位嚼肌、颞肌前束和颞肌后束的紧张度，增强咀嚼肌大力咬合及咀嚼运动时的收缩能力。