Relationship between depression and masticatory muscles function in a group of adolescents

Objective: The aim of the study is to determine association between depressive symptoms and the electrical activity of muscles in maximum voluntary clench in a group of young adults.

Methods: A total of 186 volunteers (Females = 98, Males = 88), with a mean age of 19 years, were recruited to the study. All participants took a questionnaire survey stating the level of depression (Beck’s scale), clinical examination, and instrumental diagnostics (EMG).

Results: Symptoms of mild or medium depression were found in 35 of the subjects (18.82%). Average electric potentials of the masticatory muscles in maximal voluntary clench were significantly higher among the subjects with depression symptoms in comparison with subjects without those symptoms (85.96 ± 10.25 vs 78.97 ± 15.32, p < . 0.05).

Discussion: An increase in the electrical potentials of masseter muscles in maximal voluntary clench was found in the group with depression symptoms. The study should be continued to confirm this finding.     

Sex differences in signs and symptoms from masticatory and other muscles in 19-year-old individuals

Pain and tenderness of masticatory muscles are often related to muscle tenderness elsewhere in the body. It has been shown that women are more prone to musculoskeletal disorders than men. We sought to determine whether sex differences of muscular symptoms were established by the age of 19. The subjects comprised 51 boys and girls who received a questionnaire regarding the function of their masticatory system, frequency of headache, and neck, shoulder and low back pain. Their masticatory system was examined, and neck and shoulders were palpated. For all variables in the questionnaire girls reported symptoms more often than the boys. Of the subjects 50% had tender chewing muscles upon palpation. Again the girls had the most. There was good correlation between reports of pain in one area as compared to others. The number of clinically tender neck and shoulder muscles correlated with the number of tender masticatory muscles. It was concluded that girls presented more muscular symptoms than boys.     

Anamnestic index severity and signs and symptoms of TMD

The aim of this study was to determine the frequency and to characterize the symptoms and clinical signs of temporomandibular disorders (TMD) related to each severity category of Fonseca's anamnestic index in a sample of Brazilian young adults (mean age 21.61+/-1.91 years, 87% females and 13% males), by the application of an anamnestic index proposed by Fonseca (1992) and by clinical examination considering mandibular range of motion and tenderness to palpation of stomatognathic system structures. A significant number of participants were classified with mild TMD (43.2%) and moderate TMD (34.8%). Pain frequency during mastication, temporomandibular joint (TMJ) pain, and TMJ sounds were shown to be good predictors of TMD severity. Neck pain, headache, difficulty during mouth opening and lateral deviation, and tenderness to palpation of masticatory sites and during protrusion accompanied the TMD severity but failed to demonstrate differences between moderate and severe groups, showing a poor ability to determine TMD severity progression. This study suggests that not only the frequency of signs and symptoms of TMD should be determined, but also symptom severity and its relationship to the presence of clinical signs in order to discriminate patients with real treatment needs in nonpatient samples.     

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.     

Evaluation of masticatory muscles of edentulous patients by computed tomography and electromyography

summary On account of its tissue resolution capacity, computed tomography (CT) is an excellent method for the examination and quantitative analysis of the masticatory muscles. The aim of the present study was to evaluate the influence of the long edentulous period by CT on the structure of the main masticatory muscles in 10 edentulous patients and to study their functioning by electromyography (EMG) in connection with the renewal of the dentures. CT scanning was performed before prosthodontic treatment and EMG recordings of the masseter and temporal muscles before treatment and 4 weeks and 6 months after insertion of the new dentures. The results suggest, however, that a long edentulous period is visible not only in the functioning of the masticatory muscles, in terms of decreased EMG activity, but also as decreased density of the muscles which implies muscle atrophy, as seen by CT in the masseter and medial pterygoid muscles.     

咬合检测材料对咀嚼肌表面肌电的影响

目的探讨不同咬合检测材料在牙尖交错位（ICP）紧咬状态下对咀嚼肌肌电水平的影响。方法筛选30名大学生志愿者,分别在空白对照、口内放入咬合纸、口内放入T-Scan咬合片、口内放人T-Scan咬合架及咬合片（加架咬合片）等四种状况下作ICP最大紧咬,使用Bio-pak肌电图仪分别记录每组双侧颞肌前份（TA）及咬肌（MM）的肌电水平,并对四组数据进行比较分析。结果（1）与对照组相比．咬合纸组、咬合片组、加架咬合片组的TA、MM肌电幅值均升高;除加架咬合片组右侧TA（P〉0．05）外,其他差异均有统计学意义（P〈0．05）。（2）咬合纸组、咬合片组、加架咬合片组两两间比较差异无统计学意义（P〉0．05）。（3）与对照组TA不对称指数相比,咬合纸组、加架咬合片组差异有统计学意义（P〈0．05）,而咬合片组则无统计学意义（P〉0．05）;与对照组的MM不对称指数相比,加架咬合片组不对称指数差异有统计学意义（P〈0．05）,咬合纸组、咬合片组则差异无统计学意义（P〉0．05）。（4）与咬合片组TA不对称指数相比,咬合纸组、加架咬合片组差异有统计学意义（P〈0．05）。结论（1）不同咬合检测材料对所检测咀嚼肌肌电均有影响;（2）与加架咬合片相比．单纯咬合片对所检MM的肌电影响更小,因此对咬合检测结果的干扰更小。     

A method for performing stimulation electromyography of the masticatory muscles in man]

A principal block scheme of an apparatus complex is suggested and a method for examination of masticatory muscle function is described. The method is based on electrostimulation of masticatory nerve followed by registration and analysis of the masticatory muscle action evoked potentials. The block scheme of the apparatus complex includes a universal electrostimulator ESU-2. Examinations of 30 healthy volunteers and 30 patients with unilateral fractures of the mandible helped define the major parameters of stimulation electromyography. The patients were treated by splints applied on the teeth with fixation on both jaws. By day 28 of the investigation the M-response amplitude dropped more than twofold and its length by 1.5 times as against the mean parameters in health.     

Effect of conventional TENS on pain and electromyographic activity of masticatory muscles in TMD patients

Temporomandibular disorders (TMD) are characterized by several signs and symptoms, such as pain and changes in the electrical activity of masticatory muscles. Considering that transcutaneous electrical nerve stimulation (TENS) is a resource indicated to promote analgesia, the objective of this study was to evaluate the effect of TENS on pain and electromyographic (EMG) activity of the jaw elevator muscles in TMD patients. This study evaluated 35 female volunteers: 19 TMD patients (mean age = 23.04 +/- 3.5) and 16 normal subjects (mean age = 23.3 +/- 3.0). Transcutaneous electrical nerve stimulation (conventional mode, 150 Hz) was applied once to each group for 45 minutes. Surface electromyography (gain of 100 times and 1 kHz sampling frequency) and the visual analogue scale (VAS) were applied before and immediately after TENS application. Both VAS data and root mean square (RMS) values were analyzed using Student's t-test. The TMD group, compared to the control group, showed higher EMG activity of the jaw elevator muscles at rest. No difference was observed between the groups regarding maximum voluntary clenching (MVC). In TMD patients, TENS reduced both pain and EMG activity of the anterior portion of the temporal muscle, increasing the activity of the masseter muscles during MVC. It is possible to conclude that a single TENS application is effective in pain reduction. However, it does not act homogeneously on the features of the electric activity of the muscles evaluated.     

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.     

Risk factors for signs and symptoms of TMD in a rural adult southeast Tanzanian population

The aim of this study was to determine some risk factors for signs and symptoms of temporomandibular disorders (TMD) in a rural adult population of Southeast Tanzania. Two hundred and eighteen adults aged 40+ years participated in the study. Joint clicking was significantly higher (p < 0.024) in the adults aged 60+ years than in the younger age group. Limited jaw opening was higher in females than males (chi2 = 46.4 on 2 df; p < 0.001), and there was a significant association between the type of toothbrush and limitation in jaw opening (chi2 = 156.6 on 4 df; p < 0.001). The results suggest that the use of miswaki (chewing sticks) and advanced age are risk factors for the high prevalence of signs and symptoms of TMD in this rural population. Further studies are recommended to control for other confounding factors such as socio-economic status.     

单侧后牙缺失对咀嚼肌肌电图的影响

目的:观察单侧后牙缺失对咀嚼肌肌电图的影响,从而探讨单侧后牙缺失在颞下颌关节(temporomandibular joint, TMJ)发病中的作用。方法:对40例单侧上颌后牙缺失患者组成的缺牙组和40例牙列完整的自愿者组成的对照组,进行肌电图检查。结果:缺牙组无论是松弛状态或紧咬时咀嚼肌的电位明显高于对照组(P<0.05),并且缺牙组紧咬时同名肌不对称性活动增加(P<0.05),其中对照组的咬肌肌电活动的对称性明显高于缺牙组(P<0.01),以上变化缺牙侧较非缺牙侧显著(P<0.05)。结论:单侧后牙缺失可以对咀嚼肌肌电图造成影响,可能是颞下颌关节疾病的发病原因之一。     

Relationship between signs and symptoms of mandibular dysfunction in adolescents

Abstract The relationship between signs and symptoms of mandibular dysfunction was studied in 285 17-yr-old adolescents living in the municipality of Skellefteå, Sweden. Of the sample 62% had either some sign or symptom of dysfunction, and there was a positive correlation (P<0.05) between the two indices used. Neither morphologic nor functional malocclusions were related to the anamnestic dysfunction index. Signs of mandibular dysfunction were significantly more frequently found in those with a feeling of fatigue in the jaw (P<0.001). TMJ sounds were related to palpation tenderness in the lateral pterygoid muscle and to impaired horizontal mobility of the mandible. The most frequent symptom related to various signs of mandibular dysfunction was feeling of fatigue in the jaws which suggests that this is an early symptom of muscular origin that should be observed more closely. The study supports the view that even a moderate reduction of mouth opening capacity may indicate mandibular dysfunction and we recommend that this variable be routinely recorded.     

Incidence of symptoms and signs of TMD following third molar surgery: a controlled, prospective study

Summary  The purpose of this prospective study was to investigate if third molar surgery is associated with the development of symptoms and signs of temporomandibular disorders (TMD) during a 6-month post-operative observation period using the Research Diagnostic Criteria for TMD (RDC/TMD) instrument. Seventy-two subjects eligible for third molar surgery under local anaesthesia (patients) were included. Patients were examined according to the RDC/TMD instrument at baseline, 1 week, 1 and 6 months after surgery. Twenty-five age- and sex-matched healthy non-operative control subjects (controls) were included and examined at baseline and at 6 months. In the patient group, we found: (i) reduced range of maximum jaw opening at one week after surgery ( P  < 0·001), (ii) increased characteristic pain intensity 1 week after surgery ( P  < 0·05), (iii) increased disability up to 1 month after surgery ( P  < 0·05), (iv) increased incidence of muscle pain on palpation up to 6 months after surgery ( P  < 0·05), (v) increased incidence of pain on palpation of the temporomandibular joint up to 6 months after surgery ( P  < 0·05) and (vi) increased incidence of painful TMD 6 months after surgery. But, when compared with untreated controls, subjects undergoing third molar surgery have a statistically insignificant increased incidence of TMD 6 months post-operatively.     

A 5-year follow-up of signs and symptoms of TMD and radiographic findings in the elderly

PURPOSE: The aim was to clarify the associations among subjective symptoms, clinical signs of temporomandibular disorders (TMD), and radiographic findings in the mandibular condyles of elderly people during a 5-year follow-up. MATERIALS AND METHODS: As part of a comprehensive medical survey of a random sample born in 1904, 1909, and 1914 (Helsinki Aging Study), 364 subjects living in Helsinki participated in the dental part of the examination during 1990 and 1991; after 5 years, 103 of these were reexamined. Comprehensive data on TMD were available for 94 subjects, and radiographic data were available for 88. TMD were assessed by Helkimo's anamnestic and clinical indices, and radiographic status was assessed by panoramic radiographs. RESULTS: During the 5-year follow-up, reported anamnestic symptoms of TMD for men changed little (9%); among women, the change from baseline was 42%. When the unchanged indices were compared, the gender difference was obvious. At baseline, 5% of the women, but no men, had severe signs (clinical index III) of TMD. At the end of follow-up, none showed severe signs. Comparison of radiographic findings between baseline and follow-up showed no differences, nor did differences appear in associations between radiographic findings and anamnestic or clinical indices. CONCLUSION: During the 5-year follow-up, signs and symptoms of TMD in these elderly individuals became milder or vanished. The radiographic status of the condyles remained stable, and no association appeared between radiographic findings and signs and symptoms of TMD.     

Anxiety and depression in adolescents and their relationship with signs and symptoms of temporomandibular disorders

PURPOSE: Several clinical studies suggest that psychologic factors may play an important role in the etiology and maintenance of temporomandibular disorder (TMD) signs and symptoms. The goal of this study was to verify the prevalence of anxiety and depression in adolescents, and their relationship with signs and symptoms of TMD. MATERIALS AND METHODS: The sample comprised 217 nonpatient adolescents between 12 and 18 years of age. The subjective symptoms and clinical signs of TMD were evaluated, respectively, using a self-report questionnaire and the Craniomandibular Index (CMI, which has 2 subscales), the Dysfunction Index, and the Palpation Index. The Hospital Anxiety and Depression Scale (HADS), a 14-item self-administered rating scale that was developed specifically to identify anxiety and depression in nonpsychiatric medical outpatients, assessed levels of anxiety and depression. RESULTS: In the total sample, anxiety and depression were present in 16.58% and 26.71% of subjects, respectively, including all levels of HADS. The results showed that there were positive correlations between CMI and Palpation Index and anxiety (HADSa) (P < .01) but not with depression (HADSd). An association between the number of TMD subjective symptoms and HADSa/HADSd was found (P < .01). CONCLUSION: Anxiety and depression, although of mild intensity, are common in adolescents. In this study both HADSa and HADSd were associated with an increasing number of TMD subjective symptoms. However, only anxiety was correlated with clinical signs of TMD (CMI), primarily muscle tenderness (Palpation Index).