Acupuncture and Temporomandibular Disorders: A 3-Month Follow-up EMG Study

Comparative Efficacy of Non-Invasive Therapies in Temporomandibular Joint Dysfunction: A Systematic Review

Temporomandibular disorder (TMD) is a multifaceted disorder impacting the temporomandibular joint (TMJ), causing substantial discomfort and functional limitations. This systematic review aims to comprehensively assess the effectiveness of non-invasive treatment modalities for TMJ dysfunction, prioritizing a definitive protocol to ensure patient safety and enhance quality of life. Employing the PRISMA guidelines, we meticulously analyzed 20 studies from a pool of 1,417 articles sourced from databases such as PubMed, Google Scholar, ScienceDirect, and Medline. These studies underscore the multifarious nature of TMD and the varied responses to treatments such as physical therapy, laser therapy, ultrasound and electrical stimulation, splint therapy, injections, and arthrocentesis. Notably, the review highlights the paramount importance of precise diagnosis, often through surface electromyography, followed by a tailored treatment approach integrating manual therapy, counseling, and splint therapy. The systematic analysis revealed that while certain treatments such as transcutaneous electrical nerve stimulation and low-level laser therapy showed limited efficacy, combination therapies, especially those involving manual therapy, counseling, and splint therapy, demonstrated substantial improvement in reducing pain, depression, and anxiety. The findings advocate for a non-invasive, patient-centric approach, emphasizing education and symptom management before considering more invasive procedures such as injections and arthrocentesis. The review identifies the need for more comprehensive, longitudinal studies to establish a standardized, evidence-based treatment protocol for TMJ dysfunction, aiming to improve patient outcomes holistically.

Effects of short-term acupuncture treatment on occlusal force and mandibular movement in patients with deep-bite malocclusion

Background/purpose

Acupuncture is well known to be effective for pain relief and muscle relaxation, and hence it is feasible that acupuncture treatment could change the occlusal forces and mandibular movements in subjects with deep-bite malocclusion. The purpose of this research was to determine the distribution of occlusal force and the border movement of the mandible in patients with deep-bite malocclusion before and after acupuncture treatment.

Materials and methods

This study involved 17 volunteers with deep-bite malocclusion and aged 20-30 years. Before and after acupuncture treatment, the distribution of the occlusal-force percentage at each tooth was measured and the percentage biting force in the first molar area during maximal clenching was recorded. Additionally, the mandibular movements including the maximum mouth opening and maximum lateral border movement were also evaluated. All of the data were analyzed statistically using the Wilcoxon signed-rank test.

Results

The percentage biting force at the first molar differed significantly between before and after the acupuncture treatments (P = 0.017). However, no treatment effects were seen for the maximum mouth opening and the maximum lateral border movement. Conclusion: Although the mandibular border movements did not change significantly, this study has confirmed that acupuncture treatment may become an alternative choice on improving the occlusal force of deep-bite patients.

Alterations in the stomatognathic system due to amyotrophic lateral sclerosis

Objectives:

To compare the molar bite force, electromyographic activity, chewing efficiency and thickness of the masseter and temporalis muscles in individuals with amyotrophic lateral sclerosis (ALS) and healthy individuals.

Material and Methods:

Thirty individuals enrolled in the study were divided into the study group (with ALS, n=15) and control group (healthy individuals, n=15). Data regarding molar bite force (right and left), electromyographic activity (mandibular rest, right and left laterality, protrusion, and maximum voluntary contraction), chewing efficiency (habitual and non-habitual), and masticatory muscle thickness (rest and maximum voluntary contraction) were tabulated and subjected to statistical analysis (Student’s t-test, p≤0.05).

Results:

Comparisons between the groups demonstrated a statistically significant increase in the electromyographic activity of the right masseter (p=0.03) and left masseter (p=0.03) muscles during mandibular rest; left masseter (p=0.00), right temporalis (p=0.00), and left temporalis (p=0.03) muscles during protrusion; and right masseter (p=0.00), left masseter (p=0.00), and left temporalis (p=0.00) muscles during left laterality, in individuals with ALS as compared with healthy individuals. A statistically significant decrease was observed in the habitual chewing efficiency of the right masseter (p=0.00) and right temporalis (p=0.04) muscles in individuals with ALS. No statistically significant difference between the groups was found the masticatory muscle thickness and maximal molar bite force.

Conclusions:

ALS may lead to modifications in the activities of the stomatognathic system, including muscular hyperactivity and reduction in chewing efficiency; however, no change has been observed in the masticatory muscle thickness and molar bite force.

Effect of surgical treatment of mandibular fracture: electromyographic analysis, bite force, and mandibular mobility

This study aimed to examine individuals undergoing surgery for the treatment of the fractured mandibular angle, using bite force, mandibular mobility, and electromyographic (EMG) analysis in many different clinical conditions, after 2 months postoperatively. Bite force was recorded with a digital dynamometer, model IDDK. The EMG activity (Myosystem-Br1) included the analysis of the masseter and temporal muscles. Mandibular mobility was measured using a digital pachymeter. The subjects were divided into 3 groups: G1, mandibular angle fracture (n = 7); G2, condylar process fracture (n = 5); and G3, control (n = 12). Data were tabulated and submitted to statistical analysis using the repeated-measure test carried out over time and the Student's t-test (P < 0.05), using the Statistical Package for the Social Sciences software, version 19 (SPSS Inc, Chicago, IL). G1 and G2 had an increase in bite force. In G1, there was a regular decrease in the EMG activity in the second postoperative month. G2 presented an irregular pattern in EMG data during the period tested. Regarding the mandibular mobility, both groups obtained amplitude of all mandibular movements with a high percentage, when compared with control. A good functional recovery was achieved by the individuals who had a mandible angle fracture or condylar process fracture, after 2 postoperative months.

Functional analysis of the stomatognathic system in individuals infected with human immunodeficiency virus

PURPOSE

To understand the effects of HIV type 1 on the function of the masticatory muscles.

METHODS

Sixty individuals were selected from both genders, aged between 22 and 57years (mean 36.77±9.33years), and divided into two groups: Group HIVG, 30 individuals with HIV subtype 1, and Group CG, 30 healthy individuals (control group). The individuals were submitted to assessments of their masticatory muscle activity, biting strength and thickness of the masticatory muscles by means of electromyography, maximal molar bite force and ultrasound imaging, respectively. The resultant data were statistically analyzed by t-tests (p<0.05).

RESULTS

The HIVG normalized EMG data from a mandibular rest position, protrusion, right and left laterality movement of the jaw showed that HIVG presented a relative increase in EMG activity compared to the CG. The HIVG had a lower masticatory cycle ability while chewing Parafilm M®, Raisins and Peanuts when compared to CG. During rest conditions, the ultrasound images showed a greater average muscular thickness in the right and left temporal region compared to CG. Upon maximal voluntary contraction, an increased average thickness was seen in the temporalis muscles and left sternocleidomastoid muscle when compared to the CG.

CONCLUSION

Based on the results of this research, it can be concluded that individuals with acquired immunodeficiency syndrome showed muscular changes related to the stomatognathic system, especially concerning EMG activity and muscle thickness.

Could Acupuncture Be Useful in the Treatment of Temporomandibular Dysfunction?

In this study, the effects of acupuncture in comparison with flat occlusal plane appliance were evaluated in patient with myogenic temporomandibular dysfunction (TMD). The sample consisted of 40 women with TMD and unbalanced energy predominance of Yang Liver Ascension, selected using the Renying and Cunkou pulses, randomly divided into two groups: acupuncture and splint. The effect of treatments on the masseter and anterior temporal muscles was evaluated after 4 weeks of treatment, by means of electromyographic activity (root mean square) and pain pressure threshold. Pain intensity was measured using the visual analog scale, and range of mouth opening was evaluated using a millimeter ruler. All evaluations were performed at the beginning and end of the treatment. Visual analog scale score was reduced equally in the two groups (p < 0001), and the increase in range of mouth opening was significant in both groups. A significant difference was detected only in pain pressure threshold of the left masseter in the acupuncture group (p < 0.05). Only root mean square in the at rest position of the right temporal muscle diminished in the final stage of the splint group (p < 0.05). Both treatments reduced the pain intensity of myogenic TMD in the short term and may be considered strategies for control of chronic pain related to TMD.

Electromyographic analysis of masseter and temporal muscles, bite force, masticatory efficiency in medicated individuals with schizophrenia and mood disorders compared with healthy controls

This study aimed to comparatively analyse the electromyographic activity of the masseter and temporal muscles at rest and during mandible postural clinical conditions (right and left laterality, protrusion and maximum voluntary contraction), right and left maximum molar bite forces and the masticatory efficiency of individuals with schizophrenia or mood disorders - all medicated (medicated groups) compared with control group (healthy volunteers) via electromyography. Individuals were distributed into three groups: Group I (Schizophrenia - 20 individuals), Group II (mood disorders - 20 individuals) and Group III (Control - 40 individuals). Basically, the results were only statistically significant for the clinical mandible conditions and bite force. The most unsatisfactory results were observed in the medicated groups in relation to the control group. The group with mood disorders obtained the most unsatisfactory results compared with the group with schizophrenia. It was suggested by these observations that the association of mood disorders and schizophrenia with medication has negatively affected the stomatognathic system in relation to controls when the electromyography and bite force were used for the analysis.

Clinical effectiveness of laser acupuncture in the treatment of temporomandibular joint disorder

BACKGROUND/PURPOSE

Temporomandibular joint disorder (TMD) is a general term for diseases of the temporomandibular joint and orofacial muscles. In this study, we tested whether laser acupuncture was effective for the treatment of TMD.

METHODS

Twenty patients with TMD were treated with diode K-Laser (wavelength 800 nm, energy density 100.5 J/cm(2)) once a week at four acupuncture points including three standard ipsilateral local points (ST6, ST7, Ashi point) and one contralateral distal point (LI4). A 10-cm visual analogue scale (0 no pain and 10 the most severe pain) was used for measuring the pain intensity before and after the treatment.

RESULTS

Seventeen out of 20 patients (85%) showed various degrees of pain relief after laser acupuncture treatment. The average pain score was 6.3 ± 1.6 before treatment and 2.5 ± 2.2 after treatment. Significant pain relief after laser acupuncture treatment was achieved (p = 0.0003, Wilcoxon signed rank test). The 17 patients showed an average pain relief of 63 ± 31%. There were six patients who showed no TMD symptoms after an average of four treatments of laser acupuncture. The other 11 patients showed partial relief of TMD symptoms after treatment. Although the pain was still present, it was less and was acceptable. No side effects were reported in any patients during or after laser acupuncture treatments.

CONCLUSION

Laser acupuncture may be an alternative treatment modality for TMD because it is non-invasive, results in partial or total relief of pain, and has no side effects.

Effects of trigger point acupuncture treatment on temporomandibular disorders: a preliminary randomized clinical trial

We compared the effects of trigger point acupuncture with that of sham acupuncture treatments on pain and oral function in patients with temporomandibular disorders (TMDs). This 10-week study included 16 volunteers from an acupuncture school with complaints of chronic temporomandibular joint myofascial pain for at least 6 months. The participants were randomized to one of two groups, each receiving five acupuncture treatment sessions. The trigger point acupuncture group received treatment at trigger points for the same muscle, while the other acupuncture group received sham treatment on the trigger points. Outcome measures were pain intensity (visual analogue scale) and oral function (maximal mouth opening). After treatment, pain intensity was less in the trigger point acupuncture group than in the sham treatment group, but oral function remained unchanged in both groups. Pain intensity decreased significantly between pretreatment and 5 weeks after trigger point (p<0.001) and sham acupunctures (p<0.050). Group comparison using the area under the curve demonstrated a significant difference between groups (p=0.0152). Compared with sham acupuncture therapy, trigger point acupuncture therapy may be more effective for chronic temporomandibular joint myofascial pain.

Acupuntura como recurso terapêutico na dor e na gravidade da desordem temporomandibular

Este estudo avaliou o efeito da acupuntura no nível de dor e gravidade da Desordem Temporomandibular (DTM). Participaram dele 40 mulheres entre 20 e 40 anos com DTM diagnosticada pelo Research Diagnostic Criteria (RDC/TMD). A dor foi avaliada pela escala visual analógica e a gravidade da desordem pelos Índices de Disfunção Craniomandibular e de Fonseca. As 20 primeiras participantes foram submetidas a acupuntura duas vezes na semana por cinco semanas ininterruptas e, após o período, foram reavaliadas. Os dados destas participantes constituíram os resultados para o grupo acupuntura. As demais voluntárias receberam o tratamento após o primeiro grupo e seus dados, coletados no início e após cinco semanas sem tratamento, foram utilizados para controle. Na análise estatística foram levados em conta os testes de Wilcoxon para o nível de dor e Índice Craniomandibular e Teste t de Student para o Índice de Fonseca, com nível de significância de 5%. Houve redução significante no nível de dor (p=0,000) e na gravidade da DTM pelos Índices Craniomandibular (p=0,004) e de Fonseca (p=0,000) após o tratamento. O grupo controle não apresentou melhora. A efetividade da acupuntura foi demonstrada pela melhora no nível da dor e na gravidade da DTM.

Does acupuncture needling induce analgesic effects comparable to diffuse noxious inhibitory controls?

Diffuse noxious inhibitory control (DNIC) is described as one possible mechanism of acupuncture analgesia. This study investigated the analgesic effect of acupuncture without stimulation compared to nonpenetrating sham acupuncture (NPSA) and cold-pressor-induced DNIC. Forty-five subjects received each of the three interventions in a randomized order. The analgesic effect was measured using pressure algometry at the second toe before and after each of the interventions. Pressure pain detection threshold (PPDT) rose from 299 kPa (SD 112 kPa) to 364 kPa (SD 144), 353 kPa (SD 135), and 467 kPa (SD 168) after acupuncture, NPSA, and DNIC test, respectively. There was no statistically significant difference between acupuncture and NPSA at any time, but a significantly higher increase of PPDT in the DNIC test compared to acupuncture and NPSA. PPDT decreased after the DNIC test, whereas it remained stable after acupuncture and NPSA. Acupuncture needling at low pain stimulus intensity showed a small analgesic effect which did not significantly differ from placebo response and was significantly less than a DNIC-like effect of a painful noninvasive stimulus.

Acupuncture for treating temporomandibular joint disorders: a systematic review and meta-analysis of randomized, sham-controlled trials

OBJECTIVE

The aim of this article was to assess the clinical evidence for or against acupuncture and acupuncture-like therapies as treatments for temporomandibular joint disorder (TMD).

DATA

This systematic review includes randomized clinical trials (RCTs) of acupuncture as a treatment for TMD compared to sham acupuncture. The search terms were selected according to medical subject heading (MeSH).

SOURCES

Systematic searches were conducted in 13 electronic databases up to July 2010; Medline, PubMed, The Cochrane Library 2010 (Issue 7), CINAHL, EMBASE, seven Korean Medical Databases and a Chinese Medical Database.

STUDY SELECTION

All parallel or cross-over RCTs of acupuncture for TMD were searched without language restrictions. Studies in which no clinical data and complex interventions were excluded. Finally, total of 7 RCTs met our inclusion criteria.

CONCLUSIONS

In conclusion, our systematic review and meta-analysis demonstrate that the evidence for acupuncture as a symptomatic treatment of TMD is limited. Further rigorous studies are, however, required to establish beyond doubt whether acupuncture has therapeutic value for this indication.