The possible role of enkephalin in the mechanism of acupuncture analgesia in man

Temporomandibular disorders: improving outcomes using a multidisciplinary approach

Patients with temporomandibular disorders (TMD) can become very complex. This article aims to highlight the importance of the multimodal and multidisciplinary approach in this type of patients to improve clinical outcomes. At present we have innumerable techniques and tools to approach this type of patients from a biopsychosocial model where active and adaptive type treatments are fundamental. There are various health professions that have competence in the treatment of TMD, however, although in the most complex cases should be treated simultaneously, still too many patients receive unique treatments and only from one point of view. This review exposes the treatments available from a clinical-scientific perspective and also emphasizes the importance of working in specialized units with those professionals who have competencies on the different conditions that may occur.

Management of pain in patients with temporomandibular disorder (TMD): challenges and solutions

Thanks to advances in neuroscience, biopsychosocial models for diagnostics and treatment (including physical, psychological, and pharmacological therapies) currently have more clinical support and scientific growth. At present, a conservative treatment approach prevails over surgery, given it is less aggressive and usually results in satisfactory clinical outcomes in mild–moderate temporomandibular disorder (TMD). The aim of this review is to evaluate the recent evidence, identify challenges, and propose solutions from a clinical point of view for patients with craniofacial pain and TMD. The treatment we propose is structured in a multi-modal approach based on a biobehavioral approach that includes medical, physiotherapeutic, psychological, and dental treatments. We also propose a new biobehavioral model regarding pain perception and motor behavior for the diagnosis and treatment of patients with painful TMD.

Acupuncture therapy in the management of the clinical outcomes for temporomandibular disorders: A PRISMA-compliant meta-analysis

PURPOSE

The purpose of this study was to evaluate conventional acupuncture therapy in the management of clinical outcomes for temporomandibular disorders (TMD) in adults.

METHODS

The electronic databases PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and Clinical Trails.gov were searched for reports published until March 31, 2016.

RESULTS

Nine eligible studies from 8 publications involving 231 patients were included in the meta-analysis. A comparison of the main outcome of visual analog scale (VAS) values of pain between the acupuncture group and control group showed a significant decrease (MD = -0.98, 95% CI [-1.62, -0.34], I=54%, P = 0.003) in the VAS following acupuncture treatment. However, subgroup analysis according to the type of sham control group indicated that there were significant differences in the results when sham acupuncture was used as the control group (MD = -1.54, 95% CI [-2.63, -0.45], I=58%, P = 0.006) as well as when sham laser treatment was used as the control group (MD = -1.29, 95% CI [-2.32, -0.27], I = 0%, P = 0.01). However, there was no significant difference when the splint treatment group was used as the control group (MD = -0.09, 95% CI [-0.69, 0.50], I = 0%, P = 0.76). Subgroup analyses of VAS for pain by the classification of diseases indicated that the myogenous TMD subgroup demonstrated a significant difference (MD = -1.49, 95% CI [-2.45, -0.53], I = 47%, P = 0.002), and TMD showed no statistically significant difference (MD = -0.42, 95% CI [-1.14, 0.30], I = 46%, P = 0.25). Subgroup analysis according to whether the subgroup penetrated the skin showed that nonpenetrating sham acupuncture as the control group showed a significant difference (MD = -1.56, 95% CI [-2.70, -0.41], I = 58%, P = 0.008) compared with the conventional acupuncture as the treatment modality, while penetrating sham acupuncture as the control group showed no significant difference (MD = -1.29, 95% CI [-3.40, 0.82], I = not applicable, P = 0.23). No publication bias was observed considering the symmetry of the funnel plots.

CONCLUSIONS

Our results indicate that conventional acupuncture therapy is effective in reducing the degree of pain in patients with TMD, especially those with myofascial pain symptoms.

Needling therapy for myofascial pain: recommended technique with multiple rapid needle insertion

Myofascial trigger point (MTrP) is a major cause of muscle pain, characterized with a hyperirritable spot due to accumulation of sensitized nociceptors in skeletal muscle fibers. Many needling therapy techniques for MTrP inactivation exist. Based on prior human and animal studies, multiple insertions can almost completely eliminate the MTrP pain forthwith. It is an attempt to stimulate many sensitive loci (nociceptors) in the MTrP region to induce sharp pain, referred pain or local twitch response. Suggested mechanisms of needling analgesia include effects related to immune, hormonal or nervous system. Compared to slow-acting biochemical effects involving immune or hormonal system, neurological effects can act faster to provide immediate and complete pain relief. Most likely mechanism of multiple needle insertion therapy for MTrP inactivation is to encounter sensitive nociceptors with the high-pressure stimulation of a sharp needle tip to activate a descending pain inhibitory system. This technique is strongly recommended for myofasical pain therapy in order to resume patient's normal life rapidly, thus saving medical and social resources.

Probable mechanisms of needling therapies for myofascial pain control

Myofascial pain syndrome (MPS) has been defined as a regional pain syndrome characterized by muscle pain caused by myofascial trigger points (MTrPs) clinically. MTrP is defined as the hyperirritable spot in a palpable taut band of skeletal muscle fibers. Appropriate treatment to MTrPs can effectively relieve the clinical pain of MPS. Needling therapies, such as MTrP injection, dry needling, or acupuncture (AcP) can effectively eliminate pain immediately. AcP is probably the first reported technique in treating MPS patients with dry needling based on the Traditional Chinese Medicine (TCM) theory. The possible mechanism of AcP analgesia were studied and published in recent decades. The analgesic effect of AcP is hypothesized to be related to immune, hormonal, and nervous systems. Compared to slow-acting hormonal system, nervous system acts in a faster manner. Given these complexities, AcP analgesia cannot be explained by any single mechanism. There are several principles for selection of acupoints based on the TCM principles: “Ah-Shi” point, proximal or remote acupoints on the meridian, and extra-meridian acupoints. Correlations between acupoints and MTrPs are discussed. Some clinical and animal studies of remote AcP for MTrPs and the possible mechanisms of remote effectiveness are reviewed and discussed.

EFFECTS OF MYOFASCIAL–MERIDIAN STIMULATION THERAPY (MMST) ON SHOULDER PAIN

Fifty patients with shoulder pain were classified into two groups according to the type of pain: a capsular-pattern group (N = 22) and a non-capsular-pattern group (N = 28). Both groups received myofascial-meridian stimulation therapy four times in two weeks. After therapy, the pain level was significantly lower in the capsular-pattern than in the non-capsular-pattern group. The capsular-pattern group showed a nonsignificant trend toward greater range of motion than the non-capsular-pattern group. These data suggest that myofascial-meridian stimulation therapy might be useful as a new treatment to reduce pain and increase range of motion in patients with shoulder pain.