Evaluating the Efficacy of Warm Acupuncture and Electroacupuncture in Temporomandibular Disorder: A Narrative Review

Article information

Perspect Integr Med. 2025;4(2):87-95

Publication date (electronic) : 2025 June 30

doi : https://doi.org/10.56986/pim.2025.06.003

Lisa Dal Pozzo^1,, Secondo Scarsella², Maria Abad Arranz³

¹Tianjin University of Traditional Chinese Medicine, School of Integrative Medicine, Jinghai, China

²Maxillofacial Surgery Unit, San Salvatore Hospital, L’Aquila, and Nanjing University of Chinese Medicine, Jiangsu, China

³Italian Academy of Chinese Medicine, L’Aquila, Italy

^*Corresponding author: Lisa Dal Pozzo, Tianjin University of Traditional Chinese Medicine, School of Integrative Medicine, No. 10, Poyang Hu Road, Tuanbo New Town, Jinghai, Tianjin Province, China, Email: liz90pd@hotmail.it

Received 2025 April 30; Revised 2025 May 29; Accepted 2025 June 3.

Abstract

Visual abstract

Introduction

Temporomandibular joint disorder (TMD) refers to a group of painful conditions which affect the temporomandibular joint (TMJ), and it comprises several components with distinct roles: the ovoid condylar process with 2 condyles, the temporal bone, and the articular disk that enables both hinging and gliding. A fibrous capsule surrounds the joint and anchors it via external and internal ligaments, including the collateral, sphenomandibular, and stylomandibular ligaments. Masticatory muscles support the TMJ by facilitating jaw movements such as abduction and adduction, and they play a key, though not exclusive, role in TMD onset [1]. TMJ pathologies are diverse, with symptoms like chronic pain, jaw clenching, myalgia, headache, and arthralgia. TMD is divided into 4 subtypes: muscle pain, joint pain, TMD-related headache, and joint disorders. Myalgia, affecting 80% of TMD patients, involves the masticatory muscles and can radiate to the ears, eyes, or teeth [2]. Arthralgia is less common and often coexists with muscle pain. TMD-related headaches stem from masticatory system overuse and are diagnosed based on pain in the temple region triggered by jaw movements, positive physical examination, and a history of similar headaches. Joint disorders are diagnosed by disc displacement, painful joint sounds, and magnetic resonance imaging evidence. Additional joint-related signs include bone/cartilage loss, crepitus, and computed tomography-confirmed abnormalities [2].

Pain is the main reason patients seek care. Nonsteroidal anti-inflammatory drugs (NSAIDs) (ketorolac, naproxen, ibuprofen) are first-line for mild to moderate TMD associated pain. Opioids may be used for moderate to severe pain or in patients sensitive to NSAIDs [3]. Oral options include oxycodone, codeine, hydromorphone and a transdermal option is the fentanyl patch. Intra-articular morphine can raise pain thresholds in severe cases [4]. Elderly or sensitive individuals may experience adverse effects (e.g., nausea, dizziness) to intra-articular morphine, especially if the patient is taking benzodiazepines or consuming alcohol. Intra-articular corticosteroids show promise, particularly in juvenile idiopathic arthritis [5]; methylprednisolone has improved pain and mouth-opening [6]. When muscle involvement predominates, muscle relaxants (cyclobenzaprine, methocarbamol, metaxalone) are used. Given TMD’s link to insomnia, anxiety, and depression, antidepressants like citalopram and especially amitriptyline are helpful [7]. Selective serotonin reuptake inhibitors may help but can worsen bruxism, notably in women and children, so prescriptions should be individualized [8]. Anticonvulsants like intramuscular magnesium sulfate (an N-methyl-D-aspartate receptor antagonist) reduce calcium influx and inflammation [9]. Gabapentin, targeting gamma-aminobutyric acid receptors, is also used despite its unclear mechanism of action [10]. Benzodiazepines (e.g., clonazepam) have shown promise in a pilot study [11], though long-term use carries risks. A comparative study determined that both opioids and benzodiazepines improved levels of pain and mood, but higher benzodiazepine doses worsened outcomes, and higher opioid doses increased disability [12].

Non-pharmacological options include photobiomodulation, manual therapy, craniocervical techniques, self-massage, therapeutic exercise, splinting, occlusal appliances, post-isometric relaxation, myofascial release, and acupuncture, which have been used by Chinese populations over many years, support the efficacy of these approaches. A single-blind randomized controlled trial on TMD reported that acupuncture was superior to sham acupuncture in reducing pain intensity, with more lasting effects over time [13]. A systematic review published in 2010, involving 808 patients, reported improvements in pain tolerance, tenderness, and muscle mobility [14]. In addition, an audit published in 2006, based on case reports submitted by certified dentists, supported the benefits of acupuncture in reducing pain, particularly with points located near the TMJ [15].

Acupuncture and electroacupuncture (EA) are increasingly used in dentistry and oral surgery for postoperative and TMD-related pain [16,17]. In a study by Nambi et al [18] EA at acupoints BL10, GB2, GB21, ST7, ST6, ST5, SI19, and SJ17 was evaluated alongside standard physiotherapy. Most acupoints targeted the TMJ region, with 2 on the neck. Outcome measures included pain levels, frequency, threshold, mouth opening, disability, and quality of life, assessed via graded and the visual analog scale (VAS). The EA group showed significantly better improvements than the sham EA group receiving standard therapy. EA, a TCM-based technique, enhances acupuncture through the application of low- or high-frequency electrical stimulation across the needles. It has shown superior efficacy in pain relief compared with standard acupuncture [19]. Multiple mechanisms contribute to its effects: peripherally (via opioid receptor activation and endogenous opioid-like molecules); at the spinal level (through stimulation-induced release of serotonin, glutamate, norepinephrine, and opioids); and supraspinally (by engaging brain regions like the locus coeruleus, arcuate nucleus, nucleus accumbens, amygdala, and septal area through endogenous endomorphins) [20]. Recent studies have also highlighted how specific acupoint stimulation can modulate nociceptive signaling via well-defined neural circuits [21]. For example, stimulation of acupoints such as Zusanli (ST36) influences pain transmission at the level of dorsal root ganglia and spinal dorsal horn, and can induce descending inhibition through the periaqueductal gray, rostral ventromedial medulla, and locus coeruleus [21]. Acupuncture has also been shown to affect thalamic subregions involved in the sensory-discriminative and affective-cognitive dimensions of pain, as well as cortical structures such as the anterior cingulate cortex and prefrontal cortex [21]. These central mechanisms help explain how acupuncture regulates both physical pain and associated emotional responses. Furthermore, involvement of the limbic and reward systems including the nucleus accumbens and lateral hypothalamus suggests that acupuncture may activate intrinsic reward circuits, contributing to the analgesic and anxiolytic benefits observed in clinical practice [21]. Acupuncture has gained recognition in Western medicine for managing various pain syndromes. For TMD, the study reports benefits including pain reduction, improved jaw mobility, and speech, and enhanced quality of life [21].

Material and Methods

This narrative review was based on literature retrieved from English language and Chinese databases (PubMed, CNKI, Wanfang Data, and VIP) using the keywords “TMD,” “temporomandibular disorder,” “acupuncture,” and their Chinese equivalents. A screening process was applied to identify open-access clinical trials comparing acupuncture with a control (e.g., Western medicine, physiotherapy, alternative acupuncture). Only two-arm studies with ≥ 30 patients per group were included. The selection process is shown in the Preferred Reporting Items for Systematic reviews and Meta-Analyses flow diagram (Figure 1).

Figure 1

Preferred reporting items for systematic reviews and meta-analyses flowchart of study selection.

Pain in Traditional Chinese Medicine

Recent studies have evaluated the efficacy of traditional Chinese medicine (TCM)-based treatments for pain management across various conditions [22–29]. In a study by Du et al [22], a randomized controlled trial (RCT) involving 90 rheumatoid arthritis (RA) patients was conducted to assess the clinical effect of Huayu Qiangshen Tongbi (HQT) decoction, in combination with methotrexate. The treatment group (n = 37) received methotrexate and HQT, while the control group (n = 32) received methotrexate and leflunomide. The HQT group showed significantly greater improvements in biochemical markers and pain-related outcomes, including joint pain, swelling, and quality of life measures compared with the control group [22]. Xuefu Zhuyu decoction has been reported to alleviate various pain conditions, including neuralgia, lumbago, muscle pain, headache, and chest pain [23,24]. In the context of acupuncture, analysis of clinical reports, retrieved from the databases, identified the 15 most frequently used acupoints for treating stasis-related headaches: GB20, EX-HN5, GV20, LI4, GB8, LR3, SP10, ST8, BL17, SJ5, SP6, GB41, ST36, SI3, and LU7. Among these, Gallbladder meridian points accounted for 82.8%, with a predominance for Yang meridian involvement [25]. Specific acupoints, such as EX-HN5, have been associated with promoting blood flow [26], while SP10 has been linked to stimulation of blood circulation [27]. BL17 has demonstrated effects on thromboxane B2 levels [28], and GB20 has been used for its analgesic properties in clinical pain management [29].

In a study examining dysmenorrhea associated with cold accumulation and Qi stagnation, 60 patients were randomly assigned to receive either herbal point stimulation or oral diclofenac (75 mg daily) for 3 menstrual cycles [30]. The herbal group was treated with a ginger-based paste containing multiple herbs including Angelica sinensis, Ligusticum chuanxiong, Artemisia argyi, Corydalis yanhusuo, Asarum, Evodia rutaecarpa, Cinnamomum cassia, and Syzygium aromaticum applied at CV4, EX-CA1, BL32, and SP6 for 6–8 hours per day over 5 days preceding menstruation. While both groups experienced symptom improvement, the herbal group demonstrated superior short- and long-term effects (p < 0.05) [30]. CV4 has been widely used in the treatment of gynecological pain conditions [31], and BL32 has shown clinical relevance in treating primary dysmenorrhea [27,32], with enhanced effects when used in combination with moxibustion [33].

TCM Perspective on TMD

TMD is a multifactorial pain condition often involving muscular and connective tissue dysfunction in the TMJ region. An increasing number of studies highlight the contribution of myofascial components in its pathogenesis. Massage therapy has been shown to relieve TMD symptoms and improve psychological well-being [34].

Recent anatomical studies have explored the relationship between fascial structures and symptom distribution in TMD. The anterior superficial and lateral fascial chains have been noted for their anatomical parallels with known myofascial pain patterns affecting the head, neck, and shoulders [35,36]. These findings support a broader therapeutic approach that considers interconnected regions beyond the immediate TMJ area.

Fascia has been described as a critical structure linking muscles, tendons, and joints, including the TMJ, and its role in maintaining structural coordination and energy transmission has been noted in multiple sources [37]. Dysfunctions within these connective tissues are associated with pain, restricted movement, and mechanical imbalance in TMD patients [38].

Historical texts such as the Synopsis of the Golden Chamber have described conditions characterized by joint and muscular pain, attributed to complex interactions of external and internal influences [39]. In addition, classical descriptions have emphasized the importance of tendons in the development and transmission of pain, particularly in disorders involving joint movement [40].

1. Warm acupuncture in TCM treatment of TMD

Warm acupuncture combines acupuncture with moxibustion by attaching burning moxa to needle handles, delivering heat to stimulate meridians [41]. Clinical studies have demonstrated its efficacy in treating pain conditions such as chronic nonspecific low back pain [42], shoulder periarthritis [43], knee osteoarthritis [44], and cervical radiculopathy [45].

In a study by Feng et al [46], patients with TMD exhibiting cold-wind syndrome, had warm acupuncture applied at ST7, ST6, GB2, GB3, LI4, and points near the zygomatic bone, alongside fumigation therapy with warm herbal sachets. This combined treatment showed greater improvement in jaw mobility and pain reduction compared with treatment using topical diclofenac [46].

In a study by Liu et al [47], Ashi-point warm acupuncture was compared with a Western treatment regimen including diclofenac and glucosamine (n = 70 TMD patients). While initial response rates favored the drug group (87.5% vs. 84.8%, p > 0.05), warm acupuncture demonstrated significantly better long-term outcomes at 3 and 6 months in terms of joint movement, noise, and tenderness [47]. These results support previous trials which reported enhanced efficacy when warm acupuncture was combined with magnetic therapy (96.9% vs. 84.6%) [48] or triamcinolone-lidocaine injections (96.7% vs. 85.2%) [49].

Tuina massage, specifically one-finger pushing, when used in conjunction with warm acupuncture at points ST7, ST6, and GB3, resulted in a 96.7% success rate compared with 86.7% success rate in the diclofenac-chlorzoxazone control group [improvements in muscle movement, joint noise, and tenderness were statistically significant (p < 0.01)] [50].

Commonly utilized acupoints in TMD treatment include ST7, SI19, and LI4, which have been associated with reducing facial inflammation. ST36 is frequently added to treatment protocols for reinforcing overall therapeutic effect. In a study by Hua et al [51], positive outcomes (including mouth opening range, local pain reduction, difficult chewing) were reported when combining these points with ST37 and one-finger Tuina therapy. A visual summary of the benefits of both warm acupuncture and EA is provided in (Figure 2).

Figure 2

Warm acupuncture and electroacupuncture: standalone and combined use with clinical benefits.

2. TCM EA

EA involves the application of low-frequency electrical currents, to inserted acupuncture needles, to potentially enhance therapeutic effects [52]. Some studies indicate that EA may have advantages over manual acupuncture in certain conditions; however, the overall superiority of EA remains inconclusive [53]. EA is frequently used as part of combination therapies for TMD, which has a multifactorial etiology.

In a study by Liu et al [54], EA was administered at GV20 and EX-HN3 alongside psychotherapy, and it was reported that significantly better treatment outcomes (including disappearance of clinical symptoms, restoration of normal joint movement, discomfort reduction) compared with EA alone were observed (87.5% vs. 62.5%). In the study [54], both groups received an identical EA protocol. The treatment group also received adjunctive psychotherapy, and the aim was to evaluate the combined therapeutic effect. As such, the study did not isolate the efficacy of EA alone but rather explored whether adding psychotherapy to EA yielded a superior outcome compared with EA alone. Another clinical trial combined EA at Ashi points, GB3, ST7, LU7, SI19, EX-HN20, and SJ17 with infrared therapy and moxibustion, achieving superior early response rates and overall effectiveness (including mouth opening, pain reduction) compared with controls (97.8% vs. 82.2%, p < 0.05) [55].

In a study by Wang et al [56], EA (applied at ST7, ST6, LI4, Ashi points) was compared with triamcinolone-lidocaine injections, and it was reported that EA resulted in greater improvements in mouth opening, pain relief, and prevention of recurrence over a 6-month follow-up period. In another study [57] where 40Hz EA was applied at ST7, EX-HN20, SI19, and LI4, combined with manual therapy, better outcomes (including pain reduction, mouth opening, chewing pain reduction) were observed when compared with manual therapy alone (97.5% vs. 84.3%).

Research, using an animal model of TMD, supported EA’s anti-inflammatory effects [58]. EA at ST7 (1 mA) significantly reduced interferon and interleukin-6 levels in mice [58]. A clinical study by Que and Xie [59] demonstrated that EA combined with moxibustion at ST7 and EX-HN20 outperformed corticosteroid-lidocaine injections (96.8% vs. 83.9%) in improving pain, and mouth opening range. EA at SJ3, ST7, and SI19 produced a better reduction in the level of pain (VAS scores) due to TMD-associated symptoms and improved function compared with traditional acupuncture (86.7% vs. 70%) [60].

Contrasting findings were reported by Zhu et al, who observed that warm needling for TMD, when combined with prednisone, and vitamin B, was more effective than EA alone (94% vs. 80%), and had significantly lower recurrence rates at 6 months (15.8% vs. 73.7%) [61]. Table 1 provides a summary of the key clinical studies discussed in this review.

Table 1

Summary of Clinical Studies on Acupuncture for TMD

Discussion

TMD is a multifactorial condition characterized by pain, joint sounds, and restricted jaw movement. This review examined clinical trials and observational studies assessing acupuncture, including various techniques, for alleviating TMD symptoms. The evidence suggests that acupuncture may improve symptoms such as pain, limited mouth opening, and joint dysfunction. Some studies also report a reduction in symptom recurrence compared with conventional treatments thus, supporting acupuncture as a potential integrative approach for long-term management.

TMD involves both muscular and joint dysfunction and frequently presents with associated symptoms including headaches, neck, and shoulder pain [62,63]. Its complex etiology and delayed diagnosis contribute to chronicity and treatment challenges. Western treatments commonly include NSAIDs, muscle relaxants, glucosamine, hyaluronic acid injections [64], opioids, psychotropic drugs, platelet-rich plasma [65], and anxiolytics [66]. While these interventions can alleviate symptoms, they may not address underlying pathogenic mechanisms, and can pose challenges for patients with polypharmacy or contraindications. Physiotherapy and manual therapy, such as pterygoid muscle massage and joint mobilization, have shown effectiveness, with a large-scale study reporting symptom improvement in over 90% of patients following interventions like muscle fiber elongation and warm compresses [67]. Adjunctive noninvasive therapies such as magnetotherapy and photobiomodulation have also demonstrated benefits when combined with standard care [68,69].

Within TCM, acupuncture is grounded in the concept that pain arises from Qi stagnation, blood stasis, or external pathogenic factors such as cold or wind [70,71]. When defensive Qi is weakened, pathogenic factors can invade the meridians, obstructing energy flow, and result in discomfort. Treatment aims to expel these factors while reinforcing Qi (vital energy), often emphasizing kidney Qi, depending on the diagnosed pattern [72,73]. The body’s 14 meridians connect internal organs to the surface and regulate Qi movement, forming the basis for acupuncture interventions [74].

Several acupoints have been identified as particularly relevant in TMD treatment. Points such as GB2, SI19, ST6, and SJ17 are frequently utilized to address craniofacial symptoms. For example, GB2 and SI19 are commonly used in conditions related to wind invasion and Qi blockage, such as facial paralysis [75]. GB2 combined with SJ21 has shown efficacy in relieving tinnitus [76] and sensorineural hearing loss [77]. ST6, located near the masseter muscle, is associated with oral and dental health, and a meta-analyses of orofacial pain studies determined that treatment at ST6 provided relief to reduce symptoms and disability for patients [78]. SJ17, part of the triple energizer (sanjiao) meridian near the mandible, is used to treat facial palsy and post-stroke dysphagia, with studies indicating enhanced swallowing function when combined with triple tongue acupuncture [79,80].

Techniques such as EA and warm needling may offer enhanced benefits over standard acupuncture. TCM theory suggests that pain results from stagnation and cold accumulation; thus, warming the meridians via moxibustion or warm needling is thought to promote Qi flow and reduce discomfort [81]. EA provides continuous stimulation, which may augment treatment effects, though robust clinical data are warranted. Some studies have noted that TMD pain follows meridian pathways and that acupuncture points may anatomically correspond to myofascial trigger zones, potentially explaining acupuncture’s effects in musculoskeletal conditions [82].

Clinically, acupuncture, including EA and warm needling, has been reported to reduce joint clicking, alleviate pain, restore jaw mobility, and improve masticatory function. Additionally, several studies suggest acupuncture may reduce symptom recurrence compared with conventional treatments. Its relatively favorable safety profile and minimal drug interaction risk has been noted as advantageous, particularly for older adults, and patients managing complex medication regimens [83].

Although this review supports acupuncture for TMD, it is important to note that most of the included studies, were predominantly conducted in China, and did not specify the temporomandibular disorder subtype according to the Diagnostic Criteria for Temporomandibular Disorders, such as myalgia or arthralgia. Instead, diagnoses were generally based on clinical symptoms such as joint pain, limited mouth opening, and joint noises and researchers followed traditional Chinese dental diagnostic references. This lack of subtype classification limits the capacity to analyze and compare the efficacy of acupuncture techniques for specific TMD categories. Future research adopting standardized subtype criteria would enhance clinical interpretation and guide more targeted treatment approaches.

Conclusion

Warm acupuncture and EA appear to be effective interventions for managing TMD, with clinical studies reporting improvements in jaw function, pain relief, and overall symptom reduction. These therapies may offer a favorable safety profile compared to conventional pharmacological treatments. However, the heterogeneity of study designs in this review, and the lack of clear reporting on TMD subtypes limit definitive conclusions. To strengthen the clinical applicability of these findings, high-quality, randomized, controlled trials with standardized outcome measures, and clearer subtype diagnostic classification are warranted. Furthermore, mechanistic studies exploring the biological effects of acupuncture on TMD pathophysiology could provide important insights into its therapeutic potential.

Supplementary Materials

Data Availability

All relevant data are included in this manuscript.

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