Temporomandibular dysfunction (TMD) is a set of changes that affects the muscles of mastication, temporomandibular joint, teeth, and associated periodontal and orofacial structures. According to Traditional Chinese Medicine, the imbalance of energy (Qi) circulating in the acupuncture meridians is always the primary etiologic cause of any physical manifestation. The aim of this study was to describe the patterns of Qi imbalance in patients with TMD by means of an objective measurement. The clinical study was conducted at the Piracicaba Dental School (FOP/Unicamp), in Piracicaba-SP, Brazil. We evaluated 40 adult volunteers with TMD. The Qi measurement was carried out by the researcher using the Ryodoraku method using 24 points representing the 12 acupuncture meridians: LU9 (Taiyuan), PC7 (Daling), HT7 (Shemen), SI5 (Yanggu), TE4 (Yangchi), LI5 (Yangxi), SP3 (Taibai), LR3 (Taichong), KI3 (Taixi), BL64 (Jinggu), GB40 (Qiuxu), and ST42 (Chongyang). The average total Qi of 40 volunteers (21.7 μA ± 1.5), was below the normal range (40–60 μA) and was classified as deficiency of Qi (empty). The coupled meridians that showed the highest Qi imbalance were the kidney (29.4 μA ± 2.8) and bladder (13.8 μA ± 1). The Qi planes with greatest imbalance were the Shao Yang and Shao Yin. In conclusion, volunteers with TMD presented a pattern of Qi deficiency, and the most prevalent imbalance patterns identified were in the kidney and bladder coupled meridians and in the energetic planes Shao Yin (heart/kidney) and Shao Yang (triple energizer/gall bladder).
Research Article

Patterns of Energy Imbalance of the Meridians in Patients with Temporomandibular Dysfunction
1Department of Social Dentistry of the Piracicaba Dental School, State University of Campinas, Av. Limeira, 901 – Areão, CEP: 13414-903, Piracicaba, São Paulo, Brazil
2Brazilian Medical College of Acupuncture, Rua Itapeva, 574, CJ. 71 A, Bela Vista, CEP: 01332-000, São Paulo, SP, Brazil
2018; 11(1): 1-6
Published February 1, 2018 https://doi.org/10.1016/j.jams.2017.11.002
Copyright © Medical Association of Pharmacopuncture Institute.
Abstract
Keywords
1. Introduction
The temporomandibular joint (TMJ), as well as other joints of the human body, is vulnerable to both extrinsic and intrinsic influences, as well as age-dependent changes. This vulnerability can be expressed as intermittent or continuous pain in various parts of the head and neck [1]. Temporomandibular dysfunction (TMD) is a set of changes that affect the chewing muscles, the TMJ, teeth, and the periodontal- and orofacial-associated structures. The etiology is multifactorial; inflammatory and infectious disorders, trauma, and hormonal changes have been cited causes of TMD, and it is frequently associated with parafunctional habits and psychosocial disorders [2]. The symptoms commonly associated with TMD include TMJ pain, generalized orofacial pain, chronic headaches and earaches, jaw dysfunction, including hyper and hypomobility, limited movement or locking of the jaw, painful clicks or noises at the opening or closing of the mouth, and difficulty to chew or to talk [3]. Due to the multifactorial etiology and the self-limiting nature of TMDs and because of the effectiveness of noninvasive therapies, their use has been recommended as initial therapies for patients suffering from TMD [4].
Traditional Chinese Medicine (TCM), of which acupuncture forms part, is based on the principle that there is an immaterial and invisible substance, which we call energy (Qi) that circulates through channels or meridians. Qi imbalance is always the primary etiological cause of any physical manifestation. In TCM, the disease has no name; it is a state of imbalance that can manifest itself as Qi deficiency, which means the same as Yin syndrome (deficiency/empty) or as excess Qi that means the Yang syndrome (excess/plenitude) [5]. The acupuncture involves the stimulation of certain points along to the meridians making the free flow of Qi possible [6].
An objective way of measuring this Qi is based on the Ryodoraku method developed by Dr Nakatani in Japan in 1947 [7]. Dr Nakatani noted the existence of electric conductance points on the body and organized them into Ryodorakus; that is, electricity-conducting routes whose path is similar to the meridians route. He related 24 Ryodoraku Points Representative of Measurement (PRRM), twelve on each side of the body (right and left), which can describe the level of Qi in the 12 main meridians of acupuncture, because they are points of high concentration of Qi, the majority of which are source points. The values of the measurements are represented in a bioenergetic graph or Ryodoraku graph [8]. These values may reflect the conditions of the meridians and their relative organs, by the analysis and comparison of the changes occurring in microelectrical current [9].
Acupuncture has been used in patients with TMD as an alternative, complementary therapy, or even the main treatment for the reduction of painful symptoms and improvement of oral function [10]. TCM uses the fundamental principles of Yin and Yang to establish the diagnosis and to seek treatment to solve the problems of human pathology [5, 11]. Therefore, it is extremely important to know the energetic manifestations and the imbalance patterns that occur in the meridians in relation to the pathology determined in the case of the present work, the TMD, because they will lead us to the correct use of the energetic therapeutic resources of acupuncture.
The aim of this study was to describe the patterns of Qi imbalance in patients with TMD, by means of the Ryodoraku method.
2. Material and methods
2.1. Declaration of ethics
The study was approved by the Research Ethics Committee of Piracicaba Dental School-UNICAMP, under the protocol no. 109/2014 and was conducted between July 2015 and June 2016, at the Specialization Clinic of the Piracicaba Dental School (FOP/UNICAMP), in Piracicaba-SP, Brazil and registered on the Platform of Brazilian Clinical Trials under RBR-77y2sp.
2.2. Inclusion and exclusion criteria
Adult volunteers from the Piracicaba Dental School and from the Center of Dental Specialties of the city of Piracicaba, of both sexes, aged 20 to 50 years, with TMD of muscular or mixed origin, with or without mouth opening limitation according to the Research diagnostic criteria for temporomandibular disorders [12], were included. Patients with severe trauma or TMJ infections, under treatment with analgesic and/or antiinflammatory drugs, pregnant women, patients who reported being afraid of a needle or who were undergoing some other treatment for TMD, edentulous patients, and patients with total dental prostheses were excluded.
2.3. Participants
Initially, 77 volunteers with TMD, from the FOP personnel (students, patients, and employees) and those from the Center of Dental Specialties of the city of Piracicaba were recruited; but 34 were excluded from the study: 16 because they did not meet all the inclusion criteria, 10 because they gave up participating, and eight for other reasons. Thus, the initial sample consisted of 43 volunteers.
2.4. TMD assessment
To select patients with TMD of muscular or mixed origin, with or without mouth opening limitation, the questionnaire the research diagnostic criteria for temporomandibular disorders—Axis I and Axis II [12] was applied.
2.5. Energy assessment
The researcher performed Qi measurement in the 43 volunteers, after positioning the patient in the dental chair, in dorsal decubitus position, after resting for five minutes.
The electrical conductance of the PRRM was measured with the “Ryodoraku RDK RE/NKL System” device, manufactured by RDK/NKL Produtos Eletrônicos Ltda., Brusque-SC, Brazil. This device is a portable data acquisition unit that works directly connected to a universal serial bus (USB) port of a personal computer (a Dell notebook: Inspiron 5420—Intel Core i5, Windows 8.1, manufactured by Dell Computadores do Brasil Ltda, in Hortolândia-SP, Brazil). The apparatus is equipped with two electrodes: one of the electrodes is a stationary (grip) electrode made of stainless steel that the volunteer holds with one hand and the other is the measuring electrode manipulated by the researcher. The measuring electrode is equipped with a disposable tip with cotton (swab) moistened with water, which touches the skin at the measuring points in the opposite hand. It is recommended that contact of the operator's hands with the patient's body must be avoided. The pressure of the measuring electrode on the skin can vary from 60 to 150 grams, and in the present study, a pressure of 100 grams was established with use of the traditional direct current technique (200 μA maximum in closed circuit). The probe was applied and held immobile on the point for 1 second at each measurement point (acquisition time), applying direct current of 12 V [8]. The conductance values of each meridian of the right side and left side were expressed in the Ryodoraku graph by microamperes (μA), as exemplified in Fig. 1.
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Figure 1.Example of Ryodoraku graph with alterations in the kidney and bladder meridians. P (lung-LU); PC (pericarium-PC); C (heart-HT); ID (small intestine-SI); TA (triple energizer-TE); IG (large intestine-LI); BP (spleen-SP); F (liver-LR); R (kidney-KI); B (bladder-BL); VB (gallbladder-GB); E (stomach-ST); E/D (left side/right side).
There are 24 PRRMs representing the 12 acupuncture meridians (12 on each side of the body) and they are located on the wrists (right and left): lung (LU9-Taiyuan), pericardium (PC7-Daling), heart (HT7-Shemen), small intestine (SI5-Yanggu), triple energizer (TE4-Yangchi), large intestine (LI5-Yangxi) and on the feet (right and left): spleen (SP3-Taibai), liver (F3-Taichong), spleen (BP3-Taibai), liver (LR3-Taichong), kidney (KI3-Taixi), bladder (BL64-Jinggu), gallbladder (GB40-Qiuxu), stomach (ST42-Chongyang) [8].
In the Ryodoraku graph the Qi between 40–60 μA is considered within the range of normality, capable of being classified into three levels of excess (fullness) upwards of this or, 3 levels of deficiency (empty) down, as represented in Table 1.
-
Table 1 . Classification of imbalances according to the energy level in the Ryodoraku graph (Pérez, 2013).
Energy levels (μA) Classification of imbalance 110–160 Large Qi excess 110–70 Qi excess 70–60 Slight Qi excess 60–40 Normality 40–30 Slight Qi deficiency 30–10 Qi deficiency (empty) 10-5 Qi anergy Qi = energy.
To identify the Qi imbalance patterns, the Ryodoraku graphs obtained of the volunteers with TMD were analyzed by comparing the mean Qi values of the meridians.
2.6. Data analysis
In the analysis of the data, a more descriptive approach was adopted comparing the means of each meridian in isolation and also comparing the mean of the total Qi (of the 12 meridians). For this calculation, the mean between the right and left sides of each meridian was used.
Another analysis was carried out according to the meridian interrelationships in Qi circulation according to the concepts of TCM. Two types of relationships were evaluated: coupled meridians and Qi planes.
Coupled meridians are the interrelationships between the opposite polarities of meridians belonging to the same movement: liver (LR) and gallbladder (GB); heart (HT) and small intestine (SI); pericardium (PC) and triple energizer (TE); spleen (SP) and stomach (ST); lung (LU) and large intestine (LI); kidney (KI); and bladder (BL) [5, 13, 14].
The Qi planes are the interrelationships between meridians of the same polarity: Tai Yang (BL and SI), Shao Yang (TE and GB), Yang Ming (LI and ST), Tai Yin (LU and SP), Jue Yin (PC and LR), and the Shao Yin (HT and KI) [5].
Thus, the differences between the means of the meridians constituting each pair of coupled meridians and the means of the meridians constituting each Qi plane were calculated first; and then the means of the differences in each relationship analyzed were calculated. The largest differences were considered those representing the greatest imbalance for the conditions studied.
For data analysis, the Excel software (Microsoft Office Professional Plus 2013) was used, and the values are presented as mean (±standard error of the mean).
3. Results
The final sample consisted of 43 volunteers, but three volunteers were excluded from the analysis because they did not present the complete data. Thus, the study was concluded with 40 volunteers (32 women and 8 men) with mean age of 36.5 years (±1.4). The volunteers reported that they had presented a TMD problem for an average of 9.2 years (±1.3). In the present study, the results presented refer to those that described the Qi imbalance profile of the volunteers, before any procedure had been performed.
3.1. The total energy means of all the meridians
The mean Qi (of all meridians) of the 40 volunteers (21.7 μA ± 1.5) was below the normal range (40–60 μA) and classified as a deficiency pattern (empty). Considering the 12 regular meridians in the group of 40 volunteers, the KI meridian (29.4 μA ± 2.8) was that with the highest Qi mean, and the BL meridian (13.8 μA ± 1) presented the lowest mean (Fig. 2).
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Figure 2.Mean and standard error of the mean: energy of meridians in adults with TMD. Piracicaba, 2016. LU (lung), PC (pericardium), HT (heart), Si (small intestine), TE (triple energizer), LI (large intestine), SP (spleen), LR (liver), KI (kidney), BL (bladder), GB (gallbladder), ST (stomach). TMD = temporomandibular dysfunction.
3.2. Comparing the coupled meridians
The coupled meridians that presented the highest Qi imbalance (mean of the differences) were the meridians of the KI (29.4 μA ± 2.8) and the BL (13.8 μA ± 1) with an average of difference of (15.6 μA ± 2.4) between them (Fig. 3).
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Figure 3.Mean and standard deviation of energy difference between coupled meridians in adults with TMD. Piracicaba, 2016. LR/GB: liver/gallbladder; HT/SI: heart/small intestine; TE/PC: triple heater/pericardium; SP/ST: spleen/stomach; LU/LI: lung/large intestine; KI/BL: kidney/bladder. TMD = temporomandibular dysfunction.
3.3. Comparing the energy planes
Considering the Qi planes, the largest imbalance (highest mean of the differences) between the meridians occurred in the Shao Yang plane formed by the triple heater meridians (25.8 μA ± 2.4) and the gallbladder (15.1 μA ± 1.7) and in the Shao Yin plane formed by the heart (18.7 μA ± 1.5) and kidney meridians (29.4 μA ± 2.8). The mean value of the difference was 10.7 μA ± 2.3 for the Shao Yang plane and 10.7 μA ± 2.4 for the Shao Yin plane (Fig. 4).
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Figure 4.Mean and standard error of the mean: energy difference in the energy planes in adults with TMD. Piracicaba, 2016. SI/BL: small intestine/bladder; TE/VB: triple energizer/gallbladder; LI/ST: large intestine/stomach; LU/SP: lung/spleen; PC/LR: pericardium/liver; Ki/HT: kidney/heart. TMD = temporomandibular dysfunction.
4. Discussion
In our study, the 40 volunteers with TMD had a mean Qi of 21.7 μA ± 1.5 below that of the normal range (40–60 μA), classified as an Qi deficiency pattern (empty); although, in isolation, some meridians presented excess Qi. The Qi deficiency is a more frequent cause of internal and long-term pathologies and the resulting diseases are, as a rule, chronic diseases [11]. Our study showed that the mean time of suffering from TMD reported by the volunteers was 9.2 years, thus confirming the relationship between TMD chronicity and Qi deficiency. The Qi deficiency of the volunteers may mean that they had consumed their ancestral (inherited) nonrenewable Qi that should be preserved to maintain their health. Thus, identifying this Qi deficiency pattern is important, because patients could be provided with guidelines about improving their diet, sleep, breathing, stress, and emotions control, because these conditions could aggravate or perpetuate the TMD problem. These recommendations might not be provided if TMD were approached from the point of view of Western Medicine only, which does not take into account patients' Qi levels.
TCM is based on three basic pillars: the Yang/Yin theory, the five movements, and the Zang Fu (organs and viscera) [10, 15].
In TCM, the Yang-viscera and the Yin-organ form a functional unit called coupled channels or coupled meridians, establishing an Qi circulation of opposite polarities (Yin/Yang) but belonging to the same phase (five phase theory). That relationship promotes an exterior–interior connection creating a mutual interdependence for the maintenance of vital functions. Thus, in the search for Qi balance, the meridian of LU connects to IG (metal phase); KI to BL (water phase); LR to GB (wood movement); HT to SI (fire phase); PC to TE (fire phase); and SP to ST (earth phase). If there is disharmony between these channels, the body becomes more susceptible to invasion by the internal and external factors of disease.
In our research, the KI (YIN) and BL (YANG) coupled meridians presented the highest imbalance with mean of the difference 15.6 μA between them. According to Pérez (2013) coupled meridians with differences above 40 μA need Qi regulation to obtain balance; however, we point out that the mean of the total Qi (21.7 μA) was classified as an Qi deficiency pattern, below 30 μA (Table 1), therefore, we considered this difference representative of imbalance. The Ki meridian stores the Jing (essence); and among other functions, it is responsible for the production of synovial fluids, nourishes the bones, ears, joints, and teeth, which are considered extensions of the bones in TCM [11]. Some of the symptoms reported by patients with TMD were TMJ pain and otologic manifestations such as tinnitus, earache, and vertigo [4] which helped explain imbalance between the coupled (KI and BL) meridians. If this imbalance was maintained for an extended period of time, it may cause TMD.
The Qi channels of the same polarity (Yang-Yang) and (Yin-Yin) also establish bonds between themselves that are distributed in the body forming Qi layers, from the most superficial to the deepest and are called Qi planes [5]. There are six Qi planes named from the outer to the innermost: Tai Yang (bladder and small intestine), Shao Yang (triple energizer and gallbladder), Yang Ming (large intestine and stomach), Tai Yin (lung and spleen), Jue Yin (pericardium and liver) and Shao Yin (heart and kidney). Thus, these planes establish a superficial/intermediate/deep relationship in the human body [5].
Regarding the Qi planes, the Shao Yang (TE/VB) and the Shao Yin (HT/KI) were the planes that showed the greatest imbalance between their constituent meridians, with mean of the differences of (10.7 μA ± 2.3) and (10.7 μA ± 2.4), respectively. The mean Qi values of these meridians were TE (25.8 μA ± 2.4) and GB (15.1 μA ± 1.7) and Shao Yin plan HT (18.7 μA ± 1.5) and KI (29, 4 μA ± 2.8). Considering the Qi deficiency pattern of the volunteers, the values of the differences presented may be considered indicative of an imbalance. According to Pérez (2010), the Shao Yin plane dominates the endogenous thermogenic functions (cold and heat) and the fundamental psychic functions. Studies have documented that anxiety, depression, emotional tension, and stress also act as etiological factors for TMD [4, 16], corroborating involvement of the Shao Yin plane. The HT meridian may be involved in the affection of emotions because TMD has a very significant emotional component related to anxiety and stress that can trigger clenching/bruxism and muscle and joint pain. When this emotional state persists for a long time it can cause a psychosomatic changes and lead to TMD. According to TCM, when people prone to KI Yin deficiency are subjected to a chronic anxiety–fear state it may result in symptoms of restlessness and insomnia, consequences of subsequent injury to the HT Yin [17]. The insecurity and fear related to people's lifestyles in the present times generate a great deal of anxiety, and therefore, the KI and HT meridians are subject to Yin deficiency, and the relationship between these patterns of energetic change was demonstrated in our study (Fig. 2).
According to Yamamura (2001), TMJ is especially related to the Shao Yang plane, formed by the triple energizer and gallbladder. In addition, the external paths of the TE and GB meridians are closely related to TMJ, because of the proximity of the location of their acupoints.
Thus, we could say that the Shao Yang plane promotes the TMJ relationship with the exterior (Yang) and the Shao Yin plane forms the relationship with the interior (Yin), and in our study, these two planes were considered those most involved with TMD. These results corroborate the knowledge of TCM, since both planes are responsible for the good functioning of the articulations.
The Ryodoraku method made it possible to establish the Qi diagnosis in volunteers with TMD. Identifying patients' Qi imbalance profile by means of objective measurement makes it easier for Western thinkers to understand the knowledge of TCM, favoring the diagnosis and the treatment of TMD with acupuncture. In addition, patients may receive counseling to improve their eating habits, sleep, breathing, and stress and emotion control to balance their Qi reserves and minimize the deleterious effects on TMJ and especially on the general health.
As a limitation of the study the authors emphasize that this study did not compare Qi of the acupuncture meridians in healthy individuals. In the present study, a convenience sample was used; therefore, it is not representative of the adult population with TMD. On the other hand, it translated the results of a homogeneous sample regarding gender, age, time of TMD, and pain and can be considered indicative of the profile of patients with TMD, because the sample size of the present study was compatible with that of other TMD studies found in the literature.
5. Conclusion
The volunteers with TMD presented Qi deficiency (empty Qi). The most prevalent patterns of imbalances identified by the Ryodoraku method were imbalance of Qi in the coupled meridians of the kidney and bladder and in the energetic planes Shao Yin (heart/kidney) and Shao Yang (triple energizer and gallbladder). Thus, based on the results of our study, we suggest that in the treatment of TMD with acupuncture, the points that regulate the meridians of the kidney, bladder, triple energizer, gallbladder, and heart may be included.
Acknowledgments
The authors thank FAEPEX (Fundo de Apoio ao Ensino, à Pesquisa e a Extensão—UNICAMP) and RDK/NKL Produtos Eletrônicos Ltda., Brusque-SC, Brazil, for their support.
Disclosure statement
The authors declare that they have no conflicts of interest and no financial interests related to the material of this manuscript.
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Related articles in JAMS

Article
Research Article
2018; 11(1): 1-6
Published online February 1, 2018 https://doi.org/10.1016/j.jams.2017.11.002
Copyright © Medical Association of Pharmacopuncture Institute.
Patterns of Energy Imbalance of the Meridians in Patients with Temporomandibular Dysfunction
Vera L. Rasera Zotelli1†*, Cássia M. Grillo1†, Maria L. Bressiani Gil1†, Ronaldo S. Wada1†, Jorge E. Sato2‡, Maria da Luz R. de Sousa1†
1Department of Social Dentistry of the Piracicaba Dental School, State University of Campinas, Av. Limeira, 901 – Areão, CEP: 13414-903, Piracicaba, São Paulo, Brazil
2Brazilian Medical College of Acupuncture, Rua Itapeva, 574, CJ. 71 A, Bela Vista, CEP: 01332-000, São Paulo, SP, Brazil
Correspondence to:Vera L. Rasera Zotelli
Abstract
Temporomandibular dysfunction (TMD) is a set of changes that affects the muscles of mastication, temporomandibular joint, teeth, and associated periodontal and orofacial structures. According to Traditional Chinese Medicine, the imbalance of energy (Qi) circulating in the acupuncture meridians is always the primary etiologic cause of any physical manifestation. The aim of this study was to describe the patterns of Qi imbalance in patients with TMD by means of an objective measurement. The clinical study was conducted at the Piracicaba Dental School (FOP/Unicamp), in Piracicaba-SP, Brazil. We evaluated 40 adult volunteers with TMD. The Qi measurement was carried out by the researcher using the Ryodoraku method using 24 points representing the 12 acupuncture meridians: LU9 (Taiyuan), PC7 (Daling), HT7 (Shemen), SI5 (Yanggu), TE4 (Yangchi), LI5 (Yangxi), SP3 (Taibai), LR3 (Taichong), KI3 (Taixi), BL64 (Jinggu), GB40 (Qiuxu), and ST42 (Chongyang). The average total Qi of 40 volunteers (21.7 μA ± 1.5), was below the normal range (40–60 μA) and was classified as deficiency of Qi (empty). The coupled meridians that showed the highest Qi imbalance were the kidney (29.4 μA ± 2.8) and bladder (13.8 μA ± 1). The Qi planes with greatest imbalance were the Shao Yang and Shao Yin. In conclusion, volunteers with TMD presented a pattern of Qi deficiency, and the most prevalent imbalance patterns identified were in the kidney and bladder coupled meridians and in the energetic planes Shao Yin (heart/kidney) and Shao Yang (triple energizer/gall bladder).
Keywords: acupuncture points, dentistry, meridians, temporomandibular joint, temporomandibular joint disorders
1. Introduction
The temporomandibular joint (TMJ), as well as other joints of the human body, is vulnerable to both extrinsic and intrinsic influences, as well as age-dependent changes. This vulnerability can be expressed as intermittent or continuous pain in various parts of the head and neck [1]. Temporomandibular dysfunction (TMD) is a set of changes that affect the chewing muscles, the TMJ, teeth, and the periodontal- and orofacial-associated structures. The etiology is multifactorial; inflammatory and infectious disorders, trauma, and hormonal changes have been cited causes of TMD, and it is frequently associated with parafunctional habits and psychosocial disorders [2]. The symptoms commonly associated with TMD include TMJ pain, generalized orofacial pain, chronic headaches and earaches, jaw dysfunction, including hyper and hypomobility, limited movement or locking of the jaw, painful clicks or noises at the opening or closing of the mouth, and difficulty to chew or to talk [3]. Due to the multifactorial etiology and the self-limiting nature of TMDs and because of the effectiveness of noninvasive therapies, their use has been recommended as initial therapies for patients suffering from TMD [4].
Traditional Chinese Medicine (TCM), of which acupuncture forms part, is based on the principle that there is an immaterial and invisible substance, which we call energy (Qi) that circulates through channels or meridians. Qi imbalance is always the primary etiological cause of any physical manifestation. In TCM, the disease has no name; it is a state of imbalance that can manifest itself as Qi deficiency, which means the same as Yin syndrome (deficiency/empty) or as excess Qi that means the Yang syndrome (excess/plenitude) [5]. The acupuncture involves the stimulation of certain points along to the meridians making the free flow of Qi possible [6].
An objective way of measuring this Qi is based on the Ryodoraku method developed by Dr Nakatani in Japan in 1947 [7]. Dr Nakatani noted the existence of electric conductance points on the body and organized them into Ryodorakus; that is, electricity-conducting routes whose path is similar to the meridians route. He related 24 Ryodoraku Points Representative of Measurement (PRRM), twelve on each side of the body (right and left), which can describe the level of Qi in the 12 main meridians of acupuncture, because they are points of high concentration of Qi, the majority of which are source points. The values of the measurements are represented in a bioenergetic graph or Ryodoraku graph [8]. These values may reflect the conditions of the meridians and their relative organs, by the analysis and comparison of the changes occurring in microelectrical current [9].
Acupuncture has been used in patients with TMD as an alternative, complementary therapy, or even the main treatment for the reduction of painful symptoms and improvement of oral function [10]. TCM uses the fundamental principles of Yin and Yang to establish the diagnosis and to seek treatment to solve the problems of human pathology [5, 11]. Therefore, it is extremely important to know the energetic manifestations and the imbalance patterns that occur in the meridians in relation to the pathology determined in the case of the present work, the TMD, because they will lead us to the correct use of the energetic therapeutic resources of acupuncture.
The aim of this study was to describe the patterns of Qi imbalance in patients with TMD, by means of the Ryodoraku method.
2. Material and methods
2.1. Declaration of ethics
The study was approved by the Research Ethics Committee of Piracicaba Dental School-UNICAMP, under the protocol no. 109/2014 and was conducted between July 2015 and June 2016, at the Specialization Clinic of the Piracicaba Dental School (FOP/UNICAMP), in Piracicaba-SP, Brazil and registered on the Platform of Brazilian Clinical Trials under RBR-77y2sp.
2.2. Inclusion and exclusion criteria
Adult volunteers from the Piracicaba Dental School and from the Center of Dental Specialties of the city of Piracicaba, of both sexes, aged 20 to 50 years, with TMD of muscular or mixed origin, with or without mouth opening limitation according to the Research diagnostic criteria for temporomandibular disorders [12], were included. Patients with severe trauma or TMJ infections, under treatment with analgesic and/or antiinflammatory drugs, pregnant women, patients who reported being afraid of a needle or who were undergoing some other treatment for TMD, edentulous patients, and patients with total dental prostheses were excluded.
2.3. Participants
Initially, 77 volunteers with TMD, from the FOP personnel (students, patients, and employees) and those from the Center of Dental Specialties of the city of Piracicaba were recruited; but 34 were excluded from the study: 16 because they did not meet all the inclusion criteria, 10 because they gave up participating, and eight for other reasons. Thus, the initial sample consisted of 43 volunteers.
2.4. TMD assessment
To select patients with TMD of muscular or mixed origin, with or without mouth opening limitation, the questionnaire the research diagnostic criteria for temporomandibular disorders—Axis I and Axis II [12] was applied.
2.5. Energy assessment
The researcher performed Qi measurement in the 43 volunteers, after positioning the patient in the dental chair, in dorsal decubitus position, after resting for five minutes.
The electrical conductance of the PRRM was measured with the “Ryodoraku RDK RE/NKL System” device, manufactured by RDK/NKL Produtos Eletrônicos Ltda., Brusque-SC, Brazil. This device is a portable data acquisition unit that works directly connected to a universal serial bus (USB) port of a personal computer (a Dell notebook: Inspiron 5420—Intel Core i5, Windows 8.1, manufactured by Dell Computadores do Brasil Ltda, in Hortolândia-SP, Brazil). The apparatus is equipped with two electrodes: one of the electrodes is a stationary (grip) electrode made of stainless steel that the volunteer holds with one hand and the other is the measuring electrode manipulated by the researcher. The measuring electrode is equipped with a disposable tip with cotton (swab) moistened with water, which touches the skin at the measuring points in the opposite hand. It is recommended that contact of the operator's hands with the patient's body must be avoided. The pressure of the measuring electrode on the skin can vary from 60 to 150 grams, and in the present study, a pressure of 100 grams was established with use of the traditional direct current technique (200 μA maximum in closed circuit). The probe was applied and held immobile on the point for 1 second at each measurement point (acquisition time), applying direct current of 12 V [8]. The conductance values of each meridian of the right side and left side were expressed in the Ryodoraku graph by microamperes (μA), as exemplified in Fig. 1.
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Figure 1. Example of Ryodoraku graph with alterations in the kidney and bladder meridians. P (lung-LU); PC (pericarium-PC); C (heart-HT); ID (small intestine-SI); TA (triple energizer-TE); IG (large intestine-LI); BP (spleen-SP); F (liver-LR); R (kidney-KI); B (bladder-BL); VB (gallbladder-GB); E (stomach-ST); E/D (left side/right side).
There are 24 PRRMs representing the 12 acupuncture meridians (12 on each side of the body) and they are located on the wrists (right and left): lung (LU9-Taiyuan), pericardium (PC7-Daling), heart (HT7-Shemen), small intestine (SI5-Yanggu), triple energizer (TE4-Yangchi), large intestine (LI5-Yangxi) and on the feet (right and left): spleen (SP3-Taibai), liver (F3-Taichong), spleen (BP3-Taibai), liver (LR3-Taichong), kidney (KI3-Taixi), bladder (BL64-Jinggu), gallbladder (GB40-Qiuxu), stomach (ST42-Chongyang) [8].
In the Ryodoraku graph the Qi between 40–60 μA is considered within the range of normality, capable of being classified into three levels of excess (fullness) upwards of this or, 3 levels of deficiency (empty) down, as represented in Table 1.
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&md=tbl&idx=1' data-target="#file-modal"">Table 1
Classification of imbalances according to the energy level in the Ryodoraku graph (Pérez, 2013)..
Energy levels (μA) Classification of imbalance 110–160 Large Qi excess 110–70 Qi excess 70–60 Slight Qi excess 60–40 Normality 40–30 Slight Qi deficiency 30–10 Qi deficiency (empty) 10-5 Qi anergy Qi = energy..
To identify the Qi imbalance patterns, the Ryodoraku graphs obtained of the volunteers with TMD were analyzed by comparing the mean Qi values of the meridians.
2.6. Data analysis
In the analysis of the data, a more descriptive approach was adopted comparing the means of each meridian in isolation and also comparing the mean of the total Qi (of the 12 meridians). For this calculation, the mean between the right and left sides of each meridian was used.
Another analysis was carried out according to the meridian interrelationships in Qi circulation according to the concepts of TCM. Two types of relationships were evaluated: coupled meridians and Qi planes.
Coupled meridians are the interrelationships between the opposite polarities of meridians belonging to the same movement: liver (LR) and gallbladder (GB); heart (HT) and small intestine (SI); pericardium (PC) and triple energizer (TE); spleen (SP) and stomach (ST); lung (LU) and large intestine (LI); kidney (KI); and bladder (BL) [5, 13, 14].
The Qi planes are the interrelationships between meridians of the same polarity: Tai Yang (BL and SI), Shao Yang (TE and GB), Yang Ming (LI and ST), Tai Yin (LU and SP), Jue Yin (PC and LR), and the Shao Yin (HT and KI) [5].
Thus, the differences between the means of the meridians constituting each pair of coupled meridians and the means of the meridians constituting each Qi plane were calculated first; and then the means of the differences in each relationship analyzed were calculated. The largest differences were considered those representing the greatest imbalance for the conditions studied.
For data analysis, the Excel software (Microsoft Office Professional Plus 2013) was used, and the values are presented as mean (±standard error of the mean).
3. Results
The final sample consisted of 43 volunteers, but three volunteers were excluded from the analysis because they did not present the complete data. Thus, the study was concluded with 40 volunteers (32 women and 8 men) with mean age of 36.5 years (±1.4). The volunteers reported that they had presented a TMD problem for an average of 9.2 years (±1.3). In the present study, the results presented refer to those that described the Qi imbalance profile of the volunteers, before any procedure had been performed.
3.1. The total energy means of all the meridians
The mean Qi (of all meridians) of the 40 volunteers (21.7 μA ± 1.5) was below the normal range (40–60 μA) and classified as a deficiency pattern (empty). Considering the 12 regular meridians in the group of 40 volunteers, the KI meridian (29.4 μA ± 2.8) was that with the highest Qi mean, and the BL meridian (13.8 μA ± 1) presented the lowest mean (Fig. 2).
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Figure 2. Mean and standard error of the mean: energy of meridians in adults with TMD. Piracicaba, 2016. LU (lung), PC (pericardium), HT (heart), Si (small intestine), TE (triple energizer), LI (large intestine), SP (spleen), LR (liver), KI (kidney), BL (bladder), GB (gallbladder), ST (stomach). TMD = temporomandibular dysfunction.
3.2. Comparing the coupled meridians
The coupled meridians that presented the highest Qi imbalance (mean of the differences) were the meridians of the KI (29.4 μA ± 2.8) and the BL (13.8 μA ± 1) with an average of difference of (15.6 μA ± 2.4) between them (Fig. 3).
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Figure 3. Mean and standard deviation of energy difference between coupled meridians in adults with TMD. Piracicaba, 2016. LR/GB: liver/gallbladder; HT/SI: heart/small intestine; TE/PC: triple heater/pericardium; SP/ST: spleen/stomach; LU/LI: lung/large intestine; KI/BL: kidney/bladder. TMD = temporomandibular dysfunction.
3.3. Comparing the energy planes
Considering the Qi planes, the largest imbalance (highest mean of the differences) between the meridians occurred in the Shao Yang plane formed by the triple heater meridians (25.8 μA ± 2.4) and the gallbladder (15.1 μA ± 1.7) and in the Shao Yin plane formed by the heart (18.7 μA ± 1.5) and kidney meridians (29.4 μA ± 2.8). The mean value of the difference was 10.7 μA ± 2.3 for the Shao Yang plane and 10.7 μA ± 2.4 for the Shao Yin plane (Fig. 4).
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Figure 4. Mean and standard error of the mean: energy difference in the energy planes in adults with TMD. Piracicaba, 2016. SI/BL: small intestine/bladder; TE/VB: triple energizer/gallbladder; LI/ST: large intestine/stomach; LU/SP: lung/spleen; PC/LR: pericardium/liver; Ki/HT: kidney/heart. TMD = temporomandibular dysfunction.
4. Discussion
In our study, the 40 volunteers with TMD had a mean Qi of 21.7 μA ± 1.5 below that of the normal range (40–60 μA), classified as an Qi deficiency pattern (empty); although, in isolation, some meridians presented excess Qi. The Qi deficiency is a more frequent cause of internal and long-term pathologies and the resulting diseases are, as a rule, chronic diseases [11]. Our study showed that the mean time of suffering from TMD reported by the volunteers was 9.2 years, thus confirming the relationship between TMD chronicity and Qi deficiency. The Qi deficiency of the volunteers may mean that they had consumed their ancestral (inherited) nonrenewable Qi that should be preserved to maintain their health. Thus, identifying this Qi deficiency pattern is important, because patients could be provided with guidelines about improving their diet, sleep, breathing, stress, and emotions control, because these conditions could aggravate or perpetuate the TMD problem. These recommendations might not be provided if TMD were approached from the point of view of Western Medicine only, which does not take into account patients' Qi levels.
TCM is based on three basic pillars: the Yang/Yin theory, the five movements, and the Zang Fu (organs and viscera) [10, 15].
In TCM, the Yang-viscera and the Yin-organ form a functional unit called coupled channels or coupled meridians, establishing an Qi circulation of opposite polarities (Yin/Yang) but belonging to the same phase (five phase theory). That relationship promotes an exterior–interior connection creating a mutual interdependence for the maintenance of vital functions. Thus, in the search for Qi balance, the meridian of LU connects to IG (metal phase); KI to BL (water phase); LR to GB (wood movement); HT to SI (fire phase); PC to TE (fire phase); and SP to ST (earth phase). If there is disharmony between these channels, the body becomes more susceptible to invasion by the internal and external factors of disease.
In our research, the KI (YIN) and BL (YANG) coupled meridians presented the highest imbalance with mean of the difference 15.6 μA between them. According to Pérez (2013) coupled meridians with differences above 40 μA need Qi regulation to obtain balance; however, we point out that the mean of the total Qi (21.7 μA) was classified as an Qi deficiency pattern, below 30 μA (Table 1), therefore, we considered this difference representative of imbalance. The Ki meridian stores the Jing (essence); and among other functions, it is responsible for the production of synovial fluids, nourishes the bones, ears, joints, and teeth, which are considered extensions of the bones in TCM [11]. Some of the symptoms reported by patients with TMD were TMJ pain and otologic manifestations such as tinnitus, earache, and vertigo [4] which helped explain imbalance between the coupled (KI and BL) meridians. If this imbalance was maintained for an extended period of time, it may cause TMD.
The Qi channels of the same polarity (Yang-Yang) and (Yin-Yin) also establish bonds between themselves that are distributed in the body forming Qi layers, from the most superficial to the deepest and are called Qi planes [5]. There are six Qi planes named from the outer to the innermost: Tai Yang (bladder and small intestine), Shao Yang (triple energizer and gallbladder), Yang Ming (large intestine and stomach), Tai Yin (lung and spleen), Jue Yin (pericardium and liver) and Shao Yin (heart and kidney). Thus, these planes establish a superficial/intermediate/deep relationship in the human body [5].
Regarding the Qi planes, the Shao Yang (TE/VB) and the Shao Yin (HT/KI) were the planes that showed the greatest imbalance between their constituent meridians, with mean of the differences of (10.7 μA ± 2.3) and (10.7 μA ± 2.4), respectively. The mean Qi values of these meridians were TE (25.8 μA ± 2.4) and GB (15.1 μA ± 1.7) and Shao Yin plan HT (18.7 μA ± 1.5) and KI (29, 4 μA ± 2.8). Considering the Qi deficiency pattern of the volunteers, the values of the differences presented may be considered indicative of an imbalance. According to Pérez (2010), the Shao Yin plane dominates the endogenous thermogenic functions (cold and heat) and the fundamental psychic functions. Studies have documented that anxiety, depression, emotional tension, and stress also act as etiological factors for TMD [4, 16], corroborating involvement of the Shao Yin plane. The HT meridian may be involved in the affection of emotions because TMD has a very significant emotional component related to anxiety and stress that can trigger clenching/bruxism and muscle and joint pain. When this emotional state persists for a long time it can cause a psychosomatic changes and lead to TMD. According to TCM, when people prone to KI Yin deficiency are subjected to a chronic anxiety–fear state it may result in symptoms of restlessness and insomnia, consequences of subsequent injury to the HT Yin [17]. The insecurity and fear related to people's lifestyles in the present times generate a great deal of anxiety, and therefore, the KI and HT meridians are subject to Yin deficiency, and the relationship between these patterns of energetic change was demonstrated in our study (Fig. 2).
According to Yamamura (2001), TMJ is especially related to the Shao Yang plane, formed by the triple energizer and gallbladder. In addition, the external paths of the TE and GB meridians are closely related to TMJ, because of the proximity of the location of their acupoints.
Thus, we could say that the Shao Yang plane promotes the TMJ relationship with the exterior (Yang) and the Shao Yin plane forms the relationship with the interior (Yin), and in our study, these two planes were considered those most involved with TMD. These results corroborate the knowledge of TCM, since both planes are responsible for the good functioning of the articulations.
The Ryodoraku method made it possible to establish the Qi diagnosis in volunteers with TMD. Identifying patients' Qi imbalance profile by means of objective measurement makes it easier for Western thinkers to understand the knowledge of TCM, favoring the diagnosis and the treatment of TMD with acupuncture. In addition, patients may receive counseling to improve their eating habits, sleep, breathing, and stress and emotion control to balance their Qi reserves and minimize the deleterious effects on TMJ and especially on the general health.
As a limitation of the study the authors emphasize that this study did not compare Qi of the acupuncture meridians in healthy individuals. In the present study, a convenience sample was used; therefore, it is not representative of the adult population with TMD. On the other hand, it translated the results of a homogeneous sample regarding gender, age, time of TMD, and pain and can be considered indicative of the profile of patients with TMD, because the sample size of the present study was compatible with that of other TMD studies found in the literature.
5. Conclusion
The volunteers with TMD presented Qi deficiency (empty Qi). The most prevalent patterns of imbalances identified by the Ryodoraku method were imbalance of Qi in the coupled meridians of the kidney and bladder and in the energetic planes Shao Yin (heart/kidney) and Shao Yang (triple energizer and gallbladder). Thus, based on the results of our study, we suggest that in the treatment of TMD with acupuncture, the points that regulate the meridians of the kidney, bladder, triple energizer, gallbladder, and heart may be included.
Acknowledgments
The authors thank FAEPEX (Fundo de Apoio ao Ensino, à Pesquisa e a Extensão—UNICAMP) and RDK/NKL Produtos Eletrônicos Ltda., Brusque-SC, Brazil, for their support.
Disclosure statement
The authors declare that they have no conflicts of interest and no financial interests related to the material of this manuscript.
Fig 1.

Fig 2.

Fig 3.

Fig 4.

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Table 1 . Classification of imbalances according to the energy level in the Ryodoraku graph (Pérez, 2013)..
Energy levels (μA) Classification of imbalance 110–160 Large Qi excess 110–70 Qi excess 70–60 Slight Qi excess 60–40 Normality 40–30 Slight Qi deficiency 30–10 Qi deficiency (empty) 10-5 Qi anergy Qi = energy..
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