The objective is to compare the neuromuscular electrical activity and muscle fatigue of the masseter muscles in three groups of patients with different treatments for TMD (GA = Transcutaneous electrostimulation and splint, GB = percutaneous electrostimulation and splint, and GC = Occlusal splint) by means of 6 electromyographic recordings scheduled weekly.

The study population will be patients with TMD who will enter the Physiology Laboratory of the Division of Postgraduate Studies and Research (DEPeI) UNAM, admitted during the period from March to December 2021 The selection of the sample will be carried out by convenience sampling which will be carried out based on the clinical evaluation (considering the inclusion and exclusion criteria). The recruitment period will take place during the period from March to December 2021.

The selected sample will be divided into three groups (GA = transcutaneous electrostimulation and splint, GB = percutaneous electrostimulation and splint, GC = splint); the allocation by group will be made by means of a randomization in balanced blocks. The total sample size calculated for this study was 84 patients, 28 for each group.

The diagnostic process of Temporomandibular Dysfunction (TMD) will be carried out by the Principal Investigator using the Diagnostic Criteria and Investigation of Temporomandibular Disorders (CDI / TMD).

Temporomandibular dysfunction or disorder (TMD) is a functional disorder of the temporomandibular joint (TMJ), and is the cause of non-dental pain in the orofacial region.

TMD presents diagnostic difficulties, the literature suggests objective assessment of neuromuscular activity. Electromyography (EMG) is a reliable tool to determine the degree of functional muscle alteration, the EMG signal can be estimated and characterized by multifractal analysis, for example, the Hurts Index. This method is used successfully in the study of physiological signals with high biological variability (signals: cardiac, cardiovascular, ophthalmological, neuronal, metabolic, etc.), it is considered suitable for the comprehensive analysis of neuromuscular behavior.

The objective is to compare the neuromuscular electrical activity (RMS) and muscle fatigue (Hurst index) of the masseter muscles in three groups of patients with different treatments for TMD (GA = Transcutaneous electrostimulation and splint, GB = percutaneous electrostimulation and splint, and GC = Occlusal splint) by means of 6 electromyographic recordings scheduled weekly.

The clinical examination will be performed in the order of the hands of the clock, beginning with the upper right quadrant. The first review will correspond to the presence of mixed dentition, use of prostheses, number of teeth, muscle pain (with a pressure algometer applying 1.5 kg / cm2 in masseter muscles, and 2.4 kg / cm2 in temporal muscles), joint pain (with algometer pressure applying 1.5 kg / cm2), presence of noises, limitation to mouth opening (with Terabite) and heart rate.

To assess pain by means of muscle and joint palpation with an algometer, the patient will be seated in a relaxed position, the evaluator will place the fine circular surface of the algometer perpendicular to the skin and an increasing pressure of 0.5 kg / cm2 will be applied increasing gradually over one minute until reaching 1.5 kg / cm2.

The patient will be instructed to verbalize the moment when pressure was exerted if a painful sensation was caused by muscle and in the joint area.

Treatment for TMD will be carried out using conventional treatment with an occlusal splint and as an auxiliary method, transcutaneous and percutaneous electrostimulation therapies will be applied by the same operator. The clinical control appointments for signs and symptoms of TMD, splint fitting, electromyographic records and application of electrostimulation therapy as an adjunct to the use of splint, will be scheduled once a week in the Physiology Laboratory during the hours of 9:00 a.m. 1:00 pm and 2:00 pm to 6:00 pm for six consecutive weeks.

The electromyographic recording technique was standardized (Cohen's Kappa 0.7). The recording system (hardware and software) that will be used for the electromyographic evaluation is the Electromyograph 1.2 UNAM-CINVESTAV, which consists of a two-channel system for the analysis of the electromyographic signal that offers greater precision and facilitates muscle assessment through the estimation made by the software of the RMS for its acronym in English (Root Mean Square) and Hurts Index.

The RMS and Hurts Index will be recorded using three electrodes: one placed at the muscular origin, another at the insertion, and finally one in the behind-the-ear area as a ground or neutral electrode. The RMS recording is performed at maximum intercuspation for 30 seconds; the action potential that is expressed in electrical energy will be recorded in microvolts per second (μV / s).

6 electromyographic recordings will be performed on each patient (one record each week) during the time of splint use. Electromyographic recordings will be scheduled as well as follow-up control appointments, to make adjustments to the physiological occlusal splint.

The transcutaneous electrostimulation therapy will be carried out by the Principal Investigator, who will be trained in the ISSSTE Clínica de Especialidades Oriente Leonardo Bravo Complex in the acupuncture service under the guidance of Dr. Roberto Sánchez Ahedo. (Surgeon, Specialist in Family Medicine. Training in acupuncture in different institutions. Master in Medical Education, Doctorate in Education, Professor of various courses in acupuncture from a medical perspective. Academic of the Faculty of Medicine of UNAM.) It will be completed the training process for the application of electrostimulation therapies based on the WHO Guidelines established in the Official Mexican NOM-172-SSA1-1998, which specifies the operating criteria for the practice of human acupuncture and related methods (electrostimulation therapies). The Standard governs that the training of a Physician or Health Personnel to fully exercise these therapies requires training of at least 350 academic hours. For this reason, the principal investigator will complete during this stage the theoretical, practical and clinical preparation course taught by the UNAM Faculty of Medicine "Diploma in Complementary Medicine and Acupuncture" with a total of 450 academic hours lasting one year (August 2019-February 2021), to comply with the training guidelines and basic training for the application of electrostimulation therapies.

For transcutaneous electrostimulation therapy, Kendall® MediTrace 100 conductive adhesive ECG electrodes (pediatric) with a diameter of 2.4 cm, and portable electro-stimulator equipment KWD-808 (professional equipment for electroacupuncture and rehabilitation) will be used.

The patient will be positioned in the dental chair, the superficial area of the skin of the masseter muscle will be cleaned with alcohol and cotton. Two Kendall® MediTrace 100 electrodes will be placed in each masseter muscle (right and left), considering the same references that were used for the electrodes placed for the electromyographic recording; the first electrode is placed at the origin of the masseter muscle or superficial area of the mandibular condyle and the second at the insertion of the masseter muscle at the angle of the mandible. After placing the electrodes, the KWD-808 electroacupuncture device will be connected to the patient by means of two double alligator cables; the alligators will be pressed to the metal head of each electrode: the positive pole (red color) will be connected at the origin of the masseter muscle and the negative pole (black color) at the insertion of the masseter muscle.

Before nerve stimulation, all patients will be informed of the perceived sensation, which in some patients will range from imperceptible to barely noticeable or not very noticeable.

The parameters to be used will be: pulse duration until sensory activation and high intensities, but with an established limit to prevent muscle contraction and that allows maximum comfort for 20 minutes. Current will be transmitted with square or rectangular waveform, the stimulation frequency: two frequency bands (low: 210Hz and high 10140Hz.); wave amplitude: 3050 volts, pulse duration: 40100 msec; and the output intensity: 0.70 (for 100Hz). The treatment time will be 20 minutes; the equipment has the quality of timing itself and after time it will stop transmitting a signal to the patient. The treatment will consist of the application of six consecutive therapies programs weekly.

The transcutaneous electrostimulation therapy will be carried out by the Principal Investigator, who will be trained in the ISSSTE Clínica de Especialidades Oriente Leonardo Bravo Complex in the acupuncture service under the guidance of Dr. Roberto Sánchez Ahedo.

Sterile steel acupuncture needles of 0.25x13mm, disposable AcuBEST brand (FDA 510K), and portable electrostimulator equipment KWD-808 (professional equipment for electroacupuncture and rehabilitation) will be used for percutaneous electrostimulation therapies.

Prior to the placement of therapy, the superficial area of the skin of the masseter muscle will be cleaned with alcohol and cotton. The puncture technique will be carried out by taking the needle through the body (not by the handle), the lower part is held between the thumb and index finger of the right hand, allowing the tip of the needle to pass. Directing the needle to the acupuncture point to insert it quickly (penetrating 5 mm).

Two needles will be placed in the right masseter muscle and two in the left masseter muscle, each one at the reference trigger points (local TMD points), following the "Practical recommendations for the treatment of Temporomandibular Disorders"; the area to be punctured is the origin of the masseter muscle or superficial area of the mandibular condyle anterior to the atrial tragus approximately 1cm away (proximal acupuncture points: Gb3, Si 19, Gb 2, St 7), insertion of the masseter muscle at the angle of the mandible (Proximal acupuncture points: St6, St5). For this study, distal stitches will not be placed.

After placing the needles, the KWD-808 electroacupuncture device will be connected to the patient; The two double alligator cables will be connected to each patient by means of the alligators that will directly press the head of the needles. The positive pole (red color) will be connected at the origin of the masseter muscle and the negative pole (black color) will be placed at the insertion of the masseter muscle.

Before nerve stimulation, all patients will be informed of the perceived sensation, which in some patients will range from imperceptible to barely noticeable or not very noticeable.

The treatment will be carried out every week with a total of six continuous therapies or if the patient deserves it until the remission of symptoms.

The recruitment phase of the sample will be carried out by evaluating the patients, the TMD diagnostic process and the evaluation of inclusion criteria that attend the Physiology Laboratory of DEPeI UNAM during the period from August to December 2020. The randomization will be carried out of patients recruited during this period.

The clinical methodology for the application of the therapies Transcutaneous electrical nerve stimulation and Percutaneous Neuromodulation Therapy will be carried out based on:

• OFFICIAL MEXICAN STANDARD NOM-017-SSA3-2012. Regulation of health services for the practice of human acupuncture and related methods.
• Official Mexican STANDARD NOM-197-SSA1-2000. That establishes the minimum infrastructure and equipment requirements for hospitals and specialized medical care offices.

Inclusion Criteria:

• Patients assigned to the DEPeI Physiology Laboratory.
• Age range 18 to 60 years
• Without prior treatment of TTM or DTM
• Permanent dentition
• With malocclusion
• With prosthetic or implant treatments
• Partially toothless arches
• Bruxists
• Deviation to mandibular opening or closure
• Presence of joint noises depending
• Myofascial or joint pain

Exclusion Criteria:

• Degenerative joint disease
• Periodontal problems
• Orthodontic treatment
• Apparent neurological or sensory disabilities
• Patients with bleeding disorders or with anticoagulant intake
• Patients with pacemakers, defibrillators, or heart conditions
• Epilepsy, thrombophlebitis, active or uncontrolled phlebitis
• Facial wounds or severe acne
• Apparent Neurological or muscular disorders
• Allergic to metal
• Acute inflammatory processes or infections
• Pregnant
• Joint surgical history
• Malignancies
• Degenerative bone diseases
• Fibromyalgia

All collected IPD, all IPD that underlie results in a publication

Blind observer:

A third party (statesman) is used, who does not know the treatment that each person is receiving.

patient, to assess the response.