Transcutaneous Mandibular Nerve Electrical Stimulation for the Management of Pain and Function in Patients With Temporomandibular Disorders
Phase: NA
Conditions: Temporomandibular Disorder
Sponsor: OrigenKinesis fisioterapia

 
 
 
 
 
 
 
PERCUTANEOUS ELECTRICAL NERVE STIMULATION OF THE MANDIBULAR 
NERVE FOR THE MANAGEMENT OF PAIN AND FUNCTIONALITY IN 
PATIENTS WITH TEMPOROMANDIBULAR DISORDERS. 
 
 
Controlled and Randomized Trial. 
 
  
  
Study Protocol 
The sample subjects will include patients attending the Origenkinesis physiotherapy center in 
Alcorcón (Madrid). Patients under the age of 18 will not be admitted to the study. Patients will 
also be assessed using the research diagnostic criteria for temporomandibular disorders 
(RDC/TMD) introduced by Dworkin and LeResche in 1992. This allows standardization of 
procedures for epidemiological studies, the unification of diagnostic and exploratory criteria for 
TMD, and comparison of results with other similar studies. All researchers will be trained and 
calibrated according to the adopted standards presented on the official website of the 
International RDC/TMD Consortium. Participants will be randomly allocated to two groups: 1) 
an experimental group receiving an intervention based on PENS (Percutaneous Electrical Nerve 
Stimulation), manual therapy, and exercises; 2) a control group receiving only manual therapy 
and exercises. Randomization will be concealed and carried out using the GraphPad program. 
All patients will be informed about the study participation terms and will give their informed 
written consent during enrollment. The study will take place at the Origenkinesis physiotherapy 
and exercise center located at 7 Las Gardenias Street, Alcorcón (Madrid). The evaluator will be 
a physiotherapist specializing in musculoskeletal and neural pain, experienced in managing 
patients with TMD, who will analyze participants without knowing their assignment to the 
experimental or control group. Based on observations during the evaluation process, the 
physiotherapist will explain to the patient the findings from the examination, the suspected 
condition, and propose the treatment plan. In the first session, each patient will undergo a 
medical history review and a comprehensive examination to rule out any possible 
contraindication suggesting an underlying medical condition. Before the specific evaluation of 
temporomandibular dysfunction and pain, a physical examination of the cervical spine will be 
performed. The cervical spine examination will include an active range of motion test for 
flexion, extension, bilateral lateral flexion, and rotation without/with overpressure. In the 
temporomandibular examination, the range of mouth opening will initially be measured using 

a calibrated Therabite® System device. Then, pain will be assessed using the NPRS scale at rest 
and with maximum possible bite force. Subsequently, a manual trigger point screening will be 
conducted on the masseter muscle, followed by algometric measurement at tender points of 
the masseter. Before and after treatment, we will measure masseter activation using surface 
electromyography during maximum occlusion and chewing gum. Before commencing 
treatment, the patient will complete a disability-related TMD questionnaire, a self-assessed 
quality of life questionnaire, and the Helkimo and Krogh-Paulsen questionnaires. At the fourth 
final assessment, they will fill these out again alongside a GROC (Global Rating of Change) 
satisfaction scale regarding the treatment. 
 
Statistical Analysis Plan 
A controlled and randomized study with single blinding. Sample size estimation will be 
conducted using the GPower 3.1 program with the following parameters: effect size of 0.4, 
alpha error of 0.05, power of 0.80, two groups, and four measurements. Considering these 
parameters and a potential 10% loss rate, a sample size of 50 subjects is estimated. In the 
statistical analysis, variable contrasts will be conducted using the SPSS v27 program through 
repeated measures ANOVA if the variables follow a normal distribution. Otherwise, the 
Friedman test will be used. Normality will be checked using Shapiro-Wilk and Kolmogorov 
tests. 
 
 
                                                                                                                    DATE:  25/7/2023