Effects of Radial Shock Wave Therapy in the Treatment of Temporomandibular Joint Syndrome.

Temporomandibular Disorders (TMDs) are a subgroup of painful orofacial disorders of the stomatognathic system, characterized by TemporoMandibular Joint (TMJ) pain, fatigue of the cranio-cervico-facial muscles (especially the masticatory muscles), limitation of mandibular movement and the presence of a click or crackling sound in the ATM.

The main signs and symptoms associated with TMDs are bruxism (33%), myofascial pain (14%), headache (96%) and functional limitation (93%), the latter being related to posture.

The quality of life of patients with TMD involvement is diminished in various facets of their lives, leading to a private expense for the patient as well as a public expense resulting from a poor referral due to the lack of adequate treatment for TMDs. This expense ranges in Spanish public hospitals at € 146.9 with a minimum of € 52 and a maximum of € 425.

From this study, we are going to carry out a non-invasive, analgesic, anti-inflammatory treatment and without negative side effects for the patient through radial extracorporeal shock waves (rESWT), and manual therapy (TM).

Among the effects produced by shock waves we find that they improve circulation due to increased blood flow and oxygenation, at tissue level the permeability of the membrane increases and its metabolic process, therefore facilitating the activation of tissue regeneration processes experiencing dystrophic changes. Furthermore, shock waves cause anti-inflammatory effects and muscle relaxation.

The main objective of the study is to evaluate the capacity of the shock waves to improve the alterations due to temporomandibular disorders. To meet the above objective, a single-blind randomized clinical trial study has been designed. The selected subjects will be of legal age diagnosed with temporomandibular disorder and those subjects that due to their own characteristics are not able to carry out the study will be excluded. Subjects will receive a weekly physical therapy session for four weeks. Subjects will be randomly assigned to two groups: T1 intervention group consisting of subjects who will receive manual therapy treatment and shock waves and T2 placebo group in which the subjects will receive manual therapy and placebo shock waves.

Subjects will be evaluated using sociodemographic variables such as age, sex, weight, height, Body Mass Index, educational level, work, smoking, alcohol and physical activity and function tests and quality of life questionnaires will be used. Measurements will be made pre and post-treatment, one month after the last evaluation, the measurements will be made again for follow-up. The intervention will be one day a week for four consecutive weeks.

The data will be collected using a self-implementing questionnaire, these data will be transferred to an excel table and then transferred to SPSS 19.0 (SPSS Inc., Chicago, IL) and MedCalc 19.1 (MedCalc Software Bv, Ostend, Belgium, http: // wwww .medcalc.org; 2019) for the subsequent statistical analysis, the data being stripped of any direct reference to the subject to preserve confidentiality.

The descriptive analysis will be carried out with means and standard deviations for continuous variables, frequencies and percentages for categorical variables. The normality of the continuous variables will be calculated with the Kolmogorov-Smirnov test and the homocedasticity of the sample with the Levene test.

All the statistical analysis will be carried out with a confidence level of 95% (p <0.05), for the comparison of the two groups we will use the Student's t-test and the Chi-square test. Comparisons between treatment group and placebo group will be made using repeated measures analysis of variance and ANOVA, followed by Bonferroni to compare measures replicated over time.