The effect of photobiomodulation auriculotherapy in the treatment of temporomandibular disorders: A double-blind randomized feasibility study

Introduction

Temporomandibular disorders (TMD) are considered the most common complaint associaetd with orofacial pain. A treatment approach for TMD is photobiomodulation auriculotherapy, however, a method that which still requires studies mainly with pulsed frequency.

Objective

To evaluate the feasibility of conducting a randomized clinical trial using pulsed frequency photobiomodulation auriculotherapy and determine the relevant sample size.

Methods

The study was a controlled randomized pilot study. Twenty one volunteers with TMD were randomized into experimental and placebo groups. The evaluation periods were pre-intervention and again after four weeks. The instruments used for the assessment were axis I (mandibular movement measurements [MMM]) and axis II (Graded Chronic Pain Scale [GCPS], Jaw Functional Limitation Scale [JFLS-8], The Patient Health Questionnaire [PHQ-4], and Generalized Anxiety Disorder [GAD-7]) from Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Mann–Whitney and Wilcoxon tests were used for comparison of groups. The intervention protocol was performed once a week for foour weeks.

Results

The GCPS question about “pain at this exact moment” indicated lower values for the treated group compared to the placebo group (U = 15.50; p = 0.005) after the intervention. The calculation of the total sample was 22 volunteers. The JFLS-8 variable showed no difference between the groups and the sample calculation ranged from 39 to 281 volunteers. The MMM showed no difference between the groups, and the calculation of the necessary sample ranged from 27 to 2.317. The variable PHQ-4 (U = 21.00; p = 0.02) and GAD-7 (U = 20.00; p = 0.02) showed differences between groups with type I error. The required sample was 22 volunteers for PHQ-4 and 25 for GAD-7.

Conclusion

We conclude that this study is feasible and that the required sample should be 11 volunteers for each group in the GCPS subitem “pain intensity at this exact moment”. We were able to find results for this GCPS subitem. However, for other variables we need 25 volunteers for GAD7 and 22 volunteers for PHQ-4. Other variables, such as JFLS-8 and MMM, made it impossible to conduct these scales for future studies.