Background: According to the International Association for the Study of Pain (IASP), the term
temporomandibular disorder (TMD) regards a subgroup of orofacial pain, the symptoms of which
include pain or discomfort in the temporomandibular joint, ears, masticatory muscles and neck
on one or both sides as well as joint sounds, limited mandibular movements or mandibular
deviation and difficulties chewing. Phototherapy, such as low level laser therapy (LLLT) and
light-emitting diode (LED) therapy, is one of the resources used to treatment muscle pain.
Thus, there is a need to investigate therapeutic resources that combine different wavelengths
as well as different light sources (LLLT and LED) in the same apparatus.
Question: The aim of the proposed study is to evaluate the effects of phototherapy on pain,
activity of the masticatory muscles (masseter and anterior temporal bilaterally) and joint
mobility in individuals with temporomandibular disorder (TMD). A further aim is to determine
the cumulative effect 24 and 48 hours after a six session.
Methods/Design: A placebo-controlled, double-blind, randomized, clinical trial will be
carried out involving 30 women between 18 and 40 years of age with a diagnosis of myogenous
TMD. The participants will then be randomly allocated to two groups totaling 15 individuals
per group. Group 1 submitted to a session of phototherapy with 39,27 Joules per point one
group will receive placebo therapy (0 Joules). The following assessment tools will be
administered on four separate occasions (baseline and immediately after, 24 h after and 48 h
after phototherapy). Pain intensity will be assessed using the visual analog scale for pain,
meter for range of movement, and electromyographic EMG analysis on the masseter and anterior
Discussion: The study will support the practice of evidence-based to the use of phototherapy
in individuals with a myogenous TMD. Data will be published after the study is completed.