Abstract
Background and aims. Muscular pain in the facial region is the most common cause of facial pains.
Myofascial pain dysfunction syndrome (MPDS) is one of the most important facial muscle disorders comprising
of signs and symptoms including pain during function, tenderness in the muscles of mastication and
restricted jaw movement. Due to the lack of an accepted therapeutic approach, the purpose of this paper was
to find an effective treatment to decrease the pain of such patients. Considering the analgesic and antiinflammatory
action of laser therapy, the effects of low level laser (Ga-Al-As) in the treatment of MPDS
patients referred to Tehran University of Medical Sciences Faculty of Dentistry, were investigated in the
present study.
Materials and methods. This study was a quasi-experimental research. Twenty-two MPDS patients
were selected from those referred to Department of Oral Medicine, Tehran University of Medical Sciences
Faculty of Dentistry. Clinical examination was performed at six stages in the following order: prior to the
treatment, at 2 and 4 weeks after treatment, and monthly thereafter for a 3-months follow-up. All patients
underwent low-level laser therapy for 4 weeks (12 sessions). Variables such as pain severity, pain of cheek
region, pain frequency, tenderness of masticatory muscles, click, and mouth opening were evaluated at each
stage. Numerical variables were investigated using Analysis of Variance test for repeated measures whereas
ranking variables were studied by non-parametric Kruskal-Wallis test.
Results. At the end of treatment period, pain severity, pain of cheek region, pain frequency, tenderness of
masseter, temporalis, medial pterygoid, and lateral pterygoid muscles showed significant improvement as
compared with the commencement of any treatment which continued during the 3-months post-treatment
(p<0.05).
Conclusion. It was shown that low-level laser (Ga-Al-As) therapy had the efficacy to alleviate pain and
decrease the tenderness of masticatory muscles among MPDS patients through a continuous and regular
therapeutic program.