Low intensity laser therapy (LILT) has been widely applied in pain relief in several clinical situations. With the advent of new LED-based (light emitting diode) light sources, the need of further clinical experiments aiming to compare the effectiveness between them is paramount.

Aims: Low intensity laser therapy (LILT) has been widely applied in pain relief in several clinical situations. With the advent of new LED-based (light emitting diode)light sources, the need of further clinical experiments aiming to compare the effectiveness between them is paramount. Method: This study proposes an evaluation of analgesic effect in TMD (temporomandibular disorders) using two different LEDs systems, one emitting at the spectral band of red (630 +/-5 nm) and the other at infrared band (850 +/-5 nm), and compare the results with a laser treated control group (780nm diode laser using 105.7 J/cm2). Mandibular range of motion and report of pain were evaluated via appropriate equipment developed to do this end. Power output was 150mW, tip area was 0.5 cm² for both sources. Fluency or dose chosen was 18 J/cm² for each point of application, around the TMJ, on both sides. Five points were irradiated on TMJ, temporal and masseter muscles. Eight irradiation sessions were done and follow up was performed 7 and 30 days, after last session. Thirty patients were enrolled and they were selected randomly for each treatment, resulting in 10 patients per group (infrared LED, red LED and Control Group using infrared Laser).

Inclusion Criteria:

Thirty patients (from 18 to 50 years old) presenting signs and symptoms of TMD were selected to participate in the study. The patients received care at a private dental office in Ribeirao Preto, São Paulo, Brazil (NILO- Integrated Center for Laser in Dentistry). The patients´ age ranged from 18 to 40 years old, being 08 male and 22 female. The signs and symptoms evaluated by a trained professional were as follow: pain during palpation in the TMJ area, pain on associated muscles (masseter and temporal), and limited or painful jaw movement with impaired oral aperture.

Exclusion Criteria:

The exclusion criteria were patients whom where currently under orthodontic and/or orthopedic treatment, degenerative joint disease, patients who were under systemic medication with anti-inflammatory drugs, analgesic treatment, muscle relaxant and corticosteroids.

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