Low-level Laser Therapy on Temporomandibular Disorder

The purpose of this study is to assess the effect of low-level laser on pain, occlusal contacts, mandibular movements and electromyography activity in the masseter and temporal muscles in adolescents with TMD.

A randomized, controlled, double-blind, clinical trial will be carried out. Adolescents aged 15 to 18 years will answer the questionnaire of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD)and a specific clinical exam of RDC/TMD will also be carried out for the diagnosis of temporomandibular disorder (TMD), prior to any intervention. They will also be submitted to electromyographic analysis of the masseter muscles and anterior bundle of the temporal muscles bilaterally for the determination of TMD.

The type of occlusion of those participants will be determined by the clinical examination based on the Angle classification and the occlusal contact points will be recorded using T-Scan III.

Before the intervention, the mandibular range of motion will be assessed by the register of maximum voluntary mouth opening, maximum passive mouth opening and excursion as well as the record pain upon palpation of the masseter and temporal muscles using a visual analog scale.

The volunteers diagnosed with TMD will be divided into four groups and two sessions of LLLT or placebo treatment will be carried out over six weeks. One group will receive low-level laser (LLL) treatment on temporomandibular joint(TMJ) region, one will receive LLL treatment at masseter and temporal muscles, one will receive mixed application of LLL (muscles and TMJ) and the other group will receive placebo treatment.

After the last session of LLL treatment the electromyographic analysis, the record of occlusal contact points, mandibular range of motion and pain upon palpation will be carried out. 30 days following the last session the occlusal contact points, mandibular range of motion and pain upon palpation will be recorded.

Individuals with dentofacial anomalies, incomplete permanent dentition to the 2nd molar, currently undergoing orthodontic or orthopedic treatment of the jaws, currently undergoing psychological treatment or physical therapy and making use of a muscle relaxant, anti-inflammatory agent or bite plate will be excluded from the study.

The data will be submitted to descriptive statistical analysis. The chi-square test and Fisher's exact test will be used for the determination of associations among the categorical variables. The Student's t-test and analysis of variance will be used for the comparison of mean electromyographic signals. Pearson's correlation coefficients will be calculated for the analysis of correlations among the continuous variables.

Eligibility Criteria:
Inclusion Criteria:

* Individuals aged 15 to 18 years with diagnosis of TMD and a signed statement of informed consent will be included in the study.

Exclusion Criteria:

* Individuals with dentofacial anomalies, incomplete permanent dentition to the 2nd molar, currently undergoing orthodontic or orthopedic treatment of the jaws, currently undergoing psychological treatment or physical therapy and making use of a muscle relaxant, anti-inflammatory agent or bite plate will be excluded from the study.