Comparative effectiveness of Low-Level LASER Therapy of different wavelengths in patients with temporomandibular joint disorders: a randomized controlled trial

Objectives of the study: 1. To assess the effectiveness of low -level LASER therapy with three different wavelengths- 660 nm, 810 nm, and combined dual-wavelength (simultaneous 660 nm + 880 nm) in the management of temporomandibular joint disorders on the basis of changes in pain score using Numeric Rating Scale (NRS), mandibular range of motion, cervical range of motion and electromyographic studies. 2. To compare the effectiveness of three different wavelengths- 660 nm, 810 nm, and combined dual-wavelength (simultaneous 660 nm + 880 nm) amongst themselves.

Null Hypothesis: There is no difference in various treatment outcomes (e.g. changes in pain score using Numeric Rating Scale, mandibular range of motion, cervical range of motion and electromyographic studies) among low-level LASER therapy with three different wavelengths 660 nm, 810nm, and combined dual-wavelength (660 nm + 880 nm) in the treatment of temporomandibular disorders.

**Source of data:**Data will be collected from patients reporting to the Out-Patient Unit of Oral Medicine and Radiology in the Faculty of Dental Sciences, I.M.S., B.H.U. Patientsfulfilling the inclusion criteria will be selected. Diagnosis of TMD would be based on the patient’s history and clinical features.

Method of collection of data

Sampling technique- Simple Random Sampling

Sample size determination- Sample size was calculated with α = 0.05, power of study at 80% and Type II error 0.20 by substituting the values obtained in a previous study, in G*power 3.1.9.7 software. The sample size obtained was 25 per group. (Carrasco, Thaise Graciele et al. “Low intensity laser therapy in temporomandibular disorder: a phase II double-blind study.” Cranio : the journal of craniomandibular practice vol. 26,4 (2008): 274-81. doi:10.1179/crn.2008.037)

Study design- Randomized Controlled Trial. Samples will be of age 18 to 50 years. Matching will be done for age.

Materials-

1. Basic examination kit (kidney tray, explorer, mouth mirror, tweezers, stethoscope, mask, and disposable gloves)

2. Orthopantomogram

3. Digital callipers

4. Goniometer

5. Electromyography machine and associated armamentarium

6. Diode LASER device with 660 nm, 810 nm and dual wavelength settings with associated armamentarium

Methods

1. Diagnosis of Temporomandibular Disorders will be made on the basis of clinical findings in accordance with the latest version of the RDC/TMD.

2. The study and treatment protocol will be explained to the patient in brief and the informed consent will be taken.

3. Baseline scoring of pain using NRS, measurements of cervical mobility using goniometer, measurements of mandibular movement using digital callipers and electromyographic studies of sternocleidomastoid, masseter, temporalis and trapezius muscles will be done preoperatively by a trained observer.

4. Patients will be randomly assigned to one of the three study groups consisting of 25 subjects each- Group 1 (680 nm), Group 2 (810 nm) and Group 3 (dual wavelength).

5. Group 1 patients will be irradiated with 660 nm diode laser, continuous wave, contact mode with 200 mw power, 60 sec on each cm2 area i.e. 6J/ cm2. 2 sessions/week will be given for 4 weeks on bilateral TMJ, masseter, temporalis, trapezius and sternocleidomastoid muscles at predetermined points.

6. Group 2 patients will be irradiated with 810 nm diode laser, continuous wave, contact mode with 200 mW power, 60 sec on each cm2 area i.e. 6J/ cm2. 2 sessions/week will be given for 4 weeks on bilateral TMJ, masseter, temporalis, trapezius and sternocleidomastoid muscles at predetermined points.

7. Group 3 patients will be irradiated with dual wavelength diode laser (660 + 810 nm), continuous  wave, contact mode with 200 mw power, 60 sec on each cm2 area i.e. 6J/ cm2. 2 sessions/week will be given for 4 weeks on bilateral TMJ, masseter, temporalis, trapezius and sternocleidomastoid muscles at predetermined points.

8. Subjects of all the experimental groups will be instructed to use their respective treatments as the only management modalities.

9. Measurements of NRS, cervical range of motion, and mandibular range of motion will be taken at baseline, at the end of 1 week, 2 week, 3 week and 4 week.

10. Electromyographic studies of masseter, temporalis, trapezius and sternocleidomastoid muscles will be taken at baseline and at the end of 4 weeks.

11. Comparative evaluation and statistical analysis of all parameters will be done after data collection.