Effects of Low-Level Laser Therapy on Mouth Opening and Surface Electromyography in Temporomandibular Disorders

A low-level gallium arsenide diode (Biolase, USA) at a 940 nm wavelength with 0.2 W output power and 2 J energy. The device was calibrated, and the probe was disinfected prior to every treatment.

The Masseter and Temporalis muscles will be bilaterally assessed with constant pressure to define tenderness.

LLLT applied perpendicular to each tender point of the intended muscles for 10 seconds with an energy density of 2.5 J/cm2.

Sessions are scheduled 3 days a week (every other day)

• A low-level gallium arsenide diode

A soft occlusal splint (vacuum-formed ) made from a 2-mm-thick elastic rubber sheets will be used.

Splints were individually designed ( in the out patient clinic of the college of dentistry) for the upper arch of each patient. An alginate imprint of the maxillary arch will be taken to fabricate a master cast of the maxilla.

A vacuum pressure device was utilized for molding the rubber sheets (13 x 13 cm /2-mm thickness).

Sheets were removed after it has been appropriately adjusted to the mold in the vacuum former. Edges will be properly trimmed, and the palate part is detached to obtain the end shape.

Participants are instructed to wear the splint at all times except during mealtimes and oral hygiene.

A vacuum-formed soft occlusal splint made from a 2-mm-thick elastic rubber sheets.

Participants are instructed to always wear the splint except during mealtimes and oral hygiene.

Active and passive mouth opening will be assessed by a Boley gauge (Electronic Digital Caliper, CE Company, Japan)

TOI= Passive opening mm -Maximum voluntary opening mm X 100 Passive opening mm +Maximum voluntary opening mm

For recording, a surface electromyograph (Myotronics-Noromed, Inc., Tukwila WA, USA), with 8-channels, simultaneous acquisition, common grounding to all channels, and filters of 50 Hz electromyography with disposable electrodes will be used.

Subjects will be seated on chairs with back and head rests to allow assessment from a relaxed position.

The right masseter (RM), left masseter (LM), right anterior temporal (RAT), left anterior temporal (LAT), right sternocleidomastoid (RSM), and left sternocleidomastoid (LSM) muscles were recorded. The sEMG recordings and muscle activity will be expressed as the root mean square (rms) of the amplitude, expressed in µV.

The pain VAS is a reliable measure of pain intensity with a 10 centimeters (100 mm) continuous scale attached by 2 verbal descriptors, one for each symptom extreme.

For pain intensity, the scale is most anchored by "no pain" (score of 0) and "pain as bad as it could be" or "worst imaginable pain" (score of 100).

The VAS only requires the ability to use a ruler to measure the distance to determine a score.