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

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

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

This is a one year followup study that aims to assess the efficacy of low level laser therapy (LLLT) on pain, mouth opening and masticatory muscle activity in cases of temporomandibular dysfunction (TMD) as compared to soft occlusive splints.

A prospective, parallel randomized, controlled study will be conducted at the outpatient university clinic. Participant recruitment started following approval from the Ethics Committee .The patients will participate in the study after signing an informed consent form prior to data collection. Per inclusion criteria, subjects included are females less than 30 years of age, diagnosed with unilateral arthrogenous TMD, having complete permanent dentition and showing normal occlusion. Prior to participating in any study-related procedures, participants read and signed the informed consent form approved by the Institutional Review Board. Participants will be divided into three groups; three groups: LLLT (Group A); soft occlusive splint therapy OST (Group B); waitlist as controls (Group C). Outcome measures: TMJ opening index (TOI), VAS, sEMG. Participants were not given information on which treatment they were receiving; they were only told that they could receive one of two different treatment techniques. Sessions were scheduled 3 days a week (every other day) for a total of 10 sessions

Parallel Assignment A prospective, parallel-group, randomized clinical trial participants will be randomly assigned to the control group or one of the 2 intervention groups. One group received low level laser therapy (gallium arsenide diode ) while the other received the soft occusive splint. The control group was considered as a wait list for laser treatment aand did not recieve any treatment during the intervention period.

The participants as well as The assessor, who took the measurements for both the intervention and control groups, was blinded to the subject's group, while the treating therapist was not blinded to the treatment intervention.

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 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.

This group will be a wait list group recieving no intervention except for the regular analgesic prescribed by the reffering dentist

940 nm wavelength with 0.2 W output power and 2 J energy applied for 10 seconds with an energy density of 2.5 J/cm2.

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.

Inclusion Criteria: Females less than 30 years of age, Diagnosed with unilateral myogenous TMD, Having complete permanent dentition Showing normal occlusion Exclusion Criteria: Prior experience of Laser therapy, Systemic diseases (rheumatoid arthritis, ankylosing spondylitis, diabetes… etc. History of trauma in the TMJ or cervical regions; Neurological disorders, Muscular diseases; Cervical pain; Bruxism, Pregnancy; Currently on medication (analgesic, anti-inflammatory, muscle relaxants or anti- depressants) Current use of dental prosthetics; Previous orthodontal treatments; or Fixed restorations affecting occlusal surfaces.