A Retrospective Randomized Controlled Study Comparing the Effectiveness of Low-level Laser Therapy and Ultrasound Therapy in Reducing Pain and Increasing Maximum Mouth Opening in Forty-six Patients With Temporomandibular Disorders

Summary

Temporomandibular disorders (TMDs) are the most common cause of non-dental orofacial pain, involving the temporomandibular joint (TMJ), masticatory muscles, or associated structures. Globally, TMD is the second most prevalent musculoskeletal pain condition after low back pain. Epidemiological data show a high prevalence of TMD symptoms, particularly among women and Asian populations, with significant disease burden reported in Nepal. Conservative management remains the mainstay of TMD treatment, as evidence supporting surgical intervention is limited and inconclusive.

Among conservative modalities, physical therapies such as ultrasound therapy and low-level laser therapy (LLLT) have gained attention for pain reduction and functional improvement. Ultrasound therapy produces thermal and non-thermal effects that enhance blood flow, reduce muscle spasm, improve tissue extensibility, and promote healing. LLLT, through photobiomodulation, acts at the cellular level by increasing ATP production, reducing inflammatory mediators, enhancing collagen synthesis, and providing analgesic and anti-inflammatory effects.

Although several international studies have evaluated ultrasound and LLLT individually or in combination, limited studies have directly compared their effectiveness in TMD, and no such studies have been conducted in Nepal. Therefore, this study aims to compare the effectiveness of therapeutic ultrasound and LLLT in reducing pain and improving mouth opening in patients with TMD presenting to BPKIHS.

This was a retrospective randomized controlled study conducted at the Department of Oral Medicine and Radiology, College of Dental Surgery, BPKIHS. A total of 46 patients diagnosed with myalgia of masticatory muscles and/or TMJ arthralgia according to DC/TMD criteria were included using purposive sampling. Patients were allocated into two groups: Group A received low-level laser therapy (650 nm wavelength, 2 J/cm² for 3 minutes) and Group B received therapeutic ultrasound (1 MHz, 1.3 W/cm², continuous mode for 5 minutes). Five treatment sessions had been administered over two weeks.

Pain intensity was assessed using the Visual Analogue Scale (VAS) at each visit, while inter-incisal mouth opening was measured using a metallic scale at baseline and at the final visit.

Primary outcome measure was the difference in VAS scores in patients undergoing ultrasound therapy and low-level laser therapy for temporomandibular disorder before and after therapy.

Secondary outcome measures included the difference in inter-incisal mouth opening before and after therapy and the effectiveness of ultrasound therapy and low-level laser therapy in reducing pain in patients with arthralgia and myalgia.

Data were analyzed using SPSS version 11.5. Descriptive statistics were calculated, and inferential tests including independent and paired t-tests (or non-parametric equivalents), ANOVA/Kruskal-Wallis tests, and logistic regression were applied where appropriate. Ethical clearance was obtained from the Institutional Review Committee, BPKIHS with Ref. 20/080/081-IRC, Code no. IRC/2509/023.

Conditions

• Temporomandibular Disorders (TMD)
• Temporomandibular Joint Disorder

Interventions

DEVICE

Low-Level Laser Therapy

Low-level laser therapy delivered using a single-probe laser emitting infrared radiation at 650 nm, with an energy density of 2 J/cm² and output power of 80 mW for 3 minutes per session, applied to the area of maximum pain.

DEVICE

Ultrasound therapy

Therapeutic ultrasound delivered at a frequency of 1 MHz and intensity of 1.3 W/cm² in continuous mode for 5 minutes per side per session, applied to the affected temporomandibular region.

Sponsors & Collaborators

• B.P. Koirala Institute of Health Sciences

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2023-07-21

Primary Completion

2024-05-17

Completion

2024-11-20

Countries

• Nepal

Study Locations