[Placebo analgesia and sleep]

Effect of low-level gallium aluminum arsenide laser therapy on the chewing performance and pain perception of patients with systemic lupus erythematosus: A randomized controlled clinical trial

OBJECTIVE

To evaluate the effect of low-level laser therapy (LLLT) on pain intensity (PI) and chewing performance (CP) in systemic lupus erythematosus (SLE) patients with myogenic temporomandibular disorder (TMD).

METHODS

Ninety-one patients were randomly allocated to three groups: Group L (intervention), Group P (placebo), and Group C (control). Outcomes were PI (assessed with visual analog scale (VAS)) and CP (assessed with the geometric mean diameter (GMD) of crushed test food). Measurements were performed at T0 (before the LLLT), T1 (immediately after the LLLT), and T2 (1-month follow-up). Data were analyzed using Generalized Linear Models, Kruskal-Wallis, and Friedman tests.

RESULTS

For T1 and T2, Group L demonstrated the lowest values for both GMD (6283.7 ± 257.2 µm; 6382.7 ± 303.7 µm) and VAS (5;6) (p < 0.001).

CONCLUSION

LLLT was an effective therapeutic approach in reducing pain and improving CP for one month in SLE patients with myogenic TMD.

Effect of photobiomodulation therapy on painful temporomandibular disorders

To evaluate the effect of photobiomodulation therapy (PBMT) on painful temporomandibular disorders (TMD) patients in a randomized, double-blinded, placebo-controlled manner. Participants were divided into a masseter myalgia group (n = 88) and a temporomandibular joint (TMJ) arthralgia group (n = 87) according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Both groups randomly received PBMT or placebo treatment once a day for 7 consecutive days, one session. The PBMT was applied with a gallium-aluminum-arsenide (GaAlAs) laser (wavelength = 810 nm) at pre-determined points in the masseter muscle (6 J/cm², 3 regions, 60 s) or TMJ region (6 J/cm², 5 points, 30 s) according to their most painful site. Pain intensity was rated on a 0–10 numerical rating scale (NRS) and pressure pain thresholds (PPT) and mechanical sensitivity mapping were recorded before and after the treatment on day 1 and day 7. Jaw function was assessed by pain free jaw opening, maximum unassisted jaw opening, maximum assisted jaw opening, maximum protrusion and right and left excursion. Data were analyzed with a mixed model analysis of variance (ANOVA). Pain intensity in arthralgia patients decreased over time (P < 0.001) for both types of interventions, however, PBMT caused greater reduction in pain scores than placebo (P = 0.014). For myalgia patients, pain intensity decreased over time (P < 0.001) but without difference between interventions (P = 0.074). PPTs increased in both myalgia (P < 0.001) and TMJ arthralgia patients over time (P < 0.001) but without difference between interventions (P ≥ 0.614). Overall, PBMT was associated with marginally better improvements in range of motion compared to placebo in both myalgia and arthralgia patients. Pain intensity, sensory function and jaw movements improve after both PBMT and placebo treatments in myalgia and arthralgia patients indicating a substantial non-specific effect of PBMT.