Fluence-dependent effects of low-level laser therapy in myofascial trigger spots on modulation of biochemicals associated with pain in a rabbit model.

Evidence strongly supports that low-level laser therapy (LLLT) is an effective physical modality for the treatment of pain associated with myofascial trigger points (MTrP). However, the effect of laser fluence (energy intensity in J/cm(2)) on biochemical regulation related to pain is unclear. To better understand the biochemical mechanisms modulated by high- and low-fluence LLLT at myofascial trigger spots (MTrSs; similar to human MTrPs) in skeletal muscles of rabbits, the levels of ß-endorphin (ß-ep), substance P (SP), tumor necrosis factor-α (TNF-α), and cyclooxygenase-2 (COX-2) were investigated in this study. New Zealand rabbits (2.5-3.0 kg in weight) were used in this study. High-fluence LLLT (27 J/cm(2)), low-fluence LLLT (4.5 J/cm(2)), or sham operations were applied on MTrSs of biceps femoris of rabbits for five sessions (one session per day). Effects of LLLT at two different fluences on biceps femoris, dorsal root ganglion (DRG), and serum were determined by ß-ep, SP, TNF-α, and COX-2 immunoassays. LLLT irradiation with fluences of 4.5 and 27 J/cm(2) at MTrSs can significantly reduce SP level in DRG. LLLT with lower fluence of 4.5 J/cm(2) exerted lower levels of TNF-α and COX-2 expression in laser-treated muscle, but LLLT with higher fluence of 27 J/cm(2) elevated the levels of ß-ep in serum, DRG, and muscle. This study demonstrated fluence-dependent biochemical effects of LLLT in an animal model on management of myofascial pain. The findings can contribute to the development of dosage guideline for LLLT for treating MTrP-induced pain.

Spirituality of chronic orofacial pain patients: case-control study.

The objective of this study was to investigate spirituality and blood parameters associated with stress in patients with facial musculoskeletal pain. Twenty-four women with chronic facial musculoskeletal pain (CFMP) and 24 healthy women were evaluated with a protocol for orofacial characteristics, research diagnostic criteria for temporomandibular disorders and the Spiritual Perspective Scale. Blood samples were collected to analyze blood count, cortisol, ACTH, C3, C4, thyroid hormones, total immunoglobulin, C-reactive protein and rheumatoid factor. The study group was more spiritualized than control group. Individuals with a high score of spirituality had less myofascial pain, less bruxism and fewer complaints. They also had lower levels of ACTH and IgE. Spirituality was higher in the study group and can be considered an important tool for coping with CFMP.

Interleukin-1beta, interleukin-1 receptor antagonist, and interleukin-1 soluble receptor II in temporomandibular joint synovial fluid from patients with chronic polyarthritides.

PURPOSE: The aim of this study was to investigate whether interleukin-1beta (IL-1beta), interleukin-1 receptor antagonist (IL-1ra), or soluble IL-1 receptor II (sIL-1RII) in synovial fluid or plasma is associated with joint pain or signs of tissue destruction in patients with temporomandibular joint (TMJ) involvement of polyarthritides. PATIENTS AND METHODS: Forty-three patients with TMJ involvement of polyarthritides were included. TMJ resting pain, tenderness to palpation, pressure pain threshold, pain on mandibular movement, and anterior open bite were assessed. TMJ synovial fluid samples and plasma were obtained for analysis of IL-1beta, IL-1ra, and sIL-1RII. RESULTS: IL-1beta was detected in 18% of the synovial fluid samples and in 44% of the plasma samples. The concentrations of IL-1ra in plasma were lower than in the synovial fluid, whereas the opposite condition was found for sIL-1-RII. IL-1ra in synovial fluid and plasma was associated with low intensity of TMJ pain. sIL-1RII in synovial fluid was associated with low degree of anterior open bite, whereas sIL-1RII in plasma was associated with widespread musculoskeletal pain, TMJ pain and tenderness, and decreased pressure pain threshold over the TMJ. CONCLUSION: IL-1ra and sIL-1RII are present in different proportions in TMJ synovial fluid and blood plasma from patients with TMJ involvement of polyarthritis. Both of these molecules seem to influence the clinical features of these forms of TMJ inflammation.