Effect of MLS(®) laser therapy with different dose regimes for the treatment of experimentally induced tendinopathy in sheep: pilot study

Occlusal splint and combined multiwave locked system laser therapy demonstrated differential patient-reported outcomes and clinical parameters: A randomized controlled trial in patients with temporomandibular disorder

PURPOSE

To evaluate the impact of occlusal splint plus laser therapy (OS + LT) compared with OS alone on the patient-reported outcomes and clinical parameters of patients with temporomandibular disorders (TMDs).

METHODS

Twenty-three patients with TMDs were randomly assigned to two treatment approaches: OS and OS + LT (multiwave locked system). The two outcomes were clinical parameters (mouth-opening distances, number of muscles and TMJs with pain) and patient-reported outcomes (pain score and oral health-related quality of life [OHRQoL] determined using the 14-item oral health impact profile [OHIP-14]). The outcomes were measured at four time points: baseline, 2 weeks, 1 and 3 months after treatment. According to DC/TMD Axis I classification, the participants were diagnosed as having pain only and pain with intraarticular joint disorder. Adjusting for age and sex, the outcome changes were analysed using generalized estimating models at a 5% significance level.

RESULTS

The pain-free mouth-opening distance of the patients who received OS + LT continuously increased from 2 weeks to 3 months. However, the value was significantly increased at 3 months in patients who received OS alone. The unassisted mouth-opening distance significantly increased after 3 months in both groups. In both treatment approaches, the number of muscles and TMJs with pain, as well as the pain and OHIP-14 scores gradually decreased from baseline to 3 months.

CONCLUSIONS

The patients who received OS and OS + LT demonstrated better OHRQoL and clinical parameters during 3 months after treatment. An improvement in the pain-free mouth-opening distance at 2 weeks was found only in OS plus LT group; however, this difference may not be clinically significant.

Histological, Physiological and Biomechanical Effects of Low-Level Laser Therapy on Tendon Healing in Animals and Humans: A Systematic Review

Low-level Laser Therapy (LLLT) was widely used in clinical practice for tendon disorders. However, the underlying mechanisms and effectiveness of LLLT in treating tendon injury remain unclear. Therefore, the present study was conducted aiming to summarize the evidence regarding the histological, physiological, and biomechanical effects of LLLT on tendon healing in animal and human models. Four databases were searched for relevant literature. Four independent reviewers screened abstracts and full-text articles, extracted relevant data, evaluated the risk of bias, and quantified the quality of evidence. Database searches yielded 1400 non-duplicated citations. Fifty-five studies were included (50 animal and five human studies). Animal studies revealed that LT had stimulating effects on collagen organization, collagen I and collagen II formation, matrix metalloproteinase (MMP)-8, transforming growth factor β1, vascular endothelial growth factor, hydroxyproline, maximum load, maximum elongation before breaking, and tendon stiffness. However, LLLT had inhibitory effects on the number of inflammatory cells, histological scores, relative amount of collagen III, cyclooxygenase-2, prostaglandin E2 (PGE2), interleukin-6, tumor necrosis factor-α, MMP-1, and MMP-3. Although one human study found that LLLT reduced the concentration of PGE2 in peritendinous tissue of the Achilles tendon, other human studies revealed that the effects of LLLT on the physiology and biomechanics of human tendons remained uncertain. LLLT facilitates tendon healing through various histological, physiological, and biomechanical effects in animal models. Only post-LLLT anti-inflammatory effects were found in human studies.

Large animal models for the study of tendinopathy

Tendinopathy has a high incidence in athletes and the aging population. It can cause pain and movement disorders, and is one of the most difficult problems in orthopedics. Animal models of tendinopathy provide potentially efficient and effective means to develop understanding of human tendinopathy and its underlying pathological mechanisms and treatments. The selection of preclinical models is essential to ensure the successful translation of effective and innovative treatments into clinical practice. Large animals can be used in both micro- and macro-level research owing to their similarity to humans in size, structure, and function. This article reviews the application of large animal models in tendinopathy regarding injuries to four tendons: rotator cuff, patellar ligament, Achilles tendon, and flexor tendon. The advantages and disadvantages of studying tendinopathy with large animal models are summarized. It is hoped that, with further development of animal models of tendinopathy, new strategies for the prevention and treatment of tendinopathy in humans will be developed.

Effect of class IV laser therapy and Pilates exercises on bone density and pain in primary osteoporosis: a randomised controlled trial

Background/aims

Osteoporosis is a systemic disorder characterised by a decrease in bone quality and density. This causes the bones to become weak and unable to withstand mild stresses, and the associated pain is made worse with activities. The aim of this study was to investigate the effect of class IV laser therapy and Pilates exercises on bone mineral density and pain in patients with primary osteoporosis.

Methods

A total of 60 patients with osteoporosis (40 women and 20 men) participated in this study. Their age ranged between 40 and 60 years. They were allocated randomly to three groups: Group A (n=20) received multiwave locked system laser therapy, group B (n=20) patients received Pilates exercises and group C (n=20) received multiwave locked system laser therapy and Pilates exercises. The treatment programme took place three times a week for 8 weeks. Bone mineral density of the lumbar spine (L1–L4) was measured by dual-energy X-ray absorptiometry and pain intensity during activities was measured by using the Numeric Pain Rating Scale. Evaluation of lumbar bone mineral density and pain intensity were performed before and after 8 weeks.

Results

The statistical analysis of this study revealed there was a significant increase of T-scores post-treatment compared to pre-treatment within group A (P=0.0001; P<0.05), group B (P=0.0001; P<0.05), and group C (P=0.0001), with improvement percentages of 19.59, 34.69 and 50.66% respectively. There was a decrease of pain intensity during activities post-treatment compared to pre-treatment within group A (P=0.0001; P<0.05), group B (P=0.0001; P<0.05) and group C (P=0.0001), with improvement percentages of 41.28, 54.39 and 70.09% respectively.

Conclusions

Class IV laser therapy and Pilates exercises are useful therapeutic modalities to increase bone mineral density and decrease pain in patients with osteoporosis, but combining them is more effective than using them separately.

Photobiomodulation therapy increases collagen II after tendon experimental injury

A tendon is a mechanosensitive tissue that transmits muscle-derived forces to bones. Photobiomodulation (PBM), also known as low-level laser therapy (LLLT), has been used in therapeutic approaches in tendon lesions, but uncertainties regarding its mechanisms of action have prevented its widespread use. We investigated the response of PBM therapy in experimental lesions of the Achilles tendon in rats. Thirty adult male Wistar rats weighing 250 to 300 g were surgically submitted to bilateral partial transverse section of the Achilles tendon. The right tendon was treated with PBM, whereas the left tendon served as a control. On the third postoperative day, the rats were divided into three experimental groups consisting of ten rats each, which were treated with PBM (Konf, Aculas - HB 750), 780 nm and 80 mW for 20 seconds, three times/week for 7, 14 and 28 days. The rats were sacrificed at the end of the therapeutic time period. The Sca-1 was examined by immunohistochemistry and histomorphometry, and COLA1, COLA2 and COLA3 gene expression was examined by qRT-PCR. COLA2 gene expression was higher in PBM treated tendons than in the control group. The histomorphometric analysis coincided with increased number of mesenchymal cells, characterized by Sca-1 expression in the lesion region (p<0.001). PBM effectively interferes in tendon tissue repair after injury by stimulating mesenchymal cell proliferation and the synthesis of collagen type II, which is suggested to provide structural support to the interstitial tissues during the healing process of the Achilles tendon. Further studies are needed to confirm the role of PBM in tendon healing.

Photobiomodulation does not influence maturation and mildly improves functional healing of mouse achilles tendons

Tendon rupture can occur at any age and is commonly treated nonoperatively, yet can result in persisting symptoms. Thus, a need exists to improve nonoperative treatments of injured tendons. Photobiomodulation (PBM) therapy has shown promise in the clinic and is hypothesized to stimulate mitochondrial-related metabolism and improve healing. However, the effect of PBM therapy on mitochondrial function during tendon maturation and healing are unknown, and its effect on tendon structure and function remain unclear. In this study, near-infrared light (980:810 nm blend, 2.5 J/cm² ) was applied at low (30 mW/cm² ) or high (300 mW/cm² ) irradiance to unilateral Achilles tendons of CD-1 mice during postnatal growth (maturation) as well as adult mice with bilateral Achilles tenotomy (healing). The chronic effect of PBM therapy on tendon structure and function was determined using histology and mechanics, and the acute effect of PBM therapy on mitochondrial-related gene expression was assessed. During maturation and healing, collagen alignment, cell number, and nuclear shape were unaffected by chronic PBM therapy. We found a sex-dependent effect of PBM therapy during healing on mechanical outcomes (eg, increased stiffness and Young's modulus for PBM-treated females, and increased strain at ultimate stress for PBM-treated males). Mitochondria-related gene expression was marginally influenced by PBM therapy for both maturation and healing studies. This study was the first to implement PBM therapy during both growth and healing of the murine tendon. PBM therapy resulted in marginal and sex-dependent effects on the murine tendon. Clinical significance: PBM may be beneficial for tendon healing because functional remodeling improves without adverse effects.

A comparison trial between three treatment modalities for the management of myofascial pain of jaw muscles: A preliminary study

OBJECTIVES

To compare three treatment modalities for the management of myofascial pain of jaw muscles.

METHODS

Thirty (N = 30) patients with low pain-related impairment were randomly assigned to receive laser therapy (LST), oral appliance therapy (OA), or counseling (CSL). Visual Analog Scale (VAS) pain levels and the Muscular Index (MI) of the Craniomandibular Index were the outcome variables, which were assessed at baseline, at three weeks, three months, and six months.

RESULTS

At six months, improvement in the MI was maintained both in the LST (p = .025) and OA groups (p < .001). As for VAS values, positive changes were still shown for LST (p = .001), and were also shown for the OA (p = .002) and CSL groups (p = .048).

CONCLUSIONS

Despite differences in the short-term effectiveness of LST and OA, with respect to CSL alone, all three treatment groups improved at six months. This suggests that active treatments should be directed to maximize the positive changes in the short-term period.

Tenogenic induction of equine mesenchymal stem cells by means of growth factors and low-level laser technology

Tendons regenerate poorly due to a dense extracellular matrix and low cellularity. Cellular therapies aim to improve tendon repair using mesenchymal stem cells and tenocytes; however, a current limitation is the low proliferative potential of tenocytes in cases of severe trauma. The purpose of this study was to develop a method useful in veterinary medicine to improve the differentiation of Peripheral Blood equine mesenchymal stem cells (PB-MSCs) into tenocytes. PB-MSCs were used to study the effects of the addition of some growth factors (GFs) as TGFβ3 (transforming growth factor), EGF2 (Epidermal growth factor), bFGF2 (Fibroblast growth factor) and IGF-1 (insulin-like growth factor) in presence or without Low Level Laser Technology (LLLT) on the mRNA expression levels of genes important in the tenogenic induction as Early Growth Response Protein-1 (EGR1), Tenascin (TNC) and Decorin (DCN). The singular addition of GFs did not show any influence on the mRNA expression of tenogenic genes whereas the specific combinations that arrested cell proliferation in favour of differentiation were the following: bFGF2 + TGFβ3 and bFGF2 + TGFβ3 + LLLT. Indeed, the supplement of bFGF2 and TGFβ3 significantly upregulated the expression of Early Growth Response Protein-1 and Decorin, while the use of LLLT induced a significant increase of Tenascin C levels. In conclusion, the present study might furnish significant suggestions for developing an efficient approach for tenocyte induction since the external administration of bFGF2 and TGFβ3, along with LLLT, influences the differentiation of PB-MSCs towards the tenogenic fate.